diff options
Diffstat (limited to 'drivers/hwmon/ad7414.c')
| -rw-r--r-- | drivers/hwmon/ad7414.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/drivers/hwmon/ad7414.c b/drivers/hwmon/ad7414.c new file mode 100644 index 0000000..bfda8c8 --- /dev/null +++ b/drivers/hwmon/ad7414.c @@ -0,0 +1,268 @@ +/* + * An hwmon driver for the Analog Devices AD7414 + * + * Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering + * + * Copyright (c) 2008 PIKA Technologies + * Sean MacLennan <smaclennan@pikatech.com> + * + * Copyright (c) 2008 Spansion Inc. + * Frank Edelhaeuser <frank.edelhaeuser at spansion.com> + * (converted to "new style" I2C driver model, removed checkpatch.pl warnings) + * + * Based on ad7418.c + * Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it> + * + * 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/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> + + +/* AD7414 registers */ +#define AD7414_REG_TEMP 0x00 +#define AD7414_REG_CONF 0x01 +#define AD7414_REG_T_HIGH 0x02 +#define AD7414_REG_T_LOW 0x03 + +static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW }; + +struct ad7414_data { + struct device *hwmon_dev; + struct mutex lock; /* atomic read data updates */ + char valid; /* !=0 if following fields are valid */ + unsigned long next_update; /* In jiffies */ + s16 temp_input; /* Register values */ + s8 temps[ARRAY_SIZE(AD7414_REG_LIMIT)]; +}; + +/* REG: (0.25C/bit, two's complement) << 6 */ +static inline int ad7414_temp_from_reg(s16 reg) +{ + /* use integer division instead of equivalent right shift to + * guarantee arithmetic shift and preserve the sign + */ + return ((int)reg / 64) * 250; +} + +static inline int ad7414_read(struct i2c_client *client, u8 reg) +{ + if (reg == AD7414_REG_TEMP) { + int value = i2c_smbus_read_word_data(client, reg); + return (value < 0) ? value : swab16(value); + } else + return i2c_smbus_read_byte_data(client, reg); +} + +static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value) +{ + return i2c_smbus_write_byte_data(client, reg, value); +} + +static struct ad7414_data *ad7414_update_device(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ad7414_data *data = i2c_get_clientdata(client); + + mutex_lock(&data->lock); + + if (time_after(jiffies, data->next_update) || !data->valid) { + int value, i; + + dev_dbg(&client->dev, "starting ad7414 update\n"); + + value = ad7414_read(client, AD7414_REG_TEMP); + if (value < 0) + dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n", + value); + else + data->temp_input = value; + + for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) { + value = ad7414_read(client, AD7414_REG_LIMIT[i]); + if (value < 0) + dev_dbg(&client->dev, "AD7414 reg %d err %d\n", + AD7414_REG_LIMIT[i], value); + else + data->temps[i] = value; + } + + data->next_update = jiffies + HZ + HZ / 2; + data->valid = 1; + } + + mutex_unlock(&data->lock); + + return data; +} + +static ssize_t show_temp_input(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ad7414_data *data = ad7414_update_device(dev); + return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input)); +} +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0); + +static ssize_t show_max_min(struct device *dev, struct device_attribute *attr, + char *buf) +{ + int index = to_sensor_dev_attr(attr)->index; + struct ad7414_data *data = ad7414_update_device(dev); + return sprintf(buf, "%d\n", data->temps[index] * 1000); +} + +static ssize_t set_max_min(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ad7414_data *data = i2c_get_clientdata(client); + int index = to_sensor_dev_attr(attr)->index; + u8 reg = AD7414_REG_LIMIT[index]; + long temp = simple_strtol(buf, NULL, 10); + + temp = SENSORS_LIMIT(temp, -40000, 85000); + temp = (temp + (temp < 0 ? -500 : 500)) / 1000; + + mutex_lock(&data->lock); + data->temps[index] = temp; + ad7414_write(client, reg, temp); + mutex_unlock(&data->lock); + return count; +} + +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, + show_max_min, set_max_min, 0); +static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, + show_max_min, set_max_min, 1); + +static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, + char *buf) +{ + int bitnr = to_sensor_dev_attr(attr)->index; + struct ad7414_data *data = ad7414_update_device(dev); + int value = (data->temp_input >> bitnr) & 1; + return sprintf(buf, "%d\n", value); +} + +static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3); +static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4); + +static struct attribute *ad7414_attributes[] = { + &sensor_dev_attr_temp1_input.dev_attr.attr, + &sensor_dev_attr_temp1_max.dev_attr.attr, + &sensor_dev_attr_temp1_min.dev_attr.attr, + &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, + &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, + NULL +}; + +static const struct attribute_group ad7414_group = { + .attrs = ad7414_attributes, +}; + +static int ad7414_probe(struct i2c_client *client, + const struct i2c_device_id *dev_id) +{ + struct ad7414_data *data; + int conf; + int err = 0; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_READ_WORD_DATA)) + goto exit; + + data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL); + if (!data) { + err = -ENOMEM; + goto exit; + } + + i2c_set_clientdata(client, data); + mutex_init(&data->lock); + + dev_info(&client->dev, "chip found\n"); + + /* Make sure the chip is powered up. */ + conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF); + if (conf < 0) + dev_warn(&client->dev, + "ad7414_probe unable to read config register.\n"); + else { + conf &= ~(1 << 7); + i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf); + } + + /* Register sysfs hooks */ + err = sysfs_create_group(&client->dev.kobj, &ad7414_group); + if (err) + goto exit_free; + + data->hwmon_dev = hwmon_device_register(&client->dev); + if (IS_ERR(data->hwmon_dev)) { + err = PTR_ERR(data->hwmon_dev); + goto exit_remove; + } + + return 0; + +exit_remove: + sysfs_remove_group(&client->dev.kobj, &ad7414_group); +exit_free: + kfree(data); +exit: + return err; +} + +static int __devexit ad7414_remove(struct i2c_client *client) +{ + struct ad7414_data *data = i2c_get_clientdata(client); + + hwmon_device_unregister(data->hwmon_dev); + sysfs_remove_group(&client->dev.kobj, &ad7414_group); + kfree(data); + return 0; +} + +static const struct i2c_device_id ad7414_id[] = { + { "ad7414", 0 }, + {} +}; + +static struct i2c_driver ad7414_driver = { + .driver = { + .name = "ad7414", + }, + .probe = ad7414_probe, + .remove = __devexit_p(ad7414_remove), + .id_table = ad7414_id, +}; + +static int __init ad7414_init(void) +{ + return i2c_add_driver(&ad7414_driver); +} +module_init(ad7414_init); + +static void __exit ad7414_exit(void) +{ + i2c_del_driver(&ad7414_driver); +} +module_exit(ad7414_exit); + +MODULE_AUTHOR("Stefan Roese <sr at denx.de>, " + "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>"); + +MODULE_DESCRIPTION("AD7414 driver"); +MODULE_LICENSE("GPL"); |
