Re: [PATCH v2 2/2] iio: vncl4000: Enable runtime pm for vcnl4200/4040

Guido Günther
2020-02-02T21:17:44Z

Hi Jonathan,
On Sun, Feb 02, 2020 at 09:34:08AM +0000, Jonathan Cameron wrote:
> On Thu, 30 Jan 2020 14:42:36 +0100
> Guido Günther <agx@sigxcpu.org> wrote:
>
> > This is modelled after the vcnl4035 driver. For the vcnl40{0,1,2}0
> > we don't do anything since they use on demand measurement.
> >
> > Signed-off-by: Guido Günther <agx@sigxcpu.org>
> Hi Guido,
>
> A few minor things inline, but otherwise looks good to me.
>
> Thanks,
>
> Jonathan
>
> > ---
> > drivers/iio/light/vcnl4000.c | 135 ++++++++++++++++++++++++++++++++---
> > 1 file changed, 124 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
> > index 8f198383626b..1395875d9553 100644
> > --- a/drivers/iio/light/vcnl4000.c
> > +++ b/drivers/iio/light/vcnl4000.c
> > @@ -22,6 +22,7 @@
> > #include <linux/i2c.h>
> > #include <linux/err.h>
> > #include <linux/delay.h>
> > +#include <linux/pm_runtime.h>
> >
> > #include <linux/iio/iio.h>
> > #include <linux/iio/sysfs.h>
> > @@ -57,6 +58,8 @@
> > #define VCNL4000_AL_OD BIT(4) /* start on-demand ALS measurement */
> > #define VCNL4000_PS_OD BIT(3) /* start on-demand proximity measurement */
> >
> > +#define VCNL4000_SLEEP_DELAY_MS 2000 /* before we enter pm_runtime_suspend */
> > +
> > enum vcnl4000_device_ids {
> > VCNL4000,
> > VCNL4010,
> > @@ -87,6 +90,7 @@ struct vcnl4000_chip_spec {
> > int (*init)(struct vcnl4000_data *data);
> > int (*measure_light)(struct vcnl4000_data *data, int *val);
> > int (*measure_proximity)(struct vcnl4000_data *data, int *val);
> > + int (*set_power_state)(struct vcnl4000_data *data, bool on);
> > };
> >
> > static const struct i2c_device_id vcnl4000_id[] = {
> > @@ -99,6 +103,12 @@ static const struct i2c_device_id vcnl4000_id[] = {
> > };
> > MODULE_DEVICE_TABLE(i2c, vcnl4000_id);
> >
> > +static int vcnl4000_set_power_state(struct vcnl4000_data *data, bool on)
> > +{
> > + /* no suspend op */
> > + return 0;
> > +}
> > +
> > static int vcnl4000_init(struct vcnl4000_data *data)
> > {
> > int ret, prod_id;
> > @@ -127,9 +137,31 @@ static int vcnl4000_init(struct vcnl4000_data *data)
> > data->al_scale = 250000;
> > mutex_init(&data->vcnl4000_lock);
> >
> > + ret = data->chip_spec->set_power_state(data, true);
> > + if (ret < 0)
> > + return ret;
> > +
> > return 0;
> > };
> >
> > +static int vcnl4200_set_power_state(struct vcnl4000_data *data, bool on)
> > +{
> > + u16 val = on ? 0 /* power on */ : 1 /* shut down */;
> > + int ret;
> > +
> > + ret = i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, val);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, val);
> > + if (ret < 0)
> > + return ret;
> > +
> > + /* Wait at least one integration cycle before fetching data */
> > + data->vcnl4200_al.last_measurement = ktime_get();
> > + data->vcnl4200_ps.last_measurement = ktime_get();
>
> Hmm. Feels like these only really make sense if we are turning on?
> They may do no harm in the off path, but better if the code makes
> it clear they are irrelevant in that path.

You're right, it doesn't matter in the off path but it's clearer when
only doing it in the 'on' path.

> No return value.

Duh, wonder why gcc didn't warn about that.

>
> i.e. return 0;
> > +}
> > +
> > static int vcnl4200_init(struct vcnl4000_data *data)
> > {
> > int ret, id;
> > @@ -155,14 +187,6 @@ static int vcnl4200_init(struct vcnl4000_data *data)
> >
> > data->rev = (ret >> 8) & 0xf;
> >
> > - /* Set defaults and enable both channels */
> > - ret = i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, 0);
> > - if (ret < 0)
> > - return ret;
> > - ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, 0);
> > - if (ret < 0)
> > - return ret;
> > -
> > data->vcnl4200_al.reg = VCNL4200_AL_DATA;
> > data->vcnl4200_ps.reg = VCNL4200_PS_DATA;
> > switch (id) {
> > @@ -180,11 +204,13 @@ static int vcnl4200_init(struct vcnl4000_data *data)
> > data->al_scale = 120000;
> > break;
> > }
> > - data->vcnl4200_al.last_measurement = ktime_set(0, 0);
> > - data->vcnl4200_ps.last_measurement = ktime_set(0, 0);
> > mutex_init(&data->vcnl4200_al.lock);
> > mutex_init(&data->vcnl4200_ps.lock);
> >
> > + ret = data->chip_spec->set_power_state(data, true);
> > + if (ret < 0)
> > + return ret;
> > +
> > return 0;
> > };
> >
> > @@ -291,24 +317,28 @@ static const struct vcnl4000_chip_spec vcnl4000_chip_spec_cfg[] = {
> > .init = vcnl4000_init,
> > .measure_light = vcnl4000_measure_light,
> > .measure_proximity = vcnl4000_measure_proximity,
> > + .set_power_state = vcnl4000_set_power_state,
> > },
> > [VCNL4010] = {
> > .prod = "VCNL4010/4020",
> > .init = vcnl4000_init,
> > .measure_light = vcnl4000_measure_light,
> > .measure_proximity = vcnl4000_measure_proximity,
> > + .set_power_state = vcnl4000_set_power_state,
> > },
> > [VCNL4040] = {
> > .prod = "VCNL4040",
> > .init = vcnl4200_init,
> > .measure_light = vcnl4200_measure_light,
> > .measure_proximity = vcnl4200_measure_proximity,
> > + .set_power_state = vcnl4200_set_power_state,
> > },
> > [VCNL4200] = {
> > .prod = "VCNL4200",
> > .init = vcnl4200_init,
> > .measure_light = vcnl4200_measure_light,
> > .measure_proximity = vcnl4200_measure_proximity,
> > + .set_power_state = vcnl4200_set_power_state,
> > },
> > };
> >
> > @@ -323,6 +353,23 @@ static const struct iio_chan_spec vcnl4000_channels[] = {
> > }
> > };
> >
> > +static int vcnl4000_set_pm_runtime_state(struct vcnl4000_data *data, bool on)
> > +{
> > + struct device *dev = &data->client->dev;
> > + int ret;
> > +
> > + if (on) {
> > + ret = pm_runtime_get_sync(dev);
> > + if (ret < 0)
> > + pm_runtime_put_noidle(dev);
> > + } else {
> > + pm_runtime_mark_last_busy(dev);
> > + ret = pm_runtime_put_autosuspend(dev);
> > + }
> > +
> > + return ret;
> > +}
> > +
> > static int vcnl4000_read_raw(struct iio_dev *indio_dev,
> > struct iio_chan_spec const *chan,
> > int *val, int *val2, long mask)
> > @@ -332,6 +379,10 @@ static int vcnl4000_read_raw(struct iio_dev *indio_dev,
> >
> > switch (mask) {
> > case IIO_CHAN_INFO_RAW:
> > + ret = vcnl4000_set_pm_runtime_state(data, true);
> > + if (ret < 0)
> > + return ret;
> > +
> > switch (chan->type) {
> > case IIO_LIGHT:
> > ret = data->chip_spec->measure_light(data, val);
> > @@ -346,6 +397,7 @@ static int vcnl4000_read_raw(struct iio_dev *indio_dev,
> > default:
> > ret = -EINVAL;
> > }
> > + vcnl4000_set_pm_runtime_state(data, false);
> > return ret;
> > case IIO_CHAN_INFO_SCALE:
> > if (chan->type != IIO_LIGHT)
> > @@ -394,7 +446,22 @@ static int vcnl4000_probe(struct i2c_client *client,
> > indio_dev->name = VCNL4000_DRV_NAME;
> > indio_dev->modes = INDIO_DIRECT_MODE;
> >
> > - return devm_iio_device_register(&client->dev, indio_dev);
> > + ret = pm_runtime_set_active(&client->dev);
> > + if (ret < 0)
> > + goto fail_poweroff;
> > +
> > + ret = iio_device_register(indio_dev);
> > + if (ret < 0)
> > + goto fail_poweroff;
> > +
> > + pm_runtime_enable(&client->dev);
> > + pm_runtime_set_autosuspend_delay(&client->dev, VCNL4000_SLEEP_DELAY_MS);
> > + pm_runtime_use_autosuspend(&client->dev);
> > +
> > + return 0;
> > +fail_poweroff:
> > + data->chip_spec->set_power_state(data, false);
> > + return ret;
> > }
> >
> > static const struct of_device_id vcnl_4000_of_match[] = {
> > @@ -422,13 +489,59 @@ static const struct of_device_id vcnl_4000_of_match[] = {
> > };
> > MODULE_DEVICE_TABLE(of, vcnl_4000_of_match);
> >
> > +static int vcnl4000_remove(struct i2c_client *client)
> > +{
> > + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> > + struct vcnl4000_data *data = iio_priv(indio_dev);
> > +
> > + pm_runtime_dont_use_autosuspend(&client->dev);
> > + pm_runtime_disable(&client->dev);
> > + iio_device_unregister(indio_dev);
> > + pm_runtime_set_suspended(&client->dev);
> > +
> > + return data->chip_spec->set_power_state(data, false);
> > +}
> > +
> > +static int __maybe_unused vcnl4000_runtime_suspend(struct device *dev)
> > +{
> > + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> > + struct vcnl4000_data *data = iio_priv(indio_dev);
> > + int ret;
> > +
> > + ret = data->chip_spec->set_power_state(data, false);
> > +
> > + return ret;
>
> return data->chip_spec...
>
> > +}
> > +
> > +static int __maybe_unused vcnl4000_runtime_resume(struct device *dev)
> > +{
> > + struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> > + struct vcnl4000_data *data = iio_priv(indio_dev);
> > + int ret;
> > +
> > + ret = data->chip_spec->set_power_state(data, true);
> > + if (ret < 0)
> > + return ret;
>
> I would define the set_power_state callback to return only < 0 for error
> and 0 for no error. (already true).
>
> then
>
> return data->chip_spec->set_power_state(data, true);

Both returns simplified and also the one in vcnl4000_init.

Thanks for having a look,
-- Guido

>
> > +
> > + return 0;
> > +}
> > +
> > +static const struct dev_pm_ops vcnl4000_pm_ops = {
> > + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> > + pm_runtime_force_resume)
> > + SET_RUNTIME_PM_OPS(vcnl4000_runtime_suspend,
> > + vcnl4000_runtime_resume, NULL)
> > +};
> > +
> > static struct i2c_driver vcnl4000_driver = {
> > .driver = {
> > .name = VCNL4000_DRV_NAME,
> > + .pm = &vcnl4000_pm_ops,
> > .of_match_table = vcnl_4000_of_match,
> > },
> > .probe = vcnl4000_probe,
> > .id_table = vcnl4000_id,
> > + .remove = vcnl4000_remove,
> > };
> >
> > module_i2c_driver(vcnl4000_driver);
>