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/*

 * QEMU Sparc32 DMA controller emulation

 *

 * Copyright (c) 2006 Fabrice Bellard

 *

 * Modifications:

 *  2010-Feb-14 Artyom Tarasenko : reworked irq generation

 *

 * 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"

#include "sysbus.h"

#include "trace.h"

/*

 * 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

 */

#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)

/* OBP says 0x20 bytes for ledma, the extras are aliased to espdma */

#define DMA_ETH_SIZE (8 * sizeof(uint32_t))

#define DMA_MAX_REG_OFFSET (2 * DMA_SIZE - 1)

#define DMA_VER 0xa0000000

#define DMA_INTR 1

#define DMA_INTREN 0x10

#define DMA_WRITE_MEM 0x100

#define DMA_EN 0x200

#define DMA_LOADED 0x04000000

#define DMA_DRAIN_FIFO 0x40

#define DMA_RESET 0x80

/* XXX SCSI and ethernet should have different read-only bit masks */

#define DMA_CSR_RO_MASK 0xfe000007

typedef struct DMAState DMAState;

struct DMAState {

    SysBusDevice busdev;

    uint32_t dmaregs[DMA_REGS];

    qemu_irq irq;

    void *iommu;

    qemu_irq gpio[2];

    uint32_t is_ledma;

};

enum {

    GPIO_RESET = 0,

    GPIO_DMA,

};

/* 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;

    addr |= s->dmaregs[3];

    trace_ledma_memory_read(addr);

    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];

    addr |= s->dmaregs[3];

    trace_ledma_memory_write(addr);

    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) {

        s->dmaregs[0] |= DMA_INTR;

        if (s->dmaregs[0] & DMA_INTREN) {

            trace_sparc32_dma_set_irq_raise();

            qemu_irq_raise(s->irq);

        }

    } else {

        if (s->dmaregs[0] & DMA_INTR) {

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

            if (s->dmaregs[0] & DMA_INTREN) {

                trace_sparc32_dma_set_irq_lower();

                qemu_irq_lower(s->irq);

            }

        }

    }

}

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

{

    DMAState *s = opaque;

    trace_espdma_memory_read(s->dmaregs[1]);

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

    s->dmaregs[1] += len;

}

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

{

    DMAState *s = opaque;

    trace_espdma_memory_write(s->dmaregs[1]);

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

    s->dmaregs[1] += len;

}

static uint32_t dma_mem_readl(void *opaque, target_phys_addr_t addr)

{

    DMAState *s = opaque;

    uint32_t saddr;

    if (s->is_ledma && (addr > DMA_MAX_REG_OFFSET)) {

        /* aliased to espdma, but we can't get there from here */

        /* buggy driver if using undocumented behavior, just return 0 */

        trace_sparc32_dma_mem_readl(addr, 0);

        return 0;

    }

    saddr = (addr & DMA_MASK) >> 2;

    trace_sparc32_dma_mem_readl(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;

    if (s->is_ledma && (addr > DMA_MAX_REG_OFFSET)) {

        /* aliased to espdma, but we can't get there from here */

        trace_sparc32_dma_mem_writel(addr, 0, val);

        return;

    }

    saddr = (addr & DMA_MASK) >> 2;

    trace_sparc32_dma_mem_writel(addr, s->dmaregs[saddr], val);

    switch (saddr) {

    case 0:

        if (val & DMA_INTREN) {

            if (s->dmaregs[0] & DMA_INTR) {

                trace_sparc32_dma_set_irq_raise();

                qemu_irq_raise(s->irq);

            }

        } else {

            if (s->dmaregs[0] & (DMA_INTR | DMA_INTREN)) {

                trace_sparc32_dma_set_irq_lower();

                qemu_irq_lower(s->irq);

            }

        }

        if (val & DMA_RESET) {

            qemu_irq_raise(s->gpio[GPIO_RESET]);

            qemu_irq_lower(s->gpio[GPIO_RESET]);

        } else if (val & DMA_DRAIN_FIFO) {

            val &= ~DMA_DRAIN_FIFO;

        } else if (val == 0)

            val = DMA_DRAIN_FIFO;

        if (val & DMA_EN && !(s->dmaregs[0] & DMA_EN)) {

            trace_sparc32_dma_enable_raise();

            qemu_irq_raise(s->gpio[GPIO_DMA]);

        } else if (!(val & DMA_EN) && !!(s->dmaregs[0] & DMA_EN)) {

            trace_sparc32_dma_enable_lower();

            qemu_irq_lower(s->gpio[GPIO_DMA]);

        }

        val &= ~DMA_CSR_RO_MASK;

        val |= DMA_VER;

        s->dmaregs[0] = (s->dmaregs[0] & DMA_CSR_RO_MASK) | val;

        break;

    case 1:

        s->dmaregs[0] |= DMA_LOADED;

        /* fall through */

    default:

        s->dmaregs[saddr] = val;

        break;

    }

}

static CPUReadMemoryFunc * const dma_mem_read[3] = {

    NULL,

    NULL,

    dma_mem_readl,

};

static CPUWriteMemoryFunc * const dma_mem_write[3] = {

    NULL,

    NULL,

    dma_mem_writel,

};

static void dma_reset(DeviceState *d)

{

    DMAState *s = container_of(d, DMAState, busdev.qdev);

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

    s->dmaregs[0] = DMA_VER;

}

static const VMStateDescription vmstate_dma = {

    .name ="sparc32_dma",

    .version_id = 2,

    .minimum_version_id = 2,

    .minimum_version_id_old = 2,

    .fields      = (VMStateField []) {

        VMSTATE_UINT32_ARRAY(dmaregs, DMAState, DMA_REGS),

        VMSTATE_END_OF_LIST()

    }

};

static int sparc32_dma_init1(SysBusDevice *dev)

{

    DMAState *s = FROM_SYSBUS(DMAState, dev);

    int dma_io_memory;

    int reg_size;

    sysbus_init_irq(dev, &s->irq);

    dma_io_memory = cpu_register_io_memory(dma_mem_read, dma_mem_write, s,

                                           DEVICE_NATIVE_ENDIAN);

    reg_size = s->is_ledma ? DMA_ETH_SIZE : DMA_SIZE;

    sysbus_init_mmio(dev, reg_size, dma_io_memory);

    qdev_init_gpio_in(&dev->qdev, dma_set_irq, 1);

    qdev_init_gpio_out(&dev->qdev, s->gpio, 2);

    return 0;

}

static SysBusDeviceInfo sparc32_dma_info = {

    .init = sparc32_dma_init1,

    .qdev.name  = "sparc32_dma",

    .qdev.size  = sizeof(DMAState),

    .qdev.vmsd  = &vmstate_dma,

    .qdev.reset = dma_reset,

    .qdev.props = (Property[]) {

        DEFINE_PROP_PTR("iommu_opaque", DMAState, iommu),

        DEFINE_PROP_UINT32("is_ledma", DMAState, is_ledma, 0),

        DEFINE_PROP_END_OF_LIST(),

    }

};

static void sparc32_dma_register_devices(void)

{

    sysbus_register_withprop(&sparc32_dma_info);

}

device_init(sparc32_dma_register_devices)