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: David Jander <david@protonic.nl>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/da9052-i2c.c b/drivers/mfd/da9052-i2c.c
index 6a9fec4..c319c4e 100644
--- a/drivers/mfd/da9052-i2c.c
+++ b/drivers/mfd/da9052-i2c.c
@@ -86,7 +86,11 @@
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 @@
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 @@
return ret;
}
- ret = da9052_i2c_enable_multiwrite(da9052);
+ ret = da9052_i2c_disable_multiwrite(da9052);
if (ret < 0)
return ret;