[v4,14/15] power: axp20x_battery: Support battery status without fuel gauge

Add a "has_fg" flag to indicate that the chip has a fuel gauge.
Report battery full status on chips with no fuel gauge using the
battery voltage.

Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
---
 drivers/power/supply/axp20x_battery.c | 34 ++++++++++++++++++++++++++-
 1 file changed, 33 insertions(+), 1 deletion(-)

On Wed, Jun 29, 2022 at 4:30 PM Aidan MacDonald
<aidanmacdonald.0x0@gmail.com> wrote:
>
> Add a "has_fg" flag to indicate that the chip has a fuel gauge.
> Report battery full status on chips with no fuel gauge using the
> battery voltage.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
> ---
>  drivers/power/supply/axp20x_battery.c | 34 ++++++++++++++++++++++++++-
>  1 file changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/power/supply/axp20x_battery.c b/drivers/power/supply/axp20x_battery.c
> index 401779d84d2b..574c1d001556 100644
> --- a/drivers/power/supply/axp20x_battery.c
> +++ b/drivers/power/supply/axp20x_battery.c
> @@ -69,6 +69,7 @@ struct axp_data {
>          * must have AXP20X_CHRG_CTRL1_TGT_CURR+1 elements.
>          */
>         const int *ccc_table;
> +       bool    has_fg;
>         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);
> @@ -197,7 +198,7 @@ static int axp20x_battery_get_prop(struct power_supply *psy,
>                                    union power_supply_propval *val)
>  {
>         struct axp20x_batt_ps *axp20x_batt = power_supply_get_drvdata(psy);
> -       int ret = 0, reg, val1;
> +       int ret = 0, reg, val1, val2;
>
>         switch (psp) {
>         case POWER_SUPPLY_PROP_PRESENT:
> @@ -231,6 +232,34 @@ static int axp20x_battery_get_prop(struct power_supply *psy,
>                         return 0;
>                 }
>
> +               /*
> +                * If the chip does not have a fuel gauge, we check battery full status
> +                * using voltage instead.
> +                */
> +               if (!axp20x_batt->data->has_fg) {
> +                       ret = axp20x_batt->data->get_max_voltage(axp20x_batt, &val1);
> +                       if (ret)
> +                               return ret;
> +
> +                       ret = iio_read_channel_processed(axp20x_batt->batt_v, &val2);
> +                       if (ret)
> +                               return ret;
> +
> +                       /* IIO subsystem reports voltage in mV but we need uV */
> +                       val2 *= 1000;
> +
> +                       /*
> +                        * According to the AXP192 datasheet, charging will restart if
> +                        * the battery voltage drops below V_rch = V_tgt - 0.1 V, so we
> +                        * report the battery is full if its voltage is at least V_rch.
> +                        */
> +                       if (val2 >= val1 - 100000)
> +                               val->intval = POWER_SUPPLY_STATUS_FULL;
> +                       else
> +                               val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
> +                       break;
> +               }
> +
>                 ret = regmap_read(axp20x_batt->regmap, AXP20X_FG_RES, &val1);
>                 if (ret)
>                         return ret;
> @@ -552,6 +581,7 @@ static const struct power_supply_desc axp20x_batt_ps_desc = {
>  static const struct axp_data axp209_data = {
>         .ccc_scale = 100000,
>         .ccc_offset = 300000,
> +       .has_fg = true,
>         .get_max_voltage = axp20x_battery_get_max_voltage,
>         .set_max_voltage = axp20x_battery_set_max_voltage,
>  };
> @@ -559,6 +589,7 @@ static const struct axp_data axp209_data = {
>  static const struct axp_data axp221_data = {
>         .ccc_scale = 150000,
>         .ccc_offset = 300000,
> +       .has_fg = true,
>         .has_fg_valid = true,
>         .get_max_voltage = axp22x_battery_get_max_voltage,
>         .set_max_voltage = axp22x_battery_set_max_voltage,
> @@ -567,6 +598,7 @@ static const struct axp_data axp221_data = {
>  static const struct axp_data axp813_data = {
>         .ccc_scale = 200000,
>         .ccc_offset = 200000,
> +       .has_fg = true,
>         .has_fg_valid = true,
>         .get_max_voltage = axp813_battery_get_max_voltage,
>         .set_max_voltage = axp20x_battery_set_max_voltage,
> --
> 2.35.1
>