rtc-da9052.c 7.7 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Real time clock driver for DA9052
  4. *
  5. * Copyright(c) 2012 Dialog Semiconductor Ltd.
  6. *
  7. * Author: Dajun Dajun Chen <dajun.chen@diasemi.com>
  8. */
  9. #include <linux/module.h>
  10. #include <linux/platform_device.h>
  11. #include <linux/rtc.h>
  12. #include <linux/err.h>
  13. #include <linux/delay.h>
  14. #include <linux/mfd/da9052/da9052.h>
  15. #include <linux/mfd/da9052/reg.h>
  16. #define rtc_err(rtc, fmt, ...) \
  17. dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)
  18. #define DA9052_GET_TIME_RETRIES 5
  19. struct da9052_rtc {
  20. struct rtc_device *rtc;
  21. struct da9052 *da9052;
  22. };
  23. static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable)
  24. {
  25. int ret;
  26. if (enable) {
  27. ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
  28. DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON,
  29. DA9052_ALARM_Y_ALARM_ON);
  30. if (ret != 0)
  31. rtc_err(rtc, "Failed to enable ALM: %d\n", ret);
  32. } else {
  33. ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
  34. DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0);
  35. if (ret != 0)
  36. rtc_err(rtc, "Write error: %d\n", ret);
  37. }
  38. return ret;
  39. }
  40. static irqreturn_t da9052_rtc_irq(int irq, void *data)
  41. {
  42. struct da9052_rtc *rtc = data;
  43. rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
  44. return IRQ_HANDLED;
  45. }
  46. static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
  47. {
  48. int ret;
  49. uint8_t v[2][5];
  50. int idx = 1;
  51. int timeout = DA9052_GET_TIME_RETRIES;
  52. ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, &v[0][0]);
  53. if (ret) {
  54. rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
  55. return ret;
  56. }
  57. do {
  58. ret = da9052_group_read(rtc->da9052,
  59. DA9052_ALARM_MI_REG, 5, &v[idx][0]);
  60. if (ret) {
  61. rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
  62. return ret;
  63. }
  64. if (memcmp(&v[0][0], &v[1][0], 5) == 0) {
  65. rtc_tm->tm_year = (v[0][4] & DA9052_RTC_YEAR) + 100;
  66. rtc_tm->tm_mon = (v[0][3] & DA9052_RTC_MONTH) - 1;
  67. rtc_tm->tm_mday = v[0][2] & DA9052_RTC_DAY;
  68. rtc_tm->tm_hour = v[0][1] & DA9052_RTC_HOUR;
  69. rtc_tm->tm_min = v[0][0] & DA9052_RTC_MIN;
  70. rtc_tm->tm_sec = 0;
  71. ret = rtc_valid_tm(rtc_tm);
  72. return ret;
  73. }
  74. idx = (1-idx);
  75. msleep(20);
  76. } while (timeout--);
  77. rtc_err(rtc, "Timed out reading alarm time\n");
  78. return -EIO;
  79. }
  80. static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
  81. {
  82. struct da9052 *da9052 = rtc->da9052;
  83. unsigned long alm_time;
  84. int ret;
  85. uint8_t v[3];
  86. alm_time = rtc_tm_to_time64(rtc_tm);
  87. if (rtc_tm->tm_sec > 0) {
  88. alm_time += 60 - rtc_tm->tm_sec;
  89. rtc_time64_to_tm(alm_time, rtc_tm);
  90. }
  91. BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
  92. rtc_tm->tm_year -= 100;
  93. rtc_tm->tm_mon += 1;
  94. ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
  95. DA9052_RTC_MIN, rtc_tm->tm_min);
  96. if (ret != 0) {
  97. rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret);
  98. return ret;
  99. }
  100. v[0] = rtc_tm->tm_hour;
  101. v[1] = rtc_tm->tm_mday;
  102. v[2] = rtc_tm->tm_mon;
  103. ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
  104. if (ret < 0)
  105. return ret;
  106. ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
  107. DA9052_RTC_YEAR, rtc_tm->tm_year);
  108. if (ret != 0)
  109. rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret);
  110. return ret;
  111. }
  112. static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
  113. {
  114. int ret;
  115. ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
  116. if (ret < 0) {
  117. rtc_err(rtc, "Failed to read ALM: %d\n", ret);
  118. return ret;
  119. }
  120. return !!(ret&DA9052_ALARM_Y_ALARM_ON);
  121. }
  122. static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
  123. {
  124. struct da9052_rtc *rtc = dev_get_drvdata(dev);
  125. int ret;
  126. uint8_t v[2][6];
  127. int idx = 1;
  128. int timeout = DA9052_GET_TIME_RETRIES;
  129. ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]);
  130. if (ret) {
  131. rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
  132. return ret;
  133. }
  134. do {
  135. ret = da9052_group_read(rtc->da9052,
  136. DA9052_COUNT_S_REG, 6, &v[idx][0]);
  137. if (ret) {
  138. rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
  139. return ret;
  140. }
  141. if (memcmp(&v[0][0], &v[1][0], 6) == 0) {
  142. rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100;
  143. rtc_tm->tm_mon = (v[0][4] & DA9052_RTC_MONTH) - 1;
  144. rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY;
  145. rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR;
  146. rtc_tm->tm_min = v[0][1] & DA9052_RTC_MIN;
  147. rtc_tm->tm_sec = v[0][0] & DA9052_RTC_SEC;
  148. return 0;
  149. }
  150. idx = (1-idx);
  151. msleep(20);
  152. } while (timeout--);
  153. rtc_err(rtc, "Timed out reading time\n");
  154. return -EIO;
  155. }
  156. static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
  157. {
  158. struct da9052_rtc *rtc;
  159. uint8_t v[6];
  160. int ret;
  161. /* DA9052 only has 6 bits for year - to represent 2000-2063 */
  162. if ((tm->tm_year < 100) || (tm->tm_year > 163))
  163. return -EINVAL;
  164. rtc = dev_get_drvdata(dev);
  165. v[0] = tm->tm_sec;
  166. v[1] = tm->tm_min;
  167. v[2] = tm->tm_hour;
  168. v[3] = tm->tm_mday;
  169. v[4] = tm->tm_mon + 1;
  170. v[5] = tm->tm_year - 100;
  171. ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
  172. if (ret < 0)
  173. rtc_err(rtc, "failed to set RTC time: %d\n", ret);
  174. return ret;
  175. }
  176. static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  177. {
  178. int ret;
  179. struct rtc_time *tm = &alrm->time;
  180. struct da9052_rtc *rtc = dev_get_drvdata(dev);
  181. ret = da9052_read_alarm(rtc, tm);
  182. if (ret < 0) {
  183. rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
  184. return ret;
  185. }
  186. alrm->enabled = da9052_rtc_get_alarm_status(rtc);
  187. return 0;
  188. }
  189. static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  190. {
  191. int ret;
  192. struct rtc_time *tm = &alrm->time;
  193. struct da9052_rtc *rtc = dev_get_drvdata(dev);
  194. /* DA9052 only has 6 bits for year - to represent 2000-2063 */
  195. if ((tm->tm_year < 100) || (tm->tm_year > 163))
  196. return -EINVAL;
  197. ret = da9052_rtc_enable_alarm(rtc, 0);
  198. if (ret < 0)
  199. return ret;
  200. ret = da9052_set_alarm(rtc, tm);
  201. if (ret < 0)
  202. return ret;
  203. ret = da9052_rtc_enable_alarm(rtc, 1);
  204. return ret;
  205. }
  206. static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  207. {
  208. struct da9052_rtc *rtc = dev_get_drvdata(dev);
  209. return da9052_rtc_enable_alarm(rtc, enabled);
  210. }
  211. static const struct rtc_class_ops da9052_rtc_ops = {
  212. .read_time = da9052_rtc_read_time,
  213. .set_time = da9052_rtc_set_time,
  214. .read_alarm = da9052_rtc_read_alarm,
  215. .set_alarm = da9052_rtc_set_alarm,
  216. .alarm_irq_enable = da9052_rtc_alarm_irq_enable,
  217. };
  218. static int da9052_rtc_probe(struct platform_device *pdev)
  219. {
  220. struct da9052_rtc *rtc;
  221. int ret;
  222. rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
  223. if (!rtc)
  224. return -ENOMEM;
  225. rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
  226. platform_set_drvdata(pdev, rtc);
  227. ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
  228. if (ret < 0) {
  229. rtc_err(rtc,
  230. "Failed to setup RTC battery charging: %d\n", ret);
  231. return ret;
  232. }
  233. ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
  234. DA9052_ALARM_Y_TICK_ON, 0);
  235. if (ret != 0)
  236. rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
  237. device_init_wakeup(&pdev->dev, true);
  238. rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
  239. if (IS_ERR(rtc->rtc))
  240. return PTR_ERR(rtc->rtc);
  241. rtc->rtc->ops = &da9052_rtc_ops;
  242. rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
  243. rtc->rtc->range_max = RTC_TIMESTAMP_END_2063;
  244. ret = rtc_register_device(rtc->rtc);
  245. if (ret)
  246. return ret;
  247. ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
  248. da9052_rtc_irq, rtc);
  249. if (ret != 0) {
  250. rtc_err(rtc, "irq registration failed: %d\n", ret);
  251. return ret;
  252. }
  253. return 0;
  254. }
  255. static struct platform_driver da9052_rtc_driver = {
  256. .probe = da9052_rtc_probe,
  257. .driver = {
  258. .name = "da9052-rtc",
  259. },
  260. };
  261. module_platform_driver(da9052_rtc_driver);
  262. MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
  263. MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
  264. MODULE_LICENSE("GPL");
  265. MODULE_ALIAS("platform:da9052-rtc");