Re: [08/15] power: supply: bq24190_charger: Add support for external fuel gauge

Liam Breck
2017-03-18T07:11:30Z

On Fri, 17 Mar 2017 10:55:20 +0100, Hans de Goede wrote:

> Some platforms with a bq24190_charger have an external fuel gauge which
> makes it possible to reliably report battery (dis)charge state, at
> support for this by adding an optional get_ext_bat_property callback
> to the platform_data and using this if the platform provides it.

Please do not pollute the charger with fuel-gauge functionality; use the gauge driver directly.

And calling into a mystery module with a pointer from platform-data is scary! St. Patrick's
Day is wrong for this; try April Fool's or Halloween ;-)

> By convention the callback will return -ENXIO when it is not ready yet,
> or the driver providing it has been unbound from its device. Since it
> returns the same error when unbound it cannot return -EPROBE_DEFER
> as that is not a valid errno.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> drivers/power/supply/bq24190_charger.c | 41 +++++++++++++++++++++++++++++++---
> include/linux/power/bq24190_charger.h | 4 ++++
> 2 files changed, 42 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/power/supply/bq24190_charger.c b/drivers/power/supply/bq24190_charger.c
> index 9014dee..9fe69a5 100644
> --- a/drivers/power/supply/bq24190_charger.c
> +++ b/drivers/power/supply/bq24190_charger.c
> @@ -1111,7 +1111,10 @@ static int bq24190_battery_get_property(struct power_supply *psy,
> ret = 0;
> break;
> default:
> - ret = -ENODATA;
> + if (bdi->pdata && bdi->pdata->get_ext_bat_property)
> + ret = bdi->pdata->get_ext_bat_property(psp, val);
> + else
> + ret = -ENODATA;
> }
>
> pm_runtime_put_sync(bdi->dev);
> @@ -1168,12 +1171,31 @@ static enum power_supply_property bq24190_battery_properties[] = {
> POWER_SUPPLY_PROP_TECHNOLOGY,
> POWER_SUPPLY_PROP_TEMP_ALERT_MAX,
> POWER_SUPPLY_PROP_SCOPE,
> + /* Begin of extended battery properties */
> + POWER_SUPPLY_PROP_VOLTAGE_NOW,
> + POWER_SUPPLY_PROP_VOLTAGE_AVG,
> + POWER_SUPPLY_PROP_VOLTAGE_OCV,
> + POWER_SUPPLY_PROP_CURRENT_NOW,
> + POWER_SUPPLY_PROP_CURRENT_AVG,
> + POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
> + POWER_SUPPLY_PROP_CHARGE_FULL,
> + POWER_SUPPLY_PROP_CHARGE_NOW,
> };
>
> static const struct power_supply_desc bq24190_battery_desc = {
> .name = "bq24190-battery",
> .type = POWER_SUPPLY_TYPE_BATTERY,
> .properties = bq24190_battery_properties,
> + .num_properties = 6,
> + .get_property = bq24190_battery_get_property,
> + .set_property = bq24190_battery_set_property,
> + .property_is_writeable = bq24190_battery_property_is_writeable,
> +};
> +
> +static const struct power_supply_desc bq24190_ext_battery_desc = {
> + .name = "bq24190-battery",
> + .type = POWER_SUPPLY_TYPE_BATTERY,
> + .properties = bq24190_battery_properties,
> .num_properties = ARRAY_SIZE(bq24190_battery_properties),
> .get_property = bq24190_battery_get_property,
> .set_property = bq24190_battery_set_property,
> @@ -1336,6 +1358,15 @@ static int bq24190_probe(struct i2c_client *client,
> return -EINVAL;
> }
>
> + if (bdi->pdata && bdi->pdata->get_ext_bat_property) {
> + union power_supply_propval val;
> +
> + /* Check external fuel gauge is ready */
> + ret = bdi->pdata->get_ext_bat_property(0, &val);
> + if (ret == -ENXIO)
> + return -EPROBE_DEFER;
> + }
> +
> pm_runtime_enable(dev);
> pm_runtime_resume(dev);
>
> @@ -1357,8 +1388,12 @@ static int bq24190_probe(struct i2c_client *client,
> }
>
> battery_cfg.drv_data = bdi;
> - bdi->battery = power_supply_register(dev, &bq24190_battery_desc,
> - &battery_cfg);
> + if (bdi->pdata && bdi->pdata->get_ext_bat_property)
> + bdi->battery = power_supply_register(dev,
> + &bq24190_ext_battery_desc, &battery_cfg);
> + else
> + bdi->battery = power_supply_register(dev,
> + &bq24190_battery_desc, &battery_cfg);
> if (IS_ERR(bdi->battery)) {
> dev_err(dev, "Can't register battery\n");
> ret = PTR_ERR(bdi->battery);
> diff --git a/include/linux/power/bq24190_charger.h b/include/linux/power/bq24190_charger.h
> index 8d918cb..02d248b 100644
> --- a/include/linux/power/bq24190_charger.h
> +++ b/include/linux/power/bq24190_charger.h
> @@ -9,8 +9,12 @@
> #ifndef _BQ24190_CHARGER_H_
> #define _BQ24190_CHARGER_H_
>
> +#include <linux/power_supply.h>
> +
> struct bq24190_platform_data {
> bool no_register_reset;
> + int (*get_ext_bat_property)(enum power_supply_property prop,
> + union power_supply_propval *val);
> };
>
> #endif