ds1307.c 9.2 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * (C) Copyright 2001, 2002, 2003
  4. * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  5. * Keith Outwater, keith_outwater@mvis.com`
  6. * Steven Scholz, steven.scholz@imc-berlin.de
  7. */
  8. /*
  9. * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
  10. * DS1307 and DS1338/9 Real Time Clock (RTC).
  11. *
  12. * based on ds1337.c
  13. */
  14. #include <common.h>
  15. #include <command.h>
  16. #include <dm.h>
  17. #include <log.h>
  18. #include <rtc.h>
  19. #include <i2c.h>
  20. enum ds_type {
  21. ds_1307,
  22. ds_1337,
  23. ds_1340,
  24. m41t11,
  25. mcp794xx,
  26. };
  27. /*
  28. * RTC register addresses
  29. */
  30. #define RTC_SEC_REG_ADDR 0x00
  31. #define RTC_MIN_REG_ADDR 0x01
  32. #define RTC_HR_REG_ADDR 0x02
  33. #define RTC_DAY_REG_ADDR 0x03
  34. #define RTC_DATE_REG_ADDR 0x04
  35. #define RTC_MON_REG_ADDR 0x05
  36. #define RTC_YR_REG_ADDR 0x06
  37. #define RTC_CTL_REG_ADDR 0x07
  38. #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
  39. #define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */
  40. #define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */
  41. #define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */
  42. #define RTC_CTL_BIT_OUT 0x80 /* Output Control */
  43. /* MCP7941X-specific bits */
  44. #define MCP7941X_BIT_ST 0x80
  45. #define MCP7941X_BIT_VBATEN 0x08
  46. #ifndef CONFIG_DM_RTC
  47. /*---------------------------------------------------------------------*/
  48. #undef DEBUG_RTC
  49. #ifdef DEBUG_RTC
  50. #define DEBUGR(fmt, args...) printf(fmt, ##args)
  51. #else
  52. #define DEBUGR(fmt, args...)
  53. #endif
  54. /*---------------------------------------------------------------------*/
  55. #ifndef CONFIG_SYS_I2C_RTC_ADDR
  56. # define CONFIG_SYS_I2C_RTC_ADDR 0x68
  57. #endif
  58. #if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
  59. # error The DS1307 is specified only up to 100kHz!
  60. #endif
  61. static uchar rtc_read (uchar reg);
  62. static void rtc_write (uchar reg, uchar val);
  63. /*
  64. * Get the current time from the RTC
  65. */
  66. int rtc_get (struct rtc_time *tmp)
  67. {
  68. int rel = 0;
  69. uchar sec, min, hour, mday, wday, mon, year;
  70. #ifdef CONFIG_RTC_MCP79411
  71. read_rtc:
  72. #endif
  73. sec = rtc_read (RTC_SEC_REG_ADDR);
  74. min = rtc_read (RTC_MIN_REG_ADDR);
  75. hour = rtc_read (RTC_HR_REG_ADDR);
  76. wday = rtc_read (RTC_DAY_REG_ADDR);
  77. mday = rtc_read (RTC_DATE_REG_ADDR);
  78. mon = rtc_read (RTC_MON_REG_ADDR);
  79. year = rtc_read (RTC_YR_REG_ADDR);
  80. DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
  81. "hr: %02x min: %02x sec: %02x\n",
  82. year, mon, mday, wday, hour, min, sec);
  83. #ifdef CONFIG_RTC_DS1307
  84. if (sec & RTC_SEC_BIT_CH) {
  85. printf ("### Warning: RTC oscillator has stopped\n");
  86. /* clear the CH flag */
  87. rtc_write (RTC_SEC_REG_ADDR,
  88. rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH);
  89. rel = -1;
  90. }
  91. #endif
  92. #ifdef CONFIG_RTC_MCP79411
  93. /* make sure that the backup battery is enabled */
  94. if (!(wday & MCP7941X_BIT_VBATEN)) {
  95. rtc_write(RTC_DAY_REG_ADDR,
  96. wday | MCP7941X_BIT_VBATEN);
  97. }
  98. /* clock halted? turn it on, so clock can tick. */
  99. if (!(sec & MCP7941X_BIT_ST)) {
  100. rtc_write(RTC_SEC_REG_ADDR, MCP7941X_BIT_ST);
  101. printf("Started RTC\n");
  102. goto read_rtc;
  103. }
  104. #endif
  105. tmp->tm_sec = bcd2bin (sec & 0x7F);
  106. tmp->tm_min = bcd2bin (min & 0x7F);
  107. tmp->tm_hour = bcd2bin (hour & 0x3F);
  108. tmp->tm_mday = bcd2bin (mday & 0x3F);
  109. tmp->tm_mon = bcd2bin (mon & 0x1F);
  110. tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
  111. tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
  112. tmp->tm_yday = 0;
  113. tmp->tm_isdst= 0;
  114. DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  115. tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  116. tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  117. return rel;
  118. }
  119. /*
  120. * Set the RTC
  121. */
  122. int rtc_set (struct rtc_time *tmp)
  123. {
  124. DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  125. tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  126. tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  127. if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
  128. printf("WARNING: year should be between 1970 and 2069!\n");
  129. rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
  130. rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
  131. #ifdef CONFIG_RTC_MCP79411
  132. rtc_write (RTC_DAY_REG_ADDR,
  133. bin2bcd (tmp->tm_wday + 1) | MCP7941X_BIT_VBATEN);
  134. #else
  135. rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
  136. #endif
  137. rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
  138. rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
  139. rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
  140. #ifdef CONFIG_RTC_MCP79411
  141. rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec) | MCP7941X_BIT_ST);
  142. #else
  143. rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
  144. #endif
  145. return 0;
  146. }
  147. /*
  148. * Reset the RTC. We setting the date back to 1970-01-01.
  149. * We also enable the oscillator output on the SQW/OUT pin and program
  150. * it for 32,768 Hz output. Note that according to the datasheet, turning
  151. * on the square wave output increases the current drain on the backup
  152. * battery to something between 480nA and 800nA.
  153. */
  154. void rtc_reset (void)
  155. {
  156. rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
  157. rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0);
  158. }
  159. /*
  160. * Helper functions
  161. */
  162. static
  163. uchar rtc_read (uchar reg)
  164. {
  165. return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
  166. }
  167. static void rtc_write (uchar reg, uchar val)
  168. {
  169. i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
  170. }
  171. #endif /* !CONFIG_DM_RTC */
  172. #ifdef CONFIG_DM_RTC
  173. static int ds1307_rtc_set(struct udevice *dev, const struct rtc_time *tm)
  174. {
  175. int ret;
  176. uchar buf[7];
  177. enum ds_type type = dev_get_driver_data(dev);
  178. debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  179. tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
  180. tm->tm_hour, tm->tm_min, tm->tm_sec);
  181. if (tm->tm_year < 1970 || tm->tm_year > 2069)
  182. printf("WARNING: year should be between 1970 and 2069!\n");
  183. buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
  184. buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
  185. buf[RTC_DAY_REG_ADDR] = bin2bcd(tm->tm_wday + 1);
  186. buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
  187. buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
  188. buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
  189. buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
  190. if (type == mcp794xx) {
  191. buf[RTC_DAY_REG_ADDR] |= MCP7941X_BIT_VBATEN;
  192. buf[RTC_SEC_REG_ADDR] |= MCP7941X_BIT_ST;
  193. }
  194. ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
  195. if (ret < 0)
  196. return ret;
  197. return 0;
  198. }
  199. static int ds1307_rtc_get(struct udevice *dev, struct rtc_time *tm)
  200. {
  201. int ret;
  202. uchar buf[7];
  203. enum ds_type type = dev_get_driver_data(dev);
  204. read_rtc:
  205. ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
  206. if (ret < 0)
  207. return ret;
  208. if (type == ds_1307) {
  209. if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) {
  210. printf("### Warning: RTC oscillator has stopped\n");
  211. /* clear the CH flag */
  212. buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH;
  213. dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
  214. buf[RTC_SEC_REG_ADDR]);
  215. return -1;
  216. }
  217. }
  218. if (type == m41t11) {
  219. /* clock halted? turn it on, so clock can tick. */
  220. if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) {
  221. buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH;
  222. dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
  223. MCP7941X_BIT_ST);
  224. dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
  225. buf[RTC_SEC_REG_ADDR]);
  226. goto read_rtc;
  227. }
  228. }
  229. if (type == mcp794xx) {
  230. /* make sure that the backup battery is enabled */
  231. if (!(buf[RTC_DAY_REG_ADDR] & MCP7941X_BIT_VBATEN)) {
  232. dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR,
  233. buf[RTC_DAY_REG_ADDR] |
  234. MCP7941X_BIT_VBATEN);
  235. }
  236. /* clock halted? turn it on, so clock can tick. */
  237. if (!(buf[RTC_SEC_REG_ADDR] & MCP7941X_BIT_ST)) {
  238. dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
  239. MCP7941X_BIT_ST);
  240. printf("Started RTC\n");
  241. goto read_rtc;
  242. }
  243. }
  244. tm->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
  245. tm->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
  246. tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
  247. tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
  248. tm->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
  249. tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) +
  250. (bcd2bin(buf[RTC_YR_REG_ADDR]) >= 70 ?
  251. 1900 : 2000);
  252. tm->tm_wday = bcd2bin((buf[RTC_DAY_REG_ADDR] - 1) & 0x07);
  253. tm->tm_yday = 0;
  254. tm->tm_isdst = 0;
  255. debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  256. tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
  257. tm->tm_hour, tm->tm_min, tm->tm_sec);
  258. return 0;
  259. }
  260. static int ds1307_rtc_reset(struct udevice *dev)
  261. {
  262. int ret;
  263. /* clear Clock Halt */
  264. ret = dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, 0x00);
  265. if (ret < 0)
  266. return ret;
  267. ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR,
  268. RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 |
  269. RTC_CTL_BIT_RS0);
  270. if (ret < 0)
  271. return ret;
  272. return 0;
  273. }
  274. static int ds1307_probe(struct udevice *dev)
  275. {
  276. i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
  277. DM_I2C_CHIP_WR_ADDRESS);
  278. return 0;
  279. }
  280. static const struct rtc_ops ds1307_rtc_ops = {
  281. .get = ds1307_rtc_get,
  282. .set = ds1307_rtc_set,
  283. .reset = ds1307_rtc_reset,
  284. };
  285. static const struct udevice_id ds1307_rtc_ids[] = {
  286. { .compatible = "dallas,ds1307", .data = ds_1307 },
  287. { .compatible = "dallas,ds1337", .data = ds_1337 },
  288. { .compatible = "dallas,ds1340", .data = ds_1340 },
  289. { .compatible = "microchip,mcp7941x", .data = mcp794xx },
  290. { .compatible = "st,m41t11", .data = m41t11 },
  291. { }
  292. };
  293. U_BOOT_DRIVER(rtc_ds1307) = {
  294. .name = "rtc-ds1307",
  295. .id = UCLASS_RTC,
  296. .probe = ds1307_probe,
  297. .of_match = ds1307_rtc_ids,
  298. .ops = &ds1307_rtc_ops,
  299. };
  300. #endif /* CONFIG_DM_RTC */