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