drivers/hwmon/atxp1.c - linux - Git at Google

 /*
  * atxp1.c - kernel module for setting CPU VID and general purpose
  *	     I/Os using the Attansic ATXP1 chip.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * The ATXP1 can reside on I2C addresses 0x37 or 0x4e. The chip is
  * not auto-detected by the driver and must be instantiated explicitly.
  * See Documentation/i2c/instantiating-devices for more information.
  */

 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/jiffies.h>
 #include <linux/i2c.h>
 #include <linux/hwmon.h>
 #include <linux/hwmon-vid.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
 #include <linux/sysfs.h>
 #include <linux/slab.h>

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("System voltages control via Attansic ATXP1");
 MODULE_VERSION("0.6.3");
 MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");

 #define ATXP1_VID	0x00
 #define ATXP1_CVID	0x01
 #define ATXP1_GPIO1	0x06
 #define ATXP1_GPIO2	0x0a
 #define ATXP1_VIDENA	0x20
 #define ATXP1_VIDMASK	0x1f
 #define ATXP1_GPIO1MASK	0x0f

 struct atxp1_data {
 	struct i2c_client *client;
 	struct mutex update_lock;
 	unsigned long last_updated;
 	u8 valid;
 	struct {
 		u8 vid;		/* VID output register */
 		u8 cpu_vid; /* VID input from CPU */
 		u8 gpio1;   /* General purpose I/O register 1 */
 		u8 gpio2;   /* General purpose I/O register 2 */
 	} reg;
 	u8 vrm;			/* Detected CPU VRM */
 };

 static struct atxp1_data *atxp1_update_device(struct device *dev)
 {
 	struct atxp1_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;

 	mutex_lock(&data->update_lock);

 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {

 		/* Update local register data */
 		data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
 		data->reg.cpu_vid = i2c_smbus_read_byte_data(client,
 							     ATXP1_CVID);
 		data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
 		data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);

 		data->valid = 1;
 	}

 	mutex_unlock(&data->update_lock);

 	return data;
 }

 /* sys file functions for cpu0_vid */
 static ssize_t atxp1_showvcore(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	int size;
 	struct atxp1_data *data;

 	data = atxp1_update_device(dev);

 	size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK,
 						 data->vrm));

 	return size;
 }

 static ssize_t atxp1_storevcore(struct device *dev,
 				struct device_attribute *attr,
 				const char *buf, size_t count)
 {
 	struct atxp1_data *data = atxp1_update_device(dev);
 	struct i2c_client *client = data->client;
 	int vid, cvid;
 	unsigned long vcore;
 	int err;

 	err = kstrtoul(buf, 10, &vcore);
 	if (err)
 		return err;

 	vcore /= 25;
 	vcore *= 25;

 	/* Calculate VID */
 	vid = vid_to_reg(vcore, data->vrm);
 	if (vid < 0) {
 		dev_err(dev, "VID calculation failed.\n");
 		return vid;
 	}

 	/*
 	 * If output enabled, use control register value.
 	 * Otherwise original CPU VID
 	 */
 	if (data->reg.vid & ATXP1_VIDENA)
 		cvid = data->reg.vid & ATXP1_VIDMASK;
 	else
 		cvid = data->reg.cpu_vid;

 	/* Nothing changed, aborting */
 	if (vid == cvid)
 		return count;

 	dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid);

 	/* Write every 25 mV step to increase stability */
 	if (cvid > vid) {
 		for (; cvid >= vid; cvid--)
 			i2c_smbus_write_byte_data(client,
 						ATXP1_VID, cvid | ATXP1_VIDENA);
 	} else {
 		for (; cvid <= vid; cvid++)
 			i2c_smbus_write_byte_data(client,
 						ATXP1_VID, cvid | ATXP1_VIDENA);
 	}

 	data->valid = 0;

 	return count;
 }

 /*
  * CPU core reference voltage
  * unit: millivolt
  */
 static DEVICE_ATTR(cpu0_vid, S_IRUGO | S_IWUSR, atxp1_showvcore,
 		   atxp1_storevcore);

 /* sys file functions for GPIO1 */
 static ssize_t atxp1_showgpio1(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	int size;
 	struct atxp1_data *data;

 	data = atxp1_update_device(dev);

 	size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);

 	return size;
 }

 static ssize_t atxp1_storegpio1(struct device *dev,
 				struct device_attribute *attr, const char *buf,
 				size_t count)
 {
 	struct atxp1_data *data = atxp1_update_device(dev);
 	struct i2c_client *client = data->client;
 	unsigned long value;
 	int err;

 	err = kstrtoul(buf, 16, &value);
 	if (err)
 		return err;

 	value &= ATXP1_GPIO1MASK;

 	if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
 		dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);

 		i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);

 		data->valid = 0;
 	}

 	return count;
 }

 /*
  * GPIO1 data register
  * unit: Four bit as hex (e.g. 0x0f)
  */
 static DEVICE_ATTR(gpio1, S_IRUGO | S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);

 /* sys file functions for GPIO2 */
 static ssize_t atxp1_showgpio2(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	int size;
 	struct atxp1_data *data;

 	data = atxp1_update_device(dev);

 	size = sprintf(buf, "0x%02x\n", data->reg.gpio2);

 	return size;
 }

 static ssize_t atxp1_storegpio2(struct device *dev,
 				struct device_attribute *attr,
 				const char *buf, size_t count)
 {
 	struct atxp1_data *data = atxp1_update_device(dev);
 	struct i2c_client *client = data->client;
 	unsigned long value;
 	int err;

 	err = kstrtoul(buf, 16, &value);
 	if (err)
 		return err;
 	value &= 0xff;

 	if (value != data->reg.gpio2) {
 		dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);

 		i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);

 		data->valid = 0;
 	}

 	return count;
 }

 /*
  * GPIO2 data register
  * unit: Eight bit as hex (e.g. 0xff)
  */
 static DEVICE_ATTR(gpio2, S_IRUGO | S_IWUSR, atxp1_showgpio2, atxp1_storegpio2);

 static struct attribute *atxp1_attrs[] = {
 	&dev_attr_gpio1.attr,
 	&dev_attr_gpio2.attr,
 	&dev_attr_cpu0_vid.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(atxp1);

 static int atxp1_probe(struct i2c_client *client,
 		       const struct i2c_device_id *id)
 {
 	struct device *dev = &client->dev;
 	struct atxp1_data *data;
 	struct device *hwmon_dev;

 	data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	/* Get VRM */
 	data->vrm = vid_which_vrm();
 	if (data->vrm != 90 && data->vrm != 91) {
 		dev_err(dev, "atxp1: Not supporting VRM %d.%d\n",
 			data->vrm / 10, data->vrm % 10);
 		return -ENODEV;
 	}

 	data->client = client;
 	mutex_init(&data->update_lock);

 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 							   data,
 							   atxp1_groups);
 	if (IS_ERR(hwmon_dev))
 		return PTR_ERR(hwmon_dev);

 	dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10);

 	return 0;
 };

 static const struct i2c_device_id atxp1_id[] = {
 	{ "atxp1", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, atxp1_id);

 static struct i2c_driver atxp1_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.driver = {
 		.name	= "atxp1",
 	},
 	.probe		= atxp1_probe,
 	.id_table	= atxp1_id,
 };

 module_i2c_driver(atxp1_driver);
	/*
	* atxp1.c - kernel module for setting CPU VID and general purpose
	* I/Os using the Attansic ATXP1 chip.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* The ATXP1 can reside on I2C addresses 0x37 or 0x4e. The chip is
	* not auto-detected by the driver and must be instantiated explicitly.
	* See Documentation/i2c/instantiating-devices for more information.
	*/

	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/jiffies.h>
	#include <linux/i2c.h>
	#include <linux/hwmon.h>
	#include <linux/hwmon-vid.h>
	#include <linux/err.h>
	#include <linux/mutex.h>
	#include <linux/sysfs.h>
	#include <linux/slab.h>

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("System voltages control via Attansic ATXP1");
	MODULE_VERSION("0.6.3");
	MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");

	#define ATXP1_VID 0x00
	#define ATXP1_CVID 0x01
	#define ATXP1_GPIO1 0x06
	#define ATXP1_GPIO2 0x0a
	#define ATXP1_VIDENA 0x20
	#define ATXP1_VIDMASK 0x1f
	#define ATXP1_GPIO1MASK 0x0f

	struct atxp1_data {
	struct i2c_client *client;
	struct mutex update_lock;
	unsigned long last_updated;
	u8 valid;
	struct {
	u8 vid; /* VID output register */
	u8 cpu_vid; /* VID input from CPU */
	u8 gpio1; /* General purpose I/O register 1 */
	u8 gpio2; /* General purpose I/O register 2 */
	} reg;
	u8 vrm; /* Detected CPU VRM */
	};

	static struct atxp1_data atxp1_update_device(struct device dev)
	{
	struct atxp1_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ) \|\| !data->valid) {

	/* Update local register data */
	data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
	data->reg.cpu_vid = i2c_smbus_read_byte_data(client,
	ATXP1_CVID);
	data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
	data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);

	data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
	}

	/* sys file functions for cpu0_vid */
	static ssize_t atxp1_showvcore(struct device *dev,
	struct device_attribute attr, char buf)
	{
	int size;
	struct atxp1_data *data;

	data = atxp1_update_device(dev);

	size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK,
	data->vrm));

	return size;
	}

	static ssize_t atxp1_storevcore(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct atxp1_data *data = atxp1_update_device(dev);
	struct i2c_client *client = data->client;
	int vid, cvid;
	unsigned long vcore;
	int err;

	err = kstrtoul(buf, 10, &vcore);
	if (err)
	return err;

	vcore /= 25;
	vcore *= 25;

	/* Calculate VID */
	vid = vid_to_reg(vcore, data->vrm);
	if (vid < 0) {
	dev_err(dev, "VID calculation failed.\n");
	return vid;
	}

	/*
	* If output enabled, use control register value.
	* Otherwise original CPU VID
	*/
	if (data->reg.vid & ATXP1_VIDENA)
	cvid = data->reg.vid & ATXP1_VIDMASK;
	else
	cvid = data->reg.cpu_vid;

	/* Nothing changed, aborting */
	if (vid == cvid)
	return count;

	dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid);

	/* Write every 25 mV step to increase stability */
	if (cvid > vid) {
	for (; cvid >= vid; cvid--)
	i2c_smbus_write_byte_data(client,
	ATXP1_VID, cvid \| ATXP1_VIDENA);
	} else {
	for (; cvid <= vid; cvid++)
	i2c_smbus_write_byte_data(client,
	ATXP1_VID, cvid \| ATXP1_VIDENA);
	}

	data->valid = 0;

	return count;
	}

	/*
	* CPU core reference voltage
	* unit: millivolt
	*/
	static DEVICE_ATTR(cpu0_vid, S_IRUGO \| S_IWUSR, atxp1_showvcore,
	atxp1_storevcore);

	/* sys file functions for GPIO1 */
	static ssize_t atxp1_showgpio1(struct device *dev,
	struct device_attribute attr, char buf)
	{
	int size;
	struct atxp1_data *data;

	data = atxp1_update_device(dev);

	size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);

	return size;
	}

	static ssize_t atxp1_storegpio1(struct device *dev,
	struct device_attribute attr, const char buf,
	size_t count)
	{
	struct atxp1_data *data = atxp1_update_device(dev);
	struct i2c_client *client = data->client;
	unsigned long value;
	int err;

	err = kstrtoul(buf, 16, &value);
	if (err)
	return err;

	value &= ATXP1_GPIO1MASK;

	if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
	dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);

	i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);

	data->valid = 0;
	}

	return count;
	}

	/*
	* GPIO1 data register
	* unit: Four bit as hex (e.g. 0x0f)
	*/
	static DEVICE_ATTR(gpio1, S_IRUGO \| S_IWUSR, atxp1_showgpio1, atxp1_storegpio1);

	/* sys file functions for GPIO2 */
	static ssize_t atxp1_showgpio2(struct device *dev,
	struct device_attribute attr, char buf)
	{
	int size;
	struct atxp1_data *data;

	data = atxp1_update_device(dev);

	size = sprintf(buf, "0x%02x\n", data->reg.gpio2);

	return size;
	}

	static ssize_t atxp1_storegpio2(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct atxp1_data *data = atxp1_update_device(dev);
	struct i2c_client *client = data->client;
	unsigned long value;
	int err;

	err = kstrtoul(buf, 16, &value);
	if (err)
	return err;
	value &= 0xff;

	if (value != data->reg.gpio2) {
	dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);

	i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);

	data->valid = 0;
	}

	return count;
	}

	/*
	* GPIO2 data register
	* unit: Eight bit as hex (e.g. 0xff)
	*/
	static DEVICE_ATTR(gpio2, S_IRUGO \| S_IWUSR, atxp1_showgpio2, atxp1_storegpio2);

	static struct attribute *atxp1_attrs[] = {
	&dev_attr_gpio1.attr,
	&dev_attr_gpio2.attr,
	&dev_attr_cpu0_vid.attr,
	NULL
	};
	ATTRIBUTE_GROUPS(atxp1);

	static int atxp1_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct device *dev = &client->dev;
	struct atxp1_data *data;
	struct device *hwmon_dev;

	data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	/* Get VRM */
	data->vrm = vid_which_vrm();
	if (data->vrm != 90 && data->vrm != 91) {
	dev_err(dev, "atxp1: Not supporting VRM %d.%d\n",
	data->vrm / 10, data->vrm % 10);
	return -ENODEV;
	}

	data->client = client;
	mutex_init(&data->update_lock);

	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
	data,
	atxp1_groups);
	if (IS_ERR(hwmon_dev))
	return PTR_ERR(hwmon_dev);

	dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10);

	return 0;
	};

	static const struct i2c_device_id atxp1_id[] = {
	{ "atxp1", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, atxp1_id);

	static struct i2c_driver atxp1_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "atxp1",
	},
	.probe = atxp1_probe,
	.id_table = atxp1_id,
	};

	module_i2c_driver(atxp1_driver);