mirror of
https://github.com/torvalds/linux.git
synced 2024-11-02 10:11:36 +00:00
66304207cd
Pull i2c updates from Wolfram Sang:
"Here is the I2C pull request for 4.8:
- the core and i801 driver gained support for SMBus Host Notify
- core support for more than one address in DT
- i2c_add_adapter() has now better error messages. We can remove all
error messages from drivers calling it as a next step.
- bigger updates to rk3x driver to support rk3399 SoC
- the at24 eeprom driver got refactored and can now read special
variants with unique serials or fixed MAC addresses.
The rest is regular driver updates and bugfixes"
* 'i2c/for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (66 commits)
i2c: i801: use IS_ENABLED() instead of checking for built-in or module
Documentation: i2c: slave: give proper example for pm usage
Documentation: i2c: slave: describe buffer problems a bit better
i2c: bcm2835: Don't complain on -EPROBE_DEFER from getting our clock
i2c: i2c-smbus: drop useless stubs
i2c: efm32: fix a failure path in efm32_i2c_probe()
Revert "i2c: core: Cleanup I2C ACPI namespace"
Revert "i2c: core: Add function for finding the bus speed from ACPI"
i2c: Update the description of I2C_SMBUS
i2c: i2c-smbus: fix i2c_handle_smbus_host_notify documentation
eeprom: at24: tweak the loop_until_timeout() macro
eeprom: at24: add support for at24mac series
eeprom: at24: support reading the serial number for 24csxx
eeprom: at24: platform_data: use BIT() macro
eeprom: at24: split at24_eeprom_write() into specialized functions
eeprom: at24: split at24_eeprom_read() into specialized functions
eeprom: at24: hide the read/write loop behind a macro
eeprom: at24: call read/write functions via function pointers
eeprom: at24: coding style fixes
eeprom: at24: move at24_read() below at24_eeprom_write()
...
3410 lines
91 KiB
C
3410 lines
91 KiB
C
/* i2c-core.c - a device driver for the iic-bus interface */
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/* ------------------------------------------------------------------------- */
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/* Copyright (C) 1995-99 Simon G. Vogl
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details. */
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/* ------------------------------------------------------------------------- */
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/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
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All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
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SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and
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Jean Delvare <jdelvare@suse.de>
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Mux support by Rodolfo Giometti <giometti@enneenne.com> and
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Michael Lawnick <michael.lawnick.ext@nsn.com>
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OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de>
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(based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and
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(c) 2013 Wolfram Sang <wsa@the-dreams.de>
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I2C ACPI code Copyright (C) 2014 Intel Corp
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Author: Lan Tianyu <tianyu.lan@intel.com>
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I2C slave support (c) 2014 by Wolfram Sang <wsa@sang-engineering.com>
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*/
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#define pr_fmt(fmt) "i2c-core: " fmt
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#include <dt-bindings/i2c/i2c.h>
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#include <asm/uaccess.h>
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#include <linux/acpi.h>
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#include <linux/clk/clk-conf.h>
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#include <linux/completion.h>
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/errno.h>
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#include <linux/gpio.h>
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#include <linux/hardirq.h>
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#include <linux/i2c.h>
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#include <linux/idr.h>
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#include <linux/init.h>
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#include <linux/irqflags.h>
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#include <linux/jump_label.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/of_device.h>
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#include <linux/of.h>
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#include <linux/of_irq.h>
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#include <linux/pm_domain.h>
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#include <linux/pm_runtime.h>
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#include <linux/pm_wakeirq.h>
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#include <linux/property.h>
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#include <linux/rwsem.h>
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#include <linux/slab.h>
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#include "i2c-core.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/i2c.h>
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#define I2C_ADDR_OFFSET_TEN_BIT 0xa000
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#define I2C_ADDR_OFFSET_SLAVE 0x1000
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/* core_lock protects i2c_adapter_idr, and guarantees
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that device detection, deletion of detected devices, and attach_adapter
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calls are serialized */
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static DEFINE_MUTEX(core_lock);
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static DEFINE_IDR(i2c_adapter_idr);
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static struct device_type i2c_client_type;
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static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
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static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE;
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static bool is_registered;
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void i2c_transfer_trace_reg(void)
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{
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static_key_slow_inc(&i2c_trace_msg);
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}
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void i2c_transfer_trace_unreg(void)
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{
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static_key_slow_dec(&i2c_trace_msg);
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}
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#if defined(CONFIG_ACPI)
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struct acpi_i2c_handler_data {
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struct acpi_connection_info info;
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struct i2c_adapter *adapter;
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};
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struct gsb_buffer {
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u8 status;
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u8 len;
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union {
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u16 wdata;
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u8 bdata;
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u8 data[0];
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};
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} __packed;
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struct acpi_i2c_lookup {
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struct i2c_board_info *info;
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acpi_handle adapter_handle;
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acpi_handle device_handle;
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};
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static int acpi_i2c_fill_info(struct acpi_resource *ares, void *data)
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{
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struct acpi_i2c_lookup *lookup = data;
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struct i2c_board_info *info = lookup->info;
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struct acpi_resource_i2c_serialbus *sb;
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acpi_status status;
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if (info->addr || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
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return 1;
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sb = &ares->data.i2c_serial_bus;
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if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C)
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return 1;
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status = acpi_get_handle(lookup->device_handle,
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sb->resource_source.string_ptr,
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&lookup->adapter_handle);
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if (!ACPI_SUCCESS(status))
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return 1;
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info->addr = sb->slave_address;
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if (sb->access_mode == ACPI_I2C_10BIT_MODE)
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info->flags |= I2C_CLIENT_TEN;
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return 1;
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}
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static int acpi_i2c_get_info(struct acpi_device *adev,
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struct i2c_board_info *info,
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acpi_handle *adapter_handle)
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{
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struct list_head resource_list;
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struct resource_entry *entry;
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struct acpi_i2c_lookup lookup;
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int ret;
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if (acpi_bus_get_status(adev) || !adev->status.present ||
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acpi_device_enumerated(adev))
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return -EINVAL;
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memset(info, 0, sizeof(*info));
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info->fwnode = acpi_fwnode_handle(adev);
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memset(&lookup, 0, sizeof(lookup));
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lookup.device_handle = acpi_device_handle(adev);
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lookup.info = info;
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/* Look up for I2cSerialBus resource */
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INIT_LIST_HEAD(&resource_list);
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ret = acpi_dev_get_resources(adev, &resource_list,
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acpi_i2c_fill_info, &lookup);
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acpi_dev_free_resource_list(&resource_list);
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if (ret < 0 || !info->addr)
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return -EINVAL;
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*adapter_handle = lookup.adapter_handle;
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/* Then fill IRQ number if any */
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ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
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if (ret < 0)
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return -EINVAL;
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resource_list_for_each_entry(entry, &resource_list) {
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if (resource_type(entry->res) == IORESOURCE_IRQ) {
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info->irq = entry->res->start;
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break;
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}
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}
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acpi_dev_free_resource_list(&resource_list);
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strlcpy(info->type, dev_name(&adev->dev), sizeof(info->type));
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return 0;
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}
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static void acpi_i2c_register_device(struct i2c_adapter *adapter,
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struct acpi_device *adev,
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struct i2c_board_info *info)
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{
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adev->power.flags.ignore_parent = true;
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acpi_device_set_enumerated(adev);
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if (!i2c_new_device(adapter, info)) {
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adev->power.flags.ignore_parent = false;
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dev_err(&adapter->dev,
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"failed to add I2C device %s from ACPI\n",
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dev_name(&adev->dev));
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}
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}
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static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level,
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void *data, void **return_value)
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{
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struct i2c_adapter *adapter = data;
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struct acpi_device *adev;
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acpi_handle adapter_handle;
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struct i2c_board_info info;
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if (acpi_bus_get_device(handle, &adev))
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return AE_OK;
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if (acpi_i2c_get_info(adev, &info, &adapter_handle))
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return AE_OK;
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if (adapter_handle != ACPI_HANDLE(&adapter->dev))
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return AE_OK;
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acpi_i2c_register_device(adapter, adev, &info);
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return AE_OK;
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}
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#define ACPI_I2C_MAX_SCAN_DEPTH 32
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/**
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* acpi_i2c_register_devices - enumerate I2C slave devices behind adapter
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* @adap: pointer to adapter
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*
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* Enumerate all I2C slave devices behind this adapter by walking the ACPI
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* namespace. When a device is found it will be added to the Linux device
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* model and bound to the corresponding ACPI handle.
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*/
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static void acpi_i2c_register_devices(struct i2c_adapter *adap)
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{
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acpi_status status;
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if (!has_acpi_companion(&adap->dev))
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return;
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status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
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ACPI_I2C_MAX_SCAN_DEPTH,
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acpi_i2c_add_device, NULL,
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adap, NULL);
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if (ACPI_FAILURE(status))
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dev_warn(&adap->dev, "failed to enumerate I2C slaves\n");
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}
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static int acpi_i2c_match_adapter(struct device *dev, void *data)
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{
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struct i2c_adapter *adapter = i2c_verify_adapter(dev);
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if (!adapter)
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return 0;
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return ACPI_HANDLE(dev) == (acpi_handle)data;
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}
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static int acpi_i2c_match_device(struct device *dev, void *data)
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{
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return ACPI_COMPANION(dev) == data;
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}
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static struct i2c_adapter *acpi_i2c_find_adapter_by_handle(acpi_handle handle)
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{
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struct device *dev;
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dev = bus_find_device(&i2c_bus_type, NULL, handle,
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acpi_i2c_match_adapter);
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return dev ? i2c_verify_adapter(dev) : NULL;
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}
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static struct i2c_client *acpi_i2c_find_client_by_adev(struct acpi_device *adev)
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{
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struct device *dev;
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dev = bus_find_device(&i2c_bus_type, NULL, adev, acpi_i2c_match_device);
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return dev ? i2c_verify_client(dev) : NULL;
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}
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static int acpi_i2c_notify(struct notifier_block *nb, unsigned long value,
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void *arg)
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{
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struct acpi_device *adev = arg;
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struct i2c_board_info info;
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acpi_handle adapter_handle;
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struct i2c_adapter *adapter;
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struct i2c_client *client;
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switch (value) {
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case ACPI_RECONFIG_DEVICE_ADD:
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if (acpi_i2c_get_info(adev, &info, &adapter_handle))
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break;
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adapter = acpi_i2c_find_adapter_by_handle(adapter_handle);
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if (!adapter)
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break;
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acpi_i2c_register_device(adapter, adev, &info);
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break;
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case ACPI_RECONFIG_DEVICE_REMOVE:
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if (!acpi_device_enumerated(adev))
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break;
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client = acpi_i2c_find_client_by_adev(adev);
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if (!client)
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break;
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i2c_unregister_device(client);
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put_device(&client->dev);
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break;
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}
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return NOTIFY_OK;
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}
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static struct notifier_block i2c_acpi_notifier = {
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.notifier_call = acpi_i2c_notify,
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};
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#else /* CONFIG_ACPI */
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static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) { }
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extern struct notifier_block i2c_acpi_notifier;
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#endif /* CONFIG_ACPI */
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#ifdef CONFIG_ACPI_I2C_OPREGION
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static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
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u8 cmd, u8 *data, u8 data_len)
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{
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struct i2c_msg msgs[2];
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int ret;
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u8 *buffer;
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buffer = kzalloc(data_len, GFP_KERNEL);
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if (!buffer)
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return AE_NO_MEMORY;
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msgs[0].addr = client->addr;
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msgs[0].flags = client->flags;
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msgs[0].len = 1;
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msgs[0].buf = &cmd;
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msgs[1].addr = client->addr;
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msgs[1].flags = client->flags | I2C_M_RD;
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msgs[1].len = data_len;
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msgs[1].buf = buffer;
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ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
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if (ret < 0)
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dev_err(&client->adapter->dev, "i2c read failed\n");
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else
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memcpy(data, buffer, data_len);
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kfree(buffer);
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return ret;
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}
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static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
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u8 cmd, u8 *data, u8 data_len)
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{
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|
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struct i2c_msg msgs[1];
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u8 *buffer;
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int ret = AE_OK;
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buffer = kzalloc(data_len + 1, GFP_KERNEL);
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if (!buffer)
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return AE_NO_MEMORY;
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buffer[0] = cmd;
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memcpy(buffer + 1, data, data_len);
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msgs[0].addr = client->addr;
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msgs[0].flags = client->flags;
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msgs[0].len = data_len + 1;
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msgs[0].buf = buffer;
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ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
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if (ret < 0)
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dev_err(&client->adapter->dev, "i2c write failed\n");
|
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|
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kfree(buffer);
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return ret;
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|
}
|
|
|
|
static acpi_status
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acpi_i2c_space_handler(u32 function, acpi_physical_address command,
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u32 bits, u64 *value64,
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void *handler_context, void *region_context)
|
|
{
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struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
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struct acpi_i2c_handler_data *data = handler_context;
|
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struct acpi_connection_info *info = &data->info;
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struct acpi_resource_i2c_serialbus *sb;
|
|
struct i2c_adapter *adapter = data->adapter;
|
|
struct i2c_client *client;
|
|
struct acpi_resource *ares;
|
|
u32 accessor_type = function >> 16;
|
|
u8 action = function & ACPI_IO_MASK;
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|
acpi_status ret;
|
|
int status;
|
|
|
|
ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
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|
if (ACPI_FAILURE(ret))
|
|
return ret;
|
|
|
|
client = kzalloc(sizeof(*client), GFP_KERNEL);
|
|
if (!client) {
|
|
ret = AE_NO_MEMORY;
|
|
goto err;
|
|
}
|
|
|
|
if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) {
|
|
ret = AE_BAD_PARAMETER;
|
|
goto err;
|
|
}
|
|
|
|
sb = &ares->data.i2c_serial_bus;
|
|
if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) {
|
|
ret = AE_BAD_PARAMETER;
|
|
goto err;
|
|
}
|
|
|
|
client->adapter = adapter;
|
|
client->addr = sb->slave_address;
|
|
|
|
if (sb->access_mode == ACPI_I2C_10BIT_MODE)
|
|
client->flags |= I2C_CLIENT_TEN;
|
|
|
|
switch (accessor_type) {
|
|
case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
|
|
if (action == ACPI_READ) {
|
|
status = i2c_smbus_read_byte(client);
|
|
if (status >= 0) {
|
|
gsb->bdata = status;
|
|
status = 0;
|
|
}
|
|
} else {
|
|
status = i2c_smbus_write_byte(client, gsb->bdata);
|
|
}
|
|
break;
|
|
|
|
case ACPI_GSB_ACCESS_ATTRIB_BYTE:
|
|
if (action == ACPI_READ) {
|
|
status = i2c_smbus_read_byte_data(client, command);
|
|
if (status >= 0) {
|
|
gsb->bdata = status;
|
|
status = 0;
|
|
}
|
|
} else {
|
|
status = i2c_smbus_write_byte_data(client, command,
|
|
gsb->bdata);
|
|
}
|
|
break;
|
|
|
|
case ACPI_GSB_ACCESS_ATTRIB_WORD:
|
|
if (action == ACPI_READ) {
|
|
status = i2c_smbus_read_word_data(client, command);
|
|
if (status >= 0) {
|
|
gsb->wdata = status;
|
|
status = 0;
|
|
}
|
|
} else {
|
|
status = i2c_smbus_write_word_data(client, command,
|
|
gsb->wdata);
|
|
}
|
|
break;
|
|
|
|
case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
|
|
if (action == ACPI_READ) {
|
|
status = i2c_smbus_read_block_data(client, command,
|
|
gsb->data);
|
|
if (status >= 0) {
|
|
gsb->len = status;
|
|
status = 0;
|
|
}
|
|
} else {
|
|
status = i2c_smbus_write_block_data(client, command,
|
|
gsb->len, gsb->data);
|
|
}
|
|
break;
|
|
|
|
case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
|
|
if (action == ACPI_READ) {
|
|
status = acpi_gsb_i2c_read_bytes(client, command,
|
|
gsb->data, info->access_length);
|
|
if (status > 0)
|
|
status = 0;
|
|
} else {
|
|
status = acpi_gsb_i2c_write_bytes(client, command,
|
|
gsb->data, info->access_length);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
|
|
accessor_type, client->addr);
|
|
ret = AE_BAD_PARAMETER;
|
|
goto err;
|
|
}
|
|
|
|
gsb->status = status;
|
|
|
|
err:
|
|
kfree(client);
|
|
ACPI_FREE(ares);
|
|
return ret;
|
|
}
|
|
|
|
|
|
static int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
|
|
{
|
|
acpi_handle handle;
|
|
struct acpi_i2c_handler_data *data;
|
|
acpi_status status;
|
|
|
|
if (!adapter->dev.parent)
|
|
return -ENODEV;
|
|
|
|
handle = ACPI_HANDLE(adapter->dev.parent);
|
|
|
|
if (!handle)
|
|
return -ENODEV;
|
|
|
|
data = kzalloc(sizeof(struct acpi_i2c_handler_data),
|
|
GFP_KERNEL);
|
|
if (!data)
|
|
return -ENOMEM;
|
|
|
|
data->adapter = adapter;
|
|
status = acpi_bus_attach_private_data(handle, (void *)data);
|
|
if (ACPI_FAILURE(status)) {
|
|
kfree(data);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
status = acpi_install_address_space_handler(handle,
|
|
ACPI_ADR_SPACE_GSBUS,
|
|
&acpi_i2c_space_handler,
|
|
NULL,
|
|
data);
|
|
if (ACPI_FAILURE(status)) {
|
|
dev_err(&adapter->dev, "Error installing i2c space handler\n");
|
|
acpi_bus_detach_private_data(handle);
|
|
kfree(data);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
acpi_walk_dep_device_list(handle);
|
|
return 0;
|
|
}
|
|
|
|
static void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
|
|
{
|
|
acpi_handle handle;
|
|
struct acpi_i2c_handler_data *data;
|
|
acpi_status status;
|
|
|
|
if (!adapter->dev.parent)
|
|
return;
|
|
|
|
handle = ACPI_HANDLE(adapter->dev.parent);
|
|
|
|
if (!handle)
|
|
return;
|
|
|
|
acpi_remove_address_space_handler(handle,
|
|
ACPI_ADR_SPACE_GSBUS,
|
|
&acpi_i2c_space_handler);
|
|
|
|
status = acpi_bus_get_private_data(handle, (void **)&data);
|
|
if (ACPI_SUCCESS(status))
|
|
kfree(data);
|
|
|
|
acpi_bus_detach_private_data(handle);
|
|
}
|
|
#else /* CONFIG_ACPI_I2C_OPREGION */
|
|
static inline void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
|
|
{ }
|
|
|
|
static inline int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
|
|
{ return 0; }
|
|
#endif /* CONFIG_ACPI_I2C_OPREGION */
|
|
|
|
/* ------------------------------------------------------------------------- */
|
|
|
|
static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
|
|
const struct i2c_client *client)
|
|
{
|
|
while (id->name[0]) {
|
|
if (strcmp(client->name, id->name) == 0)
|
|
return id;
|
|
id++;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static int i2c_device_match(struct device *dev, struct device_driver *drv)
|
|
{
|
|
struct i2c_client *client = i2c_verify_client(dev);
|
|
struct i2c_driver *driver;
|
|
|
|
if (!client)
|
|
return 0;
|
|
|
|
/* Attempt an OF style match */
|
|
if (of_driver_match_device(dev, drv))
|
|
return 1;
|
|
|
|
/* Then ACPI style match */
|
|
if (acpi_driver_match_device(dev, drv))
|
|
return 1;
|
|
|
|
driver = to_i2c_driver(drv);
|
|
/* match on an id table if there is one */
|
|
if (driver->id_table)
|
|
return i2c_match_id(driver->id_table, client) != NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
int rc;
|
|
|
|
rc = acpi_device_uevent_modalias(dev, env);
|
|
if (rc != -ENODEV)
|
|
return rc;
|
|
|
|
return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name);
|
|
}
|
|
|
|
/* i2c bus recovery routines */
|
|
static int get_scl_gpio_value(struct i2c_adapter *adap)
|
|
{
|
|
return gpio_get_value(adap->bus_recovery_info->scl_gpio);
|
|
}
|
|
|
|
static void set_scl_gpio_value(struct i2c_adapter *adap, int val)
|
|
{
|
|
gpio_set_value(adap->bus_recovery_info->scl_gpio, val);
|
|
}
|
|
|
|
static int get_sda_gpio_value(struct i2c_adapter *adap)
|
|
{
|
|
return gpio_get_value(adap->bus_recovery_info->sda_gpio);
|
|
}
|
|
|
|
static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap)
|
|
{
|
|
struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
|
|
struct device *dev = &adap->dev;
|
|
int ret = 0;
|
|
|
|
ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN |
|
|
GPIOF_OUT_INIT_HIGH, "i2c-scl");
|
|
if (ret) {
|
|
dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio);
|
|
return ret;
|
|
}
|
|
|
|
if (bri->get_sda) {
|
|
if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) {
|
|
/* work without SDA polling */
|
|
dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n",
|
|
bri->sda_gpio);
|
|
bri->get_sda = NULL;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap)
|
|
{
|
|
struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
|
|
|
|
if (bri->get_sda)
|
|
gpio_free(bri->sda_gpio);
|
|
|
|
gpio_free(bri->scl_gpio);
|
|
}
|
|
|
|
/*
|
|
* We are generating clock pulses. ndelay() determines durating of clk pulses.
|
|
* We will generate clock with rate 100 KHz and so duration of both clock levels
|
|
* is: delay in ns = (10^6 / 100) / 2
|
|
*/
|
|
#define RECOVERY_NDELAY 5000
|
|
#define RECOVERY_CLK_CNT 9
|
|
|
|
static int i2c_generic_recovery(struct i2c_adapter *adap)
|
|
{
|
|
struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
|
|
int i = 0, val = 1, ret = 0;
|
|
|
|
if (bri->prepare_recovery)
|
|
bri->prepare_recovery(adap);
|
|
|
|
bri->set_scl(adap, val);
|
|
ndelay(RECOVERY_NDELAY);
|
|
|
|
/*
|
|
* By this time SCL is high, as we need to give 9 falling-rising edges
|
|
*/
|
|
while (i++ < RECOVERY_CLK_CNT * 2) {
|
|
if (val) {
|
|
/* Break if SDA is high */
|
|
if (bri->get_sda && bri->get_sda(adap))
|
|
break;
|
|
/* SCL shouldn't be low here */
|
|
if (!bri->get_scl(adap)) {
|
|
dev_err(&adap->dev,
|
|
"SCL is stuck low, exit recovery\n");
|
|
ret = -EBUSY;
|
|
break;
|
|
}
|
|
}
|
|
|
|
val = !val;
|
|
bri->set_scl(adap, val);
|
|
ndelay(RECOVERY_NDELAY);
|
|
}
|
|
|
|
if (bri->unprepare_recovery)
|
|
bri->unprepare_recovery(adap);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int i2c_generic_scl_recovery(struct i2c_adapter *adap)
|
|
{
|
|
return i2c_generic_recovery(adap);
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery);
|
|
|
|
int i2c_generic_gpio_recovery(struct i2c_adapter *adap)
|
|
{
|
|
int ret;
|
|
|
|
ret = i2c_get_gpios_for_recovery(adap);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = i2c_generic_recovery(adap);
|
|
i2c_put_gpios_for_recovery(adap);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_generic_gpio_recovery);
|
|
|
|
int i2c_recover_bus(struct i2c_adapter *adap)
|
|
{
|
|
if (!adap->bus_recovery_info)
|
|
return -EOPNOTSUPP;
|
|
|
|
dev_dbg(&adap->dev, "Trying i2c bus recovery\n");
|
|
return adap->bus_recovery_info->recover_bus(adap);
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_recover_bus);
|
|
|
|
static void i2c_init_recovery(struct i2c_adapter *adap)
|
|
{
|
|
struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
|
|
char *err_str;
|
|
|
|
if (!bri)
|
|
return;
|
|
|
|
if (!bri->recover_bus) {
|
|
err_str = "no recover_bus() found";
|
|
goto err;
|
|
}
|
|
|
|
/* Generic GPIO recovery */
|
|
if (bri->recover_bus == i2c_generic_gpio_recovery) {
|
|
if (!gpio_is_valid(bri->scl_gpio)) {
|
|
err_str = "invalid SCL gpio";
|
|
goto err;
|
|
}
|
|
|
|
if (gpio_is_valid(bri->sda_gpio))
|
|
bri->get_sda = get_sda_gpio_value;
|
|
else
|
|
bri->get_sda = NULL;
|
|
|
|
bri->get_scl = get_scl_gpio_value;
|
|
bri->set_scl = set_scl_gpio_value;
|
|
} else if (bri->recover_bus == i2c_generic_scl_recovery) {
|
|
/* Generic SCL recovery */
|
|
if (!bri->set_scl || !bri->get_scl) {
|
|
err_str = "no {get|set}_scl() found";
|
|
goto err;
|
|
}
|
|
}
|
|
|
|
return;
|
|
err:
|
|
dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
|
|
adap->bus_recovery_info = NULL;
|
|
}
|
|
|
|
static int i2c_device_probe(struct device *dev)
|
|
{
|
|
struct i2c_client *client = i2c_verify_client(dev);
|
|
struct i2c_driver *driver;
|
|
int status;
|
|
|
|
if (!client)
|
|
return 0;
|
|
|
|
if (!client->irq) {
|
|
int irq = -ENOENT;
|
|
|
|
if (dev->of_node) {
|
|
irq = of_irq_get_byname(dev->of_node, "irq");
|
|
if (irq == -EINVAL || irq == -ENODATA)
|
|
irq = of_irq_get(dev->of_node, 0);
|
|
} else if (ACPI_COMPANION(dev)) {
|
|
irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0);
|
|
}
|
|
if (irq == -EPROBE_DEFER)
|
|
return irq;
|
|
if (irq < 0)
|
|
irq = 0;
|
|
|
|
client->irq = irq;
|
|
}
|
|
|
|
driver = to_i2c_driver(dev->driver);
|
|
if (!driver->probe || !driver->id_table)
|
|
return -ENODEV;
|
|
|
|
if (client->flags & I2C_CLIENT_WAKE) {
|
|
int wakeirq = -ENOENT;
|
|
|
|
if (dev->of_node) {
|
|
wakeirq = of_irq_get_byname(dev->of_node, "wakeup");
|
|
if (wakeirq == -EPROBE_DEFER)
|
|
return wakeirq;
|
|
}
|
|
|
|
device_init_wakeup(&client->dev, true);
|
|
|
|
if (wakeirq > 0 && wakeirq != client->irq)
|
|
status = dev_pm_set_dedicated_wake_irq(dev, wakeirq);
|
|
else if (client->irq > 0)
|
|
status = dev_pm_set_wake_irq(dev, client->irq);
|
|
else
|
|
status = 0;
|
|
|
|
if (status)
|
|
dev_warn(&client->dev, "failed to set up wakeup irq");
|
|
}
|
|
|
|
dev_dbg(dev, "probe\n");
|
|
|
|
status = of_clk_set_defaults(dev->of_node, false);
|
|
if (status < 0)
|
|
goto err_clear_wakeup_irq;
|
|
|
|
status = dev_pm_domain_attach(&client->dev, true);
|
|
if (status == -EPROBE_DEFER)
|
|
goto err_clear_wakeup_irq;
|
|
|
|
status = driver->probe(client, i2c_match_id(driver->id_table, client));
|
|
if (status)
|
|
goto err_detach_pm_domain;
|
|
|
|
return 0;
|
|
|
|
err_detach_pm_domain:
|
|
dev_pm_domain_detach(&client->dev, true);
|
|
err_clear_wakeup_irq:
|
|
dev_pm_clear_wake_irq(&client->dev);
|
|
device_init_wakeup(&client->dev, false);
|
|
return status;
|
|
}
|
|
|
|
static int i2c_device_remove(struct device *dev)
|
|
{
|
|
struct i2c_client *client = i2c_verify_client(dev);
|
|
struct i2c_driver *driver;
|
|
int status = 0;
|
|
|
|
if (!client || !dev->driver)
|
|
return 0;
|
|
|
|
driver = to_i2c_driver(dev->driver);
|
|
if (driver->remove) {
|
|
dev_dbg(dev, "remove\n");
|
|
status = driver->remove(client);
|
|
}
|
|
|
|
dev_pm_domain_detach(&client->dev, true);
|
|
|
|
dev_pm_clear_wake_irq(&client->dev);
|
|
device_init_wakeup(&client->dev, false);
|
|
|
|
return status;
|
|
}
|
|
|
|
static void i2c_device_shutdown(struct device *dev)
|
|
{
|
|
struct i2c_client *client = i2c_verify_client(dev);
|
|
struct i2c_driver *driver;
|
|
|
|
if (!client || !dev->driver)
|
|
return;
|
|
driver = to_i2c_driver(dev->driver);
|
|
if (driver->shutdown)
|
|
driver->shutdown(client);
|
|
}
|
|
|
|
static void i2c_client_dev_release(struct device *dev)
|
|
{
|
|
kfree(to_i2c_client(dev));
|
|
}
|
|
|
|
static ssize_t
|
|
show_name(struct device *dev, struct device_attribute *attr, char *buf)
|
|
{
|
|
return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
|
|
to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
|
|
}
|
|
static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
|
|
|
|
static ssize_t
|
|
show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
int len;
|
|
|
|
len = acpi_device_modalias(dev, buf, PAGE_SIZE -1);
|
|
if (len != -ENODEV)
|
|
return len;
|
|
|
|
return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
|
|
}
|
|
static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
|
|
|
|
static struct attribute *i2c_dev_attrs[] = {
|
|
&dev_attr_name.attr,
|
|
/* modalias helps coldplug: modprobe $(cat .../modalias) */
|
|
&dev_attr_modalias.attr,
|
|
NULL
|
|
};
|
|
ATTRIBUTE_GROUPS(i2c_dev);
|
|
|
|
struct bus_type i2c_bus_type = {
|
|
.name = "i2c",
|
|
.match = i2c_device_match,
|
|
.probe = i2c_device_probe,
|
|
.remove = i2c_device_remove,
|
|
.shutdown = i2c_device_shutdown,
|
|
};
|
|
EXPORT_SYMBOL_GPL(i2c_bus_type);
|
|
|
|
static struct device_type i2c_client_type = {
|
|
.groups = i2c_dev_groups,
|
|
.uevent = i2c_device_uevent,
|
|
.release = i2c_client_dev_release,
|
|
};
|
|
|
|
|
|
/**
|
|
* i2c_verify_client - return parameter as i2c_client, or NULL
|
|
* @dev: device, probably from some driver model iterator
|
|
*
|
|
* When traversing the driver model tree, perhaps using driver model
|
|
* iterators like @device_for_each_child(), you can't assume very much
|
|
* about the nodes you find. Use this function to avoid oopses caused
|
|
* by wrongly treating some non-I2C device as an i2c_client.
|
|
*/
|
|
struct i2c_client *i2c_verify_client(struct device *dev)
|
|
{
|
|
return (dev->type == &i2c_client_type)
|
|
? to_i2c_client(dev)
|
|
: NULL;
|
|
}
|
|
EXPORT_SYMBOL(i2c_verify_client);
|
|
|
|
|
|
/* Return a unique address which takes the flags of the client into account */
|
|
static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client)
|
|
{
|
|
unsigned short addr = client->addr;
|
|
|
|
/* For some client flags, add an arbitrary offset to avoid collisions */
|
|
if (client->flags & I2C_CLIENT_TEN)
|
|
addr |= I2C_ADDR_OFFSET_TEN_BIT;
|
|
|
|
if (client->flags & I2C_CLIENT_SLAVE)
|
|
addr |= I2C_ADDR_OFFSET_SLAVE;
|
|
|
|
return addr;
|
|
}
|
|
|
|
/* This is a permissive address validity check, I2C address map constraints
|
|
* are purposely not enforced, except for the general call address. */
|
|
static int i2c_check_addr_validity(unsigned addr, unsigned short flags)
|
|
{
|
|
if (flags & I2C_CLIENT_TEN) {
|
|
/* 10-bit address, all values are valid */
|
|
if (addr > 0x3ff)
|
|
return -EINVAL;
|
|
} else {
|
|
/* 7-bit address, reject the general call address */
|
|
if (addr == 0x00 || addr > 0x7f)
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* And this is a strict address validity check, used when probing. If a
|
|
* device uses a reserved address, then it shouldn't be probed. 7-bit
|
|
* addressing is assumed, 10-bit address devices are rare and should be
|
|
* explicitly enumerated. */
|
|
static int i2c_check_7bit_addr_validity_strict(unsigned short addr)
|
|
{
|
|
/*
|
|
* Reserved addresses per I2C specification:
|
|
* 0x00 General call address / START byte
|
|
* 0x01 CBUS address
|
|
* 0x02 Reserved for different bus format
|
|
* 0x03 Reserved for future purposes
|
|
* 0x04-0x07 Hs-mode master code
|
|
* 0x78-0x7b 10-bit slave addressing
|
|
* 0x7c-0x7f Reserved for future purposes
|
|
*/
|
|
if (addr < 0x08 || addr > 0x77)
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static int __i2c_check_addr_busy(struct device *dev, void *addrp)
|
|
{
|
|
struct i2c_client *client = i2c_verify_client(dev);
|
|
int addr = *(int *)addrp;
|
|
|
|
if (client && i2c_encode_flags_to_addr(client) == addr)
|
|
return -EBUSY;
|
|
return 0;
|
|
}
|
|
|
|
/* walk up mux tree */
|
|
static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
|
|
{
|
|
struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
|
|
int result;
|
|
|
|
result = device_for_each_child(&adapter->dev, &addr,
|
|
__i2c_check_addr_busy);
|
|
|
|
if (!result && parent)
|
|
result = i2c_check_mux_parents(parent, addr);
|
|
|
|
return result;
|
|
}
|
|
|
|
/* recurse down mux tree */
|
|
static int i2c_check_mux_children(struct device *dev, void *addrp)
|
|
{
|
|
int result;
|
|
|
|
if (dev->type == &i2c_adapter_type)
|
|
result = device_for_each_child(dev, addrp,
|
|
i2c_check_mux_children);
|
|
else
|
|
result = __i2c_check_addr_busy(dev, addrp);
|
|
|
|
return result;
|
|
}
|
|
|
|
static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
|
|
{
|
|
struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
|
|
int result = 0;
|
|
|
|
if (parent)
|
|
result = i2c_check_mux_parents(parent, addr);
|
|
|
|
if (!result)
|
|
result = device_for_each_child(&adapter->dev, &addr,
|
|
i2c_check_mux_children);
|
|
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment
|
|
* @adapter: Target I2C bus segment
|
|
* @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
|
|
* locks only this branch in the adapter tree
|
|
*/
|
|
static void i2c_adapter_lock_bus(struct i2c_adapter *adapter,
|
|
unsigned int flags)
|
|
{
|
|
rt_mutex_lock(&adapter->bus_lock);
|
|
}
|
|
|
|
/**
|
|
* i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment
|
|
* @adapter: Target I2C bus segment
|
|
* @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT
|
|
* trylocks only this branch in the adapter tree
|
|
*/
|
|
static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter,
|
|
unsigned int flags)
|
|
{
|
|
return rt_mutex_trylock(&adapter->bus_lock);
|
|
}
|
|
|
|
/**
|
|
* i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment
|
|
* @adapter: Target I2C bus segment
|
|
* @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
|
|
* unlocks only this branch in the adapter tree
|
|
*/
|
|
static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter,
|
|
unsigned int flags)
|
|
{
|
|
rt_mutex_unlock(&adapter->bus_lock);
|
|
}
|
|
|
|
static void i2c_dev_set_name(struct i2c_adapter *adap,
|
|
struct i2c_client *client)
|
|
{
|
|
struct acpi_device *adev = ACPI_COMPANION(&client->dev);
|
|
|
|
if (adev) {
|
|
dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev));
|
|
return;
|
|
}
|
|
|
|
dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
|
|
i2c_encode_flags_to_addr(client));
|
|
}
|
|
|
|
/**
|
|
* i2c_new_device - instantiate an i2c device
|
|
* @adap: the adapter managing the device
|
|
* @info: describes one I2C device; bus_num is ignored
|
|
* Context: can sleep
|
|
*
|
|
* Create an i2c device. Binding is handled through driver model
|
|
* probe()/remove() methods. A driver may be bound to this device when we
|
|
* return from this function, or any later moment (e.g. maybe hotplugging will
|
|
* load the driver module). This call is not appropriate for use by mainboard
|
|
* initialization logic, which usually runs during an arch_initcall() long
|
|
* before any i2c_adapter could exist.
|
|
*
|
|
* This returns the new i2c client, which may be saved for later use with
|
|
* i2c_unregister_device(); or NULL to indicate an error.
|
|
*/
|
|
struct i2c_client *
|
|
i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
|
|
{
|
|
struct i2c_client *client;
|
|
int status;
|
|
|
|
client = kzalloc(sizeof *client, GFP_KERNEL);
|
|
if (!client)
|
|
return NULL;
|
|
|
|
client->adapter = adap;
|
|
|
|
client->dev.platform_data = info->platform_data;
|
|
|
|
if (info->archdata)
|
|
client->dev.archdata = *info->archdata;
|
|
|
|
client->flags = info->flags;
|
|
client->addr = info->addr;
|
|
client->irq = info->irq;
|
|
|
|
strlcpy(client->name, info->type, sizeof(client->name));
|
|
|
|
status = i2c_check_addr_validity(client->addr, client->flags);
|
|
if (status) {
|
|
dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n",
|
|
client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr);
|
|
goto out_err_silent;
|
|
}
|
|
|
|
/* Check for address business */
|
|
status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
|
|
if (status)
|
|
goto out_err;
|
|
|
|
client->dev.parent = &client->adapter->dev;
|
|
client->dev.bus = &i2c_bus_type;
|
|
client->dev.type = &i2c_client_type;
|
|
client->dev.of_node = info->of_node;
|
|
client->dev.fwnode = info->fwnode;
|
|
|
|
i2c_dev_set_name(adap, client);
|
|
status = device_register(&client->dev);
|
|
if (status)
|
|
goto out_err;
|
|
|
|
dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
|
|
client->name, dev_name(&client->dev));
|
|
|
|
return client;
|
|
|
|
out_err:
|
|
dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x "
|
|
"(%d)\n", client->name, client->addr, status);
|
|
out_err_silent:
|
|
kfree(client);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_new_device);
|
|
|
|
|
|
/**
|
|
* i2c_unregister_device - reverse effect of i2c_new_device()
|
|
* @client: value returned from i2c_new_device()
|
|
* Context: can sleep
|
|
*/
|
|
void i2c_unregister_device(struct i2c_client *client)
|
|
{
|
|
if (client->dev.of_node)
|
|
of_node_clear_flag(client->dev.of_node, OF_POPULATED);
|
|
if (ACPI_COMPANION(&client->dev))
|
|
acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
|
|
device_unregister(&client->dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_unregister_device);
|
|
|
|
|
|
static const struct i2c_device_id dummy_id[] = {
|
|
{ "dummy", 0 },
|
|
{ },
|
|
};
|
|
|
|
static int dummy_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int dummy_remove(struct i2c_client *client)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static struct i2c_driver dummy_driver = {
|
|
.driver.name = "dummy",
|
|
.probe = dummy_probe,
|
|
.remove = dummy_remove,
|
|
.id_table = dummy_id,
|
|
};
|
|
|
|
/**
|
|
* i2c_new_dummy - return a new i2c device bound to a dummy driver
|
|
* @adapter: the adapter managing the device
|
|
* @address: seven bit address to be used
|
|
* Context: can sleep
|
|
*
|
|
* This returns an I2C client bound to the "dummy" driver, intended for use
|
|
* with devices that consume multiple addresses. Examples of such chips
|
|
* include various EEPROMS (like 24c04 and 24c08 models).
|
|
*
|
|
* These dummy devices have two main uses. First, most I2C and SMBus calls
|
|
* except i2c_transfer() need a client handle; the dummy will be that handle.
|
|
* And second, this prevents the specified address from being bound to a
|
|
* different driver.
|
|
*
|
|
* This returns the new i2c client, which should be saved for later use with
|
|
* i2c_unregister_device(); or NULL to indicate an error.
|
|
*/
|
|
struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
|
|
{
|
|
struct i2c_board_info info = {
|
|
I2C_BOARD_INFO("dummy", address),
|
|
};
|
|
|
|
return i2c_new_device(adapter, &info);
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_new_dummy);
|
|
|
|
/**
|
|
* i2c_new_secondary_device - Helper to get the instantiated secondary address
|
|
* and create the associated device
|
|
* @client: Handle to the primary client
|
|
* @name: Handle to specify which secondary address to get
|
|
* @default_addr: Used as a fallback if no secondary address was specified
|
|
* Context: can sleep
|
|
*
|
|
* I2C clients can be composed of multiple I2C slaves bound together in a single
|
|
* component. The I2C client driver then binds to the master I2C slave and needs
|
|
* to create I2C dummy clients to communicate with all the other slaves.
|
|
*
|
|
* This function creates and returns an I2C dummy client whose I2C address is
|
|
* retrieved from the platform firmware based on the given slave name. If no
|
|
* address is specified by the firmware default_addr is used.
|
|
*
|
|
* On DT-based platforms the address is retrieved from the "reg" property entry
|
|
* cell whose "reg-names" value matches the slave name.
|
|
*
|
|
* This returns the new i2c client, which should be saved for later use with
|
|
* i2c_unregister_device(); or NULL to indicate an error.
|
|
*/
|
|
struct i2c_client *i2c_new_secondary_device(struct i2c_client *client,
|
|
const char *name,
|
|
u16 default_addr)
|
|
{
|
|
struct device_node *np = client->dev.of_node;
|
|
u32 addr = default_addr;
|
|
int i;
|
|
|
|
if (np) {
|
|
i = of_property_match_string(np, "reg-names", name);
|
|
if (i >= 0)
|
|
of_property_read_u32_index(np, "reg", i, &addr);
|
|
}
|
|
|
|
dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
|
|
return i2c_new_dummy(client->adapter, addr);
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_new_secondary_device);
|
|
|
|
/* ------------------------------------------------------------------------- */
|
|
|
|
/* I2C bus adapters -- one roots each I2C or SMBUS segment */
|
|
|
|
static void i2c_adapter_dev_release(struct device *dev)
|
|
{
|
|
struct i2c_adapter *adap = to_i2c_adapter(dev);
|
|
complete(&adap->dev_released);
|
|
}
|
|
|
|
/*
|
|
* This function is only needed for mutex_lock_nested, so it is never
|
|
* called unless locking correctness checking is enabled. Thus we
|
|
* make it inline to avoid a compiler warning. That's what gcc ends up
|
|
* doing anyway.
|
|
*/
|
|
static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
|
|
{
|
|
unsigned int depth = 0;
|
|
|
|
while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
|
|
depth++;
|
|
|
|
return depth;
|
|
}
|
|
|
|
/*
|
|
* Let users instantiate I2C devices through sysfs. This can be used when
|
|
* platform initialization code doesn't contain the proper data for
|
|
* whatever reason. Also useful for drivers that do device detection and
|
|
* detection fails, either because the device uses an unexpected address,
|
|
* or this is a compatible device with different ID register values.
|
|
*
|
|
* Parameter checking may look overzealous, but we really don't want
|
|
* the user to provide incorrect parameters.
|
|
*/
|
|
static ssize_t
|
|
i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct i2c_adapter *adap = to_i2c_adapter(dev);
|
|
struct i2c_board_info info;
|
|
struct i2c_client *client;
|
|
char *blank, end;
|
|
int res;
|
|
|
|
memset(&info, 0, sizeof(struct i2c_board_info));
|
|
|
|
blank = strchr(buf, ' ');
|
|
if (!blank) {
|
|
dev_err(dev, "%s: Missing parameters\n", "new_device");
|
|
return -EINVAL;
|
|
}
|
|
if (blank - buf > I2C_NAME_SIZE - 1) {
|
|
dev_err(dev, "%s: Invalid device name\n", "new_device");
|
|
return -EINVAL;
|
|
}
|
|
memcpy(info.type, buf, blank - buf);
|
|
|
|
/* Parse remaining parameters, reject extra parameters */
|
|
res = sscanf(++blank, "%hi%c", &info.addr, &end);
|
|
if (res < 1) {
|
|
dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
|
|
return -EINVAL;
|
|
}
|
|
if (res > 1 && end != '\n') {
|
|
dev_err(dev, "%s: Extra parameters\n", "new_device");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) {
|
|
info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT;
|
|
info.flags |= I2C_CLIENT_TEN;
|
|
}
|
|
|
|
if (info.addr & I2C_ADDR_OFFSET_SLAVE) {
|
|
info.addr &= ~I2C_ADDR_OFFSET_SLAVE;
|
|
info.flags |= I2C_CLIENT_SLAVE;
|
|
}
|
|
|
|
client = i2c_new_device(adap, &info);
|
|
if (!client)
|
|
return -EINVAL;
|
|
|
|
/* Keep track of the added device */
|
|
mutex_lock(&adap->userspace_clients_lock);
|
|
list_add_tail(&client->detected, &adap->userspace_clients);
|
|
mutex_unlock(&adap->userspace_clients_lock);
|
|
dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
|
|
info.type, info.addr);
|
|
|
|
return count;
|
|
}
|
|
static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device);
|
|
|
|
/*
|
|
* And of course let the users delete the devices they instantiated, if
|
|
* they got it wrong. This interface can only be used to delete devices
|
|
* instantiated by i2c_sysfs_new_device above. This guarantees that we
|
|
* don't delete devices to which some kernel code still has references.
|
|
*
|
|
* Parameter checking may look overzealous, but we really don't want
|
|
* the user to delete the wrong device.
|
|
*/
|
|
static ssize_t
|
|
i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct i2c_adapter *adap = to_i2c_adapter(dev);
|
|
struct i2c_client *client, *next;
|
|
unsigned short addr;
|
|
char end;
|
|
int res;
|
|
|
|
/* Parse parameters, reject extra parameters */
|
|
res = sscanf(buf, "%hi%c", &addr, &end);
|
|
if (res < 1) {
|
|
dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
|
|
return -EINVAL;
|
|
}
|
|
if (res > 1 && end != '\n') {
|
|
dev_err(dev, "%s: Extra parameters\n", "delete_device");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Make sure the device was added through sysfs */
|
|
res = -ENOENT;
|
|
mutex_lock_nested(&adap->userspace_clients_lock,
|
|
i2c_adapter_depth(adap));
|
|
list_for_each_entry_safe(client, next, &adap->userspace_clients,
|
|
detected) {
|
|
if (i2c_encode_flags_to_addr(client) == addr) {
|
|
dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
|
|
"delete_device", client->name, client->addr);
|
|
|
|
list_del(&client->detected);
|
|
i2c_unregister_device(client);
|
|
res = count;
|
|
break;
|
|
}
|
|
}
|
|
mutex_unlock(&adap->userspace_clients_lock);
|
|
|
|
if (res < 0)
|
|
dev_err(dev, "%s: Can't find device in list\n",
|
|
"delete_device");
|
|
return res;
|
|
}
|
|
static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,
|
|
i2c_sysfs_delete_device);
|
|
|
|
static struct attribute *i2c_adapter_attrs[] = {
|
|
&dev_attr_name.attr,
|
|
&dev_attr_new_device.attr,
|
|
&dev_attr_delete_device.attr,
|
|
NULL
|
|
};
|
|
ATTRIBUTE_GROUPS(i2c_adapter);
|
|
|
|
struct device_type i2c_adapter_type = {
|
|
.groups = i2c_adapter_groups,
|
|
.release = i2c_adapter_dev_release,
|
|
};
|
|
EXPORT_SYMBOL_GPL(i2c_adapter_type);
|
|
|
|
/**
|
|
* i2c_verify_adapter - return parameter as i2c_adapter or NULL
|
|
* @dev: device, probably from some driver model iterator
|
|
*
|
|
* When traversing the driver model tree, perhaps using driver model
|
|
* iterators like @device_for_each_child(), you can't assume very much
|
|
* about the nodes you find. Use this function to avoid oopses caused
|
|
* by wrongly treating some non-I2C device as an i2c_adapter.
|
|
*/
|
|
struct i2c_adapter *i2c_verify_adapter(struct device *dev)
|
|
{
|
|
return (dev->type == &i2c_adapter_type)
|
|
? to_i2c_adapter(dev)
|
|
: NULL;
|
|
}
|
|
EXPORT_SYMBOL(i2c_verify_adapter);
|
|
|
|
#ifdef CONFIG_I2C_COMPAT
|
|
static struct class_compat *i2c_adapter_compat_class;
|
|
#endif
|
|
|
|
static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
|
|
{
|
|
struct i2c_devinfo *devinfo;
|
|
|
|
down_read(&__i2c_board_lock);
|
|
list_for_each_entry(devinfo, &__i2c_board_list, list) {
|
|
if (devinfo->busnum == adapter->nr
|
|
&& !i2c_new_device(adapter,
|
|
&devinfo->board_info))
|
|
dev_err(&adapter->dev,
|
|
"Can't create device at 0x%02x\n",
|
|
devinfo->board_info.addr);
|
|
}
|
|
up_read(&__i2c_board_lock);
|
|
}
|
|
|
|
/* OF support code */
|
|
|
|
#if IS_ENABLED(CONFIG_OF)
|
|
static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
|
|
struct device_node *node)
|
|
{
|
|
struct i2c_client *result;
|
|
struct i2c_board_info info = {};
|
|
struct dev_archdata dev_ad = {};
|
|
const __be32 *addr_be;
|
|
u32 addr;
|
|
int len;
|
|
|
|
dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name);
|
|
|
|
if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
|
|
dev_err(&adap->dev, "of_i2c: modalias failure on %s\n",
|
|
node->full_name);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
addr_be = of_get_property(node, "reg", &len);
|
|
if (!addr_be || (len < sizeof(*addr_be))) {
|
|
dev_err(&adap->dev, "of_i2c: invalid reg on %s\n",
|
|
node->full_name);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
addr = be32_to_cpup(addr_be);
|
|
if (addr & I2C_TEN_BIT_ADDRESS) {
|
|
addr &= ~I2C_TEN_BIT_ADDRESS;
|
|
info.flags |= I2C_CLIENT_TEN;
|
|
}
|
|
|
|
if (addr & I2C_OWN_SLAVE_ADDRESS) {
|
|
addr &= ~I2C_OWN_SLAVE_ADDRESS;
|
|
info.flags |= I2C_CLIENT_SLAVE;
|
|
}
|
|
|
|
if (i2c_check_addr_validity(addr, info.flags)) {
|
|
dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n",
|
|
info.addr, node->full_name);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
info.addr = addr;
|
|
info.of_node = of_node_get(node);
|
|
info.archdata = &dev_ad;
|
|
|
|
if (of_get_property(node, "wakeup-source", NULL))
|
|
info.flags |= I2C_CLIENT_WAKE;
|
|
|
|
result = i2c_new_device(adap, &info);
|
|
if (result == NULL) {
|
|
dev_err(&adap->dev, "of_i2c: Failure registering %s\n",
|
|
node->full_name);
|
|
of_node_put(node);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
static void of_i2c_register_devices(struct i2c_adapter *adap)
|
|
{
|
|
struct device_node *node;
|
|
|
|
/* Only register child devices if the adapter has a node pointer set */
|
|
if (!adap->dev.of_node)
|
|
return;
|
|
|
|
dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
|
|
|
|
for_each_available_child_of_node(adap->dev.of_node, node) {
|
|
if (of_node_test_and_set_flag(node, OF_POPULATED))
|
|
continue;
|
|
of_i2c_register_device(adap, node);
|
|
}
|
|
}
|
|
|
|
static int of_dev_node_match(struct device *dev, void *data)
|
|
{
|
|
return dev->of_node == data;
|
|
}
|
|
|
|
/* must call put_device() when done with returned i2c_client device */
|
|
struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
|
|
{
|
|
struct device *dev;
|
|
struct i2c_client *client;
|
|
|
|
dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
|
|
if (!dev)
|
|
return NULL;
|
|
|
|
client = i2c_verify_client(dev);
|
|
if (!client)
|
|
put_device(dev);
|
|
|
|
return client;
|
|
}
|
|
EXPORT_SYMBOL(of_find_i2c_device_by_node);
|
|
|
|
/* must call put_device() when done with returned i2c_adapter device */
|
|
struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
|
|
{
|
|
struct device *dev;
|
|
struct i2c_adapter *adapter;
|
|
|
|
dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
|
|
if (!dev)
|
|
return NULL;
|
|
|
|
adapter = i2c_verify_adapter(dev);
|
|
if (!adapter)
|
|
put_device(dev);
|
|
|
|
return adapter;
|
|
}
|
|
EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
|
|
|
|
/* must call i2c_put_adapter() when done with returned i2c_adapter device */
|
|
struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
|
|
{
|
|
struct i2c_adapter *adapter;
|
|
|
|
adapter = of_find_i2c_adapter_by_node(node);
|
|
if (!adapter)
|
|
return NULL;
|
|
|
|
if (!try_module_get(adapter->owner)) {
|
|
put_device(&adapter->dev);
|
|
adapter = NULL;
|
|
}
|
|
|
|
return adapter;
|
|
}
|
|
EXPORT_SYMBOL(of_get_i2c_adapter_by_node);
|
|
#else
|
|
static void of_i2c_register_devices(struct i2c_adapter *adap) { }
|
|
#endif /* CONFIG_OF */
|
|
|
|
static int i2c_do_add_adapter(struct i2c_driver *driver,
|
|
struct i2c_adapter *adap)
|
|
{
|
|
/* Detect supported devices on that bus, and instantiate them */
|
|
i2c_detect(adap, driver);
|
|
|
|
/* Let legacy drivers scan this bus for matching devices */
|
|
if (driver->attach_adapter) {
|
|
dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n",
|
|
driver->driver.name);
|
|
dev_warn(&adap->dev, "Please use another way to instantiate "
|
|
"your i2c_client\n");
|
|
/* We ignore the return code; if it fails, too bad */
|
|
driver->attach_adapter(adap);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int __process_new_adapter(struct device_driver *d, void *data)
|
|
{
|
|
return i2c_do_add_adapter(to_i2c_driver(d), data);
|
|
}
|
|
|
|
static int i2c_register_adapter(struct i2c_adapter *adap)
|
|
{
|
|
int res = -EINVAL;
|
|
|
|
/* Can't register until after driver model init */
|
|
if (WARN_ON(!is_registered)) {
|
|
res = -EAGAIN;
|
|
goto out_list;
|
|
}
|
|
|
|
/* Sanity checks */
|
|
if (WARN(!adap->name[0], "i2c adapter has no name"))
|
|
goto out_list;
|
|
|
|
if (!adap->algo) {
|
|
pr_err("adapter '%s': no algo supplied!\n", adap->name);
|
|
goto out_list;
|
|
}
|
|
|
|
if (!adap->lock_bus) {
|
|
adap->lock_bus = i2c_adapter_lock_bus;
|
|
adap->trylock_bus = i2c_adapter_trylock_bus;
|
|
adap->unlock_bus = i2c_adapter_unlock_bus;
|
|
}
|
|
|
|
rt_mutex_init(&adap->bus_lock);
|
|
rt_mutex_init(&adap->mux_lock);
|
|
mutex_init(&adap->userspace_clients_lock);
|
|
INIT_LIST_HEAD(&adap->userspace_clients);
|
|
|
|
/* Set default timeout to 1 second if not already set */
|
|
if (adap->timeout == 0)
|
|
adap->timeout = HZ;
|
|
|
|
dev_set_name(&adap->dev, "i2c-%d", adap->nr);
|
|
adap->dev.bus = &i2c_bus_type;
|
|
adap->dev.type = &i2c_adapter_type;
|
|
res = device_register(&adap->dev);
|
|
if (res) {
|
|
pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
|
|
goto out_list;
|
|
}
|
|
|
|
dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
|
|
|
|
pm_runtime_no_callbacks(&adap->dev);
|
|
pm_suspend_ignore_children(&adap->dev, true);
|
|
pm_runtime_enable(&adap->dev);
|
|
|
|
#ifdef CONFIG_I2C_COMPAT
|
|
res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
|
|
adap->dev.parent);
|
|
if (res)
|
|
dev_warn(&adap->dev,
|
|
"Failed to create compatibility class link\n");
|
|
#endif
|
|
|
|
i2c_init_recovery(adap);
|
|
|
|
/* create pre-declared device nodes */
|
|
of_i2c_register_devices(adap);
|
|
acpi_i2c_register_devices(adap);
|
|
acpi_i2c_install_space_handler(adap);
|
|
|
|
if (adap->nr < __i2c_first_dynamic_bus_num)
|
|
i2c_scan_static_board_info(adap);
|
|
|
|
/* Notify drivers */
|
|
mutex_lock(&core_lock);
|
|
bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter);
|
|
mutex_unlock(&core_lock);
|
|
|
|
return 0;
|
|
|
|
out_list:
|
|
mutex_lock(&core_lock);
|
|
idr_remove(&i2c_adapter_idr, adap->nr);
|
|
mutex_unlock(&core_lock);
|
|
return res;
|
|
}
|
|
|
|
/**
|
|
* __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1
|
|
* @adap: the adapter to register (with adap->nr initialized)
|
|
* Context: can sleep
|
|
*
|
|
* See i2c_add_numbered_adapter() for details.
|
|
*/
|
|
static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
|
|
{
|
|
int id;
|
|
|
|
mutex_lock(&core_lock);
|
|
id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
|
|
mutex_unlock(&core_lock);
|
|
if (WARN(id < 0, "couldn't get idr"))
|
|
return id == -ENOSPC ? -EBUSY : id;
|
|
|
|
return i2c_register_adapter(adap);
|
|
}
|
|
|
|
/**
|
|
* i2c_add_adapter - declare i2c adapter, use dynamic bus number
|
|
* @adapter: the adapter to add
|
|
* Context: can sleep
|
|
*
|
|
* This routine is used to declare an I2C adapter when its bus number
|
|
* doesn't matter or when its bus number is specified by an dt alias.
|
|
* Examples of bases when the bus number doesn't matter: I2C adapters
|
|
* dynamically added by USB links or PCI plugin cards.
|
|
*
|
|
* When this returns zero, a new bus number was allocated and stored
|
|
* in adap->nr, and the specified adapter became available for clients.
|
|
* Otherwise, a negative errno value is returned.
|
|
*/
|
|
int i2c_add_adapter(struct i2c_adapter *adapter)
|
|
{
|
|
struct device *dev = &adapter->dev;
|
|
int id;
|
|
|
|
if (dev->of_node) {
|
|
id = of_alias_get_id(dev->of_node, "i2c");
|
|
if (id >= 0) {
|
|
adapter->nr = id;
|
|
return __i2c_add_numbered_adapter(adapter);
|
|
}
|
|
}
|
|
|
|
mutex_lock(&core_lock);
|
|
id = idr_alloc(&i2c_adapter_idr, adapter,
|
|
__i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
|
|
mutex_unlock(&core_lock);
|
|
if (WARN(id < 0, "couldn't get idr"))
|
|
return id;
|
|
|
|
adapter->nr = id;
|
|
|
|
return i2c_register_adapter(adapter);
|
|
}
|
|
EXPORT_SYMBOL(i2c_add_adapter);
|
|
|
|
/**
|
|
* i2c_add_numbered_adapter - declare i2c adapter, use static bus number
|
|
* @adap: the adapter to register (with adap->nr initialized)
|
|
* Context: can sleep
|
|
*
|
|
* This routine is used to declare an I2C adapter when its bus number
|
|
* matters. For example, use it for I2C adapters from system-on-chip CPUs,
|
|
* or otherwise built in to the system's mainboard, and where i2c_board_info
|
|
* is used to properly configure I2C devices.
|
|
*
|
|
* If the requested bus number is set to -1, then this function will behave
|
|
* identically to i2c_add_adapter, and will dynamically assign a bus number.
|
|
*
|
|
* If no devices have pre-been declared for this bus, then be sure to
|
|
* register the adapter before any dynamically allocated ones. Otherwise
|
|
* the required bus ID may not be available.
|
|
*
|
|
* When this returns zero, the specified adapter became available for
|
|
* clients using the bus number provided in adap->nr. Also, the table
|
|
* of I2C devices pre-declared using i2c_register_board_info() is scanned,
|
|
* and the appropriate driver model device nodes are created. Otherwise, a
|
|
* negative errno value is returned.
|
|
*/
|
|
int i2c_add_numbered_adapter(struct i2c_adapter *adap)
|
|
{
|
|
if (adap->nr == -1) /* -1 means dynamically assign bus id */
|
|
return i2c_add_adapter(adap);
|
|
|
|
return __i2c_add_numbered_adapter(adap);
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
|
|
|
|
static void i2c_do_del_adapter(struct i2c_driver *driver,
|
|
struct i2c_adapter *adapter)
|
|
{
|
|
struct i2c_client *client, *_n;
|
|
|
|
/* Remove the devices we created ourselves as the result of hardware
|
|
* probing (using a driver's detect method) */
|
|
list_for_each_entry_safe(client, _n, &driver->clients, detected) {
|
|
if (client->adapter == adapter) {
|
|
dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
|
|
client->name, client->addr);
|
|
list_del(&client->detected);
|
|
i2c_unregister_device(client);
|
|
}
|
|
}
|
|
}
|
|
|
|
static int __unregister_client(struct device *dev, void *dummy)
|
|
{
|
|
struct i2c_client *client = i2c_verify_client(dev);
|
|
if (client && strcmp(client->name, "dummy"))
|
|
i2c_unregister_device(client);
|
|
return 0;
|
|
}
|
|
|
|
static int __unregister_dummy(struct device *dev, void *dummy)
|
|
{
|
|
struct i2c_client *client = i2c_verify_client(dev);
|
|
if (client)
|
|
i2c_unregister_device(client);
|
|
return 0;
|
|
}
|
|
|
|
static int __process_removed_adapter(struct device_driver *d, void *data)
|
|
{
|
|
i2c_do_del_adapter(to_i2c_driver(d), data);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* i2c_del_adapter - unregister I2C adapter
|
|
* @adap: the adapter being unregistered
|
|
* Context: can sleep
|
|
*
|
|
* This unregisters an I2C adapter which was previously registered
|
|
* by @i2c_add_adapter or @i2c_add_numbered_adapter.
|
|
*/
|
|
void i2c_del_adapter(struct i2c_adapter *adap)
|
|
{
|
|
struct i2c_adapter *found;
|
|
struct i2c_client *client, *next;
|
|
|
|
/* First make sure that this adapter was ever added */
|
|
mutex_lock(&core_lock);
|
|
found = idr_find(&i2c_adapter_idr, adap->nr);
|
|
mutex_unlock(&core_lock);
|
|
if (found != adap) {
|
|
pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
|
|
return;
|
|
}
|
|
|
|
acpi_i2c_remove_space_handler(adap);
|
|
/* Tell drivers about this removal */
|
|
mutex_lock(&core_lock);
|
|
bus_for_each_drv(&i2c_bus_type, NULL, adap,
|
|
__process_removed_adapter);
|
|
mutex_unlock(&core_lock);
|
|
|
|
/* Remove devices instantiated from sysfs */
|
|
mutex_lock_nested(&adap->userspace_clients_lock,
|
|
i2c_adapter_depth(adap));
|
|
list_for_each_entry_safe(client, next, &adap->userspace_clients,
|
|
detected) {
|
|
dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
|
|
client->addr);
|
|
list_del(&client->detected);
|
|
i2c_unregister_device(client);
|
|
}
|
|
mutex_unlock(&adap->userspace_clients_lock);
|
|
|
|
/* Detach any active clients. This can't fail, thus we do not
|
|
* check the returned value. This is a two-pass process, because
|
|
* we can't remove the dummy devices during the first pass: they
|
|
* could have been instantiated by real devices wishing to clean
|
|
* them up properly, so we give them a chance to do that first. */
|
|
device_for_each_child(&adap->dev, NULL, __unregister_client);
|
|
device_for_each_child(&adap->dev, NULL, __unregister_dummy);
|
|
|
|
#ifdef CONFIG_I2C_COMPAT
|
|
class_compat_remove_link(i2c_adapter_compat_class, &adap->dev,
|
|
adap->dev.parent);
|
|
#endif
|
|
|
|
/* device name is gone after device_unregister */
|
|
dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
|
|
|
|
pm_runtime_disable(&adap->dev);
|
|
|
|
/* wait until all references to the device are gone
|
|
*
|
|
* FIXME: This is old code and should ideally be replaced by an
|
|
* alternative which results in decoupling the lifetime of the struct
|
|
* device from the i2c_adapter, like spi or netdev do. Any solution
|
|
* should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled!
|
|
*/
|
|
init_completion(&adap->dev_released);
|
|
device_unregister(&adap->dev);
|
|
wait_for_completion(&adap->dev_released);
|
|
|
|
/* free bus id */
|
|
mutex_lock(&core_lock);
|
|
idr_remove(&i2c_adapter_idr, adap->nr);
|
|
mutex_unlock(&core_lock);
|
|
|
|
/* Clear the device structure in case this adapter is ever going to be
|
|
added again */
|
|
memset(&adap->dev, 0, sizeof(adap->dev));
|
|
}
|
|
EXPORT_SYMBOL(i2c_del_adapter);
|
|
|
|
/**
|
|
* i2c_parse_fw_timings - get I2C related timing parameters from firmware
|
|
* @dev: The device to scan for I2C timing properties
|
|
* @t: the i2c_timings struct to be filled with values
|
|
* @use_defaults: bool to use sane defaults derived from the I2C specification
|
|
* when properties are not found, otherwise use 0
|
|
*
|
|
* Scan the device for the generic I2C properties describing timing parameters
|
|
* for the signal and fill the given struct with the results. If a property was
|
|
* not found and use_defaults was true, then maximum timings are assumed which
|
|
* are derived from the I2C specification. If use_defaults is not used, the
|
|
* results will be 0, so drivers can apply their own defaults later. The latter
|
|
* is mainly intended for avoiding regressions of existing drivers which want
|
|
* to switch to this function. New drivers almost always should use the defaults.
|
|
*/
|
|
|
|
void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults)
|
|
{
|
|
int ret;
|
|
|
|
memset(t, 0, sizeof(*t));
|
|
|
|
ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz);
|
|
if (ret && use_defaults)
|
|
t->bus_freq_hz = 100000;
|
|
|
|
ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns);
|
|
if (ret && use_defaults) {
|
|
if (t->bus_freq_hz <= 100000)
|
|
t->scl_rise_ns = 1000;
|
|
else if (t->bus_freq_hz <= 400000)
|
|
t->scl_rise_ns = 300;
|
|
else
|
|
t->scl_rise_ns = 120;
|
|
}
|
|
|
|
ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns);
|
|
if (ret && use_defaults) {
|
|
if (t->bus_freq_hz <= 400000)
|
|
t->scl_fall_ns = 300;
|
|
else
|
|
t->scl_fall_ns = 120;
|
|
}
|
|
|
|
device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns);
|
|
|
|
ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns);
|
|
if (ret && use_defaults)
|
|
t->sda_fall_ns = t->scl_fall_ns;
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
|
|
|
|
/* ------------------------------------------------------------------------- */
|
|
|
|
int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *))
|
|
{
|
|
int res;
|
|
|
|
mutex_lock(&core_lock);
|
|
res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn);
|
|
mutex_unlock(&core_lock);
|
|
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_for_each_dev);
|
|
|
|
static int __process_new_driver(struct device *dev, void *data)
|
|
{
|
|
if (dev->type != &i2c_adapter_type)
|
|
return 0;
|
|
return i2c_do_add_adapter(data, to_i2c_adapter(dev));
|
|
}
|
|
|
|
/*
|
|
* An i2c_driver is used with one or more i2c_client (device) nodes to access
|
|
* i2c slave chips, on a bus instance associated with some i2c_adapter.
|
|
*/
|
|
|
|
int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
|
|
{
|
|
int res;
|
|
|
|
/* Can't register until after driver model init */
|
|
if (WARN_ON(!is_registered))
|
|
return -EAGAIN;
|
|
|
|
/* add the driver to the list of i2c drivers in the driver core */
|
|
driver->driver.owner = owner;
|
|
driver->driver.bus = &i2c_bus_type;
|
|
|
|
/* When registration returns, the driver core
|
|
* will have called probe() for all matching-but-unbound devices.
|
|
*/
|
|
res = driver_register(&driver->driver);
|
|
if (res)
|
|
return res;
|
|
|
|
pr_debug("driver [%s] registered\n", driver->driver.name);
|
|
|
|
INIT_LIST_HEAD(&driver->clients);
|
|
/* Walk the adapters that are already present */
|
|
i2c_for_each_dev(driver, __process_new_driver);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(i2c_register_driver);
|
|
|
|
static int __process_removed_driver(struct device *dev, void *data)
|
|
{
|
|
if (dev->type == &i2c_adapter_type)
|
|
i2c_do_del_adapter(data, to_i2c_adapter(dev));
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* i2c_del_driver - unregister I2C driver
|
|
* @driver: the driver being unregistered
|
|
* Context: can sleep
|
|
*/
|
|
void i2c_del_driver(struct i2c_driver *driver)
|
|
{
|
|
i2c_for_each_dev(driver, __process_removed_driver);
|
|
|
|
driver_unregister(&driver->driver);
|
|
pr_debug("driver [%s] unregistered\n", driver->driver.name);
|
|
}
|
|
EXPORT_SYMBOL(i2c_del_driver);
|
|
|
|
/* ------------------------------------------------------------------------- */
|
|
|
|
/**
|
|
* i2c_use_client - increments the reference count of the i2c client structure
|
|
* @client: the client being referenced
|
|
*
|
|
* Each live reference to a client should be refcounted. The driver model does
|
|
* that automatically as part of driver binding, so that most drivers don't
|
|
* need to do this explicitly: they hold a reference until they're unbound
|
|
* from the device.
|
|
*
|
|
* A pointer to the client with the incremented reference counter is returned.
|
|
*/
|
|
struct i2c_client *i2c_use_client(struct i2c_client *client)
|
|
{
|
|
if (client && get_device(&client->dev))
|
|
return client;
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(i2c_use_client);
|
|
|
|
/**
|
|
* i2c_release_client - release a use of the i2c client structure
|
|
* @client: the client being no longer referenced
|
|
*
|
|
* Must be called when a user of a client is finished with it.
|
|
*/
|
|
void i2c_release_client(struct i2c_client *client)
|
|
{
|
|
if (client)
|
|
put_device(&client->dev);
|
|
}
|
|
EXPORT_SYMBOL(i2c_release_client);
|
|
|
|
struct i2c_cmd_arg {
|
|
unsigned cmd;
|
|
void *arg;
|
|
};
|
|
|
|
static int i2c_cmd(struct device *dev, void *_arg)
|
|
{
|
|
struct i2c_client *client = i2c_verify_client(dev);
|
|
struct i2c_cmd_arg *arg = _arg;
|
|
struct i2c_driver *driver;
|
|
|
|
if (!client || !client->dev.driver)
|
|
return 0;
|
|
|
|
driver = to_i2c_driver(client->dev.driver);
|
|
if (driver->command)
|
|
driver->command(client, arg->cmd, arg->arg);
|
|
return 0;
|
|
}
|
|
|
|
void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
|
|
{
|
|
struct i2c_cmd_arg cmd_arg;
|
|
|
|
cmd_arg.cmd = cmd;
|
|
cmd_arg.arg = arg;
|
|
device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
|
|
}
|
|
EXPORT_SYMBOL(i2c_clients_command);
|
|
|
|
#if IS_ENABLED(CONFIG_OF_DYNAMIC)
|
|
static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
|
|
void *arg)
|
|
{
|
|
struct of_reconfig_data *rd = arg;
|
|
struct i2c_adapter *adap;
|
|
struct i2c_client *client;
|
|
|
|
switch (of_reconfig_get_state_change(action, rd)) {
|
|
case OF_RECONFIG_CHANGE_ADD:
|
|
adap = of_find_i2c_adapter_by_node(rd->dn->parent);
|
|
if (adap == NULL)
|
|
return NOTIFY_OK; /* not for us */
|
|
|
|
if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
|
|
put_device(&adap->dev);
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
client = of_i2c_register_device(adap, rd->dn);
|
|
put_device(&adap->dev);
|
|
|
|
if (IS_ERR(client)) {
|
|
dev_err(&adap->dev, "failed to create client for '%s'\n",
|
|
rd->dn->full_name);
|
|
return notifier_from_errno(PTR_ERR(client));
|
|
}
|
|
break;
|
|
case OF_RECONFIG_CHANGE_REMOVE:
|
|
/* already depopulated? */
|
|
if (!of_node_check_flag(rd->dn, OF_POPULATED))
|
|
return NOTIFY_OK;
|
|
|
|
/* find our device by node */
|
|
client = of_find_i2c_device_by_node(rd->dn);
|
|
if (client == NULL)
|
|
return NOTIFY_OK; /* no? not meant for us */
|
|
|
|
/* unregister takes one ref away */
|
|
i2c_unregister_device(client);
|
|
|
|
/* and put the reference of the find */
|
|
put_device(&client->dev);
|
|
break;
|
|
}
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
static struct notifier_block i2c_of_notifier = {
|
|
.notifier_call = of_i2c_notify,
|
|
};
|
|
#else
|
|
extern struct notifier_block i2c_of_notifier;
|
|
#endif /* CONFIG_OF_DYNAMIC */
|
|
|
|
static int __init i2c_init(void)
|
|
{
|
|
int retval;
|
|
|
|
retval = of_alias_get_highest_id("i2c");
|
|
|
|
down_write(&__i2c_board_lock);
|
|
if (retval >= __i2c_first_dynamic_bus_num)
|
|
__i2c_first_dynamic_bus_num = retval + 1;
|
|
up_write(&__i2c_board_lock);
|
|
|
|
retval = bus_register(&i2c_bus_type);
|
|
if (retval)
|
|
return retval;
|
|
|
|
is_registered = true;
|
|
|
|
#ifdef CONFIG_I2C_COMPAT
|
|
i2c_adapter_compat_class = class_compat_register("i2c-adapter");
|
|
if (!i2c_adapter_compat_class) {
|
|
retval = -ENOMEM;
|
|
goto bus_err;
|
|
}
|
|
#endif
|
|
retval = i2c_add_driver(&dummy_driver);
|
|
if (retval)
|
|
goto class_err;
|
|
|
|
if (IS_ENABLED(CONFIG_OF_DYNAMIC))
|
|
WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
|
|
if (IS_ENABLED(CONFIG_ACPI))
|
|
WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier));
|
|
|
|
return 0;
|
|
|
|
class_err:
|
|
#ifdef CONFIG_I2C_COMPAT
|
|
class_compat_unregister(i2c_adapter_compat_class);
|
|
bus_err:
|
|
#endif
|
|
is_registered = false;
|
|
bus_unregister(&i2c_bus_type);
|
|
return retval;
|
|
}
|
|
|
|
static void __exit i2c_exit(void)
|
|
{
|
|
if (IS_ENABLED(CONFIG_ACPI))
|
|
WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
|
|
if (IS_ENABLED(CONFIG_OF_DYNAMIC))
|
|
WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
|
|
i2c_del_driver(&dummy_driver);
|
|
#ifdef CONFIG_I2C_COMPAT
|
|
class_compat_unregister(i2c_adapter_compat_class);
|
|
#endif
|
|
bus_unregister(&i2c_bus_type);
|
|
tracepoint_synchronize_unregister();
|
|
}
|
|
|
|
/* We must initialize early, because some subsystems register i2c drivers
|
|
* in subsys_initcall() code, but are linked (and initialized) before i2c.
|
|
*/
|
|
postcore_initcall(i2c_init);
|
|
module_exit(i2c_exit);
|
|
|
|
/* ----------------------------------------------------
|
|
* the functional interface to the i2c busses.
|
|
* ----------------------------------------------------
|
|
*/
|
|
|
|
/* Check if val is exceeding the quirk IFF quirk is non 0 */
|
|
#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
|
|
|
|
static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)
|
|
{
|
|
dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",
|
|
err_msg, msg->addr, msg->len,
|
|
msg->flags & I2C_M_RD ? "read" : "write");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
|
|
{
|
|
const struct i2c_adapter_quirks *q = adap->quirks;
|
|
int max_num = q->max_num_msgs, i;
|
|
bool do_len_check = true;
|
|
|
|
if (q->flags & I2C_AQ_COMB) {
|
|
max_num = 2;
|
|
|
|
/* special checks for combined messages */
|
|
if (num == 2) {
|
|
if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)
|
|
return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");
|
|
|
|
if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))
|
|
return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");
|
|
|
|
if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
|
|
return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
|
|
|
|
if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))
|
|
return i2c_quirk_error(adap, &msgs[0], "msg too long");
|
|
|
|
if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))
|
|
return i2c_quirk_error(adap, &msgs[1], "msg too long");
|
|
|
|
do_len_check = false;
|
|
}
|
|
}
|
|
|
|
if (i2c_quirk_exceeded(num, max_num))
|
|
return i2c_quirk_error(adap, &msgs[0], "too many messages");
|
|
|
|
for (i = 0; i < num; i++) {
|
|
u16 len = msgs[i].len;
|
|
|
|
if (msgs[i].flags & I2C_M_RD) {
|
|
if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
|
|
return i2c_quirk_error(adap, &msgs[i], "msg too long");
|
|
} else {
|
|
if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
|
|
return i2c_quirk_error(adap, &msgs[i], "msg too long");
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* __i2c_transfer - unlocked flavor of i2c_transfer
|
|
* @adap: Handle to I2C bus
|
|
* @msgs: One or more messages to execute before STOP is issued to
|
|
* terminate the operation; each message begins with a START.
|
|
* @num: Number of messages to be executed.
|
|
*
|
|
* Returns negative errno, else the number of messages executed.
|
|
*
|
|
* Adapter lock must be held when calling this function. No debug logging
|
|
* takes place. adap->algo->master_xfer existence isn't checked.
|
|
*/
|
|
int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
|
|
{
|
|
unsigned long orig_jiffies;
|
|
int ret, try;
|
|
|
|
if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
|
|
return -EOPNOTSUPP;
|
|
|
|
/* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets
|
|
* enabled. This is an efficient way of keeping the for-loop from
|
|
* being executed when not needed.
|
|
*/
|
|
if (static_key_false(&i2c_trace_msg)) {
|
|
int i;
|
|
for (i = 0; i < num; i++)
|
|
if (msgs[i].flags & I2C_M_RD)
|
|
trace_i2c_read(adap, &msgs[i], i);
|
|
else
|
|
trace_i2c_write(adap, &msgs[i], i);
|
|
}
|
|
|
|
/* Retry automatically on arbitration loss */
|
|
orig_jiffies = jiffies;
|
|
for (ret = 0, try = 0; try <= adap->retries; try++) {
|
|
ret = adap->algo->master_xfer(adap, msgs, num);
|
|
if (ret != -EAGAIN)
|
|
break;
|
|
if (time_after(jiffies, orig_jiffies + adap->timeout))
|
|
break;
|
|
}
|
|
|
|
if (static_key_false(&i2c_trace_msg)) {
|
|
int i;
|
|
for (i = 0; i < ret; i++)
|
|
if (msgs[i].flags & I2C_M_RD)
|
|
trace_i2c_reply(adap, &msgs[i], i);
|
|
trace_i2c_result(adap, i, ret);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(__i2c_transfer);
|
|
|
|
/**
|
|
* i2c_transfer - execute a single or combined I2C message
|
|
* @adap: Handle to I2C bus
|
|
* @msgs: One or more messages to execute before STOP is issued to
|
|
* terminate the operation; each message begins with a START.
|
|
* @num: Number of messages to be executed.
|
|
*
|
|
* Returns negative errno, else the number of messages executed.
|
|
*
|
|
* Note that there is no requirement that each message be sent to
|
|
* the same slave address, although that is the most common model.
|
|
*/
|
|
int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
|
|
{
|
|
int ret;
|
|
|
|
/* REVISIT the fault reporting model here is weak:
|
|
*
|
|
* - When we get an error after receiving N bytes from a slave,
|
|
* there is no way to report "N".
|
|
*
|
|
* - When we get a NAK after transmitting N bytes to a slave,
|
|
* there is no way to report "N" ... or to let the master
|
|
* continue executing the rest of this combined message, if
|
|
* that's the appropriate response.
|
|
*
|
|
* - When for example "num" is two and we successfully complete
|
|
* the first message but get an error part way through the
|
|
* second, it's unclear whether that should be reported as
|
|
* one (discarding status on the second message) or errno
|
|
* (discarding status on the first one).
|
|
*/
|
|
|
|
if (adap->algo->master_xfer) {
|
|
#ifdef DEBUG
|
|
for (ret = 0; ret < num; ret++) {
|
|
dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
|
|
"len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD)
|
|
? 'R' : 'W', msgs[ret].addr, msgs[ret].len,
|
|
(msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : "");
|
|
}
|
|
#endif
|
|
|
|
if (in_atomic() || irqs_disabled()) {
|
|
ret = adap->trylock_bus(adap, I2C_LOCK_SEGMENT);
|
|
if (!ret)
|
|
/* I2C activity is ongoing. */
|
|
return -EAGAIN;
|
|
} else {
|
|
i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
|
|
}
|
|
|
|
ret = __i2c_transfer(adap, msgs, num);
|
|
i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
|
|
|
|
return ret;
|
|
} else {
|
|
dev_dbg(&adap->dev, "I2C level transfers not supported\n");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(i2c_transfer);
|
|
|
|
/**
|
|
* i2c_master_send - issue a single I2C message in master transmit mode
|
|
* @client: Handle to slave device
|
|
* @buf: Data that will be written to the slave
|
|
* @count: How many bytes to write, must be less than 64k since msg.len is u16
|
|
*
|
|
* Returns negative errno, or else the number of bytes written.
|
|
*/
|
|
int i2c_master_send(const struct i2c_client *client, const char *buf, int count)
|
|
{
|
|
int ret;
|
|
struct i2c_adapter *adap = client->adapter;
|
|
struct i2c_msg msg;
|
|
|
|
msg.addr = client->addr;
|
|
msg.flags = client->flags & I2C_M_TEN;
|
|
msg.len = count;
|
|
msg.buf = (char *)buf;
|
|
|
|
ret = i2c_transfer(adap, &msg, 1);
|
|
|
|
/*
|
|
* If everything went ok (i.e. 1 msg transmitted), return #bytes
|
|
* transmitted, else error code.
|
|
*/
|
|
return (ret == 1) ? count : ret;
|
|
}
|
|
EXPORT_SYMBOL(i2c_master_send);
|
|
|
|
/**
|
|
* i2c_master_recv - issue a single I2C message in master receive mode
|
|
* @client: Handle to slave device
|
|
* @buf: Where to store data read from slave
|
|
* @count: How many bytes to read, must be less than 64k since msg.len is u16
|
|
*
|
|
* Returns negative errno, or else the number of bytes read.
|
|
*/
|
|
int i2c_master_recv(const struct i2c_client *client, char *buf, int count)
|
|
{
|
|
struct i2c_adapter *adap = client->adapter;
|
|
struct i2c_msg msg;
|
|
int ret;
|
|
|
|
msg.addr = client->addr;
|
|
msg.flags = client->flags & I2C_M_TEN;
|
|
msg.flags |= I2C_M_RD;
|
|
msg.len = count;
|
|
msg.buf = buf;
|
|
|
|
ret = i2c_transfer(adap, &msg, 1);
|
|
|
|
/*
|
|
* If everything went ok (i.e. 1 msg received), return #bytes received,
|
|
* else error code.
|
|
*/
|
|
return (ret == 1) ? count : ret;
|
|
}
|
|
EXPORT_SYMBOL(i2c_master_recv);
|
|
|
|
/* ----------------------------------------------------
|
|
* the i2c address scanning function
|
|
* Will not work for 10-bit addresses!
|
|
* ----------------------------------------------------
|
|
*/
|
|
|
|
/*
|
|
* Legacy default probe function, mostly relevant for SMBus. The default
|
|
* probe method is a quick write, but it is known to corrupt the 24RF08
|
|
* EEPROMs due to a state machine bug, and could also irreversibly
|
|
* write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f,
|
|
* we use a short byte read instead. Also, some bus drivers don't implement
|
|
* quick write, so we fallback to a byte read in that case too.
|
|
* On x86, there is another special case for FSC hardware monitoring chips,
|
|
* which want regular byte reads (address 0x73.) Fortunately, these are the
|
|
* only known chips using this I2C address on PC hardware.
|
|
* Returns 1 if probe succeeded, 0 if not.
|
|
*/
|
|
static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr)
|
|
{
|
|
int err;
|
|
union i2c_smbus_data dummy;
|
|
|
|
#ifdef CONFIG_X86
|
|
if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON)
|
|
&& i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA))
|
|
err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
|
|
I2C_SMBUS_BYTE_DATA, &dummy);
|
|
else
|
|
#endif
|
|
if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50)
|
|
&& i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK))
|
|
err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0,
|
|
I2C_SMBUS_QUICK, NULL);
|
|
else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE))
|
|
err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
|
|
I2C_SMBUS_BYTE, &dummy);
|
|
else {
|
|
dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n",
|
|
addr);
|
|
err = -EOPNOTSUPP;
|
|
}
|
|
|
|
return err >= 0;
|
|
}
|
|
|
|
static int i2c_detect_address(struct i2c_client *temp_client,
|
|
struct i2c_driver *driver)
|
|
{
|
|
struct i2c_board_info info;
|
|
struct i2c_adapter *adapter = temp_client->adapter;
|
|
int addr = temp_client->addr;
|
|
int err;
|
|
|
|
/* Make sure the address is valid */
|
|
err = i2c_check_7bit_addr_validity_strict(addr);
|
|
if (err) {
|
|
dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
|
|
addr);
|
|
return err;
|
|
}
|
|
|
|
/* Skip if already in use (7 bit, no need to encode flags) */
|
|
if (i2c_check_addr_busy(adapter, addr))
|
|
return 0;
|
|
|
|
/* Make sure there is something at this address */
|
|
if (!i2c_default_probe(adapter, addr))
|
|
return 0;
|
|
|
|
/* Finally call the custom detection function */
|
|
memset(&info, 0, sizeof(struct i2c_board_info));
|
|
info.addr = addr;
|
|
err = driver->detect(temp_client, &info);
|
|
if (err) {
|
|
/* -ENODEV is returned if the detection fails. We catch it
|
|
here as this isn't an error. */
|
|
return err == -ENODEV ? 0 : err;
|
|
}
|
|
|
|
/* Consistency check */
|
|
if (info.type[0] == '\0') {
|
|
dev_err(&adapter->dev, "%s detection function provided "
|
|
"no name for 0x%x\n", driver->driver.name,
|
|
addr);
|
|
} else {
|
|
struct i2c_client *client;
|
|
|
|
/* Detection succeeded, instantiate the device */
|
|
if (adapter->class & I2C_CLASS_DEPRECATED)
|
|
dev_warn(&adapter->dev,
|
|
"This adapter will soon drop class based instantiation of devices. "
|
|
"Please make sure client 0x%02x gets instantiated by other means. "
|
|
"Check 'Documentation/i2c/instantiating-devices' for details.\n",
|
|
info.addr);
|
|
|
|
dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
|
|
info.type, info.addr);
|
|
client = i2c_new_device(adapter, &info);
|
|
if (client)
|
|
list_add_tail(&client->detected, &driver->clients);
|
|
else
|
|
dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
|
|
info.type, info.addr);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
|
|
{
|
|
const unsigned short *address_list;
|
|
struct i2c_client *temp_client;
|
|
int i, err = 0;
|
|
int adap_id = i2c_adapter_id(adapter);
|
|
|
|
address_list = driver->address_list;
|
|
if (!driver->detect || !address_list)
|
|
return 0;
|
|
|
|
/* Warn that the adapter lost class based instantiation */
|
|
if (adapter->class == I2C_CLASS_DEPRECATED) {
|
|
dev_dbg(&adapter->dev,
|
|
"This adapter dropped support for I2C classes and "
|
|
"won't auto-detect %s devices anymore. If you need it, check "
|
|
"'Documentation/i2c/instantiating-devices' for alternatives.\n",
|
|
driver->driver.name);
|
|
return 0;
|
|
}
|
|
|
|
/* Stop here if the classes do not match */
|
|
if (!(adapter->class & driver->class))
|
|
return 0;
|
|
|
|
/* Set up a temporary client to help detect callback */
|
|
temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
|
|
if (!temp_client)
|
|
return -ENOMEM;
|
|
temp_client->adapter = adapter;
|
|
|
|
for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
|
|
dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
|
|
"addr 0x%02x\n", adap_id, address_list[i]);
|
|
temp_client->addr = address_list[i];
|
|
err = i2c_detect_address(temp_client, driver);
|
|
if (unlikely(err))
|
|
break;
|
|
}
|
|
|
|
kfree(temp_client);
|
|
return err;
|
|
}
|
|
|
|
int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr)
|
|
{
|
|
return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0,
|
|
I2C_SMBUS_QUICK, NULL) >= 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read);
|
|
|
|
struct i2c_client *
|
|
i2c_new_probed_device(struct i2c_adapter *adap,
|
|
struct i2c_board_info *info,
|
|
unsigned short const *addr_list,
|
|
int (*probe)(struct i2c_adapter *, unsigned short addr))
|
|
{
|
|
int i;
|
|
|
|
if (!probe)
|
|
probe = i2c_default_probe;
|
|
|
|
for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
|
|
/* Check address validity */
|
|
if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) {
|
|
dev_warn(&adap->dev, "Invalid 7-bit address "
|
|
"0x%02x\n", addr_list[i]);
|
|
continue;
|
|
}
|
|
|
|
/* Check address availability (7 bit, no need to encode flags) */
|
|
if (i2c_check_addr_busy(adap, addr_list[i])) {
|
|
dev_dbg(&adap->dev, "Address 0x%02x already in "
|
|
"use, not probing\n", addr_list[i]);
|
|
continue;
|
|
}
|
|
|
|
/* Test address responsiveness */
|
|
if (probe(adap, addr_list[i]))
|
|
break;
|
|
}
|
|
|
|
if (addr_list[i] == I2C_CLIENT_END) {
|
|
dev_dbg(&adap->dev, "Probing failed, no device found\n");
|
|
return NULL;
|
|
}
|
|
|
|
info->addr = addr_list[i];
|
|
return i2c_new_device(adap, info);
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_new_probed_device);
|
|
|
|
struct i2c_adapter *i2c_get_adapter(int nr)
|
|
{
|
|
struct i2c_adapter *adapter;
|
|
|
|
mutex_lock(&core_lock);
|
|
adapter = idr_find(&i2c_adapter_idr, nr);
|
|
if (!adapter)
|
|
goto exit;
|
|
|
|
if (try_module_get(adapter->owner))
|
|
get_device(&adapter->dev);
|
|
else
|
|
adapter = NULL;
|
|
|
|
exit:
|
|
mutex_unlock(&core_lock);
|
|
return adapter;
|
|
}
|
|
EXPORT_SYMBOL(i2c_get_adapter);
|
|
|
|
void i2c_put_adapter(struct i2c_adapter *adap)
|
|
{
|
|
if (!adap)
|
|
return;
|
|
|
|
put_device(&adap->dev);
|
|
module_put(adap->owner);
|
|
}
|
|
EXPORT_SYMBOL(i2c_put_adapter);
|
|
|
|
/* The SMBus parts */
|
|
|
|
#define POLY (0x1070U << 3)
|
|
static u8 crc8(u16 data)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 8; i++) {
|
|
if (data & 0x8000)
|
|
data = data ^ POLY;
|
|
data = data << 1;
|
|
}
|
|
return (u8)(data >> 8);
|
|
}
|
|
|
|
/* Incremental CRC8 over count bytes in the array pointed to by p */
|
|
static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < count; i++)
|
|
crc = crc8((crc ^ p[i]) << 8);
|
|
return crc;
|
|
}
|
|
|
|
/* Assume a 7-bit address, which is reasonable for SMBus */
|
|
static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg)
|
|
{
|
|
/* The address will be sent first */
|
|
u8 addr = i2c_8bit_addr_from_msg(msg);
|
|
pec = i2c_smbus_pec(pec, &addr, 1);
|
|
|
|
/* The data buffer follows */
|
|
return i2c_smbus_pec(pec, msg->buf, msg->len);
|
|
}
|
|
|
|
/* Used for write only transactions */
|
|
static inline void i2c_smbus_add_pec(struct i2c_msg *msg)
|
|
{
|
|
msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg);
|
|
msg->len++;
|
|
}
|
|
|
|
/* Return <0 on CRC error
|
|
If there was a write before this read (most cases) we need to take the
|
|
partial CRC from the write part into account.
|
|
Note that this function does modify the message (we need to decrease the
|
|
message length to hide the CRC byte from the caller). */
|
|
static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
|
|
{
|
|
u8 rpec = msg->buf[--msg->len];
|
|
cpec = i2c_smbus_msg_pec(cpec, msg);
|
|
|
|
if (rpec != cpec) {
|
|
pr_debug("Bad PEC 0x%02x vs. 0x%02x\n",
|
|
rpec, cpec);
|
|
return -EBADMSG;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* i2c_smbus_read_byte - SMBus "receive byte" protocol
|
|
* @client: Handle to slave device
|
|
*
|
|
* This executes the SMBus "receive byte" protocol, returning negative errno
|
|
* else the byte received from the device.
|
|
*/
|
|
s32 i2c_smbus_read_byte(const struct i2c_client *client)
|
|
{
|
|
union i2c_smbus_data data;
|
|
int status;
|
|
|
|
status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
I2C_SMBUS_READ, 0,
|
|
I2C_SMBUS_BYTE, &data);
|
|
return (status < 0) ? status : data.byte;
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_read_byte);
|
|
|
|
/**
|
|
* i2c_smbus_write_byte - SMBus "send byte" protocol
|
|
* @client: Handle to slave device
|
|
* @value: Byte to be sent
|
|
*
|
|
* This executes the SMBus "send byte" protocol, returning negative errno
|
|
* else zero on success.
|
|
*/
|
|
s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value)
|
|
{
|
|
return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_write_byte);
|
|
|
|
/**
|
|
* i2c_smbus_read_byte_data - SMBus "read byte" protocol
|
|
* @client: Handle to slave device
|
|
* @command: Byte interpreted by slave
|
|
*
|
|
* This executes the SMBus "read byte" protocol, returning negative errno
|
|
* else a data byte received from the device.
|
|
*/
|
|
s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command)
|
|
{
|
|
union i2c_smbus_data data;
|
|
int status;
|
|
|
|
status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
I2C_SMBUS_READ, command,
|
|
I2C_SMBUS_BYTE_DATA, &data);
|
|
return (status < 0) ? status : data.byte;
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_read_byte_data);
|
|
|
|
/**
|
|
* i2c_smbus_write_byte_data - SMBus "write byte" protocol
|
|
* @client: Handle to slave device
|
|
* @command: Byte interpreted by slave
|
|
* @value: Byte being written
|
|
*
|
|
* This executes the SMBus "write byte" protocol, returning negative errno
|
|
* else zero on success.
|
|
*/
|
|
s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command,
|
|
u8 value)
|
|
{
|
|
union i2c_smbus_data data;
|
|
data.byte = value;
|
|
return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
I2C_SMBUS_WRITE, command,
|
|
I2C_SMBUS_BYTE_DATA, &data);
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_write_byte_data);
|
|
|
|
/**
|
|
* i2c_smbus_read_word_data - SMBus "read word" protocol
|
|
* @client: Handle to slave device
|
|
* @command: Byte interpreted by slave
|
|
*
|
|
* This executes the SMBus "read word" protocol, returning negative errno
|
|
* else a 16-bit unsigned "word" received from the device.
|
|
*/
|
|
s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command)
|
|
{
|
|
union i2c_smbus_data data;
|
|
int status;
|
|
|
|
status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
I2C_SMBUS_READ, command,
|
|
I2C_SMBUS_WORD_DATA, &data);
|
|
return (status < 0) ? status : data.word;
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_read_word_data);
|
|
|
|
/**
|
|
* i2c_smbus_write_word_data - SMBus "write word" protocol
|
|
* @client: Handle to slave device
|
|
* @command: Byte interpreted by slave
|
|
* @value: 16-bit "word" being written
|
|
*
|
|
* This executes the SMBus "write word" protocol, returning negative errno
|
|
* else zero on success.
|
|
*/
|
|
s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command,
|
|
u16 value)
|
|
{
|
|
union i2c_smbus_data data;
|
|
data.word = value;
|
|
return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
I2C_SMBUS_WRITE, command,
|
|
I2C_SMBUS_WORD_DATA, &data);
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_write_word_data);
|
|
|
|
/**
|
|
* i2c_smbus_read_block_data - SMBus "block read" protocol
|
|
* @client: Handle to slave device
|
|
* @command: Byte interpreted by slave
|
|
* @values: Byte array into which data will be read; big enough to hold
|
|
* the data returned by the slave. SMBus allows at most 32 bytes.
|
|
*
|
|
* This executes the SMBus "block read" protocol, returning negative errno
|
|
* else the number of data bytes in the slave's response.
|
|
*
|
|
* Note that using this function requires that the client's adapter support
|
|
* the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers
|
|
* support this; its emulation through I2C messaging relies on a specific
|
|
* mechanism (I2C_M_RECV_LEN) which may not be implemented.
|
|
*/
|
|
s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command,
|
|
u8 *values)
|
|
{
|
|
union i2c_smbus_data data;
|
|
int status;
|
|
|
|
status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
I2C_SMBUS_READ, command,
|
|
I2C_SMBUS_BLOCK_DATA, &data);
|
|
if (status)
|
|
return status;
|
|
|
|
memcpy(values, &data.block[1], data.block[0]);
|
|
return data.block[0];
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_read_block_data);
|
|
|
|
/**
|
|
* i2c_smbus_write_block_data - SMBus "block write" protocol
|
|
* @client: Handle to slave device
|
|
* @command: Byte interpreted by slave
|
|
* @length: Size of data block; SMBus allows at most 32 bytes
|
|
* @values: Byte array which will be written.
|
|
*
|
|
* This executes the SMBus "block write" protocol, returning negative errno
|
|
* else zero on success.
|
|
*/
|
|
s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command,
|
|
u8 length, const u8 *values)
|
|
{
|
|
union i2c_smbus_data data;
|
|
|
|
if (length > I2C_SMBUS_BLOCK_MAX)
|
|
length = I2C_SMBUS_BLOCK_MAX;
|
|
data.block[0] = length;
|
|
memcpy(&data.block[1], values, length);
|
|
return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
I2C_SMBUS_WRITE, command,
|
|
I2C_SMBUS_BLOCK_DATA, &data);
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_write_block_data);
|
|
|
|
/* Returns the number of read bytes */
|
|
s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command,
|
|
u8 length, u8 *values)
|
|
{
|
|
union i2c_smbus_data data;
|
|
int status;
|
|
|
|
if (length > I2C_SMBUS_BLOCK_MAX)
|
|
length = I2C_SMBUS_BLOCK_MAX;
|
|
data.block[0] = length;
|
|
status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
I2C_SMBUS_READ, command,
|
|
I2C_SMBUS_I2C_BLOCK_DATA, &data);
|
|
if (status < 0)
|
|
return status;
|
|
|
|
memcpy(values, &data.block[1], data.block[0]);
|
|
return data.block[0];
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
|
|
|
|
s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command,
|
|
u8 length, const u8 *values)
|
|
{
|
|
union i2c_smbus_data data;
|
|
|
|
if (length > I2C_SMBUS_BLOCK_MAX)
|
|
length = I2C_SMBUS_BLOCK_MAX;
|
|
data.block[0] = length;
|
|
memcpy(data.block + 1, values, length);
|
|
return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
|
|
I2C_SMBUS_WRITE, command,
|
|
I2C_SMBUS_I2C_BLOCK_DATA, &data);
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
|
|
|
|
/* Simulate a SMBus command using the i2c protocol
|
|
No checking of parameters is done! */
|
|
static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
|
|
unsigned short flags,
|
|
char read_write, u8 command, int size,
|
|
union i2c_smbus_data *data)
|
|
{
|
|
/* So we need to generate a series of msgs. In the case of writing, we
|
|
need to use only one message; when reading, we need two. We initialize
|
|
most things with sane defaults, to keep the code below somewhat
|
|
simpler. */
|
|
unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
|
|
unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
|
|
int num = read_write == I2C_SMBUS_READ ? 2 : 1;
|
|
int i;
|
|
u8 partial_pec = 0;
|
|
int status;
|
|
struct i2c_msg msg[2] = {
|
|
{
|
|
.addr = addr,
|
|
.flags = flags,
|
|
.len = 1,
|
|
.buf = msgbuf0,
|
|
}, {
|
|
.addr = addr,
|
|
.flags = flags | I2C_M_RD,
|
|
.len = 0,
|
|
.buf = msgbuf1,
|
|
},
|
|
};
|
|
|
|
msgbuf0[0] = command;
|
|
switch (size) {
|
|
case I2C_SMBUS_QUICK:
|
|
msg[0].len = 0;
|
|
/* Special case: The read/write field is used as data */
|
|
msg[0].flags = flags | (read_write == I2C_SMBUS_READ ?
|
|
I2C_M_RD : 0);
|
|
num = 1;
|
|
break;
|
|
case I2C_SMBUS_BYTE:
|
|
if (read_write == I2C_SMBUS_READ) {
|
|
/* Special case: only a read! */
|
|
msg[0].flags = I2C_M_RD | flags;
|
|
num = 1;
|
|
}
|
|
break;
|
|
case I2C_SMBUS_BYTE_DATA:
|
|
if (read_write == I2C_SMBUS_READ)
|
|
msg[1].len = 1;
|
|
else {
|
|
msg[0].len = 2;
|
|
msgbuf0[1] = data->byte;
|
|
}
|
|
break;
|
|
case I2C_SMBUS_WORD_DATA:
|
|
if (read_write == I2C_SMBUS_READ)
|
|
msg[1].len = 2;
|
|
else {
|
|
msg[0].len = 3;
|
|
msgbuf0[1] = data->word & 0xff;
|
|
msgbuf0[2] = data->word >> 8;
|
|
}
|
|
break;
|
|
case I2C_SMBUS_PROC_CALL:
|
|
num = 2; /* Special case */
|
|
read_write = I2C_SMBUS_READ;
|
|
msg[0].len = 3;
|
|
msg[1].len = 2;
|
|
msgbuf0[1] = data->word & 0xff;
|
|
msgbuf0[2] = data->word >> 8;
|
|
break;
|
|
case I2C_SMBUS_BLOCK_DATA:
|
|
if (read_write == I2C_SMBUS_READ) {
|
|
msg[1].flags |= I2C_M_RECV_LEN;
|
|
msg[1].len = 1; /* block length will be added by
|
|
the underlying bus driver */
|
|
} else {
|
|
msg[0].len = data->block[0] + 2;
|
|
if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
|
|
dev_err(&adapter->dev,
|
|
"Invalid block write size %d\n",
|
|
data->block[0]);
|
|
return -EINVAL;
|
|
}
|
|
for (i = 1; i < msg[0].len; i++)
|
|
msgbuf0[i] = data->block[i-1];
|
|
}
|
|
break;
|
|
case I2C_SMBUS_BLOCK_PROC_CALL:
|
|
num = 2; /* Another special case */
|
|
read_write = I2C_SMBUS_READ;
|
|
if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
|
|
dev_err(&adapter->dev,
|
|
"Invalid block write size %d\n",
|
|
data->block[0]);
|
|
return -EINVAL;
|
|
}
|
|
msg[0].len = data->block[0] + 2;
|
|
for (i = 1; i < msg[0].len; i++)
|
|
msgbuf0[i] = data->block[i-1];
|
|
msg[1].flags |= I2C_M_RECV_LEN;
|
|
msg[1].len = 1; /* block length will be added by
|
|
the underlying bus driver */
|
|
break;
|
|
case I2C_SMBUS_I2C_BLOCK_DATA:
|
|
if (read_write == I2C_SMBUS_READ) {
|
|
msg[1].len = data->block[0];
|
|
} else {
|
|
msg[0].len = data->block[0] + 1;
|
|
if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
|
|
dev_err(&adapter->dev,
|
|
"Invalid block write size %d\n",
|
|
data->block[0]);
|
|
return -EINVAL;
|
|
}
|
|
for (i = 1; i <= data->block[0]; i++)
|
|
msgbuf0[i] = data->block[i];
|
|
}
|
|
break;
|
|
default:
|
|
dev_err(&adapter->dev, "Unsupported transaction %d\n", size);
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
|
|
&& size != I2C_SMBUS_I2C_BLOCK_DATA);
|
|
if (i) {
|
|
/* Compute PEC if first message is a write */
|
|
if (!(msg[0].flags & I2C_M_RD)) {
|
|
if (num == 1) /* Write only */
|
|
i2c_smbus_add_pec(&msg[0]);
|
|
else /* Write followed by read */
|
|
partial_pec = i2c_smbus_msg_pec(0, &msg[0]);
|
|
}
|
|
/* Ask for PEC if last message is a read */
|
|
if (msg[num-1].flags & I2C_M_RD)
|
|
msg[num-1].len++;
|
|
}
|
|
|
|
status = i2c_transfer(adapter, msg, num);
|
|
if (status < 0)
|
|
return status;
|
|
|
|
/* Check PEC if last message is a read */
|
|
if (i && (msg[num-1].flags & I2C_M_RD)) {
|
|
status = i2c_smbus_check_pec(partial_pec, &msg[num-1]);
|
|
if (status < 0)
|
|
return status;
|
|
}
|
|
|
|
if (read_write == I2C_SMBUS_READ)
|
|
switch (size) {
|
|
case I2C_SMBUS_BYTE:
|
|
data->byte = msgbuf0[0];
|
|
break;
|
|
case I2C_SMBUS_BYTE_DATA:
|
|
data->byte = msgbuf1[0];
|
|
break;
|
|
case I2C_SMBUS_WORD_DATA:
|
|
case I2C_SMBUS_PROC_CALL:
|
|
data->word = msgbuf1[0] | (msgbuf1[1] << 8);
|
|
break;
|
|
case I2C_SMBUS_I2C_BLOCK_DATA:
|
|
for (i = 0; i < data->block[0]; i++)
|
|
data->block[i+1] = msgbuf1[i];
|
|
break;
|
|
case I2C_SMBUS_BLOCK_DATA:
|
|
case I2C_SMBUS_BLOCK_PROC_CALL:
|
|
for (i = 0; i < msgbuf1[0] + 1; i++)
|
|
data->block[i] = msgbuf1[i];
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* i2c_smbus_xfer - execute SMBus protocol operations
|
|
* @adapter: Handle to I2C bus
|
|
* @addr: Address of SMBus slave on that bus
|
|
* @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC)
|
|
* @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE
|
|
* @command: Byte interpreted by slave, for protocols which use such bytes
|
|
* @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL
|
|
* @data: Data to be read or written
|
|
*
|
|
* This executes an SMBus protocol operation, and returns a negative
|
|
* errno code else zero on success.
|
|
*/
|
|
s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
|
|
char read_write, u8 command, int protocol,
|
|
union i2c_smbus_data *data)
|
|
{
|
|
unsigned long orig_jiffies;
|
|
int try;
|
|
s32 res;
|
|
|
|
/* If enabled, the following two tracepoints are conditional on
|
|
* read_write and protocol.
|
|
*/
|
|
trace_smbus_write(adapter, addr, flags, read_write,
|
|
command, protocol, data);
|
|
trace_smbus_read(adapter, addr, flags, read_write,
|
|
command, protocol);
|
|
|
|
flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB;
|
|
|
|
if (adapter->algo->smbus_xfer) {
|
|
i2c_lock_bus(adapter, I2C_LOCK_SEGMENT);
|
|
|
|
/* Retry automatically on arbitration loss */
|
|
orig_jiffies = jiffies;
|
|
for (res = 0, try = 0; try <= adapter->retries; try++) {
|
|
res = adapter->algo->smbus_xfer(adapter, addr, flags,
|
|
read_write, command,
|
|
protocol, data);
|
|
if (res != -EAGAIN)
|
|
break;
|
|
if (time_after(jiffies,
|
|
orig_jiffies + adapter->timeout))
|
|
break;
|
|
}
|
|
i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT);
|
|
|
|
if (res != -EOPNOTSUPP || !adapter->algo->master_xfer)
|
|
goto trace;
|
|
/*
|
|
* Fall back to i2c_smbus_xfer_emulated if the adapter doesn't
|
|
* implement native support for the SMBus operation.
|
|
*/
|
|
}
|
|
|
|
res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
|
|
command, protocol, data);
|
|
|
|
trace:
|
|
/* If enabled, the reply tracepoint is conditional on read_write. */
|
|
trace_smbus_reply(adapter, addr, flags, read_write,
|
|
command, protocol, data);
|
|
trace_smbus_result(adapter, addr, flags, read_write,
|
|
command, protocol, res);
|
|
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_xfer);
|
|
|
|
/**
|
|
* i2c_smbus_read_i2c_block_data_or_emulated - read block or emulate
|
|
* @client: Handle to slave device
|
|
* @command: Byte interpreted by slave
|
|
* @length: Size of data block; SMBus allows at most I2C_SMBUS_BLOCK_MAX bytes
|
|
* @values: Byte array into which data will be read; big enough to hold
|
|
* the data returned by the slave. SMBus allows at most
|
|
* I2C_SMBUS_BLOCK_MAX bytes.
|
|
*
|
|
* This executes the SMBus "block read" protocol if supported by the adapter.
|
|
* If block read is not supported, it emulates it using either word or byte
|
|
* read protocols depending on availability.
|
|
*
|
|
* The addresses of the I2C slave device that are accessed with this function
|
|
* must be mapped to a linear region, so that a block read will have the same
|
|
* effect as a byte read. Before using this function you must double-check
|
|
* if the I2C slave does support exchanging a block transfer with a byte
|
|
* transfer.
|
|
*/
|
|
s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
|
|
u8 command, u8 length, u8 *values)
|
|
{
|
|
u8 i = 0;
|
|
int status;
|
|
|
|
if (length > I2C_SMBUS_BLOCK_MAX)
|
|
length = I2C_SMBUS_BLOCK_MAX;
|
|
|
|
if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
|
|
return i2c_smbus_read_i2c_block_data(client, command, length, values);
|
|
|
|
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA))
|
|
return -EOPNOTSUPP;
|
|
|
|
if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)) {
|
|
while ((i + 2) <= length) {
|
|
status = i2c_smbus_read_word_data(client, command + i);
|
|
if (status < 0)
|
|
return status;
|
|
values[i] = status & 0xff;
|
|
values[i + 1] = status >> 8;
|
|
i += 2;
|
|
}
|
|
}
|
|
|
|
while (i < length) {
|
|
status = i2c_smbus_read_byte_data(client, command + i);
|
|
if (status < 0)
|
|
return status;
|
|
values[i] = status;
|
|
i++;
|
|
}
|
|
|
|
return i;
|
|
}
|
|
EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data_or_emulated);
|
|
|
|
#if IS_ENABLED(CONFIG_I2C_SLAVE)
|
|
int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb)
|
|
{
|
|
int ret;
|
|
|
|
if (!client || !slave_cb) {
|
|
WARN(1, "insufficent data\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!(client->flags & I2C_CLIENT_SLAVE))
|
|
dev_warn(&client->dev, "%s: client slave flag not set. You might see address collisions\n",
|
|
__func__);
|
|
|
|
if (!(client->flags & I2C_CLIENT_TEN)) {
|
|
/* Enforce stricter address checking */
|
|
ret = i2c_check_7bit_addr_validity_strict(client->addr);
|
|
if (ret) {
|
|
dev_err(&client->dev, "%s: invalid address\n", __func__);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (!client->adapter->algo->reg_slave) {
|
|
dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
client->slave_cb = slave_cb;
|
|
|
|
i2c_lock_adapter(client->adapter);
|
|
ret = client->adapter->algo->reg_slave(client);
|
|
i2c_unlock_adapter(client->adapter);
|
|
|
|
if (ret) {
|
|
client->slave_cb = NULL;
|
|
dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_slave_register);
|
|
|
|
int i2c_slave_unregister(struct i2c_client *client)
|
|
{
|
|
int ret;
|
|
|
|
if (!client->adapter->algo->unreg_slave) {
|
|
dev_err(&client->dev, "%s: not supported by adapter\n", __func__);
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
i2c_lock_adapter(client->adapter);
|
|
ret = client->adapter->algo->unreg_slave(client);
|
|
i2c_unlock_adapter(client->adapter);
|
|
|
|
if (ret == 0)
|
|
client->slave_cb = NULL;
|
|
else
|
|
dev_err(&client->dev, "%s: adapter returned error %d\n", __func__, ret);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(i2c_slave_unregister);
|
|
#endif
|
|
|
|
MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
|
|
MODULE_DESCRIPTION("I2C-Bus main module");
|
|
MODULE_LICENSE("GPL");
|