/*

 * QEMU Sparc32 DMA controller emulation

 *

 * Copyright (c) 2006 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "hw.h"

#include "sparc32_dma.h"

#include "sun4m.h"

/* debug DMA */

//#define DEBUG_DMA

/*

 * This is the DMA controller part of chip STP2000 (Master I/O), also

 * produced as NCR89C100. See

 * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C100.txt

 * and

 * http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/DMA2.txt

 */

#ifdef DEBUG_DMA

#define DPRINTF(fmt, args...) \

do { printf("DMA: " fmt , ##args); } while (0)

#else

#define DPRINTF(fmt, args...)

#endif

#define DMA_REGS 4

#define DMA_SIZE (4 * sizeof(uint32_t))

/* We need the mask, because one instance of the device is not page

   aligned (ledma, start address 0x0010) */

#define DMA_MASK (DMA_SIZE - 1)

#define DMA_VER 0xa0000000

#define DMA_INTR 1

#define DMA_INTREN 0x10

#define DMA_WRITE_MEM 0x100

#define DMA_LOADED 0x04000000

#define DMA_DRAIN_FIFO 0x40

#define DMA_RESET 0x80

typedef struct DMAState DMAState;

struct DMAState {

    uint32_t dmaregs[DMA_REGS];

    qemu_irq irq;

    void *iommu;

    qemu_irq dev_reset;

};

/* Note: on sparc, the lance 16 bit bus is swapped */

void ledma_memory_read(void *opaque, target_phys_addr_t addr,

                       uint8_t *buf, int len, int do_bswap)

{

    DMAState *s = opaque;

    int i;

    DPRINTF("DMA write, direction: %c, addr 0x%8.8x\n",

            s->dmaregs[0] & DMA_WRITE_MEM ? 'w': 'r', s->dmaregs[1]);

    addr |= s->dmaregs[3];

    if (do_bswap) {

        sparc_iommu_memory_read(s->iommu, addr, buf, len);

    } else {

        addr &= ~1;

        len &= ~1;

        sparc_iommu_memory_read(s->iommu, addr, buf, len);

        for(i = 0; i < len; i += 2) {

            bswap16s((uint16_t *)(buf + i));

        }

    }

}

void ledma_memory_write(void *opaque, target_phys_addr_t addr,

                        uint8_t *buf, int len, int do_bswap)

{

    DMAState *s = opaque;

    int l, i;

    uint16_t tmp_buf[32];

    DPRINTF("DMA read, direction: %c, addr 0x%8.8x\n",

            s->dmaregs[0] & DMA_WRITE_MEM ? 'w': 'r', s->dmaregs[1]);

    addr |= s->dmaregs[3];

    if (do_bswap) {

        sparc_iommu_memory_write(s->iommu, addr, buf, len);

    } else {

        addr &= ~1;

        len &= ~1;

        while (len > 0) {

            l = len;

            if (l > sizeof(tmp_buf))

                l = sizeof(tmp_buf);

            for(i = 0; i < l; i += 2) {

                tmp_buf[i >> 1] = bswap16(*(uint16_t *)(buf + i));

            }

            sparc_iommu_memory_write(s->iommu, addr, (uint8_t *)tmp_buf, l);

            len -= l;

            buf += l;

            addr += l;

        }

    }

}

static void dma_set_irq(void *opaque, int irq, int level)

{

    DMAState *s = opaque;

    if (level) {

        DPRINTF("Raise IRQ\n");

        s->dmaregs[0] |= DMA_INTR;

        qemu_irq_raise(s->irq);

    } else {

        s->dmaregs[0] &= ~DMA_INTR;

        DPRINTF("Lower IRQ\n");

        qemu_irq_lower(s->irq);

    }

}

void espdma_memory_read(void *opaque, uint8_t *buf, int len)

{

    DMAState *s = opaque;

    DPRINTF("DMA read, direction: %c, addr 0x%8.8x\n",

            s->dmaregs[0] & DMA_WRITE_MEM ? 'w': 'r', s->dmaregs[1]);

    sparc_iommu_memory_read(s->iommu, s->dmaregs[1], buf, len);

    s->dmaregs[0] |= DMA_INTR;

    s->dmaregs[1] += len;

}

void espdma_memory_write(void *opaque, uint8_t *buf, int len)

{

    DMAState *s = opaque;

    DPRINTF("DMA write, direction: %c, addr 0x%8.8x\n",

            s->dmaregs[0] & DMA_WRITE_MEM ? 'w': 'r', s->dmaregs[1]);

    sparc_iommu_memory_write(s->iommu, s->dmaregs[1], buf, len);

    s->dmaregs[0] |= DMA_INTR;

    s->dmaregs[1] += len;

}

static uint32_t dma_mem_readl(void *opaque, target_phys_addr_t addr)

{

    DMAState *s = opaque;

    uint32_t saddr;

    saddr = (addr & DMA_MASK) >> 2;

    DPRINTF("read dmareg " TARGET_FMT_plx ": 0x%8.8x\n", addr,

            s->dmaregs[saddr]);

    return s->dmaregs[saddr];

}

static void dma_mem_writel(void *opaque, target_phys_addr_t addr, uint32_t val)

{

    DMAState *s = opaque;

    uint32_t saddr;

    saddr = (addr & DMA_MASK) >> 2;

    DPRINTF("write dmareg " TARGET_FMT_plx ": 0x%8.8x -> 0x%8.8x\n", addr,

            s->dmaregs[saddr], val);

    switch (saddr) {

    case 0:

        if (!(val & DMA_INTREN)) {

            DPRINTF("Lower IRQ\n");

            qemu_irq_lower(s->irq);

        }

        if (val & DMA_RESET) {

            qemu_irq_raise(s->dev_reset);

            qemu_irq_lower(s->dev_reset);

        } else if (val & DMA_DRAIN_FIFO) {

            val &= ~DMA_DRAIN_FIFO;

        } else if (val == 0)

            val = DMA_DRAIN_FIFO;

        val &= 0x0fffffff;

        val |= DMA_VER;

        break;

    case 1:

        s->dmaregs[0] |= DMA_LOADED;

        break;

    default:

        break;

    }

    s->dmaregs[saddr] = val;

}

static CPUReadMemoryFunc *dma_mem_read[3] = {

    NULL,

    NULL,

    dma_mem_readl,

};

static CPUWriteMemoryFunc *dma_mem_write[3] = {

    NULL,

    NULL,

    dma_mem_writel,

};

static void dma_reset(void *opaque)

{

    DMAState *s = opaque;

    memset(s->dmaregs, 0, DMA_SIZE);

    s->dmaregs[0] = DMA_VER;

}

static void dma_save(QEMUFile *f, void *opaque)

{

    DMAState *s = opaque;

    unsigned int i;

    for (i = 0; i < DMA_REGS; i++)

        qemu_put_be32s(f, &s->dmaregs[i]);

}

static int dma_load(QEMUFile *f, void *opaque, int version_id)

{

    DMAState *s = opaque;

    unsigned int i;

    if (version_id != 2)

        return -EINVAL;

    for (i = 0; i < DMA_REGS; i++)

        qemu_get_be32s(f, &s->dmaregs[i]);

    return 0;

}

void *sparc32_dma_init(target_phys_addr_t daddr, qemu_irq parent_irq,

                       void *iommu, qemu_irq **dev_irq, qemu_irq **reset)

{

    DMAState *s;

    int dma_io_memory;

    s = qemu_mallocz(sizeof(DMAState));

    if (!s)

        return NULL;

    s->irq = parent_irq;

    s->iommu = iommu;

    dma_io_memory = cpu_register_io_memory(0, dma_mem_read, dma_mem_write, s);

    cpu_register_physical_memory(daddr, DMA_SIZE, dma_io_memory);

    register_savevm("sparc32_dma", daddr, 2, dma_save, dma_load, s);

    qemu_register_reset(dma_reset, s);

    *dev_irq = qemu_allocate_irqs(dma_set_irq, s, 1);

    *reset = &s->dev_reset;

    return s;

}