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rtc, rv3029: add trickle charger support.

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Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
This commit is contained in:
Heiko Schocher 2011-03-28 09:24:22 +02:00 committed by Wolfgang Denk
parent 31e413985c
commit 71d19f30d6
2 changed files with 89 additions and 0 deletions
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2
README
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@ -748,6 +748,8 @@ The following options need to be configured:
CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
CONFIG_SYS_RV3029_TCR - enable trickle charger on
RV3029 RTC.
Note that if the RTC uses I2C, then the I2C interface
must also be configured. See I2C Support, below.

87
drivers/rtc/rv3029.c
View file

@ -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,
&reg_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,
&reg_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
}