forked from Minki/linux
w1: Add 1-wire slave device driver for DS28E04-100
Signed-off-by: Markus Franke <franm@hrz.tu-chemnitz.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Markus Franke
Greg Kroah-Hartman
parent
a59d6293e5
commit
fbf7f7b4e2
15
Documentation/ABI/stable/sysfs-driver-w1_ds28e04
Normal file
15
Documentation/ABI/stable/sysfs-driver-w1_ds28e04
Normal file
@ -0,0 +1,15 @@
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What: /sys/bus/w1/devices/.../pio
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Date: May 2012
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Contact: Markus Franke <franm@hrz.tu-chemnitz.de>
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Description: read/write the contents of the two PIO's of the DS28E04-100
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see Documentation/w1/slaves/w1_ds28e04 for detailed information
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Users: any user space application which wants to communicate with DS28E04-100
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What: /sys/bus/w1/devices/.../eeprom
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Date: May 2012
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Contact: Markus Franke <franm@hrz.tu-chemnitz.de>
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Description: read/write the contents of the EEPROM memory of the DS28E04-100
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see Documentation/w1/slaves/w1_ds28e04 for detailed information
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Users: any user space application which wants to communicate with DS28E04-100
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36
Documentation/w1/slaves/w1_ds28e04
Normal file
36
Documentation/w1/slaves/w1_ds28e04
Normal file
@ -0,0 +1,36 @@
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Kernel driver w1_ds28e04
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========================
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Supported chips:
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* Maxim DS28E04-100 4096-Bit Addressable 1-Wire EEPROM with PIO
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supported family codes:
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W1_FAMILY_DS28E04 0x1C
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Author: Markus Franke, <franke.m@sebakmt.com> <franm@hrz.tu-chemnitz.de>
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Description
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-----------
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Support is provided through the sysfs files "eeprom" and "pio". CRC checking
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during memory accesses can optionally be enabled/disabled via the device
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attribute "crccheck". The strong pull-up can optionally be enabled/disabled
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via the module parameter "w1_strong_pullup".
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Memory Access
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A read operation on the "eeprom" file reads the given amount of bytes
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from the EEPROM of the DS28E04.
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A write operation on the "eeprom" file writes the given byte sequence
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to the EEPROM of the DS28E04. If CRC checking mode is enabled only
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fully alligned blocks of 32 bytes with valid CRC16 values (in bytes 30
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and 31) are allowed to be written.
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PIO Access
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The 2 PIOs of the DS28E04-100 are accessible via the "pio" sysfs file.
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The current status of the PIO's is returned as an 8 bit value. Bit 0/1
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represent the state of PIO_0/PIO_1. Bits 2..7 do not care. The PIO's are
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driven low-active, i.e. the driver delivers/expects low-active values.
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@ -94,6 +94,19 @@ config W1_SLAVE_DS2781
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If you are unsure, say N.
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config W1_SLAVE_DS28E04
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tristate "4096-Bit Addressable 1-Wire EEPROM with PIO (DS28E04-100)"
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depends on W1
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select CRC16
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help
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If you enable this you will have the DS28E04-100
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chip support.
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Say Y here if you want to use a 1-wire
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4kb EEPROM with PIO family device (DS28E04).
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If you are unsure, say N.
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config W1_SLAVE_BQ27000
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tristate "BQ27000 slave support"
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depends on W1
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@ -12,3 +12,4 @@ obj-$(CONFIG_W1_SLAVE_DS2760) += w1_ds2760.o
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obj-$(CONFIG_W1_SLAVE_DS2780) += w1_ds2780.o
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obj-$(CONFIG_W1_SLAVE_DS2781) += w1_ds2781.o
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obj-$(CONFIG_W1_SLAVE_BQ27000) += w1_bq27000.o
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obj-$(CONFIG_W1_SLAVE_DS28E04) += w1_ds28e04.o
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469
drivers/w1/slaves/w1_ds28e04.c
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469
drivers/w1/slaves/w1_ds28e04.c
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@ -0,0 +1,469 @@
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/*
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* w1_ds28e04.c - w1 family 1C (DS28E04) driver
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*
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* Copyright (c) 2012 Markus Franke <franke.m@sebakmt.com>
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*
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* This source code is licensed under the GNU General Public License,
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* Version 2. See the file COPYING for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/device.h>
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#include <linux/types.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/crc16.h>
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#include <linux/uaccess.h>
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#define CRC16_INIT 0
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#define CRC16_VALID 0xb001
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#include "../w1.h"
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#include "../w1_int.h"
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#include "../w1_family.h"
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Markus Franke <franke.m@sebakmt.com>, <franm@hrz.tu-chemnitz.de>");
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MODULE_DESCRIPTION("w1 family 1C driver for DS28E04, 4kb EEPROM and PIO");
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/* Allow the strong pullup to be disabled, but default to enabled.
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* If it was disabled a parasite powered device might not get the required
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* current to copy the data from the scratchpad to EEPROM. If it is enabled
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* parasite powered devices have a better chance of getting the current
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* required.
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*/
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static int w1_strong_pullup = 1;
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module_param_named(strong_pullup, w1_strong_pullup, int, 0);
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/* enable/disable CRC checking on DS28E04-100 memory accesses */
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static char w1_enable_crccheck = 1;
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#define W1_EEPROM_SIZE 512
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#define W1_PAGE_COUNT 16
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#define W1_PAGE_SIZE 32
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#define W1_PAGE_BITS 5
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#define W1_PAGE_MASK 0x1F
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#define W1_F1C_READ_EEPROM 0xF0
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#define W1_F1C_WRITE_SCRATCH 0x0F
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#define W1_F1C_READ_SCRATCH 0xAA
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#define W1_F1C_COPY_SCRATCH 0x55
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#define W1_F1C_ACCESS_WRITE 0x5A
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#define W1_1C_REG_LOGIC_STATE 0x220
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struct w1_f1C_data {
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u8 memory[W1_EEPROM_SIZE];
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u32 validcrc;
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};
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/**
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* Check the file size bounds and adjusts count as needed.
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* This would not be needed if the file size didn't reset to 0 after a write.
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*/
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static inline size_t w1_f1C_fix_count(loff_t off, size_t count, size_t size)
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{
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if (off > size)
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return 0;
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if ((off + count) > size)
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return size - off;
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return count;
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}
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static int w1_f1C_refresh_block(struct w1_slave *sl, struct w1_f1C_data *data,
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int block)
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{
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u8 wrbuf[3];
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int off = block * W1_PAGE_SIZE;
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if (data->validcrc & (1 << block))
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return 0;
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if (w1_reset_select_slave(sl)) {
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data->validcrc = 0;
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return -EIO;
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}
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wrbuf[0] = W1_F1C_READ_EEPROM;
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wrbuf[1] = off & 0xff;
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wrbuf[2] = off >> 8;
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w1_write_block(sl->master, wrbuf, 3);
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w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);
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/* cache the block if the CRC is valid */
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if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
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data->validcrc |= (1 << block);
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return 0;
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}
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static int w1_f1C_read(struct w1_slave *sl, int addr, int len, char *data)
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{
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u8 wrbuf[3];
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/* read directly from the EEPROM */
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if (w1_reset_select_slave(sl))
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return -EIO;
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wrbuf[0] = W1_F1C_READ_EEPROM;
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wrbuf[1] = addr & 0xff;
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wrbuf[2] = addr >> 8;
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w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
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return w1_read_block(sl->master, data, len);
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}
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static ssize_t w1_f1C_read_bin(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t off, size_t count)
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{
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struct w1_slave *sl = kobj_to_w1_slave(kobj);
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struct w1_f1C_data *data = sl->family_data;
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int i, min_page, max_page;
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count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE);
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if (count == 0)
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return 0;
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mutex_lock(&sl->master->mutex);
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if (w1_enable_crccheck) {
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min_page = (off >> W1_PAGE_BITS);
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max_page = (off + count - 1) >> W1_PAGE_BITS;
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for (i = min_page; i <= max_page; i++) {
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if (w1_f1C_refresh_block(sl, data, i)) {
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count = -EIO;
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goto out_up;
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}
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}
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memcpy(buf, &data->memory[off], count);
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} else {
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count = w1_f1C_read(sl, off, count, buf);
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}
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out_up:
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mutex_unlock(&sl->master->mutex);
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return count;
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}
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/**
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* Writes to the scratchpad and reads it back for verification.
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* Then copies the scratchpad to EEPROM.
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* The data must be on one page.
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* The master must be locked.
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*
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* @param sl The slave structure
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* @param addr Address for the write
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* @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
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* @param data The data to write
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* @return 0=Success -1=failure
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*/
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static int w1_f1C_write(struct w1_slave *sl, int addr, int len, const u8 *data)
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{
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u8 wrbuf[4];
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u8 rdbuf[W1_PAGE_SIZE + 3];
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u8 es = (addr + len - 1) & 0x1f;
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unsigned int tm = 10;
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int i;
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struct w1_f1C_data *f1C = sl->family_data;
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/* Write the data to the scratchpad */
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if (w1_reset_select_slave(sl))
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return -1;
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wrbuf[0] = W1_F1C_WRITE_SCRATCH;
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wrbuf[1] = addr & 0xff;
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wrbuf[2] = addr >> 8;
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w1_write_block(sl->master, wrbuf, 3);
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w1_write_block(sl->master, data, len);
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/* Read the scratchpad and verify */
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if (w1_reset_select_slave(sl))
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return -1;
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w1_write_8(sl->master, W1_F1C_READ_SCRATCH);
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w1_read_block(sl->master, rdbuf, len + 3);
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/* Compare what was read against the data written */
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if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
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(rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
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return -1;
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/* Copy the scratchpad to EEPROM */
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if (w1_reset_select_slave(sl))
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return -1;
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wrbuf[0] = W1_F1C_COPY_SCRATCH;
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wrbuf[3] = es;
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for (i = 0; i < sizeof(wrbuf); ++i) {
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/* issue 10ms strong pullup (or delay) on the last byte
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for writing the data from the scratchpad to EEPROM */
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if (w1_strong_pullup && i == sizeof(wrbuf)-1)
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w1_next_pullup(sl->master, tm);
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w1_write_8(sl->master, wrbuf[i]);
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}
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if (!w1_strong_pullup)
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msleep(tm);
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if (w1_enable_crccheck) {
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/* invalidate cached data */
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f1C->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
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}
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/* Reset the bus to wake up the EEPROM (this may not be needed) */
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w1_reset_bus(sl->master);
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return 0;
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}
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static ssize_t w1_f1C_write_bin(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t off, size_t count)
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{
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struct w1_slave *sl = kobj_to_w1_slave(kobj);
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int addr, len, idx;
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count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE);
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if (count == 0)
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return 0;
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if (w1_enable_crccheck) {
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/* can only write full blocks in cached mode */
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if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
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dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
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(int)off, count);
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return -EINVAL;
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}
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/* make sure the block CRCs are valid */
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for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
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if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE)
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!= CRC16_VALID) {
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dev_err(&sl->dev, "bad CRC at offset %d\n",
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(int)off);
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return -EINVAL;
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}
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}
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}
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mutex_lock(&sl->master->mutex);
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/* Can only write data to one page at a time */
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idx = 0;
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while (idx < count) {
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addr = off + idx;
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len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
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if (len > (count - idx))
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len = count - idx;
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if (w1_f1C_write(sl, addr, len, &buf[idx]) < 0) {
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count = -EIO;
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goto out_up;
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}
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idx += len;
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}
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out_up:
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mutex_unlock(&sl->master->mutex);
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return count;
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}
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static ssize_t w1_f1C_read_pio(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t off, size_t count)
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{
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struct w1_slave *sl = kobj_to_w1_slave(kobj);
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int ret;
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/* check arguments */
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if (off != 0 || count != 1 || buf == NULL)
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return -EINVAL;
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mutex_lock(&sl->master->mutex);
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ret = w1_f1C_read(sl, W1_1C_REG_LOGIC_STATE, count, buf);
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mutex_unlock(&sl->master->mutex);
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return ret;
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}
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static ssize_t w1_f1C_write_pio(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t off, size_t count)
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{
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struct w1_slave *sl = kobj_to_w1_slave(kobj);
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u8 wrbuf[3];
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u8 ack;
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/* check arguments */
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if (off != 0 || count != 1 || buf == NULL)
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return -EINVAL;
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mutex_lock(&sl->master->mutex);
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/* Write the PIO data */
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if (w1_reset_select_slave(sl)) {
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mutex_unlock(&sl->master->mutex);
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return -1;
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}
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/* set bit 7..2 to value '1' */
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*buf = *buf | 0xFC;
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wrbuf[0] = W1_F1C_ACCESS_WRITE;
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wrbuf[1] = *buf;
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wrbuf[2] = ~(*buf);
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w1_write_block(sl->master, wrbuf, 3);
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w1_read_block(sl->master, &ack, sizeof(ack));
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mutex_unlock(&sl->master->mutex);
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/* check for acknowledgement */
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if (ack != 0xAA)
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return -EIO;
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return count;
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}
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static ssize_t w1_f1C_show_crccheck(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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if (put_user(w1_enable_crccheck + 0x30, buf))
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return -EFAULT;
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return sizeof(w1_enable_crccheck);
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}
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static ssize_t w1_f1C_store_crccheck(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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char val;
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if (count != 1 || !buf)
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return -EINVAL;
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if (get_user(val, buf))
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return -EFAULT;
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/* convert to decimal */
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val = val - 0x30;
|
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if (val != 0 && val != 1)
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return -EINVAL;
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|
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/* set the new value */
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w1_enable_crccheck = val;
|
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return sizeof(w1_enable_crccheck);
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}
|
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#define NB_SYSFS_BIN_FILES 2
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static struct bin_attribute w1_f1C_bin_attr[NB_SYSFS_BIN_FILES] = {
|
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{
|
||||
.attr = {
|
||||
.name = "eeprom",
|
||||
.mode = S_IRUGO | S_IWUSR,
|
||||
},
|
||||
.size = W1_EEPROM_SIZE,
|
||||
.read = w1_f1C_read_bin,
|
||||
.write = w1_f1C_write_bin,
|
||||
},
|
||||
{
|
||||
.attr = {
|
||||
.name = "pio",
|
||||
.mode = S_IRUGO | S_IWUSR,
|
||||
},
|
||||
.size = 1,
|
||||
.read = w1_f1C_read_pio,
|
||||
.write = w1_f1C_write_pio,
|
||||
}
|
||||
};
|
||||
|
||||
static DEVICE_ATTR(crccheck, S_IWUSR | S_IRUGO,
|
||||
w1_f1C_show_crccheck, w1_f1C_store_crccheck);
|
||||
|
||||
static int w1_f1C_add_slave(struct w1_slave *sl)
|
||||
{
|
||||
int err = 0;
|
||||
int i;
|
||||
struct w1_f1C_data *data = NULL;
|
||||
|
||||
if (w1_enable_crccheck) {
|
||||
data = kzalloc(sizeof(struct w1_f1C_data), GFP_KERNEL);
|
||||
if (!data)
|
||||
return -ENOMEM;
|
||||
sl->family_data = data;
|
||||
}
|
||||
|
||||
/* create binary sysfs attributes */
|
||||
for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
|
||||
err = sysfs_create_bin_file(
|
||||
&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
|
||||
|
||||
if (!err) {
|
||||
/* create device attributes */
|
||||
err = device_create_file(&sl->dev, &dev_attr_crccheck);
|
||||
}
|
||||
|
||||
if (err) {
|
||||
/* remove binary sysfs attributes */
|
||||
for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
|
||||
sysfs_remove_bin_file(
|
||||
&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
|
||||
|
||||
kfree(data);
|
||||
}
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
static void w1_f1C_remove_slave(struct w1_slave *sl)
|
||||
{
|
||||
int i;
|
||||
|
||||
kfree(sl->family_data);
|
||||
sl->family_data = NULL;
|
||||
|
||||
/* remove device attributes */
|
||||
device_remove_file(&sl->dev, &dev_attr_crccheck);
|
||||
|
||||
/* remove binary sysfs attributes */
|
||||
for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
|
||||
sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
|
||||
}
|
||||
|
||||
static struct w1_family_ops w1_f1C_fops = {
|
||||
.add_slave = w1_f1C_add_slave,
|
||||
.remove_slave = w1_f1C_remove_slave,
|
||||
};
|
||||
|
||||
static struct w1_family w1_family_1C = {
|
||||
.fid = W1_FAMILY_DS28E04,
|
||||
.fops = &w1_f1C_fops,
|
||||
};
|
||||
|
||||
static int __init w1_f1C_init(void)
|
||||
{
|
||||
return w1_register_family(&w1_family_1C);
|
||||
}
|
||||
|
||||
static void __exit w1_f1C_fini(void)
|
||||
{
|
||||
w1_unregister_family(&w1_family_1C);
|
||||
}
|
||||
|
||||
module_init(w1_f1C_init);
|
||||
module_exit(w1_f1C_fini);
|
||||
@ -30,6 +30,7 @@
|
||||
#define W1_FAMILY_SMEM_01 0x01
|
||||
#define W1_FAMILY_SMEM_81 0x81
|
||||
#define W1_THERM_DS18S20 0x10
|
||||
#define W1_FAMILY_DS28E04 0x1C
|
||||
#define W1_COUNTER_DS2423 0x1D
|
||||
#define W1_THERM_DS1822 0x22
|
||||
#define W1_EEPROM_DS2433 0x23
|
||||
|
||||
Loading…
Reference in New Issue
Block a user