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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_ARM_DMA_H
#define __ASM_ARM_DMA_H
/*
* This is the maximum virtual address which can be DMA'd from.
*/
#ifndef CONFIG_ZONE_DMA
#define MAX_DMA_ADDRESS 0xffffffffUL
#else
#define MAX_DMA_ADDRESS ({ \
extern phys_addr_t arm_dma_zone_size; \
arm_dma_zone_size && arm_dma_zone_size < (0x100000000ULL - PAGE_OFFSET) ? \
(PAGE_OFFSET + arm_dma_zone_size) : 0xffffffffUL; })
extern phys_addr_t arm_dma_limit;
#define ARCH_LOW_ADDRESS_LIMIT arm_dma_limit
#endif
#ifdef CONFIG_ISA_DMA_API
/*
* This is used to support drivers written for the x86 ISA DMA API.
* It should not be re-used except for that purpose.
*/
#include <linux/spinlock.h>
#include <linux/scatterlist.h>
#include <mach/isa-dma.h>
/*
* The DMA modes reflect the settings for the ISA DMA controller
*/
#define DMA_MODE_MASK 0xcc
#define DMA_MODE_READ 0x44
#define DMA_MODE_WRITE 0x48
#define DMA_MODE_CASCADE 0xc0
#define DMA_AUTOINIT 0x10
extern raw_spinlock_t dma_spin_lock;
static inline unsigned long claim_dma_lock(void)
{
unsigned long flags;
raw_spin_lock_irqsave(&dma_spin_lock, flags);
return flags;
}
static inline void release_dma_lock(unsigned long flags)
{
raw_spin_unlock_irqrestore(&dma_spin_lock, flags);
}
/* Clear the 'DMA Pointer Flip Flop'.
* Write 0 for LSB/MSB, 1 for MSB/LSB access.
*/
#define clear_dma_ff(chan)
/* Set only the page register bits of the transfer address.
*
* NOTE: This is an architecture specific function, and should
* be hidden from the drivers
*/
extern void set_dma_page(unsigned int chan, char pagenr);
/* Request a DMA channel
*
* Some architectures may need to do allocate an interrupt
*/
extern int request_dma(unsigned int chan, const char * device_id);
/* Free a DMA channel
*
* Some architectures may need to do free an interrupt
*/
extern void free_dma(unsigned int chan);
/* Enable DMA for this channel
*
* On some architectures, this may have other side effects like
* enabling an interrupt and setting the DMA registers.
*/
extern void enable_dma(unsigned int chan);
/* Disable DMA for this channel
*
* On some architectures, this may have other side effects like
* disabling an interrupt or whatever.
*/
extern void disable_dma(unsigned int chan);
/* Test whether the specified channel has an active DMA transfer
*/
extern int dma_channel_active(unsigned int chan);
/* Set the DMA scatter gather list for this channel
*
* This should not be called if a DMA channel is enabled,
* especially since some DMA architectures don't update the
* DMA address immediately, but defer it to the enable_dma().
*/
extern void set_dma_sg(unsigned int chan, struct scatterlist *sg, int nr_sg);
/* Set the DMA address for this channel
*
* This should not be called if a DMA channel is enabled,
* especially since some DMA architectures don't update the
* DMA address immediately, but defer it to the enable_dma().
*/
extern void __set_dma_addr(unsigned int chan, void *addr);
#define set_dma_addr(chan, addr) \
__set_dma_addr(chan, (void *)isa_bus_to_virt(addr))
/* Set the DMA byte count for this channel
*
* This should not be called if a DMA channel is enabled,
* especially since some DMA architectures don't update the
* DMA count immediately, but defer it to the enable_dma().
*/
extern void set_dma_count(unsigned int chan, unsigned long count);
/* Set the transfer direction for this channel
*
* This should not be called if a DMA channel is enabled,
* especially since some DMA architectures don't update the
* DMA transfer direction immediately, but defer it to the
* enable_dma().
*/
extern void set_dma_mode(unsigned int chan, unsigned int mode);
/* Set the transfer speed for this channel
*/
extern void set_dma_speed(unsigned int chan, int cycle_ns);
/* Get DMA residue count. After a DMA transfer, this
* should return zero. Reading this while a DMA transfer is
* still in progress will return unpredictable results.
* If called before the channel has been used, it may return 1.
* Otherwise, it returns the number of _bytes_ left to transfer.
*/
extern int get_dma_residue(unsigned int chan);
#ifndef NO_DMA
#define NO_DMA 255
#endif
#endif /* CONFIG_ISA_DMA_API */
#endif /* __ASM_ARM_DMA_H */
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