Re: [PATCH v2 1/8] iio: cros_ec: Relax sampling frequency before suspending

From: Jonathan Cameron
Date: Sat Aug 12 2017 - 08:48:53 EST


On Fri, 11 Aug 2017 16:22:58 +0200
Thierry Escande <thierry.escande@xxxxxxxxxxxxx> wrote:

> From: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxx>
> Signed-off-by: Thierry Escande <thierry.escande@xxxxxxxxxxxxx>
Acked-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

Thanks,

Jonathan
> ---
> .../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,