mdacon.c

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/*
 *  linux/drivers/video/mdacon.c -- Low level MDA based console driver
 *
 *  (c) 1998 Andrew Apted <[email protected]>
 *
 *      including portions (c) 1995-1998 Patrick Caulfield.
 *
 *      slight improvements (c) 2000 Edward Betts <[email protected]>
 *
 *  This file is based on the VGA console driver (vgacon.c):
 *  
 *  Created 28 Sep 1997 by Geert Uytterhoeven
 *
 *  Rewritten by Martin Mares <[email protected]>, July 1998
 *
 *  and on the old console.c, vga.c and vesa_blank.c drivers:
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *              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.
 *
 *  Changelog:
 *  Paul G. (03/2001) Fix mdacon= boot prompt to use __setup().
 */

#include <linux/types.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/console.h>
#include <linux/string.h>
#include <linux/kd.h>
#include <linux/vt_kern.h>
#include <linux/vt_buffer.h>
#include <linux/selection.h>
#include <linux/spinlock.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/init.h>

#include <asm/io.h>
#include <asm/vga.h>

static DEFINE_SPINLOCK(mda_lock);

/* description of the hardware layout */

static unsigned long    mda_vram_base;      /* Base of video memory */
static unsigned long    mda_vram_len;       /* Size of video memory */
static unsigned int mda_num_columns;    /* Number of text columns */
static unsigned int mda_num_lines;      /* Number of text lines */

static unsigned int mda_index_port;     /* Register select port */
static unsigned int mda_value_port;     /* Register value port */
static unsigned int mda_mode_port;      /* Mode control port */
static unsigned int mda_status_port;    /* Status and Config port */
static unsigned int mda_gfx_port;       /* Graphics control port */

/* current hardware state */

static int  mda_cursor_loc=-1;
static int  mda_cursor_size_from=-1;
static int  mda_cursor_size_to=-1;

static enum { TYPE_MDA, TYPE_HERC, TYPE_HERCPLUS, TYPE_HERCCOLOR } mda_type;
static char *mda_type_name;

/* console information */

static int  mda_first_vc = 13;
static int  mda_last_vc  = 16;

static struct vc_data   *mda_display_fg = NULL;

module_param(mda_first_vc, int, 0);
MODULE_PARM_DESC(mda_first_vc, "First virtual console. Default: 13");
module_param(mda_last_vc, int, 0);
MODULE_PARM_DESC(mda_last_vc, "Last virtual console. Default: 16");

/* MDA register values
 */

#define MDA_CURSOR_BLINKING 0x00
#define MDA_CURSOR_OFF      0x20
#define MDA_CURSOR_SLOWBLINK    0x60

#define MDA_MODE_GRAPHICS   0x02
#define MDA_MODE_VIDEO_EN   0x08
#define MDA_MODE_BLINK_EN   0x20
#define MDA_MODE_GFX_PAGE1  0x80

#define MDA_STATUS_HSYNC    0x01
#define MDA_STATUS_VSYNC    0x80
#define MDA_STATUS_VIDEO    0x08

#define MDA_CONFIG_COL132   0x08
#define MDA_GFX_MODE_EN     0x01
#define MDA_GFX_PAGE_EN     0x02


/*
 * MDA could easily be classified as "pre-dinosaur hardware".
 */

static void write_mda_b(unsigned int val, unsigned char reg)
{
    unsigned long flags;

    spin_lock_irqsave(&mda_lock, flags);    

    outb_p(reg, mda_index_port); 
    outb_p(val, mda_value_port);

    spin_unlock_irqrestore(&mda_lock, flags);
}

static void write_mda_w(unsigned int val, unsigned char reg)
{
    unsigned long flags;

    spin_lock_irqsave(&mda_lock, flags);

    outb_p(reg,   mda_index_port); outb_p(val >> 8,   mda_value_port);
    outb_p(reg+1, mda_index_port); outb_p(val & 0xff, mda_value_port);

    spin_unlock_irqrestore(&mda_lock, flags);
}

#ifdef TEST_MDA_B
static int test_mda_b(unsigned char val, unsigned char reg)
{
    unsigned long flags;

    spin_lock_irqsave(&mda_lock, flags);

    outb_p(reg, mda_index_port); 
    outb  (val, mda_value_port);

    udelay(20); val = (inb_p(mda_value_port) == val);

    spin_unlock_irqrestore(&mda_lock, flags);
    return val;
}
#endif

static inline void mda_set_cursor(unsigned int location) 
{
    if (mda_cursor_loc == location)
        return;

    write_mda_w(location >> 1, 0x0e);

    mda_cursor_loc = location;
}

static inline void mda_set_cursor_size(int from, int to)
{
    if (mda_cursor_size_from==from && mda_cursor_size_to==to)
        return;
    
    if (from > to) {
        write_mda_b(MDA_CURSOR_OFF, 0x0a);  /* disable cursor */
    } else {
        write_mda_b(from, 0x0a);    /* cursor start */
        write_mda_b(to,   0x0b);    /* cursor end */
    }

    mda_cursor_size_from = from;
    mda_cursor_size_to   = to;
}


#ifndef MODULE
static int __init mdacon_setup(char *str)
{
    /* command line format: mdacon=<first>,<last> */

    int ints[3];

    str = get_options(str, ARRAY_SIZE(ints), ints);

    if (ints[0] < 2)
        return 0;

    if (ints[1] < 1 || ints[1] > MAX_NR_CONSOLES || 
        ints[2] < 1 || ints[2] > MAX_NR_CONSOLES)
        return 0;

    mda_first_vc = ints[1];
    mda_last_vc  = ints[2];
    return 1;
}

__setup("mdacon=", mdacon_setup);
#endif

static int mda_detect(void)
{
    int count=0;
    u16 *p, p_save;
    u16 *q, q_save;

    /* do a memory check */

    p = (u16 *) mda_vram_base;
    q = (u16 *) (mda_vram_base + 0x01000);

    p_save = scr_readw(p); q_save = scr_readw(q);

    scr_writew(0xAA55, p); if (scr_readw(p) == 0xAA55) count++;
    scr_writew(0x55AA, p); if (scr_readw(p) == 0x55AA) count++;
    scr_writew(p_save, p);

    if (count != 2) {
        return 0;
    }

    /* check if we have 4K or 8K */

    scr_writew(0xA55A, q); scr_writew(0x0000, p);
    if (scr_readw(q) == 0xA55A) count++;
    
    scr_writew(0x5AA5, q); scr_writew(0x0000, p);
    if (scr_readw(q) == 0x5AA5) count++;

    scr_writew(p_save, p); scr_writew(q_save, q);
    
    if (count == 4) {
        mda_vram_len = 0x02000;
    }
    
    /* Ok, there is definitely a card registering at the correct
     * memory location, so now we do an I/O port test.
     */

#ifdef TEST_MDA_B
    /* Edward: These two mess `tests' mess up my cursor on bootup */

    /* cursor low register */
    if (! test_mda_b(0x66, 0x0f)) {
        return 0;
    }

    /* cursor low register */
    if (! test_mda_b(0x99, 0x0f)) {
        return 0;
    }
#endif

    /* See if the card is a Hercules, by checking whether the vsync
     * bit of the status register is changing.  This test lasts for
     * approximately 1/10th of a second.
     */
    
    p_save = q_save = inb_p(mda_status_port) & MDA_STATUS_VSYNC;

    for (count=0; count < 50000 && p_save == q_save; count++) {
        q_save = inb(mda_status_port) & MDA_STATUS_VSYNC;
        udelay(2);
    }

    if (p_save != q_save) {
        switch (inb_p(mda_status_port) & 0x70) {
            case 0x10:
                mda_type = TYPE_HERCPLUS;
                mda_type_name = "HerculesPlus";
                break;
            case 0x50:
                mda_type = TYPE_HERCCOLOR;
                mda_type_name = "HerculesColor";
                break;
            default:
                mda_type = TYPE_HERC;
                mda_type_name = "Hercules";
                break;
        }
    }

    return 1;
}

static void mda_initialize(void)
{
    write_mda_b(97, 0x00);      /* horizontal total */
    write_mda_b(80, 0x01);      /* horizontal displayed */
    write_mda_b(82, 0x02);      /* horizontal sync pos */
    write_mda_b(15, 0x03);      /* horizontal sync width */

    write_mda_b(25, 0x04);      /* vertical total */
    write_mda_b(6,  0x05);      /* vertical total adjust */
    write_mda_b(25, 0x06);      /* vertical displayed */
    write_mda_b(25, 0x07);      /* vertical sync pos */

    write_mda_b(2,  0x08);      /* interlace mode */
    write_mda_b(13, 0x09);      /* maximum scanline */
    write_mda_b(12, 0x0a);      /* cursor start */
    write_mda_b(13, 0x0b);      /* cursor end */

    write_mda_w(0x0000, 0x0c);  /* start address */
    write_mda_w(0x0000, 0x0e);  /* cursor location */

    outb_p(MDA_MODE_VIDEO_EN | MDA_MODE_BLINK_EN, mda_mode_port);
    outb_p(0x00, mda_status_port);
    outb_p(0x00, mda_gfx_port);
}

static const char *mdacon_startup(void)
{
    mda_num_columns = 80;
    mda_num_lines   = 25;

    mda_vram_len  = 0x01000;
    mda_vram_base = VGA_MAP_MEM(0xb0000, mda_vram_len);

    mda_index_port  = 0x3b4;
    mda_value_port  = 0x3b5;
    mda_mode_port   = 0x3b8;
    mda_status_port = 0x3ba;
    mda_gfx_port    = 0x3bf;

    mda_type = TYPE_MDA;
    mda_type_name = "MDA";

    if (! mda_detect()) {
        printk("mdacon: MDA card not detected.\n");
        return NULL;
    }

    if (mda_type != TYPE_MDA) {
        mda_initialize();
    }

    /* cursor looks ugly during boot-up, so turn it off */
    mda_set_cursor(mda_vram_len - 1);

    printk("mdacon: %s with %ldK of memory detected.\n",
        mda_type_name, mda_vram_len/1024);

    return "MDA-2";
}

static void mdacon_init(struct vc_data *c, int init)
{
    c->vc_complement_mask = 0x0800;  /* reverse video */
    c->vc_display_fg = &mda_display_fg;

    if (init) {
        c->vc_cols = mda_num_columns;
        c->vc_rows = mda_num_lines;
    } else
        vc_resize(c, mda_num_columns, mda_num_lines);

    /* make the first MDA console visible */

    if (mda_display_fg == NULL)
        mda_display_fg = c;
}

static void mdacon_deinit(struct vc_data *c)
{
    /* con_set_default_unimap(c->vc_num); */

    if (mda_display_fg == c)
        mda_display_fg = NULL;
}

static inline u16 mda_convert_attr(u16 ch)
{
    u16 attr = 0x0700;

    /* Underline and reverse-video are mutually exclusive on MDA.
     * Since reverse-video is used for cursors and selected areas,
     * it takes precedence. 
     */

    if (ch & 0x0800)    attr = 0x7000;  /* reverse */
    else if (ch & 0x0400)   attr = 0x0100;  /* underline */

    return ((ch & 0x0200) << 2) |       /* intensity */ 
        (ch & 0x8000) |         /* blink */ 
        (ch & 0x00ff) | attr;
}

static u8 mdacon_build_attr(struct vc_data *c, u8 color, u8 intensity, 
                u8 blink, u8 underline, u8 reverse, u8 italic)
{
    /* The attribute is just a bit vector:
     *
     *  Bit 0..1 : intensity (0..2)
     *  Bit 2    : underline
     *  Bit 3    : reverse
     *  Bit 7    : blink
     */

    return (intensity & 3) |
        ((underline & 1) << 2) |
        ((reverse   & 1) << 3) |
        (!!italic << 4) |
        ((blink     & 1) << 7);
}

static void mdacon_invert_region(struct vc_data *c, u16 *p, int count)
{
    for (; count > 0; count--) {
        scr_writew(scr_readw(p) ^ 0x0800, p);
        p++;
    }
}

#define MDA_ADDR(x,y)  ((u16 *) mda_vram_base + (y)*mda_num_columns + (x))

static void mdacon_putc(struct vc_data *c, int ch, int y, int x)
{
    scr_writew(mda_convert_attr(ch), MDA_ADDR(x, y));
}

static void mdacon_putcs(struct vc_data *c, const unsigned short *s,
                 int count, int y, int x)
{
    u16 *dest = MDA_ADDR(x, y);

    for (; count > 0; count--) {
        scr_writew(mda_convert_attr(scr_readw(s++)), dest++);
    }
}

static void mdacon_clear(struct vc_data *c, int y, int x, 
              int height, int width)
{
    u16 *dest = MDA_ADDR(x, y);
    u16 eattr = mda_convert_attr(c->vc_video_erase_char);

    if (width <= 0 || height <= 0)
        return;

    if (x==0 && width==mda_num_columns) {
        scr_memsetw(dest, eattr, height*width*2);
    } else {
        for (; height > 0; height--, dest+=mda_num_columns)
            scr_memsetw(dest, eattr, width*2);
    }
}
                        
static void mdacon_bmove(struct vc_data *c, int sy, int sx, 
             int dy, int dx, int height, int width)
{
    u16 *src, *dest;

    if (width <= 0 || height <= 0)
        return;
        
    if (sx==0 && dx==0 && width==mda_num_columns) {
        scr_memmovew(MDA_ADDR(0,dy), MDA_ADDR(0,sy), height*width*2);

    } else if (dy < sy || (dy == sy && dx < sx)) {
        src  = MDA_ADDR(sx, sy);
        dest = MDA_ADDR(dx, dy);

        for (; height > 0; height--) {
            scr_memmovew(dest, src, width*2);
            src  += mda_num_columns;
            dest += mda_num_columns;
        }
    } else {
        src  = MDA_ADDR(sx, sy+height-1);
        dest = MDA_ADDR(dx, dy+height-1);

        for (; height > 0; height--) {
            scr_memmovew(dest, src, width*2);
            src  -= mda_num_columns;
            dest -= mda_num_columns;
        }
    }
}

static int mdacon_switch(struct vc_data *c)
{
    return 1;   /* redrawing needed */
}

static int mdacon_set_palette(struct vc_data *c, unsigned char *table)
{
    return -EINVAL;
}

static int mdacon_blank(struct vc_data *c, int blank, int mode_switch)
{
    if (mda_type == TYPE_MDA) {
        if (blank) 
            scr_memsetw((void *)mda_vram_base, 
                mda_convert_attr(c->vc_video_erase_char),
                c->vc_screenbuf_size);
        /* Tell console.c that it has to restore the screen itself */
        return 1;
    } else {
        if (blank)
            outb_p(0x00, mda_mode_port);    /* disable video */
        else
            outb_p(MDA_MODE_VIDEO_EN | MDA_MODE_BLINK_EN, 
                mda_mode_port);
        return 0;
    }
}

static int mdacon_scrolldelta(struct vc_data *c, int lines)
{
    return 0;
}

static void mdacon_cursor(struct vc_data *c, int mode)
{
    if (mode == CM_ERASE) {
        mda_set_cursor(mda_vram_len - 1);
        return;
    }

    mda_set_cursor(c->vc_y*mda_num_columns*2 + c->vc_x*2);

    switch (c->vc_cursor_type & 0x0f) {

        case CUR_LOWER_THIRD:   mda_set_cursor_size(10, 13); break;
        case CUR_LOWER_HALF:    mda_set_cursor_size(7,  13); break;
        case CUR_TWO_THIRDS:    mda_set_cursor_size(4,  13); break;
        case CUR_BLOCK:     mda_set_cursor_size(1,  13); break;
        case CUR_NONE:      mda_set_cursor_size(14, 13); break;
        default:        mda_set_cursor_size(12, 13); break;
    }
}

static int mdacon_scroll(struct vc_data *c, int t, int b, int dir, int lines)
{
    u16 eattr = mda_convert_attr(c->vc_video_erase_char);

    if (!lines)
        return 0;

    if (lines > c->vc_rows)   /* maximum realistic size */
        lines = c->vc_rows;

    switch (dir) {

    case SM_UP:
        scr_memmovew(MDA_ADDR(0,t), MDA_ADDR(0,t+lines),
                (b-t-lines)*mda_num_columns*2);
        scr_memsetw(MDA_ADDR(0,b-lines), eattr,
                lines*mda_num_columns*2);
        break;

    case SM_DOWN:
        scr_memmovew(MDA_ADDR(0,t+lines), MDA_ADDR(0,t),
                (b-t-lines)*mda_num_columns*2);
        scr_memsetw(MDA_ADDR(0,t), eattr, lines*mda_num_columns*2);
        break;
    }

    return 0;
}


/*
 *  The console `switch' structure for the MDA based console
 */

static const struct consw mda_con = {
    .owner =        THIS_MODULE,
    .con_startup =      mdacon_startup,
    .con_init =     mdacon_init,
    .con_deinit =       mdacon_deinit,
    .con_clear =        mdacon_clear,
    .con_putc =     mdacon_putc,
    .con_putcs =        mdacon_putcs,
    .con_cursor =       mdacon_cursor,
    .con_scroll =       mdacon_scroll,
    .con_bmove =        mdacon_bmove,
    .con_switch =       mdacon_switch,
    .con_blank =        mdacon_blank,
    .con_set_palette =  mdacon_set_palette,
    .con_scrolldelta =  mdacon_scrolldelta,
    .con_build_attr =   mdacon_build_attr,
    .con_invert_region =    mdacon_invert_region,
};

int __init mda_console_init(void)
{
    if (mda_first_vc > mda_last_vc)
        return 1;

    return take_over_console(&mda_con, mda_first_vc-1, mda_last_vc-1, 0);
}

static void __exit mda_console_exit(void)
{
    give_up_console(&mda_con);
}

module_init(mda_console_init);
module_exit(mda_console_exit);

MODULE_LICENSE("GPL");