Re: [PATCH v3 2/2] iio: accel: fxls8962af: add wake on event

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 30 Aug 2021 10:10:32 +0200
Sean Nyekjaer <sean@geanix.com> wrote:

> This adds ways for the SoC to wake from accelerometer wake events.
> 
> In the suspend function we skip disabling the sensor if wakeup-source
> and events are activated.
> 
> If buffered reads are enabled they will be deactivated before suspend.
> As the onboard buffer is only holding up to 32 12-bit X/Y/Z data
> triplets.
> 
> Signed-off-by: Sean Nyekjaer <sean@geanix.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
lgtm

J
> ---
> Changes since v1:
>  - Fixed comments fron Andy (Thanks)
> 
>  drivers/iio/accel/fxls8962af-core.c | 46 +++++++++++++++++++++++++++--
>  1 file changed, 44 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/accel/fxls8962af-core.c b/drivers/iio/accel/fxls8962af-core.c
> index dd639420fb0f..ef0f6560953c 100644
> --- a/drivers/iio/accel/fxls8962af-core.c
> +++ b/drivers/iio/accel/fxls8962af-core.c
> @@ -160,6 +160,7 @@ struct fxls8962af_data {
>  	} scan;
>  	int64_t timestamp, old_timestamp;	/* Only used in hw fifo mode. */
>  	struct iio_mount_matrix orientation;
> +	int irq;
>  	u8 watermark;
>  	u8 enable_event;
>  	u16 lower_thres;
> @@ -1123,6 +1124,7 @@ int fxls8962af_core_probe(struct device *dev, struct regmap *regmap, int irq)
>  	data = iio_priv(indio_dev);
>  	dev_set_drvdata(dev, indio_dev);
>  	data->regmap = regmap;
> +	data->irq = irq;
>  
>  	ret = iio_read_mount_matrix(dev, &data->orientation);
>  	if (ret)
> @@ -1192,6 +1194,9 @@ int fxls8962af_core_probe(struct device *dev, struct regmap *regmap, int irq)
>  	if (ret)
>  		return ret;
>  
> +	if (device_property_read_bool(dev, "wakeup-source"))
> +		device_init_wakeup(dev, true);
> +
>  	return devm_iio_device_register(dev, indio_dev);
>  }
>  EXPORT_SYMBOL_GPL(fxls8962af_core_probe);
> @@ -1217,9 +1222,46 @@ static int __maybe_unused fxls8962af_runtime_resume(struct device *dev)
>  	return fxls8962af_active(data);
>  }
>  
> +static int __maybe_unused fxls8962af_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct fxls8962af_data *data = iio_priv(indio_dev);
> +
> +	if (device_may_wakeup(dev) && data->enable_event) {
> +		enable_irq_wake(data->irq);
> +
> +		/*
> +		 * Disable buffer, as the buffer is so small the device will wake
> +		 * almost immediately.
> +		 */
> +		if (iio_buffer_enabled(indio_dev))
> +			fxls8962af_buffer_predisable(indio_dev);
> +	} else {
> +		fxls8962af_runtime_suspend(dev);
> +	}
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused fxls8962af_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct fxls8962af_data *data = iio_priv(indio_dev);
> +
> +	if (device_may_wakeup(dev) && data->enable_event) {
> +		disable_irq_wake(data->irq);
> +
> +		if (iio_buffer_enabled(indio_dev))
> +			fxls8962af_buffer_postenable(indio_dev);
> +	} else {
> +		fxls8962af_runtime_resume(dev);
> +	}
> +
> +	return 0;
> +}
> +
>  const struct dev_pm_ops fxls8962af_pm_ops = {
> -	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> -				pm_runtime_force_resume)
> +	SET_SYSTEM_SLEEP_PM_OPS(fxls8962af_suspend, fxls8962af_resume)
>  	SET_RUNTIME_PM_OPS(fxls8962af_runtime_suspend,
>  			   fxls8962af_runtime_resume, NULL)
>  };