A software-based approach for determining the charger's input voltage
"Power Good" state is introduced for devices like the bq24250 which
don't have a dedicated hardware pin for that purpose. This SW-based
approach is also used for other devices (with dedicated PG pin) as a
fall back solution if that pin is not configured to be used through
"pg-gpios".
Signed-off-by: Andreas Dannenberg <dannenberg@xxxxxx>
---
drivers/power/bq24257_charger.c | 49 ++++++++++++++++++++++++++++++++---------
1 file changed, 39 insertions(+), 10 deletions(-)
diff --git a/drivers/power/bq24257_charger.c b/drivers/power/bq24257_charger.c
index 7bbff80..5800697 100644
--- a/drivers/power/bq24257_charger.c
+++ b/drivers/power/bq24257_charger.c
@@ -359,7 +359,26 @@ static int bq24257_get_chip_state(struct bq24257_device *bq,
state->fault = ret;
- state->power_good = !gpiod_get_value_cansleep(bq->pg);
+ if (bq->pg)
+ state->power_good = !gpiod_get_value_cansleep(bq->pg);
+ else
+ /*
+ * If we have a chip without a dedicated power-good GPIO or
+ * some other explicit bit that would provide this information
+ * assume the power is good if there is no supply related
+ * fault - and not good otherwise. There is a possibility for
+ * other errors to mask that power in fact is not good but this
+ * is probably the best we can do here.
+ */
+ switch (state->fault) {
+ case FAULT_INPUT_OVP:
+ case FAULT_INPUT_UVLO:
+ case FAULT_INPUT_LDO_LOW:
+ state->power_good = false;
+ break;
+ default:
+ state->power_good = true;
+ }
return 0;
}
@@ -651,15 +670,18 @@ static int bq24257_power_supply_init(struct bq24257_device *bq)
return PTR_ERR_OR_ZERO(bq->charger);
}
-static int bq24257_pg_gpio_probe(struct bq24257_device *bq)
+static void bq24257_pg_gpio_probe(struct bq24257_device *bq)
{
- bq->pg = devm_gpiod_get_index(bq->dev, BQ24257_PG_GPIO, 0, GPIOD_IN);
+ bq->pg = devm_gpiod_get_optional(bq->dev, BQ24257_PG_GPIO, GPIOD_IN);
+
if (IS_ERR(bq->pg)) {
- dev_err(bq->dev, "could not probe PG pin\n");
- return PTR_ERR(bq->pg);
+ dev_err(bq->dev, "error probing PG pin\n");
+ bq->pg = NULL;
+ return;
}
- return 0;
+ if (bq->pg)
+ dev_dbg(bq->dev, "probed PG pin = %d\n", desc_to_gpio(bq->pg));
}
static int bq24257_fw_probe(struct bq24257_device *bq)
@@ -789,10 +811,17 @@ static int bq24257_probe(struct i2c_client *client,
INIT_DELAYED_WORK(&bq->iilimit_setup_work,
bq24257_iilimit_setup_work);
- /* we can only check Power Good status by probing the PG pin */
- ret = bq24257_pg_gpio_probe(bq);
- if (ret < 0)
- return ret;
+ /*
+ * The BQ24250 doesn't have a dedicated Power Good (PG) pin so let's
+ * not probe for it and instead use a SW-based approach to determine
+ * the PG state. We also use a SW-based approach for all other devices
+ * if the PG pin is either not defined or can't be probed.
+ */
+ if (bq->chip != BQ24250)
+ bq24257_pg_gpio_probe(bq);
+
+ if (!bq->pg)
+ dev_info(bq->dev, "using SW-based power-good detection\n");
/* reset all registers to defaults */
ret = bq24257_field_write(bq, F_RESET, 1);
--
1.9.1
--
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