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ccf988b66d
Convert each file at I2C subsystem, renaming them to .rst and adding to the driver-api book. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
296 lines
6.5 KiB
C
296 lines
6.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* atxp1.c - kernel module for setting CPU VID and general purpose
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* I/Os using the Attansic ATXP1 chip.
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*
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* The ATXP1 can reside on I2C addresses 0x37 or 0x4e. The chip is
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* not auto-detected by the driver and must be instantiated explicitly.
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* See Documentation/i2c/instantiating-devices.rst for more information.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/jiffies.h>
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#include <linux/i2c.h>
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#include <linux/hwmon.h>
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#include <linux/hwmon-vid.h>
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/sysfs.h>
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#include <linux/slab.h>
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("System voltages control via Attansic ATXP1");
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MODULE_VERSION("0.6.3");
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MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");
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#define ATXP1_VID 0x00
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#define ATXP1_CVID 0x01
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#define ATXP1_GPIO1 0x06
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#define ATXP1_GPIO2 0x0a
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#define ATXP1_VIDENA 0x20
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#define ATXP1_VIDMASK 0x1f
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#define ATXP1_GPIO1MASK 0x0f
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struct atxp1_data {
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struct i2c_client *client;
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struct mutex update_lock;
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unsigned long last_updated;
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u8 valid;
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struct {
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u8 vid; /* VID output register */
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u8 cpu_vid; /* VID input from CPU */
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u8 gpio1; /* General purpose I/O register 1 */
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u8 gpio2; /* General purpose I/O register 2 */
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} reg;
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u8 vrm; /* Detected CPU VRM */
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};
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static struct atxp1_data *atxp1_update_device(struct device *dev)
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{
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struct atxp1_data *data = dev_get_drvdata(dev);
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struct i2c_client *client = data->client;
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mutex_lock(&data->update_lock);
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if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
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/* Update local register data */
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data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
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data->reg.cpu_vid = i2c_smbus_read_byte_data(client,
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ATXP1_CVID);
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data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
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data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
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data->valid = 1;
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}
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mutex_unlock(&data->update_lock);
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return data;
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}
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/* sys file functions for cpu0_vid */
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static ssize_t cpu0_vid_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int size;
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struct atxp1_data *data;
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data = atxp1_update_device(dev);
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size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK,
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data->vrm));
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return size;
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}
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static ssize_t cpu0_vid_store(struct device *dev,
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struct device_attribute *attr, const char *buf,
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size_t count)
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{
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struct atxp1_data *data = atxp1_update_device(dev);
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struct i2c_client *client = data->client;
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int vid, cvid;
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unsigned long vcore;
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int err;
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err = kstrtoul(buf, 10, &vcore);
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if (err)
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return err;
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vcore /= 25;
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vcore *= 25;
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/* Calculate VID */
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vid = vid_to_reg(vcore, data->vrm);
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if (vid < 0) {
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dev_err(dev, "VID calculation failed.\n");
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return vid;
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}
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/*
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* If output enabled, use control register value.
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* Otherwise original CPU VID
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*/
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if (data->reg.vid & ATXP1_VIDENA)
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cvid = data->reg.vid & ATXP1_VIDMASK;
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else
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cvid = data->reg.cpu_vid;
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/* Nothing changed, aborting */
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if (vid == cvid)
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return count;
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dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid);
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/* Write every 25 mV step to increase stability */
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if (cvid > vid) {
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for (; cvid >= vid; cvid--)
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i2c_smbus_write_byte_data(client,
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ATXP1_VID, cvid | ATXP1_VIDENA);
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} else {
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for (; cvid <= vid; cvid++)
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i2c_smbus_write_byte_data(client,
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ATXP1_VID, cvid | ATXP1_VIDENA);
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}
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data->valid = 0;
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return count;
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}
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/*
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* CPU core reference voltage
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* unit: millivolt
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*/
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static DEVICE_ATTR_RW(cpu0_vid);
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/* sys file functions for GPIO1 */
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static ssize_t gpio1_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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int size;
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struct atxp1_data *data;
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data = atxp1_update_device(dev);
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size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
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return size;
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}
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static ssize_t gpio1_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct atxp1_data *data = atxp1_update_device(dev);
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struct i2c_client *client = data->client;
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unsigned long value;
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int err;
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err = kstrtoul(buf, 16, &value);
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if (err)
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return err;
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value &= ATXP1_GPIO1MASK;
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if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
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dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
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i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
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data->valid = 0;
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}
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return count;
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}
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/*
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* GPIO1 data register
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* unit: Four bit as hex (e.g. 0x0f)
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*/
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static DEVICE_ATTR_RW(gpio1);
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/* sys file functions for GPIO2 */
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static ssize_t gpio2_show(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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int size;
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struct atxp1_data *data;
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data = atxp1_update_device(dev);
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size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
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return size;
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}
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static ssize_t gpio2_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct atxp1_data *data = atxp1_update_device(dev);
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struct i2c_client *client = data->client;
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unsigned long value;
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int err;
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err = kstrtoul(buf, 16, &value);
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if (err)
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return err;
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value &= 0xff;
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if (value != data->reg.gpio2) {
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dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
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i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
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data->valid = 0;
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}
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return count;
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}
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/*
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* GPIO2 data register
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* unit: Eight bit as hex (e.g. 0xff)
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*/
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static DEVICE_ATTR_RW(gpio2);
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static struct attribute *atxp1_attrs[] = {
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&dev_attr_gpio1.attr,
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&dev_attr_gpio2.attr,
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&dev_attr_cpu0_vid.attr,
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NULL
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};
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ATTRIBUTE_GROUPS(atxp1);
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static int atxp1_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct device *dev = &client->dev;
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struct atxp1_data *data;
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struct device *hwmon_dev;
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data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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/* Get VRM */
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data->vrm = vid_which_vrm();
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if (data->vrm != 90 && data->vrm != 91) {
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dev_err(dev, "atxp1: Not supporting VRM %d.%d\n",
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data->vrm / 10, data->vrm % 10);
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return -ENODEV;
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}
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data->client = client;
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mutex_init(&data->update_lock);
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hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
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data,
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atxp1_groups);
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if (IS_ERR(hwmon_dev))
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return PTR_ERR(hwmon_dev);
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dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10);
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return 0;
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};
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static const struct i2c_device_id atxp1_id[] = {
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{ "atxp1", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, atxp1_id);
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static struct i2c_driver atxp1_driver = {
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.class = I2C_CLASS_HWMON,
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.driver = {
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.name = "atxp1",
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},
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.probe = atxp1_probe,
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.id_table = atxp1_id,
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};
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module_i2c_driver(atxp1_driver);
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