rfkill-gpio.c 4.0 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173
  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Copyright (c) 2011, NVIDIA Corporation.
  4. */
  5. #include <linux/init.h>
  6. #include <linux/kernel.h>
  7. #include <linux/module.h>
  8. #include <linux/mod_devicetable.h>
  9. #include <linux/rfkill.h>
  10. #include <linux/platform_device.h>
  11. #include <linux/clk.h>
  12. #include <linux/slab.h>
  13. #include <linux/acpi.h>
  14. #include <linux/gpio/consumer.h>
  15. struct rfkill_gpio_data {
  16. const char *name;
  17. enum rfkill_type type;
  18. struct gpio_desc *reset_gpio;
  19. struct gpio_desc *shutdown_gpio;
  20. struct rfkill *rfkill_dev;
  21. struct clk *clk;
  22. bool clk_enabled;
  23. };
  24. static int rfkill_gpio_set_power(void *data, bool blocked)
  25. {
  26. struct rfkill_gpio_data *rfkill = data;
  27. if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled)
  28. clk_enable(rfkill->clk);
  29. gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
  30. gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
  31. if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
  32. clk_disable(rfkill->clk);
  33. rfkill->clk_enabled = !blocked;
  34. return 0;
  35. }
  36. static const struct rfkill_ops rfkill_gpio_ops = {
  37. .set_block = rfkill_gpio_set_power,
  38. };
  39. static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
  40. static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
  41. static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
  42. { "reset-gpios", &reset_gpios, 1 },
  43. { "shutdown-gpios", &shutdown_gpios, 1 },
  44. { },
  45. };
  46. static int rfkill_gpio_acpi_probe(struct device *dev,
  47. struct rfkill_gpio_data *rfkill)
  48. {
  49. const struct acpi_device_id *id;
  50. id = acpi_match_device(dev->driver->acpi_match_table, dev);
  51. if (!id)
  52. return -ENODEV;
  53. rfkill->type = (unsigned)id->driver_data;
  54. return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);
  55. }
  56. static int rfkill_gpio_probe(struct platform_device *pdev)
  57. {
  58. struct rfkill_gpio_data *rfkill;
  59. struct gpio_desc *gpio;
  60. const char *type_name;
  61. int ret;
  62. rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
  63. if (!rfkill)
  64. return -ENOMEM;
  65. device_property_read_string(&pdev->dev, "name", &rfkill->name);
  66. device_property_read_string(&pdev->dev, "type", &type_name);
  67. if (!rfkill->name)
  68. rfkill->name = dev_name(&pdev->dev);
  69. rfkill->type = rfkill_find_type(type_name);
  70. if (ACPI_HANDLE(&pdev->dev)) {
  71. ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
  72. if (ret)
  73. return ret;
  74. }
  75. rfkill->clk = devm_clk_get(&pdev->dev, NULL);
  76. gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
  77. if (IS_ERR(gpio))
  78. return PTR_ERR(gpio);
  79. rfkill->reset_gpio = gpio;
  80. gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_OUT_LOW);
  81. if (IS_ERR(gpio))
  82. return PTR_ERR(gpio);
  83. rfkill->shutdown_gpio = gpio;
  84. /* Make sure at-least one GPIO is defined for this instance */
  85. if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
  86. dev_err(&pdev->dev, "invalid platform data\n");
  87. return -EINVAL;
  88. }
  89. rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
  90. rfkill->type, &rfkill_gpio_ops,
  91. rfkill);
  92. if (!rfkill->rfkill_dev)
  93. return -ENOMEM;
  94. ret = rfkill_register(rfkill->rfkill_dev);
  95. if (ret < 0)
  96. goto err_destroy;
  97. platform_set_drvdata(pdev, rfkill);
  98. dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
  99. return 0;
  100. err_destroy:
  101. rfkill_destroy(rfkill->rfkill_dev);
  102. return ret;
  103. }
  104. static int rfkill_gpio_remove(struct platform_device *pdev)
  105. {
  106. struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
  107. rfkill_unregister(rfkill->rfkill_dev);
  108. rfkill_destroy(rfkill->rfkill_dev);
  109. return 0;
  110. }
  111. #ifdef CONFIG_ACPI
  112. static const struct acpi_device_id rfkill_acpi_match[] = {
  113. { "BCM4752", RFKILL_TYPE_GPS },
  114. { "LNV4752", RFKILL_TYPE_GPS },
  115. { },
  116. };
  117. MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
  118. #endif
  119. static struct platform_driver rfkill_gpio_driver = {
  120. .probe = rfkill_gpio_probe,
  121. .remove = rfkill_gpio_remove,
  122. .driver = {
  123. .name = "rfkill_gpio",
  124. .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
  125. },
  126. };
  127. module_platform_driver(rfkill_gpio_driver);
  128. MODULE_DESCRIPTION("gpio rfkill");
  129. MODULE_AUTHOR("NVIDIA");
  130. MODULE_LICENSE("GPL");