/* $Id: g364fb.c,v 1.3 1998/08/28 22:43:00 tsbogend Exp $
 *
 * linux/drivers/video/g364fb.c -- Mips Magnum frame buffer device
 *
 * (C) 1998 Thomas Bogendoerfer
 *
 *  This driver is based on tgafb.c
 *
 *      Copyright (C) 1997 Geert Uytterhoeven 
 *      Copyright (C) 1995  Jay Estabrook
 *
 *  This file is subject to the terms and conditions of the GNU General Public
 *  License. See the file COPYING in the main directory of this archive for
 *  more details.
 */

#include <linux/module.h>
#include <linux/console.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/jazz.h>

/* 
 * Various defines for the G364
 */
#define G364_MEM_BASE   0xe4400000
#define G364_PORT_BASE  0xe4000000
#define ID_REG          0xe4000000      /* Read only */
#define BOOT_REG        0xe4080000
#define TIMING_REG      0xe4080108      /* to 0x080170 - DON'T TOUCH! */
#define DISPLAY_REG     0xe4080118
#define VDISPLAY_REG    0xe4080150
#define MASK_REG        0xe4080200
#define CTLA_REG        0xe4080300
#define CURS_TOGGLE     0x800000
#define BIT_PER_PIX     0x700000        /* bits 22 to 20 of Control A */
#define DELAY_SAMPLE    0x080000
#define PORT_INTER      0x040000
#define PIX_PIPE_DEL    0x030000        /* bits 17 and 16 of Control A */
#define PIX_PIPE_DEL2   0x008000        /* same as above - don't ask me why */
#define TR_CYCLE_TOG    0x004000
#define VRAM_ADR_INC    0x003000        /* bits 13 and 12 of Control A */
#define BLANK_OFF       0x000800
#define FORCE_BLANK     0x000400
#define BLK_FUN_SWTCH   0x000200
#define BLANK_IO        0x000100
#define BLANK_LEVEL     0x000080
#define A_VID_FORM      0x000040
#define D_SYNC_FORM     0x000020
#define FRAME_FLY_PAT   0x000010
#define OP_MODE         0x000008
#define INTL_STAND      0x000004
#define SCRN_FORM       0x000002
#define ENABLE_VTG      0x000001
#define TOP_REG         0xe4080400
#define CURS_PAL_REG    0xe4080508      /* to 0x080518 */
#define CHKSUM_REG      0xe4080600      /* to 0x080610 - unused */
#define CURS_POS_REG    0xe4080638
#define CLR_PAL_REG     0xe4080800      /* to 0x080ff8 */
#define CURS_PAT_REG    0xe4081000      /* to 0x081ff8 */
#define MON_ID_REG      0xe4100000      /* unused */
#define RESET_REG       0xe4180000      /* Write only */

static struct fb_info fb_info;

static struct fb_fix_screeninfo fb_fix __initdata = {
        .id             = "G364 8plane",
        .smem_start     = 0x40000000,   /* physical address */
        .type           = FB_TYPE_PACKED_PIXELS,
        .visual         = FB_VISUAL_PSEUDOCOLOR,
        .ypanstep       = 1,
        .accel          = FB_ACCEL_NONE,
};

static struct fb_var_screeninfo fb_var __initdata = {
        .bits_per_pixel = 8,
        .red            = { 0, 8, 0 },
        .green          = { 0, 8, 0 },
        .blue           = { 0, 8, 0 },
        .activate       = FB_ACTIVATE_NOW,
        .height         = -1,
        .width          = -1,
        .pixclock       = 39722,
        .left_margin    = 40,
        .right_margin   = 24,
        .upper_margin   = 32,
        .lower_margin   = 11,
        .hsync_len      = 96,
        .vsync_len      = 2,
        .vmode          = FB_VMODE_NONINTERLACED,
};

/*
 *  Interface used by the world
 */
int g364fb_init(void);

static int g364fb_pan_display(struct fb_var_screeninfo *var,
                              struct fb_info *info);
static int g364fb_setcolreg(u_int regno, u_int red, u_int green,
                            u_int blue, u_int transp,
                            struct fb_info *info);
static int g364fb_blank(int blank, struct fb_info *info);

static const struct fb_ops g364fb_ops = {
        .owner          = THIS_MODULE,
        .fb_setcolreg   = g364fb_setcolreg,
        .fb_pan_display = g364fb_pan_display,
        .fb_blank       = g364fb_blank,
        .fb_fillrect    = cfb_fillrect,
        .fb_copyarea    = cfb_copyarea,
        .fb_imageblit   = cfb_imageblit,
};

/*
 *  Pan or Wrap the Display
 *
 *  This call looks only at xoffset, yoffset and the FB_VMODE_YWRAP flag
 */
static int g364fb_pan_display(struct fb_var_screeninfo *var, 
                              struct fb_info *info)
{
        if (var->xoffset ||
            var->yoffset + info->var.yres > info->var.yres_virtual)
                return -EINVAL;

        *(unsigned int *) TOP_REG = var->yoffset * info->var.xres;
        return 0;
}

/*
 *  Blank the display.
 */
static int g364fb_blank(int blank, struct fb_info *info)
{
        if (blank)
                *(unsigned int *) CTLA_REG |= FORCE_BLANK;
        else
                *(unsigned int *) CTLA_REG &= ~FORCE_BLANK;
        return 0;
}

/*
 *  Set a single color register. Return != 0 for invalid regno.
 */
static int g364fb_setcolreg(u_int regno, u_int red, u_int green,
                            u_int blue, u_int transp, struct fb_info *info)
{
        volatile unsigned int *ptr = (volatile unsigned int *) CLR_PAL_REG;

        if (regno > 255)
                return 1;

        red >>= 8;
        green >>= 8;
        blue >>= 8;

        ptr[regno << 1] = (red << 16) | (green << 8) | blue;

        return 0;
}

/*
 *  Initialisation
 */
int __init g364fb_init(void)
{
        volatile unsigned int *curs_pal_ptr =
            (volatile unsigned int *) CURS_PAL_REG;
        int mem, i;

        if (fb_get_options("g364fb", NULL))
                return -ENODEV;

        /* TBD: G364 detection */

        /* get the resolution set by ARC console */
        *(volatile unsigned int *) CTLA_REG &= ~ENABLE_VTG;
        fb_var.xres =
            (*((volatile unsigned int *) DISPLAY_REG) & 0x00ffffff) * 4;
        fb_var.yres =
            (*((volatile unsigned int *) VDISPLAY_REG) & 0x00ffffff) / 2;
        *(volatile unsigned int *) CTLA_REG |= ENABLE_VTG;

        /* setup cursor */
        curs_pal_ptr[0] |= 0x00ffffff;
        curs_pal_ptr[2] |= 0x00ffffff;
        curs_pal_ptr[4] |= 0x00ffffff;

        /*
         * first set the whole cursor to transparent
         */
        for (i = 0; i < 512; i++)
                *(unsigned short *) (CURS_PAT_REG + i * 8) = 0;

        /*
         * switch the last two lines to cursor palette 3
         * we assume here, that FONTSIZE_X is 8
         */
        *(unsigned short *) (CURS_PAT_REG + 14 * 64) = 0xffff;
        *(unsigned short *) (CURS_PAT_REG + 15 * 64) = 0xffff;
        fb_var.xres_virtual = fb_var.xres;
        fb_fix.line_length = fb_var.xres_virtual * fb_var.bits_per_pixel / 8;
        fb_fix.smem_start = 0x40000000; /* physical address */
        /* get size of video memory; this is special for the JAZZ hardware */
        mem = (r4030_read_reg32(JAZZ_R4030_CONFIG) >> 8) & 3;
        fb_fix.smem_len = (1 << (mem * 2)) * 512 * 1024;
        fb_var.yres_virtual = fb_fix.smem_len / fb_var.xres;

        fb_info.fbops = &g364fb_ops;
        fb_info.screen_base = (char *) G364_MEM_BASE;   /* virtual kernel address */
        fb_info.var = fb_var;
        fb_info.fix = fb_fix;
        fb_info.flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;

        fb_alloc_cmap(&fb_info.cmap, 255, 0);

        if (register_framebuffer(&fb_info) < 0)
                return -EINVAL;
        return 0;
}

module_init(g364fb_init);
MODULE_LICENSE("GPL");