rv3029.c 12 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * (C) Copyright 2018 Theobroma Systems Design und Consulting GmbH
  4. *
  5. * Based on a the Linux rtc-rv3029c2.c driver written by:
  6. * Gregory Hermant <gregory.hermant@calao-systems.com>
  7. * Michael Buesch <m@bues.ch>
  8. */
  9. #include <common.h>
  10. #include <command.h>
  11. #include <dm.h>
  12. #include <eeprom.h>
  13. #include <i2c.h>
  14. #include <log.h>
  15. #include <rtc.h>
  16. #include <dm/device_compat.h>
  17. #include <linux/bitops.h>
  18. #include <linux/delay.h>
  19. #define RTC_RV3029_PAGE_LEN 7
  20. /* control section */
  21. #define RV3029_ONOFF_CTRL 0x00
  22. #define RV3029_ONOFF_CTRL_WE BIT(0)
  23. #define RV3029_ONOFF_CTRL_TE BIT(1)
  24. #define RV3029_ONOFF_CTRL_TAR BIT(2)
  25. #define RV3029_ONOFF_CTRL_EERE BIT(3)
  26. #define RV3029_ONOFF_CTRL_SRON BIT(4)
  27. #define RV3029_ONOFF_CTRL_TD0 BIT(5)
  28. #define RV3029_ONOFF_CTRL_TD1 BIT(6)
  29. #define RV3029_ONOFF_CTRL_CLKINT BIT(7)
  30. #define RV3029_IRQ_CTRL 0x01
  31. #define RV3029_IRQ_CTRL_AIE BIT(0)
  32. #define RV3029_IRQ_CTRL_TIE BIT(1)
  33. #define RV3029_IRQ_CTRL_V1IE BIT(2)
  34. #define RV3029_IRQ_CTRL_V2IE BIT(3)
  35. #define RV3029_IRQ_CTRL_SRIE BIT(4)
  36. #define RV3029_IRQ_FLAGS 0x02
  37. #define RV3029_IRQ_FLAGS_AF BIT(0)
  38. #define RV3029_IRQ_FLAGS_TF BIT(1)
  39. #define RV3029_IRQ_FLAGS_V1IF BIT(2)
  40. #define RV3029_IRQ_FLAGS_V2IF BIT(3)
  41. #define RV3029_IRQ_FLAGS_SRF BIT(4)
  42. #define RV3029_STATUS 0x03
  43. #define RV3029_STATUS_VLOW1 BIT(2)
  44. #define RV3029_STATUS_VLOW2 BIT(3)
  45. #define RV3029_STATUS_SR BIT(4)
  46. #define RV3029_STATUS_PON BIT(5)
  47. #define RV3029_STATUS_EEBUSY BIT(7)
  48. #define RV3029_RST_CTRL 0x04
  49. #define RV3029_RST_CTRL_SYSR BIT(4)
  50. #define RV3029_CONTROL_SECTION_LEN 0x05
  51. /* watch section */
  52. #define RV3029_W_SEC 0x08
  53. #define RV3029_W_MINUTES 0x09
  54. #define RV3029_W_HOURS 0x0A
  55. #define RV3029_REG_HR_12_24 BIT(6) /* 24h/12h mode */
  56. #define RV3029_REG_HR_PM BIT(5) /* PM/AM bit in 12h mode */
  57. #define RV3029_W_DATE 0x0B
  58. #define RV3029_W_DAYS 0x0C
  59. #define RV3029_W_MONTHS 0x0D
  60. #define RV3029_W_YEARS 0x0E
  61. /* eeprom control section */
  62. #define RV3029_CONTROL_E2P_EECTRL 0x30
  63. #define RV3029_TRICKLE_1K BIT(4) /* 1.5K resistance */
  64. #define RV3029_TRICKLE_5K BIT(5) /* 5K resistance */
  65. #define RV3029_TRICKLE_20K BIT(6) /* 20K resistance */
  66. #define RV3029_TRICKLE_80K BIT(7) /* 80K resistance */
  67. #define RV3029_TRICKLE_MASK (RV3029_TRICKLE_1K |\
  68. RV3029_TRICKLE_5K |\
  69. RV3029_TRICKLE_20K |\
  70. RV3029_TRICKLE_80K)
  71. #define RV3029_TRICKLE_SHIFT 4
  72. static int rv3029_rtc_get(struct udevice *dev, struct rtc_time *tm)
  73. {
  74. u8 regs[RTC_RV3029_PAGE_LEN];
  75. int ret;
  76. ret = dm_i2c_read(dev, RV3029_W_SEC, regs, sizeof(regs));
  77. if (ret < 0) {
  78. printf("%s: error reading RTC: %x\n", __func__, ret);
  79. return -EIO;
  80. }
  81. tm->tm_sec = bcd2bin(regs[RV3029_W_SEC - RV3029_W_SEC]);
  82. tm->tm_min = bcd2bin(regs[RV3029_W_MINUTES - RV3029_W_SEC]);
  83. /* HR field has a more complex interpretation */
  84. {
  85. const u8 _hr = regs[RV3029_W_HOURS - RV3029_W_SEC];
  86. if (_hr & RV3029_REG_HR_12_24) {
  87. /* 12h format */
  88. tm->tm_hour = bcd2bin(_hr & 0x1f);
  89. if (_hr & RV3029_REG_HR_PM) /* PM flag set */
  90. tm->tm_hour += 12;
  91. } else {
  92. /* 24h format */
  93. tm->tm_hour = bcd2bin(_hr & 0x3f);
  94. }
  95. }
  96. tm->tm_mday = bcd2bin(regs[RV3029_W_DATE - RV3029_W_SEC]);
  97. tm->tm_mon = bcd2bin(regs[RV3029_W_MONTHS - RV3029_W_SEC]) - 1;
  98. /* RTC supports only years > 1999 */
  99. tm->tm_year = bcd2bin(regs[RV3029_W_YEARS - RV3029_W_SEC]) + 2000;
  100. tm->tm_wday = bcd2bin(regs[RV3029_W_DAYS - RV3029_W_SEC]) - 1;
  101. tm->tm_yday = 0;
  102. tm->tm_isdst = 0;
  103. debug("%s: %4d-%02d-%02d (wday=%d) %2d:%02d:%02d\n",
  104. __func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
  105. tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
  106. return 0;
  107. }
  108. static int rv3029_rtc_set(struct udevice *dev, const struct rtc_time *tm)
  109. {
  110. u8 regs[RTC_RV3029_PAGE_LEN];
  111. debug("%s: %4d-%02d-%02d (wday=%d( %2d:%02d:%02d\n",
  112. __func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
  113. tm->tm_wday, tm->tm_hour, tm->tm_min, tm->tm_sec);
  114. if (tm->tm_year < 2000) {
  115. printf("%s: year %d (before 2000) not supported\n",
  116. __func__, tm->tm_year);
  117. return -EINVAL;
  118. }
  119. regs[RV3029_W_SEC - RV3029_W_SEC] = bin2bcd(tm->tm_sec);
  120. regs[RV3029_W_MINUTES - RV3029_W_SEC] = bin2bcd(tm->tm_min);
  121. regs[RV3029_W_HOURS - RV3029_W_SEC] = bin2bcd(tm->tm_hour);
  122. regs[RV3029_W_DATE - RV3029_W_SEC] = bin2bcd(tm->tm_mday);
  123. regs[RV3029_W_MONTHS - RV3029_W_SEC] = bin2bcd(tm->tm_mon + 1);
  124. regs[RV3029_W_DAYS - RV3029_W_SEC] = bin2bcd(tm->tm_wday + 1) & 0x7;
  125. regs[RV3029_W_YEARS - RV3029_W_SEC] = bin2bcd(tm->tm_year - 2000);
  126. return dm_i2c_write(dev, RV3029_W_SEC, regs, sizeof(regs));
  127. }
  128. static int rv3029_rtc_reset(struct udevice *dev)
  129. {
  130. u8 ctrl = RV3029_RST_CTRL_SYSR;
  131. unsigned long start;
  132. const unsigned long timeout_ms = 10000;
  133. int ret;
  134. /* trigger the system-reset */
  135. ret = dm_i2c_write(dev, RV3029_RST_CTRL, &ctrl, 1);
  136. if (ret < 0)
  137. return -EIO;
  138. /* wait for the system-reset to complete */
  139. start = get_timer(0);
  140. do {
  141. if (get_timer(start) > timeout_ms)
  142. return -ETIMEDOUT;
  143. ret = dm_i2c_read(dev, RV3029_RST_CTRL, &ctrl, 1);
  144. if (ret < 0)
  145. return -EIO;
  146. } while (ctrl & RV3029_RST_CTRL_SYSR);
  147. return 0;
  148. }
  149. static int rv3029_rtc_read8(struct udevice *dev, unsigned int reg)
  150. {
  151. u8 data;
  152. int ret;
  153. ret = dm_i2c_read(dev, reg, &data, sizeof(data));
  154. return ret < 0 ? ret : data;
  155. }
  156. static int rv3029_rtc_write8(struct udevice *dev, unsigned int reg, int val)
  157. {
  158. u8 data = val;
  159. return dm_i2c_write(dev, reg, &data, 1);
  160. }
  161. #if defined(OF_CONTROL)
  162. static int rv3029_get_sr(struct udevice *dev, u8 *buf)
  163. {
  164. int ret = dm_i2c_read(dev, RV3029_STATUS, buf, 1);
  165. if (ret < 0)
  166. return -EIO;
  167. dev_dbg(dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]);
  168. return 0;
  169. }
  170. static int rv3029_set_sr(struct udevice *dev, u8 val)
  171. {
  172. int ret;
  173. ret = dm_i2c_read(dev, RV3029_STATUS, &val, 1);
  174. if (ret < 0)
  175. return -EIO;
  176. dev_dbg(dev, "status = 0x%.2x (%d)\n", val, val);
  177. return 0;
  178. }
  179. static int rv3029_eeprom_busywait(struct udevice *dev)
  180. {
  181. int i, ret;
  182. u8 sr;
  183. for (i = 100; i > 0; i--) {
  184. ret = rv3029_get_sr(dev, &sr);
  185. if (ret < 0)
  186. break;
  187. if (!(sr & RV3029_STATUS_EEBUSY))
  188. break;
  189. udelay(10000);
  190. }
  191. if (i <= 0) {
  192. dev_err(dev, "EEPROM busy wait timeout.\n");
  193. return -ETIMEDOUT;
  194. }
  195. return ret;
  196. }
  197. static int rv3029_update_bits(struct udevice *dev, u8 reg, u8 mask, u8 set)
  198. {
  199. u8 buf;
  200. int ret;
  201. ret = dm_i2c_read(dev, reg, &buf, 1);
  202. if (ret < 0)
  203. return ret;
  204. if ((buf & mask) == (set && mask))
  205. return 0;
  206. buf = (buf & ~mask) | (set & mask);
  207. ret = dm_i2c_read(dev, reg, &buf, 1);
  208. if (ret < 0)
  209. return ret;
  210. return 0;
  211. }
  212. static int rv3029_eeprom_exit(struct udevice *dev)
  213. {
  214. /* Re-enable eeprom refresh */
  215. return rv3029_update_bits(dev, RV3029_ONOFF_CTRL,
  216. RV3029_ONOFF_CTRL_EERE,
  217. RV3029_ONOFF_CTRL_EERE);
  218. }
  219. static int rv3029_eeprom_enter(struct udevice *dev)
  220. {
  221. int ret;
  222. u8 sr;
  223. /* Check whether we are in the allowed voltage range. */
  224. ret = rv3029_get_sr(dev, &sr);
  225. if (ret < 0)
  226. return ret;
  227. if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
  228. /* We clear the bits and retry once just in case
  229. * we had a brown out in early startup.
  230. */
  231. sr &= ~RV3029_STATUS_VLOW1;
  232. sr &= ~RV3029_STATUS_VLOW2;
  233. ret = rv3029_set_sr(dev, sr);
  234. if (ret < 0)
  235. return ret;
  236. udelay(10000);
  237. ret = rv3029_get_sr(dev, &sr);
  238. if (ret < 0)
  239. return ret;
  240. if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
  241. dev_err(dev, "Supply voltage is too low to safely access the EEPROM.\n");
  242. return -ENODEV;
  243. }
  244. }
  245. /* Disable eeprom refresh. */
  246. ret = rv3029_update_bits(dev,
  247. RV3029_ONOFF_CTRL, RV3029_ONOFF_CTRL_EERE, 0);
  248. if (ret < 0)
  249. return ret;
  250. /* Wait for any previous eeprom accesses to finish. */
  251. ret = rv3029_eeprom_busywait(dev);
  252. if (ret < 0)
  253. rv3029_eeprom_exit(dev);
  254. return ret;
  255. }
  256. static int rv3029_eeprom_read(struct udevice *dev, u8 reg,
  257. u8 buf[], size_t len)
  258. {
  259. int ret, err;
  260. err = rv3029_eeprom_enter(dev);
  261. if (err < 0)
  262. return err;
  263. ret = dm_i2c_read(dev, reg, buf, len);
  264. err = rv3029_eeprom_exit(dev);
  265. if (err < 0)
  266. return err;
  267. return ret;
  268. }
  269. static int rv3029_eeprom_write(struct udevice *dev, u8 reg,
  270. u8 const buf[], size_t len)
  271. {
  272. int ret;
  273. size_t i;
  274. u8 tmp;
  275. ret = rv3029_eeprom_enter(dev);
  276. if (ret < 0)
  277. return ret;
  278. for (i = 0; i < len; i++, reg++) {
  279. ret = dm_i2c_read(dev, reg, &tmp, 1);
  280. if (ret < 0)
  281. break;
  282. if (tmp != buf[i]) {
  283. ret = dm_i2c_write(dev, reg, &buf[i], 1);
  284. if (ret < 0)
  285. break;
  286. }
  287. ret = rv3029_eeprom_busywait(dev);
  288. if (ret < 0)
  289. break;
  290. }
  291. ret = rv3029_eeprom_exit(dev);
  292. if (ret < 0)
  293. return ret;
  294. return 0;
  295. }
  296. static int rv3029_eeprom_update_bits(struct udevice *dev,
  297. u8 reg, u8 mask, u8 set)
  298. {
  299. u8 buf;
  300. int ret;
  301. ret = rv3029_eeprom_read(dev, reg, &buf, 1);
  302. if (ret < 0)
  303. return ret;
  304. /*
  305. * If the EEPROM already reads the correct bitpattern, we don't need
  306. * to update it.
  307. */
  308. if ((buf & mask) == (set & mask))
  309. return 0;
  310. buf = (buf & ~mask) | (set & mask);
  311. ret = rv3029_eeprom_write(dev, reg, &buf, 1);
  312. if (ret < 0)
  313. return ret;
  314. return 0;
  315. }
  316. static void rv3029_trickle_config(struct udevice *dev)
  317. {
  318. static const struct rv3029_trickle_tab_elem {
  319. u32 r; /* resistance in ohms */
  320. u8 conf; /* trickle config bits */
  321. } rv3029_trickle_tab[] = {
  322. {
  323. .r = 1076,
  324. .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
  325. RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
  326. }, {
  327. .r = 1091,
  328. .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
  329. RV3029_TRICKLE_20K,
  330. }, {
  331. .r = 1137,
  332. .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K |
  333. RV3029_TRICKLE_80K,
  334. }, {
  335. .r = 1154,
  336. .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_5K,
  337. }, {
  338. .r = 1371,
  339. .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K |
  340. RV3029_TRICKLE_80K,
  341. }, {
  342. .r = 1395,
  343. .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_20K,
  344. }, {
  345. .r = 1472,
  346. .conf = RV3029_TRICKLE_1K | RV3029_TRICKLE_80K,
  347. }, {
  348. .r = 1500,
  349. .conf = RV3029_TRICKLE_1K,
  350. }, {
  351. .r = 3810,
  352. .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K |
  353. RV3029_TRICKLE_80K,
  354. }, {
  355. .r = 4000,
  356. .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_20K,
  357. }, {
  358. .r = 4706,
  359. .conf = RV3029_TRICKLE_5K | RV3029_TRICKLE_80K,
  360. }, {
  361. .r = 5000,
  362. .conf = RV3029_TRICKLE_5K,
  363. }, {
  364. .r = 16000,
  365. .conf = RV3029_TRICKLE_20K | RV3029_TRICKLE_80K,
  366. }, {
  367. .r = 20000,
  368. .conf = RV3029_TRICKLE_20K,
  369. }, {
  370. .r = 80000,
  371. .conf = RV3029_TRICKLE_80K,
  372. },
  373. };
  374. int err;
  375. u32 ohms;
  376. u8 trickle_set_bits = 0;
  377. /* Configure the trickle charger. */
  378. err = dev_read_u32(dev, "trickle-resistor-ohms", &ohms);
  379. if (!err) {
  380. /* Find trickle-charger config */
  381. for (int i = 0; i < ARRAY_SIZE(rv3029_trickle_tab); i++)
  382. if (rv3029_trickle_tab[i].r >= ohms) {
  383. dev_dbg(dev, "trickle charger at %d ohms\n",
  384. rv3029_trickle_tab[i].r);
  385. trickle_set_bits = rv3029_trickle_tab[i].conf;
  386. break;
  387. }
  388. }
  389. dev_dbg(dev, "trickle charger config 0x%x\n", trickle_set_bits);
  390. err = rv3029_eeprom_update_bits(dev, RV3029_CONTROL_E2P_EECTRL,
  391. RV3029_TRICKLE_MASK,
  392. trickle_set_bits);
  393. if (err < 0)
  394. dev_dbg(dev, "failed to update trickle charger\n");
  395. }
  396. #else
  397. static inline void rv3029_trickle_config(struct udevice *dev)
  398. {
  399. }
  400. #endif
  401. static int rv3029_probe(struct udevice *dev)
  402. {
  403. i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
  404. DM_I2C_CHIP_WR_ADDRESS);
  405. rv3029_trickle_config(dev);
  406. return 0;
  407. }
  408. static const struct rtc_ops rv3029_rtc_ops = {
  409. .get = rv3029_rtc_get,
  410. .set = rv3029_rtc_set,
  411. .read8 = rv3029_rtc_read8,
  412. .write8 = rv3029_rtc_write8,
  413. .reset = rv3029_rtc_reset,
  414. };
  415. static const struct udevice_id rv3029_rtc_ids[] = {
  416. { .compatible = "mc,rv3029" },
  417. { .compatible = "mc,rv3029c2" },
  418. { }
  419. };
  420. U_BOOT_DRIVER(rtc_rv3029) = {
  421. .name = "rtc-rv3029",
  422. .id = UCLASS_RTC,
  423. .probe = rv3029_probe,
  424. .of_match = rv3029_rtc_ids,
  425. .ops = &rv3029_rtc_ops,
  426. };