drivers/hwmon/g760a.c - kernel/msm-4.9 - Gitiles

 /*
     g760a - Driver for the Global Mixed-mode Technology Inc. G760A
             fan speed PWM controller chip

     Copyright (C) 2007  Herbert Valerio Riedel <hvr@gnu.org>

     Complete datasheet is available at GMT's website:
       http://www.gmt.com.tw/datasheet/g760a.pdf

     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.
 */

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

 static const struct i2c_device_id g760a_id[] = {
 	{ "g760a", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, g760a_id);

 enum g760a_regs {
 	G760A_REG_SET_CNT = 0x00,
 	G760A_REG_ACT_CNT = 0x01,
 	G760A_REG_FAN_STA = 0x02
 };

 #define G760A_REG_FAN_STA_RPM_OFF 0x1 /* +/-20% off */
 #define G760A_REG_FAN_STA_RPM_LOW 0x2 /* below 1920rpm */

 /* register data is read (and cached) at most once per second */
 #define G760A_UPDATE_INTERVAL (HZ)

 struct g760a_data {
 	struct i2c_client *client;
 	struct device *hwmon_dev;
 	struct mutex update_lock;

 	/* board specific parameters */
 	u32 clk; /* default 32kHz */
 	u16 fan_div; /* default P=2 */

 	/* g760a register cache */
 	unsigned int valid:1;
 	unsigned long last_updated; /* In jiffies */

 	u8 set_cnt; /* PWM (period) count number; 0xff stops fan */
 	u8 act_cnt; /*   formula: cnt = (CLK * 30)/(rpm * P) */
 	u8 fan_sta; /* bit 0: set when actual fan speed more than 20%
 		     *   outside requested fan speed
 		     * bit 1: set when fan speed below 1920 rpm */
 };

 #define G760A_DEFAULT_CLK 32768
 #define G760A_DEFAULT_FAN_DIV 2

 #define PWM_FROM_CNT(cnt)	(0xff-(cnt))
 #define PWM_TO_CNT(pwm)		(0xff-(pwm))

 unsigned int rpm_from_cnt(u8 val, u32 clk, u16 div)
 {
 	return ((val == 0x00) ? 0 : ((clk*30)/(val*div)));
 }

 /* new-style driver model */
 static int g760a_probe(struct i2c_client *client,
 			const struct i2c_device_id *id);
 static int g760a_remove(struct i2c_client *client);

 static struct i2c_driver g760a_driver = {
 	.driver = {
 		.name	= "g760a",
 	},
 	.probe	  = g760a_probe,
 	.remove	  = g760a_remove,
 	.id_table = g760a_id,
 };

 /* read/write wrappers */
 static int g760a_read_value(struct i2c_client *client, enum g760a_regs reg)
 {
 	return i2c_smbus_read_byte_data(client, reg);
 }

 static int g760a_write_value(struct i2c_client *client, enum g760a_regs reg,
 			     u16 value)
 {
 	return i2c_smbus_write_byte_data(client, reg, value);
 }

 /****************************************************************************
  * sysfs attributes
  */

 static struct g760a_data *g760a_update_client(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct g760a_data *data = i2c_get_clientdata(client);

 	mutex_lock(&data->update_lock);

 	if (time_after(jiffies, data->last_updated + G760A_UPDATE_INTERVAL)
 	    || !data->valid) {
 		dev_dbg(&client->dev, "Starting g760a update\n");

 		data->set_cnt = g760a_read_value(client, G760A_REG_SET_CNT);
 		data->act_cnt = g760a_read_value(client, G760A_REG_ACT_CNT);
 		data->fan_sta = g760a_read_value(client, G760A_REG_FAN_STA);

 		data->last_updated = jiffies;
 		data->valid = 1;
 	}

 	mutex_unlock(&data->update_lock);

 	return data;
 }

 static ssize_t show_fan(struct device *dev, struct device_attribute *da,
 			char *buf)
 {
 	struct g760a_data *data = g760a_update_client(dev);
 	unsigned int rpm = 0;

 	mutex_lock(&data->update_lock);
 	if (!(data->fan_sta & G760A_REG_FAN_STA_RPM_LOW))
 		rpm = rpm_from_cnt(data->act_cnt, data->clk, data->fan_div);
 	mutex_unlock(&data->update_lock);

 	return sprintf(buf, "%d\n", rpm);
 }

 static ssize_t show_fan_alarm(struct device *dev, struct device_attribute *da,
 			      char *buf)
 {
 	struct g760a_data *data = g760a_update_client(dev);

 	int fan_alarm = (data->fan_sta & G760A_REG_FAN_STA_RPM_OFF) ? 1 : 0;

 	return sprintf(buf, "%d\n", fan_alarm);
 }

 static ssize_t get_pwm(struct device *dev, struct device_attribute *da,
 		       char *buf)
 {
 	struct g760a_data *data = g760a_update_client(dev);

 	return sprintf(buf, "%d\n", PWM_FROM_CNT(data->set_cnt));
 }

 static ssize_t set_pwm(struct device *dev, struct device_attribute *da,
 		       const char *buf, size_t count)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct g760a_data *data = g760a_update_client(dev);
 	unsigned long val;

 	if (strict_strtoul(buf, 10, &val))
 		return -EINVAL;

 	mutex_lock(&data->update_lock);
 	data->set_cnt = PWM_TO_CNT(SENSORS_LIMIT(val, 0, 255));
 	g760a_write_value(client, G760A_REG_SET_CNT, data->set_cnt);
 	mutex_unlock(&data->update_lock);

 	return count;
 }

 static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm);
 static DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL);
 static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL);

 static struct attribute *g760a_attributes[] = {
 	&dev_attr_pwm1.attr,
 	&dev_attr_fan1_input.attr,
 	&dev_attr_fan1_alarm.attr,
 	NULL
 };

 static const struct attribute_group g760a_group = {
 	.attrs = g760a_attributes,
 };

 /****************************************************************************
  * new-style driver model code
  */

 static int g760a_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	struct g760a_data *data;
 	int err;

 	if (!i2c_check_functionality(client->adapter,
 				     I2C_FUNC_SMBUS_BYTE_DATA))
 		return -EIO;

 	data = kzalloc(sizeof(struct g760a_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	i2c_set_clientdata(client, data);

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

 	/* setup default configuration for now */
 	data->fan_div = G760A_DEFAULT_FAN_DIV;
 	data->clk = G760A_DEFAULT_CLK;

 	/* Register sysfs hooks */
 	err = sysfs_create_group(&client->dev.kobj, &g760a_group);
 	if (err)
 		goto error_sysfs_create_group;

 	data->hwmon_dev = hwmon_device_register(&client->dev);
 	if (IS_ERR(data->hwmon_dev)) {
 		err = PTR_ERR(data->hwmon_dev);
 		goto error_hwmon_device_register;
 	}

 	return 0;

 error_hwmon_device_register:
 	sysfs_remove_group(&client->dev.kobj, &g760a_group);
 error_sysfs_create_group:
 	kfree(data);
 	i2c_set_clientdata(client, NULL);

 	return err;
 }

 static int g760a_remove(struct i2c_client *client)
 {
 	struct g760a_data *data = i2c_get_clientdata(client);
 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &g760a_group);
 	kfree(data);
 	i2c_set_clientdata(client, NULL);

 	return 0;
 }

 /* module management */

 static int __init g760a_init(void)
 {
 	return i2c_add_driver(&g760a_driver);
 }

 static void __exit g760a_exit(void)
 {
 	i2c_del_driver(&g760a_driver);
 }

 MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
 MODULE_DESCRIPTION("GMT G760A driver");
 MODULE_LICENSE("GPL");

 module_init(g760a_init);
 module_exit(g760a_exit);
	/*
	g760a - Driver for the Global Mixed-mode Technology Inc. G760A
	fan speed PWM controller chip

	Copyright (C) 2007 Herbert Valerio Riedel <hvr@gnu.org>

	Complete datasheet is available at GMT's website:
	http://www.gmt.com.tw/datasheet/g760a.pdf

	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.
	*/

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

	static const struct i2c_device_id g760a_id[] = {
	{ "g760a", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, g760a_id);

	enum g760a_regs {
	G760A_REG_SET_CNT = 0x00,
	G760A_REG_ACT_CNT = 0x01,
	G760A_REG_FAN_STA = 0x02
	};

	#define G760A_REG_FAN_STA_RPM_OFF 0x1 /* +/-20% off */
	#define G760A_REG_FAN_STA_RPM_LOW 0x2 /* below 1920rpm */

	/* register data is read (and cached) at most once per second */
	#define G760A_UPDATE_INTERVAL (HZ)

	struct g760a_data {
	struct i2c_client *client;
	struct device *hwmon_dev;
	struct mutex update_lock;

	/* board specific parameters */
	u32 clk; /* default 32kHz */
	u16 fan_div; /* default P=2 */

	/* g760a register cache */
	unsigned int valid:1;
	unsigned long last_updated; /* In jiffies */

	u8 set_cnt; /* PWM (period) count number; 0xff stops fan */
	u8 act_cnt; /* formula: cnt = (CLK * 30)/(rpm * P) */
	u8 fan_sta; /* bit 0: set when actual fan speed more than 20%
	* outside requested fan speed
	* bit 1: set when fan speed below 1920 rpm */
	};

	#define G760A_DEFAULT_CLK 32768
	#define G760A_DEFAULT_FAN_DIV 2

	#define PWM_FROM_CNT(cnt) (0xff-(cnt))
	#define PWM_TO_CNT(pwm) (0xff-(pwm))

	unsigned int rpm_from_cnt(u8 val, u32 clk, u16 div)
	{
	return ((val == 0x00) ? 0 : ((clk30)/(valdiv)));
	}

	/* new-style driver model */
	static int g760a_probe(struct i2c_client *client,
	const struct i2c_device_id *id);
	static int g760a_remove(struct i2c_client *client);

	static struct i2c_driver g760a_driver = {
	.driver = {
	.name = "g760a",
	},
	.probe = g760a_probe,
	.remove = g760a_remove,
	.id_table = g760a_id,
	};

	/* read/write wrappers */
	static int g760a_read_value(struct i2c_client *client, enum g760a_regs reg)
	{
	return i2c_smbus_read_byte_data(client, reg);
	}

	static int g760a_write_value(struct i2c_client *client, enum g760a_regs reg,
	u16 value)
	{
	return i2c_smbus_write_byte_data(client, reg, value);
	}

	/****************************************************************************
	* sysfs attributes
	*/

	static struct g760a_data g760a_update_client(struct device dev)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct g760a_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + G760A_UPDATE_INTERVAL)
	\|\| !data->valid) {
	dev_dbg(&client->dev, "Starting g760a update\n");

	data->set_cnt = g760a_read_value(client, G760A_REG_SET_CNT);
	data->act_cnt = g760a_read_value(client, G760A_REG_ACT_CNT);
	data->fan_sta = g760a_read_value(client, G760A_REG_FAN_STA);

	data->last_updated = jiffies;
	data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
	}

	static ssize_t show_fan(struct device dev, struct device_attribute da,
	char *buf)
	{
	struct g760a_data *data = g760a_update_client(dev);
	unsigned int rpm = 0;

	mutex_lock(&data->update_lock);
	if (!(data->fan_sta & G760A_REG_FAN_STA_RPM_LOW))
	rpm = rpm_from_cnt(data->act_cnt, data->clk, data->fan_div);
	mutex_unlock(&data->update_lock);

	return sprintf(buf, "%d\n", rpm);
	}

	static ssize_t show_fan_alarm(struct device dev, struct device_attribute da,
	char *buf)
	{
	struct g760a_data *data = g760a_update_client(dev);

	int fan_alarm = (data->fan_sta & G760A_REG_FAN_STA_RPM_OFF) ? 1 : 0;

	return sprintf(buf, "%d\n", fan_alarm);
	}

	static ssize_t get_pwm(struct device dev, struct device_attribute da,
	char *buf)
	{
	struct g760a_data *data = g760a_update_client(dev);

	return sprintf(buf, "%d\n", PWM_FROM_CNT(data->set_cnt));
	}

	static ssize_t set_pwm(struct device dev, struct device_attribute da,
	const char *buf, size_t count)
	{
	struct i2c_client *client = to_i2c_client(dev);
	struct g760a_data *data = g760a_update_client(dev);
	unsigned long val;

	if (strict_strtoul(buf, 10, &val))
	return -EINVAL;

	mutex_lock(&data->update_lock);
	data->set_cnt = PWM_TO_CNT(SENSORS_LIMIT(val, 0, 255));
	g760a_write_value(client, G760A_REG_SET_CNT, data->set_cnt);
	mutex_unlock(&data->update_lock);

	return count;
	}

	static DEVICE_ATTR(pwm1, S_IWUSR \| S_IRUGO, get_pwm, set_pwm);
	static DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL);
	static DEVICE_ATTR(fan1_alarm, S_IRUGO, show_fan_alarm, NULL);

	static struct attribute *g760a_attributes[] = {
	&dev_attr_pwm1.attr,
	&dev_attr_fan1_input.attr,
	&dev_attr_fan1_alarm.attr,
	NULL
	};

	static const struct attribute_group g760a_group = {
	.attrs = g760a_attributes,
	};

	/****************************************************************************
	* new-style driver model code
	*/

	static int g760a_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct g760a_data *data;
	int err;

	if (!i2c_check_functionality(client->adapter,
	I2C_FUNC_SMBUS_BYTE_DATA))
	return -EIO;

	data = kzalloc(sizeof(struct g760a_data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	i2c_set_clientdata(client, data);

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

	/* setup default configuration for now */
	data->fan_div = G760A_DEFAULT_FAN_DIV;
	data->clk = G760A_DEFAULT_CLK;

	/* Register sysfs hooks */
	err = sysfs_create_group(&client->dev.kobj, &g760a_group);
	if (err)
	goto error_sysfs_create_group;

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
	err = PTR_ERR(data->hwmon_dev);
	goto error_hwmon_device_register;
	}

	return 0;

	error_hwmon_device_register:
	sysfs_remove_group(&client->dev.kobj, &g760a_group);
	error_sysfs_create_group:
	kfree(data);
	i2c_set_clientdata(client, NULL);

	return err;
	}

	static int g760a_remove(struct i2c_client *client)
	{
	struct g760a_data *data = i2c_get_clientdata(client);
	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &g760a_group);
	kfree(data);
	i2c_set_clientdata(client, NULL);

	return 0;
	}

	/* module management */

	static int __init g760a_init(void)
	{
	return i2c_add_driver(&g760a_driver);
	}

	static void __exit g760a_exit(void)
	{
	i2c_del_driver(&g760a_driver);
	}

	MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>");
	MODULE_DESCRIPTION("GMT G760A driver");
	MODULE_LICENSE("GPL");

	module_init(g760a_init);
	module_exit(g760a_exit);