Edit File: buffer-dma.h
/* * 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