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Date: Mon, 15 Mar 2021 02:55:34 +0100
From: Sebastian Reichel <sre@...nel.org>
To: Matthias Schiffer <matthias.schiffer@...tq-group.com>
Cc: Pali Rohár <pali@...nel.org>,
Andreas Kemnade <andreas@...nade.info>,
linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 3/3] power: supply: bq27xxx: make status more robust
Hi,
On Wed, Mar 03, 2021 at 10:54:20AM +0100, Matthias Schiffer wrote:
> There are multiple issues in bq27xxx_battery_status():
>
> - On BQ28Q610 is was observed that the "full" flag may be set even while
> the battery is charging or discharging. With the current logic to make
> "full" override everything else, it look a very long time (>20min) for
> the status to change from "full" to "discharging" after unplugging the
> supply on a device with low power consumption
> - The POWER_SUPPLY_STATUS_NOT_CHARGING check depends on
> power_supply_am_i_supplied(), which will not work when the supply
> doesn't exist as a separate device known to Linux
>
> We can solve both issues by deriving the status from the current instead
> of the flags field. The flags are now only used to distinguish "full"
> from "not charging", and to determine the sign of the current on
> BQ27XXX_O_ZERO devices.
>
> Signed-off-by: Matthias Schiffer <matthias.schiffer@...tq-group.com>
> ---
Thanks, queued.
-- Sebastian
>
> v2: no changes
>
> drivers/power/supply/bq27xxx_battery.c | 88 +++++++++++++-------------
> 1 file changed, 43 insertions(+), 45 deletions(-)
>
> diff --git a/drivers/power/supply/bq27xxx_battery.c b/drivers/power/supply/bq27xxx_battery.c
> index 20e1dc8a87cf..b62a8cfd9d09 100644
> --- a/drivers/power/supply/bq27xxx_battery.c
> +++ b/drivers/power/supply/bq27xxx_battery.c
> @@ -1777,14 +1777,27 @@ static void bq27xxx_battery_poll(struct work_struct *work)
> schedule_delayed_work(&di->work, poll_interval * HZ);
> }
>
> +static bool bq27xxx_battery_is_full(struct bq27xxx_device_info *di, int flags)
> +{
> + if (di->opts & BQ27XXX_O_ZERO)
> + return (flags & BQ27000_FLAG_FC);
> + else if (di->opts & BQ27Z561_O_BITS)
> + return (flags & BQ27Z561_FLAG_FC);
> + else
> + return (flags & BQ27XXX_FLAG_FC);
> +}
> +
> /*
> - * Return the battery average current in µA
> + * Return the battery average current in µA and the status
> * Note that current can be negative signed as well
> * Or 0 if something fails.
> */
> -static int bq27xxx_battery_current(struct bq27xxx_device_info *di,
> - union power_supply_propval *val)
> +static int bq27xxx_battery_current_and_status(
> + struct bq27xxx_device_info *di,
> + union power_supply_propval *val_curr,
> + union power_supply_propval *val_status)
> {
> + bool single_flags = (di->opts & BQ27XXX_O_ZERO);
> int curr;
> int flags;
>
> @@ -1794,17 +1807,39 @@ static int bq27xxx_battery_current(struct bq27xxx_device_info *di,
> return curr;
> }
>
> + flags = bq27xxx_read(di, BQ27XXX_REG_FLAGS, single_flags);
> + if (flags < 0) {
> + dev_err(di->dev, "error reading flags\n");
> + return flags;
> + }
> +
> if (di->opts & BQ27XXX_O_ZERO) {
> - flags = bq27xxx_read(di, BQ27XXX_REG_FLAGS, true);
> if (!(flags & BQ27000_FLAG_CHGS)) {
> dev_dbg(di->dev, "negative current!\n");
> curr = -curr;
> }
>
> - val->intval = curr * BQ27XXX_CURRENT_CONSTANT / BQ27XXX_RS;
> + curr = curr * BQ27XXX_CURRENT_CONSTANT / BQ27XXX_RS;
> } else {
> /* Other gauges return signed value */
> - val->intval = (int)((s16)curr) * 1000;
> + curr = (int)((s16)curr) * 1000;
> + }
> +
> + if (val_curr)
> + val_curr->intval = curr;
> +
> + if (val_status) {
> + if (curr > 0) {
> + val_status->intval = POWER_SUPPLY_STATUS_CHARGING;
> + } else if (curr < 0) {
> + val_status->intval = POWER_SUPPLY_STATUS_DISCHARGING;
> + } else {
> + if (bq27xxx_battery_is_full(di, flags))
> + val_status->intval = POWER_SUPPLY_STATUS_FULL;
> + else
> + val_status->intval =
> + POWER_SUPPLY_STATUS_NOT_CHARGING;
> + }
> }
>
> return 0;
> @@ -1836,43 +1871,6 @@ static int bq27xxx_battery_pwr_avg(struct bq27xxx_device_info *di,
> return 0;
> }
>
> -static int bq27xxx_battery_status(struct bq27xxx_device_info *di,
> - union power_supply_propval *val)
> -{
> - int status;
> -
> - if (di->opts & BQ27XXX_O_ZERO) {
> - if (di->cache.flags & BQ27000_FLAG_FC)
> - status = POWER_SUPPLY_STATUS_FULL;
> - else if (di->cache.flags & BQ27000_FLAG_CHGS)
> - status = POWER_SUPPLY_STATUS_CHARGING;
> - else
> - status = POWER_SUPPLY_STATUS_DISCHARGING;
> - } else if (di->opts & BQ27Z561_O_BITS) {
> - if (di->cache.flags & BQ27Z561_FLAG_FC)
> - status = POWER_SUPPLY_STATUS_FULL;
> - else if (di->cache.flags & BQ27Z561_FLAG_DIS_CH)
> - status = POWER_SUPPLY_STATUS_DISCHARGING;
> - else
> - status = POWER_SUPPLY_STATUS_CHARGING;
> - } else {
> - if (di->cache.flags & BQ27XXX_FLAG_FC)
> - status = POWER_SUPPLY_STATUS_FULL;
> - else if (di->cache.flags & BQ27XXX_FLAG_DSC)
> - status = POWER_SUPPLY_STATUS_DISCHARGING;
> - else
> - status = POWER_SUPPLY_STATUS_CHARGING;
> - }
> -
> - if ((status == POWER_SUPPLY_STATUS_DISCHARGING) &&
> - (power_supply_am_i_supplied(di->bat) > 0))
> - status = POWER_SUPPLY_STATUS_NOT_CHARGING;
> -
> - val->intval = status;
> -
> - return 0;
> -}
> -
> static int bq27xxx_battery_capacity_level(struct bq27xxx_device_info *di,
> union power_supply_propval *val)
> {
> @@ -1960,7 +1958,7 @@ static int bq27xxx_battery_get_property(struct power_supply *psy,
>
> switch (psp) {
> case POWER_SUPPLY_PROP_STATUS:
> - ret = bq27xxx_battery_status(di, val);
> + ret = bq27xxx_battery_current_and_status(di, NULL, val);
> break;
> case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> ret = bq27xxx_battery_voltage(di, val);
> @@ -1969,7 +1967,7 @@ static int bq27xxx_battery_get_property(struct power_supply *psy,
> val->intval = di->cache.flags < 0 ? 0 : 1;
> break;
> case POWER_SUPPLY_PROP_CURRENT_NOW:
> - ret = bq27xxx_battery_current(di, val);
> + ret = bq27xxx_battery_current_and_status(di, val, NULL);
> break;
> case POWER_SUPPLY_PROP_CAPACITY:
> ret = bq27xxx_simple_value(di->cache.capacity, val);
> --
> 2.17.1
>
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