drivers/hwmon/adt7411.c

   1 /*
   2  *  Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
   3  *
   4  *  Copyright (C) 2008, 2010 Pengutronix
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License version 2 as
   8  *  published by the Free Software Foundation.
   9  *
  10  *  TODO: SPI, support for external temperature sensor
  11  *        use power-down mode for suspend?, interrupt handling?
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/err.h>
  18 #include <linux/mutex.h>
  19 #include <linux/jiffies.h>
  20 #include <linux/i2c.h>
  21 #include <linux/hwmon.h>
  22 #include <linux/hwmon-sysfs.h>
  23 #include <linux/slab.h>
  24
  25 #define ADT7411_REG_INT_TEMP_VDD_LSB            0x03
  26 #define ADT7411_REG_EXT_TEMP_AIN14_LSB          0x04
  27 #define ADT7411_REG_VDD_MSB                     0x06
  28 #define ADT7411_REG_INT_TEMP_MSB                0x07
  29 #define ADT7411_REG_EXT_TEMP_AIN1_MSB           0x08
  30
  31 #define ADT7411_REG_CFG1                        0x18
  32 #define ADT7411_CFG1_START_MONITOR              (1 << 0)
  33
  34 #define ADT7411_REG_CFG2                        0x19
  35 #define ADT7411_CFG2_DISABLE_AVG                (1 << 5)
  36
  37 #define ADT7411_REG_CFG3                        0x1a
  38 #define ADT7411_CFG3_ADC_CLK_225                (1 << 0)
  39 #define ADT7411_CFG3_REF_VDD                    (1 << 4)
  40
  41 #define ADT7411_REG_DEVICE_ID                   0x4d
  42 #define ADT7411_REG_MANUFACTURER_ID             0x4e
  43
  44 #define ADT7411_DEVICE_ID                       0x2
  45 #define ADT7411_MANUFACTURER_ID                 0x41
  46
  47 static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };
  48
  49 struct adt7411_data {
  50         struct mutex device_lock;       /* for "atomic" device accesses */
  51         struct mutex update_lock;
  52         unsigned long next_update;
  53         int vref_cached;
  54         struct device *hwmon_dev;
  55 };
  56
  57 /*
  58  * When reading a register containing (up to 4) lsb, all associated
  59  * msb-registers get locked by the hardware. After _one_ of those msb is read,
  60  * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
  61  * is protected here with a mutex, too.
  62  */
  63 static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
  64                                 u8 msb_reg, u8 lsb_shift)
  65 {
  66         struct adt7411_data *data = i2c_get_clientdata(client);
  67         int val, tmp;
  68
  69         mutex_lock(&data->device_lock);
  70
  71         val = i2c_smbus_read_byte_data(client, lsb_reg);
  72         if (val < 0)
  73                 goto exit_unlock;
  74
  75         tmp = (val >> lsb_shift) & 3;
  76         val = i2c_smbus_read_byte_data(client, msb_reg);
  77
  78         if (val >= 0)
  79                 val = (val << 2) | tmp;
  80
  81  exit_unlock:
  82         mutex_unlock(&data->device_lock);
  83
  84         return val;
  85 }
  86
  87 static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
  88                                 bool flag)
  89 {
  90         struct adt7411_data *data = i2c_get_clientdata(client);
  91         int ret, val;
  92
  93         mutex_lock(&data->device_lock);
  94
  95         ret = i2c_smbus_read_byte_data(client, reg);
  96         if (ret < 0)
  97                 goto exit_unlock;
  98
  99         if (flag)
 100                 val = ret | bit;
 101         else
 102                 val = ret & ~bit;
 103
 104         ret = i2c_smbus_write_byte_data(client, reg, val);
 105
 106  exit_unlock:
 107         mutex_unlock(&data->device_lock);
 108         return ret;
 109 }
 110
 111 static ssize_t adt7411_show_vdd(struct device *dev,
 112                                 struct device_attribute *attr, char *buf)
 113 {
 114         struct i2c_client *client = to_i2c_client(dev);
 115         int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 116                         ADT7411_REG_VDD_MSB, 2);
 117
 118         return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
 119 }
 120
 121 static ssize_t adt7411_show_temp(struct device *dev,
 122                         struct device_attribute *attr, char *buf)
 123 {
 124         struct i2c_client *client = to_i2c_client(dev);
 125         int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 126                         ADT7411_REG_INT_TEMP_MSB, 0);
 127
 128         if (val < 0)
 129                 return val;
 130
 131         val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */
 132
 133         return sprintf(buf, "%d\n", val * 250);
 134 }
 135
 136 static ssize_t adt7411_show_input(struct device *dev,
 137                                   struct device_attribute *attr, char *buf)
 138 {
 139         int nr = to_sensor_dev_attr(attr)->index;
 140         struct i2c_client *client = to_i2c_client(dev);
 141         struct adt7411_data *data = i2c_get_clientdata(client);
 142         int val;
 143         u8 lsb_reg, lsb_shift;
 144
 145         mutex_lock(&data->update_lock);
 146         if (time_after_eq(jiffies, data->next_update)) {
 147                 val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
 148                 if (val < 0)
 149                         goto exit_unlock;
 150
 151                 if (val & ADT7411_CFG3_REF_VDD) {
 152                         val = adt7411_read_10_bit(client,
 153                                         ADT7411_REG_INT_TEMP_VDD_LSB,
 154                                         ADT7411_REG_VDD_MSB, 2);
 155                         if (val < 0)
 156                                 goto exit_unlock;
 157
 158                         data->vref_cached = val * 7000 / 1024;
 159                 } else {
 160                         data->vref_cached = 2250;
 161                 }
 162
 163                 data->next_update = jiffies + HZ;
 164         }
 165
 166         lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
 167         lsb_shift = 2 * (nr & 0x03);
 168         val = adt7411_read_10_bit(client, lsb_reg,
 169                         ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
 170         if (val < 0)
 171                 goto exit_unlock;
 172
 173         val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
 174  exit_unlock:
 175         mutex_unlock(&data->update_lock);
 176         return val;
 177 }
 178
 179 static ssize_t adt7411_show_bit(struct device *dev,
 180                                 struct device_attribute *attr, char *buf)
 181 {
 182         struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
 183         struct i2c_client *client = to_i2c_client(dev);
 184         int ret = i2c_smbus_read_byte_data(client, attr2->index);
 185
 186         return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
 187 }
 188
 189 static ssize_t adt7411_set_bit(struct device *dev,
 190                                struct device_attribute *attr, const char *buf,
 191                                size_t count)
 192 {
 193         struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
 194         struct i2c_client *client = to_i2c_client(dev);
 195         struct adt7411_data *data = i2c_get_clientdata(client);
 196         int ret;
 197         unsigned long flag;
 198
 199         ret = kstrtoul(buf, 0, &flag);
 200         if (ret || flag > 1)
 201                 return -EINVAL;
 202
 203         ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
 204
 205         /* force update */
 206         mutex_lock(&data->update_lock);
 207         data->next_update = jiffies;
 208         mutex_unlock(&data->update_lock);
 209
 210         return ret < 0 ? ret : count;
 211 }
 212
 213 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \
 214         SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
 215         adt7411_set_bit, __bit, __reg)
 216
 217 static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
 218 static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
 219 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
 220 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
 221 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
 222 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
 223 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
 224 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
 225 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
 226 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
 227 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
 228 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
 229 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
 230
 231 static struct attribute *adt7411_attrs[] = {
 232         &dev_attr_temp1_input.attr,
 233         &dev_attr_in0_input.attr,
 234         &sensor_dev_attr_in1_input.dev_attr.attr,
 235         &sensor_dev_attr_in2_input.dev_attr.attr,
 236         &sensor_dev_attr_in3_input.dev_attr.attr,
 237         &sensor_dev_attr_in4_input.dev_attr.attr,
 238         &sensor_dev_attr_in5_input.dev_attr.attr,
 239         &sensor_dev_attr_in6_input.dev_attr.attr,
 240         &sensor_dev_attr_in7_input.dev_attr.attr,
 241         &sensor_dev_attr_in8_input.dev_attr.attr,
 242         &sensor_dev_attr_no_average.dev_attr.attr,
 243         &sensor_dev_attr_fast_sampling.dev_attr.attr,
 244         &sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
 245         NULL
 246 };
 247
 248 static const struct attribute_group adt7411_attr_grp = {
 249         .attrs = adt7411_attrs,
 250 };
 251
 252 static int adt7411_detect(struct i2c_client *client,
 253                           struct i2c_board_info *info)
 254 {
 255         int val;
 256
 257         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 258                 return -ENODEV;
 259
 260         val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
 261         if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
 262                 dev_dbg(&client->dev, "Wrong manufacturer ID. Got %d, "
 263                         "expected %d\n", val, ADT7411_MANUFACTURER_ID);
 264                 return -ENODEV;
 265         }
 266
 267         val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
 268         if (val < 0 || val != ADT7411_DEVICE_ID) {
 269                 dev_dbg(&client->dev, "Wrong device ID. Got %d, "
 270                         "expected %d\n", val, ADT7411_DEVICE_ID);
 271                 return -ENODEV;
 272         }
 273
 274         strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
 275
 276         return 0;
 277 }
 278
 279 static int adt7411_probe(struct i2c_client *client,
 280                                    const struct i2c_device_id *id)
 281 {
 282         struct adt7411_data *data;
 283         int ret;
 284
 285         data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
 286         if (!data)
 287                 return -ENOMEM;
 288
 289         i2c_set_clientdata(client, data);
 290         mutex_init(&data->device_lock);
 291         mutex_init(&data->update_lock);
 292
 293         ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
 294                                  ADT7411_CFG1_START_MONITOR, 1);
 295         if (ret < 0)
 296                 return ret;
 297
 298         /* force update on first occasion */
 299         data->next_update = jiffies;
 300
 301         ret = sysfs_create_group(&client->dev.kobj, &adt7411_attr_grp);
 302         if (ret)
 303                 return ret;
 304
 305         data->hwmon_dev = hwmon_device_register(&client->dev);
 306         if (IS_ERR(data->hwmon_dev)) {
 307                 ret = PTR_ERR(data->hwmon_dev);
 308                 goto exit_remove;
 309         }
 310
 311         dev_info(&client->dev, "successfully registered\n");
 312
 313         return 0;
 314
 315  exit_remove:
 316         sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
 317         return ret;
 318 }
 319
 320 static int adt7411_remove(struct i2c_client *client)
 321 {
 322         struct adt7411_data *data = i2c_get_clientdata(client);
 323
 324         hwmon_device_unregister(data->hwmon_dev);
 325         sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
 326         return 0;
 327 }
 328
 329 static const struct i2c_device_id adt7411_id[] = {
 330         { "adt7411", 0 },
 331         { }
 332 };
 333 MODULE_DEVICE_TABLE(i2c, adt7411_id);
 334
 335 static struct i2c_driver adt7411_driver = {
 336         .driver         = {
 337                 .name           = "adt7411",
 338         },
 339         .probe  = adt7411_probe,
 340         .remove = adt7411_remove,
 341         .id_table = adt7411_id,
 342         .detect = adt7411_detect,
 343         .address_list = normal_i2c,
 344         .class = I2C_CLASS_HWMON,
 345 };
 346
 347 module_i2c_driver(adt7411_driver);
 348
 349 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
 350         "Wolfram Sang <w.sang@pengutronix.de>");
 351 MODULE_DESCRIPTION("ADT7411 driver");
 352 MODULE_LICENSE("GPL v2");