| Message ID | 1442339914-25843-6-git-send-email-dannenberg@ti.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 16.09.2015 02:58, Andreas Dannenberg wrote: > 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@ti.com> > --- > drivers/power/bq24257_charger.c | 49 ++++++++++++++++++++++++++++++++++++----- > 1 file changed, 43 insertions(+), 6 deletions(-) > > diff --git a/drivers/power/bq24257_charger.c b/drivers/power/bq24257_charger.c > index 55e4ee4..d7488cf 100644 > --- a/drivers/power/bq24257_charger.c > +++ b/drivers/power/bq24257_charger.c > @@ -103,6 +103,7 @@ struct bq24257_device { > struct mutex lock; /* protect state data */ > > bool in_ilimit_autoset_disable; > + bool pg_gpio_disable; > }; > > static bool bq24257_is_volatile_reg(struct device *dev, unsigned int reg) > @@ -356,7 +357,26 @@ 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_gpio_disable) > + /* > + * 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; > + } > + else > + state->power_good = !gpiod_get_value_cansleep(bq->pg); > > return 0; > } > @@ -676,7 +696,7 @@ static int bq24257_pg_gpio_probe(struct bq24257_device *bq) > { > bq->pg = devm_gpiod_get_index(bq->dev, BQ24257_PG_GPIO, 0, GPIOD_IN); > if (IS_ERR(bq->pg)) { > - dev_err(bq->dev, "could not probe PG pin\n"); > + dev_info(bq->dev, "could not probe PG pin\n"); I think if pg-gpio is provided (e.g. by DTS) but it is invalid (return value != ENOENT) then it is an error you could print. The driver will fallback to the software method but still user/developer may want to notice the error (e.g. error in DTS). Anyway it is up to you, rest looks good: Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Sep 16, 2015 at 02:41:13PM +0900, Krzysztof Kozlowski wrote: > On 16.09.2015 02:58, Andreas Dannenberg wrote: > > @@ -676,7 +696,7 @@ static int bq24257_pg_gpio_probe(struct bq24257_device *bq) > > { > > bq->pg = devm_gpiod_get_index(bq->dev, BQ24257_PG_GPIO, 0, GPIOD_IN); > > if (IS_ERR(bq->pg)) { > > - dev_err(bq->dev, "could not probe PG pin\n"); > > + dev_info(bq->dev, "could not probe PG pin\n"); > > I think if pg-gpio is provided (e.g. by DTS) but it is invalid (return > value != ENOENT) then it is an error you could print. The driver will > fallback to the software method but still user/developer may want to > notice the error (e.g. error in DTS). > > Anyway it is up to you, rest looks good: Krzysztof, I looked at this closer and all the error scenarios I could come up with to test regarding the pin definition in DT (wrong pin numbers, missing definition altogether) all generated an -ENOENT coming out of devm_gpiod_get_index() with no differentiation between the cases. I'm sure there is some way to accomplish that but for the time being I left the refinement between dev_err() and dev_info() alone. Regards, -- Andreas Dannenberg Texas Instruments Inc -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/power/bq24257_charger.c b/drivers/power/bq24257_charger.c index 55e4ee4..d7488cf 100644 --- a/drivers/power/bq24257_charger.c +++ b/drivers/power/bq24257_charger.c @@ -103,6 +103,7 @@ struct bq24257_device { struct mutex lock; /* protect state data */ bool in_ilimit_autoset_disable; + bool pg_gpio_disable; }; static bool bq24257_is_volatile_reg(struct device *dev, unsigned int reg) @@ -356,7 +357,26 @@ 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_gpio_disable) + /* + * 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; + } + else + state->power_good = !gpiod_get_value_cansleep(bq->pg); return 0; } @@ -676,7 +696,7 @@ static int bq24257_pg_gpio_probe(struct bq24257_device *bq) { bq->pg = devm_gpiod_get_index(bq->dev, BQ24257_PG_GPIO, 0, GPIOD_IN); if (IS_ERR(bq->pg)) { - dev_err(bq->dev, "could not probe PG pin\n"); + dev_info(bq->dev, "could not probe PG pin\n"); return PTR_ERR(bq->pg); } @@ -810,10 +830,27 @@ 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 we + * explicitly disable this feature for this device and instead use + * a SW-based approach to determine the PG state. + */ + if (bq->chip == BQ24250) + bq->pg_gpio_disable = true; + + /* + * For devices that do have a dedicated PG pin go ahead and probe it, + * using the SW-based approach as a fall back solution. Note that the + * use of the dedicated pin is preferred. + */ + if (!bq->pg_gpio_disable) { + ret = bq24257_pg_gpio_probe(bq); + if (ret < 0) { + dev_info(bq->dev, + "using SW-based power-good detection\n"); + bq->pg_gpio_disable = true; + } + } /* reset all registers to defaults */ ret = bq24257_field_write(bq, F_RESET, 1);
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@ti.com> --- drivers/power/bq24257_charger.c | 49 ++++++++++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 6 deletions(-)