2021-02-23 19:58:01

by Matthias Schiffer

[permalink] [raw]
Subject: [PATCH 1/3] power: supply: bq27xxx: fix sign of current_now for newer ICs

Commit cd060b4d0868 ("power: supply: bq27xxx: fix polarity of current_now")
changed the sign of current_now for all bq27xxx variants, but on BQ28Z610
I'm now seeing negated values *with* that patch.

The GTA04/Openmoko device that was used for testing uses a BQ27000 or
BQ27010 IC, so I assume only the BQ27XXX_O_ZERO code path was incorrect.
Revert the behaviour for newer ICs.

Fixes: cd060b4d0868 "power: supply: bq27xxx: fix polarity of current_now"
Signed-off-by: Matthias Schiffer <[email protected]>
---

@Andreas Kemnade: It would be great to get a confirmation that the
Openmoko battery indeed uses BQ27000/BQ27010 - I was having some trouble
finding that information.


drivers/power/supply/bq27xxx_battery.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/power/supply/bq27xxx_battery.c b/drivers/power/supply/bq27xxx_battery.c
index 4c4a7b1c64c5..cb6ebd2f905e 100644
--- a/drivers/power/supply/bq27xxx_battery.c
+++ b/drivers/power/supply/bq27xxx_battery.c
@@ -1827,7 +1827,7 @@ static int bq27xxx_battery_current(struct bq27xxx_device_info *di,
val->intval = curr * BQ27XXX_CURRENT_CONSTANT / BQ27XXX_RS;
} else {
/* Other gauges return signed value */
- val->intval = -(int)((s16)curr) * 1000;
+ val->intval = (int)((s16)curr) * 1000;
}

return 0;
--
2.17.1


2021-02-23 19:58:54

by Matthias Schiffer

[permalink] [raw]
Subject: [PATCH 3/3] power: supply: bq27xxx: make status more robust

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 <[email protected]>
---
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