[PATCH] mfd: bq257xx: Mark self-modifying BQ25792 registers volatile
From: Alexey Charkov
Date: Thu Oct 01 2026 - 09:58:26 EST
Some BQ25792 configuration registers change without being written: input
source detection sets VINDPM and IINDPM at plug-in, plug-in also clears
EN_HIZ, the FORCE_* bits clear once their operation starts or completes,
EN_ACDRV1/2 follow input path changes, and ADC_EN clears after a one-shot
conversion. Reading them from the cache returns stale values.
Mark these registers volatile, keeping the cache for the rest.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 9adbe53e32cd ("mfd: bq257xx: Add BQ25792 support")
Signed-off-by: Alexey Charkov <alchark@xxxxxxxxxxx>
---
drivers/mfd/bq257xx.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/mfd/bq257xx.c b/drivers/mfd/bq257xx.c
index 054342c60b73..01f5fc97f538 100644
--- a/drivers/mfd/bq257xx.c
+++ b/drivers/mfd/bq257xx.c
@@ -52,8 +52,18 @@ static const struct regmap_access_table bq25792_writeable_regs = {
};
static const struct regmap_range bq25792_volatile_reg_ranges[] = {
+ regmap_reg_range(BQ25792_REG05_INPUT_VOLTAGE_LIMIT,
+ BQ25792_REG06_INPUT_CURRENT_LIMIT + 1),
+ regmap_reg_range(BQ25792_REG0F_CHARGER_CONTROL_0,
+ BQ25792_REG0F_CHARGER_CONTROL_0),
+ regmap_reg_range(BQ25792_REG11_CHARGER_CONTROL_2,
+ BQ25792_REG11_CHARGER_CONTROL_2),
+ regmap_reg_range(BQ25792_REG13_CHARGER_CONTROL_4,
+ BQ25792_REG13_CHARGER_CONTROL_4),
regmap_reg_range(BQ25792_REG19_ICO_CURRENT_LIMIT,
BQ25792_REG27_FAULT_FLAG_1),
+ regmap_reg_range(BQ25792_REG2E_ADC_CONTROL,
+ BQ25792_REG2E_ADC_CONTROL),
regmap_reg_range(BQ25792_REG31_IBUS_ADC,
BQ25792_REG47_DPDM_DRIVER),
};
---
base-commit: 6c2cb8b8b843d216ab549b678a0d8831c43153e0
change-id: 20261001-bq25792-volatile-2dc583517c1c
Best regards,
--
Alexey Charkov <alchark@xxxxxxxxxxx>