diff options
Diffstat (limited to 'include/linux/iio')
| -rw-r--r-- | include/linux/iio/buffer-dma.h | 20 | ||||
| -rw-r--r-- | include/linux/iio/buffer_impl.h | 8 | ||||
| -rw-r--r-- | include/linux/iio/frequency/ad9523.h | 2 | ||||
| -rw-r--r-- | include/linux/iio/iio.h | 139 |
4 files changed, 145 insertions, 24 deletions
diff --git a/include/linux/iio/buffer-dma.h b/include/linux/iio/buffer-dma.h index 4f33e6a39797..ef8687a88b73 100644 --- a/include/linux/iio/buffer-dma.h +++ b/include/linux/iio/buffer-dma.h @@ -119,7 +119,12 @@ struct iio_dma_buffer_queue { struct device *dev; const struct iio_dma_buffer_ops *ops; + /* + * A mutex to protect accessing, configuring (eg: enqueuing DMA blocks) + * and do file IO on struct iio_dma_buffer_queue objects. + */ struct mutex lock; + /* A spin lock to protect adding/removing blocks to the queue list */ spinlock_t list_lock; struct list_head incoming; @@ -136,20 +141,19 @@ struct iio_dma_buffer_queue { */ struct iio_dma_buffer_ops { int (*submit)(struct iio_dma_buffer_queue *queue, - struct iio_dma_buffer_block *block); + struct iio_dma_buffer_block *block); void (*abort)(struct iio_dma_buffer_queue *queue); }; void iio_dma_buffer_block_done(struct iio_dma_buffer_block *block); void iio_dma_buffer_block_list_abort(struct iio_dma_buffer_queue *queue, - struct list_head *list); + struct list_head *list); -int iio_dma_buffer_enable(struct iio_buffer *buffer, - struct iio_dev *indio_dev); +int iio_dma_buffer_enable(struct iio_buffer *buffer, struct iio_dev *indio_dev); int iio_dma_buffer_disable(struct iio_buffer *buffer, - struct iio_dev *indio_dev); + struct iio_dev *indio_dev); int iio_dma_buffer_read(struct iio_buffer *buffer, size_t n, - char __user *user_buffer); + char __user *user_buffer); int iio_dma_buffer_write(struct iio_buffer *buffer, size_t n, const char __user *user_buffer); size_t iio_dma_buffer_usage(struct iio_buffer *buffer); @@ -157,8 +161,8 @@ int iio_dma_buffer_set_bytes_per_datum(struct iio_buffer *buffer, size_t bpd); int iio_dma_buffer_set_length(struct iio_buffer *buffer, unsigned int length); int iio_dma_buffer_request_update(struct iio_buffer *buffer); -int iio_dma_buffer_init(struct iio_dma_buffer_queue *queue, - struct device *dma_dev, const struct iio_dma_buffer_ops *ops); +void iio_dma_buffer_init(struct iio_dma_buffer_queue *queue, struct device *dev, + const struct iio_dma_buffer_ops *ops); void iio_dma_buffer_exit(struct iio_dma_buffer_queue *queue); void iio_dma_buffer_release(struct iio_dma_buffer_queue *queue); diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h index c0b0e0992a85..9442c165561a 100644 --- a/include/linux/iio/buffer_impl.h +++ b/include/linux/iio/buffer_impl.h @@ -113,10 +113,10 @@ struct iio_buffer { /** @flags: File ops flags including busy flag. */ unsigned long flags; - /** @bytes_per_datum: Size of individual datum including timestamp. */ + /** @bytes_per_datum: Size of individual datum including timestamp. */ size_t bytes_per_datum; - /* @direction: Direction of the data stream (in/out). */ + /** @direction: Direction of the data stream (in/out). */ enum iio_buffer_direction direction; /** @@ -178,7 +178,9 @@ struct iio_buffer { * @insert_buffer: buffer to insert * @remove_buffer: buffer_to_remove * - * Note this will tear down the all buffering and build it up again + * Note this will tear down all the buffering and build it up again + * + * Returns: 0 on success or -errno on error */ int iio_update_buffers(struct iio_dev *indio_dev, struct iio_buffer *insert_buffer, diff --git a/include/linux/iio/frequency/ad9523.h b/include/linux/iio/frequency/ad9523.h index ff22a0ac15f5..236437a226b2 100644 --- a/include/linux/iio/frequency/ad9523.h +++ b/include/linux/iio/frequency/ad9523.h @@ -45,7 +45,7 @@ enum ref_sel_mode { * @output_dis: Disables, powers down the entire channel. * @driver_mode: Output driver mode (logic level family). * @divider_phase: Divider initial phase after a SYNC. Range 0..63 - LSB = 1/2 of a period of the divider input clock. + * LSB = 1/2 of a period of the divider input clock. * @channel_divider: 10-bit channel divider. * @extended_name: Optional descriptive channel name. */ diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index 872ebdf0dd77..a9ecff191bd9 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -10,6 +10,7 @@ #include <linux/align.h> #include <linux/device.h> #include <linux/cdev.h> +#include <linux/cleanup.h> #include <linux/compiler_types.h> #include <linux/minmax.h> #include <linux/slab.h> @@ -661,34 +662,148 @@ void iio_device_unregister(struct iio_dev *indio_dev); int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev, struct module *this_mod); int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp); -bool __iio_device_claim_direct(struct iio_dev *indio_dev); -void __iio_device_release_direct(struct iio_dev *indio_dev); + +void __iio_dev_mode_lock(struct iio_dev *indio_dev) __acquires(indio_dev); +void __iio_dev_mode_unlock(struct iio_dev *indio_dev) __releases(indio_dev); /* * Helper functions that allow claim and release of direct mode * in a fashion that doesn't generate many false positives from sparse. * Note this must remain static inline in the header so that sparse - * can see the __acquire() marking. Revisit when sparse supports - * __cond_acquires() + * can see the __acquires() and __releases() annotations. + */ + +/** + * iio_device_claim_direct() - 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() is called. + * + * Use with iio_device_release_direct(). + * + * Returns: true on success, false on failure. */ static inline bool iio_device_claim_direct(struct iio_dev *indio_dev) { - if (!__iio_device_claim_direct(indio_dev)) - return false; + __iio_dev_mode_lock(indio_dev); - __acquire(iio_dev); + if (iio_buffer_enabled(indio_dev)) { + __iio_dev_mode_unlock(indio_dev); + return false; + } return true; } -static inline void iio_device_release_direct(struct iio_dev *indio_dev) +/** + * iio_device_release_direct() - 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(). + */ +#define iio_device_release_direct(indio_dev) __iio_dev_mode_unlock(indio_dev) + +/** + * iio_device_try_claim_buffer_mode() - Keep device in buffer mode + * @indio_dev: the iio_dev associated with the device + * + * If the device is in buffer mode it is guaranteed to stay + * that way until iio_device_release_buffer_mode() is called. + * + * Use with iio_device_release_buffer_mode(). + * + * Returns: true on success, false on failure. + */ +static inline bool iio_device_try_claim_buffer_mode(struct iio_dev *indio_dev) { - __iio_device_release_direct(indio_dev); - __release(indio_dev); + __iio_dev_mode_lock(indio_dev); + + if (!iio_buffer_enabled(indio_dev)) { + __iio_dev_mode_unlock(indio_dev); + return false; + } + + return true; } -int iio_device_claim_buffer_mode(struct iio_dev *indio_dev); -void iio_device_release_buffer_mode(struct iio_dev *indio_dev); +/** + * iio_device_release_buffer_mode() - releases claim on buffer mode + * @indio_dev: the iio_dev associated with the device + * + * Release the claim. Device is no longer guaranteed to stay + * in buffer mode. + * + * Use with iio_device_try_claim_buffer_mode(). + */ +#define iio_device_release_buffer_mode(indio_dev) __iio_dev_mode_unlock(indio_dev) + +/* + * These classes are not meant to be used directly by drivers (hence the + * __priv__ prefix). Instead, documented wrapper macros are provided below to + * enforce the use of ACQUIRE() or guard() semantics and avoid the problematic + * scoped guard variants. + */ +DEFINE_GUARD(__priv__iio_dev_mode_lock, struct iio_dev *, + __iio_dev_mode_lock(_T), __iio_dev_mode_unlock(_T)); +DEFINE_GUARD_COND(__priv__iio_dev_mode_lock, _try_direct, + iio_device_claim_direct(_T)); + +/** + * IIO_DEV_ACQUIRE_DIRECT_MODE() - Tries to acquire the direct mode lock with + * automatic release + * @dev: IIO device instance + * @claim: Variable identifier to store acquire result + * + * Tries to acquire the direct mode lock with cleanup ACQUIRE() semantics and + * automatically releases it at the end of the scope. It most be always paired + * with IIO_DEV_ACQUIRE_ERR(), for example (notice the scope braces):: + * + * switch() { + * case IIO_CHAN_INFO_RAW: { + * IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim); + * if (IIO_DEV_ACQUIRE_FAILED(claim)) + * return -EBUSY; + * + * ... + * } + * case IIO_CHAN_INFO_SCALE: + * ... + * ... + * } + * + * Context: Can sleep + */ +#define IIO_DEV_ACQUIRE_DIRECT_MODE(dev, claim) \ + ACQUIRE(__priv__iio_dev_mode_lock_try_direct, claim)(dev) + +/** + * IIO_DEV_ACQUIRE_FAILED() - ACQUIRE_ERR() wrapper + * @claim: The claim variable passed to IIO_DEV_ACQUIRE_*_MODE() + * + * Return: true if failed to acquire the mode, otherwise false. + */ +#define IIO_DEV_ACQUIRE_FAILED(claim) \ + ACQUIRE_ERR(__priv__iio_dev_mode_lock_try_direct, &(claim)) + +/** + * IIO_DEV_GUARD_CURRENT_MODE() - Acquires the mode lock with automatic release + * @dev: IIO device instance + * + * Acquires the mode lock with cleanup guard() semantics. It is usually paired + * with iio_buffer_enabled(). + * + * This should *not* be used to protect internal driver state and it's use in + * general is *strongly* discouraged. Use any of the IIO_DEV_ACQUIRE_*_MODE() + * variants. + * + * Context: Can sleep + */ +#define IIO_DEV_GUARD_CURRENT_MODE(dev) \ + guard(__priv__iio_dev_mode_lock)(dev) extern const struct bus_type iio_bus_type; |