Re: [PATCH 1/8] iio: cros_ec: Relax sampling frequency before suspending

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 10 Aug 2017 20:25:56 -0700
Benson Leung <bleung@google.com> wrote:

> Hi Thierry,
> 
> On Fri, Aug 11, 2017 at 12:16:43AM +0200, Thierry Escande wrote:
> > From: Gwendal Grignou <gwendal@chromium.org>
> > 
> > If an application set a tight sampling frequency, given the interrupt
> > use is a wakup source, suspend will not happen: the kernel will receive
> > a wake up interrupt and will cancel the suspend process.
> > 
> > Given cros_ec sensors type is non wake up, this patch adds prepare and
> > complete callbacks to set 1s sampling period just before suspend. This
> > ensures the sensor hub will not be a source of interrupt during the
> > suspend process.
> > 
> > Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> > Signed-off-by: Thierry Escande <thierry.escande@collabora.com>  
> 
> Remember to copy the original author, Gwendal Also, this is an iio patch,
> so you should make sure to send this to linux-iio@vger.kernel.org and to 
> Jonathan Cameron <jic23@kernel.org> as well.
Thanks,

Looks fine to me
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> > ---
> >  .../iio/common/cros_ec_sensors/cros_ec_sensors.c   |  1 +
> >  .../common/cros_ec_sensors/cros_ec_sensors_core.c  | 49 ++++++++++++++++++++++
> >  .../common/cros_ec_sensors/cros_ec_sensors_core.h  |  2 +
> >  drivers/iio/light/cros_ec_light_prox.c             |  1 +
> >  4 files changed, 53 insertions(+)
> > 
> > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> > index 38e8783..116da2c 100644
> > --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> > @@ -292,6 +292,7 @@ MODULE_DEVICE_TABLE(platform, cros_ec_sensors_ids);
> >  static struct platform_driver cros_ec_sensors_platform_driver = {
> >  	.driver = {
> >  		.name	= "cros-ec-sensors",
> > +		.pm	= &cros_ec_sensors_pm_ops,
> >  	},
> >  	.probe		= cros_ec_sensors_probe,
> >  	.id_table	= cros_ec_sensors_ids,
> > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > index 416cae5..a620eb5 100644
> > --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > @@ -446,5 +446,54 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
> >  }
> >  EXPORT_SYMBOL_GPL(cros_ec_sensors_core_write);
> >  
> > +static int __maybe_unused cros_ec_sensors_prepare(struct device *dev)
> > +{
> > +	struct platform_device *pdev = to_platform_device(dev);
> > +	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> > +	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> > +
> > +	if (st->curr_sampl_freq == 0)
> > +		return 0;
> > +
> > +	/*
> > +	 * If the sensors are sampled at high frequency, we will not be able to
> > +	 * sleep. Set sampling to a long period if necessary.
> > +	 */
> > +	if (st->curr_sampl_freq < CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY) {
> > +		mutex_lock(&st->cmd_lock);
> > +		st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
> > +		st->param.ec_rate.data = CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY;
> > +		cros_ec_motion_send_host_cmd(st, 0);
> > +		mutex_unlock(&st->cmd_lock);
> > +	}
> > +	return 0;
> > +}
> > +
> > +static void __maybe_unused cros_ec_sensors_complete(struct device *dev)
> > +{
> > +	struct platform_device *pdev = to_platform_device(dev);
> > +	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> > +	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
> > +
> > +	if (st->curr_sampl_freq == 0)
> > +		return;
> > +
> > +	if (st->curr_sampl_freq < CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY) {
> > +		mutex_lock(&st->cmd_lock);
> > +		st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
> > +		st->param.ec_rate.data = st->curr_sampl_freq;
> > +		cros_ec_motion_send_host_cmd(st, 0);
> > +		mutex_unlock(&st->cmd_lock);
> > +	}
> > +}
> > +
> > +const struct dev_pm_ops cros_ec_sensors_pm_ops = {
> > +#ifdef CONFIG_PM_SLEEP
> > +	.prepare = cros_ec_sensors_prepare,
> > +	.complete = cros_ec_sensors_complete
> > +#endif
> > +};
> > +EXPORT_SYMBOL_GPL(cros_ec_sensors_pm_ops);
> > +
> >  MODULE_DESCRIPTION("ChromeOS EC sensor hub core functions");
> >  MODULE_LICENSE("GPL v2");
> > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.h b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.h
> > index 8bc2ca3..2edf68d 100644
> > --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.h
> > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.h
> > @@ -169,6 +169,8 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
> >  			       struct iio_chan_spec const *chan,
> >  			       int val, int val2, long mask);
> >  
> > +extern const struct dev_pm_ops cros_ec_sensors_pm_ops;
> > +
> >  /* List of extended channel specification for all sensors */
> >  extern const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[];
> >  
> > diff --git a/drivers/iio/light/cros_ec_light_prox.c b/drivers/iio/light/cros_ec_light_prox.c
> > index 7217223..f8658d4 100644
> > --- a/drivers/iio/light/cros_ec_light_prox.c
> > +++ b/drivers/iio/light/cros_ec_light_prox.c
> > @@ -279,6 +279,7 @@ MODULE_DEVICE_TABLE(platform, cros_ec_light_prox_ids);
> >  static struct platform_driver cros_ec_light_prox_platform_driver = {
> >  	.driver = {
> >  		.name	= "cros-ec-light-prox",
> > +		.pm	= &cros_ec_sensors_pm_ops,
> >  	},
> >  	.probe		= cros_ec_light_prox_probe,
> >  	.id_table	= cros_ec_light_prox_ids,
> > -- 
> > 2.7.4
> >   
>