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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* COMEDI ISA DMA support functions
* Copyright (c) 2014 H Hartley Sweeten <[email protected]>
*/
#ifndef _COMEDI_ISADMA_H
#define _COMEDI_ISADMA_H
#include <linux/types.h>
struct comedi_device;
struct device;
/*
* These are used to avoid issues when <asm/dma.h> and the DMA_MODE_
* defines are not available.
*/
#define COMEDI_ISADMA_READ 0
#define COMEDI_ISADMA_WRITE 1
/**
* struct comedi_isadma_desc - cookie for ISA DMA
* @virt_addr: virtual address of buffer
* @hw_addr: hardware (bus) address of buffer
* @chan: DMA channel
* @maxsize: allocated size of buffer (in bytes)
* @size: transfer size (in bytes)
* @mode: DMA_MODE_READ or DMA_MODE_WRITE
*/
struct comedi_isadma_desc {
void *virt_addr;
dma_addr_t hw_addr;
unsigned int chan;
unsigned int maxsize;
unsigned int size;
char mode;
};
/**
* struct comedi_isadma - ISA DMA data
* @dev: device to allocate non-coherent memory for
* @desc: cookie for each DMA buffer
* @n_desc: the number of cookies
* @cur_dma: the current cookie in use
* @chan: the first DMA channel requested
* @chan2: the second DMA channel requested
*/
struct comedi_isadma {
struct device *dev;
struct comedi_isadma_desc *desc;
int n_desc;
int cur_dma;
unsigned int chan;
unsigned int chan2;
};
#if IS_ENABLED(CONFIG_ISA_DMA_API)
void comedi_isadma_program(struct comedi_isadma_desc *desc);
unsigned int comedi_isadma_disable(unsigned int dma_chan);
unsigned int comedi_isadma_disable_on_sample(unsigned int dma_chan,
unsigned int size);
unsigned int comedi_isadma_poll(struct comedi_isadma *dma);
void comedi_isadma_set_mode(struct comedi_isadma_desc *desc, char dma_dir);
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);
void comedi_isadma_free(struct comedi_isadma *dma);
#else /* !IS_ENABLED(CONFIG_ISA_DMA_API) */
static inline void comedi_isadma_program(struct comedi_isadma_desc *desc)
{
}
static inline unsigned int comedi_isadma_disable(unsigned int dma_chan)
{
return 0;
}
static inline unsigned int
comedi_isadma_disable_on_sample(unsigned int dma_chan, unsigned int size)
{
return 0;
}
static inline unsigned int comedi_isadma_poll(struct comedi_isadma *dma)
{
return 0;
}
static inline void comedi_isadma_set_mode(struct comedi_isadma_desc *desc,
char dma_dir)
{
}
static inline 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)
{
return NULL;
}
static inline void comedi_isadma_free(struct comedi_isadma *dma)
{
}
#endif /* !IS_ENABLED(CONFIG_ISA_DMA_API) */
#endif /* #ifndef _COMEDI_ISADMA_H */
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