linux/include/asm-arm/arch-pxa/dma.h
Nicolas Pitre 99532559dc [ARM] 3500/1: fix PXA27x DMA allocation priority
Patch from Nicolas Pitre

Intel PXA27x developers manual section 5.4.1.1 lists a priority
distribution for the DMA channels differently than what the code
currently assumes.  This patch fixes that.

Noticed by Simon Vogl <vogl@soft.uni-linz.ac.at>

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-05-05 22:32:24 +01:00

65 lines
1.5 KiB
C

/*
* linux/include/asm-arm/arch-pxa/dma.h
*
* Author: Nicolas Pitre
* Created: Jun 15, 2001
* Copyright: MontaVista Software, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_ARCH_DMA_H
#define __ASM_ARCH_DMA_H
/*
* Descriptor structure for PXA's DMA engine
* Note: this structure must always be aligned to a 16-byte boundary.
*/
typedef struct pxa_dma_desc {
volatile u32 ddadr; /* Points to the next descriptor + flags */
volatile u32 dsadr; /* DSADR value for the current transfer */
volatile u32 dtadr; /* DTADR value for the current transfer */
volatile u32 dcmd; /* DCMD value for the current transfer */
} pxa_dma_desc;
typedef enum {
DMA_PRIO_HIGH = 0,
DMA_PRIO_MEDIUM = 1,
DMA_PRIO_LOW = 2
} pxa_dma_prio;
#if defined(CONFIG_PXA27x)
#define PXA_DMA_CHANNELS 32
#define pxa_for_each_dma_prio(ch, prio) \
for ( \
ch = prio * 4; \
ch != (4 << prio) + 16; \
ch = (ch + 1 == (4 << prio)) ? (prio * 4 + 16) : (ch + 1) \
)
#elif defined(CONFIG_PXA25x)
#define PXA_DMA_CHANNELS 16
#define pxa_for_each_dma_prio(ch, prio) \
for (ch = prio * 4; ch != (4 << prio); ch++)
#endif
/*
* DMA registration
*/
int pxa_request_dma (char *name,
pxa_dma_prio prio,
void (*irq_handler)(int, void *, struct pt_regs *),
void *data);
void pxa_free_dma (int dma_ch);
#endif /* _ASM_ARCH_DMA_H */