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Diffstat (limited to 'include/linux/iio/buffer-dma.h')
| -rw-r--r-- | include/linux/iio/buffer-dma.h | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/include/linux/iio/buffer-dma.h b/include/linux/iio/buffer-dma.h new file mode 100644 index 000000000..767467d88 --- /dev/null +++ b/include/linux/iio/buffer-dma.h @@ -0,0 +1,152 @@ +/* + * Copyright 2013-2015 Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * Licensed under the GPL-2. + */ + +#ifndef __INDUSTRIALIO_DMA_BUFFER_H__ +#define __INDUSTRIALIO_DMA_BUFFER_H__ + +#include <linux/list.h> +#include <linux/kref.h> +#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/iio/buffer.h> + +struct iio_dma_buffer_queue; +struct iio_dma_buffer_ops; +struct device; + +struct iio_buffer_block { + u32 size; + u32 bytes_used; +}; + +/** + * enum iio_block_state - State of a struct iio_dma_buffer_block + * @IIO_BLOCK_STATE_DEQUEUED: Block is not queued + * @IIO_BLOCK_STATE_QUEUED: Block is on the incoming queue + * @IIO_BLOCK_STATE_ACTIVE: Block is currently being processed by the DMA + * @IIO_BLOCK_STATE_DONE: Block is on the outgoing queue + * @IIO_BLOCK_STATE_DEAD: Block has been marked as to be freed + */ +enum iio_block_state { + IIO_BLOCK_STATE_DEQUEUED, + IIO_BLOCK_STATE_QUEUED, + IIO_BLOCK_STATE_ACTIVE, + IIO_BLOCK_STATE_DONE, + IIO_BLOCK_STATE_DEAD, +}; + +/** + * struct iio_dma_buffer_block - IIO buffer block + * @head: List head + * @size: Total size of the block in bytes + * @bytes_used: Number of bytes that contain valid data + * @vaddr: Virutal address of the blocks memory + * @phys_addr: Physical address of the blocks memory + * @queue: Parent DMA buffer queue + * @kref: kref used to manage the lifetime of block + * @state: Current state of the block + */ +struct iio_dma_buffer_block { + /* May only be accessed by the owner of the block */ + struct list_head head; + size_t bytes_used; + + /* + * Set during allocation, constant thereafter. May be accessed read-only + * by anybody holding a reference to the block. + */ + void *vaddr; + dma_addr_t phys_addr; + size_t size; + struct iio_dma_buffer_queue *queue; + + /* Must not be accessed outside the core. */ + struct kref kref; + /* + * Must not be accessed outside the core. Access needs to hold + * queue->list_lock if the block is not owned by the core. + */ + enum iio_block_state state; +}; + +/** + * struct iio_dma_buffer_queue_fileio - FileIO state for the DMA buffer + * @blocks: Buffer blocks used for fileio + * @active_block: Block being used in read() + * @pos: Read offset in the active block + * @block_size: Size of each block + */ +struct iio_dma_buffer_queue_fileio { + struct iio_dma_buffer_block *blocks[2]; + struct iio_dma_buffer_block *active_block; + size_t pos; + size_t block_size; +}; + +/** + * struct iio_dma_buffer_queue - DMA buffer base structure + * @buffer: IIO buffer base structure + * @dev: Parent device + * @ops: DMA buffer callbacks + * @lock: Protects the incoming list, active and the fields in the fileio + * substruct + * @list_lock: Protects lists that contain blocks which can be modified in + * atomic context as well as blocks on those lists. This is the outgoing queue + * list and typically also a list of active blocks in the part that handles + * the DMA controller + * @incoming: List of buffers on the incoming queue + * @outgoing: List of buffers on the outgoing queue + * @active: Whether the buffer is currently active + * @fileio: FileIO state + */ +struct iio_dma_buffer_queue { + struct iio_buffer buffer; + struct device *dev; + const struct iio_dma_buffer_ops *ops; + + struct mutex lock; + spinlock_t list_lock; + struct list_head incoming; + struct list_head outgoing; + + bool active; + + struct iio_dma_buffer_queue_fileio fileio; +}; + +/** + * struct iio_dma_buffer_ops - DMA buffer callback operations + * @submit: Called when a block is submitted to the DMA controller + * @abort: Should abort all pending transfers + */ +struct iio_dma_buffer_ops { + int (*submit)(struct iio_dma_buffer_queue *queue, + 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); + +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); +int iio_dma_buffer_read(struct iio_buffer *buffer, size_t n, + char __user *user_buffer); +size_t iio_dma_buffer_data_available(struct iio_buffer *buffer); +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, 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_exit(struct iio_dma_buffer_queue *queue); +void iio_dma_buffer_release(struct iio_dma_buffer_queue *queue); + +#endif |