rtc-mv.c 8.5 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Driver for the RTC in Marvell SoCs.
  4. */
  5. #include <linux/init.h>
  6. #include <linux/kernel.h>
  7. #include <linux/rtc.h>
  8. #include <linux/bcd.h>
  9. #include <linux/bitops.h>
  10. #include <linux/io.h>
  11. #include <linux/platform_device.h>
  12. #include <linux/of.h>
  13. #include <linux/delay.h>
  14. #include <linux/clk.h>
  15. #include <linux/gfp.h>
  16. #include <linux/module.h>
  17. #define RTC_TIME_REG_OFFS 0
  18. #define RTC_SECONDS_OFFS 0
  19. #define RTC_MINUTES_OFFS 8
  20. #define RTC_HOURS_OFFS 16
  21. #define RTC_WDAY_OFFS 24
  22. #define RTC_HOURS_12H_MODE BIT(22) /* 12 hour mode */
  23. #define RTC_DATE_REG_OFFS 4
  24. #define RTC_MDAY_OFFS 0
  25. #define RTC_MONTH_OFFS 8
  26. #define RTC_YEAR_OFFS 16
  27. #define RTC_ALARM_TIME_REG_OFFS 8
  28. #define RTC_ALARM_DATE_REG_OFFS 0xc
  29. #define RTC_ALARM_VALID BIT(7)
  30. #define RTC_ALARM_INTERRUPT_MASK_REG_OFFS 0x10
  31. #define RTC_ALARM_INTERRUPT_CASUE_REG_OFFS 0x14
  32. struct rtc_plat_data {
  33. struct rtc_device *rtc;
  34. void __iomem *ioaddr;
  35. int irq;
  36. struct clk *clk;
  37. };
  38. static int mv_rtc_set_time(struct device *dev, struct rtc_time *tm)
  39. {
  40. struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  41. void __iomem *ioaddr = pdata->ioaddr;
  42. u32 rtc_reg;
  43. rtc_reg = (bin2bcd(tm->tm_sec) << RTC_SECONDS_OFFS) |
  44. (bin2bcd(tm->tm_min) << RTC_MINUTES_OFFS) |
  45. (bin2bcd(tm->tm_hour) << RTC_HOURS_OFFS) |
  46. (bin2bcd(tm->tm_wday) << RTC_WDAY_OFFS);
  47. writel(rtc_reg, ioaddr + RTC_TIME_REG_OFFS);
  48. rtc_reg = (bin2bcd(tm->tm_mday) << RTC_MDAY_OFFS) |
  49. (bin2bcd(tm->tm_mon + 1) << RTC_MONTH_OFFS) |
  50. (bin2bcd(tm->tm_year - 100) << RTC_YEAR_OFFS);
  51. writel(rtc_reg, ioaddr + RTC_DATE_REG_OFFS);
  52. return 0;
  53. }
  54. static int mv_rtc_read_time(struct device *dev, struct rtc_time *tm)
  55. {
  56. struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  57. void __iomem *ioaddr = pdata->ioaddr;
  58. u32 rtc_time, rtc_date;
  59. unsigned int year, month, day, hour, minute, second, wday;
  60. rtc_time = readl(ioaddr + RTC_TIME_REG_OFFS);
  61. rtc_date = readl(ioaddr + RTC_DATE_REG_OFFS);
  62. second = rtc_time & 0x7f;
  63. minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
  64. hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
  65. wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
  66. day = rtc_date & 0x3f;
  67. month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
  68. year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
  69. tm->tm_sec = bcd2bin(second);
  70. tm->tm_min = bcd2bin(minute);
  71. tm->tm_hour = bcd2bin(hour);
  72. tm->tm_mday = bcd2bin(day);
  73. tm->tm_wday = bcd2bin(wday);
  74. tm->tm_mon = bcd2bin(month) - 1;
  75. /* hw counts from year 2000, but tm_year is relative to 1900 */
  76. tm->tm_year = bcd2bin(year) + 100;
  77. return 0;
  78. }
  79. static int mv_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
  80. {
  81. struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  82. void __iomem *ioaddr = pdata->ioaddr;
  83. u32 rtc_time, rtc_date;
  84. unsigned int year, month, day, hour, minute, second, wday;
  85. rtc_time = readl(ioaddr + RTC_ALARM_TIME_REG_OFFS);
  86. rtc_date = readl(ioaddr + RTC_ALARM_DATE_REG_OFFS);
  87. second = rtc_time & 0x7f;
  88. minute = (rtc_time >> RTC_MINUTES_OFFS) & 0x7f;
  89. hour = (rtc_time >> RTC_HOURS_OFFS) & 0x3f; /* assume 24 hour mode */
  90. wday = (rtc_time >> RTC_WDAY_OFFS) & 0x7;
  91. day = rtc_date & 0x3f;
  92. month = (rtc_date >> RTC_MONTH_OFFS) & 0x3f;
  93. year = (rtc_date >> RTC_YEAR_OFFS) & 0xff;
  94. alm->time.tm_sec = bcd2bin(second);
  95. alm->time.tm_min = bcd2bin(minute);
  96. alm->time.tm_hour = bcd2bin(hour);
  97. alm->time.tm_mday = bcd2bin(day);
  98. alm->time.tm_wday = bcd2bin(wday);
  99. alm->time.tm_mon = bcd2bin(month) - 1;
  100. /* hw counts from year 2000, but tm_year is relative to 1900 */
  101. alm->time.tm_year = bcd2bin(year) + 100;
  102. alm->enabled = !!readl(ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
  103. return rtc_valid_tm(&alm->time);
  104. }
  105. static int mv_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
  106. {
  107. struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  108. void __iomem *ioaddr = pdata->ioaddr;
  109. u32 rtc_reg = 0;
  110. if (alm->time.tm_sec >= 0)
  111. rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_sec))
  112. << RTC_SECONDS_OFFS;
  113. if (alm->time.tm_min >= 0)
  114. rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_min))
  115. << RTC_MINUTES_OFFS;
  116. if (alm->time.tm_hour >= 0)
  117. rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_hour))
  118. << RTC_HOURS_OFFS;
  119. writel(rtc_reg, ioaddr + RTC_ALARM_TIME_REG_OFFS);
  120. if (alm->time.tm_mday >= 0)
  121. rtc_reg = (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mday))
  122. << RTC_MDAY_OFFS;
  123. else
  124. rtc_reg = 0;
  125. if (alm->time.tm_mon >= 0)
  126. rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_mon + 1))
  127. << RTC_MONTH_OFFS;
  128. if (alm->time.tm_year >= 0)
  129. rtc_reg |= (RTC_ALARM_VALID | bin2bcd(alm->time.tm_year - 100))
  130. << RTC_YEAR_OFFS;
  131. writel(rtc_reg, ioaddr + RTC_ALARM_DATE_REG_OFFS);
  132. writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
  133. writel(alm->enabled ? 1 : 0,
  134. ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
  135. return 0;
  136. }
  137. static int mv_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  138. {
  139. struct rtc_plat_data *pdata = dev_get_drvdata(dev);
  140. void __iomem *ioaddr = pdata->ioaddr;
  141. if (pdata->irq < 0)
  142. return -EINVAL; /* fall back into rtc-dev's emulation */
  143. if (enabled)
  144. writel(1, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
  145. else
  146. writel(0, ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
  147. return 0;
  148. }
  149. static irqreturn_t mv_rtc_interrupt(int irq, void *data)
  150. {
  151. struct rtc_plat_data *pdata = data;
  152. void __iomem *ioaddr = pdata->ioaddr;
  153. /* alarm irq? */
  154. if (!readl(ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS))
  155. return IRQ_NONE;
  156. /* clear interrupt */
  157. writel(0, ioaddr + RTC_ALARM_INTERRUPT_CASUE_REG_OFFS);
  158. rtc_update_irq(pdata->rtc, 1, RTC_IRQF | RTC_AF);
  159. return IRQ_HANDLED;
  160. }
  161. static const struct rtc_class_ops mv_rtc_ops = {
  162. .read_time = mv_rtc_read_time,
  163. .set_time = mv_rtc_set_time,
  164. };
  165. static const struct rtc_class_ops mv_rtc_alarm_ops = {
  166. .read_time = mv_rtc_read_time,
  167. .set_time = mv_rtc_set_time,
  168. .read_alarm = mv_rtc_read_alarm,
  169. .set_alarm = mv_rtc_set_alarm,
  170. .alarm_irq_enable = mv_rtc_alarm_irq_enable,
  171. };
  172. static int __init mv_rtc_probe(struct platform_device *pdev)
  173. {
  174. struct rtc_plat_data *pdata;
  175. u32 rtc_time;
  176. int ret = 0;
  177. pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
  178. if (!pdata)
  179. return -ENOMEM;
  180. pdata->ioaddr = devm_platform_ioremap_resource(pdev, 0);
  181. if (IS_ERR(pdata->ioaddr))
  182. return PTR_ERR(pdata->ioaddr);
  183. pdata->clk = devm_clk_get(&pdev->dev, NULL);
  184. /* Not all SoCs require a clock.*/
  185. if (!IS_ERR(pdata->clk))
  186. clk_prepare_enable(pdata->clk);
  187. /* make sure the 24 hour mode is enabled */
  188. rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
  189. if (rtc_time & RTC_HOURS_12H_MODE) {
  190. dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n");
  191. ret = -EINVAL;
  192. goto out;
  193. }
  194. /* make sure it is actually functional */
  195. if (rtc_time == 0x01000000) {
  196. ssleep(1);
  197. rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
  198. if (rtc_time == 0x01000000) {
  199. dev_err(&pdev->dev, "internal RTC not ticking\n");
  200. ret = -ENODEV;
  201. goto out;
  202. }
  203. }
  204. pdata->irq = platform_get_irq(pdev, 0);
  205. platform_set_drvdata(pdev, pdata);
  206. pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
  207. if (IS_ERR(pdata->rtc)) {
  208. ret = PTR_ERR(pdata->rtc);
  209. goto out;
  210. }
  211. if (pdata->irq >= 0) {
  212. writel(0, pdata->ioaddr + RTC_ALARM_INTERRUPT_MASK_REG_OFFS);
  213. if (devm_request_irq(&pdev->dev, pdata->irq, mv_rtc_interrupt,
  214. IRQF_SHARED,
  215. pdev->name, pdata) < 0) {
  216. dev_warn(&pdev->dev, "interrupt not available.\n");
  217. pdata->irq = -1;
  218. }
  219. }
  220. if (pdata->irq >= 0) {
  221. device_init_wakeup(&pdev->dev, 1);
  222. pdata->rtc->ops = &mv_rtc_alarm_ops;
  223. } else {
  224. pdata->rtc->ops = &mv_rtc_ops;
  225. }
  226. pdata->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
  227. pdata->rtc->range_max = RTC_TIMESTAMP_END_2099;
  228. ret = rtc_register_device(pdata->rtc);
  229. if (!ret)
  230. return 0;
  231. out:
  232. if (!IS_ERR(pdata->clk))
  233. clk_disable_unprepare(pdata->clk);
  234. return ret;
  235. }
  236. static int __exit mv_rtc_remove(struct platform_device *pdev)
  237. {
  238. struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
  239. if (pdata->irq >= 0)
  240. device_init_wakeup(&pdev->dev, 0);
  241. if (!IS_ERR(pdata->clk))
  242. clk_disable_unprepare(pdata->clk);
  243. return 0;
  244. }
  245. #ifdef CONFIG_OF
  246. static const struct of_device_id rtc_mv_of_match_table[] = {
  247. { .compatible = "marvell,orion-rtc", },
  248. {}
  249. };
  250. MODULE_DEVICE_TABLE(of, rtc_mv_of_match_table);
  251. #endif
  252. static struct platform_driver mv_rtc_driver = {
  253. .remove = __exit_p(mv_rtc_remove),
  254. .driver = {
  255. .name = "rtc-mv",
  256. .of_match_table = of_match_ptr(rtc_mv_of_match_table),
  257. },
  258. };
  259. module_platform_driver_probe(mv_rtc_driver, mv_rtc_probe);
  260. MODULE_AUTHOR("Saeed Bishara <saeed@marvell.com>");
  261. MODULE_DESCRIPTION("Marvell RTC driver");
  262. MODULE_LICENSE("GPL");
  263. MODULE_ALIAS("platform:rtc-mv");