maxinefb.c

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/*
 *      linux/drivers/video/maxinefb.c
 *
 *  DECstation 5000/xx onboard framebuffer support ... derived from:
 *  "HP300 Topcat framebuffer support (derived from macfb of all things)
 *  Phil Blundell <[email protected]> 1998", the original code can be
 *      found in the file hpfb.c in the same directory.
 *
 *      DECstation related code Copyright (C) 1999,2000,2001 by
 *      Michael Engel <[email protected]> and
 *      Karsten Merker <[email protected]>.
 *      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.
 *
 */

/*
 * Changes:
 * 2001/01/27 removed debugging and testing code, fixed fb_ops
 *            initialization which had caused a crash before,
 *            general cleanup, first official release (KM)
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/fb.h>
#include <video/maxinefb.h>

/* bootinfo.h defines the machine type values, needed when checking */
/* whether are really running on a maxine, KM                       */
#include <asm/bootinfo.h>

static struct fb_info fb_info;

static struct fb_var_screeninfo maxinefb_defined = {
    .xres =     1024,
    .yres =     768,
    .xres_virtual = 1024,
    .yres_virtual = 768,
    .bits_per_pixel =8,
    .activate = FB_ACTIVATE_NOW,
    .height =   -1,
    .width =    -1,
    .vmode =    FB_VMODE_NONINTERLACED,
};

static struct fb_fix_screeninfo maxinefb_fix = {
    .id =       "Maxine",
    .smem_len = (1024*768),
    .type =     FB_TYPE_PACKED_PIXELS,
    .visual =   FB_VISUAL_PSEUDOCOLOR,
    .line_length =  1024,
};

/* Handle the funny Inmos RamDAC/video controller ... */

void maxinefb_ims332_write_register(int regno, register unsigned int val)
{
    register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
    unsigned char *wptr;

    wptr = regs + 0xa0000 + (regno << 4);
    *((volatile unsigned int *) (regs)) = (val >> 8) & 0xff00;
    *((volatile unsigned short *) (wptr)) = val;
}

unsigned int maxinefb_ims332_read_register(int regno)
{
    register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
    unsigned char *rptr;
    register unsigned int j, k;

    rptr = regs + 0x80000 + (regno << 4);
    j = *((volatile unsigned short *) rptr);
    k = *((volatile unsigned short *) regs);

    return (j & 0xffff) | ((k & 0xff00) << 8);
}

/* Set the palette */
static int maxinefb_setcolreg(unsigned regno, unsigned red, unsigned green,
                  unsigned blue, unsigned transp, struct fb_info *info)
{
    /* value to be written into the palette reg. */
    unsigned long hw_colorvalue = 0;

    if (regno > 255)
        return 1;

    red   >>= 8;    /* The cmap fields are 16 bits    */
    green >>= 8;    /* wide, but the harware colormap */
    blue  >>= 8;    /* registers are only 8 bits wide */

    hw_colorvalue = (blue << 16) + (green << 8) + (red);

    maxinefb_ims332_write_register(IMS332_REG_COLOR_PALETTE + regno,
                       hw_colorvalue);
    return 0;
}

static struct fb_ops maxinefb_ops = {
    .owner      = THIS_MODULE,
    .fb_setcolreg   = maxinefb_setcolreg,
    .fb_fillrect    = cfb_fillrect,
    .fb_copyarea    = cfb_copyarea,
    .fb_imageblit   = cfb_imageblit,
};

int __init maxinefb_init(void)
{
    unsigned long fboff;
    unsigned long fb_start;
    int i;

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

    /* Validate we're on the proper machine type */
    if (mips_machtype != MACH_DS5000_XX) {
        return -EINVAL;
    }

    printk(KERN_INFO "Maxinefb: Personal DECstation detected\n");
    printk(KERN_INFO "Maxinefb: initializing onboard framebuffer\n");

    /* Framebuffer display memory base address */
    fb_start = DS5000_xx_ONBOARD_FBMEM_START;

    /* Clear screen */
    for (fboff = fb_start; fboff < fb_start + 0x1ffff; fboff++)
        *(volatile unsigned char *)fboff = 0x0;

    maxinefb_fix.smem_start = fb_start;
    
    /* erase hardware cursor */
    for (i = 0; i < 512; i++) {
        maxinefb_ims332_write_register(IMS332_REG_CURSOR_RAM + i,
                           0);
        /*
           if (i&0x8 == 0)
           maxinefb_ims332_write_register (IMS332_REG_CURSOR_RAM + i, 0x0f);
           else
           maxinefb_ims332_write_register (IMS332_REG_CURSOR_RAM + i, 0xf0);
         */
    }

    fb_info.fbops = &maxinefb_ops;
    fb_info.screen_base = (char *)maxinefb_fix.smem_start;
    fb_info.var = maxinefb_defined;
    fb_info.fix = maxinefb_fix;
    fb_info.flags = FBINFO_DEFAULT;

    fb_alloc_cmap(&fb_info.cmap, 256, 0);

    if (register_framebuffer(&fb_info) < 0)
        return 1;
    return 0;
}

static void __exit maxinefb_exit(void)
{
    unregister_framebuffer(&fb_info);
}

#ifdef MODULE
MODULE_LICENSE("GPL");
#endif
module_init(maxinefb_init);
module_exit(maxinefb_exit);