ti-adc081c.c 5.7 KB

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  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. * https://www.ti.com/lit/ds/symlink/adc081c021.pdf
  10. * https://www.ti.com/lit/ds/symlink/adc101c021.pdf
  11. * https://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. #include <linux/err.h>
  18. #include <linux/i2c.h>
  19. #include <linux/module.h>
  20. #include <linux/mod_devicetable.h>
  21. #include <linux/property.h>
  22. #include <linux/iio/iio.h>
  23. #include <linux/iio/buffer.h>
  24. #include <linux/iio/trigger_consumer.h>
  25. #include <linux/iio/triggered_buffer.h>
  26. #include <linux/regulator/consumer.h>
  27. struct adc081c {
  28. struct i2c_client *i2c;
  29. struct regulator *ref;
  30. /* 8, 10 or 12 */
  31. int bits;
  32. /* Ensure natural alignment of buffer elements */
  33. struct {
  34. u16 channel;
  35. s64 ts __aligned(8);
  36. } scan;
  37. };
  38. #define REG_CONV_RES 0x00
  39. static int adc081c_read_raw(struct iio_dev *iio,
  40. struct iio_chan_spec const *channel, int *value,
  41. int *shift, long mask)
  42. {
  43. struct adc081c *adc = iio_priv(iio);
  44. int err;
  45. switch (mask) {
  46. case IIO_CHAN_INFO_RAW:
  47. err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
  48. if (err < 0)
  49. return err;
  50. *value = (err & 0xFFF) >> (12 - adc->bits);
  51. return IIO_VAL_INT;
  52. case IIO_CHAN_INFO_SCALE:
  53. err = regulator_get_voltage(adc->ref);
  54. if (err < 0)
  55. return err;
  56. *value = err / 1000;
  57. *shift = adc->bits;
  58. return IIO_VAL_FRACTIONAL_LOG2;
  59. default:
  60. break;
  61. }
  62. return -EINVAL;
  63. }
  64. #define ADCxx1C_CHAN(_bits) { \
  65. .type = IIO_VOLTAGE, \
  66. .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
  67. .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
  68. .scan_type = { \
  69. .sign = 'u', \
  70. .realbits = (_bits), \
  71. .storagebits = 16, \
  72. .shift = 12 - (_bits), \
  73. .endianness = IIO_CPU, \
  74. }, \
  75. }
  76. #define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \
  77. static const struct iio_chan_spec _name ## _channels[] = { \
  78. ADCxx1C_CHAN((_bits)), \
  79. IIO_CHAN_SOFT_TIMESTAMP(1), \
  80. }; \
  81. #define ADC081C_NUM_CHANNELS 2
  82. struct adcxx1c_model {
  83. const struct iio_chan_spec* channels;
  84. int bits;
  85. };
  86. #define ADCxx1C_MODEL(_name, _bits) \
  87. { \
  88. .channels = _name ## _channels, \
  89. .bits = (_bits), \
  90. }
  91. DEFINE_ADCxx1C_CHANNELS(adc081c, 8);
  92. DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
  93. DEFINE_ADCxx1C_CHANNELS(adc121c, 12);
  94. /* Model ids are indexes in _models array */
  95. enum adcxx1c_model_id {
  96. ADC081C = 0,
  97. ADC101C = 1,
  98. ADC121C = 2,
  99. };
  100. static struct adcxx1c_model adcxx1c_models[] = {
  101. ADCxx1C_MODEL(adc081c, 8),
  102. ADCxx1C_MODEL(adc101c, 10),
  103. ADCxx1C_MODEL(adc121c, 12),
  104. };
  105. static const struct iio_info adc081c_info = {
  106. .read_raw = adc081c_read_raw,
  107. };
  108. static irqreturn_t adc081c_trigger_handler(int irq, void *p)
  109. {
  110. struct iio_poll_func *pf = p;
  111. struct iio_dev *indio_dev = pf->indio_dev;
  112. struct adc081c *data = iio_priv(indio_dev);
  113. int ret;
  114. ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
  115. if (ret < 0)
  116. goto out;
  117. data->scan.channel = ret;
  118. iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
  119. iio_get_time_ns(indio_dev));
  120. out:
  121. iio_trigger_notify_done(indio_dev->trig);
  122. return IRQ_HANDLED;
  123. }
  124. static void adc081c_reg_disable(void *reg)
  125. {
  126. regulator_disable(reg);
  127. }
  128. static int adc081c_probe(struct i2c_client *client,
  129. const struct i2c_device_id *id)
  130. {
  131. struct iio_dev *iio;
  132. struct adc081c *adc;
  133. const struct adcxx1c_model *model;
  134. int err;
  135. if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
  136. return -EOPNOTSUPP;
  137. if (dev_fwnode(&client->dev))
  138. model = device_get_match_data(&client->dev);
  139. else
  140. model = &adcxx1c_models[id->driver_data];
  141. iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
  142. if (!iio)
  143. return -ENOMEM;
  144. adc = iio_priv(iio);
  145. adc->i2c = client;
  146. adc->bits = model->bits;
  147. adc->ref = devm_regulator_get(&client->dev, "vref");
  148. if (IS_ERR(adc->ref))
  149. return PTR_ERR(adc->ref);
  150. err = regulator_enable(adc->ref);
  151. if (err < 0)
  152. return err;
  153. err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable,
  154. adc->ref);
  155. if (err)
  156. return err;
  157. iio->name = dev_name(&client->dev);
  158. iio->modes = INDIO_DIRECT_MODE;
  159. iio->info = &adc081c_info;
  160. iio->channels = model->channels;
  161. iio->num_channels = ADC081C_NUM_CHANNELS;
  162. err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL,
  163. adc081c_trigger_handler, NULL);
  164. if (err < 0) {
  165. dev_err(&client->dev, "iio triggered buffer setup failed\n");
  166. return err;
  167. }
  168. return devm_iio_device_register(&client->dev, iio);
  169. }
  170. static const struct i2c_device_id adc081c_id[] = {
  171. { "adc081c", ADC081C },
  172. { "adc101c", ADC101C },
  173. { "adc121c", ADC121C },
  174. { }
  175. };
  176. MODULE_DEVICE_TABLE(i2c, adc081c_id);
  177. static const struct acpi_device_id adc081c_acpi_match[] = {
  178. /* Used on some AAEON boards */
  179. { "ADC081C", (kernel_ulong_t)&adcxx1c_models[ADC081C] },
  180. { }
  181. };
  182. MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match);
  183. static const struct of_device_id adc081c_of_match[] = {
  184. { .compatible = "ti,adc081c", .data = &adcxx1c_models[ADC081C] },
  185. { .compatible = "ti,adc101c", .data = &adcxx1c_models[ADC101C] },
  186. { .compatible = "ti,adc121c", .data = &adcxx1c_models[ADC121C] },
  187. { }
  188. };
  189. MODULE_DEVICE_TABLE(of, adc081c_of_match);
  190. static struct i2c_driver adc081c_driver = {
  191. .driver = {
  192. .name = "adc081c",
  193. .of_match_table = adc081c_of_match,
  194. .acpi_match_table = adc081c_acpi_match,
  195. },
  196. .probe = adc081c_probe,
  197. .id_table = adc081c_id,
  198. };
  199. module_i2c_driver(adc081c_driver);
  200. MODULE_AUTHOR("Thierry Reding <[email protected]>");
  201. MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");
  202. MODULE_LICENSE("GPL v2");