[PATCH v3 00/11] Add support for the TI BQ25792 battery charger

[PATCH v3 00/11] Add support for the TI BQ25792 battery charger

[Alexey Charkov]

This adds support for the TI BQ25792 battery charger, which is similar in
overall logic to the BQ25703A, but has a different register layout and
slightly different lower-level programming logic.

The series is organized as follows:
- Patch 1 adds the new variant to the existing DT binding, including the
  changes in electrical characteristics
- Patches 2-4 are minor cleanups to the existing BQ25703A OTG regulator
  driver, slimming down the code and making it more reusable for the new
  BQ25792 variant
- Patch 5 is a logical fix to the BQ25703A clamping logic for VSYSMIN
  (this is a standalone fix which can be applied independently and may be
  backported to stable)
- Patches 6-8 are slight refactoring of the existing BQ25703A charger
  driver to make it more reusable for the new BQ25792 variant
- Patch 9 adds platform data to distinguish between the two variants in
  the parent MFD driver, and binds it to the new compatible string
- Patches 10-11 add variant-specific code to support the new BQ25792
  variant in the regulator part and the charger part respectively,
  selected by the platform data added in patch 9

Signed-off-by: Alexey Charkov <alchark@flipper.net>
---
Changes in v3:
- Move MFD cell definitions back out of the probe function (Lee Jones)
- Collect tags from Mark Brown, Krzysztof Kozlowski and Chris Morgan (thanks!)
- Enable ship FET functionality at init for BQ25792
- Link to v2: https://lore.kernel.org/r/20260306-bq25792-v2-0-6595249d6e6f@flipper.net

Changes in v2:
- Fix an error in DT schema (thanks Rob's bot)
- Ensure the broadest constraints for all variants remain in the common
  part of the schema, per writing-schema doc (thanks Krzysztof)
- Link to v1: https://lore.kernel.org/r/20260303-bq25792-v1-0-e6e5e0033458@flipper.net

---
Alexey Charkov (11):
      dt-bindings: mfd: ti,bq25703a: Expand to include BQ25792
      regulator: bq257xx: Remove reference to the parent MFD's dev
      regulator: bq257xx: Drop the regulator_dev from the driver data
      regulator: bq257xx: Make OTG enable GPIO really optional
      power: supply: bq257xx: Fix VSYSMIN clamping logic
      power: supply: bq257xx: Make the default current limit a per-chip attribute
      power: supply: bq257xx: Consistently use indirect get/set helpers
      power: supply: bq257xx: Add fields for 'charging' and 'overvoltage' states
      mfd: bq257xx: Add BQ25792 support
      regulator: bq257xx: Add support for BQ25792
      power: supply: bq257xx: Add support for BQ25792

 .../devicetree/bindings/mfd/ti,bq25703a.yaml       |  73 ++-
 drivers/mfd/bq257xx.c                              |  64 ++-
 drivers/power/supply/bq257xx_charger.c             | 535 ++++++++++++++++++++-
 drivers/regulator/bq257xx-regulator.c              | 123 ++++-
 include/linux/mfd/bq257xx.h                        | 415 ++++++++++++++++
 5 files changed, 1170 insertions(+), 40 deletions(-)
---
base-commit: a0ae2a256046c0c5d3778d1a194ff2e171f16e5f
change-id: 20260303-bq25792-0132ac86846d

Best regards,
-- 
Alexey Charkov <alchark@flipper.net>

[PATCH v3 05/11] power: supply: bq257xx: Fix VSYSMIN clamping logic

[Alexey Charkov]

The minimal system voltage (VSYSMIN) is meant to protect the battery from
dangerous over-discharge. When the device tree provides a value for the
minimum design voltage of the battery, the user should not be allowed to
set a lower VSYSMIN, as that would defeat the purpose of this protection.

Flip the clamping logic when setting VSYSMIN to ensure that battery design
voltage is respected.

Cc: stable@vger.kernel.org
Fixes: 1cc017b7f9c7 ("power: supply: bq257xx: Add support for BQ257XX charger")
Tested-by: Chris Morgan <macromorgan@hotmail.com>
Signed-off-by: Alexey Charkov <alchark@flipper.net>
---
 drivers/power/supply/bq257xx_charger.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/power/supply/bq257xx_charger.c b/drivers/power/supply/bq257xx_charger.c
index 02c7d8b61e82..7ca4ae610902 100644
--- a/drivers/power/supply/bq257xx_charger.c
+++ b/drivers/power/supply/bq257xx_charger.c
@@ -128,9 +128,8 @@ static int bq25703_get_min_vsys(struct bq257xx_chg *pdata, int *intval)
  * @vsys: voltage value to set in uV.
  *
  * This function takes a requested minimum system voltage value, clamps
- * it between the minimum supported value by the charger and a user
- * defined minimum system value, and then writes the value to the
- * appropriate register.
+ * it between the user defined minimum system value and the maximum supported
+ * value by the charger, and then writes the value to the appropriate register.
  *
  * Return: Returns 0 on success or error if an error occurs.
  */
@@ -139,7 +138,7 @@ static int bq25703_set_min_vsys(struct bq257xx_chg *pdata, int vsys)
 	unsigned int reg;
 	int vsys_min = pdata->vsys_min;
 
-	vsys = clamp(vsys, BQ25703_MINVSYS_MIN_UV, vsys_min);
+	vsys = clamp(vsys, vsys_min, BQ25703_MINVSYS_MAX_UV);
 	reg = ((vsys - BQ25703_MINVSYS_MIN_UV) / BQ25703_MINVSYS_STEP_UV);
 	reg = FIELD_PREP(BQ25703_MINVSYS_MASK, reg);
 

-- 
2.52.0

Re: [PATCH v3 05/11] power: supply: bq257xx: Fix VSYSMIN clamping logic

[Sebastian Reichel]

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Hi,

On Tue, Mar 10, 2026 at 01:28:29PM +0400, Alexey Charkov wrote:
> The minimal system voltage (VSYSMIN) is meant to protect the battery from
> dangerous over-discharge. When the device tree provides a value for the
> minimum design voltage of the battery, the user should not be allowed to
> set a lower VSYSMIN, as that would defeat the purpose of this protection.
> 
> Flip the clamping logic when setting VSYSMIN to ensure that battery design
> voltage is respected.
> 
> Cc: stable@vger.kernel.org
> Fixes: 1cc017b7f9c7 ("power: supply: bq257xx: Add support for BQ257XX charger")
> Tested-by: Chris Morgan <macromorgan@hotmail.com>
> Signed-off-by: Alexey Charkov <alchark@flipper.net>
> ---

Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>

-- Sebastian

>  drivers/power/supply/bq257xx_charger.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/power/supply/bq257xx_charger.c b/drivers/power/supply/bq257xx_charger.c
> index 02c7d8b61e82..7ca4ae610902 100644
> --- a/drivers/power/supply/bq257xx_charger.c
> +++ b/drivers/power/supply/bq257xx_charger.c
> @@ -128,9 +128,8 @@ static int bq25703_get_min_vsys(struct bq257xx_chg *pdata, int *intval)
>   * @vsys: voltage value to set in uV.
>   *
>   * This function takes a requested minimum system voltage value, clamps
> - * it between the minimum supported value by the charger and a user
> - * defined minimum system value, and then writes the value to the
> - * appropriate register.
> + * it between the user defined minimum system value and the maximum supported
> + * value by the charger, and then writes the value to the appropriate register.
>   *
>   * Return: Returns 0 on success or error if an error occurs.
>   */
> @@ -139,7 +138,7 @@ static int bq25703_set_min_vsys(struct bq257xx_chg *pdata, int vsys)
>  	unsigned int reg;
>  	int vsys_min = pdata->vsys_min;
>  
> -	vsys = clamp(vsys, BQ25703_MINVSYS_MIN_UV, vsys_min);
> +	vsys = clamp(vsys, vsys_min, BQ25703_MINVSYS_MAX_UV);
>  	reg = ((vsys - BQ25703_MINVSYS_MIN_UV) / BQ25703_MINVSYS_STEP_UV);
>  	reg = FIELD_PREP(BQ25703_MINVSYS_MASK, reg);
>  
> 
> -- 
> 2.52.0
> 
> 

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