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 #define ADT7411_CFG1_RESERVED_BIT3              (1 << 3)
  34
  35 #define ADT7411_REG_CFG2                        0x19
  36 #define ADT7411_CFG2_DISABLE_AVG                (1 << 5)
  37
  38 #define ADT7411_REG_CFG3                        0x1a
  39 #define ADT7411_CFG3_ADC_CLK_225                (1 << 0)
  40 #define ADT7411_CFG3_REF_VDD                    (1 << 4)
  41
  42 #define ADT7411_REG_DEVICE_ID                   0x4d
  43 #define ADT7411_REG_MANUFACTURER_ID             0x4e
  44
  45 #define ADT7411_DEVICE_ID                       0x2
  46 #define ADT7411_MANUFACTURER_ID                 0x41
  47
  48 static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };
  49
  50 struct adt7411_data {
  51         struct mutex device_lock;       /* for "atomic" device accesses */
  52         struct mutex update_lock;
  53         unsigned long next_update;
  54         int vref_cached;
  55         struct i2c_client *client;
  56 };
  57
  58 /*
  59  * When reading a register containing (up to 4) lsb, all associated
  60  * msb-registers get locked by the hardware. After _one_ of those msb is read,
  61  * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
  62  * is protected here with a mutex, too.
  63  */
  64 static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
  65                                 u8 msb_reg, u8 lsb_shift)
  66 {
  67         struct adt7411_data *data = i2c_get_clientdata(client);
  68         int val, tmp;
  69
  70         mutex_lock(&data->device_lock);
  71
  72         val = i2c_smbus_read_byte_data(client, lsb_reg);
  73         if (val < 0)
  74                 goto exit_unlock;
  75
  76         tmp = (val >> lsb_shift) & 3;
  77         val = i2c_smbus_read_byte_data(client, msb_reg);
  78
  79         if (val >= 0)
  80                 val = (val << 2) | tmp;
  81
  82  exit_unlock:
  83         mutex_unlock(&data->device_lock);
  84
  85         return val;
  86 }
  87
  88 static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
  89                                 bool flag)
  90 {
  91         struct adt7411_data *data = i2c_get_clientdata(client);
  92         int ret, val;
  93
  94         mutex_lock(&data->device_lock);
  95
  96         ret = i2c_smbus_read_byte_data(client, reg);
  97         if (ret < 0)
  98                 goto exit_unlock;
  99
 100         if (flag)
 101                 val = ret | bit;
 102         else
 103                 val = ret & ~bit;
 104
 105         ret = i2c_smbus_write_byte_data(client, reg, val);
 106
 107  exit_unlock:
 108         mutex_unlock(&data->device_lock);
 109         return ret;
 110 }
 111
 112 static ssize_t adt7411_show_vdd(struct device *dev,
 113                                 struct device_attribute *attr, char *buf)
 114 {
 115         struct adt7411_data *data = dev_get_drvdata(dev);
 116         struct i2c_client *client = data->client;
 117         int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 118                         ADT7411_REG_VDD_MSB, 2);
 119
 120         return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
 121 }
 122
 123 static ssize_t adt7411_show_temp(struct device *dev,
 124                         struct device_attribute *attr, char *buf)
 125 {
 126         struct adt7411_data *data = dev_get_drvdata(dev);
 127         struct i2c_client *client = data->client;
 128         int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 129                         ADT7411_REG_INT_TEMP_MSB, 0);
 130
 131         if (val < 0)
 132                 return val;
 133
 134         val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */
 135
 136         return sprintf(buf, "%d\n", val * 250);
 137 }
 138
 139 static ssize_t adt7411_show_input(struct device *dev,
 140                                   struct device_attribute *attr, char *buf)
 141 {
 142         int nr = to_sensor_dev_attr(attr)->index;
 143         struct adt7411_data *data = dev_get_drvdata(dev);
 144         struct i2c_client *client = data->client;
 145         int val;
 146         u8 lsb_reg, lsb_shift;
 147
 148         mutex_lock(&data->update_lock);
 149         if (time_after_eq(jiffies, data->next_update)) {
 150                 val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
 151                 if (val < 0)
 152                         goto exit_unlock;
 153
 154                 if (val & ADT7411_CFG3_REF_VDD) {
 155                         val = adt7411_read_10_bit(client,
 156                                         ADT7411_REG_INT_TEMP_VDD_LSB,
 157                                         ADT7411_REG_VDD_MSB, 2);
 158                         if (val < 0)
 159                                 goto exit_unlock;
 160
 161                         data->vref_cached = val * 7000 / 1024;
 162                 } else {
 163                         data->vref_cached = 2250;
 164                 }
 165
 166                 data->next_update = jiffies + HZ;
 167         }
 168
 169         lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
 170         lsb_shift = 2 * (nr & 0x03);
 171         val = adt7411_read_10_bit(client, lsb_reg,
 172                         ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
 173         if (val < 0)
 174                 goto exit_unlock;
 175
 176         val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
 177  exit_unlock:
 178         mutex_unlock(&data->update_lock);
 179         return val;
 180 }
 181
 182 static ssize_t adt7411_show_bit(struct device *dev,
 183                                 struct device_attribute *attr, char *buf)
 184 {
 185         struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
 186         struct adt7411_data *data = dev_get_drvdata(dev);
 187         struct i2c_client *client = data->client;
 188         int ret = i2c_smbus_read_byte_data(client, attr2->index);
 189
 190         return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
 191 }
 192
 193 static ssize_t adt7411_set_bit(struct device *dev,
 194                                struct device_attribute *attr, const char *buf,
 195                                size_t count)
 196 {
 197         struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
 198         struct adt7411_data *data = dev_get_drvdata(dev);
 199         struct i2c_client *client = data->client;
 200         int ret;
 201         unsigned long flag;
 202
 203         ret = kstrtoul(buf, 0, &flag);
 204         if (ret || flag > 1)
 205                 return -EINVAL;
 206
 207         ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
 208
 209         /* force update */
 210         mutex_lock(&data->update_lock);
 211         data->next_update = jiffies;
 212         mutex_unlock(&data->update_lock);
 213
 214         return ret < 0 ? ret : count;
 215 }
 216
 217 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \
 218         SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
 219         adt7411_set_bit, __bit, __reg)
 220
 221 static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
 222 static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
 223 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
 224 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
 225 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
 226 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
 227 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
 228 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
 229 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
 230 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
 231 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
 232 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
 233 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
 234
 235 static struct attribute *adt7411_attrs[] = {
 236         &dev_attr_temp1_input.attr,
 237         &dev_attr_in0_input.attr,
 238         &sensor_dev_attr_in1_input.dev_attr.attr,
 239         &sensor_dev_attr_in2_input.dev_attr.attr,
 240         &sensor_dev_attr_in3_input.dev_attr.attr,
 241         &sensor_dev_attr_in4_input.dev_attr.attr,
 242         &sensor_dev_attr_in5_input.dev_attr.attr,
 243         &sensor_dev_attr_in6_input.dev_attr.attr,
 244         &sensor_dev_attr_in7_input.dev_attr.attr,
 245         &sensor_dev_attr_in8_input.dev_attr.attr,
 246         &sensor_dev_attr_no_average.dev_attr.attr,
 247         &sensor_dev_attr_fast_sampling.dev_attr.attr,
 248         &sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
 249         NULL
 250 };
 251
 252 ATTRIBUTE_GROUPS(adt7411);
 253
 254 static int adt7411_detect(struct i2c_client *client,
 255                           struct i2c_board_info *info)
 256 {
 257         int val;
 258
 259         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 260                 return -ENODEV;
 261
 262         val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
 263         if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
 264                 dev_dbg(&client->dev,
 265                         "Wrong manufacturer ID. Got %d, expected %d\n",
 266                         val, ADT7411_MANUFACTURER_ID);
 267                 return -ENODEV;
 268         }
 269
 270         val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
 271         if (val < 0 || val != ADT7411_DEVICE_ID) {
 272                 dev_dbg(&client->dev,
 273                         "Wrong device ID. Got %d, expected %d\n",
 274                         val, ADT7411_DEVICE_ID);
 275                 return -ENODEV;
 276         }
 277
 278         strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
 279
 280         return 0;
 281 }
 282
 283 static int adt7411_probe(struct i2c_client *client,
 284                                    const struct i2c_device_id *id)
 285 {
 286         struct device *dev = &client->dev;
 287         struct adt7411_data *data;
 288         struct device *hwmon_dev;
 289         int ret;
 290
 291         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 292         if (!data)
 293                 return -ENOMEM;
 294
 295         i2c_set_clientdata(client, data);
 296         data->client = client;
 297         mutex_init(&data->device_lock);
 298         mutex_init(&data->update_lock);
 299
 300         /* According to the datasheet, we must only write 1 to bit 3 */
 301         ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
 302                                  ADT7411_CFG1_RESERVED_BIT3
 303                                  | ADT7411_CFG1_START_MONITOR, 1);
 304         if (ret < 0)
 305                 return ret;
 306
 307         /* force update on first occasion */
 308         data->next_update = jiffies;
 309
 310         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 311                                                            data,
 312                                                            adt7411_groups);
 313         return PTR_ERR_OR_ZERO(hwmon_dev);
 314 }
 315
 316 static const struct i2c_device_id adt7411_id[] = {
 317         { "adt7411", 0 },
 318         { }
 319 };
 320 MODULE_DEVICE_TABLE(i2c, adt7411_id);
 321
 322 static struct i2c_driver adt7411_driver = {
 323         .driver         = {
 324                 .name           = "adt7411",
 325         },
 326         .probe  = adt7411_probe,
 327         .id_table = adt7411_id,
 328         .detect = adt7411_detect,
 329         .address_list = normal_i2c,
 330         .class = I2C_CLASS_HWMON,
 331 };
 332
 333 module_i2c_driver(adt7411_driver);
 334
 335 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
 336         "Wolfram Sang <w.sang@pengutronix.de>");
 337 MODULE_DESCRIPTION("ADT7411 driver");
 338 MODULE_LICENSE("GPL v2");