ds1307.c 8.8 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 <rtc.h>
  18. #include <i2c.h>
  19. enum ds_type {
  20. ds_1307,
  21. ds_1337,
  22. ds_1340,
  23. mcp794xx,
  24. };
  25. /*
  26. * RTC register addresses
  27. */
  28. #define RTC_SEC_REG_ADDR 0x00
  29. #define RTC_MIN_REG_ADDR 0x01
  30. #define RTC_HR_REG_ADDR 0x02
  31. #define RTC_DAY_REG_ADDR 0x03
  32. #define RTC_DATE_REG_ADDR 0x04
  33. #define RTC_MON_REG_ADDR 0x05
  34. #define RTC_YR_REG_ADDR 0x06
  35. #define RTC_CTL_REG_ADDR 0x07
  36. #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
  37. #define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */
  38. #define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */
  39. #define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */
  40. #define RTC_CTL_BIT_OUT 0x80 /* Output Control */
  41. /* MCP7941X-specific bits */
  42. #define MCP7941X_BIT_ST 0x80
  43. #define MCP7941X_BIT_VBATEN 0x08
  44. #ifndef CONFIG_DM_RTC
  45. /*---------------------------------------------------------------------*/
  46. #undef DEBUG_RTC
  47. #ifdef DEBUG_RTC
  48. #define DEBUGR(fmt, args...) printf(fmt, ##args)
  49. #else
  50. #define DEBUGR(fmt, args...)
  51. #endif
  52. /*---------------------------------------------------------------------*/
  53. #ifndef CONFIG_SYS_I2C_RTC_ADDR
  54. # define CONFIG_SYS_I2C_RTC_ADDR 0x68
  55. #endif
  56. #if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
  57. # error The DS1307 is specified only up to 100kHz!
  58. #endif
  59. static uchar rtc_read (uchar reg);
  60. static void rtc_write (uchar reg, uchar val);
  61. /*
  62. * Get the current time from the RTC
  63. */
  64. int rtc_get (struct rtc_time *tmp)
  65. {
  66. int rel = 0;
  67. uchar sec, min, hour, mday, wday, mon, year;
  68. #ifdef CONFIG_RTC_MCP79411
  69. read_rtc:
  70. #endif
  71. sec = rtc_read (RTC_SEC_REG_ADDR);
  72. min = rtc_read (RTC_MIN_REG_ADDR);
  73. hour = rtc_read (RTC_HR_REG_ADDR);
  74. wday = rtc_read (RTC_DAY_REG_ADDR);
  75. mday = rtc_read (RTC_DATE_REG_ADDR);
  76. mon = rtc_read (RTC_MON_REG_ADDR);
  77. year = rtc_read (RTC_YR_REG_ADDR);
  78. DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
  79. "hr: %02x min: %02x sec: %02x\n",
  80. year, mon, mday, wday, hour, min, sec);
  81. #ifdef CONFIG_RTC_DS1307
  82. if (sec & RTC_SEC_BIT_CH) {
  83. printf ("### Warning: RTC oscillator has stopped\n");
  84. /* clear the CH flag */
  85. rtc_write (RTC_SEC_REG_ADDR,
  86. rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH);
  87. rel = -1;
  88. }
  89. #endif
  90. #ifdef CONFIG_RTC_MCP79411
  91. /* make sure that the backup battery is enabled */
  92. if (!(wday & MCP7941X_BIT_VBATEN)) {
  93. rtc_write(RTC_DAY_REG_ADDR,
  94. wday | MCP7941X_BIT_VBATEN);
  95. }
  96. /* clock halted? turn it on, so clock can tick. */
  97. if (!(sec & MCP7941X_BIT_ST)) {
  98. rtc_write(RTC_SEC_REG_ADDR, MCP7941X_BIT_ST);
  99. printf("Started RTC\n");
  100. goto read_rtc;
  101. }
  102. #endif
  103. tmp->tm_sec = bcd2bin (sec & 0x7F);
  104. tmp->tm_min = bcd2bin (min & 0x7F);
  105. tmp->tm_hour = bcd2bin (hour & 0x3F);
  106. tmp->tm_mday = bcd2bin (mday & 0x3F);
  107. tmp->tm_mon = bcd2bin (mon & 0x1F);
  108. tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
  109. tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
  110. tmp->tm_yday = 0;
  111. tmp->tm_isdst= 0;
  112. DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  113. tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  114. tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  115. return rel;
  116. }
  117. /*
  118. * Set the RTC
  119. */
  120. int rtc_set (struct rtc_time *tmp)
  121. {
  122. DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  123. tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  124. tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  125. if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
  126. printf("WARNING: year should be between 1970 and 2069!\n");
  127. rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
  128. rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
  129. #ifdef CONFIG_RTC_MCP79411
  130. rtc_write (RTC_DAY_REG_ADDR,
  131. bin2bcd (tmp->tm_wday + 1) | MCP7941X_BIT_VBATEN);
  132. #else
  133. rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
  134. #endif
  135. rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
  136. rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
  137. rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
  138. #ifdef CONFIG_RTC_MCP79411
  139. rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec) | MCP7941X_BIT_ST);
  140. #else
  141. rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
  142. #endif
  143. return 0;
  144. }
  145. /*
  146. * Reset the RTC. We setting the date back to 1970-01-01.
  147. * We also enable the oscillator output on the SQW/OUT pin and program
  148. * it for 32,768 Hz output. Note that according to the datasheet, turning
  149. * on the square wave output increases the current drain on the backup
  150. * battery to something between 480nA and 800nA.
  151. */
  152. void rtc_reset (void)
  153. {
  154. rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
  155. rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0);
  156. }
  157. /*
  158. * Helper functions
  159. */
  160. static
  161. uchar rtc_read (uchar reg)
  162. {
  163. return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
  164. }
  165. static void rtc_write (uchar reg, uchar val)
  166. {
  167. i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
  168. }
  169. #endif /* !CONFIG_DM_RTC */
  170. #ifdef CONFIG_DM_RTC
  171. static int ds1307_rtc_set(struct udevice *dev, const struct rtc_time *tm)
  172. {
  173. int ret;
  174. uchar buf[7];
  175. enum ds_type type = dev_get_driver_data(dev);
  176. debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  177. tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
  178. tm->tm_hour, tm->tm_min, tm->tm_sec);
  179. if (tm->tm_year < 1970 || tm->tm_year > 2069)
  180. printf("WARNING: year should be between 1970 and 2069!\n");
  181. buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
  182. buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
  183. buf[RTC_DAY_REG_ADDR] = bin2bcd(tm->tm_wday + 1);
  184. buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
  185. buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
  186. buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
  187. buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
  188. if (type == mcp794xx) {
  189. buf[RTC_DAY_REG_ADDR] |= MCP7941X_BIT_VBATEN;
  190. buf[RTC_SEC_REG_ADDR] |= MCP7941X_BIT_ST;
  191. }
  192. ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
  193. if (ret < 0)
  194. return ret;
  195. return 0;
  196. }
  197. static int ds1307_rtc_get(struct udevice *dev, struct rtc_time *tm)
  198. {
  199. int ret;
  200. uchar buf[7];
  201. enum ds_type type = dev_get_driver_data(dev);
  202. read_rtc:
  203. ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
  204. if (ret < 0)
  205. return ret;
  206. if (type == ds_1307) {
  207. if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) {
  208. printf("### Warning: RTC oscillator has stopped\n");
  209. /* clear the CH flag */
  210. buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH;
  211. dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
  212. buf[RTC_SEC_REG_ADDR]);
  213. return -1;
  214. }
  215. }
  216. if (type == mcp794xx) {
  217. /* make sure that the backup battery is enabled */
  218. if (!(buf[RTC_DAY_REG_ADDR] & MCP7941X_BIT_VBATEN)) {
  219. dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR,
  220. buf[RTC_DAY_REG_ADDR] |
  221. MCP7941X_BIT_VBATEN);
  222. }
  223. /* clock halted? turn it on, so clock can tick. */
  224. if (!(buf[RTC_SEC_REG_ADDR] & MCP7941X_BIT_ST)) {
  225. dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
  226. MCP7941X_BIT_ST);
  227. printf("Started RTC\n");
  228. goto read_rtc;
  229. }
  230. }
  231. tm->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
  232. tm->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
  233. tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
  234. tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
  235. tm->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
  236. tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) +
  237. (bcd2bin(buf[RTC_YR_REG_ADDR]) >= 70 ?
  238. 1900 : 2000);
  239. tm->tm_wday = bcd2bin((buf[RTC_DAY_REG_ADDR] - 1) & 0x07);
  240. tm->tm_yday = 0;
  241. tm->tm_isdst = 0;
  242. debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  243. tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
  244. tm->tm_hour, tm->tm_min, tm->tm_sec);
  245. return 0;
  246. }
  247. static int ds1307_rtc_reset(struct udevice *dev)
  248. {
  249. int ret;
  250. /* clear Clock Halt */
  251. ret = dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, 0x00);
  252. if (ret < 0)
  253. return ret;
  254. ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR,
  255. RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 |
  256. RTC_CTL_BIT_RS0);
  257. if (ret < 0)
  258. return ret;
  259. return 0;
  260. }
  261. static int ds1307_probe(struct udevice *dev)
  262. {
  263. i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
  264. DM_I2C_CHIP_WR_ADDRESS);
  265. return 0;
  266. }
  267. static const struct rtc_ops ds1307_rtc_ops = {
  268. .get = ds1307_rtc_get,
  269. .set = ds1307_rtc_set,
  270. .reset = ds1307_rtc_reset,
  271. };
  272. static const struct udevice_id ds1307_rtc_ids[] = {
  273. { .compatible = "dallas,ds1307", .data = ds_1307 },
  274. { .compatible = "dallas,ds1337", .data = ds_1337 },
  275. { .compatible = "dallas,ds1340", .data = ds_1340 },
  276. { .compatible = "microchip,mcp7941x", .data = mcp794xx },
  277. { }
  278. };
  279. U_BOOT_DRIVER(rtc_ds1307) = {
  280. .name = "rtc-ds1307",
  281. .id = UCLASS_RTC,
  282. .probe = ds1307_probe,
  283. .of_match = ds1307_rtc_ids,
  284. .ops = &ds1307_rtc_ops,
  285. };
  286. #endif /* CONFIG_DM_RTC */