rtc-sc27xx.c 17 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647
  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * Copyright (C) 2017 Spreadtrum Communications Inc.
  4. *
  5. */
  6. #include <linux/bitops.h>
  7. #include <linux/delay.h>
  8. #include <linux/err.h>
  9. #include <linux/module.h>
  10. #include <linux/of.h>
  11. #include <linux/platform_device.h>
  12. #include <linux/regmap.h>
  13. #include <linux/rtc.h>
  14. #define SPRD_RTC_SEC_CNT_VALUE 0x0
  15. #define SPRD_RTC_MIN_CNT_VALUE 0x4
  16. #define SPRD_RTC_HOUR_CNT_VALUE 0x8
  17. #define SPRD_RTC_DAY_CNT_VALUE 0xc
  18. #define SPRD_RTC_SEC_CNT_UPD 0x10
  19. #define SPRD_RTC_MIN_CNT_UPD 0x14
  20. #define SPRD_RTC_HOUR_CNT_UPD 0x18
  21. #define SPRD_RTC_DAY_CNT_UPD 0x1c
  22. #define SPRD_RTC_SEC_ALM_UPD 0x20
  23. #define SPRD_RTC_MIN_ALM_UPD 0x24
  24. #define SPRD_RTC_HOUR_ALM_UPD 0x28
  25. #define SPRD_RTC_DAY_ALM_UPD 0x2c
  26. #define SPRD_RTC_INT_EN 0x30
  27. #define SPRD_RTC_INT_RAW_STS 0x34
  28. #define SPRD_RTC_INT_CLR 0x38
  29. #define SPRD_RTC_INT_MASK_STS 0x3C
  30. #define SPRD_RTC_SEC_ALM_VALUE 0x40
  31. #define SPRD_RTC_MIN_ALM_VALUE 0x44
  32. #define SPRD_RTC_HOUR_ALM_VALUE 0x48
  33. #define SPRD_RTC_DAY_ALM_VALUE 0x4c
  34. #define SPRD_RTC_SPG_VALUE 0x50
  35. #define SPRD_RTC_SPG_UPD 0x54
  36. #define SPRD_RTC_PWR_CTRL 0x58
  37. #define SPRD_RTC_PWR_STS 0x5c
  38. #define SPRD_RTC_SEC_AUXALM_UPD 0x60
  39. #define SPRD_RTC_MIN_AUXALM_UPD 0x64
  40. #define SPRD_RTC_HOUR_AUXALM_UPD 0x68
  41. #define SPRD_RTC_DAY_AUXALM_UPD 0x6c
  42. /* BIT & MASK definition for SPRD_RTC_INT_* registers */
  43. #define SPRD_RTC_SEC_EN BIT(0)
  44. #define SPRD_RTC_MIN_EN BIT(1)
  45. #define SPRD_RTC_HOUR_EN BIT(2)
  46. #define SPRD_RTC_DAY_EN BIT(3)
  47. #define SPRD_RTC_ALARM_EN BIT(4)
  48. #define SPRD_RTC_HRS_FORMAT_EN BIT(5)
  49. #define SPRD_RTC_AUXALM_EN BIT(6)
  50. #define SPRD_RTC_SPG_UPD_EN BIT(7)
  51. #define SPRD_RTC_SEC_UPD_EN BIT(8)
  52. #define SPRD_RTC_MIN_UPD_EN BIT(9)
  53. #define SPRD_RTC_HOUR_UPD_EN BIT(10)
  54. #define SPRD_RTC_DAY_UPD_EN BIT(11)
  55. #define SPRD_RTC_ALMSEC_UPD_EN BIT(12)
  56. #define SPRD_RTC_ALMMIN_UPD_EN BIT(13)
  57. #define SPRD_RTC_ALMHOUR_UPD_EN BIT(14)
  58. #define SPRD_RTC_ALMDAY_UPD_EN BIT(15)
  59. #define SPRD_RTC_INT_MASK GENMASK(15, 0)
  60. #define SPRD_RTC_TIME_INT_MASK \
  61. (SPRD_RTC_SEC_UPD_EN | SPRD_RTC_MIN_UPD_EN | \
  62. SPRD_RTC_HOUR_UPD_EN | SPRD_RTC_DAY_UPD_EN)
  63. #define SPRD_RTC_ALMTIME_INT_MASK \
  64. (SPRD_RTC_ALMSEC_UPD_EN | SPRD_RTC_ALMMIN_UPD_EN | \
  65. SPRD_RTC_ALMHOUR_UPD_EN | SPRD_RTC_ALMDAY_UPD_EN)
  66. #define SPRD_RTC_ALM_INT_MASK \
  67. (SPRD_RTC_SEC_EN | SPRD_RTC_MIN_EN | \
  68. SPRD_RTC_HOUR_EN | SPRD_RTC_DAY_EN | \
  69. SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN)
  70. /* second/minute/hour/day values mask definition */
  71. #define SPRD_RTC_SEC_MASK GENMASK(5, 0)
  72. #define SPRD_RTC_MIN_MASK GENMASK(5, 0)
  73. #define SPRD_RTC_HOUR_MASK GENMASK(4, 0)
  74. #define SPRD_RTC_DAY_MASK GENMASK(15, 0)
  75. /* alarm lock definition for SPRD_RTC_SPG_UPD register */
  76. #define SPRD_RTC_ALMLOCK_MASK GENMASK(7, 0)
  77. #define SPRD_RTC_ALM_UNLOCK 0xa5
  78. #define SPRD_RTC_ALM_LOCK (~SPRD_RTC_ALM_UNLOCK & \
  79. SPRD_RTC_ALMLOCK_MASK)
  80. /* SPG values definition for SPRD_RTC_SPG_UPD register */
  81. #define SPRD_RTC_POWEROFF_ALM_FLAG BIT(8)
  82. /* power control/status definition */
  83. #define SPRD_RTC_POWER_RESET_VALUE 0x96
  84. #define SPRD_RTC_POWER_STS_CLEAR GENMASK(7, 0)
  85. #define SPRD_RTC_POWER_STS_SHIFT 8
  86. #define SPRD_RTC_POWER_STS_VALID \
  87. (~SPRD_RTC_POWER_RESET_VALUE << SPRD_RTC_POWER_STS_SHIFT)
  88. /* timeout of synchronizing time and alarm registers (us) */
  89. #define SPRD_RTC_POLL_TIMEOUT 200000
  90. #define SPRD_RTC_POLL_DELAY_US 20000
  91. struct sprd_rtc {
  92. struct rtc_device *rtc;
  93. struct regmap *regmap;
  94. struct device *dev;
  95. u32 base;
  96. int irq;
  97. bool valid;
  98. };
  99. /*
  100. * The Spreadtrum RTC controller has 3 groups registers, including time, normal
  101. * alarm and auxiliary alarm. The time group registers are used to set RTC time,
  102. * the normal alarm registers are used to set normal alarm, and the auxiliary
  103. * alarm registers are used to set auxiliary alarm. Both alarm event and
  104. * auxiliary alarm event can wake up system from deep sleep, but only alarm
  105. * event can power up system from power down status.
  106. */
  107. enum sprd_rtc_reg_types {
  108. SPRD_RTC_TIME,
  109. SPRD_RTC_ALARM,
  110. SPRD_RTC_AUX_ALARM,
  111. };
  112. static int sprd_rtc_clear_alarm_ints(struct sprd_rtc *rtc)
  113. {
  114. return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
  115. SPRD_RTC_ALM_INT_MASK);
  116. }
  117. static int sprd_rtc_lock_alarm(struct sprd_rtc *rtc, bool lock)
  118. {
  119. int ret;
  120. u32 val;
  121. ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
  122. if (ret)
  123. return ret;
  124. val &= ~SPRD_RTC_ALMLOCK_MASK;
  125. if (lock)
  126. val |= SPRD_RTC_ALM_LOCK;
  127. else
  128. val |= SPRD_RTC_ALM_UNLOCK | SPRD_RTC_POWEROFF_ALM_FLAG;
  129. ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_SPG_UPD, val);
  130. if (ret)
  131. return ret;
  132. /* wait until the SPG value is updated successfully */
  133. ret = regmap_read_poll_timeout(rtc->regmap,
  134. rtc->base + SPRD_RTC_INT_RAW_STS, val,
  135. (val & SPRD_RTC_SPG_UPD_EN),
  136. SPRD_RTC_POLL_DELAY_US,
  137. SPRD_RTC_POLL_TIMEOUT);
  138. if (ret) {
  139. dev_err(rtc->dev, "failed to update SPG value:%d\n", ret);
  140. return ret;
  141. }
  142. return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
  143. SPRD_RTC_SPG_UPD_EN);
  144. }
  145. static int sprd_rtc_get_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
  146. time64_t *secs)
  147. {
  148. u32 sec_reg, min_reg, hour_reg, day_reg;
  149. u32 val, sec, min, hour, day;
  150. int ret;
  151. switch (type) {
  152. case SPRD_RTC_TIME:
  153. sec_reg = SPRD_RTC_SEC_CNT_VALUE;
  154. min_reg = SPRD_RTC_MIN_CNT_VALUE;
  155. hour_reg = SPRD_RTC_HOUR_CNT_VALUE;
  156. day_reg = SPRD_RTC_DAY_CNT_VALUE;
  157. break;
  158. case SPRD_RTC_ALARM:
  159. sec_reg = SPRD_RTC_SEC_ALM_VALUE;
  160. min_reg = SPRD_RTC_MIN_ALM_VALUE;
  161. hour_reg = SPRD_RTC_HOUR_ALM_VALUE;
  162. day_reg = SPRD_RTC_DAY_ALM_VALUE;
  163. break;
  164. case SPRD_RTC_AUX_ALARM:
  165. sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
  166. min_reg = SPRD_RTC_MIN_AUXALM_UPD;
  167. hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
  168. day_reg = SPRD_RTC_DAY_AUXALM_UPD;
  169. break;
  170. default:
  171. return -EINVAL;
  172. }
  173. ret = regmap_read(rtc->regmap, rtc->base + sec_reg, &val);
  174. if (ret)
  175. return ret;
  176. sec = val & SPRD_RTC_SEC_MASK;
  177. ret = regmap_read(rtc->regmap, rtc->base + min_reg, &val);
  178. if (ret)
  179. return ret;
  180. min = val & SPRD_RTC_MIN_MASK;
  181. ret = regmap_read(rtc->regmap, rtc->base + hour_reg, &val);
  182. if (ret)
  183. return ret;
  184. hour = val & SPRD_RTC_HOUR_MASK;
  185. ret = regmap_read(rtc->regmap, rtc->base + day_reg, &val);
  186. if (ret)
  187. return ret;
  188. day = val & SPRD_RTC_DAY_MASK;
  189. *secs = (((time64_t)(day * 24) + hour) * 60 + min) * 60 + sec;
  190. return 0;
  191. }
  192. static int sprd_rtc_set_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
  193. time64_t secs)
  194. {
  195. u32 sec_reg, min_reg, hour_reg, day_reg, sts_mask;
  196. u32 sec, min, hour, day, val;
  197. int ret, rem;
  198. /* convert seconds to RTC time format */
  199. day = div_s64_rem(secs, 86400, &rem);
  200. hour = rem / 3600;
  201. rem -= hour * 3600;
  202. min = rem / 60;
  203. sec = rem - min * 60;
  204. switch (type) {
  205. case SPRD_RTC_TIME:
  206. sec_reg = SPRD_RTC_SEC_CNT_UPD;
  207. min_reg = SPRD_RTC_MIN_CNT_UPD;
  208. hour_reg = SPRD_RTC_HOUR_CNT_UPD;
  209. day_reg = SPRD_RTC_DAY_CNT_UPD;
  210. sts_mask = SPRD_RTC_TIME_INT_MASK;
  211. break;
  212. case SPRD_RTC_ALARM:
  213. sec_reg = SPRD_RTC_SEC_ALM_UPD;
  214. min_reg = SPRD_RTC_MIN_ALM_UPD;
  215. hour_reg = SPRD_RTC_HOUR_ALM_UPD;
  216. day_reg = SPRD_RTC_DAY_ALM_UPD;
  217. sts_mask = SPRD_RTC_ALMTIME_INT_MASK;
  218. break;
  219. case SPRD_RTC_AUX_ALARM:
  220. sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
  221. min_reg = SPRD_RTC_MIN_AUXALM_UPD;
  222. hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
  223. day_reg = SPRD_RTC_DAY_AUXALM_UPD;
  224. sts_mask = 0;
  225. break;
  226. default:
  227. return -EINVAL;
  228. }
  229. ret = regmap_write(rtc->regmap, rtc->base + sec_reg, sec);
  230. if (ret)
  231. return ret;
  232. ret = regmap_write(rtc->regmap, rtc->base + min_reg, min);
  233. if (ret)
  234. return ret;
  235. ret = regmap_write(rtc->regmap, rtc->base + hour_reg, hour);
  236. if (ret)
  237. return ret;
  238. ret = regmap_write(rtc->regmap, rtc->base + day_reg, day);
  239. if (ret)
  240. return ret;
  241. if (type == SPRD_RTC_AUX_ALARM)
  242. return 0;
  243. /*
  244. * Since the time and normal alarm registers are put in always-power-on
  245. * region supplied by VDDRTC, then these registers changing time will
  246. * be very long, about 125ms. Thus here we should wait until all
  247. * values are updated successfully.
  248. */
  249. ret = regmap_read_poll_timeout(rtc->regmap,
  250. rtc->base + SPRD_RTC_INT_RAW_STS, val,
  251. ((val & sts_mask) == sts_mask),
  252. SPRD_RTC_POLL_DELAY_US,
  253. SPRD_RTC_POLL_TIMEOUT);
  254. if (ret < 0) {
  255. dev_err(rtc->dev, "set time/alarm values timeout\n");
  256. return ret;
  257. }
  258. return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
  259. sts_mask);
  260. }
  261. static int sprd_rtc_set_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  262. {
  263. struct sprd_rtc *rtc = dev_get_drvdata(dev);
  264. time64_t secs = rtc_tm_to_time64(&alrm->time);
  265. int ret;
  266. /* clear the auxiliary alarm interrupt status */
  267. ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
  268. SPRD_RTC_AUXALM_EN);
  269. if (ret)
  270. return ret;
  271. ret = sprd_rtc_set_secs(rtc, SPRD_RTC_AUX_ALARM, secs);
  272. if (ret)
  273. return ret;
  274. if (alrm->enabled) {
  275. ret = regmap_update_bits(rtc->regmap,
  276. rtc->base + SPRD_RTC_INT_EN,
  277. SPRD_RTC_AUXALM_EN,
  278. SPRD_RTC_AUXALM_EN);
  279. } else {
  280. ret = regmap_update_bits(rtc->regmap,
  281. rtc->base + SPRD_RTC_INT_EN,
  282. SPRD_RTC_AUXALM_EN, 0);
  283. }
  284. return ret;
  285. }
  286. static int sprd_rtc_read_time(struct device *dev, struct rtc_time *tm)
  287. {
  288. struct sprd_rtc *rtc = dev_get_drvdata(dev);
  289. time64_t secs;
  290. int ret;
  291. if (!rtc->valid) {
  292. dev_warn(dev, "RTC values are invalid\n");
  293. return -EINVAL;
  294. }
  295. ret = sprd_rtc_get_secs(rtc, SPRD_RTC_TIME, &secs);
  296. if (ret)
  297. return ret;
  298. rtc_time64_to_tm(secs, tm);
  299. return 0;
  300. }
  301. static int sprd_rtc_set_time(struct device *dev, struct rtc_time *tm)
  302. {
  303. struct sprd_rtc *rtc = dev_get_drvdata(dev);
  304. time64_t secs = rtc_tm_to_time64(tm);
  305. int ret;
  306. ret = sprd_rtc_set_secs(rtc, SPRD_RTC_TIME, secs);
  307. if (ret)
  308. return ret;
  309. if (!rtc->valid) {
  310. /* Clear RTC power status firstly */
  311. ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
  312. SPRD_RTC_POWER_STS_CLEAR);
  313. if (ret)
  314. return ret;
  315. /*
  316. * Set RTC power status to indicate now RTC has valid time
  317. * values.
  318. */
  319. ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL,
  320. SPRD_RTC_POWER_STS_VALID);
  321. if (ret)
  322. return ret;
  323. rtc->valid = true;
  324. }
  325. return 0;
  326. }
  327. static int sprd_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  328. {
  329. struct sprd_rtc *rtc = dev_get_drvdata(dev);
  330. time64_t secs;
  331. int ret;
  332. u32 val;
  333. /*
  334. * The RTC core checks to see if there is an alarm already set in RTC
  335. * hardware, and we always read the normal alarm at this time.
  336. */
  337. ret = sprd_rtc_get_secs(rtc, SPRD_RTC_ALARM, &secs);
  338. if (ret)
  339. return ret;
  340. rtc_time64_to_tm(secs, &alrm->time);
  341. ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
  342. if (ret)
  343. return ret;
  344. alrm->enabled = !!(val & SPRD_RTC_ALARM_EN);
  345. ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
  346. if (ret)
  347. return ret;
  348. alrm->pending = !!(val & SPRD_RTC_ALARM_EN);
  349. return 0;
  350. }
  351. static int sprd_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  352. {
  353. struct sprd_rtc *rtc = dev_get_drvdata(dev);
  354. time64_t secs = rtc_tm_to_time64(&alrm->time);
  355. struct rtc_time aie_time =
  356. rtc_ktime_to_tm(rtc->rtc->aie_timer.node.expires);
  357. int ret;
  358. /*
  359. * We have 2 groups alarms: normal alarm and auxiliary alarm. Since
  360. * both normal alarm event and auxiliary alarm event can wake up system
  361. * from deep sleep, but only alarm event can power up system from power
  362. * down status. Moreover we do not need to poll about 125ms when
  363. * updating auxiliary alarm registers. Thus we usually set auxiliary
  364. * alarm when wake up system from deep sleep, and for other scenarios,
  365. * we should set normal alarm with polling status.
  366. *
  367. * So here we check if the alarm time is set by aie_timer, if yes, we
  368. * should set normal alarm, if not, we should set auxiliary alarm which
  369. * means it is just a wake event.
  370. */
  371. if (!rtc->rtc->aie_timer.enabled || rtc_tm_sub(&aie_time, &alrm->time))
  372. return sprd_rtc_set_aux_alarm(dev, alrm);
  373. /* clear the alarm interrupt status firstly */
  374. ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
  375. SPRD_RTC_ALARM_EN);
  376. if (ret)
  377. return ret;
  378. ret = sprd_rtc_set_secs(rtc, SPRD_RTC_ALARM, secs);
  379. if (ret)
  380. return ret;
  381. if (alrm->enabled) {
  382. ret = regmap_update_bits(rtc->regmap,
  383. rtc->base + SPRD_RTC_INT_EN,
  384. SPRD_RTC_ALARM_EN,
  385. SPRD_RTC_ALARM_EN);
  386. if (ret)
  387. return ret;
  388. /* unlock the alarm to enable the alarm function. */
  389. ret = sprd_rtc_lock_alarm(rtc, false);
  390. } else {
  391. regmap_update_bits(rtc->regmap,
  392. rtc->base + SPRD_RTC_INT_EN,
  393. SPRD_RTC_ALARM_EN, 0);
  394. /*
  395. * Lock the alarm function in case fake alarm event will power
  396. * up systems.
  397. */
  398. ret = sprd_rtc_lock_alarm(rtc, true);
  399. }
  400. return ret;
  401. }
  402. static int sprd_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  403. {
  404. struct sprd_rtc *rtc = dev_get_drvdata(dev);
  405. int ret;
  406. if (enabled) {
  407. ret = regmap_update_bits(rtc->regmap,
  408. rtc->base + SPRD_RTC_INT_EN,
  409. SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN,
  410. SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN);
  411. if (ret)
  412. return ret;
  413. ret = sprd_rtc_lock_alarm(rtc, false);
  414. } else {
  415. regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
  416. SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN, 0);
  417. ret = sprd_rtc_lock_alarm(rtc, true);
  418. }
  419. return ret;
  420. }
  421. static const struct rtc_class_ops sprd_rtc_ops = {
  422. .read_time = sprd_rtc_read_time,
  423. .set_time = sprd_rtc_set_time,
  424. .read_alarm = sprd_rtc_read_alarm,
  425. .set_alarm = sprd_rtc_set_alarm,
  426. .alarm_irq_enable = sprd_rtc_alarm_irq_enable,
  427. };
  428. static irqreturn_t sprd_rtc_handler(int irq, void *dev_id)
  429. {
  430. struct sprd_rtc *rtc = dev_id;
  431. int ret;
  432. ret = sprd_rtc_clear_alarm_ints(rtc);
  433. if (ret)
  434. return IRQ_RETVAL(ret);
  435. rtc_update_irq(rtc->rtc, 1, RTC_AF | RTC_IRQF);
  436. return IRQ_HANDLED;
  437. }
  438. static int sprd_rtc_check_power_down(struct sprd_rtc *rtc)
  439. {
  440. u32 val;
  441. int ret;
  442. ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_PWR_STS, &val);
  443. if (ret)
  444. return ret;
  445. /*
  446. * If the RTC power status value is SPRD_RTC_POWER_RESET_VALUE, which
  447. * means the RTC has been powered down, so the RTC time values are
  448. * invalid.
  449. */
  450. rtc->valid = val != SPRD_RTC_POWER_RESET_VALUE;
  451. return 0;
  452. }
  453. static int sprd_rtc_check_alarm_int(struct sprd_rtc *rtc)
  454. {
  455. u32 val;
  456. int ret;
  457. ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
  458. if (ret)
  459. return ret;
  460. /*
  461. * The SPRD_RTC_INT_EN register is not put in always-power-on region
  462. * supplied by VDDRTC, so we should check if we need enable the alarm
  463. * interrupt when system booting.
  464. *
  465. * If we have set SPRD_RTC_POWEROFF_ALM_FLAG which is saved in
  466. * always-power-on region, that means we have set one alarm last time,
  467. * so we should enable the alarm interrupt to help RTC core to see if
  468. * there is an alarm already set in RTC hardware.
  469. */
  470. if (!(val & SPRD_RTC_POWEROFF_ALM_FLAG))
  471. return 0;
  472. return regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
  473. SPRD_RTC_ALARM_EN, SPRD_RTC_ALARM_EN);
  474. }
  475. static int sprd_rtc_probe(struct platform_device *pdev)
  476. {
  477. struct device_node *node = pdev->dev.of_node;
  478. struct sprd_rtc *rtc;
  479. int ret;
  480. rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
  481. if (!rtc)
  482. return -ENOMEM;
  483. rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
  484. if (!rtc->regmap)
  485. return -ENODEV;
  486. ret = of_property_read_u32(node, "reg", &rtc->base);
  487. if (ret) {
  488. dev_err(&pdev->dev, "failed to get RTC base address\n");
  489. return ret;
  490. }
  491. rtc->irq = platform_get_irq(pdev, 0);
  492. if (rtc->irq < 0)
  493. return rtc->irq;
  494. rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
  495. if (IS_ERR(rtc->rtc))
  496. return PTR_ERR(rtc->rtc);
  497. rtc->dev = &pdev->dev;
  498. platform_set_drvdata(pdev, rtc);
  499. /* check if we need set the alarm interrupt */
  500. ret = sprd_rtc_check_alarm_int(rtc);
  501. if (ret) {
  502. dev_err(&pdev->dev, "failed to check RTC alarm interrupt\n");
  503. return ret;
  504. }
  505. /* check if RTC time values are valid */
  506. ret = sprd_rtc_check_power_down(rtc);
  507. if (ret) {
  508. dev_err(&pdev->dev, "failed to check RTC time values\n");
  509. return ret;
  510. }
  511. ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
  512. sprd_rtc_handler,
  513. IRQF_ONESHOT | IRQF_EARLY_RESUME,
  514. pdev->name, rtc);
  515. if (ret < 0) {
  516. dev_err(&pdev->dev, "failed to request RTC irq\n");
  517. return ret;
  518. }
  519. device_init_wakeup(&pdev->dev, 1);
  520. rtc->rtc->ops = &sprd_rtc_ops;
  521. rtc->rtc->range_min = 0;
  522. rtc->rtc->range_max = 5662310399LL;
  523. ret = devm_rtc_register_device(rtc->rtc);
  524. if (ret) {
  525. device_init_wakeup(&pdev->dev, 0);
  526. return ret;
  527. }
  528. return 0;
  529. }
  530. static const struct of_device_id sprd_rtc_of_match[] = {
  531. { .compatible = "sprd,sc2731-rtc", },
  532. { },
  533. };
  534. MODULE_DEVICE_TABLE(of, sprd_rtc_of_match);
  535. static struct platform_driver sprd_rtc_driver = {
  536. .driver = {
  537. .name = "sprd-rtc",
  538. .of_match_table = sprd_rtc_of_match,
  539. },
  540. .probe = sprd_rtc_probe,
  541. };
  542. module_platform_driver(sprd_rtc_driver);
  543. MODULE_LICENSE("GPL v2");
  544. MODULE_DESCRIPTION("Spreadtrum RTC Device Driver");
  545. MODULE_AUTHOR("Baolin Wang <[email protected]>");