diff options
| -rw-r--r-- | drivers/iio/industrialio-core.c | 39 | ||||
| -rw-r--r-- | include/linux/iio/iio.h | 2 |
2 files changed, 41 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c index 70cb7eb0a75c..2e768bc99f05 100644 --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -25,6 +25,7 @@ #include <linux/slab.h> #include <linux/anon_inodes.h> #include <linux/debugfs.h> +#include <linux/mutex.h> #include <linux/iio/iio.h> #include "iio_core.h" #include "iio_core_trigger.h" @@ -1375,6 +1376,44 @@ void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev) } EXPORT_SYMBOL_GPL(devm_iio_device_unregister); +/** + * iio_device_claim_direct_mode - Keep device in direct mode + * @indio_dev: the iio_dev associated with the device + * + * If the device is in direct mode it is guaranteed to stay + * that way until iio_device_release_direct_mode() is called. + * + * Use with iio_device_release_direct_mode() + * + * Returns: 0 on success, -EBUSY on failure + */ +int iio_device_claim_direct_mode(struct iio_dev *indio_dev) +{ + mutex_lock(&indio_dev->mlock); + + if (iio_buffer_enabled(indio_dev)) { + mutex_unlock(&indio_dev->mlock); + return -EBUSY; + } + return 0; +} +EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode); + +/** + * iio_device_release_direct_mode - releases claim on direct mode + * @indio_dev: the iio_dev associated with the device + * + * Release the claim. Device is no longer guaranteed to stay + * in direct mode. + * + * Use with iio_device_claim_direct_mode() + */ +void iio_device_release_direct_mode(struct iio_dev *indio_dev) +{ + mutex_unlock(&indio_dev->mlock); +} +EXPORT_SYMBOL_GPL(iio_device_release_direct_mode); + subsys_initcall(iio_init); module_exit(iio_exit); diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index b2b16772c651..0b2773ada0ba 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -527,6 +527,8 @@ void iio_device_unregister(struct iio_dev *indio_dev); int devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev); void devm_iio_device_unregister(struct device *dev, struct iio_dev *indio_dev); int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp); +int iio_device_claim_direct_mode(struct iio_dev *indio_dev); +void iio_device_release_direct_mode(struct iio_dev *indio_dev); extern struct bus_type iio_bus_type; |