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Release 4.14 drivers/hwmon/lm77.c

Directory: drivers/hwmon
/*
 * lm77.c - Part of lm_sensors, Linux kernel modules for hardware
 *          monitoring
 *
 * Copyright (c) 2004  Andras BALI <drewie@freemail.hu>
 *
 * Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>.  The LM77
 * is a temperature sensor and thermal window comparator with 0.5 deg
 * resolution made by National Semiconductor.  Complete datasheet can be
 * obtained at their site:
 *      http://www.national.com/pf/LM/LM77.html
 *
 * 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.
 */

#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>

/* Addresses to scan */

static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
						I2C_CLIENT_END };

/* The LM77 registers */

#define LM77_REG_TEMP		0x00

#define LM77_REG_CONF		0x01

#define LM77_REG_TEMP_HYST	0x02

#define LM77_REG_TEMP_CRIT	0x03

#define LM77_REG_TEMP_MIN	0x04

#define LM77_REG_TEMP_MAX	0x05


enum temp_index {
	
t_input = 0,
	
t_crit,
	
t_min,
	
t_max,
	
t_hyst,
	
t_num_temp
};


static const u8 temp_regs[t_num_temp] = {
	[t_input] = LM77_REG_TEMP,
	[t_min] = LM77_REG_TEMP_MIN,
	[t_max] = LM77_REG_TEMP_MAX,
	[t_crit] = LM77_REG_TEMP_CRIT,
	[t_hyst] = LM77_REG_TEMP_HYST,
};

/* Each client has this additional data */

struct lm77_data {
	
struct i2c_client	*client;
	
struct mutex		update_lock;
	
char			valid;
	
unsigned long		last_updated;	/* In jiffies */
	
int			temp[t_num_temp]; /* index using temp_index */
	
u8			alarms;
};

/* straight from the datasheet */

#define LM77_TEMP_MIN (-55000)

#define LM77_TEMP_MAX 125000

/*
 * In the temperature registers, the low 3 bits are not part of the
 * temperature values; they are the status bits.
 */

static inline s16 LM77_TEMP_TO_REG(int temp) { return (temp / 500) * 8; }

Contributors

PersonTokensPropCommitsCommitProp
Andras Bali1789.47%133.33%
Jean Delvare15.26%133.33%
Axel Lin15.26%133.33%
Total19100.00%3100.00%


static inline int LM77_TEMP_FROM_REG(s16 reg) { return (reg / 8) * 500; }

Contributors

PersonTokensPropCommitsCommitProp
Andras Bali1894.74%150.00%
Jean Delvare15.26%150.00%
Total19100.00%2100.00%

/* * All registers are word-sized, except for the configuration register. * The LM77 uses the high-byte first convention. */
static u16 lm77_read_value(struct i2c_client *client, u8 reg) { if (reg == LM77_REG_CONF) return i2c_smbus_read_byte_data(client, reg); else return i2c_smbus_read_word_swapped(client, reg); }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck2259.46%133.33%
Andras Bali1335.14%133.33%
Yani Ioannou25.41%133.33%
Total37100.00%3100.00%


static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) { if (reg == LM77_REG_CONF) return i2c_smbus_write_byte_data(client, reg, value); else return i2c_smbus_write_word_swapped(client, reg, value); }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck2352.27%133.33%
Andras Bali2045.45%133.33%
Yani Ioannou12.27%133.33%
Total44100.00%3100.00%


static struct lm77_data *lm77_update_device(struct device *dev) { struct lm77_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int i; mutex_lock(&data->update_lock); if (time_after(jiffies, data->last_updated + HZ + HZ / 2) || !data->valid) { dev_dbg(&client->dev, "Starting lm77 update\n"); for (i = 0; i < t_num_temp; i++) { data->temp[i] = LM77_TEMP_FROM_REG(lm77_read_value(client, temp_regs[i])); } data->alarms = lm77_read_value(client, LM77_REG_TEMP) & 0x0007; data->last_updated = jiffies; data->valid = 1; } mutex_unlock(&data->update_lock); return data; }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck8960.14%350.00%
Andras Bali3926.35%116.67%
Jean Delvare1812.16%116.67%
Ingo Molnar21.35%116.67%
Total148100.00%6100.00%

/* sysfs stuff */
static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); struct lm77_data *data = lm77_update_device(dev); return sprintf(buf, "%d\n", data->temp[attr->index]); }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck2849.12%250.00%
Jean Delvare2340.35%125.00%
Andras Bali610.53%125.00%
Total57100.00%4100.00%


static ssize_t show_temp_hyst(struct device *dev, struct device_attribute *devattr, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); struct lm77_data *data = lm77_update_device(dev); int nr = attr->index; int temp; temp = nr == t_min ? data->temp[nr] + data->temp[t_hyst] : data->temp[nr] - data->temp[t_hyst]; return sprintf(buf, "%d\n", temp); }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck8792.55%266.67%
Andras Bali77.45%133.33%
Total94100.00%3100.00%


static ssize_t set_temp(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); struct lm77_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int nr = attr->index; long val; int err; err = kstrtol(buf, 10, &val); if (err) return err; val = clamp_val(val, LM77_TEMP_MIN, LM77_TEMP_MAX); mutex_lock(&data->update_lock); data->temp[nr] = val; lm77_write_value(client, temp_regs[nr], LM77_TEMP_TO_REG(val)); mutex_unlock(&data->update_lock); return count; }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck9568.35%444.44%
Andras Bali2417.27%111.11%
Axel Lin117.91%111.11%
Mark M. Hoffman53.60%111.11%
Jean Delvare42.88%222.22%
Total139100.00%9100.00%

/* * hysteresis is stored as a relative value on the chip, so it has to be * converted first. */
static ssize_t set_temp_hyst(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) { struct lm77_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; long val; int err; err = kstrtol(buf, 10, &val); if (err) return err; mutex_lock(&data->update_lock); val = clamp_val(data->temp[t_crit] - val, LM77_TEMP_MIN, LM77_TEMP_MAX); data->temp[t_hyst] = val; lm77_write_value(client, LM77_REG_TEMP_HYST, LM77_TEMP_TO_REG(data->temp[t_hyst])); mutex_unlock(&data->update_lock); return count; }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck10479.39%450.00%
Axel Lin1612.21%112.50%
Andras Bali75.34%112.50%
Jean Delvare43.05%225.00%
Total131100.00%8100.00%


static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, char *buf) { int bitnr = to_sensor_dev_attr(attr)->index; struct lm77_data *data = lm77_update_device(dev); return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1); }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck5493.10%133.33%
Andras Bali35.17%133.33%
Jean Delvare11.72%133.33%
Total58100.00%3100.00%

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input); static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp, set_temp, t_crit); static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, t_min); static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, t_max); static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst, set_temp_hyst, t_crit); static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp_hyst, NULL, t_min); static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp_hyst, NULL, t_max); static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); static struct attribute *lm77_attrs[] = { &sensor_dev_attr_temp1_input.dev_attr.attr, &sensor_dev_attr_temp1_crit.dev_attr.attr, &sensor_dev_attr_temp1_min.dev_attr.attr, &sensor_dev_attr_temp1_max.dev_attr.attr, &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, &sensor_dev_attr_temp1_min_hyst.dev_attr.attr, &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, NULL }; ATTRIBUTE_GROUPS(lm77); /* Return 0 if detection is successful, -ENODEV otherwise */
static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info) { struct i2c_adapter *adapter = client->adapter; int i, cur, conf, hyst, crit, min, max; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) return -ENODEV; /* * Here comes the remaining detection. Since the LM77 has no * register dedicated to identification, we have to rely on the * following tricks: * * 1. the high 4 bits represent the sign and thus they should * always be the same * 2. the high 3 bits are unused in the configuration register * 3. addresses 0x06 and 0x07 return the last read value * 4. registers cycling over 8-address boundaries * * Word-sized registers are high-byte first. */ /* addresses cycling */ cur = i2c_smbus_read_word_data(client, 0); conf = i2c_smbus_read_byte_data(client, 1); hyst = i2c_smbus_read_word_data(client, 2); crit = i2c_smbus_read_word_data(client, 3); min = i2c_smbus_read_word_data(client, 4); max = i2c_smbus_read_word_data(client, 5); for (i = 8; i <= 0xff; i += 8) { if (i2c_smbus_read_byte_data(client, i + 1) != conf || i2c_smbus_read_word_data(client, i + 2) != hyst || i2c_smbus_read_word_data(client, i + 3) != crit || i2c_smbus_read_word_data(client, i + 4) != min || i2c_smbus_read_word_data(client, i + 5) != max) return -ENODEV; } /* sign bits */ if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) return -ENODEV; /* unused bits */ if (conf & 0xe0) return -ENODEV; /* 0x06 and 0x07 return the last read value */ cur = i2c_smbus_read_word_data(client, 0); if (i2c_smbus_read_word_data(client, 6) != cur || i2c_smbus_read_word_data(client, 7) != cur) return -ENODEV; hyst = i2c_smbus_read_word_data(client, 2); if (i2c_smbus_read_word_data(client, 6) != hyst || i2c_smbus_read_word_data(client, 7) != hyst) return -ENODEV; min = i2c_smbus_read_word_data(client, 4); if (i2c_smbus_read_word_data(client, 6) != min || i2c_smbus_read_word_data(client, 7) != min) return -ENODEV; strlcpy(info->type, "lm77", I2C_NAME_SIZE); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck32378.59%450.00%
Andras Bali5012.17%112.50%
Mark M. Hoffman215.11%225.00%
Jean Delvare174.14%112.50%
Total411100.00%8100.00%


static void lm77_init_client(struct i2c_client *client) { /* Initialize the LM77 chip - turn off shutdown mode */ int conf = lm77_read_value(client, LM77_REG_CONF); if (conf & 1) lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); }

Contributors

PersonTokensPropCommitsCommitProp
Andras Bali39100.00%1100.00%
Total39100.00%1100.00%


static int lm77_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; struct device *hwmon_dev; struct lm77_data *data; data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL); if (!data) return -ENOMEM; data->client = client; mutex_init(&data->update_lock); /* Initialize the LM77 chip */ lm77_init_client(client); hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, data, lm77_groups); return PTR_ERR_OR_ZERO(hwmon_dev); }

Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck6260.78%250.00%
Andras Bali3837.25%125.00%
Alexey Dobriyan21.96%125.00%
Total102100.00%4100.00%

static const struct i2c_device_id lm77_id[] = { { "lm77", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, lm77_id); /* This is the driver that will be inserted */ static struct i2c_driver lm77_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = "lm77", }, .probe = lm77_probe, .id_table = lm77_id, .detect = lm77_detect, .address_list = normal_i2c, }; module_i2c_driver(lm77_driver); MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); MODULE_DESCRIPTION("LM77 driver"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
Guenter Roeck123068.45%731.82%
Andras Bali40922.76%14.55%
Jean Delvare774.28%522.73%
Mark M. Hoffman341.89%313.64%
Axel Lin291.61%29.09%
Ingo Molnar60.33%14.55%
Alexey Dobriyan50.28%14.55%
Greg Kroah-Hartman40.22%14.55%
Yani Ioannou30.17%14.55%
Total1797100.00%22100.00%
Directory: drivers/hwmon
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