/*
 * SSD0323 OLED controller with OSRAM Pictiva 128x64 display.
 *
 * Copyright (c) 2006-2007 CodeSourcery.
 * Written by Paul Brook
 *
 * This code is licenced under the GPL.
 */

/* The controller can support a variety of different displays, but we only
   implement one.  Most of the commends relating to brightness and geometry
   setup are ignored. */
#include "hw.h"
#include "devices.h"
#include "console.h"

//#define DEBUG_SSD0323 1

#ifdef DEBUG_SSD0323
#define DPRINTF(fmt, args...) \
do { printf("ssd0323: " fmt , ##args); } while (0)
#define BADF(fmt, args...) \
do { fprintf(stderr, "ssd0323: error: " fmt , ##args); exit(1);} while (0)
#else
#define DPRINTF(fmt, args...) do {} while(0)
#define BADF(fmt, args...) \
do { fprintf(stderr, "ssd0323: error: " fmt , ##args);} while (0)
#endif

/* Scaling factor for pixels.  */
#define MAGNIFY 4

#define REMAP_SWAP_COLUMN 0x01
#define REMAP_SWAP_NYBBLE 0x02
#define REMAP_VERTICAL    0x04
#define REMAP_SWAP_COM    0x10
#define REMAP_SPLIT_COM   0x40

enum ssd0323_mode
{
    SSD0323_CMD,
    SSD0323_DATA
};

typedef struct {
    DisplayState *ds;

    int cmd_len;
    int cmd;
    int cmd_data[8];
    int row;
    int row_start;
    int row_end;
    int col;
    int col_start;
    int col_end;
    int redraw;
    int remap;
    enum ssd0323_mode mode;
    uint8_t framebuffer[128 * 80 / 2];
} ssd0323_state;

int ssd0323_xfer_ssi(void *opaque, int data)
{
    ssd0323_state *s = (ssd0323_state *)opaque;
    switch (s->mode) {
    case SSD0323_DATA:
        DPRINTF("data 0x%02x\n", data);
        s->framebuffer[s->col + s->row * 64] = data;
        if (s->remap & REMAP_VERTICAL) {
            s->row++;
            if (s->row > s->row_end) {
                s->row = s->row_start;
                s->col++;
            }
            if (s->col > s->col_end) {
                s->col = s->col_start;
            }
        } else {
            s->col++;
            if (s->col > s->col_end) {
                s->row++;
                s->col = s->col_start;
            }
            if (s->row > s->row_end) {
                s->row = s->row_start;
            }
        }
        s->redraw = 1;
        break;
    case SSD0323_CMD:
        DPRINTF("cmd 0x%02x\n", data);
        if (s->cmd_len == 0) {
            s->cmd = data;
        } else {
            s->cmd_data[s->cmd_len - 1] = data;
        }
        s->cmd_len++;
        switch (s->cmd) {
#define DATA(x) if (s->cmd_len <= (x)) return 0
        case 0x15: /* Set column.  */
            DATA(2);
            s->col = s->col_start = s->cmd_data[0] % 64;
            s->col_end = s->cmd_data[1] % 64;
            break;
        case 0x75: /* Set row.  */
            DATA(2);
            s->row = s->row_start = s->cmd_data[0] % 80;
            s->row_end = s->cmd_data[1] % 80;
            break;
        case 0x81: /* Set contrast */
            DATA(1);
            break;
        case 0x84: case 0x85: case 0x86: /* Max current.  */
            DATA(0);
            break;
        case 0xa0: /* Set remapping.  */
            /* FIXME: Implement this.  */
            DATA(1);
            s->remap = s->cmd_data[0];
            break;
        case 0xa1: /* Set display start line.  */
        case 0xa2: /* Set display offset.  */
            /* FIXME: Implement these.  */
            DATA(1);
            break;
        case 0xa4: /* Normal mode.  */
        case 0xa5: /* All on.  */
        case 0xa6: /* All off.  */
        case 0xa7: /* Inverse.  */
            /* FIXME: Implement these.  */
            DATA(0);
            break;
        case 0xa8: /* Set multiplex ratio.  */
        case 0xad: /* Set DC-DC converter.  */
            DATA(1);
            /* Ignored.  Don't care.  */
            break;
        case 0xae: /* Display off.  */
        case 0xaf: /* Display on.  */
            DATA(0);
            /* TODO: Implement power control.  */
            break;
        case 0xb1: /* Set phase length.  */
        case 0xb2: /* Set row period.  */
        case 0xb3: /* Set clock rate.  */
        case 0xbc: /* Set precharge.  */
        case 0xbe: /* Set VCOMH.  */
        case 0xbf: /* Set segment low.  */
            DATA(1);
            /* Ignored.  Don't care.  */
            break;
        case 0xb8: /* Set grey scale table.  */
            /* FIXME: Implement this.  */
            DATA(8);
            break;
        case 0xe3: /* NOP.  */
            DATA(0);
            break;
        case 0xff: /* Nasty hack because we don't handle chip selects
                      properly.  */
            break;
        default:
            BADF("Unknown command: 0x%x\n", data);
        }
        s->cmd_len = 0;
        return 0;
    }
    return 0;
}

static void ssd0323_update_display(void *opaque)
{
    ssd0323_state *s = (ssd0323_state *)opaque;
    uint8_t *dest;
    uint8_t *src;
    int x;
    int y;
    int i;
    int line;
    char *colors[16];
    char colortab[MAGNIFY * 64];
    char *p;
    int dest_width;

    if (s->redraw) {
        switch (s->ds->depth) {
        case 0:
            return;
        case 15:
            dest_width = 2;
            break;
        case 16:
            dest_width = 2;
            break;
        case 24:
            dest_width = 3;
            break;
        case 32:
            dest_width = 4;
            break;
        default:
            BADF("Bad color depth\n");
            return;
        }
        p = colortab;
        for (i = 0; i < 16; i++) {
            int n;
            colors[i] = p;
            switch (s->ds->depth) {
            case 15:
                n = i * 2 + (i >> 3);
                p[0] = n | (n << 5);
                p[1] = (n << 2) | (n >> 3);
                break;
            case 16:
                n = i * 2 + (i >> 3);
                p[0] = n | (n << 6) | ((n << 1) & 0x20);
                p[1] = (n << 3) | (n >> 2);
                break;
            case 24:
            case 32:
                n = (i << 4) | i;
                p[0] = p[1] = p[2] = n;
                break;
            default:
                BADF("Bad color depth\n");
                return;
            }
            p += dest_width;
        }
        /* TODO: Implement row/column remapping.  */
        dest = s->ds->data;
        for (y = 0; y < 64; y++) {
            line = y;
            src = s->framebuffer + 64 * line;
            for (x = 0; x < 64; x++) {
                int val;
                val = *src >> 4;
                for (i = 0; i < MAGNIFY; i++) {
                    memcpy(dest, colors[val], dest_width);
                    dest += dest_width;
                }
                val = *src & 0xf;
                for (i = 0; i < MAGNIFY; i++) {
                    memcpy(dest, colors[val], dest_width);
                    dest += dest_width;
                }
                src++;
            }
            for (i = 1; i < MAGNIFY; i++) {
                memcpy(dest, dest - dest_width * MAGNIFY * 128,
                       dest_width * 128 * MAGNIFY);
                dest += dest_width * 128 * MAGNIFY;
            }
        }
    }
    dpy_update(s->ds, 0, 0, 128 * MAGNIFY, 64 * MAGNIFY);
}

static void ssd0323_invalidate_display(void * opaque)
{
    ssd0323_state *s = (ssd0323_state *)opaque;
    s->redraw = 1;
}

/* Command/data input.  */
static void ssd0323_cd(void *opaque, int n, int level)
{
    ssd0323_state *s = (ssd0323_state *)opaque;
    DPRINTF("%s mode\n", level ? "Data" : "Command");
    s->mode = level ? SSD0323_DATA : SSD0323_CMD;
}

void *ssd0323_init(DisplayState *ds, qemu_irq *cmd_p)
{
    ssd0323_state *s;
    qemu_irq *cmd;

    s = (ssd0323_state *)qemu_mallocz(sizeof(ssd0323_state));
    s->ds = ds;
    graphic_console_init(ds, ssd0323_update_display, ssd0323_invalidate_display,
                         NULL, s);
    dpy_resize(s->ds, 128 * MAGNIFY, 64 * MAGNIFY);
    s->col_end = 63;
    s->row_end = 79;

    cmd = qemu_allocate_irqs(ssd0323_cd, s, 1);
    *cmd_p = *cmd;

    return s;
}