fm2fb.c

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/*
 *  linux/drivers/video/fm2fb.c -- BSC FrameMaster II/Rainbow II frame buffer
 *                 device
 *
 *  Copyright (C) 1998 Steffen A. Mork ([email protected])
 *  Copyright (C) 1999 Geert Uytterhoeven
 *
 *  Written for 2.0.x by Steffen A. Mork
 *  Ported to 2.1.x by Geert Uytterhoeven
 *  Ported to new api by James Simmons
 *
 *  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/mm.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/zorro.h>
#include <asm/io.h>

/*
 *  Some technical notes:
 *
 *  The BSC FrameMaster II (or Rainbow II) is a simple very dumb
 *  frame buffer which allows to display 24 bit true color images.
 *  Each pixel is 32 bit width so it's very easy to maintain the
 *  frame buffer. One long word has the following layout:
 *  AARRGGBB which means: AA the alpha channel byte, RR the red
 *  channel, GG the green channel and BB the blue channel.
 *
 *  The FrameMaster II supports the following video modes.
 *  - PAL/NTSC
 *  - interlaced/non interlaced
 *  - composite sync/sync/sync over green
 *
 *  The resolution is to the following both ones:
 *  - 768x576 (PAL)
 *  - 768x480 (NTSC)
 *
 *  This means that pixel access per line is fixed due to the
 *  fixed line width. In case of maximal resolution the frame
 *  buffer needs an amount of memory of 1.769.472 bytes which
 *  is near to 2 MByte (the allocated address space of Zorro2).
 *  The memory is channel interleaved. That means every channel
 *  owns four VRAMs. Unfortunately most FrameMasters II are
 *  not assembled with memory for the alpha channel. In this
 *  case it could be possible to add the frame buffer into the
 *  normal memory pool.
 *
 *  At relative address 0x1ffff8 of the frame buffers base address
 *  there exists a control register with the number of
 *  four control bits. They have the following meaning:
 *  bit value meaning
 *
 *   0    1   0=interlaced/1=non interlaced
 *   1    2   0=video out disabled/1=video out enabled
 *   2    4   0=normal mode as jumpered via JP8/1=complement mode
 *   3    8   0=read  onboard ROM/1 normal operation (required)
 *
 *  As mentioned above there are several jumper. I think there
 *  is not very much information about the FrameMaster II in
 *  the world so I add these information for completeness.
 *
 *  JP1  interlace selection (1-2 non interlaced/2-3 interlaced)
 *  JP2  wait state creation (leave as is!)
 *  JP3  wait state creation (leave as is!)
 *  JP4  modulate composite sync on green output (1-2 composite
 *       sync on green channel/2-3 normal composite sync)
 *  JP5  create test signal, shorting this jumper will create
 *       a white screen
 *  JP6  sync creation (1-2 composite sync/2-3 H-sync output)
 *  JP8  video mode (1-2 PAL/2-3 NTSC)
 *
 *  With the following jumpering table you can connect the
 *  FrameMaster II to a normal TV via SCART connector:
 *  JP1:  2-3
 *  JP4:  2-3
 *  JP6:  2-3
 *  JP8:  1-2 (means PAL for Europe)
 *
 *  NOTE:
 *  There is no other possibility to change the video timings
 *  except the interlaced/non interlaced, sync control and the
 *  video mode PAL (50 Hz)/NTSC (60 Hz). Inside this
 *  FrameMaster II driver are assumed values to avoid anomalies
 *  to a future X server. Except the pixel clock is really
 *  constant at 30 MHz.
 *
 *  9 pin female video connector:
 *
 *  1  analog red 0.7 Vss
 *  2  analog green 0.7 Vss
 *  3  analog blue 0.7 Vss
 *  4  H-sync TTL
 *  5  V-sync TTL
 *  6  ground
 *  7  ground
 *  8  ground
 *  9  ground
 *
 *  Some performance notes:
 *  The FrameMaster II was not designed to display a console
 *  this driver would do! It was designed to display still true
 *  color images. Imagine: When scroll up a text line there
 *  must copied ca. 1.7 MBytes to another place inside this
 *  frame buffer. This means 1.7 MByte read and 1.7 MByte write
 *  over the slow 16 bit wide Zorro2 bus! A scroll of one
 *  line needs 1 second so do not expect to much from this
 *  driver - he is at the limit!
 *
 */

/*
 *  definitions
 */

#define FRAMEMASTER_SIZE    0x200000
#define FRAMEMASTER_REG     0x1ffff8

#define FRAMEMASTER_NOLACE  1
#define FRAMEMASTER_ENABLE  2
#define FRAMEMASTER_COMPL   4
#define FRAMEMASTER_ROM     8

static volatile unsigned char *fm2fb_reg;

static struct fb_fix_screeninfo fb_fix __devinitdata = {
    .smem_len = FRAMEMASTER_REG,
    .type =     FB_TYPE_PACKED_PIXELS,
    .visual =   FB_VISUAL_TRUECOLOR,
    .line_length =  (768 << 2),
    .mmio_len = (8),
    .accel =    FB_ACCEL_NONE,
};

static int fm2fb_mode __devinitdata = -1;

#define FM2FB_MODE_PAL  0
#define FM2FB_MODE_NTSC 1

static struct fb_var_screeninfo fb_var_modes[] __devinitdata = {
    {
    /* 768 x 576, 32 bpp (PAL) */
    768, 576, 768, 576, 0, 0, 32, 0,
    { 16, 8, 0 }, { 8, 8, 0 }, { 0, 8, 0 }, { 24, 8, 0 },
    0, FB_ACTIVATE_NOW, -1, -1, FB_ACCEL_NONE,
    33333, 10, 102, 10, 5, 80, 34, FB_SYNC_COMP_HIGH_ACT, 0
    }, {
    /* 768 x 480, 32 bpp (NTSC - not supported yet */
    768, 480, 768, 480, 0, 0, 32, 0,
    { 16, 8, 0 }, { 8, 8, 0 }, { 0, 8, 0 }, { 24, 8, 0 },
    0, FB_ACTIVATE_NOW, -1, -1, FB_ACCEL_NONE,
    33333, 10, 102, 10, 5, 80, 34, FB_SYNC_COMP_HIGH_ACT, 0
    }
};

    /*
     *  Interface used by the world
     */

static int fm2fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                           u_int transp, struct fb_info *info);
static int fm2fb_blank(int blank, struct fb_info *info);

static struct fb_ops fm2fb_ops = {
    .owner      = THIS_MODULE,
    .fb_setcolreg   = fm2fb_setcolreg,
    .fb_blank   = fm2fb_blank,
    .fb_fillrect    = cfb_fillrect,
    .fb_copyarea    = cfb_copyarea,
    .fb_imageblit   = cfb_imageblit,
};

    /*
     *  Blank the display.
     */
static int fm2fb_blank(int blank, struct fb_info *info)
{
    unsigned char t = FRAMEMASTER_ROM;

    if (!blank)
        t |= FRAMEMASTER_ENABLE | FRAMEMASTER_NOLACE;
    fm2fb_reg[0] = t;
    return 0;
}

    /*
     *  Set a single color register. The values supplied are already
     *  rounded down to the hardware's capabilities (according to the
     *  entries in the var structure). Return != 0 for invalid regno.
     */
static int fm2fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                         u_int transp, struct fb_info *info)
{
    if (regno < 16) {
        red >>= 8;
        green >>= 8;
        blue >>= 8;

        ((u32*)(info->pseudo_palette))[regno] = (red << 16) |
            (green << 8) | blue;
    }

    return 0;
}

    /*
     *  Initialisation
     */

static int __devinit fm2fb_probe(struct zorro_dev *z,
                 const struct zorro_device_id *id);

static struct zorro_device_id fm2fb_devices[] __devinitdata = {
    { ZORRO_PROD_BSC_FRAMEMASTER_II },
    { ZORRO_PROD_HELFRICH_RAINBOW_II },
    { 0 }
};
MODULE_DEVICE_TABLE(zorro, fm2fb_devices);

static struct zorro_driver fm2fb_driver = {
    .name       = "fm2fb",
    .id_table   = fm2fb_devices,
    .probe      = fm2fb_probe,
};

static int __devinit fm2fb_probe(struct zorro_dev *z,
                 const struct zorro_device_id *id)
{
    struct fb_info *info;
    unsigned long *ptr;
    int is_fm;
    int x, y;

    is_fm = z->id == ZORRO_PROD_BSC_FRAMEMASTER_II;

    if (!zorro_request_device(z,"fm2fb"))
        return -ENXIO;

    info = framebuffer_alloc(16 * sizeof(u32), &z->dev);
    if (!info) {
        zorro_release_device(z);
        return -ENOMEM;
    }

    if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
        framebuffer_release(info);
        zorro_release_device(z);
        return -ENOMEM;
    }

    /* assigning memory to kernel space */
    fb_fix.smem_start = zorro_resource_start(z);
    info->screen_base = ioremap(fb_fix.smem_start, FRAMEMASTER_SIZE);
    fb_fix.mmio_start = fb_fix.smem_start + FRAMEMASTER_REG;
    fm2fb_reg  = (unsigned char *)(info->screen_base+FRAMEMASTER_REG);

    strcpy(fb_fix.id, is_fm ? "FrameMaster II" : "Rainbow II");

    /* make EBU color bars on display */
    ptr = (unsigned long *)fb_fix.smem_start;
    for (y = 0; y < 576; y++) {
        for (x = 0; x < 96; x++) *ptr++ = 0xffffff;/* white */
        for (x = 0; x < 96; x++) *ptr++ = 0xffff00;/* yellow */
        for (x = 0; x < 96; x++) *ptr++ = 0x00ffff;/* cyan */
        for (x = 0; x < 96; x++) *ptr++ = 0x00ff00;/* green */
        for (x = 0; x < 96; x++) *ptr++ = 0xff00ff;/* magenta */
        for (x = 0; x < 96; x++) *ptr++ = 0xff0000;/* red */
        for (x = 0; x < 96; x++) *ptr++ = 0x0000ff;/* blue */
        for (x = 0; x < 96; x++) *ptr++ = 0x000000;/* black */
    }
    fm2fb_blank(0, info);

    if (fm2fb_mode == -1)
        fm2fb_mode = FM2FB_MODE_PAL;

    info->fbops = &fm2fb_ops;
    info->var = fb_var_modes[fm2fb_mode];
    info->pseudo_palette = info->par;
    info->par = NULL;
    info->fix = fb_fix;
    info->flags = FBINFO_DEFAULT;

    if (register_framebuffer(info) < 0) {
        fb_dealloc_cmap(&info->cmap);
        iounmap(info->screen_base);
        framebuffer_release(info);
        zorro_release_device(z);
        return -EINVAL;
    }
    printk("fb%d: %s frame buffer device\n", info->node, fb_fix.id);
    return 0;
}

int __init fm2fb_setup(char *options)
{
    char *this_opt;

    if (!options || !*options)
        return 0;

    while ((this_opt = strsep(&options, ",")) != NULL) {
        if (!strncmp(this_opt, "pal", 3))
            fm2fb_mode = FM2FB_MODE_PAL;
        else if (!strncmp(this_opt, "ntsc", 4))
            fm2fb_mode = FM2FB_MODE_NTSC;
    }
    return 0;
}

int __init fm2fb_init(void)
{
    char *option = NULL;

    if (fb_get_options("fm2fb", &option))
        return -ENODEV;
    fm2fb_setup(option);
    return zorro_register_driver(&fm2fb_driver);
}

module_init(fm2fb_init);
MODULE_LICENSE("GPL");