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 i2c_client *client;
  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 adt7411_data *data = dev_get_drvdata(dev);
 115         struct i2c_client *client = data->client;
 116         int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 117                         ADT7411_REG_VDD_MSB, 2);
 118
 119         return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
 120 }
 121
 122 static ssize_t adt7411_show_temp(struct device *dev,
 123                         struct device_attribute *attr, char *buf)
 124 {
 125         struct adt7411_data *data = dev_get_drvdata(dev);
 126         struct i2c_client *client = data->client;
 127         int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
 128                         ADT7411_REG_INT_TEMP_MSB, 0);
 129
 130         if (val < 0)
 131                 return val;
 132
 133         val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */
 134
 135         return sprintf(buf, "%d\n", val * 250);
 136 }
 137
 138 static ssize_t adt7411_show_input(struct device *dev,
 139                                   struct device_attribute *attr, char *buf)
 140 {
 141         int nr = to_sensor_dev_attr(attr)->index;
 142         struct adt7411_data *data = dev_get_drvdata(dev);
 143         struct i2c_client *client = data->client;
 144         int val;
 145         u8 lsb_reg, lsb_shift;
 146
 147         mutex_lock(&data->update_lock);
 148         if (time_after_eq(jiffies, data->next_update)) {
 149                 val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
 150                 if (val < 0)
 151                         goto exit_unlock;
 152
 153                 if (val & ADT7411_CFG3_REF_VDD) {
 154                         val = adt7411_read_10_bit(client,
 155                                         ADT7411_REG_INT_TEMP_VDD_LSB,
 156                                         ADT7411_REG_VDD_MSB, 2);
 157                         if (val < 0)
 158                                 goto exit_unlock;
 159
 160                         data->vref_cached = val * 7000 / 1024;
 161                 } else {
 162                         data->vref_cached = 2250;
 163                 }
 164
 165                 data->next_update = jiffies + HZ;
 166         }
 167
 168         lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
 169         lsb_shift = 2 * (nr & 0x03);
 170         val = adt7411_read_10_bit(client, lsb_reg,
 171                         ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
 172         if (val < 0)
 173                 goto exit_unlock;
 174
 175         val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
 176  exit_unlock:
 177         mutex_unlock(&data->update_lock);
 178         return val;
 179 }
 180
 181 static ssize_t adt7411_show_bit(struct device *dev,
 182                                 struct device_attribute *attr, char *buf)
 183 {
 184         struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
 185         struct adt7411_data *data = dev_get_drvdata(dev);
 186         struct i2c_client *client = data->client;
 187         int ret = i2c_smbus_read_byte_data(client, attr2->index);
 188
 189         return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
 190 }
 191
 192 static ssize_t adt7411_set_bit(struct device *dev,
 193                                struct device_attribute *attr, const char *buf,
 194                                size_t count)
 195 {
 196         struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
 197         struct adt7411_data *data = dev_get_drvdata(dev);
 198         struct i2c_client *client = data->client;
 199         int ret;
 200         unsigned long flag;
 201
 202         ret = kstrtoul(buf, 0, &flag);
 203         if (ret || flag > 1)
 204                 return -EINVAL;
 205
 206         ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
 207
 208         /* force update */
 209         mutex_lock(&data->update_lock);
 210         data->next_update = jiffies;
 211         mutex_unlock(&data->update_lock);
 212
 213         return ret < 0 ? ret : count;
 214 }
 215
 216 #define ADT7411_BIT_ATTR(__name, __reg, __bit) \
 217         SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
 218         adt7411_set_bit, __bit, __reg)
 219
 220 static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
 221 static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
 222 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
 223 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
 224 static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
 225 static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
 226 static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
 227 static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
 228 static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
 229 static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
 230 static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
 231 static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
 232 static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
 233
 234 static struct attribute *adt7411_attrs[] = {
 235         &dev_attr_temp1_input.attr,
 236         &dev_attr_in0_input.attr,
 237         &sensor_dev_attr_in1_input.dev_attr.attr,
 238         &sensor_dev_attr_in2_input.dev_attr.attr,
 239         &sensor_dev_attr_in3_input.dev_attr.attr,
 240         &sensor_dev_attr_in4_input.dev_attr.attr,
 241         &sensor_dev_attr_in5_input.dev_attr.attr,
 242         &sensor_dev_attr_in6_input.dev_attr.attr,
 243         &sensor_dev_attr_in7_input.dev_attr.attr,
 244         &sensor_dev_attr_in8_input.dev_attr.attr,
 245         &sensor_dev_attr_no_average.dev_attr.attr,
 246         &sensor_dev_attr_fast_sampling.dev_attr.attr,
 247         &sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
 248         NULL
 249 };
 250
 251 ATTRIBUTE_GROUPS(adt7411);
 252
 253 static int adt7411_detect(struct i2c_client *client,
 254                           struct i2c_board_info *info)
 255 {
 256         int val;
 257
 258         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 259                 return -ENODEV;
 260
 261         val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
 262         if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
 263                 dev_dbg(&client->dev,
 264                         "Wrong manufacturer ID. Got %d, expected %d\n",
 265                         val, ADT7411_MANUFACTURER_ID);
 266                 return -ENODEV;
 267         }
 268
 269         val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
 270         if (val < 0 || val != ADT7411_DEVICE_ID) {
 271                 dev_dbg(&client->dev,
 272                         "Wrong device ID. Got %d, expected %d\n",
 273                         val, ADT7411_DEVICE_ID);
 274                 return -ENODEV;
 275         }
 276
 277         strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
 278
 279         return 0;
 280 }
 281
 282 static int adt7411_probe(struct i2c_client *client,
 283                                    const struct i2c_device_id *id)
 284 {
 285         struct device *dev = &client->dev;
 286         struct adt7411_data *data;
 287         struct device *hwmon_dev;
 288         int ret;
 289
 290         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 291         if (!data)
 292                 return -ENOMEM;
 293
 294         i2c_set_clientdata(client, data);
 295         data->client = client;
 296         mutex_init(&data->device_lock);
 297         mutex_init(&data->update_lock);
 298
 299         ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
 300                                  ADT7411_CFG1_START_MONITOR, 1);
 301         if (ret < 0)
 302                 return ret;
 303
 304         /* force update on first occasion */
 305         data->next_update = jiffies;
 306
 307         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 308                                                            data,
 309                                                            adt7411_groups);
 310         return PTR_ERR_OR_ZERO(hwmon_dev);
 311 }
 312
 313 static const struct i2c_device_id adt7411_id[] = {
 314         { "adt7411", 0 },
 315         { }
 316 };
 317 MODULE_DEVICE_TABLE(i2c, adt7411_id);
 318
 319 static struct i2c_driver adt7411_driver = {
 320         .driver         = {
 321                 .name           = "adt7411",
 322         },
 323         .probe  = adt7411_probe,
 324         .id_table = adt7411_id,
 325         .detect = adt7411_detect,
 326         .address_list = normal_i2c,
 327         .class = I2C_CLASS_HWMON,
 328 };
 329
 330 module_i2c_driver(adt7411_driver);
 331
 332 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
 333         "Wolfram Sang <w.sang@pengutronix.de>");
 334 MODULE_DESCRIPTION("ADT7411 driver");
 335 MODULE_LICENSE("GPL v2");