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| author | Matt Ranostay <mranostay@gmail.com> | 2016-09-03 08:36:15 +0200 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2016-09-03 16:31:55 +0200 |
| commit | c8cdf70890d89c07c9e890b103106d58999f0ce4 (patch) | |
| tree | c96f5fa74ac061a3151b1099119a584c55a18a85 /drivers/iio | |
| parent | iio: sx9500: add final devicetree support (diff) | |
| download | linux-c8cdf70890d89c07c9e890b103106d58999f0ce4.tar.xz linux-c8cdf70890d89c07c9e890b103106d58999f0ce4.zip | |
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>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/industrialio-trigger.c | 20 |
1 files changed, 20 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); |