linux/drivers/comedi/drivers/comedi_isadma.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * COMEDI ISA DMA support functions
 * Copyright (c) 2014 H Hartley Sweeten <[email protected]>
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/isa-dma.h>
#include <linux/comedi/comedidev.h>
#include <linux/comedi/comedi_isadma.h>

/**
 * comedi_isadma_program - program and enable an ISA DMA transfer
 * @desc:	the ISA DMA cookie to program and enable
 */
void comedi_isadma_program(struct comedi_isadma_desc *desc)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * comedi_isadma_disable - disable the ISA DMA channel
 * @dma_chan:	the DMA channel to disable
 *
 * Returns the residue (remaining bytes) left in the DMA transfer.
 */
unsigned int comedi_isadma_disable(unsigned int dma_chan)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * comedi_isadma_disable_on_sample - disable the ISA DMA channel
 * @dma_chan:	the DMA channel to disable
 * @size:	the sample size (in bytes)
 *
 * Returns the residue (remaining bytes) left in the DMA transfer.
 */
unsigned int comedi_isadma_disable_on_sample(unsigned int dma_chan,
					     unsigned int size)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * comedi_isadma_poll - poll the current DMA transfer
 * @dma:	the ISA DMA to poll
 *
 * Returns the position (in bytes) of the current DMA transfer.
 */
unsigned int comedi_isadma_poll(struct comedi_isadma *dma)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * comedi_isadma_set_mode - set the ISA DMA transfer direction
 * @desc:	the ISA DMA cookie to set
 * @dma_dir:	the DMA direction
 */
void comedi_isadma_set_mode(struct comedi_isadma_desc *desc, char dma_dir)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * comedi_isadma_alloc - allocate and initialize the ISA DMA
 * @dev:	comedi_device struct
 * @n_desc:	the number of cookies to allocate
 * @dma_chan1:	DMA channel for the first cookie
 * @dma_chan2:	DMA channel for the second cookie
 * @maxsize:	the size of the buffer to allocate for each cookie
 * @dma_dir:	the DMA direction
 *
 * Returns the allocated and initialized ISA DMA or NULL if anything fails.
 */
struct comedi_isadma *comedi_isadma_alloc(struct comedi_device *dev,
					  int n_desc, unsigned int dma_chan1,
					  unsigned int dma_chan2,
					  unsigned int maxsize, char dma_dir)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * comedi_isadma_free - free the ISA DMA
 * @dma:	the ISA DMA to free
 */
void comedi_isadma_free(struct comedi_isadma *dma)
{ … }
EXPORT_SYMBOL_GPL(…);

static int __init comedi_isadma_init(void)
{ … }
module_init(…) …;

static void __exit comedi_isadma_exit(void)
{ … }
module_exit(comedi_isadma_exit);

MODULE_AUTHOR(…) …;
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;