linux/arch/arm/mach-pxa/dma.c
Linus Torvalds 0cd61b68c3 Initial blind fixup for arm for irq changes
Untested, but this should fix up the bulk of the totally mechanical
issues, and should make the actual detail fixing easier.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-06 10:59:54 -07:00

126 lines
2.7 KiB
C

/*
* linux/arch/arm/mach-pxa/dma.c
*
* PXA DMA registration and IRQ dispatching
*
* Author: Nicolas Pitre
* Created: Nov 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.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/hardware.h>
#include <asm/dma.h>
#include <asm/arch/pxa-regs.h>
static struct dma_channel {
char *name;
void (*irq_handler)(int, void *);
void *data;
} dma_channels[PXA_DMA_CHANNELS];
int pxa_request_dma (char *name, pxa_dma_prio prio,
void (*irq_handler)(int, void *),
void *data)
{
unsigned long flags;
int i, found = 0;
/* basic sanity checks */
if (!name || !irq_handler)
return -EINVAL;
local_irq_save(flags);
do {
/* try grabbing a DMA channel with the requested priority */
pxa_for_each_dma_prio (i, prio) {
if (!dma_channels[i].name) {
found = 1;
break;
}
}
/* if requested prio group is full, try a hier priority */
} while (!found && prio--);
if (found) {
DCSR(i) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
dma_channels[i].name = name;
dma_channels[i].irq_handler = irq_handler;
dma_channels[i].data = data;
} else {
printk (KERN_WARNING "No more available DMA channels for %s\n", name);
i = -ENODEV;
}
local_irq_restore(flags);
return i;
}
void pxa_free_dma (int dma_ch)
{
unsigned long flags;
if (!dma_channels[dma_ch].name) {
printk (KERN_CRIT
"%s: trying to free channel %d which is already freed\n",
__FUNCTION__, dma_ch);
return;
}
local_irq_save(flags);
DCSR(dma_ch) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
dma_channels[dma_ch].name = NULL;
local_irq_restore(flags);
}
static irqreturn_t dma_irq_handler(int irq, void *dev_id)
{
int i, dint = DINT;
for (i = 0; i < PXA_DMA_CHANNELS; i++) {
if (dint & (1 << i)) {
struct dma_channel *channel = &dma_channels[i];
if (channel->name && channel->irq_handler) {
channel->irq_handler(i, channel->data);
} else {
/*
* IRQ for an unregistered DMA channel:
* let's clear the interrupts and disable it.
*/
printk (KERN_WARNING "spurious IRQ for DMA channel %d\n", i);
DCSR(i) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
}
}
}
return IRQ_HANDLED;
}
static int __init pxa_dma_init (void)
{
int ret;
ret = request_irq (IRQ_DMA, dma_irq_handler, 0, "DMA", NULL);
if (ret)
printk (KERN_CRIT "Wow! Can't register IRQ for DMA\n");
return ret;
}
arch_initcall(pxa_dma_init);
EXPORT_SYMBOL(pxa_request_dma);
EXPORT_SYMBOL(pxa_free_dma);