rtc-max8925.c 8.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * RTC driver for Maxim MAX8925
  4. *
  5. * Copyright (C) 2009-2010 Marvell International Ltd.
  6. * Haojian Zhuang <haojian.zhuang@marvell.com>
  7. */
  8. #include <linux/module.h>
  9. #include <linux/i2c.h>
  10. #include <linux/slab.h>
  11. #include <linux/rtc.h>
  12. #include <linux/platform_device.h>
  13. #include <linux/mfd/max8925.h>
  14. enum {
  15. RTC_SEC = 0,
  16. RTC_MIN,
  17. RTC_HOUR,
  18. RTC_WEEKDAY,
  19. RTC_DATE,
  20. RTC_MONTH,
  21. RTC_YEAR1,
  22. RTC_YEAR2,
  23. };
  24. #define MAX8925_RTC_SEC 0x00
  25. #define MAX8925_RTC_MIN 0x01
  26. #define MAX8925_RTC_HOUR 0x02
  27. #define MAX8925_RTC_WEEKDAY 0x03
  28. #define MAX8925_RTC_DATE 0x04
  29. #define MAX8925_RTC_MONTH 0x05
  30. #define MAX8925_RTC_YEAR1 0x06
  31. #define MAX8925_RTC_YEAR2 0x07
  32. #define MAX8925_ALARM0_SEC 0x08
  33. #define MAX8925_ALARM0_MIN 0x09
  34. #define MAX8925_ALARM0_HOUR 0x0a
  35. #define MAX8925_ALARM0_WEEKDAY 0x0b
  36. #define MAX8925_ALARM0_DATE 0x0c
  37. #define MAX8925_ALARM0_MON 0x0d
  38. #define MAX8925_ALARM0_YEAR1 0x0e
  39. #define MAX8925_ALARM0_YEAR2 0x0f
  40. #define MAX8925_ALARM1_SEC 0x10
  41. #define MAX8925_ALARM1_MIN 0x11
  42. #define MAX8925_ALARM1_HOUR 0x12
  43. #define MAX8925_ALARM1_WEEKDAY 0x13
  44. #define MAX8925_ALARM1_DATE 0x14
  45. #define MAX8925_ALARM1_MON 0x15
  46. #define MAX8925_ALARM1_YEAR1 0x16
  47. #define MAX8925_ALARM1_YEAR2 0x17
  48. #define MAX8925_RTC_CNTL 0x1b
  49. #define MAX8925_RTC_STATUS 0x20
  50. #define TIME_NUM 8
  51. #define ALARM_1SEC (1 << 7)
  52. #define HOUR_12 (1 << 7)
  53. #define HOUR_AM_PM (1 << 5)
  54. #define ALARM0_IRQ (1 << 3)
  55. #define ALARM1_IRQ (1 << 2)
  56. #define ALARM0_STATUS (1 << 2)
  57. #define ALARM1_STATUS (1 << 1)
  58. struct max8925_rtc_info {
  59. struct rtc_device *rtc_dev;
  60. struct max8925_chip *chip;
  61. struct i2c_client *rtc;
  62. struct device *dev;
  63. int irq;
  64. };
  65. static irqreturn_t rtc_update_handler(int irq, void *data)
  66. {
  67. struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
  68. /* disable ALARM0 except for 1SEC alarm */
  69. max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
  70. rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
  71. return IRQ_HANDLED;
  72. }
  73. static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
  74. {
  75. if (len < TIME_NUM)
  76. return -EINVAL;
  77. tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
  78. + (buf[RTC_YEAR2] & 0xf) * 100
  79. + (buf[RTC_YEAR1] >> 4) * 10
  80. + (buf[RTC_YEAR1] & 0xf);
  81. tm->tm_year -= 1900;
  82. tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
  83. + (buf[RTC_MONTH] & 0x0f);
  84. tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
  85. + (buf[RTC_DATE] & 0x0f);
  86. tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
  87. if (buf[RTC_HOUR] & HOUR_12) {
  88. tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
  89. + (buf[RTC_HOUR] & 0x0f);
  90. if (buf[RTC_HOUR] & HOUR_AM_PM)
  91. tm->tm_hour += 12;
  92. } else
  93. tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
  94. + (buf[RTC_HOUR] & 0x0f);
  95. tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
  96. + (buf[RTC_MIN] & 0x0f);
  97. tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
  98. + (buf[RTC_SEC] & 0x0f);
  99. return 0;
  100. }
  101. static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
  102. {
  103. unsigned char high, low;
  104. if (len < TIME_NUM)
  105. return -EINVAL;
  106. high = (tm->tm_year + 1900) / 1000;
  107. low = (tm->tm_year + 1900) / 100;
  108. low = low - high * 10;
  109. buf[RTC_YEAR2] = (high << 4) + low;
  110. high = (tm->tm_year + 1900) / 10;
  111. low = tm->tm_year + 1900;
  112. low = low - high * 10;
  113. high = high - (high / 10) * 10;
  114. buf[RTC_YEAR1] = (high << 4) + low;
  115. high = tm->tm_mon / 10;
  116. low = tm->tm_mon;
  117. low = low - high * 10;
  118. buf[RTC_MONTH] = (high << 4) + low;
  119. high = tm->tm_mday / 10;
  120. low = tm->tm_mday;
  121. low = low - high * 10;
  122. buf[RTC_DATE] = (high << 4) + low;
  123. buf[RTC_WEEKDAY] = tm->tm_wday;
  124. high = tm->tm_hour / 10;
  125. low = tm->tm_hour;
  126. low = low - high * 10;
  127. buf[RTC_HOUR] = (high << 4) + low;
  128. high = tm->tm_min / 10;
  129. low = tm->tm_min;
  130. low = low - high * 10;
  131. buf[RTC_MIN] = (high << 4) + low;
  132. high = tm->tm_sec / 10;
  133. low = tm->tm_sec;
  134. low = low - high * 10;
  135. buf[RTC_SEC] = (high << 4) + low;
  136. return 0;
  137. }
  138. static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
  139. {
  140. struct max8925_rtc_info *info = dev_get_drvdata(dev);
  141. unsigned char buf[TIME_NUM];
  142. int ret;
  143. ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
  144. if (ret < 0)
  145. goto out;
  146. ret = tm_calc(tm, buf, TIME_NUM);
  147. out:
  148. return ret;
  149. }
  150. static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
  151. {
  152. struct max8925_rtc_info *info = dev_get_drvdata(dev);
  153. unsigned char buf[TIME_NUM];
  154. int ret;
  155. ret = data_calc(buf, tm, TIME_NUM);
  156. if (ret < 0)
  157. goto out;
  158. ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
  159. out:
  160. return ret;
  161. }
  162. static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  163. {
  164. struct max8925_rtc_info *info = dev_get_drvdata(dev);
  165. unsigned char buf[TIME_NUM];
  166. int ret;
  167. ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
  168. if (ret < 0)
  169. goto out;
  170. ret = tm_calc(&alrm->time, buf, TIME_NUM);
  171. if (ret < 0)
  172. goto out;
  173. ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
  174. if (ret < 0)
  175. goto out;
  176. if (ret & ALARM0_IRQ) {
  177. alrm->enabled = 0;
  178. } else {
  179. ret = max8925_reg_read(info->rtc, MAX8925_ALARM0_CNTL);
  180. if (ret < 0)
  181. goto out;
  182. if (!ret)
  183. alrm->enabled = 0;
  184. else
  185. alrm->enabled = 1;
  186. }
  187. ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
  188. if (ret < 0)
  189. goto out;
  190. if (ret & ALARM0_STATUS)
  191. alrm->pending = 1;
  192. else
  193. alrm->pending = 0;
  194. return 0;
  195. out:
  196. return ret;
  197. }
  198. static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  199. {
  200. struct max8925_rtc_info *info = dev_get_drvdata(dev);
  201. unsigned char buf[TIME_NUM];
  202. int ret;
  203. ret = data_calc(buf, &alrm->time, TIME_NUM);
  204. if (ret < 0)
  205. goto out;
  206. ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
  207. if (ret < 0)
  208. goto out;
  209. if (alrm->enabled)
  210. /* only enable alarm on year/month/day/hour/min/sec */
  211. ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
  212. else
  213. ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x0);
  214. out:
  215. return ret;
  216. }
  217. static const struct rtc_class_ops max8925_rtc_ops = {
  218. .read_time = max8925_rtc_read_time,
  219. .set_time = max8925_rtc_set_time,
  220. .read_alarm = max8925_rtc_read_alarm,
  221. .set_alarm = max8925_rtc_set_alarm,
  222. };
  223. static int max8925_rtc_probe(struct platform_device *pdev)
  224. {
  225. struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
  226. struct max8925_rtc_info *info;
  227. int ret;
  228. info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_rtc_info),
  229. GFP_KERNEL);
  230. if (!info)
  231. return -ENOMEM;
  232. info->chip = chip;
  233. info->rtc = chip->rtc;
  234. info->dev = &pdev->dev;
  235. info->irq = platform_get_irq(pdev, 0);
  236. ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
  237. rtc_update_handler, IRQF_ONESHOT,
  238. "rtc-alarm0", info);
  239. if (ret < 0) {
  240. dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
  241. info->irq, ret);
  242. return ret;
  243. }
  244. dev_set_drvdata(&pdev->dev, info);
  245. /* XXX - isn't this redundant? */
  246. platform_set_drvdata(pdev, info);
  247. device_init_wakeup(&pdev->dev, 1);
  248. info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8925-rtc",
  249. &max8925_rtc_ops, THIS_MODULE);
  250. ret = PTR_ERR(info->rtc_dev);
  251. if (IS_ERR(info->rtc_dev)) {
  252. dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
  253. return ret;
  254. }
  255. return 0;
  256. }
  257. #ifdef CONFIG_PM_SLEEP
  258. static int max8925_rtc_suspend(struct device *dev)
  259. {
  260. struct platform_device *pdev = to_platform_device(dev);
  261. struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
  262. if (device_may_wakeup(dev))
  263. chip->wakeup_flag |= 1 << MAX8925_IRQ_RTC_ALARM0;
  264. return 0;
  265. }
  266. static int max8925_rtc_resume(struct device *dev)
  267. {
  268. struct platform_device *pdev = to_platform_device(dev);
  269. struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
  270. if (device_may_wakeup(dev))
  271. chip->wakeup_flag &= ~(1 << MAX8925_IRQ_RTC_ALARM0);
  272. return 0;
  273. }
  274. #endif
  275. static SIMPLE_DEV_PM_OPS(max8925_rtc_pm_ops, max8925_rtc_suspend, max8925_rtc_resume);
  276. static struct platform_driver max8925_rtc_driver = {
  277. .driver = {
  278. .name = "max8925-rtc",
  279. .pm = &max8925_rtc_pm_ops,
  280. },
  281. .probe = max8925_rtc_probe,
  282. };
  283. module_platform_driver(max8925_rtc_driver);
  284. MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
  285. MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
  286. MODULE_LICENSE("GPL");