diff options
| author | Matt Ranostay | 2016-09-02 23:36:15 -0700 |
|---|---|---|
| committer | Jonathan Cameron | 2016-09-03 15:31:55 +0100 |
| commit | c8cdf70890d89c07c9e890b103106d58999f0ce4 (patch) | |
| tree | c96f5fa74ac061a3151b1099119a584c55a18a85 | |
| parent | a5c8b11a361065db028721c62aa880bfe0736aa6 (diff) | |
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: Matt Ranostay <matt@ranostay.consulting>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
| -rw-r--r-- | drivers/iio/industrialio-trigger.c | 20 | ||||
| -rw-r--r-- | include/linux/iio/iio.h | 2 | ||||
| -rw-r--r-- | include/linux/iio/trigger.h | 9 |
3 files changed, 31 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c index 7ad82fdd3e5b..3dde81e57e97 100644 --- a/drivers/iio/industrialio-trigger.c +++ b/drivers/iio/industrialio-trigger.c @@ -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); diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 854e2dad1e0d..786952cd509f 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -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; diff --git a/include/linux/iio/trigger.h b/include/linux/iio/trigger.h index 1c9e028e0d4a..a122bdd4076c 100644 --- a/include/linux/iio/trigger.h +++ b/include/linux/iio/trigger.h @@ -132,6 +132,15 @@ 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 * |