Hi Jonathan,
On Sat, Dec 05, 2020 at 03:38:48PM +0000, Jonathan Cameron wrote:
> On Wed, 2 Dec 2020 10:33:22 +0100
> Stephan Gerhold <stephan@xxxxxxxxxxx> wrote:
>
> > BMG160 needs VDD and VDDIO regulators that might need to be explicitly
> > enabled. Add some rudimentary support to obtain and enable these
> > regulators during probe() and disable them during remove()
> > or on the error path.
> >
> > Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx>
>
> This one is a bit tricky due to the extensive use of devm_ managed
> cleanup. Normally I'd be very fussy about ensuring remove order
> is precise reverse of probe, but in this driver it isn't quite
> already, due to that chip_init being before the interrupt allocation.
>
> Having said that I'd rather not make it worse. Would you mind
> using automated clean up of the regulator_enable as well via
> devm_add_action_or_reset() call?
>
Good point, devm_add_action_or_reset() definitely looks better for this
driver. I will send a v2 with just the bmg160 part shortly.
> As a side note, should we not have more cleanup of chip_init()
> in error paths, specifically putting the device into it's suspended
> mode? Obviously nothing to do with your patch...
>
I'm not sure. I guess when bmg160_chip_init() fails there is some kind
of communication problem or a problem with the chip. Chances are that
putting it back into suspend mode would also fail.
But I don't really know enough about the hardware to say more. :)
I have also fixed your other comments below in v2.
Thanks!
Stephan
>
> > ---
> > drivers/iio/gyro/bmg160_core.c | 38 +++++++++++++++++++++++++++-------
> > 1 file changed, 31 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/iio/gyro/bmg160_core.c b/drivers/iio/gyro/bmg160_core.c
> > index 2d5015801a75..4baa4169c5a2 100644
> > --- a/drivers/iio/gyro/bmg160_core.c
> > +++ b/drivers/iio/gyro/bmg160_core.c
> > @@ -19,6 +19,7 @@
> > #include <linux/iio/trigger_consumer.h>
> > #include <linux/iio/triggered_buffer.h>
> > #include <linux/regmap.h>
> > +#include <linux/regulator/consumer.h>
> > #include "bmg160.h"
> >
> > #define BMG160_IRQ_NAME "bmg160_event"
> > @@ -92,6 +93,7 @@
> >
> > struct bmg160_data {
> > struct regmap *regmap;
> > + struct regulator_bulk_data regulators[2];
> > struct iio_trigger *dready_trig;
> > struct iio_trigger *motion_trig;
> > struct iio_mount_matrix orientation;
> > @@ -1077,14 +1079,28 @@ int bmg160_core_probe(struct device *dev, struct regmap *regmap, int irq,
> > data->irq = irq;
> > data->regmap = regmap;
> >
> > + data->regulators[0].supply = "vdd";
> > + data->regulators[1].supply = "vddio";
> > + ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(data->regulators),
> > + data->regulators);
> > + if (ret)
> > + return dev_err_probe(dev, ret, "Failed to get regulators\n");
> > +
> > ret = iio_read_mount_matrix(dev, "mount-matrix",
> > &data->orientation);
> > if (ret)
> > return ret;
>
> Why not put regulator get and enable together?
>
> >
> > + ret = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
> > + data->regulators);
> > + if (ret < 0) {
> > + dev_err(dev, "Failed to enable regulators: %d\n", ret);
> > + return ret;
> > + }
> > +
>
> If you were to use devm_add_action_or_reset() and a trivial wrapper
> the disable would be automated, simplifying the error handling etc.
>
> > ret = bmg160_chip_init(data);
> > if (ret < 0)
> > - return ret;
> > + goto err_regulator_disable;
> >
> > mutex_init(&data->mutex);
> >
> > @@ -1107,28 +1123,32 @@ int bmg160_core_probe(struct device *dev, struct regmap *regmap, int irq,
> > BMG160_IRQ_NAME,
> > indio_dev);
> > if (ret)
> > - return ret;
> > + goto err_regulator_disable;
> >
> > data->dready_trig = devm_iio_trigger_alloc(dev,
> > "%s-dev%d",
> > indio_dev->name,
> > indio_dev->id);
> > - if (!data->dready_trig)
> > - return -ENOMEM;
> > + if (!data->dready_trig) {
> > + ret = -ENOMEM;
> > + goto err_regulator_disable;
> > + }
> >
> > data->motion_trig = devm_iio_trigger_alloc(dev,
> > "%s-any-motion-dev%d",
> > indio_dev->name,
> > indio_dev->id);
> > - if (!data->motion_trig)
> > - return -ENOMEM;
> > + if (!data->motion_trig) {
> > + ret = -ENOMEM;
> > + goto err_regulator_disable;
> > + }
> >
> > data->dready_trig->dev.parent = dev;
> > data->dready_trig->ops = &bmg160_trigger_ops;
> > iio_trigger_set_drvdata(data->dready_trig, indio_dev);
> > ret = iio_trigger_register(data->dready_trig);
> > if (ret)
> > - return ret;
> > + goto err_regulator_disable;
> >
> > data->motion_trig->dev.parent = dev;
> > data->motion_trig->ops = &bmg160_trigger_ops;
> > @@ -1174,6 +1194,8 @@ int bmg160_core_probe(struct device *dev, struct regmap *regmap, int irq,
> > iio_trigger_unregister(data->dready_trig);
> > if (data->motion_trig)
> > iio_trigger_unregister(data->motion_trig);
> > +err_regulator_disable:
> > + regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
> >
> > return ret;
> > }
> > @@ -1200,6 +1222,8 @@ void bmg160_core_remove(struct device *dev)
> > mutex_lock(&data->mutex);
> > bmg160_set_mode(data, BMG160_MODE_DEEP_SUSPEND);
> > mutex_unlock(&data->mutex);
> > +
> > + regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
> > }
> > EXPORT_SYMBOL_GPL(bmg160_core_remove);
> >
>
