gpio.c 3.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Copyright (C) 2021 Sean Anderson <sean.anderson@seco.com>
  4. */
  5. #include <common.h>
  6. #include <dm.h>
  7. #include <log.h>
  8. #include <sysinfo.h>
  9. #include <asm/gpio.h>
  10. #include <dm/device_compat.h>
  11. /**
  12. * struct sysinfo_gpio_priv - GPIO sysinfo private data
  13. * @gpios: List of GPIOs used to detect the revision
  14. * @gpio_num: The number of GPIOs in @gpios
  15. * @revision: The revision as detected from the GPIOs.
  16. */
  17. struct sysinfo_gpio_priv {
  18. struct gpio_desc *gpios;
  19. int gpio_num, revision;
  20. };
  21. static int sysinfo_gpio_detect(struct udevice *dev)
  22. {
  23. int ret;
  24. struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
  25. ret = dm_gpio_get_values_as_int_base3(priv->gpios, priv->gpio_num);
  26. if (ret < 0)
  27. return ret;
  28. priv->revision = ret;
  29. return 0;
  30. }
  31. static int sysinfo_gpio_get_int(struct udevice *dev, int id, int *val)
  32. {
  33. struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
  34. switch (id) {
  35. case SYSINFO_ID_BOARD_MODEL:
  36. *val = priv->revision;
  37. return 0;
  38. default:
  39. return -EINVAL;
  40. };
  41. }
  42. static int sysinfo_gpio_get_str(struct udevice *dev, int id, size_t size, char *val)
  43. {
  44. struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
  45. switch (id) {
  46. case SYSINFO_ID_BOARD_MODEL: {
  47. const char *name = NULL;
  48. int i, ret;
  49. u32 revision;
  50. for (i = 0; i < priv->gpio_num; i++) {
  51. ret = dev_read_u32_index(dev, "revisions", i,
  52. &revision);
  53. if (ret) {
  54. if (ret != -EOVERFLOW)
  55. return ret;
  56. break;
  57. }
  58. if (revision == priv->revision) {
  59. ret = dev_read_string_index(dev, "names", i,
  60. &name);
  61. if (ret < 0)
  62. return ret;
  63. break;
  64. }
  65. }
  66. if (!name)
  67. name = "unknown";
  68. strncpy(val, name, size);
  69. val[size - 1] = '\0';
  70. return 0;
  71. } default:
  72. return -EINVAL;
  73. };
  74. }
  75. static const struct sysinfo_ops sysinfo_gpio_ops = {
  76. .detect = sysinfo_gpio_detect,
  77. .get_int = sysinfo_gpio_get_int,
  78. .get_str = sysinfo_gpio_get_str,
  79. };
  80. static int sysinfo_gpio_probe(struct udevice *dev)
  81. {
  82. int ret;
  83. struct sysinfo_gpio_priv *priv = dev_get_priv(dev);
  84. priv->gpio_num = gpio_get_list_count(dev, "gpios");
  85. if (priv->gpio_num < 0) {
  86. dev_err(dev, "could not get gpios length (err = %d)\n",
  87. priv->gpio_num);
  88. return priv->gpio_num;
  89. }
  90. priv->gpios = calloc(priv->gpio_num, sizeof(*priv->gpios));
  91. if (!priv->gpios) {
  92. dev_err(dev, "could not allocate memory for %d gpios\n",
  93. priv->gpio_num);
  94. return -ENOMEM;
  95. }
  96. ret = gpio_request_list_by_name(dev, "gpios", priv->gpios,
  97. priv->gpio_num, GPIOD_IS_IN);
  98. if (ret != priv->gpio_num) {
  99. dev_err(dev, "could not get gpios (err = %d)\n",
  100. priv->gpio_num);
  101. return ret;
  102. }
  103. if (!dev_read_bool(dev, "revisions") || !dev_read_bool(dev, "names")) {
  104. dev_err(dev, "revisions or names properties missing\n");
  105. return -ENOENT;
  106. }
  107. return 0;
  108. }
  109. static const struct udevice_id sysinfo_gpio_ids[] = {
  110. { .compatible = "gpio-sysinfo" },
  111. { /* sentinel */ }
  112. };
  113. U_BOOT_DRIVER(sysinfo_gpio) = {
  114. .name = "sysinfo_gpio",
  115. .id = UCLASS_SYSINFO,
  116. .of_match = sysinfo_gpio_ids,
  117. .ops = &sysinfo_gpio_ops,
  118. .priv_auto = sizeof(struct sysinfo_gpio_priv),
  119. .probe = sysinfo_gpio_probe,
  120. };