/*
 * TC58128 NAND EEPROM emulation
 *
 * Copyright (c) 2005 Samuel Tardieu
 *
 * 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 (including the next
 * paragraph) 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.
 *
 * SPDX-License-Identifier: MIT
 */
#include "qemu/osdep.h"
#include "qemu/units.h"
#include "hw/sh4/sh.h"
#include "hw/loader.h"
#include "sysemu/qtest.h"
#include "qemu/error-report.h"

#define CE1  0x0100
#define CE2  0x0200
#define RE   0x0400
#define WE   0x0800
#define ALE  0x1000
#define CLE  0x2000
#define RDY1 0x4000
#define RDY2 0x8000
#define RDY(n) ((n) == 0 ? RDY1 : RDY2)

typedef enum { WAIT, READ1, READ2, READ3 } state_t;

typedef struct {
    uint8_t *flash_contents;
    state_t state;
    uint32_t address;
    uint8_t address_cycle;
} tc58128_dev;

static tc58128_dev tc58128_devs[2];

#define FLASH_SIZE (16 * MiB)

static void init_dev(tc58128_dev * dev, const char *filename)
{
    int ret, blocks;

    dev->state = WAIT;
    dev->flash_contents = g_malloc(FLASH_SIZE);
    memset(dev->flash_contents, 0xff, FLASH_SIZE);
    if (filename) {
        /* Load flash image skipping the first block */
        ret = load_image_size(filename, dev->flash_contents + 528 * 32,
                              FLASH_SIZE - 528 * 32);
        if (ret < 0) {
            if (!qtest_enabled()) {
                error_report("Could not load flash image %s", filename);
                exit(1);
            }
        } else {
            /* Build first block with number of blocks */
            blocks = DIV_ROUND_UP(ret, 528 * 32);
            dev->flash_contents[0] = blocks & 0xff;
            dev->flash_contents[1] = (blocks >> 8) & 0xff;
            dev->flash_contents[2] = (blocks >> 16) & 0xff;
            dev->flash_contents[3] = (blocks >> 24) & 0xff;
            fprintf(stderr, "loaded %d bytes for %s into flash\n", ret,
                    filename);
        }
    }
}

static void handle_command(tc58128_dev * dev, uint8_t command)
{
    switch (command) {
    case 0xff:
        fprintf(stderr, "reset flash device\n");
        dev->state = WAIT;
        break;
    case 0x00:
        fprintf(stderr, "read mode 1\n");
        dev->state = READ1;
        dev->address_cycle = 0;
        break;
    case 0x01:
        fprintf(stderr, "read mode 2\n");
        dev->state = READ2;
        dev->address_cycle = 0;
        break;
    case 0x50:
        fprintf(stderr, "read mode 3\n");
        dev->state = READ3;
        dev->address_cycle = 0;
        break;
    default:
        fprintf(stderr, "unknown flash command 0x%02x\n", command);
        abort();
    }
}

static void handle_address(tc58128_dev * dev, uint8_t data)
{
    switch (dev->state) {
    case READ1:
    case READ2:
    case READ3:
        switch (dev->address_cycle) {
        case 0:
            dev->address = data;
            if (dev->state == READ2)
                dev->address |= 0x100;
            else if (dev->state == READ3)
                dev->address |= 0x200;
            break;
        case 1:
            dev->address += data * 528 * 0x100;
            break;
        case 2:
            dev->address += data * 528;
            fprintf(stderr, "address pointer in flash: 0x%08x\n",
                    dev->address);
            break;
        default:
            /* Invalid data */
            abort();
        }
        dev->address_cycle++;
        break;
    default:
        abort();
    }
}

static uint8_t handle_read(tc58128_dev * dev)
{
#if 0
    if (dev->address % 0x100000 == 0)
        fprintf(stderr, "reading flash at address 0x%08x\n", dev->address);
#endif
    return dev->flash_contents[dev->address++];
}

/* We never mark the device as busy, so interrupts cannot be triggered
   XXXXX */

static int tc58128_cb(uint16_t porta, uint16_t portb,
                      uint16_t * periph_pdtra, uint16_t * periph_portadir,
                      uint16_t * periph_pdtrb, uint16_t * periph_portbdir)
{
    int dev;

    if ((porta & CE1) == 0)
        dev = 0;
    else if ((porta & CE2) == 0)
        dev = 1;
    else
        return 0;        /* No device selected */

    if ((porta & RE) && (porta & WE)) {
        /* Nothing to do, assert ready and return to input state */
        *periph_portadir &= 0xff00;
        *periph_portadir |= RDY(dev);
        *periph_pdtra |= RDY(dev);
        return 1;
    }

    if (porta & CLE) {
        /* Command */
        assert((porta & WE) == 0);
        handle_command(&tc58128_devs[dev], porta & 0x00ff);
    } else if (porta & ALE) {
        assert((porta & WE) == 0);
        handle_address(&tc58128_devs[dev], porta & 0x00ff);
    } else if ((porta & RE) == 0) {
        *periph_portadir |= 0x00ff;
        *periph_pdtra &= 0xff00;
        *periph_pdtra |= handle_read(&tc58128_devs[dev]);
    } else {
        abort();
    }
    return 1;
}

static sh7750_io_device tc58128 = {
    RE | WE,            /* Port A triggers */
    0,                  /* Port B triggers */
    tc58128_cb          /* Callback */
};

int tc58128_init(struct SH7750State *s, const char *zone1, const char *zone2)
{
    init_dev(&tc58128_devs[0], zone1);
    init_dev(&tc58128_devs[1], zone2);
    return sh7750_register_io_device(s, &tc58128);
}