include/linux/comedi/comedi_isadma.h

Source file repositories/reference/linux-study-clean/include/linux/comedi/comedi_isadma.h

File Facts

System
Linux kernel
Corpus path
include/linux/comedi/comedi_isadma.h
Extension
.h
Size
2857 bytes
Lines
115
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

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;
	int n_desc;
	int cur_dma;
	unsigned int chan;
	unsigned int chan2;
	struct comedi_isadma_desc desc[] __counted_by(n_desc);
};

#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 */

Annotation

Implementation Notes