diff options
Diffstat (limited to 'drivers/hwmon/ad7414.c')
| -rw-r--r-- | drivers/hwmon/ad7414.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/drivers/hwmon/ad7414.c b/drivers/hwmon/ad7414.c new file mode 100644 index 000000000..cec227f13 --- /dev/null +++ b/drivers/hwmon/ad7414.c @@ -0,0 +1,241 @@ +/* + * 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> +#include <linux/slab.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 i2c_client *client; + 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) + return i2c_smbus_read_word_swapped(client, reg); + 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 ad7414_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->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 ad7414_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + int index = to_sensor_dev_attr(attr)->index; + u8 reg = AD7414_REG_LIMIT[index]; + long temp; + int ret = kstrtol(buf, 10, &temp); + + if (ret < 0) + return ret; + + temp = clamp_val(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_attrs[] = { + &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 +}; + +ATTRIBUTE_GROUPS(ad7414); + +static int ad7414_probe(struct i2c_client *client, + const struct i2c_device_id *dev_id) +{ + struct device *dev = &client->dev; + struct ad7414_data *data; + struct device *hwmon_dev; + int conf; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_READ_WORD_DATA)) + return -EOPNOTSUPP; + + data = devm_kzalloc(dev, sizeof(struct ad7414_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->client = client; + 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(dev, "ad7414_probe unable to read config register.\n"); + else { + conf &= ~(1 << 7); + i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf); + } + + hwmon_dev = devm_hwmon_device_register_with_groups(dev, + client->name, + data, ad7414_groups); + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct i2c_device_id ad7414_id[] = { + { "ad7414", 0 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, ad7414_id); + +static const struct of_device_id ad7414_of_match[] = { + { .compatible = "ad,ad7414" }, + { }, +}; +MODULE_DEVICE_TABLE(of, ad7414_of_match); + +static struct i2c_driver ad7414_driver = { + .driver = { + .name = "ad7414", + .of_match_table = of_match_ptr(ad7414_of_match), + }, + .probe = ad7414_probe, + .id_table = ad7414_id, +}; + +module_i2c_driver(ad7414_driver); + +MODULE_AUTHOR("Stefan Roese <sr at denx.de>, " + "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>"); + +MODULE_DESCRIPTION("AD7414 driver"); +MODULE_LICENSE("GPL"); |