Re: [PATCH RFC 06/11] power: supply: max77693: Set charge current limits during init

Krzysztof Kozlowski
2024-05-31T09:47:53Z

On 30/05/2024 10:55, Artur Weber wrote:
> There are two charger current limit registers:
>
> - Fast charge current limit (which controls current going from the
> charger to the battery);
> - CHGIN input current limit (which controls current going into the
> charger through the cable, and is managed by the CHARGER regulator).
>
> Add functions for setting both of the values, and set them to a
> safe default value of 500mA at initialization.
>
> The default value for the fast charge current limit can be modified
> by setting the maxim,fast-charge-current-microamp DT property; the
> CHGIN input current limit will be set up later in the charger detection
> mechanism.
>
> Signed-off-by: Artur Weber <aweber.kernel@gmail.com>
> ---
> drivers/power/supply/max77693_charger.c | 45 +++++++++++++++++++++++++++++++++
> 1 file changed, 45 insertions(+)
>
> diff --git a/drivers/power/supply/max77693_charger.c b/drivers/power/supply/max77693_charger.c
> index 894c35b750b3..d59b1524b0a4 100644
> --- a/drivers/power/supply/max77693_charger.c
> +++ b/drivers/power/supply/max77693_charger.c
> @@ -28,6 +28,7 @@ struct max77693_charger {
> u32 min_system_volt;
> u32 thermal_regulation_temp;
> u32 batttery_overcurrent;
> + u32 fast_charge_current;
> u32 charge_input_threshold_volt;
> };
>
> @@ -591,6 +592,35 @@ static int max77693_set_batttery_overcurrent(struct max77693_charger *chg,
> CHG_CNFG_12_B2SOVRC_MASK, data);
> }
>
> +static int max77693_set_input_current_limit(struct max77693_charger *chg,
> + unsigned int uamp)
> +{
> + dev_dbg(chg->dev, "CHGIN input current limit: %u\n", uamp);

That's quite useless debug. It duplicates
max77693_set_fast_charge_current(). Just drop entire wrapper.

> +
> + return regulator_set_current_limit(chg->regu, (int)uamp, (int)uamp);
> +}
> +
> +static int max77693_set_fast_charge_current(struct max77693_charger *chg,
> + unsigned int uamp)
> +{
> + unsigned int data;
> +
> + data = (uamp / 1000) * 10 / 333; /* 0.1A/3 steps */
> +
> + if (data > CHG_CNFG_02_CC_MASK) {
> + dev_err(chg->dev, "Wrong value for fast charge current\n");
> + return -EINVAL;
> + }
> +
> + data <<= CHG_CNFG_02_CC_SHIFT;
> +
> + dev_dbg(chg->dev, "Fast charge current: %u (0x%x)\n", uamp, data);
> +
> + return regmap_update_bits(chg->max77693->regmap,
> + MAX77693_CHG_REG_CHG_CNFG_02,
> + CHG_CNFG_02_CC_MASK, data);

I am surprised that you set current limit via regulator but actual
charging current value here. I think both should go to regulator in such
case.
>

Best regards,
Krzysztof