Re: [PATCH 3/7] regulator: sy7636a: add VCOM voltage control

[Andreas Kemnade <andreas@kemnade.info>]

On Mon, 26 Oct 2026 00:39:14 +0000
Pablo Mazzini <pmazzini@gmail.com> wrote:

> VCOM is panel specific, so let boards set it in the devicetree. Switch
> to the selector ops and add the write side.
> 
> Per the datasheet, VCOM bit 8 is bit 7 of register 0x02, not bit 0.
> 
> Signed-off-by: Pablo Mazzini <pmazzini@gmail.com>

Reviewed-by: Andreas Kemnade <andreas@kemnade.info>
> ---
>  drivers/regulator/sy7636a-regulator.c | 31 +++++++++++++++++++++++----
>  1 file changed, 27 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/regulator/sy7636a-regulator.c b/drivers/regulator/sy7636a-regulator.c
> index 015227cb113e..382bab017784 100644
> --- a/drivers/regulator/sy7636a-regulator.c
> +++ b/drivers/regulator/sy7636a-regulator.c
> @@ -24,7 +24,7 @@ struct sy7636a_data {
>  	struct gpio_desc *vcom_en_gpio;
>  };
>  
> -static int sy7636a_get_vcom_voltage_op(struct regulator_dev *rdev)
> +static int sy7636a_get_vcom_voltage_sel(struct regulator_dev *rdev)
>  {
>  	int ret;
>  	unsigned int val, val_h;
> @@ -37,9 +37,20 @@ static int sy7636a_get_vcom_voltage_op(struct regulator_dev *rdev)
>  	if (ret)
>  		return ret;
>  
> -	val |= (val_h << VCOM_ADJUST_CTRL_SHIFT);
> +	/* VCOM[8] is bit 7 of register 0x02 */
> +	return val | (val_h & BIT(7)) << 1;
> +}
>  
> -	return (val & VCOM_ADJUST_CTRL_MASK) * VCOM_ADJUST_CTRL_SCAL;
> +static int sy7636a_set_vcom_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
> +{
> +	int ret;
> +
> +	ret = regmap_write(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_L, sel & 0xff);
> +	if (ret)
> +		return ret;
> +
> +	return regmap_update_bits(rdev->regmap, SY7636A_REG_VCOM_ADJUST_CTRL_H, BIT(7),
> +				  (sel & BIT(8)) >> 1);
>  }
>  
>  static int sy7636a_get_status(struct regulator_dev *rdev)
> @@ -55,19 +66,31 @@ static int sy7636a_get_status(struct regulator_dev *rdev)
>  }
>  
>  static const struct regulator_ops sy7636a_vcom_volt_ops = {
> -	.get_voltage = sy7636a_get_vcom_voltage_op,
> +	.list_voltage = regulator_list_voltage_linear_range,
> +	.map_voltage = regulator_map_voltage_linear_range,
> +	.get_voltage_sel = sy7636a_get_vcom_voltage_sel,
> +	.set_voltage_sel = sy7636a_set_vcom_voltage_sel,
>  	.enable = regulator_enable_regmap,
>  	.disable = regulator_disable_regmap,
>  	.is_enabled = regulator_is_enabled_regmap,
>  	.get_status = sy7636a_get_status,
>  };
>  
> +/* 10 mV steps up to 5 V, higher codes also give 5 V */
> +static const struct linear_range sy7636a_vcom_ranges[] = {
> +	REGULATOR_LINEAR_RANGE(0, 0x000, 0x1f4, VCOM_ADJUST_CTRL_SCAL),
> +	REGULATOR_LINEAR_RANGE(5000000, 0x1f5, 0x1ff, 0),
> +};
> +
>  static const struct regulator_desc desc = {
>  	.name = "vcom",
>  	.id = 0,
>  	.ops = &sy7636a_vcom_volt_ops,
>  	.type = REGULATOR_VOLTAGE,
>  	.owner = THIS_MODULE,
> +	.n_voltages = VCOM_ADJUST_CTRL_MASK + 1,
> +	.linear_ranges = sy7636a_vcom_ranges,
> +	.n_linear_ranges = ARRAY_SIZE(sy7636a_vcom_ranges),
>  	.enable_reg = SY7636A_REG_OPERATION_MODE_CRL,
>  	.enable_mask = SY7636A_OPERATION_MODE_CRL_ONOFF,
>  	.regulators_node = of_match_ptr("regulators"),