iio-trig-interrupt.c 2.8 KB

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  1. /*
  2. * Industrial I/O - generic interrupt based trigger support
  3. *
  4. * Copyright (c) 2008-2013 Jonathan Cameron
  5. *
  6. * This program is free software; you can redistribute it and/or modify it
  7. * under the terms of the GNU General Public License version 2 as published by
  8. * the Free Software Foundation.
  9. */
  10. #include <linux/kernel.h>
  11. #include <linux/module.h>
  12. #include <linux/platform_device.h>
  13. #include <linux/interrupt.h>
  14. #include <linux/slab.h>
  15. #include <linux/iio/iio.h>
  16. #include <linux/iio/trigger.h>
  17. struct iio_interrupt_trigger_info {
  18. unsigned int irq;
  19. };
  20. static irqreturn_t iio_interrupt_trigger_poll(int irq, void *private)
  21. {
  22. /* Timestamp not currently provided */
  23. iio_trigger_poll(private, 0);
  24. return IRQ_HANDLED;
  25. }
  26. static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
  27. .owner = THIS_MODULE,
  28. };
  29. static int iio_interrupt_trigger_probe(struct platform_device *pdev)
  30. {
  31. struct iio_interrupt_trigger_info *trig_info;
  32. struct iio_trigger *trig;
  33. unsigned long irqflags;
  34. struct resource *irq_res;
  35. int irq, ret = 0;
  36. irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
  37. if (irq_res == NULL)
  38. return -ENODEV;
  39. irqflags = (irq_res->flags & IRQF_TRIGGER_MASK) | IRQF_SHARED;
  40. irq = irq_res->start;
  41. trig = iio_trigger_alloc("irqtrig%d", irq);
  42. if (!trig) {
  43. ret = -ENOMEM;
  44. goto error_ret;
  45. }
  46. trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
  47. if (!trig_info) {
  48. ret = -ENOMEM;
  49. goto error_put_trigger;
  50. }
  51. iio_trigger_set_drvdata(trig, trig_info);
  52. trig_info->irq = irq;
  53. trig->ops = &iio_interrupt_trigger_ops;
  54. ret = request_irq(irq, iio_interrupt_trigger_poll,
  55. irqflags, trig->name, trig);
  56. if (ret) {
  57. dev_err(&pdev->dev,
  58. "request IRQ-%d failed", irq);
  59. goto error_free_trig_info;
  60. }
  61. ret = iio_trigger_register(trig);
  62. if (ret)
  63. goto error_release_irq;
  64. platform_set_drvdata(pdev, trig);
  65. return 0;
  66. /* First clean up the partly allocated trigger */
  67. error_release_irq:
  68. free_irq(irq, trig);
  69. error_free_trig_info:
  70. kfree(trig_info);
  71. error_put_trigger:
  72. iio_trigger_put(trig);
  73. error_ret:
  74. return ret;
  75. }
  76. static int iio_interrupt_trigger_remove(struct platform_device *pdev)
  77. {
  78. struct iio_trigger *trig;
  79. struct iio_interrupt_trigger_info *trig_info;
  80. trig = platform_get_drvdata(pdev);
  81. trig_info = iio_trigger_get_drvdata(trig);
  82. iio_trigger_unregister(trig);
  83. free_irq(trig_info->irq, trig);
  84. kfree(trig_info);
  85. iio_trigger_put(trig);
  86. return 0;
  87. }
  88. static struct platform_driver iio_interrupt_trigger_driver = {
  89. .probe = iio_interrupt_trigger_probe,
  90. .remove = iio_interrupt_trigger_remove,
  91. .driver = {
  92. .name = "iio_interrupt_trigger",
  93. .owner = THIS_MODULE,
  94. },
  95. };
  96. module_platform_driver(iio_interrupt_trigger_driver);
  97. MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
  98. MODULE_DESCRIPTION("Interrupt trigger for the iio subsystem");
  99. MODULE_LICENSE("GPL v2");