tpl0102.c 4.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * tpl0102.c - Support for Texas Instruments digital potentiometers
  4. *
  5. * Copyright (C) 2016, 2018
  6. * Author: Matt Ranostay <matt.ranostay@konsulko.com>
  7. *
  8. * TODO: enable/disable hi-z output control
  9. */
  10. #include <linux/module.h>
  11. #include <linux/i2c.h>
  12. #include <linux/regmap.h>
  13. #include <linux/iio/iio.h>
  14. struct tpl0102_cfg {
  15. int wipers;
  16. int avail[3];
  17. int kohms;
  18. };
  19. enum tpl0102_type {
  20. CAT5140_503,
  21. CAT5140_104,
  22. TPL0102_104,
  23. TPL0401_103,
  24. };
  25. static const struct tpl0102_cfg tpl0102_cfg[] = {
  26. /* on-semiconductor parts */
  27. [CAT5140_503] = { .wipers = 1, .avail = { 0, 1, 255 }, .kohms = 50, },
  28. [CAT5140_104] = { .wipers = 1, .avail = { 0, 1, 255 }, .kohms = 100, },
  29. /* ti parts */
  30. [TPL0102_104] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 100 },
  31. [TPL0401_103] = { .wipers = 1, .avail = { 0, 1, 127 }, .kohms = 10, },
  32. };
  33. struct tpl0102_data {
  34. struct regmap *regmap;
  35. const struct tpl0102_cfg *cfg;
  36. };
  37. static const struct regmap_config tpl0102_regmap_config = {
  38. .reg_bits = 8,
  39. .val_bits = 8,
  40. };
  41. #define TPL0102_CHANNEL(ch) { \
  42. .type = IIO_RESISTANCE, \
  43. .indexed = 1, \
  44. .output = 1, \
  45. .channel = (ch), \
  46. .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
  47. .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
  48. .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW), \
  49. }
  50. static const struct iio_chan_spec tpl0102_channels[] = {
  51. TPL0102_CHANNEL(0),
  52. TPL0102_CHANNEL(1),
  53. };
  54. static int tpl0102_read_raw(struct iio_dev *indio_dev,
  55. struct iio_chan_spec const *chan,
  56. int *val, int *val2, long mask)
  57. {
  58. struct tpl0102_data *data = iio_priv(indio_dev);
  59. switch (mask) {
  60. case IIO_CHAN_INFO_RAW: {
  61. int ret = regmap_read(data->regmap, chan->channel, val);
  62. return ret ? ret : IIO_VAL_INT;
  63. }
  64. case IIO_CHAN_INFO_SCALE:
  65. *val = 1000 * data->cfg->kohms;
  66. *val2 = data->cfg->avail[2] + 1;
  67. return IIO_VAL_FRACTIONAL;
  68. }
  69. return -EINVAL;
  70. }
  71. static int tpl0102_read_avail(struct iio_dev *indio_dev,
  72. struct iio_chan_spec const *chan,
  73. const int **vals, int *type, int *length,
  74. long mask)
  75. {
  76. struct tpl0102_data *data = iio_priv(indio_dev);
  77. switch (mask) {
  78. case IIO_CHAN_INFO_RAW:
  79. *length = ARRAY_SIZE(data->cfg->avail);
  80. *vals = data->cfg->avail;
  81. *type = IIO_VAL_INT;
  82. return IIO_AVAIL_RANGE;
  83. }
  84. return -EINVAL;
  85. }
  86. static int tpl0102_write_raw(struct iio_dev *indio_dev,
  87. struct iio_chan_spec const *chan,
  88. int val, int val2, long mask)
  89. {
  90. struct tpl0102_data *data = iio_priv(indio_dev);
  91. if (mask != IIO_CHAN_INFO_RAW)
  92. return -EINVAL;
  93. if (val > data->cfg->avail[2] || val < 0)
  94. return -EINVAL;
  95. return regmap_write(data->regmap, chan->channel, val);
  96. }
  97. static const struct iio_info tpl0102_info = {
  98. .read_raw = tpl0102_read_raw,
  99. .read_avail = tpl0102_read_avail,
  100. .write_raw = tpl0102_write_raw,
  101. };
  102. static int tpl0102_probe(struct i2c_client *client,
  103. const struct i2c_device_id *id)
  104. {
  105. struct device *dev = &client->dev;
  106. struct tpl0102_data *data;
  107. struct iio_dev *indio_dev;
  108. indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
  109. if (!indio_dev)
  110. return -ENOMEM;
  111. data = iio_priv(indio_dev);
  112. i2c_set_clientdata(client, indio_dev);
  113. data->cfg = &tpl0102_cfg[id->driver_data];
  114. data->regmap = devm_regmap_init_i2c(client, &tpl0102_regmap_config);
  115. if (IS_ERR(data->regmap)) {
  116. dev_err(dev, "regmap initialization failed\n");
  117. return PTR_ERR(data->regmap);
  118. }
  119. indio_dev->info = &tpl0102_info;
  120. indio_dev->channels = tpl0102_channels;
  121. indio_dev->num_channels = data->cfg->wipers;
  122. indio_dev->name = client->name;
  123. return devm_iio_device_register(dev, indio_dev);
  124. }
  125. static const struct i2c_device_id tpl0102_id[] = {
  126. { "cat5140-503", CAT5140_503 },
  127. { "cat5140-104", CAT5140_104 },
  128. { "tpl0102-104", TPL0102_104 },
  129. { "tpl0401-103", TPL0401_103 },
  130. {}
  131. };
  132. MODULE_DEVICE_TABLE(i2c, tpl0102_id);
  133. static struct i2c_driver tpl0102_driver = {
  134. .driver = {
  135. .name = "tpl0102",
  136. },
  137. .probe = tpl0102_probe,
  138. .id_table = tpl0102_id,
  139. };
  140. module_i2c_driver(tpl0102_driver);
  141. MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
  142. MODULE_DESCRIPTION("TPL0102 digital potentiometer");
  143. MODULE_LICENSE("GPL");