rtc-meson-vrtc.c 3.5 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Copyright (C) 2019 BayLibre, SAS
  4. * Author: Neil Armstrong <[email protected]>
  5. * Copyright (C) 2015 Amlogic, Inc. All rights reserved.
  6. */
  7. #include <linux/module.h>
  8. #include <linux/platform_device.h>
  9. #include <linux/rtc.h>
  10. #include <linux/io.h>
  11. #include <linux/of.h>
  12. #include <linux/time64.h>
  13. struct meson_vrtc_data {
  14. void __iomem *io_alarm;
  15. struct rtc_device *rtc;
  16. unsigned long alarm_time;
  17. bool enabled;
  18. };
  19. static int meson_vrtc_read_time(struct device *dev, struct rtc_time *tm)
  20. {
  21. struct timespec64 time;
  22. dev_dbg(dev, "%s\n", __func__);
  23. ktime_get_real_ts64(&time);
  24. rtc_time64_to_tm(time.tv_sec, tm);
  25. return 0;
  26. }
  27. static void meson_vrtc_set_wakeup_time(struct meson_vrtc_data *vrtc,
  28. unsigned long time)
  29. {
  30. writel_relaxed(time, vrtc->io_alarm);
  31. }
  32. static int meson_vrtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
  33. {
  34. struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
  35. dev_dbg(dev, "%s: alarm->enabled=%d\n", __func__, alarm->enabled);
  36. if (alarm->enabled)
  37. vrtc->alarm_time = rtc_tm_to_time64(&alarm->time);
  38. else
  39. vrtc->alarm_time = 0;
  40. return 0;
  41. }
  42. static int meson_vrtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  43. {
  44. struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
  45. vrtc->enabled = enabled;
  46. return 0;
  47. }
  48. static const struct rtc_class_ops meson_vrtc_ops = {
  49. .read_time = meson_vrtc_read_time,
  50. .set_alarm = meson_vrtc_set_alarm,
  51. .alarm_irq_enable = meson_vrtc_alarm_irq_enable,
  52. };
  53. static int meson_vrtc_probe(struct platform_device *pdev)
  54. {
  55. struct meson_vrtc_data *vrtc;
  56. vrtc = devm_kzalloc(&pdev->dev, sizeof(*vrtc), GFP_KERNEL);
  57. if (!vrtc)
  58. return -ENOMEM;
  59. vrtc->io_alarm = devm_platform_ioremap_resource(pdev, 0);
  60. if (IS_ERR(vrtc->io_alarm))
  61. return PTR_ERR(vrtc->io_alarm);
  62. device_init_wakeup(&pdev->dev, 1);
  63. platform_set_drvdata(pdev, vrtc);
  64. vrtc->rtc = devm_rtc_allocate_device(&pdev->dev);
  65. if (IS_ERR(vrtc->rtc))
  66. return PTR_ERR(vrtc->rtc);
  67. vrtc->rtc->ops = &meson_vrtc_ops;
  68. return devm_rtc_register_device(vrtc->rtc);
  69. }
  70. static int __maybe_unused meson_vrtc_suspend(struct device *dev)
  71. {
  72. struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
  73. dev_dbg(dev, "%s\n", __func__);
  74. if (vrtc->alarm_time) {
  75. unsigned long local_time;
  76. long alarm_secs;
  77. struct timespec64 time;
  78. ktime_get_real_ts64(&time);
  79. local_time = time.tv_sec;
  80. dev_dbg(dev, "alarm_time = %lus, local_time=%lus\n",
  81. vrtc->alarm_time, local_time);
  82. alarm_secs = vrtc->alarm_time - local_time;
  83. if (alarm_secs > 0) {
  84. meson_vrtc_set_wakeup_time(vrtc, alarm_secs);
  85. dev_dbg(dev, "system will wakeup in %lds.\n",
  86. alarm_secs);
  87. } else {
  88. dev_err(dev, "alarm time already passed: %lds.\n",
  89. alarm_secs);
  90. }
  91. }
  92. return 0;
  93. }
  94. static int __maybe_unused meson_vrtc_resume(struct device *dev)
  95. {
  96. struct meson_vrtc_data *vrtc = dev_get_drvdata(dev);
  97. dev_dbg(dev, "%s\n", __func__);
  98. vrtc->alarm_time = 0;
  99. meson_vrtc_set_wakeup_time(vrtc, 0);
  100. return 0;
  101. }
  102. static SIMPLE_DEV_PM_OPS(meson_vrtc_pm_ops,
  103. meson_vrtc_suspend, meson_vrtc_resume);
  104. static const struct of_device_id meson_vrtc_dt_match[] = {
  105. { .compatible = "amlogic,meson-vrtc"},
  106. {},
  107. };
  108. MODULE_DEVICE_TABLE(of, meson_vrtc_dt_match);
  109. static struct platform_driver meson_vrtc_driver = {
  110. .probe = meson_vrtc_probe,
  111. .driver = {
  112. .name = "meson-vrtc",
  113. .of_match_table = meson_vrtc_dt_match,
  114. .pm = &meson_vrtc_pm_ops,
  115. },
  116. };
  117. module_platform_driver(meson_vrtc_driver);
  118. MODULE_DESCRIPTION("Amlogic Virtual Wakeup RTC Timer driver");
  119. MODULE_LICENSE("GPL");