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Release 4.10 drivers/hwmon/g760a.c

Directory: drivers/hwmon
/*
 * 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/product/datasheet/EDS-760A.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>


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 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))


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

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herbert valerio riedelherbert valerio riedel4095.24%150.00%
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Total42100.00%2100.00%

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

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

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/* * sysfs attributes */
static struct g760a_data *g760a_update_client(struct device *dev) { struct g760a_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->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; }

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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); }

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herbert valerio riedelherbert valerio riedel90100.00%1100.00%
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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); }

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herbert valerio riedelherbert valerio riedel55100.00%1100.00%
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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)); }

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herbert valerio riedelherbert valerio riedel45100.00%1100.00%
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static ssize_t set_pwm(struct device *dev, struct device_attribute *da, const char *buf, size_t count) { struct g760a_data *data = g760a_update_client(dev); struct i2c_client *client = data->client; unsigned long val; if (kstrtoul(buf, 10, &val)) return -EINVAL; mutex_lock(&data->update_lock); data->set_cnt = PWM_TO_CNT(clamp_val(val, 0, 255)); g760a_write_value(client, G760A_REG_SET_CNT, data->set_cnt); mutex_unlock(&data->update_lock); return count; }

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herbert valerio riedelherbert valerio riedel9990.83%125.00%
axel linaxel lin87.34%125.00%
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guenter roeckguenter roeck10.92%125.00%
Total109100.00%4100.00%

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_attrs[] = { &dev_attr_pwm1.attr, &dev_attr_fan1_input.attr, &dev_attr_fan1_alarm.attr, NULL }; ATTRIBUTE_GROUPS(g760a); /* * new-style driver model code */
static int g760a_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct g760a_data *data; struct device *hwmon_dev; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) return -EIO; data = devm_kzalloc(dev, sizeof(struct g760a_data), GFP_KERNEL); if (!data) return -ENOMEM; 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; hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, data, g760a_groups); return PTR_ERR_OR_ZERO(hwmon_dev); }

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herbert valerio riedelherbert valerio riedel10281.60%133.33%
axel linaxel lin2016.00%133.33%
guenter roeckguenter roeck32.40%133.33%
Total125100.00%3100.00%

static const struct i2c_device_id g760a_id[] = { { "g760a", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, g760a_id); static struct i2c_driver g760a_driver = { .driver = { .name = "g760a", }, .probe = g760a_probe, .id_table = g760a_id, }; module_i2c_driver(g760a_driver); MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>"); MODULE_DESCRIPTION("GMT G760A driver"); MODULE_LICENSE("GPL");

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herbert valerio riedelherbert valerio riedel81388.66%111.11%
axel linaxel lin9310.14%333.33%
guenter roeckguenter roeck80.87%333.33%
jean delvarejean delvare20.22%111.11%
frans meulenbroeksfrans meulenbroeks10.11%111.11%
Total917100.00%9100.00%
Directory: drivers/hwmon
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