minix/drivers/tps65950/rtc.c

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#include <minix/ds.h>
#include <minix/drivers.h>
#include <minix/i2c.h>
#include <minix/i2cdriver.h>
#include <minix/log.h>
#include <time.h>
#include "tps65950.h"
#include "rtc.h"
/* logging - use with log_warn(), log_info(), log_debug(), log_trace(), etc */
static struct log log = {
.name = "tps65950.rtc",
.log_level = LEVEL_INFO,
.log_func = default_log
};
static int bcd_to_dec(int n);
static int dec_to_bcd(int n);
int
rtc_init(void)
{
int r;
uint8_t val;
struct tm t;
r = reg_set(ID4, RTC_CTRL_REG, (1 << STOP_RTC_BIT));
if (r != OK) {
log_warn(&log, "Failed to start RTC\n");
return -1;
}
r = reg_read(ID4, RTC_STATUS_REG, &val);
if (r != OK) {
log_warn(&log, "Failed to read RTC_STATUS_REG\n");
return -1;
}
if ((val & (1 << RUN_BIT)) != (1 << RUN_BIT)) {
log_warn(&log, "RTC did not start. Bad MSECURE?\n");
return -1;
}
log_debug(&log, "RTC Started\n");
return OK;
}
int
rtc_get_time(struct tm *t, int flags)
{
int r;
uint8_t val;
memset(t, '\0', sizeof(struct tm));
/* Write GET_TIME_BIT to RTC_CTRL_REG to latch the RTC values into
* the RTC registers. This is required before each read.
*/
r = reg_set(ID4, RTC_CTRL_REG, (1 << GET_TIME_BIT));
if (r != OK) {
return -1;
}
/* Read and Convert BCD to binary (default RTC mode). */
/* Seconds - 0 to 59 */
r = reg_read(ID4, SECONDS_REG, &val);
if (r != OK) {
return -1;
}
t->tm_sec = bcd_to_dec(val & 0x7f);
/* Minutes - 0 to 59 */
r = reg_read(ID4, MINUTES_REG, &val);
if (r != OK) {
return -1;
}
t->tm_min = bcd_to_dec(val & 0x7f);
/* Hours - 0 to 23 */
r = reg_read(ID4, HOURS_REG, &val);
if (r != OK) {
return -1;
}
t->tm_hour = bcd_to_dec(val & 0x3f);
/* Days - 1 to 31 */
r = reg_read(ID4, DAYS_REG, &val);
if (r != OK) {
return -1;
}
t->tm_mday = bcd_to_dec(val & 0x3f);
/* Months - Jan=1 to Dec=12 */
r = reg_read(ID4, MONTHS_REG, &val);
if (r != OK) {
return -1;
}
t->tm_mon = bcd_to_dec(val & 0x1f) - 1;
/* Years - last 2 digits of year */
r = reg_read(ID4, YEARS_REG, &val);
if (r != OK) {
return -1;
}
t->tm_year = bcd_to_dec(val & 0x1f) + 100;
if (t->tm_year == 100) {
/* Cold start - no date/time set - default to 2013-01-01 */
t->tm_sec = 0;
t->tm_min = 0;
t->tm_hour = 0;
t->tm_mday = 1;
t->tm_mon = 0;
t->tm_year = 113;
rtc_set_time(t, RTCDEV_NOFLAGS);
}
return OK;
}
int
rtc_set_time(struct tm *t, int flags)
{
int r;
/* Write the date/time to the RTC registers. */
r = reg_write(ID4, SECONDS_REG, (dec_to_bcd(t->tm_sec) & 0x7f));
if (r != OK) {
return -1;
}
r = reg_write(ID4, MINUTES_REG, (dec_to_bcd(t->tm_min) & 0x7f));
if (r != OK) {
return -1;
}
r = reg_write(ID4, HOURS_REG, (dec_to_bcd(t->tm_hour) & 0x3f));
if (r != OK) {
return -1;
}
r = reg_write(ID4, DAYS_REG, (dec_to_bcd(t->tm_mday) & 0x3f));
if (r != OK) {
return -1;
}
r = reg_write(ID4, MONTHS_REG, (dec_to_bcd(t->tm_mon + 1) & 0x1f));
if (r != OK) {
return -1;
}
r = reg_write(ID4, YEARS_REG, (dec_to_bcd(t->tm_year % 100) & 0xff));
if (r != OK) {
return -1;
}
return OK;
}
int
rtc_exit(void)
{
return OK;
}
static int
bcd_to_dec(int n)
{
return ((n >> 4) & 0x0F) * 10 + (n & 0x0F);
}
static int
dec_to_bcd(int n)
{
return ((n / 10) << 4) | (n % 10);
}