minix/drivers/power/tps65950/rtc.c

   1 #include <minix/ds.h>
   2 #include <minix/drivers.h>
   3 #include <minix/i2c.h>
   4 #include <minix/i2cdriver.h>
   5 #include <minix/log.h>
   6
   7 #include <time.h>
   8
   9 #include "tps65950.h"
  10 #include "rtc.h"
  11
  12 /* logging - use with log_warn(), log_info(), log_debug(), log_trace(), etc */
  13 static struct log log = {
  14         .name = "tps65950.rtc",
  15         .log_level = LEVEL_INFO,
  16         .log_func = default_log
  17 };
  18
  19 static int bcd_to_dec(int n);
  20 static int dec_to_bcd(int n);
  21
  22 int
  23 rtc_init(void)
  24 {
  25         int r;
  26         uint8_t val;
  27         struct tm t;
  28
  29         r = i2creg_set_bits8(bus_endpoint, addresses[ID4], RTC_CTRL_REG,
  30             (1 << STOP_RTC_BIT));
  31         if (r != OK) {
  32                 log_warn(&log, "Failed to start RTC\n");
  33                 return -1;
  34         }
  35
  36         r = i2creg_read8(bus_endpoint, addresses[ID4], RTC_STATUS_REG, &val);
  37         if (r != OK) {
  38                 log_warn(&log, "Failed to read RTC_STATUS_REG\n");
  39                 return -1;
  40         }
  41
  42         if ((val & (1 << RUN_BIT)) != (1 << RUN_BIT)) {
  43                 log_warn(&log, "RTC did not start. Bad MSECURE?\n");
  44                 return -1;
  45         }
  46
  47         log_debug(&log, "RTC Started\n");
  48
  49         return OK;
  50 }
  51
  52 int
  53 rtc_get_time(struct tm *t, int flags)
  54 {
  55         int r;
  56         uint8_t val;
  57
  58         memset(t, '\0', sizeof(struct tm));
  59
  60         /* Write GET_TIME_BIT to RTC_CTRL_REG to latch the RTC values into
  61          * the RTC registers. This is required before each read.
  62          */
  63         r = i2creg_set_bits8(bus_endpoint, addresses[ID4], RTC_CTRL_REG,
  64             (1 << GET_TIME_BIT));
  65         if (r != OK) {
  66                 return -1;
  67         }
  68
  69         /* Read and Convert BCD to binary (default RTC mode). */
  70
  71         /* Seconds - 0 to 59 */
  72         r = i2creg_read8(bus_endpoint, addresses[ID4], SECONDS_REG, &val);
  73         if (r != OK) {
  74                 return -1;
  75         }
  76         t->tm_sec = bcd_to_dec(val & 0x7f);
  77
  78         /* Minutes - 0 to 59 */
  79         r = i2creg_read8(bus_endpoint, addresses[ID4], MINUTES_REG, &val);
  80         if (r != OK) {
  81                 return -1;
  82         }
  83         t->tm_min = bcd_to_dec(val & 0x7f);
  84
  85         /* Hours - 0 to 23 */
  86         r = i2creg_read8(bus_endpoint, addresses[ID4], HOURS_REG, &val);
  87         if (r != OK) {
  88                 return -1;
  89         }
  90         t->tm_hour = bcd_to_dec(val & 0x3f);
  91
  92         /* Days - 1 to 31 */
  93         r = i2creg_read8(bus_endpoint, addresses[ID4], DAYS_REG, &val);
  94         if (r != OK) {
  95                 return -1;
  96         }
  97         t->tm_mday = bcd_to_dec(val & 0x3f);
  98
  99         /* Months - Jan=1 to Dec=12 */
 100         r = i2creg_read8(bus_endpoint, addresses[ID4], MONTHS_REG, &val);
 101         if (r != OK) {
 102                 return -1;
 103         }
 104         t->tm_mon = bcd_to_dec(val & 0x1f) - 1;
 105
 106         /* Years - last 2 digits of year */
 107         r = i2creg_read8(bus_endpoint, addresses[ID4], YEARS_REG, &val);
 108         if (r != OK) {
 109                 return -1;
 110         }
 111         t->tm_year = bcd_to_dec(val & 0x1f) + 100;
 112
 113         if (t->tm_year == 100) {
 114                 /* Cold start - no date/time set - default to 2013-01-01 */
 115                 t->tm_sec = 0;
 116                 t->tm_min = 0;
 117                 t->tm_hour = 0;
 118                 t->tm_mday = 1;
 119                 t->tm_mon = 0;
 120                 t->tm_year = 113;
 121
 122                 rtc_set_time(t, RTCDEV_NOFLAGS);
 123         }
 124
 125         return OK;
 126 }
 127
 128 int
 129 rtc_set_time(struct tm *t, int flags)
 130 {
 131         int r;
 132
 133         /* Write the date/time to the RTC registers. */
 134         r = i2creg_write8(bus_endpoint, addresses[ID4], SECONDS_REG,
 135             (dec_to_bcd(t->tm_sec) & 0x7f));
 136         if (r != OK) {
 137                 return -1;
 138         }
 139
 140         r = i2creg_write8(bus_endpoint, addresses[ID4], MINUTES_REG,
 141             (dec_to_bcd(t->tm_min) & 0x7f));
 142         if (r != OK) {
 143                 return -1;
 144         }
 145
 146         r = i2creg_write8(bus_endpoint, addresses[ID4], HOURS_REG,
 147             (dec_to_bcd(t->tm_hour) & 0x3f));
 148         if (r != OK) {
 149                 return -1;
 150         }
 151
 152         r = i2creg_write8(bus_endpoint, addresses[ID4], DAYS_REG,
 153             (dec_to_bcd(t->tm_mday) & 0x3f));
 154         if (r != OK) {
 155                 return -1;
 156         }
 157
 158         r = i2creg_write8(bus_endpoint, addresses[ID4], MONTHS_REG,
 159             (dec_to_bcd(t->tm_mon + 1) & 0x1f));
 160         if (r != OK) {
 161                 return -1;
 162         }
 163
 164         r = i2creg_write8(bus_endpoint, addresses[ID4], YEARS_REG,
 165             (dec_to_bcd(t->tm_year % 100) & 0xff));
 166         if (r != OK) {
 167                 return -1;
 168         }
 169
 170         return OK;
 171 }
 172
 173 int
 174 rtc_exit(void)
 175 {
 176         return OK;
 177 }
 178
 179 static int
 180 bcd_to_dec(int n)
 181 {
 182         return ((n >> 4) & 0x0F) * 10 + (n & 0x0F);
 183 }
 184
 185 static int
 186 dec_to_bcd(int n)
 187 {
 188         return ((n / 10) << 4) | (n % 10);
 189 }