pcf2127.c 2.9 KB

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  1. /*
  2. * Copyright (C) 2016 by NXP Semiconductors Inc.
  3. * Date & Time support for PCF2127 RTC
  4. */
  5. /* #define DEBUG */
  6. #include <common.h>
  7. #include <command.h>
  8. #include <dm.h>
  9. #include <i2c.h>
  10. #include <rtc.h>
  11. #define PCF2127_REG_CTRL1 0x00
  12. #define PCF2127_REG_CTRL2 0x01
  13. #define PCF2127_REG_CTRL3 0x02
  14. #define PCF2127_REG_SC 0x03
  15. #define PCF2127_REG_MN 0x04
  16. #define PCF2127_REG_HR 0x05
  17. #define PCF2127_REG_DM 0x06
  18. #define PCF2127_REG_DW 0x07
  19. #define PCF2127_REG_MO 0x08
  20. #define PCF2127_REG_YR 0x09
  21. static int pcf2127_read_reg(struct udevice *dev, uint offset,
  22. u8 *buffer, int len)
  23. {
  24. struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
  25. struct i2c_msg msg;
  26. int ret;
  27. /* Set the address of the start register to be read */
  28. ret = dm_i2c_write(dev, offset, NULL, 0);
  29. if (ret < 0)
  30. return ret;
  31. /* Read register's data */
  32. msg.addr = chip->chip_addr;
  33. msg.flags |= I2C_M_RD;
  34. msg.len = len;
  35. msg.buf = buffer;
  36. return dm_i2c_xfer(dev, &msg, 1);
  37. }
  38. static int pcf2127_rtc_set(struct udevice *dev, const struct rtc_time *tm)
  39. {
  40. uchar buf[7] = {0};
  41. int i = 0, ret;
  42. /* hours, minutes and seconds */
  43. buf[i++] = bin2bcd(tm->tm_sec);
  44. buf[i++] = bin2bcd(tm->tm_min);
  45. buf[i++] = bin2bcd(tm->tm_hour);
  46. buf[i++] = bin2bcd(tm->tm_mday);
  47. buf[i++] = tm->tm_wday & 0x07;
  48. /* month, 1 - 12 */
  49. buf[i++] = bin2bcd(tm->tm_mon);
  50. /* year */
  51. buf[i++] = bin2bcd(tm->tm_year % 100);
  52. /* write register's data */
  53. ret = dm_i2c_write(dev, PCF2127_REG_SC, buf, i);
  54. return ret;
  55. }
  56. static int pcf2127_rtc_get(struct udevice *dev, struct rtc_time *tm)
  57. {
  58. int ret = 0;
  59. uchar buf[10] = { PCF2127_REG_CTRL1 };
  60. ret = pcf2127_read_reg(dev, PCF2127_REG_CTRL1, buf, sizeof(buf));
  61. if (ret < 0)
  62. return ret;
  63. if (buf[PCF2127_REG_CTRL3] & 0x04)
  64. puts("### Warning: RTC Low Voltage - date/time not reliable\n");
  65. tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
  66. tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
  67. tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F);
  68. tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
  69. tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F);
  70. tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]) + 1900;
  71. if (tm->tm_year < 1970)
  72. tm->tm_year += 100; /* assume we are in 1970...2069 */
  73. tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
  74. tm->tm_yday = 0;
  75. tm->tm_isdst = 0;
  76. debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
  77. tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
  78. tm->tm_hour, tm->tm_min, tm->tm_sec);
  79. return ret;
  80. }
  81. static int pcf2127_rtc_reset(struct udevice *dev)
  82. {
  83. /*Doing nothing here*/
  84. return 0;
  85. }
  86. static const struct rtc_ops pcf2127_rtc_ops = {
  87. .get = pcf2127_rtc_get,
  88. .set = pcf2127_rtc_set,
  89. .reset = pcf2127_rtc_reset,
  90. };
  91. static const struct udevice_id pcf2127_rtc_ids[] = {
  92. { .compatible = "pcf2127-rtc" },
  93. { }
  94. };
  95. U_BOOT_DRIVER(rtc_pcf2127) = {
  96. .name = "rtc-pcf2127",
  97. .id = UCLASS_RTC,
  98. .of_match = pcf2127_rtc_ids,
  99. .ops = &pcf2127_rtc_ops,
  100. };