Re: [PATCH v2 15/17] power: axp20x_battery: Add constant charge current table

Sebastian Reichel
2022-06-09T21:11:35Z

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Hi,

On Tue, Jun 07, 2022 at 04:53:22PM +0100, Aidan MacDonald wrote:
> Add a table-based lookup method for constant charge current,
> which is necessary when the setting cannot be represented as
> a linear range.
>
> Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
> ---
> drivers/power/supply/axp20x_battery.c | 53 +++++++++++++++++++++------
> 1 file changed, 41 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/power/supply/axp20x_battery.c b/drivers/power/supply/axp20x_battery.c
> index 9106077c0dbb..87fb958f2224 100644
> --- a/drivers/power/supply/axp20x_battery.c
> +++ b/drivers/power/supply/axp20x_battery.c
> @@ -61,6 +61,7 @@ struct axp20x_batt_ps;
> struct axp_data {
> int ccc_scale;
> int ccc_offset;
> + const int *ccc_table;

Please document the struct; especially the fact that ccc_table must
have a size of AXP20X_CHRG_CTRL1_TGT_CURR + 1.

-- Sebastian

> bool has_fg_valid;
> int (*get_max_voltage)(struct axp20x_batt_ps *batt, int *val);
> int (*set_max_voltage)(struct axp20x_batt_ps *batt, int val);
> @@ -176,7 +177,10 @@ static int axp20x_get_constant_charge_current(struct axp20x_batt_ps *axp,
>
> *val &= AXP20X_CHRG_CTRL1_TGT_CURR;
>
> - *val = *val * axp->data->ccc_scale + axp->data->ccc_offset;
> + if (axp->data->ccc_table)
> + *val = axp->data->ccc_table[*val];
> + else
> + *val = *val * axp->data->ccc_scale + axp->data->ccc_offset;
>
> return 0;
> }
> @@ -389,16 +393,36 @@ static int axp20x_battery_set_max_voltage(struct axp20x_batt_ps *axp20x_batt,
> AXP20X_CHRG_CTRL1_TGT_VOLT, val);
> }
>
> +static int axp20x_get_constant_charge_current_sel(struct axp20x_batt_ps *axp_batt,
> + int charge_current)
> +{
> + int i;
> +
> + if (axp_batt->data->ccc_table) {
> + for (i = AXP20X_CHRG_CTRL1_TGT_CURR; i >= 0; --i) {
> + if (axp_batt->data->ccc_table[i] <= charge_current)
> + return i;
> + }
> +
> + return -EINVAL;
> + }
> +
> + i = (charge_current - axp_batt->data->ccc_offset) / axp_batt->data->ccc_scale;
> +
> + if (i > AXP20X_CHRG_CTRL1_TGT_CURR || i < 0)
> + return -EINVAL;
> +
> + return i;
> +}
> +
> static int axp20x_set_constant_charge_current(struct axp20x_batt_ps *axp_batt,
> int charge_current)
> {
> if (charge_current > axp_batt->max_ccc)
> return -EINVAL;
>
> - charge_current = (charge_current - axp_batt->data->ccc_offset) /
> - axp_batt->data->ccc_scale;
> -
> - if (charge_current > AXP20X_CHRG_CTRL1_TGT_CURR || charge_current < 0)
> + charge_current = axp20x_get_constant_charge_current_sel(axp_batt, charge_current);
> + if (charge_current < 0)
> return -EINVAL;
>
> return regmap_update_bits(axp_batt->regmap, AXP20X_CHRG_CTRL1,
> @@ -410,14 +434,14 @@ static int axp20x_set_max_constant_charge_current(struct axp20x_batt_ps *axp,
> {
> bool lower_max = false;
>
> - charge_current = (charge_current - axp->data->ccc_offset) /
> - axp->data->ccc_scale;
> -
> - if (charge_current > AXP20X_CHRG_CTRL1_TGT_CURR || charge_current < 0)
> + charge_current = axp20x_get_constant_charge_current_sel(axp, charge_current);
> + if (charge_current < 0)
> return -EINVAL;
>
> - charge_current = charge_current * axp->data->ccc_scale +
> - axp->data->ccc_offset;
> + if (axp->data->ccc_table)
> + charge_current = axp->data->ccc_table[charge_current];
> + else
> + charge_current = charge_current * axp->data->ccc_scale + axp->data->ccc_offset;
>
> if (charge_current > axp->max_ccc)
> dev_warn(axp->dev,
> @@ -629,7 +653,12 @@ static int axp20x_power_probe(struct platform_device *pdev)
> ccc)) {
> dev_err(&pdev->dev,
> "couldn't set constant charge current from DT: fallback to minimum value\n");
> - ccc = 300000;
> +
> + if (axp20x_batt->data->ccc_table)
> + ccc = axp20x_batt->data->ccc_table[0];
> + else
> + ccc = axp20x_batt->data->ccc_offset;
> +
> axp20x_batt->max_ccc = ccc;
> axp20x_set_constant_charge_current(axp20x_batt, ccc);
> }
> --
> 2.35.1
>

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