minix/drivers/tps65950/rtc.c
Thomas Cort 75bd3009d3 libi2cdriver: add functions for IC register access
Many i2c device drivers used similar code to access registers on
the ICs they drive. This commit implements that functionality in
libi2cdriver and updates the drivers to use the library instead of
their own register access functions. The net result is 375+ fewer
lines of code and less work for people developing new drivers.

The two exceptions were cat24c256 and parts of tda19988. They access
the bus in uncommon ways. It doesn't make sense at this time to
move their read/write functions into libi2cdriver.

Change-Id: Id8280b71af33b710a49944d7f20a7262be9f5988
2013-09-18 08:10:26 -04:00

189 lines
3.7 KiB
C

#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 = i2creg_set_bits8(bus_endpoint, addresses[ID4], RTC_CTRL_REG,
(1 << STOP_RTC_BIT));
if (r != OK) {
log_warn(&log, "Failed to start RTC\n");
return -1;
}
r = i2creg_read8(bus_endpoint, addresses[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 = i2creg_set_bits8(bus_endpoint, addresses[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 = i2creg_read8(bus_endpoint, addresses[ID4], SECONDS_REG, &val);
if (r != OK) {
return -1;
}
t->tm_sec = bcd_to_dec(val & 0x7f);
/* Minutes - 0 to 59 */
r = i2creg_read8(bus_endpoint, addresses[ID4], MINUTES_REG, &val);
if (r != OK) {
return -1;
}
t->tm_min = bcd_to_dec(val & 0x7f);
/* Hours - 0 to 23 */
r = i2creg_read8(bus_endpoint, addresses[ID4], HOURS_REG, &val);
if (r != OK) {
return -1;
}
t->tm_hour = bcd_to_dec(val & 0x3f);
/* Days - 1 to 31 */
r = i2creg_read8(bus_endpoint, addresses[ID4], DAYS_REG, &val);
if (r != OK) {
return -1;
}
t->tm_mday = bcd_to_dec(val & 0x3f);
/* Months - Jan=1 to Dec=12 */
r = i2creg_read8(bus_endpoint, addresses[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 = i2creg_read8(bus_endpoint, addresses[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 = i2creg_write8(bus_endpoint, addresses[ID4], SECONDS_REG,
(dec_to_bcd(t->tm_sec) & 0x7f));
if (r != OK) {
return -1;
}
r = i2creg_write8(bus_endpoint, addresses[ID4], MINUTES_REG,
(dec_to_bcd(t->tm_min) & 0x7f));
if (r != OK) {
return -1;
}
r = i2creg_write8(bus_endpoint, addresses[ID4], HOURS_REG,
(dec_to_bcd(t->tm_hour) & 0x3f));
if (r != OK) {
return -1;
}
r = i2creg_write8(bus_endpoint, addresses[ID4], DAYS_REG,
(dec_to_bcd(t->tm_mday) & 0x3f));
if (r != OK) {
return -1;
}
r = i2creg_write8(bus_endpoint, addresses[ID4], MONTHS_REG,
(dec_to_bcd(t->tm_mon + 1) & 0x1f));
if (r != OK) {
return -1;
}
r = i2creg_write8(bus_endpoint, addresses[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);
}