drivers/iio/adc/ti-adc081c.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver
   4  *
   5  * Copyright (C) 2012 Avionic Design GmbH
   6  * Copyright (C) 2016 Intel
   7  *
   8  * Datasheets:
   9  *      http://www.ti.com/lit/ds/symlink/adc081c021.pdf
  10  *      http://www.ti.com/lit/ds/symlink/adc101c021.pdf
  11  *      http://www.ti.com/lit/ds/symlink/adc121c021.pdf
  12  *
  13  * The devices have a very similar interface and differ mostly in the number of
  14  * bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2
  15  * bits of value registers are reserved.
  16  */
  17
  18 #include <linux/err.h>
  19 #include <linux/i2c.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/acpi.h>
  23
  24 #include <linux/iio/iio.h>
  25 #include <linux/iio/buffer.h>
  26 #include <linux/iio/trigger_consumer.h>
  27 #include <linux/iio/triggered_buffer.h>
  28 #include <linux/regulator/consumer.h>
  29
  30 struct adc081c {
  31         struct i2c_client *i2c;
  32         struct regulator *ref;
  33
  34         /* 8, 10 or 12 */
  35         int bits;
  36 };
  37
  38 #define REG_CONV_RES 0x00
  39
  40 static int adc081c_read_raw(struct iio_dev *iio,
  41                             struct iio_chan_spec const *channel, int *value,
  42                             int *shift, long mask)
  43 {
  44         struct adc081c *adc = iio_priv(iio);
  45         int err;
  46
  47         switch (mask) {
  48         case IIO_CHAN_INFO_RAW:
  49                 err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
  50                 if (err < 0)
  51                         return err;
  52
  53                 *value = (err & 0xFFF) >> (12 - adc->bits);
  54                 return IIO_VAL_INT;
  55
  56         case IIO_CHAN_INFO_SCALE:
  57                 err = regulator_get_voltage(adc->ref);
  58                 if (err < 0)
  59                         return err;
  60
  61                 *value = err / 1000;
  62                 *shift = adc->bits;
  63
  64                 return IIO_VAL_FRACTIONAL_LOG2;
  65
  66         default:
  67                 break;
  68         }
  69
  70         return -EINVAL;
  71 }
  72
  73 #define ADCxx1C_CHAN(_bits) {                                   \
  74         .type = IIO_VOLTAGE,                                    \
  75         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
  76         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
  77         .scan_type = {                                          \
  78                 .sign = 'u',                                    \
  79                 .realbits = (_bits),                            \
  80                 .storagebits = 16,                              \
  81                 .shift = 12 - (_bits),                          \
  82                 .endianness = IIO_CPU,                          \
  83         },                                                      \
  84 }
  85
  86 #define DEFINE_ADCxx1C_CHANNELS(_name, _bits)                           \
  87         static const struct iio_chan_spec _name ## _channels[] = {      \
  88                 ADCxx1C_CHAN((_bits)),                                  \
  89                 IIO_CHAN_SOFT_TIMESTAMP(1),                             \
  90         };                                                              \
  91
  92 #define ADC081C_NUM_CHANNELS 2
  93
  94 struct adcxx1c_model {
  95         const struct iio_chan_spec* channels;
  96         int bits;
  97 };
  98
  99 #define ADCxx1C_MODEL(_name, _bits)                                     \
 100         {                                                               \
 101                 .channels = _name ## _channels,                         \
 102                 .bits = (_bits),                                        \
 103         }
 104
 105 DEFINE_ADCxx1C_CHANNELS(adc081c,  8);
 106 DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
 107 DEFINE_ADCxx1C_CHANNELS(adc121c, 12);
 108
 109 /* Model ids are indexes in _models array */
 110 enum adcxx1c_model_id {
 111         ADC081C = 0,
 112         ADC101C = 1,
 113         ADC121C = 2,
 114 };
 115
 116 static struct adcxx1c_model adcxx1c_models[] = {
 117         ADCxx1C_MODEL(adc081c,  8),
 118         ADCxx1C_MODEL(adc101c, 10),
 119         ADCxx1C_MODEL(adc121c, 12),
 120 };
 121
 122 static const struct iio_info adc081c_info = {
 123         .read_raw = adc081c_read_raw,
 124 };
 125
 126 static irqreturn_t adc081c_trigger_handler(int irq, void *p)
 127 {
 128         struct iio_poll_func *pf = p;
 129         struct iio_dev *indio_dev = pf->indio_dev;
 130         struct adc081c *data = iio_priv(indio_dev);
 131         u16 buf[8]; /* 2 bytes data + 6 bytes padding + 8 bytes timestamp */
 132         int ret;
 133
 134         ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
 135         if (ret < 0)
 136                 goto out;
 137         buf[0] = ret;
 138         iio_push_to_buffers_with_timestamp(indio_dev, buf,
 139                                            iio_get_time_ns(indio_dev));
 140 out:
 141         iio_trigger_notify_done(indio_dev->trig);
 142         return IRQ_HANDLED;
 143 }
 144
 145 static int adc081c_probe(struct i2c_client *client,
 146                          const struct i2c_device_id *id)
 147 {
 148         struct iio_dev *iio;
 149         struct adc081c *adc;
 150         struct adcxx1c_model *model;
 151         int err;
 152
 153         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 154                 return -EOPNOTSUPP;
 155
 156         if (ACPI_COMPANION(&client->dev)) {
 157                 const struct acpi_device_id *ad_id;
 158
 159                 ad_id = acpi_match_device(client->dev.driver->acpi_match_table,
 160                                           &client->dev);
 161                 if (!ad_id)
 162                         return -ENODEV;
 163                 model = &adcxx1c_models[ad_id->driver_data];
 164         } else {
 165                 model = &adcxx1c_models[id->driver_data];
 166         }
 167
 168         iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
 169         if (!iio)
 170                 return -ENOMEM;
 171
 172         adc = iio_priv(iio);
 173         adc->i2c = client;
 174         adc->bits = model->bits;
 175
 176         adc->ref = devm_regulator_get(&client->dev, "vref");
 177         if (IS_ERR(adc->ref))
 178                 return PTR_ERR(adc->ref);
 179
 180         err = regulator_enable(adc->ref);
 181         if (err < 0)
 182                 return err;
 183
 184         iio->dev.parent = &client->dev;
 185         iio->dev.of_node = client->dev.of_node;
 186         iio->name = dev_name(&client->dev);
 187         iio->modes = INDIO_DIRECT_MODE;
 188         iio->info = &adc081c_info;
 189
 190         iio->channels = model->channels;
 191         iio->num_channels = ADC081C_NUM_CHANNELS;
 192
 193         err = iio_triggered_buffer_setup(iio, NULL, adc081c_trigger_handler, NULL);
 194         if (err < 0) {
 195                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
 196                 goto err_regulator_disable;
 197         }
 198
 199         err = iio_device_register(iio);
 200         if (err < 0)
 201                 goto err_buffer_cleanup;
 202
 203         i2c_set_clientdata(client, iio);
 204
 205         return 0;
 206
 207 err_buffer_cleanup:
 208         iio_triggered_buffer_cleanup(iio);
 209 err_regulator_disable:
 210         regulator_disable(adc->ref);
 211
 212         return err;
 213 }
 214
 215 static int adc081c_remove(struct i2c_client *client)
 216 {
 217         struct iio_dev *iio = i2c_get_clientdata(client);
 218         struct adc081c *adc = iio_priv(iio);
 219
 220         iio_device_unregister(iio);
 221         iio_triggered_buffer_cleanup(iio);
 222         regulator_disable(adc->ref);
 223
 224         return 0;
 225 }
 226
 227 static const struct i2c_device_id adc081c_id[] = {
 228         { "adc081c", ADC081C },
 229         { "adc101c", ADC101C },
 230         { "adc121c", ADC121C },
 231         { }
 232 };
 233 MODULE_DEVICE_TABLE(i2c, adc081c_id);
 234
 235 #ifdef CONFIG_OF
 236 static const struct of_device_id adc081c_of_match[] = {
 237         { .compatible = "ti,adc081c" },
 238         { .compatible = "ti,adc101c" },
 239         { .compatible = "ti,adc121c" },
 240         { }
 241 };
 242 MODULE_DEVICE_TABLE(of, adc081c_of_match);
 243 #endif
 244
 245 #ifdef CONFIG_ACPI
 246 static const struct acpi_device_id adc081c_acpi_match[] = {
 247         { "ADC081C", ADC081C },
 248         { "ADC101C", ADC101C },
 249         { "ADC121C", ADC121C },
 250         { }
 251 };
 252 MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match);
 253 #endif
 254
 255 static struct i2c_driver adc081c_driver = {
 256         .driver = {
 257                 .name = "adc081c",
 258                 .of_match_table = of_match_ptr(adc081c_of_match),
 259                 .acpi_match_table = ACPI_PTR(adc081c_acpi_match),
 260         },
 261         .probe = adc081c_probe,
 262         .remove = adc081c_remove,
 263         .id_table = adc081c_id,
 264 };
 265 module_i2c_driver(adc081c_driver);
 266
 267 MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
 268 MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");
 269 MODULE_LICENSE("GPL v2");