led_gpio.c 2.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Copyright (c) 2015 Google, Inc
  4. * Written by Simon Glass <sjg@chromium.org>
  5. */
  6. #include <common.h>
  7. #include <dm.h>
  8. #include <errno.h>
  9. #include <led.h>
  10. #include <asm/gpio.h>
  11. #include <dm/lists.h>
  12. struct led_gpio_priv {
  13. struct gpio_desc gpio;
  14. };
  15. static int gpio_led_set_state(struct udevice *dev, enum led_state_t state)
  16. {
  17. struct led_gpio_priv *priv = dev_get_priv(dev);
  18. int ret;
  19. if (!dm_gpio_is_valid(&priv->gpio))
  20. return -EREMOTEIO;
  21. switch (state) {
  22. case LEDST_OFF:
  23. case LEDST_ON:
  24. break;
  25. case LEDST_TOGGLE:
  26. ret = dm_gpio_get_value(&priv->gpio);
  27. if (ret < 0)
  28. return ret;
  29. state = !ret;
  30. break;
  31. default:
  32. return -ENOSYS;
  33. }
  34. return dm_gpio_set_value(&priv->gpio, state);
  35. }
  36. static enum led_state_t gpio_led_get_state(struct udevice *dev)
  37. {
  38. struct led_gpio_priv *priv = dev_get_priv(dev);
  39. int ret;
  40. if (!dm_gpio_is_valid(&priv->gpio))
  41. return -EREMOTEIO;
  42. ret = dm_gpio_get_value(&priv->gpio);
  43. if (ret < 0)
  44. return ret;
  45. return ret ? LEDST_ON : LEDST_OFF;
  46. }
  47. static int led_gpio_probe(struct udevice *dev)
  48. {
  49. struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
  50. struct led_gpio_priv *priv = dev_get_priv(dev);
  51. const char *default_state;
  52. int ret;
  53. /* Ignore the top-level LED node */
  54. if (!uc_plat->label)
  55. return 0;
  56. ret = gpio_request_by_name(dev, "gpios", 0, &priv->gpio, GPIOD_IS_OUT);
  57. if (ret)
  58. return ret;
  59. default_state = dev_read_string(dev, "default-state");
  60. if (default_state) {
  61. if (!strncmp(default_state, "on", 2))
  62. gpio_led_set_state(dev, LEDST_ON);
  63. else if (!strncmp(default_state, "off", 3))
  64. gpio_led_set_state(dev, LEDST_OFF);
  65. }
  66. return 0;
  67. }
  68. static int led_gpio_remove(struct udevice *dev)
  69. {
  70. /*
  71. * The GPIO driver may have already been removed. We will need to
  72. * address this more generally.
  73. */
  74. #ifndef CONFIG_SANDBOX
  75. struct led_gpio_priv *priv = dev_get_priv(dev);
  76. if (dm_gpio_is_valid(&priv->gpio))
  77. dm_gpio_free(dev, &priv->gpio);
  78. #endif
  79. return 0;
  80. }
  81. static int led_gpio_bind(struct udevice *parent)
  82. {
  83. struct udevice *dev;
  84. ofnode node;
  85. int ret;
  86. dev_for_each_subnode(node, parent) {
  87. struct led_uc_plat *uc_plat;
  88. const char *label;
  89. label = ofnode_read_string(node, "label");
  90. if (!label) {
  91. debug("%s: node %s has no label\n", __func__,
  92. ofnode_get_name(node));
  93. return -EINVAL;
  94. }
  95. ret = device_bind_driver_to_node(parent, "gpio_led",
  96. ofnode_get_name(node),
  97. node, &dev);
  98. if (ret)
  99. return ret;
  100. uc_plat = dev_get_uclass_platdata(dev);
  101. uc_plat->label = label;
  102. }
  103. return 0;
  104. }
  105. static const struct led_ops gpio_led_ops = {
  106. .set_state = gpio_led_set_state,
  107. .get_state = gpio_led_get_state,
  108. };
  109. static const struct udevice_id led_gpio_ids[] = {
  110. { .compatible = "gpio-leds" },
  111. { }
  112. };
  113. U_BOOT_DRIVER(led_gpio) = {
  114. .name = "gpio_led",
  115. .id = UCLASS_LED,
  116. .of_match = led_gpio_ids,
  117. .ops = &gpio_led_ops,
  118. .priv_auto_alloc_size = sizeof(struct led_gpio_priv),
  119. .bind = led_gpio_bind,
  120. .probe = led_gpio_probe,
  121. .remove = led_gpio_remove,
  122. };