ds1306.c 13 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * (C) Copyright 2002 SIXNET, dge@sixnetio.com.
  4. *
  5. * (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
  6. * Stephan Linz <linz@li-pro.net>
  7. */
  8. /*
  9. * Date & Time support for DS1306 RTC using SPI:
  10. *
  11. * - SXNI855T: it uses its own soft SPI here in this file
  12. * - all other: use the external spi_xfer() function
  13. * (see include/spi.h)
  14. */
  15. #include <common.h>
  16. #include <command.h>
  17. #include <rtc.h>
  18. #include <spi.h>
  19. #include <linux/delay.h>
  20. #define RTC_SECONDS 0x00
  21. #define RTC_MINUTES 0x01
  22. #define RTC_HOURS 0x02
  23. #define RTC_DAY_OF_WEEK 0x03
  24. #define RTC_DATE_OF_MONTH 0x04
  25. #define RTC_MONTH 0x05
  26. #define RTC_YEAR 0x06
  27. #define RTC_SECONDS_ALARM0 0x07
  28. #define RTC_MINUTES_ALARM0 0x08
  29. #define RTC_HOURS_ALARM0 0x09
  30. #define RTC_DAY_OF_WEEK_ALARM0 0x0a
  31. #define RTC_SECONDS_ALARM1 0x0b
  32. #define RTC_MINUTES_ALARM1 0x0c
  33. #define RTC_HOURS_ALARM1 0x0d
  34. #define RTC_DAY_OF_WEEK_ALARM1 0x0e
  35. #define RTC_CONTROL 0x0f
  36. #define RTC_STATUS 0x10
  37. #define RTC_TRICKLE_CHARGER 0x11
  38. #define RTC_USER_RAM_BASE 0x20
  39. /* ************************************************************************* */
  40. #ifdef CONFIG_SXNI855T /* !!! SHOULD BE CHANGED TO NEW CODE !!! */
  41. static void soft_spi_send (unsigned char n);
  42. static unsigned char soft_spi_read (void);
  43. static void init_spi (void);
  44. /*-----------------------------------------------------------------------
  45. * Definitions
  46. */
  47. #define PB_SPISCK 0x00000002 /* PB 30 */
  48. #define PB_SPIMOSI 0x00000004 /* PB 29 */
  49. #define PB_SPIMISO 0x00000008 /* PB 28 */
  50. #define PB_SPI_CE 0x00010000 /* PB 15 */
  51. /* ------------------------------------------------------------------------- */
  52. /* read clock time from DS1306 and return it in *tmp */
  53. int rtc_get (struct rtc_time *tmp)
  54. {
  55. volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  56. unsigned char spi_byte; /* Data Byte */
  57. init_spi (); /* set port B for software SPI */
  58. /* Now we can enable the DS1306 RTC */
  59. immap->im_cpm.cp_pbdat |= PB_SPI_CE;
  60. udelay(10);
  61. /* Shift out the address (0) of the time in the Clock Chip */
  62. soft_spi_send (0);
  63. /* Put the clock readings into the rtc_time structure */
  64. tmp->tm_sec = bcd2bin (soft_spi_read ()); /* Read seconds */
  65. tmp->tm_min = bcd2bin (soft_spi_read ()); /* Read minutes */
  66. /* Hours are trickier */
  67. spi_byte = soft_spi_read (); /* Read Hours into temporary value */
  68. if (spi_byte & 0x40) {
  69. /* 12 hour mode bit is set (time is in 1-12 format) */
  70. if (spi_byte & 0x20) {
  71. /* since PM we add 11 to get 0-23 for hours */
  72. tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) + 11;
  73. } else {
  74. /* since AM we subtract 1 to get 0-23 for hours */
  75. tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) - 1;
  76. }
  77. } else {
  78. /* Otherwise, 0-23 hour format */
  79. tmp->tm_hour = (bcd2bin (spi_byte & 0x3F));
  80. }
  81. soft_spi_read (); /* Read and discard Day of week */
  82. tmp->tm_mday = bcd2bin (soft_spi_read ()); /* Read Day of the Month */
  83. tmp->tm_mon = bcd2bin (soft_spi_read ()); /* Read Month */
  84. /* Read Year and convert to this century */
  85. tmp->tm_year = bcd2bin (soft_spi_read ()) + 2000;
  86. /* Now we can disable the DS1306 RTC */
  87. immap->im_cpm.cp_pbdat &= ~PB_SPI_CE; /* Disable DS1306 Chip */
  88. udelay(10);
  89. rtc_calc_weekday(tmp); /* Determine the day of week */
  90. debug ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  91. tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  92. tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  93. return 0;
  94. }
  95. /* ------------------------------------------------------------------------- */
  96. /* set clock time in DS1306 RTC and in MPC8xx RTC */
  97. int rtc_set (struct rtc_time *tmp)
  98. {
  99. volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  100. init_spi (); /* set port B for software SPI */
  101. /* Now we can enable the DS1306 RTC */
  102. immap->im_cpm.cp_pbdat |= PB_SPI_CE; /* Enable DS1306 Chip */
  103. udelay(10);
  104. /* First disable write protect in the clock chip control register */
  105. soft_spi_send (0x8F); /* send address of the control register */
  106. soft_spi_send (0x00); /* send control register contents */
  107. /* Now disable the DS1306 to terminate the write */
  108. immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;
  109. udelay(10);
  110. /* Now enable the DS1306 to initiate a new write */
  111. immap->im_cpm.cp_pbdat |= PB_SPI_CE;
  112. udelay(10);
  113. /* Next, send the address of the clock time write registers */
  114. soft_spi_send (0x80); /* send address of the first time register */
  115. /* Use Burst Mode to send all of the time data to the clock */
  116. bin2bcd (tmp->tm_sec);
  117. soft_spi_send (bin2bcd (tmp->tm_sec)); /* Send Seconds */
  118. soft_spi_send (bin2bcd (tmp->tm_min)); /* Send Minutes */
  119. soft_spi_send (bin2bcd (tmp->tm_hour)); /* Send Hour */
  120. soft_spi_send (bin2bcd (tmp->tm_wday)); /* Send Day of the Week */
  121. soft_spi_send (bin2bcd (tmp->tm_mday)); /* Send Day of Month */
  122. soft_spi_send (bin2bcd (tmp->tm_mon)); /* Send Month */
  123. soft_spi_send (bin2bcd (tmp->tm_year - 2000)); /* Send Year */
  124. /* Now we can disable the Clock chip to terminate the burst write */
  125. immap->im_cpm.cp_pbdat &= ~PB_SPI_CE; /* Disable DS1306 Chip */
  126. udelay(10);
  127. /* Now we can enable the Clock chip to initiate a new write */
  128. immap->im_cpm.cp_pbdat |= PB_SPI_CE; /* Enable DS1306 Chip */
  129. udelay(10);
  130. /* First we Enable write protect in the clock chip control register */
  131. soft_spi_send (0x8F); /* send address of the control register */
  132. soft_spi_send (0x40); /* send out Control Register contents */
  133. /* Now disable the DS1306 */
  134. immap->im_cpm.cp_pbdat &= ~PB_SPI_CE; /* Disable DS1306 Chip */
  135. udelay(10);
  136. /* Set standard MPC8xx clock to the same time so Linux will
  137. * see the time even if it doesn't have a DS1306 clock driver.
  138. * This helps with experimenting with standard kernels.
  139. */
  140. {
  141. ulong tim;
  142. tim = rtc_mktime(tmp);
  143. immap->im_sitk.sitk_rtck = KAPWR_KEY;
  144. immap->im_sit.sit_rtc = tim;
  145. }
  146. debug ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  147. tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  148. tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  149. return 0;
  150. }
  151. /* ------------------------------------------------------------------------- */
  152. /* Initialize Port B for software SPI */
  153. static void init_spi (void)
  154. {
  155. volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  156. /* Force output pins to begin at logic 0 */
  157. immap->im_cpm.cp_pbdat &= ~(PB_SPI_CE | PB_SPIMOSI | PB_SPISCK);
  158. /* Set these 3 signals as outputs */
  159. immap->im_cpm.cp_pbdir |= (PB_SPIMOSI | PB_SPI_CE | PB_SPISCK);
  160. immap->im_cpm.cp_pbdir &= ~PB_SPIMISO; /* Make MISO pin an input */
  161. udelay(10);
  162. }
  163. /* ------------------------------------------------------------------------- */
  164. /* NOTE: soft_spi_send() assumes that the I/O lines are configured already */
  165. static void soft_spi_send (unsigned char n)
  166. {
  167. volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  168. unsigned char bitpos; /* bit position to receive */
  169. unsigned char i; /* Loop Control */
  170. /* bit position to send, start with most significant bit */
  171. bitpos = 0x80;
  172. /* Send 8 bits to software SPI */
  173. for (i = 0; i < 8; i++) { /* Loop for 8 bits */
  174. immap->im_cpm.cp_pbdat |= PB_SPISCK; /* Raise SCK */
  175. if (n & bitpos)
  176. immap->im_cpm.cp_pbdat |= PB_SPIMOSI; /* Set MOSI to 1 */
  177. else
  178. immap->im_cpm.cp_pbdat &= ~PB_SPIMOSI; /* Set MOSI to 0 */
  179. udelay(10);
  180. immap->im_cpm.cp_pbdat &= ~PB_SPISCK; /* Lower SCK */
  181. udelay(10);
  182. bitpos >>= 1; /* Shift for next bit position */
  183. }
  184. }
  185. /* ------------------------------------------------------------------------- */
  186. /* NOTE: soft_spi_read() assumes that the I/O lines are configured already */
  187. static unsigned char soft_spi_read (void)
  188. {
  189. volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  190. unsigned char spi_byte = 0; /* Return value, assume success */
  191. unsigned char bitpos; /* bit position to receive */
  192. unsigned char i; /* Loop Control */
  193. /* bit position to receive, start with most significant bit */
  194. bitpos = 0x80;
  195. /* Read 8 bits here */
  196. for (i = 0; i < 8; i++) { /* Do 8 bits in loop */
  197. immap->im_cpm.cp_pbdat |= PB_SPISCK; /* Raise SCK */
  198. udelay(10);
  199. if (immap->im_cpm.cp_pbdat & PB_SPIMISO) /* Get a bit of data */
  200. spi_byte |= bitpos; /* Set data accordingly */
  201. immap->im_cpm.cp_pbdat &= ~PB_SPISCK; /* Lower SCK */
  202. udelay(10);
  203. bitpos >>= 1; /* Shift for next bit position */
  204. }
  205. return spi_byte; /* Return the byte read */
  206. }
  207. /* ------------------------------------------------------------------------- */
  208. void rtc_reset (void)
  209. {
  210. return; /* nothing to do */
  211. }
  212. #else /* not CONFIG_SXNI855T */
  213. /* ************************************************************************* */
  214. static unsigned char rtc_read (unsigned char reg);
  215. static void rtc_write (unsigned char reg, unsigned char val);
  216. static struct spi_slave *slave;
  217. /* read clock time from DS1306 and return it in *tmp */
  218. int rtc_get (struct rtc_time *tmp)
  219. {
  220. unsigned char sec, min, hour, mday, wday, mon, year;
  221. /*
  222. * Assuming Vcc = 2.0V (lowest speed)
  223. *
  224. * REVISIT: If we add an rtc_init() function we can do this
  225. * step just once.
  226. */
  227. if (!slave) {
  228. slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
  229. SPI_MODE_3 | SPI_CS_HIGH);
  230. if (!slave)
  231. return;
  232. }
  233. if (spi_claim_bus(slave))
  234. return;
  235. sec = rtc_read (RTC_SECONDS);
  236. min = rtc_read (RTC_MINUTES);
  237. hour = rtc_read (RTC_HOURS);
  238. mday = rtc_read (RTC_DATE_OF_MONTH);
  239. wday = rtc_read (RTC_DAY_OF_WEEK);
  240. mon = rtc_read (RTC_MONTH);
  241. year = rtc_read (RTC_YEAR);
  242. spi_release_bus(slave);
  243. debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
  244. "hr: %02x min: %02x sec: %02x\n",
  245. year, mon, mday, wday, hour, min, sec);
  246. debug ("Alarms[0]: wday: %02x hour: %02x min: %02x sec: %02x\n",
  247. rtc_read (RTC_DAY_OF_WEEK_ALARM0),
  248. rtc_read (RTC_HOURS_ALARM0),
  249. rtc_read (RTC_MINUTES_ALARM0), rtc_read (RTC_SECONDS_ALARM0));
  250. debug ("Alarms[1]: wday: %02x hour: %02x min: %02x sec: %02x\n",
  251. rtc_read (RTC_DAY_OF_WEEK_ALARM1),
  252. rtc_read (RTC_HOURS_ALARM1),
  253. rtc_read (RTC_MINUTES_ALARM1), rtc_read (RTC_SECONDS_ALARM1));
  254. tmp->tm_sec = bcd2bin (sec & 0x7F); /* convert Seconds */
  255. tmp->tm_min = bcd2bin (min & 0x7F); /* convert Minutes */
  256. /* convert Hours */
  257. tmp->tm_hour = (hour & 0x40)
  258. ? ((hour & 0x20) /* 12 hour mode */
  259. ? bcd2bin (hour & 0x1F) + 11 /* PM */
  260. : bcd2bin (hour & 0x1F) - 1 /* AM */
  261. )
  262. : bcd2bin (hour & 0x3F); /* 24 hour mode */
  263. tmp->tm_mday = bcd2bin (mday & 0x3F); /* convert Day of the Month */
  264. tmp->tm_mon = bcd2bin (mon & 0x1F); /* convert Month */
  265. tmp->tm_year = bcd2bin (year) + 2000; /* convert Year */
  266. tmp->tm_wday = bcd2bin (wday & 0x07) - 1; /* convert Day of the Week */
  267. tmp->tm_yday = 0;
  268. tmp->tm_isdst = 0;
  269. debug ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  270. tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  271. tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  272. return 0;
  273. }
  274. /* ------------------------------------------------------------------------- */
  275. /* set clock time from *tmp in DS1306 RTC */
  276. int rtc_set (struct rtc_time *tmp)
  277. {
  278. /* Assuming Vcc = 2.0V (lowest speed) */
  279. if (!slave) {
  280. slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
  281. SPI_MODE_3 | SPI_CS_HIGH);
  282. if (!slave)
  283. return;
  284. }
  285. if (spi_claim_bus(slave))
  286. return;
  287. debug ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  288. tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
  289. tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  290. rtc_write (RTC_SECONDS, bin2bcd (tmp->tm_sec));
  291. rtc_write (RTC_MINUTES, bin2bcd (tmp->tm_min));
  292. rtc_write (RTC_HOURS, bin2bcd (tmp->tm_hour));
  293. rtc_write (RTC_DAY_OF_WEEK, bin2bcd (tmp->tm_wday + 1));
  294. rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday));
  295. rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon));
  296. rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000));
  297. spi_release_bus(slave);
  298. }
  299. /* ------------------------------------------------------------------------- */
  300. /* reset the DS1306 */
  301. void rtc_reset (void)
  302. {
  303. /* Assuming Vcc = 2.0V (lowest speed) */
  304. if (!slave) {
  305. slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
  306. SPI_MODE_3 | SPI_CS_HIGH);
  307. if (!slave)
  308. return;
  309. }
  310. if (spi_claim_bus(slave))
  311. return;
  312. /* clear the control register */
  313. rtc_write (RTC_CONTROL, 0x00); /* 1st step: reset WP */
  314. rtc_write (RTC_CONTROL, 0x00); /* 2nd step: reset 1Hz, AIE1, AIE0 */
  315. /* reset all alarms */
  316. rtc_write (RTC_SECONDS_ALARM0, 0x00);
  317. rtc_write (RTC_SECONDS_ALARM1, 0x00);
  318. rtc_write (RTC_MINUTES_ALARM0, 0x00);
  319. rtc_write (RTC_MINUTES_ALARM1, 0x00);
  320. rtc_write (RTC_HOURS_ALARM0, 0x00);
  321. rtc_write (RTC_HOURS_ALARM1, 0x00);
  322. rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00);
  323. rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00);
  324. spi_release_bus(slave);
  325. }
  326. /* ------------------------------------------------------------------------- */
  327. static unsigned char rtc_read (unsigned char reg)
  328. {
  329. int ret;
  330. ret = spi_w8r8(slave, reg);
  331. return ret < 0 ? 0 : ret;
  332. }
  333. /* ------------------------------------------------------------------------- */
  334. static void rtc_write (unsigned char reg, unsigned char val)
  335. {
  336. unsigned char dout[2]; /* SPI Output Data Bytes */
  337. unsigned char din[2]; /* SPI Input Data Bytes */
  338. dout[0] = 0x80 | reg;
  339. dout[1] = val;
  340. spi_xfer (slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
  341. }
  342. #endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */