/*
 * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
 * Copyright (C) 2009 Wind River Systems Inc
 *  Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
 *
 * Based on DMA code from MIPS.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/cache.h>
#include <asm/cacheflush.h>

void arch_sync_dma_for_device(phys_addr_t paddr, size_t size,
                enum dma_data_direction dir)
{
        void *vaddr = phys_to_virt(paddr);

        switch (dir) {
        case DMA_FROM_DEVICE:
                invalidate_dcache_range((unsigned long)vaddr,
                        (unsigned long)(vaddr + size));
                break;
        case DMA_TO_DEVICE:
                /*
                 * We just need to flush the caches here , but Nios2 flush
                 * instruction will do both writeback and invalidate.
                 */
        case DMA_BIDIRECTIONAL: /* flush and invalidate */
                flush_dcache_range((unsigned long)vaddr,
                        (unsigned long)(vaddr + size));
                break;
        default:
                BUG();
        }
}

void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
                enum dma_data_direction dir)
{
        void *vaddr = phys_to_virt(paddr);

        switch (dir) {
        case DMA_BIDIRECTIONAL:
        case DMA_FROM_DEVICE:
                invalidate_dcache_range((unsigned long)vaddr,
                        (unsigned long)(vaddr + size));
                break;
        case DMA_TO_DEVICE:
                break;
        default:
                BUG();
        }
}

void arch_dma_prep_coherent(struct page *page, size_t size)
{
        unsigned long start = (unsigned long)page_address(page);

        flush_dcache_range(start, start + size);
}

void *arch_dma_set_uncached(void *ptr, size_t size)
{
        unsigned long addr = (unsigned long)ptr;

        addr |= CONFIG_NIOS2_IO_REGION_BASE;

        return (void *)ptr;
}