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mfd: da9052: Avoid multiwrite mode due to silicon errata

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DA9053 (up to revision bc) can corrupt internal registers when multi-write
mode is enabled and power is removed or during shutdown.

Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
David Jander 2013-09-02 09:46:11 +02:00 committed by Lee Jones
parent 61e6cfa80d
commit 43e30f23b5
2 changed files with 22 additions and 10 deletions
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12
drivers/mfd/da9052-i2c.c
View file

@ -86,7 +86,11 @@ static int da9052_i2c_fix(struct da9052 *da9052, unsigned char reg)
return 0;
}
static int da9052_i2c_enable_multiwrite(struct da9052 *da9052)
/*
* According to errata item 24, multiwrite mode should be avoided
* in order to prevent register data corruption after power-down.
*/
static int da9052_i2c_disable_multiwrite(struct da9052 *da9052)
{
int reg_val, ret;
@ -94,8 +98,8 @@ static int da9052_i2c_enable_multiwrite(struct da9052 *da9052)
if (ret < 0)
return ret;
if (reg_val & DA9052_CONTROL_B_WRITEMODE) {
reg_val &= ~DA9052_CONTROL_B_WRITEMODE;
if (!(reg_val & DA9052_CONTROL_B_WRITEMODE)) {
reg_val |= DA9052_CONTROL_B_WRITEMODE;
ret = regmap_write(da9052->regmap, DA9052_CONTROL_B_REG,
reg_val);
if (ret < 0)
@ -154,7 +158,7 @@ static int da9052_i2c_probe(struct i2c_client *client,
return ret;
}
ret = da9052_i2c_enable_multiwrite(da9052);
ret = da9052_i2c_disable_multiwrite(da9052);
if (ret < 0)
return ret;

20
include/linux/mfd/da9052/da9052.h
View file

@ -148,10 +148,15 @@ static inline int da9052_group_read(struct da9052 *da9052, unsigned char reg,
unsigned reg_cnt, unsigned char *val)
{
int ret;
unsigned int tmp;
int i;
ret = regmap_bulk_read(da9052->regmap, reg, val, reg_cnt);
if (ret < 0)
return ret;
for (i = 0; i < reg_cnt; i++) {
ret = regmap_read(da9052->regmap, reg + i, &tmp);
val[i] = (unsigned char)tmp;
if (ret < 0)
return ret;
}
if (da9052->fix_io) {
ret = da9052->fix_io(da9052, reg);
@ -166,10 +171,13 @@ static inline int da9052_group_write(struct da9052 *da9052, unsigned char reg,
unsigned reg_cnt, unsigned char *val)
{
int ret;
int i;
ret = regmap_raw_write(da9052->regmap, reg, val, reg_cnt);
if (ret < 0)
return ret;
for (i = 0; i < reg_cnt; i++) {
ret = regmap_write(da9052->regmap, reg + i, val[i]);
if (ret < 0)
return ret;
}
if (da9052->fix_io) {
ret = da9052->fix_io(da9052, reg);