Re: [PATCH v8 25/38] iio/scmi: Port driver to the new scmi_sensor_proto_ops interface

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Tue, 30 Mar 2021 14:47:11 +0100
Cristian Marussi <cristian.marussi@arm.com> wrote:

> Port the scmi iio driver to the new SCMI sensor interface based on
> protocol handles and common devm_get_ops().
> 
> Link: https://lore.kernel.org/r/20210316124903.35011-26-cristian.marussi@arm.com
> Cc: Jyoti Bhayana <jbhayana@google.com>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Cc: linux-iio@vger.kernel.org
> Tested-by: Florian Fainelli <f.fainelli@gmail.com>
> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Thanks for doing this, but beyond the more general question I put
in the reply to v7 of why we have this abstraction in the first place,
I'm fine with either version (v7 or v8).

I 'slightly' prefer this one I guess, but it actually hides the
more interesting question of whether the use of a protocol
related function to get access to functions that could just have
been exported from the original module actually makes sense?

Ah well. Let's go with the perfect not being the enemy of good and
all that.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

for this one as well. Take your pick ;)

Jonathan
 
> ----
> v7 --> v8
> - make sensor_ops NON global
> ---
>  drivers/iio/common/scmi_sensors/scmi_iio.c | 100 ++++++++++-----------
>  1 file changed, 50 insertions(+), 50 deletions(-)
> 
> diff --git a/drivers/iio/common/scmi_sensors/scmi_iio.c b/drivers/iio/common/scmi_sensors/scmi_iio.c
> index 872d87ca6256..8f4154d92c68 100644
> --- a/drivers/iio/common/scmi_sensors/scmi_iio.c
> +++ b/drivers/iio/common/scmi_sensors/scmi_iio.c
> @@ -22,7 +22,8 @@
>  #define SCMI_IIO_NUM_OF_AXIS 3
>  
>  struct scmi_iio_priv {
> -	struct scmi_handle *handle;
> +	const struct scmi_sensor_proto_ops *sensor_ops;
> +	struct scmi_protocol_handle *ph;
>  	const struct scmi_sensor_info *sensor_info;
>  	struct iio_dev *indio_dev;
>  	/* adding one additional channel for timestamp */
> @@ -82,7 +83,6 @@ static int scmi_iio_sensor_update_cb(struct notifier_block *nb,
>  static int scmi_iio_buffer_preenable(struct iio_dev *iio_dev)
>  {
>  	struct scmi_iio_priv *sensor = iio_priv(iio_dev);
> -	u32 sensor_id = sensor->sensor_info->id;
>  	u32 sensor_config = 0;
>  	int err;
>  
> @@ -92,27 +92,12 @@ static int scmi_iio_buffer_preenable(struct iio_dev *iio_dev)
>  
>  	sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
>  				    SCMI_SENS_CFG_SENSOR_ENABLE);
> -
> -	err = sensor->handle->notify_ops->register_event_notifier(sensor->handle,
> -			SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
> -			&sensor_id, &sensor->sensor_update_nb);
> -	if (err) {
> -		dev_err(&iio_dev->dev,
> -			"Error in registering sensor update notifier for sensor %s err %d",
> -			sensor->sensor_info->name, err);
> -		return err;
> -	}
> -
> -	err = sensor->handle->sensor_ops->config_set(sensor->handle,
> -			sensor->sensor_info->id, sensor_config);
> -	if (err) {
> -		sensor->handle->notify_ops->unregister_event_notifier(sensor->handle,
> -				SCMI_PROTOCOL_SENSOR,
> -				SCMI_EVENT_SENSOR_UPDATE, &sensor_id,
> -				&sensor->sensor_update_nb);
> +	err = sensor->sensor_ops->config_set(sensor->ph,
> +					     sensor->sensor_info->id,
> +					     sensor_config);
> +	if (err)
>  		dev_err(&iio_dev->dev, "Error in enabling sensor %s err %d",
>  			sensor->sensor_info->name, err);
> -	}
>  
>  	return err;
>  }
> @@ -120,25 +105,14 @@ static int scmi_iio_buffer_preenable(struct iio_dev *iio_dev)
>  static int scmi_iio_buffer_postdisable(struct iio_dev *iio_dev)
>  {
>  	struct scmi_iio_priv *sensor = iio_priv(iio_dev);
> -	u32 sensor_id = sensor->sensor_info->id;
>  	u32 sensor_config = 0;
>  	int err;
>  
>  	sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
>  				    SCMI_SENS_CFG_SENSOR_DISABLE);
> -
> -	err = sensor->handle->notify_ops->unregister_event_notifier(sensor->handle,
> -			SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
> -			&sensor_id, &sensor->sensor_update_nb);
> -	if (err) {
> -		dev_err(&iio_dev->dev,
> -			"Error in unregistering sensor update notifier for sensor %s err %d",
> -			sensor->sensor_info->name, err);
> -		return err;
> -	}
> -
> -	err = sensor->handle->sensor_ops->config_set(sensor->handle, sensor_id,
> -						     sensor_config);
> +	err = sensor->sensor_ops->config_set(sensor->ph,
> +					     sensor->sensor_info->id,
> +					     sensor_config);
>  	if (err) {
>  		dev_err(&iio_dev->dev,
>  			"Error in disabling sensor %s with err %d",
> @@ -161,8 +135,9 @@ static int scmi_iio_set_odr_val(struct iio_dev *iio_dev, int val, int val2)
>  	u32 sensor_config;
>  	char buf[32];
>  
> -	int err = sensor->handle->sensor_ops->config_get(sensor->handle,
> -			sensor->sensor_info->id, &sensor_config);
> +	int err = sensor->sensor_ops->config_get(sensor->ph,
> +						 sensor->sensor_info->id,
> +						 &sensor_config);
>  	if (err) {
>  		dev_err(&iio_dev->dev,
>  			"Error in getting sensor config for sensor %s err %d",
> @@ -208,8 +183,9 @@ static int scmi_iio_set_odr_val(struct iio_dev *iio_dev, int val, int val2)
>  	sensor_config |=
>  		FIELD_PREP(SCMI_SENS_CFG_ROUND_MASK, SCMI_SENS_CFG_ROUND_AUTO);
>  
> -	err = sensor->handle->sensor_ops->config_set(sensor->handle,
> -			sensor->sensor_info->id, sensor_config);
> +	err = sensor->sensor_ops->config_set(sensor->ph,
> +					     sensor->sensor_info->id,
> +					     sensor_config);
>  	if (err)
>  		dev_err(&iio_dev->dev,
>  			"Error in setting sensor update interval for sensor %s value %u err %d",
> @@ -274,8 +250,9 @@ static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val, int *val2)
>  	u32 sensor_config;
>  	int mult;
>  
> -	int err = sensor->handle->sensor_ops->config_get(sensor->handle,
> -			sensor->sensor_info->id, &sensor_config);
> +	int err = sensor->sensor_ops->config_get(sensor->ph,
> +						 sensor->sensor_info->id,
> +						 &sensor_config);
>  	if (err) {
>  		dev_err(&iio_dev->dev,
>  			"Error in getting sensor config for sensor %s err %d",
> @@ -542,15 +519,19 @@ static int scmi_iio_buffers_setup(struct iio_dev *scmi_iiodev)
>  	return 0;
>  }
>  
> -static struct iio_dev *scmi_alloc_iiodev(struct device *dev,
> -					 struct scmi_handle *handle,
> -					 const struct scmi_sensor_info *sensor_info)
> +static struct iio_dev *
> +scmi_alloc_iiodev(struct scmi_device *sdev,
> +		  const struct scmi_sensor_proto_ops *ops,
> +		  struct scmi_protocol_handle *ph,
> +		  const struct scmi_sensor_info *sensor_info)
>  {
>  	struct iio_chan_spec *iio_channels;
>  	struct scmi_iio_priv *sensor;
>  	enum iio_modifier modifier;
>  	enum iio_chan_type type;
>  	struct iio_dev *iiodev;
> +	struct device *dev = &sdev->dev;
> +	const struct scmi_handle *handle = sdev->handle;
>  	int i, ret;
>  
>  	iiodev = devm_iio_device_alloc(dev, sizeof(*sensor));
> @@ -560,7 +541,8 @@ static struct iio_dev *scmi_alloc_iiodev(struct device *dev,
>  	iiodev->modes = INDIO_DIRECT_MODE;
>  	iiodev->dev.parent = dev;
>  	sensor = iio_priv(iiodev);
> -	sensor->handle = handle;
> +	sensor->sensor_ops = ops;
> +	sensor->ph = ph;
>  	sensor->sensor_info = sensor_info;
>  	sensor->sensor_update_nb.notifier_call = scmi_iio_sensor_update_cb;
>  	sensor->indio_dev = iiodev;
> @@ -595,6 +577,17 @@ static struct iio_dev *scmi_alloc_iiodev(struct device *dev,
>  					  sensor_info->axis[i].id);
>  	}
>  
> +	ret = handle->notify_ops->devm_event_notifier_register(sdev,
> +				SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
> +				&sensor->sensor_info->id,
> +				&sensor->sensor_update_nb);
> +	if (ret) {
> +		dev_err(&iiodev->dev,
> +			"Error in registering sensor update notifier for sensor %s err %d",
> +			sensor->sensor_info->name, ret);
> +		return ERR_PTR(ret);
> +	}
> +
>  	scmi_iio_set_timestamp_channel(&iio_channels[i], i);
>  	iiodev->channels = iio_channels;
>  	return iiodev;
> @@ -604,24 +597,30 @@ static int scmi_iio_dev_probe(struct scmi_device *sdev)
>  {
>  	const struct scmi_sensor_info *sensor_info;
>  	struct scmi_handle *handle = sdev->handle;
> +	const struct scmi_sensor_proto_ops *sensor_ops;
> +	struct scmi_protocol_handle *ph;
>  	struct device *dev = &sdev->dev;
>  	struct iio_dev *scmi_iio_dev;
>  	u16 nr_sensors;
>  	int err = -ENODEV, i;
>  
> -	if (!handle || !handle->sensor_ops) {
> +	if (!handle)
> +		return -ENODEV;
> +
> +	sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
> +	if (IS_ERR(sensor_ops)) {
>  		dev_err(dev, "SCMI device has no sensor interface\n");
> -		return -EINVAL;
> +		return PTR_ERR(sensor_ops);
>  	}
>  
> -	nr_sensors = handle->sensor_ops->count_get(handle);
> +	nr_sensors = sensor_ops->count_get(ph);
>  	if (!nr_sensors) {
>  		dev_dbg(dev, "0 sensors found via SCMI bus\n");
>  		return -ENODEV;
>  	}
>  
>  	for (i = 0; i < nr_sensors; i++) {
> -		sensor_info = handle->sensor_ops->info_get(handle, i);
> +		sensor_info = sensor_ops->info_get(ph, i);
>  		if (!sensor_info) {
>  			dev_err(dev, "SCMI sensor %d has missing info\n", i);
>  			return -EINVAL;
> @@ -636,7 +635,8 @@ static int scmi_iio_dev_probe(struct scmi_device *sdev)
>  		    sensor_info->axis[0].type != RADIANS_SEC)
>  			continue;
>  
> -		scmi_iio_dev = scmi_alloc_iiodev(dev, handle, sensor_info);
> +		scmi_iio_dev = scmi_alloc_iiodev(sdev, sensor_ops, ph,
> +						 sensor_info);
>  		if (IS_ERR(scmi_iio_dev)) {
>  			dev_err(dev,
>  				"failed to allocate IIO device for sensor %s: %ld\n",