ms5611_spi.c 3.2 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * MS5611 pressure and temperature sensor driver (SPI bus)
  4. *
  5. * Copyright (c) Tomasz Duszynski <[email protected]>
  6. *
  7. */
  8. #include <linux/delay.h>
  9. #include <linux/module.h>
  10. #include <linux/spi/spi.h>
  11. #include <linux/mod_devicetable.h>
  12. #include <asm/unaligned.h>
  13. #include "ms5611.h"
  14. static int ms5611_spi_reset(struct ms5611_state *st)
  15. {
  16. u8 cmd = MS5611_RESET;
  17. return spi_write_then_read(st->client, &cmd, 1, NULL, 0);
  18. }
  19. static int ms5611_spi_read_prom_word(struct ms5611_state *st, int index,
  20. u16 *word)
  21. {
  22. int ret;
  23. ret = spi_w8r16be(st->client, MS5611_READ_PROM_WORD + (index << 1));
  24. if (ret < 0)
  25. return ret;
  26. *word = ret;
  27. return 0;
  28. }
  29. static int ms5611_spi_read_adc(struct ms5611_state *st, s32 *val)
  30. {
  31. int ret;
  32. u8 buf[3] = { MS5611_READ_ADC };
  33. ret = spi_write_then_read(st->client, buf, 1, buf, 3);
  34. if (ret < 0)
  35. return ret;
  36. *val = get_unaligned_be24(&buf[0]);
  37. return 0;
  38. }
  39. static int ms5611_spi_read_adc_temp_and_pressure(struct ms5611_state *st,
  40. s32 *temp, s32 *pressure)
  41. {
  42. int ret;
  43. const struct ms5611_osr *osr = st->temp_osr;
  44. /*
  45. * Warning: &osr->cmd MUST be aligned on a word boundary since used as
  46. * 2nd argument (void*) of spi_write_then_read.
  47. */
  48. ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
  49. if (ret < 0)
  50. return ret;
  51. usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  52. ret = ms5611_spi_read_adc(st, temp);
  53. if (ret < 0)
  54. return ret;
  55. osr = st->pressure_osr;
  56. ret = spi_write_then_read(st->client, &osr->cmd, 1, NULL, 0);
  57. if (ret < 0)
  58. return ret;
  59. usleep_range(osr->conv_usec, osr->conv_usec + (osr->conv_usec / 10UL));
  60. return ms5611_spi_read_adc(st, pressure);
  61. }
  62. static int ms5611_spi_probe(struct spi_device *spi)
  63. {
  64. int ret;
  65. struct ms5611_state *st;
  66. struct iio_dev *indio_dev;
  67. indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
  68. if (!indio_dev)
  69. return -ENOMEM;
  70. spi_set_drvdata(spi, indio_dev);
  71. spi->mode = SPI_MODE_0;
  72. spi->max_speed_hz = min(spi->max_speed_hz, 20000000U);
  73. spi->bits_per_word = 8;
  74. ret = spi_setup(spi);
  75. if (ret < 0)
  76. return ret;
  77. st = iio_priv(indio_dev);
  78. st->reset = ms5611_spi_reset;
  79. st->read_prom_word = ms5611_spi_read_prom_word;
  80. st->read_adc_temp_and_pressure = ms5611_spi_read_adc_temp_and_pressure;
  81. st->client = spi;
  82. return ms5611_probe(indio_dev, &spi->dev, spi_get_device_id(spi)->name,
  83. spi_get_device_id(spi)->driver_data);
  84. }
  85. static void ms5611_spi_remove(struct spi_device *spi)
  86. {
  87. ms5611_remove(spi_get_drvdata(spi));
  88. }
  89. static const struct of_device_id ms5611_spi_matches[] = {
  90. { .compatible = "meas,ms5611" },
  91. { .compatible = "meas,ms5607" },
  92. { }
  93. };
  94. MODULE_DEVICE_TABLE(of, ms5611_spi_matches);
  95. static const struct spi_device_id ms5611_id[] = {
  96. { "ms5611", MS5611 },
  97. { "ms5607", MS5607 },
  98. { }
  99. };
  100. MODULE_DEVICE_TABLE(spi, ms5611_id);
  101. static struct spi_driver ms5611_driver = {
  102. .driver = {
  103. .name = "ms5611",
  104. .of_match_table = ms5611_spi_matches
  105. },
  106. .id_table = ms5611_id,
  107. .probe = ms5611_spi_probe,
  108. .remove = ms5611_spi_remove,
  109. };
  110. module_spi_driver(ms5611_driver);
  111. MODULE_AUTHOR("Tomasz Duszynski <[email protected]>");
  112. MODULE_DESCRIPTION("MS5611 spi driver");
  113. MODULE_LICENSE("GPL v2");
  114. MODULE_IMPORT_NS(IIO_MS5611);