ms5611_i2c.c 3.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * MS5611 pressure and temperature sensor driver (I2C bus)
  4. *
  5. * Copyright (c) Tomasz Duszynski <[email protected]>
  6. *
  7. * 7-bit I2C slave addresses:
  8. *
  9. * 0x77 (CSB pin low)
  10. * 0x76 (CSB pin high)
  11. *
  12. */
  13. #include <linux/delay.h>
  14. #include <linux/i2c.h>
  15. #include <linux/module.h>
  16. #include <linux/mod_devicetable.h>
  17. #include <asm/unaligned.h>
  18. #include "ms5611.h"
  19. static int ms5611_i2c_reset(struct ms5611_state *st)
  20. {
  21. return i2c_smbus_write_byte(st->client, MS5611_RESET);
  22. }
  23. static int ms5611_i2c_read_prom_word(struct ms5611_state *st, int index,
  24. u16 *word)
  25. {
  26. int ret;
  27. ret = i2c_smbus_read_word_swapped(st->client,
  28. MS5611_READ_PROM_WORD + (index << 1));
  29. if (ret < 0)
  30. return ret;
  31. *word = ret;
  32. return 0;
  33. }
  34. static int ms5611_i2c_read_adc(struct ms5611_state *st, s32 *val)
  35. {
  36. int ret;
  37. u8 buf[3];
  38. ret = i2c_smbus_read_i2c_block_data(st->client, MS5611_READ_ADC,
  39. 3, buf);
  40. if (ret < 0)
  41. return ret;
  42. *val = get_unaligned_be24(&buf[0]);
  43. return 0;
  44. }
  45. static int ms5611_i2c_read_adc_temp_and_pressure(struct ms5611_state *st,
  46. s32 *temp, s32 *pressure)
  47. {
  48. int ret;
  49. const struct ms5611_osr *osr = st->temp_osr;
  50. ret = i2c_smbus_write_byte(st->client, osr->cmd);
  51. if (ret < 0)
  52. return ret;
  53. usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  54. ret = ms5611_i2c_read_adc(st, temp);
  55. if (ret < 0)
  56. return ret;
  57. osr = st->pressure_osr;
  58. ret = i2c_smbus_write_byte(st->client, osr->cmd);
  59. if (ret < 0)
  60. return ret;
  61. usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  62. return ms5611_i2c_read_adc(st, pressure);
  63. }
  64. static int ms5611_i2c_probe(struct i2c_client *client,
  65. const struct i2c_device_id *id)
  66. {
  67. struct ms5611_state *st;
  68. struct iio_dev *indio_dev;
  69. if (!i2c_check_functionality(client->adapter,
  70. I2C_FUNC_SMBUS_WRITE_BYTE |
  71. I2C_FUNC_SMBUS_READ_WORD_DATA |
  72. I2C_FUNC_SMBUS_READ_I2C_BLOCK))
  73. return -EOPNOTSUPP;
  74. indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
  75. if (!indio_dev)
  76. return -ENOMEM;
  77. st = iio_priv(indio_dev);
  78. i2c_set_clientdata(client, indio_dev);
  79. st->reset = ms5611_i2c_reset;
  80. st->read_prom_word = ms5611_i2c_read_prom_word;
  81. st->read_adc_temp_and_pressure = ms5611_i2c_read_adc_temp_and_pressure;
  82. st->client = client;
  83. return ms5611_probe(indio_dev, &client->dev, id->name, id->driver_data);
  84. }
  85. static void ms5611_i2c_remove(struct i2c_client *client)
  86. {
  87. ms5611_remove(i2c_get_clientdata(client));
  88. }
  89. static const struct of_device_id ms5611_i2c_matches[] = {
  90. { .compatible = "meas,ms5611" },
  91. { .compatible = "meas,ms5607" },
  92. { }
  93. };
  94. MODULE_DEVICE_TABLE(of, ms5611_i2c_matches);
  95. static const struct i2c_device_id ms5611_id[] = {
  96. { "ms5611", MS5611 },
  97. { "ms5607", MS5607 },
  98. { }
  99. };
  100. MODULE_DEVICE_TABLE(i2c, ms5611_id);
  101. static struct i2c_driver ms5611_driver = {
  102. .driver = {
  103. .name = "ms5611",
  104. .of_match_table = ms5611_i2c_matches,
  105. },
  106. .id_table = ms5611_id,
  107. .probe = ms5611_i2c_probe,
  108. .remove = ms5611_i2c_remove,
  109. };
  110. module_i2c_driver(ms5611_driver);
  111. MODULE_AUTHOR("Tomasz Duszynski <[email protected]>");
  112. MODULE_DESCRIPTION("MS5611 i2c driver");
  113. MODULE_LICENSE("GPL v2");
  114. MODULE_IMPORT_NS(IIO_MS5611);