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