sy7636a-hwmon.c 2.4 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Functions to access SY3686A power management chip temperature
  4. *
  5. * Copyright (C) 2021 reMarkable AS - http://www.remarkable.com/
  6. *
  7. * Authors: Lars Ivar Miljeteig <[email protected]>
  8. * Alistair Francis <[email protected]>
  9. */
  10. #include <linux/err.h>
  11. #include <linux/hwmon.h>
  12. #include <linux/init.h>
  13. #include <linux/module.h>
  14. #include <linux/platform_device.h>
  15. #include <linux/regmap.h>
  16. #include <linux/regulator/machine.h>
  17. #include <linux/mfd/sy7636a.h>
  18. static int sy7636a_read(struct device *dev, enum hwmon_sensor_types type,
  19. u32 attr, int channel, long *temp)
  20. {
  21. struct regmap *regmap = dev_get_drvdata(dev);
  22. int ret, reg_val;
  23. ret = regmap_read(regmap,
  24. SY7636A_REG_TERMISTOR_READOUT, &reg_val);
  25. if (ret)
  26. return ret;
  27. *temp = reg_val * 1000;
  28. return 0;
  29. }
  30. static umode_t sy7636a_is_visible(const void *data,
  31. enum hwmon_sensor_types type,
  32. u32 attr, int channel)
  33. {
  34. if (type != hwmon_temp)
  35. return 0;
  36. if (attr != hwmon_temp_input)
  37. return 0;
  38. return 0444;
  39. }
  40. static const struct hwmon_ops sy7636a_hwmon_ops = {
  41. .is_visible = sy7636a_is_visible,
  42. .read = sy7636a_read,
  43. };
  44. static const struct hwmon_channel_info *sy7636a_info[] = {
  45. HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
  46. HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
  47. NULL
  48. };
  49. static const struct hwmon_chip_info sy7636a_chip_info = {
  50. .ops = &sy7636a_hwmon_ops,
  51. .info = sy7636a_info,
  52. };
  53. static int sy7636a_sensor_probe(struct platform_device *pdev)
  54. {
  55. struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);
  56. struct regulator *regulator;
  57. struct device *hwmon_dev;
  58. int err;
  59. if (!regmap)
  60. return -EPROBE_DEFER;
  61. regulator = devm_regulator_get(&pdev->dev, "vcom");
  62. if (IS_ERR(regulator))
  63. return PTR_ERR(regulator);
  64. err = regulator_enable(regulator);
  65. if (err)
  66. return err;
  67. hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
  68. "sy7636a_temperature", regmap,
  69. &sy7636a_chip_info, NULL);
  70. if (IS_ERR(hwmon_dev)) {
  71. err = PTR_ERR(hwmon_dev);
  72. dev_err(&pdev->dev, "Unable to register hwmon device, returned %d\n", err);
  73. return err;
  74. }
  75. return 0;
  76. }
  77. static struct platform_driver sy7636a_sensor_driver = {
  78. .probe = sy7636a_sensor_probe,
  79. .driver = {
  80. .name = "sy7636a-temperature",
  81. },
  82. };
  83. module_platform_driver(sy7636a_sensor_driver);
  84. MODULE_DESCRIPTION("SY7636A sensor driver");
  85. MODULE_LICENSE("GPL");