/*

 * QEMU NVRAM emulation for DS1225Y chip

 *

 * Copyright (c) 2007-2008 Hervé Poussineau

 *

 * 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 "mips.h"

#include "nvram.h"

//#define DEBUG_NVRAM

typedef struct ds1225y_t

{

    uint32_t chip_size;

    QEMUFile *file;

    uint8_t *contents;

    uint8_t protection;

} ds1225y_t;

static uint32_t nvram_readb (void *opaque, target_phys_addr_t addr)

{

    ds1225y_t *s = opaque;

    uint32_t val;

    val = s->contents[addr];

#ifdef DEBUG_NVRAM

    printf("nvram: read 0x%x at " TARGET_FMT_lx "\n", val, addr);

#endif

    return val;

}

static uint32_t nvram_readw (void *opaque, target_phys_addr_t addr)

{

    uint32_t v;

    v = nvram_readb(opaque, addr);

    v |= nvram_readb(opaque, addr + 1) << 8;

    return v;

}

static uint32_t nvram_readl (void *opaque, target_phys_addr_t addr)

{

    uint32_t v;

    v = nvram_readb(opaque, addr);

    v |= nvram_readb(opaque, addr + 1) << 8;

    v |= nvram_readb(opaque, addr + 2) << 16;

    v |= nvram_readb(opaque, addr + 3) << 24;

    return v;

}

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

{

    ds1225y_t *s = opaque;

#ifdef DEBUG_NVRAM

    printf("nvram: write 0x%x at " TARGET_FMT_lx "\n", val, addr);

#endif

    s->contents[addr] = val & 0xff;

    if (s->file) {

        qemu_fseek(s->file, addr, SEEK_SET);

        qemu_put_byte(s->file, (int)val);

        qemu_fflush(s->file);

    }

}

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

{

    nvram_writeb(opaque, addr, val & 0xff);

    nvram_writeb(opaque, addr + 1, (val >> 8) & 0xff);

}

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

{

    nvram_writeb(opaque, addr, val & 0xff);

    nvram_writeb(opaque, addr + 1, (val >> 8) & 0xff);

    nvram_writeb(opaque, addr + 2, (val >> 16) & 0xff);

    nvram_writeb(opaque, addr + 3, (val >> 24) & 0xff);

}

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

{

    ds1225y_t *s = opaque;

    if (s->protection != 7) {

#ifdef DEBUG_NVRAM

    printf("nvram: prevent write of 0x%x at " TARGET_FMT_lx "\n", val, addr);

#endif

        return;

    }

    nvram_writeb(opaque, addr, val);

}

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

{

    nvram_writeb_protected(opaque, addr, val & 0xff);

    nvram_writeb_protected(opaque, addr + 1, (val >> 8) & 0xff);

}

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

{

    nvram_writeb_protected(opaque, addr, val & 0xff);

    nvram_writeb_protected(opaque, addr + 1, (val >> 8) & 0xff);

    nvram_writeb_protected(opaque, addr + 2, (val >> 16) & 0xff);

    nvram_writeb_protected(opaque, addr + 3, (val >> 24) & 0xff);

}

static CPUReadMemoryFunc *nvram_read[] = {

    &nvram_readb,

    &nvram_readw,

    &nvram_readl,

};

static CPUWriteMemoryFunc *nvram_write[] = {

    &nvram_writeb,

    &nvram_writew,

    &nvram_writel,

};

static CPUWriteMemoryFunc *nvram_write_protected[] = {

    &nvram_writeb_protected,

    &nvram_writew_protected,

    &nvram_writel_protected,

};

/* Initialisation routine */

void *ds1225y_init(target_phys_addr_t mem_base, const char *filename)

{

    ds1225y_t *s;

    int mem_indexRW, mem_indexRP;

    QEMUFile *file;

    s = qemu_mallocz(sizeof(ds1225y_t));

    if (!s)

        return NULL;

    s->chip_size = 0x2000; /* Fixed for ds1225y chip: 8 KiB */

    s->contents = qemu_mallocz(s->chip_size);

    if (!s->contents) {

        return NULL;

    }

    s->protection = 7;

    /* Read current file */

    file = qemu_fopen(filename, "rb");

    if (file) {

        /* Read nvram contents */

        qemu_get_buffer(file, s->contents, s->chip_size);

        qemu_fclose(file);

    }

    s->file = qemu_fopen(filename, "wb");

    if (s->file) {

        /* Write back contents, as 'wb' mode cleaned the file */

        qemu_put_buffer(s->file, s->contents, s->chip_size);

        qemu_fflush(s->file);

    }

    /* Read/write memory */

    mem_indexRW = cpu_register_io_memory(0, nvram_read, nvram_write, s);

    cpu_register_physical_memory(mem_base, s->chip_size, mem_indexRW);

    /* Read/write protected memory */

    mem_indexRP = cpu_register_io_memory(0, nvram_read, nvram_write_protected, s);

    cpu_register_physical_memory(mem_base + s->chip_size, s->chip_size, mem_indexRP);

    return s;

}