path: root/arch/arm/mach-pnx4008/dma.c

/*
 *  linux/arch/arm/mach-pnx4008/dma.c
 *
 *  PNX4008 DMA registration and IRQ dispatching
 *
 *  Author:	Vitaly Wool
 *  Copyright:	MontaVista Software Inc. (c) 2005
 *
 *  Based on the code from Nicolas Pitre
 *
 *  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 <linux/err.h>
#include <linux/dma-mapping.h>
#include <linux/clk.h>

#include <asm/system.h>
#include <mach/hardware.h>
#include <asm/dma.h>
#include <asm/dma-mapping.h>
#include <asm/io.h>
#include <asm/mach/dma.h>
#include <mach/clock.h>

static struct dma_channel {
	char *name;
	void (*irq_handler) (int, int, void *);
	void *data;
	struct pnx4008_dma_ll *ll;
	u32 ll_dma;
	void *target_addr;
	int target_id;
} dma_channels[MAX_DMA_CHANNELS];

static struct ll_pool {
	void *vaddr;
	void *cur;
	dma_addr_t dma_addr;
	int count;
} ll_pool;

static DEFINE_SPINLOCK(ll_lock);

struct pnx4008_dma_ll *pnx4008_alloc_ll_entry(dma_addr_t * ll_dma)
{
	struct pnx4008_dma_ll *ll = NULL;
	unsigned long flags;

	spin_lock_irqsave(&ll_lock, flags);
	if (ll_pool.count > 4) { /* can give one more */
		ll = *(struct pnx4008_dma_ll **) ll_pool.cur;
		*ll_dma = ll_pool.dma_addr + ((void *)ll - ll_pool.vaddr);
		*(void **)ll_pool.cur = **(void ***)ll_pool.cur;
		memset(ll, 0, sizeof(*ll));
		ll_pool.count--;
	}
	spin_unlock_irqrestore(&ll_lock, flags);

	return ll;
}

EXPORT_SYMBOL_GPL(pnx4008_alloc_ll_entry);

void pnx4008_free_ll_entry(struct pnx4008_dma_ll * ll, dma_addr_t ll_dma)
{
	unsigned long flags;

	if (ll) {
		if ((unsigned long)((long)ll - (long)ll_pool.vaddr) > 0x4000) {
			printk(KERN_ERR "Trying to free entry not allocated by DMA\n");
			BUG();
		}

		if (ll->flags & DMA_BUFFER_ALLOCATED)
			ll->free(ll->alloc_data);

		spin_lock_irqsave(&ll_lock, flags);
		*(long *)ll = *(long *)ll_pool.cur;
		*(long *)ll_pool.cur = (long)ll;
		ll_pool.count++;
		spin_unlock_irqrestore(&ll_lock, flags);
	}
}

EXPORT_SYMBOL_GPL(pnx4008_free_ll_entry);

void pnx4008_free_ll(u32 ll_dma, struct pnx4008_dma_ll * ll)
{
	struct pnx4008_dma_ll *ptr;
	u32 dma;

	while (ll) {
		dma = ll->next_dma;
		ptr = ll->next;
		pnx4008_free_ll_entry(ll, ll_dma);

		ll_dma = dma;
		ll = ptr;
	}
}

EXPORT_SYMBOL_GPL(pnx4008_free_ll);

static int dma_channels_requested = 0;

static inline void dma_increment_usage(void)
{
	if (!dma_channels_requested++) {
		struct clk *clk = clk_get(0, "dma_ck");
		if (!IS_ERR(clk)) {
			clk_set_rate(clk, 1);
			clk_put(clk);
		}
		pnx4008_config_dma(-1, -1, 1);
	}
}
static inline void dma_decrement_usage(void)
{
	if (!--dma_channels_requested) {
		struct clk *clk