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kernel/linux-rt-4.4.41/arch/mn10300/include/asm/dma.h 3.09 KB
5113f6f70   김현기   kernel add
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  /* MN10300 ISA DMA handlers and definitions
   *
   * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
   * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public Licence
   * as published by the Free Software Foundation; either version
   * 2 of the Licence, or (at your option) any later version.
   */
  #ifndef _ASM_DMA_H
  #define _ASM_DMA_H
  
  #include <linux/spinlock.h>
  #include <asm/io.h>
  #include <linux/delay.h>
  
  #undef MAX_DMA_CHANNELS		/* switch off linux/kernel/dma.c */
  #define MAX_DMA_ADDRESS		0xbfffffff
  
  extern spinlock_t dma_spin_lock;
  
  static inline unsigned long claim_dma_lock(void)
  {
  	unsigned long flags;
  	spin_lock_irqsave(&dma_spin_lock, flags);
  	return flags;
  }
  
  static inline void release_dma_lock(unsigned long flags)
  {
  	spin_unlock_irqrestore(&dma_spin_lock, flags);
  }
  
  /* enable/disable a specific DMA channel */
  static inline void enable_dma(unsigned int dmanr)
  {
  }
  
  static inline void disable_dma(unsigned int dmanr)
  {
  }
  
  /* Clear the 'DMA Pointer Flip Flop'.
   * Write 0 for LSB/MSB, 1 for MSB/LSB access.
   * Use this once to initialize the FF to a known state.
   * After that, keep track of it. :-)
   * --- In order to do that, the DMA routines below should ---
   * --- only be used while holding the DMA lock ! ---
   */
  static inline void clear_dma_ff(unsigned int dmanr)
  {
  }
  
  /* set mode (above) for a specific DMA channel */
  static inline void set_dma_mode(unsigned int dmanr, char mode)
  {
  }
  
  /* Set only the page register bits of the transfer address.
   * This is used for successive transfers when we know the contents of
   * the lower 16 bits of the DMA current address register, but a 64k boundary
   * may have been crossed.
   */
  static inline void set_dma_page(unsigned int dmanr, char pagenr)
  {
  }
  
  
  /* Set transfer address & page bits for specific DMA channel.
   * Assumes dma flipflop is clear.
   */
  static inline void set_dma_addr(unsigned int dmanr, unsigned int a)
  {
  }
  
  
  /* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for
   * a specific DMA channel.
   * You must ensure the parameters are valid.
   * NOTE: from a manual: "the number of transfers is one more
   * than the initial word count"! This is taken into account.
   * Assumes dma flip-flop is clear.
   * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7.
   */
  static inline void set_dma_count(unsigned int dmanr, unsigned int count)
  {
  }
  
  
  /* 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.
   *
   * Assumes DMA flip-flop is clear.
   */
  static inline int get_dma_residue(unsigned int dmanr)
  {
  	return 0;
  }
  
  
  /* These are in kernel/dma.c: */
  extern int request_dma(unsigned int dmanr, const char *device_id);
  extern void free_dma(unsigned int dmanr);
  
  /* From PCI */
  
  #ifdef CONFIG_PCI
  extern int isa_dma_bridge_buggy;
  #else
  #define isa_dma_bridge_buggy 	(0)
  #endif
  
  #endif /* _ASM_DMA_H */