rtc-ep93xx.c 3.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * A driver for the RTC embedded in the Cirrus Logic EP93XX processors
  4. * Copyright (c) 2006 Tower Technologies
  5. *
  6. * Author: Alessandro Zummo <a.zummo@towertech.it>
  7. */
  8. #include <linux/module.h>
  9. #include <linux/rtc.h>
  10. #include <linux/platform_device.h>
  11. #include <linux/io.h>
  12. #include <linux/gfp.h>
  13. #define EP93XX_RTC_DATA 0x000
  14. #define EP93XX_RTC_MATCH 0x004
  15. #define EP93XX_RTC_STATUS 0x008
  16. #define EP93XX_RTC_STATUS_INTR BIT(0)
  17. #define EP93XX_RTC_LOAD 0x00C
  18. #define EP93XX_RTC_CONTROL 0x010
  19. #define EP93XX_RTC_CONTROL_MIE BIT(0)
  20. #define EP93XX_RTC_SWCOMP 0x108
  21. #define EP93XX_RTC_SWCOMP_DEL_MASK 0x001f0000
  22. #define EP93XX_RTC_SWCOMP_DEL_SHIFT 16
  23. #define EP93XX_RTC_SWCOMP_INT_MASK 0x0000ffff
  24. #define EP93XX_RTC_SWCOMP_INT_SHIFT 0
  25. struct ep93xx_rtc {
  26. void __iomem *mmio_base;
  27. struct rtc_device *rtc;
  28. };
  29. static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
  30. unsigned short *delete)
  31. {
  32. struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);
  33. unsigned long comp;
  34. comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
  35. if (preload)
  36. *preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
  37. >> EP93XX_RTC_SWCOMP_INT_SHIFT;
  38. if (delete)
  39. *delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
  40. >> EP93XX_RTC_SWCOMP_DEL_SHIFT;
  41. return 0;
  42. }
  43. static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
  44. {
  45. struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);
  46. unsigned long time;
  47. time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
  48. rtc_time64_to_tm(time, tm);
  49. return 0;
  50. }
  51. static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm)
  52. {
  53. struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);
  54. unsigned long secs = rtc_tm_to_time64(tm);
  55. writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
  56. return 0;
  57. }
  58. static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
  59. {
  60. unsigned short preload, delete;
  61. ep93xx_rtc_get_swcomp(dev, &preload, &delete);
  62. seq_printf(seq, "preload\t\t: %d\n", preload);
  63. seq_printf(seq, "delete\t\t: %d\n", delete);
  64. return 0;
  65. }
  66. static const struct rtc_class_ops ep93xx_rtc_ops = {
  67. .read_time = ep93xx_rtc_read_time,
  68. .set_time = ep93xx_rtc_set_time,
  69. .proc = ep93xx_rtc_proc,
  70. };
  71. static ssize_t comp_preload_show(struct device *dev,
  72. struct device_attribute *attr, char *buf)
  73. {
  74. unsigned short preload;
  75. ep93xx_rtc_get_swcomp(dev->parent, &preload, NULL);
  76. return sprintf(buf, "%d\n", preload);
  77. }
  78. static DEVICE_ATTR_RO(comp_preload);
  79. static ssize_t comp_delete_show(struct device *dev,
  80. struct device_attribute *attr, char *buf)
  81. {
  82. unsigned short delete;
  83. ep93xx_rtc_get_swcomp(dev->parent, NULL, &delete);
  84. return sprintf(buf, "%d\n", delete);
  85. }
  86. static DEVICE_ATTR_RO(comp_delete);
  87. static struct attribute *ep93xx_rtc_attrs[] = {
  88. &dev_attr_comp_preload.attr,
  89. &dev_attr_comp_delete.attr,
  90. NULL
  91. };
  92. static const struct attribute_group ep93xx_rtc_sysfs_files = {
  93. .attrs = ep93xx_rtc_attrs,
  94. };
  95. static int ep93xx_rtc_probe(struct platform_device *pdev)
  96. {
  97. struct ep93xx_rtc *ep93xx_rtc;
  98. int err;
  99. ep93xx_rtc = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_rtc), GFP_KERNEL);
  100. if (!ep93xx_rtc)
  101. return -ENOMEM;
  102. ep93xx_rtc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
  103. if (IS_ERR(ep93xx_rtc->mmio_base))
  104. return PTR_ERR(ep93xx_rtc->mmio_base);
  105. platform_set_drvdata(pdev, ep93xx_rtc);
  106. ep93xx_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
  107. if (IS_ERR(ep93xx_rtc->rtc))
  108. return PTR_ERR(ep93xx_rtc->rtc);
  109. ep93xx_rtc->rtc->ops = &ep93xx_rtc_ops;
  110. ep93xx_rtc->rtc->range_max = U32_MAX;
  111. err = rtc_add_group(ep93xx_rtc->rtc, &ep93xx_rtc_sysfs_files);
  112. if (err)
  113. return err;
  114. return rtc_register_device(ep93xx_rtc->rtc);
  115. }
  116. static struct platform_driver ep93xx_rtc_driver = {
  117. .driver = {
  118. .name = "ep93xx-rtc",
  119. },
  120. .probe = ep93xx_rtc_probe,
  121. };
  122. module_platform_driver(ep93xx_rtc_driver);
  123. MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
  124. MODULE_DESCRIPTION("EP93XX RTC driver");
  125. MODULE_LICENSE("GPL");
  126. MODULE_ALIAS("platform:ep93xx-rtc");