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Commit c8cdf708 authored by Matt Ranostay's avatar Matt Ranostay Committed by Jonathan Cameron
Browse files

iio: trigger: allow immutable triggers to be assigned 



There are times when an assigned trigger to a device shouldn't ever
change after intialization.

Examples of this being used is when an provider device has a trigger
that is assigned to an ADC, which uses it populate data into a callback
buffer.

Signed-off-by: default avatarMatt Ranostay <matt@ranostay.consulting>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent a5c8b11a

drivers/iio/industrialio-trigger.c

+20 −0
Original line number Diff line number Diff line
@@ -119,6 +119,22 @@ void iio_trigger_unregister(struct iio_trigger *trig_info) 
}

EXPORT_SYMBOL(iio_trigger_unregister);



int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig)

{

	if (!indio_dev || !trig)

		return -EINVAL;



	mutex_lock(&indio_dev->mlock);

	WARN_ON(indio_dev->trig_readonly);



	indio_dev->trig = iio_trigger_get(trig);

	indio_dev->trig_readonly = true;

	mutex_unlock(&indio_dev->mlock);



	return 0;

}

EXPORT_SYMBOL(iio_trigger_set_immutable);



/* Search for trigger by name, assuming iio_trigger_list_lock held */

static struct iio_trigger *__iio_trigger_find_by_name(const char *name)

{
@@ -384,6 +400,10 @@ static ssize_t iio_trigger_write_current(struct device *dev, 
		mutex_unlock(&indio_dev->mlock);

		return -EBUSY;

	}

	if (indio_dev->trig_readonly) {

		mutex_unlock(&indio_dev->mlock);

		return -EPERM;

	}

	mutex_unlock(&indio_dev->mlock);



	trig = iio_trigger_find_by_name(buf, len);

include/linux/iio/iio.h

+2 −0
Original line number Diff line number Diff line
@@ -483,6 +483,7 @@ struct iio_buffer_setup_ops { 
 * @scan_timestamp:	[INTERN] set if any buffers have requested timestamp

 * @scan_index_timestamp:[INTERN] cache of the index to the timestamp

 * @trig:		[INTERN] current device trigger (buffer modes)

 * @trig_readonly	[INTERN] mark the current trigger immutable

 * @pollfunc:		[DRIVER] function run on trigger being received

 * @pollfunc_event:	[DRIVER] function run on events trigger being received

 * @channels:		[DRIVER] channel specification structure table
@@ -523,6 +524,7 @@ struct iio_dev { 
	bool				scan_timestamp;

	unsigned			scan_index_timestamp;

	struct iio_trigger		*trig;

	bool				trig_readonly;

	struct iio_poll_func		*pollfunc;

	struct iio_poll_func		*pollfunc_event;

include/linux/iio/trigger.h

+9 −0
Original line number Diff line number Diff line
@@ -131,6 +131,15 @@ int iio_trigger_register(struct iio_trigger *trig_info); 
 **/

void iio_trigger_unregister(struct iio_trigger *trig_info);



/**

 * iio_trigger_set_immutable() - set an immutable trigger on destination

 *

 * @indio_dev - IIO device structure containing the device

 * @trig - trigger to assign to device

 *

 **/

int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig);



/**

 * iio_trigger_poll() - called on a trigger occurring

 * @trig:	trigger which occurred