linux-kernel - Re: [PATCH 5/8] power: supply: axp20x

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Date:   Sun, 10 Dec 2017 16:49:10 +0000
From:   Jonathan Cameron <jic23@...nel.org>
To:     Quentin Schulz <quentin.schulz@...e-electrons.com>
Cc:     sre@...nel.org, robh+dt@...nel.org, mark.rutland@....com,
        wens@...e.org, linux@...linux.org.uk,
        maxime.ripard@...e-electrons.com, lee.jones@...aro.org,
        knaack.h@....de, lars@...afoo.de, pmeerw@...erw.net,
        linux-pm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-iio@...r.kernel.org, icenowy@...c.io,
        linux-sunxi@...glegroups.com, thomas.petazzoni@...e-electrons.com
Subject: Re: [PATCH 5/8] power: supply: axp20x_battery: add support for
 AXP813

On Mon,  4 Dec 2017 15:12:51 +0100
Quentin Schulz <quentin.schulz@...e-electrons.com> wrote:

> The X-Powers AXP813 PMIC has got some slight differences from
> AXP20X/AXP22X PMICs:
>  - the maximum voltage supplied by the PMIC is 4.35 instead of 4.36/4.24
>  for AXP20X/AXP22X,
>  - the constant charge current formula is different,
> 
> It also has a bit to tell whether the battery percentage returned by the
> PMIC is valid.
> 
> Signed-off-by: Quentin Schulz <quentin.schulz@...e-electrons.com>

I'd use switch statements when matching the IDs as that'll be more elegant
as you perhaps add further devices going forward...

Other than that, looks good to me.

Jonathan

> ---
>  drivers/power/supply/axp20x_battery.c | 44 +++++++++++++++++++++++++++-
>  1 file changed, 43 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/power/supply/axp20x_battery.c b/drivers/power/supply/axp20x_battery.c
> index 7494f0f..cb30302 100644
> --- a/drivers/power/supply/axp20x_battery.c
> +++ b/drivers/power/supply/axp20x_battery.c
> @@ -46,6 +46,8 @@
>  #define AXP20X_CHRG_CTRL1_TGT_4_2V	(2 << 5)
>  #define AXP20X_CHRG_CTRL1_TGT_4_36V	(3 << 5)
>  
> +#define AXP813_CHRG_CTRL1_TGT_4_35V	(3 << 5)
> +
>  #define AXP22X_CHRG_CTRL1_TGT_4_22V	(1 << 5)
>  #define AXP22X_CHRG_CTRL1_TGT_4_24V	(3 << 5)
>  
> @@ -123,10 +125,41 @@ static int axp22x_battery_get_max_voltage(struct axp20x_batt_ps *axp20x_batt,
>  	return 0;
>  }
>  
> +static int axp813_battery_get_max_voltage(struct axp20x_batt_ps *axp20x_batt,
> +					  int *val)
> +{
> +	int ret, reg;
> +
> +	ret = regmap_read(axp20x_batt->regmap, AXP20X_CHRG_CTRL1, &reg);
> +	if (ret)
> +		return ret;
> +
> +	switch (reg & AXP20X_CHRG_CTRL1_TGT_VOLT) {

You could do a lookup based from a table instead which might
be ever so slightly more elegant..

> +	case AXP20X_CHRG_CTRL1_TGT_4_1V:
> +		*val = 4100000;
> +		break;
> +	case AXP20X_CHRG_CTRL1_TGT_4_15V:
> +		*val = 4150000;
> +		break;
> +	case AXP20X_CHRG_CTRL1_TGT_4_2V:
> +		*val = 4200000;
> +		break;
> +	case AXP813_CHRG_CTRL1_TGT_4_35V:
> +		*val = 4350000;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  static void raw_to_constant_charge_current(struct axp20x_batt_ps *axp, int *val)
>  {
>  	if (axp->axp_id == AXP209_ID)
>  		*val = *val * 100000 + 300000;
> +	else if (axp->axp_id == AXP813_ID)
> +		*val = *val * 200000 + 200000;
>  	else
>  		*val = *val * 150000 + 300000;

Switch?

>  }
> @@ -135,6 +168,8 @@ static void constant_charge_current_to_raw(struct axp20x_batt_ps *axp, int *val)
>  {
>  	if (axp->axp_id == AXP209_ID)
>  		*val = (*val - 300000) / 100000;
> +	else if (axp->axp_id == AXP813_ID)
> +		*val = (*val - 200000) / 200000;
>  	else
>  		*val = (*val - 300000) / 150000;
>  }
> @@ -269,7 +304,8 @@ static int axp20x_battery_get_prop(struct power_supply *psy,
>  		if (ret)
>  			return ret;
>  
> -		if (axp20x_batt->axp_id == AXP221_ID &&
> +		if ((axp20x_batt->axp_id == AXP221_ID ||
> +		     axp20x_batt->axp_id == AXP813_ID) &&
>  		    !(reg & AXP22X_FG_VALID))
>  			return -EINVAL;
>  
> @@ -284,6 +320,9 @@ static int axp20x_battery_get_prop(struct power_supply *psy,
>  		if (axp20x_batt->axp_id == AXP209_ID)
>  			return axp20x_battery_get_max_voltage(axp20x_batt,
>  							      &val->intval);
> +		else if (axp20x_batt->axp_id == AXP813_ID)
> +			return axp813_battery_get_max_voltage(axp20x_batt,
> +							      &val->intval);
>  		return axp22x_battery_get_max_voltage(axp20x_batt,
>  						      &val->intval);

Worth converting to a switch statement to make it more elegant for future
devices?

>  
> @@ -467,6 +506,9 @@ static const struct of_device_id axp20x_battery_ps_id[] = {
>  	}, {
>  		.compatible = "x-powers,axp221-battery-power-supply",
>  		.data = (void *)AXP221_ID,
> +	}, {
> +		.compatible = "x-powers,axp813-battery-power-supply",
> +		.data = (void *)AXP813_ID,
>  	}, { /* sentinel */ },
>  };
>  MODULE_DEVICE_TABLE(of, axp20x_battery_ps_id);