rtc-da9055.c 9.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Real time clock driver for DA9055
  4. *
  5. * Copyright(c) 2012 Dialog Semiconductor Ltd.
  6. *
  7. * Author: Dajun Dajun Chen <[email protected]>
  8. */
  9. #include <linux/module.h>
  10. #include <linux/platform_device.h>
  11. #include <linux/rtc.h>
  12. #include <linux/mfd/da9055/core.h>
  13. #include <linux/mfd/da9055/reg.h>
  14. #include <linux/mfd/da9055/pdata.h>
  15. struct da9055_rtc {
  16. struct rtc_device *rtc;
  17. struct da9055 *da9055;
  18. int alarm_enable;
  19. };
  20. static int da9055_rtc_enable_alarm(struct da9055_rtc *rtc, bool enable)
  21. {
  22. int ret;
  23. if (enable) {
  24. ret = da9055_reg_update(rtc->da9055, DA9055_REG_ALARM_Y,
  25. DA9055_RTC_ALM_EN,
  26. DA9055_RTC_ALM_EN);
  27. if (ret != 0)
  28. dev_err(rtc->da9055->dev, "Failed to enable ALM: %d\n",
  29. ret);
  30. rtc->alarm_enable = 1;
  31. } else {
  32. ret = da9055_reg_update(rtc->da9055, DA9055_REG_ALARM_Y,
  33. DA9055_RTC_ALM_EN, 0);
  34. if (ret != 0)
  35. dev_err(rtc->da9055->dev,
  36. "Failed to disable ALM: %d\n", ret);
  37. rtc->alarm_enable = 0;
  38. }
  39. return ret;
  40. }
  41. static irqreturn_t da9055_rtc_alm_irq(int irq, void *data)
  42. {
  43. struct da9055_rtc *rtc = data;
  44. da9055_rtc_enable_alarm(rtc, 0);
  45. rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
  46. return IRQ_HANDLED;
  47. }
  48. static int da9055_read_alarm(struct da9055 *da9055, struct rtc_time *rtc_tm)
  49. {
  50. int ret;
  51. uint8_t v[5];
  52. ret = da9055_group_read(da9055, DA9055_REG_ALARM_MI, 5, v);
  53. if (ret != 0) {
  54. dev_err(da9055->dev, "Failed to group read ALM: %d\n", ret);
  55. return ret;
  56. }
  57. rtc_tm->tm_year = (v[4] & DA9055_RTC_ALM_YEAR) + 100;
  58. rtc_tm->tm_mon = (v[3] & DA9055_RTC_ALM_MONTH) - 1;
  59. rtc_tm->tm_mday = v[2] & DA9055_RTC_ALM_DAY;
  60. rtc_tm->tm_hour = v[1] & DA9055_RTC_ALM_HOUR;
  61. rtc_tm->tm_min = v[0] & DA9055_RTC_ALM_MIN;
  62. rtc_tm->tm_sec = 0;
  63. return rtc_valid_tm(rtc_tm);
  64. }
  65. static int da9055_set_alarm(struct da9055 *da9055, struct rtc_time *rtc_tm)
  66. {
  67. int ret;
  68. uint8_t v[2];
  69. rtc_tm->tm_year -= 100;
  70. rtc_tm->tm_mon += 1;
  71. ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MI,
  72. DA9055_RTC_ALM_MIN, rtc_tm->tm_min);
  73. if (ret != 0) {
  74. dev_err(da9055->dev, "Failed to write ALRM MIN: %d\n", ret);
  75. return ret;
  76. }
  77. v[0] = rtc_tm->tm_hour;
  78. v[1] = rtc_tm->tm_mday;
  79. ret = da9055_group_write(da9055, DA9055_REG_ALARM_H, 2, v);
  80. if (ret < 0)
  81. return ret;
  82. ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
  83. DA9055_RTC_ALM_MONTH, rtc_tm->tm_mon);
  84. if (ret < 0)
  85. dev_err(da9055->dev, "Failed to write ALM Month:%d\n", ret);
  86. ret = da9055_reg_update(da9055, DA9055_REG_ALARM_Y,
  87. DA9055_RTC_ALM_YEAR, rtc_tm->tm_year);
  88. if (ret < 0)
  89. dev_err(da9055->dev, "Failed to write ALM Year:%d\n", ret);
  90. return ret;
  91. }
  92. static int da9055_rtc_get_alarm_status(struct da9055 *da9055)
  93. {
  94. int ret;
  95. ret = da9055_reg_read(da9055, DA9055_REG_ALARM_Y);
  96. if (ret < 0) {
  97. dev_err(da9055->dev, "Failed to read ALM: %d\n", ret);
  98. return ret;
  99. }
  100. ret &= DA9055_RTC_ALM_EN;
  101. return (ret > 0) ? 1 : 0;
  102. }
  103. static int da9055_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
  104. {
  105. struct da9055_rtc *rtc = dev_get_drvdata(dev);
  106. uint8_t v[6];
  107. int ret;
  108. ret = da9055_reg_read(rtc->da9055, DA9055_REG_COUNT_S);
  109. if (ret < 0)
  110. return ret;
  111. /*
  112. * Registers are only valid when RTC_READ
  113. * status bit is asserted
  114. */
  115. if (!(ret & DA9055_RTC_READ))
  116. return -EBUSY;
  117. ret = da9055_group_read(rtc->da9055, DA9055_REG_COUNT_S, 6, v);
  118. if (ret < 0) {
  119. dev_err(rtc->da9055->dev, "Failed to read RTC time : %d\n",
  120. ret);
  121. return ret;
  122. }
  123. rtc_tm->tm_year = (v[5] & DA9055_RTC_YEAR) + 100;
  124. rtc_tm->tm_mon = (v[4] & DA9055_RTC_MONTH) - 1;
  125. rtc_tm->tm_mday = v[3] & DA9055_RTC_DAY;
  126. rtc_tm->tm_hour = v[2] & DA9055_RTC_HOUR;
  127. rtc_tm->tm_min = v[1] & DA9055_RTC_MIN;
  128. rtc_tm->tm_sec = v[0] & DA9055_RTC_SEC;
  129. return 0;
  130. }
  131. static int da9055_rtc_set_time(struct device *dev, struct rtc_time *tm)
  132. {
  133. struct da9055_rtc *rtc;
  134. uint8_t v[6];
  135. rtc = dev_get_drvdata(dev);
  136. v[0] = tm->tm_sec;
  137. v[1] = tm->tm_min;
  138. v[2] = tm->tm_hour;
  139. v[3] = tm->tm_mday;
  140. v[4] = tm->tm_mon + 1;
  141. v[5] = tm->tm_year - 100;
  142. return da9055_group_write(rtc->da9055, DA9055_REG_COUNT_S, 6, v);
  143. }
  144. static int da9055_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  145. {
  146. int ret;
  147. struct rtc_time *tm = &alrm->time;
  148. struct da9055_rtc *rtc = dev_get_drvdata(dev);
  149. ret = da9055_read_alarm(rtc->da9055, tm);
  150. if (ret)
  151. return ret;
  152. alrm->enabled = da9055_rtc_get_alarm_status(rtc->da9055);
  153. return 0;
  154. }
  155. static int da9055_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  156. {
  157. int ret;
  158. struct rtc_time *tm = &alrm->time;
  159. struct da9055_rtc *rtc = dev_get_drvdata(dev);
  160. ret = da9055_rtc_enable_alarm(rtc, 0);
  161. if (ret < 0)
  162. return ret;
  163. ret = da9055_set_alarm(rtc->da9055, tm);
  164. if (ret)
  165. return ret;
  166. ret = da9055_rtc_enable_alarm(rtc, 1);
  167. return ret;
  168. }
  169. static int da9055_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  170. {
  171. struct da9055_rtc *rtc = dev_get_drvdata(dev);
  172. return da9055_rtc_enable_alarm(rtc, enabled);
  173. }
  174. static const struct rtc_class_ops da9055_rtc_ops = {
  175. .read_time = da9055_rtc_read_time,
  176. .set_time = da9055_rtc_set_time,
  177. .read_alarm = da9055_rtc_read_alarm,
  178. .set_alarm = da9055_rtc_set_alarm,
  179. .alarm_irq_enable = da9055_rtc_alarm_irq_enable,
  180. };
  181. static int da9055_rtc_device_init(struct da9055 *da9055,
  182. struct da9055_pdata *pdata)
  183. {
  184. int ret;
  185. /* Enable RTC and the internal Crystal */
  186. ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
  187. DA9055_RTC_EN, DA9055_RTC_EN);
  188. if (ret < 0)
  189. return ret;
  190. ret = da9055_reg_update(da9055, DA9055_REG_EN_32K,
  191. DA9055_CRYSTAL_EN, DA9055_CRYSTAL_EN);
  192. if (ret < 0)
  193. return ret;
  194. /* Enable RTC in Power Down mode */
  195. ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
  196. DA9055_RTC_MODE_PD, DA9055_RTC_MODE_PD);
  197. if (ret < 0)
  198. return ret;
  199. /* Enable RTC in Reset mode */
  200. if (pdata && pdata->reset_enable) {
  201. ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
  202. DA9055_RTC_MODE_SD,
  203. DA9055_RTC_MODE_SD <<
  204. DA9055_RTC_MODE_SD_SHIFT);
  205. if (ret < 0)
  206. return ret;
  207. }
  208. /* Disable the RTC TICK ALM */
  209. ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
  210. DA9055_RTC_TICK_WAKE_MASK, 0);
  211. if (ret < 0)
  212. return ret;
  213. return 0;
  214. }
  215. static int da9055_rtc_probe(struct platform_device *pdev)
  216. {
  217. struct da9055_rtc *rtc;
  218. struct da9055_pdata *pdata = NULL;
  219. int ret, alm_irq;
  220. rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9055_rtc), GFP_KERNEL);
  221. if (!rtc)
  222. return -ENOMEM;
  223. rtc->da9055 = dev_get_drvdata(pdev->dev.parent);
  224. pdata = dev_get_platdata(rtc->da9055->dev);
  225. platform_set_drvdata(pdev, rtc);
  226. ret = da9055_rtc_device_init(rtc->da9055, pdata);
  227. if (ret < 0)
  228. goto err_rtc;
  229. ret = da9055_reg_read(rtc->da9055, DA9055_REG_ALARM_Y);
  230. if (ret < 0)
  231. goto err_rtc;
  232. if (ret & DA9055_RTC_ALM_EN)
  233. rtc->alarm_enable = 1;
  234. device_init_wakeup(&pdev->dev, 1);
  235. rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
  236. &da9055_rtc_ops, THIS_MODULE);
  237. if (IS_ERR(rtc->rtc)) {
  238. ret = PTR_ERR(rtc->rtc);
  239. goto err_rtc;
  240. }
  241. alm_irq = platform_get_irq_byname(pdev, "ALM");
  242. if (alm_irq < 0)
  243. return alm_irq;
  244. ret = devm_request_threaded_irq(&pdev->dev, alm_irq, NULL,
  245. da9055_rtc_alm_irq,
  246. IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
  247. "ALM", rtc);
  248. if (ret != 0)
  249. dev_err(rtc->da9055->dev, "irq registration failed: %d\n", ret);
  250. err_rtc:
  251. return ret;
  252. }
  253. #ifdef CONFIG_PM
  254. /* Turn off the alarm if it should not be a wake source. */
  255. static int da9055_rtc_suspend(struct device *dev)
  256. {
  257. struct platform_device *pdev = to_platform_device(dev);
  258. struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
  259. int ret;
  260. if (!device_may_wakeup(&pdev->dev)) {
  261. /* Disable the ALM IRQ */
  262. ret = da9055_rtc_enable_alarm(rtc, 0);
  263. if (ret < 0)
  264. dev_err(&pdev->dev, "Failed to disable RTC ALM\n");
  265. }
  266. return 0;
  267. }
  268. /* Enable the alarm if it should be enabled (in case it was disabled to
  269. * prevent use as a wake source).
  270. */
  271. static int da9055_rtc_resume(struct device *dev)
  272. {
  273. struct platform_device *pdev = to_platform_device(dev);
  274. struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
  275. int ret;
  276. if (!device_may_wakeup(&pdev->dev)) {
  277. if (rtc->alarm_enable) {
  278. ret = da9055_rtc_enable_alarm(rtc, 1);
  279. if (ret < 0)
  280. dev_err(&pdev->dev,
  281. "Failed to restart RTC ALM\n");
  282. }
  283. }
  284. return 0;
  285. }
  286. /* Unconditionally disable the alarm */
  287. static int da9055_rtc_freeze(struct device *dev)
  288. {
  289. struct platform_device *pdev = to_platform_device(dev);
  290. struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
  291. int ret;
  292. ret = da9055_rtc_enable_alarm(rtc, 0);
  293. if (ret < 0)
  294. dev_err(&pdev->dev, "Failed to freeze RTC ALMs\n");
  295. return 0;
  296. }
  297. #else
  298. #define da9055_rtc_suspend NULL
  299. #define da9055_rtc_resume NULL
  300. #define da9055_rtc_freeze NULL
  301. #endif
  302. static const struct dev_pm_ops da9055_rtc_pm_ops = {
  303. .suspend = da9055_rtc_suspend,
  304. .resume = da9055_rtc_resume,
  305. .freeze = da9055_rtc_freeze,
  306. .thaw = da9055_rtc_resume,
  307. .restore = da9055_rtc_resume,
  308. .poweroff = da9055_rtc_suspend,
  309. };
  310. static struct platform_driver da9055_rtc_driver = {
  311. .probe = da9055_rtc_probe,
  312. .driver = {
  313. .name = "da9055-rtc",
  314. .pm = &da9055_rtc_pm_ops,
  315. },
  316. };
  317. module_platform_driver(da9055_rtc_driver);
  318. MODULE_AUTHOR("David Dajun Chen <[email protected]>");
  319. MODULE_DESCRIPTION("RTC driver for Dialog DA9055 PMIC");
  320. MODULE_LICENSE("GPL");
  321. MODULE_ALIAS("platform:da9055-rtc");