gpio_keys.c 3.4 KB

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  1. /*
  2. * Driver for keys on GPIO lines capable of generating interrupts.
  3. *
  4. * Copyright 2005 Phil Blundell
  5. *
  6. * This program is free software; you can redistribute it and/or modify
  7. * it under the terms of the GNU General Public License version 2 as
  8. * published by the Free Software Foundation.
  9. */
  10. #include <linux/module.h>
  11. #include <linux/version.h>
  12. #include <linux/init.h>
  13. #include <linux/fs.h>
  14. #include <linux/interrupt.h>
  15. #include <linux/irq.h>
  16. #include <linux/sched.h>
  17. #include <linux/pm.h>
  18. #include <linux/sysctl.h>
  19. #include <linux/proc_fs.h>
  20. #include <linux/delay.h>
  21. #include <linux/platform_device.h>
  22. #include <linux/input.h>
  23. #include <linux/irq.h>
  24. #include <linux/gpio_keys.h>
  25. #include <asm/gpio.h>
  26. static irqreturn_t gpio_keys_isr(int irq, void *dev_id)
  27. {
  28. int i;
  29. struct platform_device *pdev = dev_id;
  30. struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
  31. struct input_dev *input = platform_get_drvdata(pdev);
  32. for (i = 0; i < pdata->nbuttons; i++) {
  33. int gpio = pdata->buttons[i].gpio;
  34. if (irq == gpio_to_irq(gpio)) {
  35. int state = (gpio_get_value(gpio) ? 1 : 0) ^ (pdata->buttons[i].active_low);
  36. input_report_key(input, pdata->buttons[i].keycode, state);
  37. input_sync(input);
  38. }
  39. }
  40. return IRQ_HANDLED;
  41. }
  42. static int __devinit gpio_keys_probe(struct platform_device *pdev)
  43. {
  44. struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
  45. struct input_dev *input;
  46. int i, error;
  47. input = input_allocate_device();
  48. if (!input)
  49. return -ENOMEM;
  50. platform_set_drvdata(pdev, input);
  51. input->evbit[0] = BIT(EV_KEY);
  52. input->name = pdev->name;
  53. input->phys = "gpio-keys/input0";
  54. input->cdev.dev = &pdev->dev;
  55. input->private = pdata;
  56. input->id.bustype = BUS_HOST;
  57. input->id.vendor = 0x0001;
  58. input->id.product = 0x0001;
  59. input->id.version = 0x0100;
  60. for (i = 0; i < pdata->nbuttons; i++) {
  61. int code = pdata->buttons[i].keycode;
  62. int irq = gpio_to_irq(pdata->buttons[i].gpio);
  63. set_irq_type(irq, IRQ_TYPE_EDGE_BOTH);
  64. error = request_irq(irq, gpio_keys_isr, IRQF_SAMPLE_RANDOM,
  65. pdata->buttons[i].desc ? pdata->buttons[i].desc : "gpio_keys",
  66. pdev);
  67. if (error) {
  68. printk(KERN_ERR "gpio-keys: unable to claim irq %d; error %d\n",
  69. irq, error);
  70. goto fail;
  71. }
  72. set_bit(code, input->keybit);
  73. }
  74. error = input_register_device(input);
  75. if (error) {
  76. printk(KERN_ERR "Unable to register gpio-keys input device\n");
  77. goto fail;
  78. }
  79. return 0;
  80. fail:
  81. for (i = i - 1; i >= 0; i--)
  82. free_irq(gpio_to_irq(pdata->buttons[i].gpio), pdev);
  83. input_free_device(input);
  84. return error;
  85. }
  86. static int __devexit gpio_keys_remove(struct platform_device *pdev)
  87. {
  88. struct gpio_keys_platform_data *pdata = pdev->dev.platform_data;
  89. struct input_dev *input = platform_get_drvdata(pdev);
  90. int i;
  91. for (i = 0; i < pdata->nbuttons; i++) {
  92. int irq = gpio_to_irq(pdata->buttons[i].gpio);
  93. free_irq(irq, pdev);
  94. }
  95. input_unregister_device(input);
  96. return 0;
  97. }
  98. struct platform_driver gpio_keys_device_driver = {
  99. .probe = gpio_keys_probe,
  100. .remove = __devexit_p(gpio_keys_remove),
  101. .driver = {
  102. .name = "gpio-keys",
  103. }
  104. };
  105. static int __init gpio_keys_init(void)
  106. {
  107. return platform_driver_register(&gpio_keys_device_driver);
  108. }
  109. static void __exit gpio_keys_exit(void)
  110. {
  111. platform_driver_unregister(&gpio_keys_device_driver);
  112. }
  113. module_init(gpio_keys_init);
  114. module_exit(gpio_keys_exit);
  115. MODULE_LICENSE("GPL");
  116. MODULE_AUTHOR("Phil Blundell <pb@handhelds.org>");
  117. MODULE_DESCRIPTION("Keyboard driver for CPU GPIOs");