hgafb.c

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/*
 * linux/drivers/video/hgafb.c -- Hercules graphics adaptor frame buffer device
 * 
 *      Created 25 Nov 1999 by Ferenc Bakonyi ([email protected])
 *      Based on skeletonfb.c by Geert Uytterhoeven and
 *               mdacon.c by Andrew Apted
 *
 * History:
 *
 * - Revision 0.1.8 (23 Oct 2002): Ported to new framebuffer api.
 * 
 * - Revision 0.1.7 (23 Jan 2001): fix crash resulting from MDA only cards 
 *                 being detected as Hercules.   (Paul G.)
 * - Revision 0.1.6 (17 Aug 2000): new style structs
 *                                 documentation
 * - Revision 0.1.5 (13 Mar 2000): spinlocks instead of saveflags();cli();etc
 *                                 minor fixes
 * - Revision 0.1.4 (24 Jan 2000): fixed a bug in hga_card_detect() for 
 *                                  HGA-only systems
 * - Revision 0.1.3 (22 Jan 2000): modified for the new fb_info structure
 *                                 screen is cleared after rmmod
 *                                 virtual resolutions
 *                                 module parameter 'nologo={0|1}'
 *                                 the most important: boot logo :)
 * - Revision 0.1.0  (6 Dec 1999): faster scrolling and minor fixes
 * - First release  (25 Nov 1999)
 *
 * 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/kernel.h>
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <asm/io.h>
#include <asm/vga.h>

#if 0
#define DPRINTK(args...) printk(KERN_DEBUG __FILE__": " ##args)
#else
#define DPRINTK(args...)
#endif

#if 0
#define CHKINFO(ret) if (info != &fb_info) { printk(KERN_DEBUG __FILE__": This should never happen, line:%d \n", __LINE__); return ret; }
#else
#define CHKINFO(ret)
#endif

/* Description of the hardware layout */

static void __iomem *hga_vram;          /* Base of video memory */
static unsigned long hga_vram_len;      /* Size of video memory */

#define HGA_ROWADDR(row) ((row%4)*8192 + (row>>2)*90)
#define HGA_TXT         0
#define HGA_GFX         1

static inline u8 __iomem * rowaddr(struct fb_info *info, u_int row)
{
    return info->screen_base + HGA_ROWADDR(row);
}

static int hga_mode = -1;           /* 0 = txt, 1 = gfx mode */

static enum { TYPE_HERC, TYPE_HERCPLUS, TYPE_HERCCOLOR } hga_type;
static char *hga_type_name;

#define HGA_INDEX_PORT      0x3b4       /* Register select port */
#define HGA_VALUE_PORT      0x3b5       /* Register value port */
#define HGA_MODE_PORT       0x3b8       /* Mode control port */
#define HGA_STATUS_PORT     0x3ba       /* Status and Config port */
#define HGA_GFX_PORT        0x3bf       /* Graphics control port */

/* HGA register values */

#define HGA_CURSOR_BLINKING 0x00
#define HGA_CURSOR_OFF      0x20
#define HGA_CURSOR_SLOWBLINK    0x60

#define HGA_MODE_GRAPHICS   0x02
#define HGA_MODE_VIDEO_EN   0x08
#define HGA_MODE_BLINK_EN   0x20
#define HGA_MODE_GFX_PAGE1  0x80

#define HGA_STATUS_HSYNC    0x01
#define HGA_STATUS_VSYNC    0x80
#define HGA_STATUS_VIDEO    0x08

#define HGA_CONFIG_COL132   0x08
#define HGA_GFX_MODE_EN     0x01
#define HGA_GFX_PAGE_EN     0x02

/* Global locks */

static DEFINE_SPINLOCK(hga_reg_lock);

/* Framebuffer driver structures */

static struct fb_var_screeninfo hga_default_var __devinitdata = {
    .xres       = 720,
    .yres       = 348,
    .xres_virtual   = 720,
    .yres_virtual   = 348,
    .bits_per_pixel = 1,
    .red        = {0, 1, 0},
    .green      = {0, 1, 0},
    .blue       = {0, 1, 0},
    .transp     = {0, 0, 0},
    .height     = -1,
    .width      = -1,
};

static struct fb_fix_screeninfo hga_fix __devinitdata = {
    .id         = "HGA",
    .type       = FB_TYPE_PACKED_PIXELS,    /* (not sure) */
    .visual     = FB_VISUAL_MONO10,
    .xpanstep   = 8,
    .ypanstep   = 8,
    .line_length    = 90,
    .accel      = FB_ACCEL_NONE
};

/* Don't assume that tty1 will be the initial current console. */
static int release_io_port = 0;
static int release_io_ports = 0;
static bool nologo = 0;

/* -------------------------------------------------------------------------
 *
 * Low level hardware functions
 *
 * ------------------------------------------------------------------------- */

static void write_hga_b(unsigned int val, unsigned char reg)
{
    outb_p(reg, HGA_INDEX_PORT); 
    outb_p(val, HGA_VALUE_PORT);
}

static void write_hga_w(unsigned int val, unsigned char reg)
{
    outb_p(reg,   HGA_INDEX_PORT); outb_p(val >> 8,   HGA_VALUE_PORT);
    outb_p(reg+1, HGA_INDEX_PORT); outb_p(val & 0xff, HGA_VALUE_PORT);
}

static int test_hga_b(unsigned char val, unsigned char reg)
{
    outb_p(reg, HGA_INDEX_PORT); 
    outb  (val, HGA_VALUE_PORT);
    udelay(20); val = (inb_p(HGA_VALUE_PORT) == val);
    return val;
}

static void hga_clear_screen(void)
{
    unsigned char fillchar = 0xbf; /* magic */
    unsigned long flags;

    spin_lock_irqsave(&hga_reg_lock, flags);
    if (hga_mode == HGA_TXT)
        fillchar = ' ';
    else if (hga_mode == HGA_GFX)
        fillchar = 0x00;
    spin_unlock_irqrestore(&hga_reg_lock, flags);
    if (fillchar != 0xbf)
        memset_io(hga_vram, fillchar, hga_vram_len);
}

static void hga_txt_mode(void)
{
    unsigned long flags;

    spin_lock_irqsave(&hga_reg_lock, flags);
    outb_p(HGA_MODE_VIDEO_EN | HGA_MODE_BLINK_EN, HGA_MODE_PORT);
    outb_p(0x00, HGA_GFX_PORT);
    outb_p(0x00, HGA_STATUS_PORT);

    write_hga_b(0x61, 0x00);    /* horizontal total */
    write_hga_b(0x50, 0x01);    /* horizontal displayed */
    write_hga_b(0x52, 0x02);    /* horizontal sync pos */
    write_hga_b(0x0f, 0x03);    /* horizontal sync width */

    write_hga_b(0x19, 0x04);    /* vertical total */
    write_hga_b(0x06, 0x05);    /* vertical total adjust */
    write_hga_b(0x19, 0x06);    /* vertical displayed */
    write_hga_b(0x19, 0x07);    /* vertical sync pos */

    write_hga_b(0x02, 0x08);    /* interlace mode */
    write_hga_b(0x0d, 0x09);    /* maximum scanline */
    write_hga_b(0x0c, 0x0a);    /* cursor start */
    write_hga_b(0x0d, 0x0b);    /* cursor end */

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

    hga_mode = HGA_TXT;
    spin_unlock_irqrestore(&hga_reg_lock, flags);
}

static void hga_gfx_mode(void)
{
    unsigned long flags;

    spin_lock_irqsave(&hga_reg_lock, flags);
    outb_p(0x00, HGA_STATUS_PORT);
    outb_p(HGA_GFX_MODE_EN, HGA_GFX_PORT);
    outb_p(HGA_MODE_VIDEO_EN | HGA_MODE_GRAPHICS, HGA_MODE_PORT);

    write_hga_b(0x35, 0x00);    /* horizontal total */
    write_hga_b(0x2d, 0x01);    /* horizontal displayed */
    write_hga_b(0x2e, 0x02);    /* horizontal sync pos */
    write_hga_b(0x07, 0x03);    /* horizontal sync width */

    write_hga_b(0x5b, 0x04);    /* vertical total */
    write_hga_b(0x02, 0x05);    /* vertical total adjust */
    write_hga_b(0x57, 0x06);    /* vertical displayed */
    write_hga_b(0x57, 0x07);    /* vertical sync pos */

    write_hga_b(0x02, 0x08);    /* interlace mode */
    write_hga_b(0x03, 0x09);    /* maximum scanline */
    write_hga_b(0x00, 0x0a);    /* cursor start */
    write_hga_b(0x00, 0x0b);    /* cursor end */

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

    hga_mode = HGA_GFX;
    spin_unlock_irqrestore(&hga_reg_lock, flags);
}

static void hga_show_logo(struct fb_info *info)
{
/*
    void __iomem *dest = hga_vram;
    char *logo = linux_logo_bw;
    int x, y;
    
    for (y = 134; y < 134 + 80 ; y++) * this needs some cleanup *
        for (x = 0; x < 10 ; x++)
            writeb(~*(logo++),(dest + HGA_ROWADDR(y) + x + 40));
*/
}

static void hga_pan(unsigned int xoffset, unsigned int yoffset)
{
    unsigned int base;
    unsigned long flags;
    
    base = (yoffset / 8) * 90 + xoffset;
    spin_lock_irqsave(&hga_reg_lock, flags);
    write_hga_w(base, 0x0c);    /* start address */
    spin_unlock_irqrestore(&hga_reg_lock, flags);
    DPRINTK("hga_pan: base:%d\n", base);
}

static void hga_blank(int blank_mode)
{
    unsigned long flags;

    spin_lock_irqsave(&hga_reg_lock, flags);
    if (blank_mode) {
        outb_p(0x00, HGA_MODE_PORT);    /* disable video */
    } else {
        outb_p(HGA_MODE_VIDEO_EN | HGA_MODE_GRAPHICS, HGA_MODE_PORT);
    }
    spin_unlock_irqrestore(&hga_reg_lock, flags);
}

static int __devinit hga_card_detect(void)
{
    int count = 0;
    void __iomem *p, *q;
    unsigned short p_save, q_save;

    hga_vram_len  = 0x08000;

    hga_vram = ioremap(0xb0000, hga_vram_len);

    if (request_region(0x3b0, 12, "hgafb"))
        release_io_ports = 1;
    if (request_region(0x3bf, 1, "hgafb"))
        release_io_port = 1;

    /* do a memory check */

    p = hga_vram;
    q = hga_vram + 0x01000;

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

    writew(0xaa55, p); if (readw(p) == 0xaa55) count++;
    writew(0x55aa, p); if (readw(p) == 0x55aa) count++;
    writew(p_save, p);

    if (count != 2)
        goto error;

    /* Ok, there is definitely a card registering at the correct
     * memory location, so now we do an I/O port test.
     */
    
    if (!test_hga_b(0x66, 0x0f))        /* cursor low register */
        goto error;

    if (!test_hga_b(0x99, 0x0f))     /* cursor low register */
        goto error;

    /* 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(HGA_STATUS_PORT) & HGA_STATUS_VSYNC;

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

    if (p_save == q_save) 
        goto error;

    switch (inb_p(HGA_STATUS_PORT) & 0x70) {
        case 0x10:
            hga_type = TYPE_HERCPLUS;
            hga_type_name = "HerculesPlus";
            break;
        case 0x50:
            hga_type = TYPE_HERCCOLOR;
            hga_type_name = "HerculesColor";
            break;
        default:
            hga_type = TYPE_HERC;
            hga_type_name = "Hercules";
            break;
    }
    return 1;
error:
    if (release_io_ports)
        release_region(0x3b0, 12);
    if (release_io_port)
        release_region(0x3bf, 1);
    return 0;
}

static int hgafb_open(struct fb_info *info, int init)
{
    hga_gfx_mode();
    hga_clear_screen();
    if (!nologo) hga_show_logo(info);
    return 0;
}

static int hgafb_release(struct fb_info *info, int init)
{
    hga_txt_mode();
    hga_clear_screen();
    return 0;
}

static int hgafb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
               u_int transp, struct fb_info *info)
{
    if (regno > 1)
        return 1;
    return 0;
}

static int hgafb_pan_display(struct fb_var_screeninfo *var,
                 struct fb_info *info)
{
    if (var->vmode & FB_VMODE_YWRAP) {
        if (var->yoffset < 0 || 
            var->yoffset >= info->var.yres_virtual ||
            var->xoffset)
            return -EINVAL;
    } else {
        if (var->xoffset + info->var.xres > info->var.xres_virtual
         || var->yoffset + info->var.yres > info->var.yres_virtual
         || var->yoffset % 8)
            return -EINVAL;
    }

    hga_pan(var->xoffset, var->yoffset);
    return 0;
}

static int hgafb_blank(int blank_mode, struct fb_info *info)
{
    hga_blank(blank_mode);
    return 0;
}

/*
 * Accel functions
 */
static void hgafb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
    u_int rows, y;
    u8 __iomem *dest;

    y = rect->dy;

    for (rows = rect->height; rows--; y++) {
        dest = rowaddr(info, y) + (rect->dx >> 3);
        switch (rect->rop) {
        case ROP_COPY:
            memset_io(dest, rect->color, (rect->width >> 3));
            break;
        case ROP_XOR:
            fb_writeb(~(fb_readb(dest)), dest);
            break;
        }
    }
}

static void hgafb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
{
    u_int rows, y1, y2;
    u8 __iomem *src;
    u8 __iomem *dest;

    if (area->dy <= area->sy) {
        y1 = area->sy;
        y2 = area->dy;

        for (rows = area->height; rows--; ) {
            src = rowaddr(info, y1) + (area->sx >> 3);
            dest = rowaddr(info, y2) + (area->dx >> 3);
            memmove(dest, src, (area->width >> 3));
            y1++;
            y2++;
        }
    } else {
        y1 = area->sy + area->height - 1;
        y2 = area->dy + area->height - 1;

        for (rows = area->height; rows--;) {
            src = rowaddr(info, y1) + (area->sx >> 3);
            dest = rowaddr(info, y2) + (area->dx >> 3);
            memmove(dest, src, (area->width >> 3));
            y1--;
            y2--;
        }
    }
}

static void hgafb_imageblit(struct fb_info *info, const struct fb_image *image)
{
    u8 __iomem *dest;
    u8 *cdat = (u8 *) image->data;
    u_int rows, y = image->dy;
    u_int x;
    u8 d;

    for (rows = image->height; rows--; y++) {
        for (x = 0; x < image->width; x+= 8) {
            d = *cdat++;
            dest = rowaddr(info, y) + ((image->dx + x)>> 3);
            fb_writeb(d, dest);
        }
    }
}

static struct fb_ops hgafb_ops = {
    .owner      = THIS_MODULE,
    .fb_open    = hgafb_open,
    .fb_release = hgafb_release,
    .fb_setcolreg   = hgafb_setcolreg,
    .fb_pan_display = hgafb_pan_display,
    .fb_blank   = hgafb_blank,
    .fb_fillrect    = hgafb_fillrect,
    .fb_copyarea    = hgafb_copyarea,
    .fb_imageblit   = hgafb_imageblit,
};
        
/* ------------------------------------------------------------------------- *
 *
 * Functions in fb_info
 * 
 * ------------------------------------------------------------------------- */

/* ------------------------------------------------------------------------- */
    
    /*
     *  Initialization
     */

static int __devinit hgafb_probe(struct platform_device *pdev)
{
    struct fb_info *info;

    if (! hga_card_detect()) {
        printk(KERN_INFO "hgafb: HGA card not detected.\n");
        if (hga_vram)
            iounmap(hga_vram);
        return -EINVAL;
    }

    printk(KERN_INFO "hgafb: %s with %ldK of memory detected.\n",
        hga_type_name, hga_vram_len/1024);

    info = framebuffer_alloc(0, &pdev->dev);
    if (!info) {
        iounmap(hga_vram);
        return -ENOMEM;
    }

    hga_fix.smem_start = (unsigned long)hga_vram;
    hga_fix.smem_len = hga_vram_len;

    info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
    info->var = hga_default_var;
    info->fix = hga_fix;
    info->monspecs.hfmin = 0;
    info->monspecs.hfmax = 0;
    info->monspecs.vfmin = 10000;
    info->monspecs.vfmax = 10000;
    info->monspecs.dpms = 0;
    info->fbops = &hgafb_ops;
    info->screen_base = hga_vram;

        if (register_framebuffer(info) < 0) {
        framebuffer_release(info);
        iounmap(hga_vram);
        return -EINVAL;
    }

        printk(KERN_INFO "fb%d: %s frame buffer device\n",
               info->node, info->fix.id);
    platform_set_drvdata(pdev, info);
    return 0;
}

static int __devexit hgafb_remove(struct platform_device *pdev)
{
    struct fb_info *info = platform_get_drvdata(pdev);

    hga_txt_mode();
    hga_clear_screen();

    if (info) {
        unregister_framebuffer(info);
        framebuffer_release(info);
    }

    iounmap(hga_vram);

    if (release_io_ports)
        release_region(0x3b0, 12);

    if (release_io_port)
        release_region(0x3bf, 1);

    return 0;
}

static struct platform_driver hgafb_driver = {
    .probe = hgafb_probe,
    .remove = __devexit_p(hgafb_remove),
    .driver = {
        .name = "hgafb",
    },
};

static struct platform_device *hgafb_device;

static int __init hgafb_init(void)
{
    int ret;

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

    ret = platform_driver_register(&hgafb_driver);

    if (!ret) {
        hgafb_device = platform_device_register_simple("hgafb", 0, NULL, 0);

        if (IS_ERR(hgafb_device)) {
            platform_driver_unregister(&hgafb_driver);
            ret = PTR_ERR(hgafb_device);
        }
    }

    return ret;
}

static void __exit hgafb_exit(void)
{
    platform_device_unregister(hgafb_device);
    platform_driver_unregister(&hgafb_driver);
}

/* -------------------------------------------------------------------------
 *
 *  Modularization
 *
 * ------------------------------------------------------------------------- */

MODULE_AUTHOR("Ferenc Bakonyi ([email protected])");
MODULE_DESCRIPTION("FBDev driver for Hercules Graphics Adaptor");
MODULE_LICENSE("GPL");

module_param(nologo, bool, 0);
MODULE_PARM_DESC(nologo, "Disables startup logo if != 0 (default=0)");
module_init(hgafb_init);
module_exit(hgafb_exit);