119 строки
3.1 KiB
C
119 строки
3.1 KiB
C
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/* MN10300 ISA DMA handlers and definitions
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*
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* Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public Licence
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* as published by the Free Software Foundation; either version
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* 2 of the Licence, or (at your option) any later version.
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*/
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#ifndef _ASM_DMA_H
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#define _ASM_DMA_H
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#include <asm/system.h>
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#include <linux/spinlock.h>
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#include <asm/io.h>
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#include <linux/delay.h>
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#undef MAX_DMA_CHANNELS /* switch off linux/kernel/dma.c */
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#define MAX_DMA_ADDRESS 0xbfffffff
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extern 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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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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spin_unlock_irqrestore(&dma_spin_lock, flags);
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}
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/* enable/disable a specific DMA channel */
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static inline void enable_dma(unsigned int dmanr)
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{
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}
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static inline void disable_dma(unsigned int dmanr)
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{
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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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* Use this once to initialize the FF to a known state.
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* After that, keep track of it. :-)
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* --- In order to do that, the DMA routines below should ---
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* --- only be used while holding the DMA lock ! ---
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*/
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static inline void clear_dma_ff(unsigned int dmanr)
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{
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}
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/* set mode (above) for a specific DMA channel */
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static inline void set_dma_mode(unsigned int dmanr, char mode)
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{
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}
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/* Set only the page register bits of the transfer address.
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* This is used for successive transfers when we know the contents of
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* the lower 16 bits of the DMA current address register, but a 64k boundary
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* may have been crossed.
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*/
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static inline void set_dma_page(unsigned int dmanr, char pagenr)
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{
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}
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/* Set transfer address & page bits for specific DMA channel.
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* Assumes dma flipflop is clear.
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*/
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static inline void set_dma_addr(unsigned int dmanr, unsigned int a)
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{
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}
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/* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for
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* a specific DMA channel.
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* You must ensure the parameters are valid.
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* NOTE: from a manual: "the number of transfers is one more
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* than the initial word count"! This is taken into account.
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* Assumes dma flip-flop is clear.
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* NOTE 2: "count" represents _bytes_ and must be even for channels 5-7.
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*/
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static inline void set_dma_count(unsigned int dmanr, unsigned int count)
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{
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}
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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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* Assumes DMA flip-flop is clear.
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*/
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static inline int get_dma_residue(unsigned int dmanr)
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{
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return 0;
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}
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/* These are in kernel/dma.c: */
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extern int request_dma(unsigned int dmanr, const char *device_id);
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extern void free_dma(unsigned int dmanr);
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/* From PCI */
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#ifdef CONFIG_PCI
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extern int isa_dma_bridge_buggy;
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#else
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#define isa_dma_bridge_buggy (0)
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#endif
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#endif /* _ASM_DMA_H */
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