1/* 2 * An hwmon driver for the Analog Devices AD7414 3 * 4 * Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering 5 * 6 * Copyright (c) 2008 PIKA Technologies 7 * Sean MacLennan <smaclennan@pikatech.com> 8 * 9 * Copyright (c) 2008 Spansion Inc. 10 * Frank Edelhaeuser <frank.edelhaeuser at spansion.com> 11 * (converted to "new style" I2C driver model, removed checkpatch.pl warnings) 12 * 13 * Based on ad7418.c 14 * Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it> 15 * 16 * This program is free software; you can redistribute it and/or modify 17 * it under the terms of the GNU General Public License as published by 18 * the Free Software Foundation; either version 2 of the License, or 19 * (at your option) any later version. 20 */ 21 22#include <linux/module.h> 23#include <linux/jiffies.h> 24#include <linux/i2c.h> 25#include <linux/hwmon.h> 26#include <linux/hwmon-sysfs.h> 27#include <linux/err.h> 28#include <linux/mutex.h> 29#include <linux/sysfs.h> 30#include <linux/slab.h> 31 32 33/* AD7414 registers */ 34#define AD7414_REG_TEMP 0x00 35#define AD7414_REG_CONF 0x01 36#define AD7414_REG_T_HIGH 0x02 37#define AD7414_REG_T_LOW 0x03 38 39static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW }; 40 41struct ad7414_data { 42 struct device *hwmon_dev; 43 struct mutex lock; /* atomic read data updates */ 44 char valid; /* !=0 if following fields are valid */ 45 unsigned long next_update; /* In jiffies */ 46 s16 temp_input; /* Register values */ 47 s8 temps[ARRAY_SIZE(AD7414_REG_LIMIT)]; 48}; 49 50/* REG: (0.25C/bit, two's complement) << 6 */ 51static inline int ad7414_temp_from_reg(s16 reg) 52{ 53 /* use integer division instead of equivalent right shift to 54 * guarantee arithmetic shift and preserve the sign 55 */ 56 return ((int)reg / 64) * 250; 57} 58 59static inline int ad7414_read(struct i2c_client *client, u8 reg) 60{ 61 if (reg == AD7414_REG_TEMP) { 62 int value = i2c_smbus_read_word_data(client, reg); 63 return (value < 0) ? value : swab16(value); 64 } else 65 return i2c_smbus_read_byte_data(client, reg); 66} 67 68static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value) 69{ 70 return i2c_smbus_write_byte_data(client, reg, value); 71} 72 73static struct ad7414_data *ad7414_update_device(struct device *dev) 74{ 75 struct i2c_client *client = to_i2c_client(dev); 76 struct ad7414_data *data = i2c_get_clientdata(client); 77 78 mutex_lock(&data->lock); 79 80 if (time_after(jiffies, data->next_update) || !data->valid) { 81 int value, i; 82 83 dev_dbg(&client->dev, "starting ad7414 update\n"); 84 85 value = ad7414_read(client, AD7414_REG_TEMP); 86 if (value < 0) 87 dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n", 88 value); 89 else 90 data->temp_input = value; 91 92 for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) { 93 value = ad7414_read(client, AD7414_REG_LIMIT[i]); 94 if (value < 0) 95 dev_dbg(&client->dev, "AD7414 reg %d err %d\n", 96 AD7414_REG_LIMIT[i], value); 97 else 98 data->temps[i] = value; 99 } 100 101 data->next_update = jiffies + HZ + HZ / 2; 102 data->valid = 1; 103 } 104 105 mutex_unlock(&data->lock); 106 107 return data; 108} 109 110static ssize_t show_temp_input(struct device *dev, 111 struct device_attribute *attr, char *buf) 112{ 113 struct ad7414_data *data = ad7414_update_device(dev); 114 return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input)); 115} 116static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0); 117 118static ssize_t show_max_min(struct device *dev, struct device_attribute *attr, 119 char *buf) 120{ 121 int index = to_sensor_dev_attr(attr)->index; 122 struct ad7414_data *data = ad7414_update_device(dev); 123 return sprintf(buf, "%d\n", data->temps[index] * 1000); 124} 125 126static ssize_t set_max_min(struct device *dev, 127 struct device_attribute *attr, 128 const char *buf, size_t count) 129{ 130 struct i2c_client *client = to_i2c_client(dev); 131 struct ad7414_data *data = i2c_get_clientdata(client); 132 int index = to_sensor_dev_attr(attr)->index; 133 u8 reg = AD7414_REG_LIMIT[index]; 134 long temp = simple_strtol(buf, NULL, 10); 135 136 temp = SENSORS_LIMIT(temp, -40000, 85000); 137 temp = (temp + (temp < 0 ? -500 : 500)) / 1000; 138 139 mutex_lock(&data->lock); 140 data->temps[index] = temp; 141 ad7414_write(client, reg, temp); 142 mutex_unlock(&data->lock); 143 return count; 144} 145 146static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, 147 show_max_min, set_max_min, 0); 148static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, 149 show_max_min, set_max_min, 1); 150 151static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, 152 char *buf) 153{ 154 int bitnr = to_sensor_dev_attr(attr)->index; 155 struct ad7414_data *data = ad7414_update_device(dev); 156 int value = (data->temp_input >> bitnr) & 1; 157 return sprintf(buf, "%d\n", value); 158} 159 160static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3); 161static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4); 162 163static struct attribute *ad7414_attributes[] = { 164 &sensor_dev_attr_temp1_input.dev_attr.attr, 165 &sensor_dev_attr_temp1_max.dev_attr.attr, 166 &sensor_dev_attr_temp1_min.dev_attr.attr, 167 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 168 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 169 NULL 170}; 171 172static const struct attribute_group ad7414_group = { 173 .attrs = ad7414_attributes, 174}; 175 176static int ad7414_probe(struct i2c_client *client, 177 const struct i2c_device_id *dev_id) 178{ 179 struct ad7414_data *data; 180 int conf; 181 int err = 0; 182 183 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA | 184 I2C_FUNC_SMBUS_READ_WORD_DATA)) 185 goto exit; 186 187 data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL); 188 if (!data) { 189 err = -ENOMEM; 190 goto exit; 191 } 192 193 i2c_set_clientdata(client, data); 194 mutex_init(&data->lock); 195 196 dev_info(&client->dev, "chip found\n"); 197 198 /* Make sure the chip is powered up. */ 199 conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF); 200 if (conf < 0) 201 dev_warn(&client->dev, 202 "ad7414_probe unable to read config register.\n"); 203 else { 204 conf &= ~(1 << 7); 205 i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf); 206 } 207 208 /* Register sysfs hooks */ 209 err = sysfs_create_group(&client->dev.kobj, &ad7414_group); 210 if (err) 211 goto exit_free; 212 213 data->hwmon_dev = hwmon_device_register(&client->dev); 214 if (IS_ERR(data->hwmon_dev)) { 215 err = PTR_ERR(data->hwmon_dev); 216 goto exit_remove; 217 } 218 219 return 0; 220 221exit_remove: 222 sysfs_remove_group(&client->dev.kobj, &ad7414_group); 223exit_free: 224 kfree(data); 225exit: 226 return err; 227} 228 229static int __devexit ad7414_remove(struct i2c_client *client) 230{ 231 struct ad7414_data *data = i2c_get_clientdata(client); 232 233 hwmon_device_unregister(data->hwmon_dev); 234 sysfs_remove_group(&client->dev.kobj, &ad7414_group); 235 kfree(data); 236 return 0; 237} 238 239static const struct i2c_device_id ad7414_id[] = { 240 { "ad7414", 0 }, 241 {} 242}; 243 244static struct i2c_driver ad7414_driver = { 245 .driver = { 246 .name = "ad7414", 247 }, 248 .probe = ad7414_probe, 249 .remove = __devexit_p(ad7414_remove), 250 .id_table = ad7414_id, 251}; 252 253static int __init ad7414_init(void) 254{ 255 return i2c_add_driver(&ad7414_driver); 256} 257module_init(ad7414_init); 258 259static void __exit ad7414_exit(void) 260{ 261 i2c_del_driver(&ad7414_driver); 262} 263module_exit(ad7414_exit); 264 265MODULE_AUTHOR("Stefan Roese <sr at denx.de>, " 266 "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>"); 267 268MODULE_DESCRIPTION("AD7414 driver"); 269MODULE_LICENSE("GPL"); 270