diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/rtc/rv3029.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/drivers/rtc/rv3029.c b/drivers/rtc/rv3029.c index 3ebc768..e012168 100644 --- a/drivers/rtc/rv3029.c +++ b/drivers/rtc/rv3029.c @@ -25,6 +25,12 @@ #include <i2c.h> #include <rtc.h> +#define RTC_RV3029_CTRL1 0x00 +#define RTC_RV3029_CTRL1_EERE (1 << 3) + +#define RTC_RV3029_CTRL_STATUS 0x03 +#define RTC_RV3029_CTRLS_EEBUSY (1 << 7) + #define RTC_RV3029_CTRL_RESET 0x04 #define RTC_RV3029_CTRL_SYS_R (1 << 4) @@ -42,6 +48,12 @@ #define RV3029C2_REG_HR_12_24 (1 << 6) /* 24h/12h mode */ #define RV3029C2_REG_HR_PM (1 << 5) /* PM/AM bit in 12h mode */ +#define RTC_RV3029_EEPROM_CTRL 0x30 +#define RTC_RV3029_TRICKLE_1K (1 << 4) +#define RTC_RV3029_TRICKLE_5K (1 << 5) +#define RTC_RV3029_TRICKLE_20K (1 << 6) +#define RTC_RV3029_TRICKLE_80K (1 << 7) + int rtc_get( struct rtc_time *tmp ) { int ret; @@ -113,6 +125,41 @@ int rtc_set( struct rtc_time *tmp ) return 0; } +/* sets EERE-Bit (automatic EEPROM refresh) */ +static void set_eere_bit(int state) +{ + int ret; + unsigned char reg_ctrl1; + + ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1, + ®_ctrl1, 1); + + if (state) + reg_ctrl1 |= RTC_RV3029_CTRL1_EERE; + else + reg_ctrl1 &= (~RTC_RV3029_CTRL1_EERE); + + ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL1, 1, + ®_ctrl1, 1); +} + +/* waits until EEPROM page is no longer busy (times out after 10ms*loops) */ +static int wait_eebusy(int loops) +{ + int i, ret; + unsigned char ctrl_status; + + for (i = 0; i < loops; i++) { + ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_STATUS, + 1, &ctrl_status, 1); + + if ((ctrl_status & RTC_RV3029_CTRLS_EEBUSY) == 0) + break; + udelay(10000); + } + return i; +} + void rtc_reset (void) { int ret; @@ -121,4 +168,44 @@ void rtc_reset (void) buf[0] = RTC_RV3029_CTRL_SYS_R; ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_CTRL_RESET, 1, buf, 1); + +#if defined(CONFIG_SYS_RV3029_TCR) + /* + * because EEPROM_CTRL register is in EEPROM page it is necessary to + * disable automatic EEPROM refresh and check if EEPROM is busy + * before EEPORM_CTRL register may be accessed + */ + set_eere_bit(0); + wait_eebusy(100); + /* read current trickle charger setting */ + ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, RTC_RV3029_EEPROM_CTRL, + 1, buf, 1); + /* enable automatic EEPROM refresh again */ + set_eere_bit(1); + + /* + * to minimize EEPROM access write trickle charger setting only if it + * differs from current value + */ + if ((buf[0] & 0xF0) != CONFIG_SYS_RV3029_TCR) { + buf[0] = (buf[0] & 0x0F) | CONFIG_SYS_RV3029_TCR; + /* + * write trickle charger setting (disable autom. EEPROM + * refresh and wait until EEPROM is idle) + */ + set_eere_bit(0); + wait_eebusy(100); + ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, + RTC_RV3029_EEPROM_CTRL, 1, buf, 1); + /* + * it is necessary to wait 10ms before EEBUSY-Bit may be read + * (this is not documented in the data sheet yet, but the + * manufacturer recommends it) + */ + udelay(10000); + /* wait until EEPROM write access is finished */ + wait_eebusy(100); + set_eere_bit(1); + } +#endif } |