leds-ariel.c 3.0 KB

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  1. // SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0-or-later
  2. /*
  3. * Dell Wyse 3020 a.k.a. "Ariel" Embedded Controller LED Driver
  4. *
  5. * Copyright (C) 2020 Lubomir Rintel
  6. */
  7. #include <linux/module.h>
  8. #include <linux/leds.h>
  9. #include <linux/regmap.h>
  10. #include <linux/of_platform.h>
  11. enum ec_index {
  12. EC_BLUE_LED = 0x01,
  13. EC_AMBER_LED = 0x02,
  14. EC_GREEN_LED = 0x03,
  15. };
  16. enum {
  17. EC_LED_OFF = 0x00,
  18. EC_LED_STILL = 0x01,
  19. EC_LED_FADE = 0x02,
  20. EC_LED_BLINK = 0x03,
  21. };
  22. struct ariel_led {
  23. struct regmap *ec_ram;
  24. enum ec_index ec_index;
  25. struct led_classdev led_cdev;
  26. };
  27. #define led_cdev_to_ariel_led(c) container_of(c, struct ariel_led, led_cdev)
  28. static enum led_brightness ariel_led_get(struct led_classdev *led_cdev)
  29. {
  30. struct ariel_led *led = led_cdev_to_ariel_led(led_cdev);
  31. unsigned int led_status = 0;
  32. if (regmap_read(led->ec_ram, led->ec_index, &led_status))
  33. return LED_OFF;
  34. if (led_status == EC_LED_STILL)
  35. return LED_FULL;
  36. else
  37. return LED_OFF;
  38. }
  39. static void ariel_led_set(struct led_classdev *led_cdev,
  40. enum led_brightness brightness)
  41. {
  42. struct ariel_led *led = led_cdev_to_ariel_led(led_cdev);
  43. if (brightness == LED_OFF)
  44. regmap_write(led->ec_ram, led->ec_index, EC_LED_OFF);
  45. else
  46. regmap_write(led->ec_ram, led->ec_index, EC_LED_STILL);
  47. }
  48. static int ariel_blink_set(struct led_classdev *led_cdev,
  49. unsigned long *delay_on, unsigned long *delay_off)
  50. {
  51. struct ariel_led *led = led_cdev_to_ariel_led(led_cdev);
  52. if (*delay_on == 0 && *delay_off == 0)
  53. return -EINVAL;
  54. if (*delay_on == 0) {
  55. regmap_write(led->ec_ram, led->ec_index, EC_LED_OFF);
  56. } else if (*delay_off == 0) {
  57. regmap_write(led->ec_ram, led->ec_index, EC_LED_STILL);
  58. } else {
  59. *delay_on = 500;
  60. *delay_off = 500;
  61. regmap_write(led->ec_ram, led->ec_index, EC_LED_BLINK);
  62. }
  63. return 0;
  64. }
  65. #define NLEDS 3
  66. static int ariel_led_probe(struct platform_device *pdev)
  67. {
  68. struct device *dev = &pdev->dev;
  69. struct ariel_led *leds;
  70. struct regmap *ec_ram;
  71. int ret;
  72. int i;
  73. ec_ram = dev_get_regmap(dev->parent, "ec_ram");
  74. if (!ec_ram)
  75. return -ENODEV;
  76. leds = devm_kcalloc(dev, NLEDS, sizeof(*leds), GFP_KERNEL);
  77. if (!leds)
  78. return -ENOMEM;
  79. leds[0].ec_index = EC_BLUE_LED;
  80. leds[0].led_cdev.name = "blue:power",
  81. leds[0].led_cdev.default_trigger = "default-on";
  82. leds[1].ec_index = EC_AMBER_LED;
  83. leds[1].led_cdev.name = "amber:status",
  84. leds[2].ec_index = EC_GREEN_LED;
  85. leds[2].led_cdev.name = "green:status",
  86. leds[2].led_cdev.default_trigger = "default-on";
  87. for (i = 0; i < NLEDS; i++) {
  88. leds[i].ec_ram = ec_ram;
  89. leds[i].led_cdev.brightness_get = ariel_led_get;
  90. leds[i].led_cdev.brightness_set = ariel_led_set;
  91. leds[i].led_cdev.blink_set = ariel_blink_set;
  92. ret = devm_led_classdev_register(dev, &leds[i].led_cdev);
  93. if (ret)
  94. return ret;
  95. }
  96. return 0;
  97. }
  98. static struct platform_driver ariel_led_driver = {
  99. .probe = ariel_led_probe,
  100. .driver = {
  101. .name = "dell-wyse-ariel-led",
  102. },
  103. };
  104. module_platform_driver(ariel_led_driver);
  105. MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
  106. MODULE_DESCRIPTION("Dell Wyse 3020 Status LEDs Driver");
  107. MODULE_LICENSE("Dual BSD/GPL");