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 39 static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW }; 40 41 struct 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 */ 51 static 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 59 static inline int ad7414_read(struct i2c_client *client, u8 reg) 60 { 61 if (reg == AD7414_REG_TEMP) 62 return i2c_smbus_read_word_swapped(client, reg); 63 else 64 return i2c_smbus_read_byte_data(client, reg); 65 } 66 67 static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value) 68 { 69 return i2c_smbus_write_byte_data(client, reg, value); 70 } 71 72 static struct ad7414_data *ad7414_update_device(struct device *dev) 73 { 74 struct i2c_client *client = to_i2c_client(dev); 75 struct ad7414_data *data = i2c_get_clientdata(client); 76 77 mutex_lock(&data->lock); 78 79 if (time_after(jiffies, data->next_update) || !data->valid) { 80 int value, i; 81 82 dev_dbg(&client->dev, "starting ad7414 update\n"); 83 84 value = ad7414_read(client, AD7414_REG_TEMP); 85 if (value < 0) 86 dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n", 87 value); 88 else 89 data->temp_input = value; 90 91 for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) { 92 value = ad7414_read(client, AD7414_REG_LIMIT[i]); 93 if (value < 0) 94 dev_dbg(&client->dev, "AD7414 reg %d err %d\n", 95 AD7414_REG_LIMIT[i], value); 96 else 97 data->temps[i] = value; 98 } 99 100 data->next_update = jiffies + HZ + HZ / 2; 101 data->valid = 1; 102 } 103 104 mutex_unlock(&data->lock); 105 106 return data; 107 } 108 109 static ssize_t show_temp_input(struct device *dev, 110 struct device_attribute *attr, char *buf) 111 { 112 struct ad7414_data *data = ad7414_update_device(dev); 113 return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input)); 114 } 115 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0); 116 117 static ssize_t show_max_min(struct device *dev, struct device_attribute *attr, 118 char *buf) 119 { 120 int index = to_sensor_dev_attr(attr)->index; 121 struct ad7414_data *data = ad7414_update_device(dev); 122 return sprintf(buf, "%d\n", data->temps[index] * 1000); 123 } 124 125 static ssize_t set_max_min(struct device *dev, 126 struct device_attribute *attr, 127 const char *buf, size_t count) 128 { 129 struct i2c_client *client = to_i2c_client(dev); 130 struct ad7414_data *data = i2c_get_clientdata(client); 131 int index = to_sensor_dev_attr(attr)->index; 132 u8 reg = AD7414_REG_LIMIT[index]; 133 long temp; 134 int ret = kstrtol(buf, 10, &temp); 135 136 if (ret < 0) 137 return ret; 138 139 temp = SENSORS_LIMIT(temp, -40000, 85000); 140 temp = (temp + (temp < 0 ? -500 : 500)) / 1000; 141 142 mutex_lock(&data->lock); 143 data->temps[index] = temp; 144 ad7414_write(client, reg, temp); 145 mutex_unlock(&data->lock); 146 return count; 147 } 148 149 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, 150 show_max_min, set_max_min, 0); 151 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, 152 show_max_min, set_max_min, 1); 153 154 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, 155 char *buf) 156 { 157 int bitnr = to_sensor_dev_attr(attr)->index; 158 struct ad7414_data *data = ad7414_update_device(dev); 159 int value = (data->temp_input >> bitnr) & 1; 160 return sprintf(buf, "%d\n", value); 161 } 162 163 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3); 164 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4); 165 166 static struct attribute *ad7414_attributes[] = { 167 &sensor_dev_attr_temp1_input.dev_attr.attr, 168 &sensor_dev_attr_temp1_max.dev_attr.attr, 169 &sensor_dev_attr_temp1_min.dev_attr.attr, 170 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 171 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 172 NULL 173 }; 174 175 static const struct attribute_group ad7414_group = { 176 .attrs = ad7414_attributes, 177 }; 178 179 static int ad7414_probe(struct i2c_client *client, 180 const struct i2c_device_id *dev_id) 181 { 182 struct ad7414_data *data; 183 int conf; 184 int err; 185 186 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA | 187 I2C_FUNC_SMBUS_READ_WORD_DATA)) { 188 err = -EOPNOTSUPP; 189 goto exit; 190 } 191 192 data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL); 193 if (!data) { 194 err = -ENOMEM; 195 goto exit; 196 } 197 198 i2c_set_clientdata(client, data); 199 mutex_init(&data->lock); 200 201 dev_info(&client->dev, "chip found\n"); 202 203 /* Make sure the chip is powered up. */ 204 conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF); 205 if (conf < 0) 206 dev_warn(&client->dev, 207 "ad7414_probe unable to read config register.\n"); 208 else { 209 conf &= ~(1 << 7); 210 i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf); 211 } 212 213 /* Register sysfs hooks */ 214 err = sysfs_create_group(&client->dev.kobj, &ad7414_group); 215 if (err) 216 goto exit_free; 217 218 data->hwmon_dev = hwmon_device_register(&client->dev); 219 if (IS_ERR(data->hwmon_dev)) { 220 err = PTR_ERR(data->hwmon_dev); 221 goto exit_remove; 222 } 223 224 return 0; 225 226 exit_remove: 227 sysfs_remove_group(&client->dev.kobj, &ad7414_group); 228 exit_free: 229 kfree(data); 230 exit: 231 return err; 232 } 233 234 static int __devexit ad7414_remove(struct i2c_client *client) 235 { 236 struct ad7414_data *data = i2c_get_clientdata(client); 237 238 hwmon_device_unregister(data->hwmon_dev); 239 sysfs_remove_group(&client->dev.kobj, &ad7414_group); 240 kfree(data); 241 return 0; 242 } 243 244 static const struct i2c_device_id ad7414_id[] = { 245 { "ad7414", 0 }, 246 {} 247 }; 248 MODULE_DEVICE_TABLE(i2c, ad7414_id); 249 250 static struct i2c_driver ad7414_driver = { 251 .driver = { 252 .name = "ad7414", 253 }, 254 .probe = ad7414_probe, 255 .remove = __devexit_p(ad7414_remove), 256 .id_table = ad7414_id, 257 }; 258 259 static int __init ad7414_init(void) 260 { 261 return i2c_add_driver(&ad7414_driver); 262 } 263 module_init(ad7414_init); 264 265 static void __exit ad7414_exit(void) 266 { 267 i2c_del_driver(&ad7414_driver); 268 } 269 module_exit(ad7414_exit); 270 271 MODULE_AUTHOR("Stefan Roese <sr at denx.de>, " 272 "Frank Edelhaeuser <frank.edelhaeuser at spansion.com>"); 273 274 MODULE_DESCRIPTION("AD7414 driver"); 275 MODULE_LICENSE("GPL"); 276