| Message ID | 1442612399-341-6-git-send-email-dannenberg@ti.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
Hi, On Fri, Sep 18, 2015 at 04:39:53PM -0500, 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 502dd8a5..135cfd4 100644 > --- a/drivers/power/bq24257_charger.c > +++ b/drivers/power/bq24257_charger.c > @@ -107,6 +107,7 @@ struct bq24257_device { > struct mutex lock; /* protect state data */ > > bool iilimit_autoset_enable; > + bool pg_gpio_disable; I don't think this is required. > }; > > static bool bq24257_is_volatile_reg(struct device *dev, unsigned int reg) > @@ -360,7 +361,26 @@ 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); I guess you can just handle this like an optional gpio if(bq->pg) state->power_good = !gpiod_get_value_cansleep(bq->pg); else ... > > return 0; > } > @@ -680,7 +700,7 @@ 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); > } > > @@ -814,10 +834,27 @@ 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); -- Sebastian
On Tue, Sep 22, 2015 at 09:37:20PM +0200, Sebastian Reichel wrote: > Hi, > > On Fri, Sep 18, 2015 at 04:39:53PM -0500, Andreas Dannenberg wrote: > > - 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); > > I guess you can just handle this like an optional gpio > > if(bq->pg) > state->power_good = !gpiod_get_value_cansleep(bq->pg); > else > ... What happens when somebody wants to use GPIO number 0? According to gpio_is_valid() this is a valid GPIO so technically I should not use a check against zero to see whether the user has configured a GPIO for this purpose and wants to use it, no? 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
On Wed, Sep 23, 2015 at 02:34:27PM -0500, Andreas Dannenberg wrote: > On Tue, Sep 22, 2015 at 09:37:20PM +0200, Sebastian Reichel wrote: > > > > I guess you can just handle this like an optional gpio > > > > if(bq->pg) > > state->power_good = !gpiod_get_value_cansleep(bq->pg); > > else > > ... > > What happens when somebody wants to use GPIO number 0? According to > gpio_is_valid() this is a valid GPIO so technically I should not use a > check against zero to see whether the user has configured a GPIO for > this purpose and wants to use it, no? Ok never mind I figured it out. bq->pg is of type gpio_desc and not the actual GPIO number. Together with your suggestion of how to use gpiod_* in combination with platform data this will be a nice simplification! 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 502dd8a5..135cfd4 100644 --- a/drivers/power/bq24257_charger.c +++ b/drivers/power/bq24257_charger.c @@ -107,6 +107,7 @@ struct bq24257_device { struct mutex lock; /* protect state data */ bool iilimit_autoset_enable; + bool pg_gpio_disable; }; static bool bq24257_is_volatile_reg(struct device *dev, unsigned int reg) @@ -360,7 +361,26 @@ 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; } @@ -680,7 +700,7 @@ 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); } @@ -814,10 +834,27 @@ 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(-)