Commit 43e30f23 authored by David Jander's avatar David Jander Committed by Lee Jones
Browse files

mfd: da9052: Avoid multiwrite mode due to silicon errata 



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: default avatarDavid Jander <david@protonic.nl>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent 61e6cfa8

drivers/mfd/da9052-i2c.c

+8 −4
Original line number Diff line number Diff line
@@ -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;

include/linux/mfd/da9052/da9052.h

+14 −6
Original line number Diff line number Diff line
@@ -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);

	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);

	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);