offb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

/*
 *  linux/drivers/video/offb.c -- Open Firmware based frame buffer device
 *
 *	Copyright (C) 1997 Geert Uytterhoeven
 *
 *  This driver is partly based on the PowerMac console driver:
 *
 *	Copyright (C) 1996 Paul Mackerras
 *
 *  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/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/tty.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/selection.h>
#include <linux/init.h>
#include <linux/ioport.h>
#ifdef CONFIG_FB_COMPAT_XPMAC
#include <asm/vc_ioctl.h>
#endif
#include <asm/io.h>
#include <asm/prom.h>
#ifdef CONFIG_BOOTX_TEXT
#include <asm/bootx.h>
#endif

#include <video/fbcon.h>
#include <video/fbcon-cfb8.h>
#include <video/fbcon-cfb16.h>
#include <video/fbcon-cfb32.h>
#include <video/macmodes.h>


static int currcon = 0;

/* Supported palette hacks */
enum {
	cmap_unknown,
	cmap_m64,	/* ATI Mach64 */
	cmap_r128,	/* ATI Rage128 */
	cmap_M3A,	/* ATI Rage Mobility M3 Head A */
	cmap_M3B,	/* ATI Rage Mobility M3 Head B */
	cmap_radeon,	/* ATI Radeon */
	cmap_gxt2000	/* IBM GXT2000 */
};

struct fb_info_offb {
    struct fb_info info;
    struct fb_fix_screeninfo fix;
    struct fb_var_screeninfo var;
    struct display disp;
    struct { u_char red, green, blue, pad; } palette[256];
    volatile unsigned char *cmap_adr;
    volatile unsigned char *cmap_data;
    int cmap_type;
    int blanked;
    union {
#ifdef FBCON_HAS_CFB16
	u16 cfb16[16];
#endif
#ifdef FBCON_HAS_CFB32
	u32 cfb32[16];
#endif
    } fbcon_cmap;
};

#ifdef __powerpc__
#define mach_eieio()	eieio()
#else
#define mach_eieio()	do {} while (0)
#endif


    /*
     *  Interface used by the world
     */

int offb_init(void);

static int offb_get_fix(struct fb_fix_screeninfo *fix, int con,
			struct fb_info *info);
static int offb_get_var(struct fb_var_screeninfo *var, int con,
			struct fb_info *info);
static int offb_set_var(struct fb_var_screeninfo *var, int con,
			struct fb_info *info);
static int offb_get_cmap(struct fb_cmap *cmap, int kspc, int con,
			struct fb_info *info);
static int offb_set_cmap(struct fb_cmap *cmap, int kspc, int con,
			struct fb_info *info);
#ifdef CONFIG_BOOTX_TEXT
extern boot_infos_t *boot_infos;
#endif

static void offb_init_nodriver(struct device_node *);
static void offb_init_fb(const char *name, const char *full_name, int width,
		      int height, int depth, int pitch, unsigned long address,
		      struct device_node *dp);

    /*
     *  Interface to the low level console driver
     */

static int offbcon_switch(int con, struct fb_info *info);
static int offbcon_updatevar(int con, struct fb_info *info);
static void offbcon_blank(int blank, struct fb_info *info);


    /*
     *  Internal routines
     */

static int offb_getcolreg(u_int regno, u_int *red, u_int *green, u_int *blue,
			 u_int *transp, struct fb_info *info);
static int offb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
			 u_int transp, struct fb_info *info);
static void do_install_cmap(int con, struct fb_info *info);


static struct fb_ops offb_ops = {
	owner:		THIS_MODULE,
	fb_get_fix:	offb_get_fix,
	fb_get_var:	offb_get_var,
	fb_set_var:	offb_set_var,
	fb_get_cmap:	offb_get_cmap,
	fb_set_cmap:	offb_set_cmap,
};

    /*
     *  Get the Fixed Part of the Display
     */

static int offb_get_fix(struct fb_fix_screeninfo *fix, int con,
			struct fb_info *info)
{
    struct fb_info_offb *info2 = (struct fb_info_offb *)info;

    memcpy(fix, &info2->fix, sizeof(struct fb_fix_screeninfo));
    return 0;
}


    /*
     *  Get the User Defined Part of the Display
     */

static int offb_get_var(struct fb_var_screeninfo *var, int con,
			struct fb_info *info)
{
    struct fb_info_offb *info2 = (struct fb_info_offb *)info;

    memcpy(var, &info2->var, sizeof(struct fb_var_screeninfo));
    return 0;
}


    /*
     *  Set the User Defined Part of the Display
     */

static int offb_set_var(struct fb_var_screeninfo *var, int con,
			struct fb_info *info)
{
    struct display *display;
    unsigned int oldbpp = 0;
    int err;
    int activate = var->activate;
    struct fb_info_offb *info2 = (struct fb_info_offb *)info;

    if (con >= 0)
	display = &fb_display[con];
    else
	display = &info2->disp;	/* used during initialization */

    if (var->xres > info2->var.xres || var->yres > info2->var.yres ||
	var->xres_virtual > info2->var.xres_virtual ||
	var->yres_virtual > info2->var.yres_virtual ||
	var->bits_per_pixel > info2->var.bits_per_pixel ||
	var->nonstd ||
	(var->vmode & FB_VMODE_MASK) != FB_VMODE_NONINTERLACED)
	return -EINVAL;
    memcpy(var, &info2->var, sizeof(struct fb_var_screeninfo));

    if ((activate & FB_ACTIVATE_MASK) == FB_ACTIVATE_NOW) {
	oldbpp = display->var.bits_per_pixel;
	display->var = *var;
    }
    if ((oldbpp != var->bits_per_pixel) || (display->cmap.len == 0)) {
	if ((err = fb_alloc_cmap(&display->cmap, 0, 0)))
	    return err;
	do_install_cmap(con, info);
    }
    return 0;
}


    /*
     *  Get the Colormap
     */

static int offb_get_cmap(struct fb_cmap *cmap, int kspc, int con,
			 struct fb_info *info)
{
    struct fb_info_offb *info2 = (struct fb_info_offb *)info;

    if (con == currcon && !info2->blanked) /* current console? */
	return fb_get_cmap(cmap, kspc, offb_getcolreg, info);
    if (fb_display[con].cmap.len) /* non default colormap? */
	fb_copy_cmap(&fb_display[con].cmap, cmap, kspc ? 0 : 2);
    else
    {
	int size = fb_display[con].var.bits_per_pixel == 16 ? 32 : 256;
	fb_copy_cmap(fb_default_cmap(size), cmap, kspc ? 0 : 2);
    }
    return 0;
}

    /*
     *  Set the Colormap
     */

static int offb_set_cmap(struct fb_cmap *cmap, int kspc, int con,
			 struct fb_info *info)
{
    struct fb_info_offb *info2 = (struct fb_info_offb *)info;
    int err;

    if (!info2->cmap_adr)
	return -ENOSYS;

    if (!fb_display[con].cmap.len) {	/* no colormap allocated? */
	int size = fb_display[con].var.bits_per_pixel == 16 ? 32 : 256;
	if ((err = fb_alloc_cmap(&fb_display[con].cmap, size, 0)))
	    return err;
    }
    if (con == currcon && !info2->blanked)		/* current console? */
	return fb_set_cmap(cmap, kspc, offb_setcolreg, info);
    else
	fb_copy_cmap(cmap, &fb_display[con].cmap, kspc ? 0 : 1);
    return 0;
}


    /*
     *  Initialisation
     */

int __init offb_init(void)
{
    struct device_node *dp;
    unsigned int dpy;
#ifdef CONFIG_BOOTX_TEXT
    struct device_node *displays = find_type_devices("display");
    struct device_node *macos_display = NULL;

    /* If we're booted from BootX... */
    if (prom_num_displays == 0 && boot_infos != 0) {
	unsigned long addr = (unsigned long) boot_infos->dispDeviceBase;
	/* find the device node corresponding to the macos display */
	for (dp = displays; dp != NULL; dp = dp->next) {
	    int i;
	    /*
	     * Grrr...  It looks like the MacOS ATI driver
	     * munges the assigned-addresses property (but
	     * the AAPL,address value is OK).
	     */
	    if (strncmp(dp->name, "ATY,", 4) == 0 && dp->n_addrs == 1) {
		unsigned int *ap = (unsigned int *)
		    get_property(dp, "AAPL,address", NULL);
		if (ap != NULL) {
		    dp->addrs[0].address = *ap;
		    dp->addrs[0].size = 0x01000000;
		}
	    }

	    /*
	     * The LTPro on the Lombard powerbook has no addresses
	     * on the display nodes, they are on their parent.
	     */
	    if (dp->n_addrs == 0 && device_is_compatible(dp, "ATY,264LTPro")) {
		int na;
		unsigned int *ap = (unsigned int *)
		    get_property(dp, "AAPL,address", &na);
		if (ap != 0)
		    for (na /= sizeof(unsigned int); na > 0; --na, ++ap)
			if (*ap <= addr && addr < *ap + 0x1000000)
			    goto foundit;
	    }

	    /*
	     * See if the display address is in one of the address
	     * ranges for this display.
	     */
	    for (i = 0; i < dp->n_addrs; ++i) {
		if (dp->addrs[i].address <= addr
		    && addr < dp->addrs[i].address + dp->addrs[i].size)
		    break;
	    }
	    if (i < dp->n_addrs) {
	    foundit:
		printk(KERN_INFO "MacOS display is %s\n", dp->full_name);
		macos_display = dp;
		break;
	    }
	}

	/* initialize it */
	offb_init_fb(macos_display? macos_display->name: "MacOS display",
		     macos_display? macos_display->full_name: "MacOS display",
		     boot_infos->dispDeviceRect[2],
		     boot_infos->dispDeviceRect[3],
		     boot_infos->dispDeviceDepth,
		     boot_infos->dispDeviceRowBytes, addr, NULL);
    }
#endif

    for (dpy = 0; dpy < prom_num_displays; dpy++) {
	if ((dp = find_path_device(prom_display_paths[dpy])))
	    offb_init_nodriver(dp);
    }
    return 0;
}


static void __init offb_init_nodriver(struct device_node *dp)
{
    int *pp, i;
    unsigned int len;
    int width = 640, height = 480, depth = 8, pitch;
    unsigned *up, address;

    if ((pp = (int *)get_property(dp, "depth", &len)) != NULL
	&& len == sizeof(int))
	depth = *pp;
    if ((pp = (int *)get_property(dp, "width", &len)) != NULL
	&& len == sizeof(int))
	width = *pp;
    if ((pp = (int *)get_property(dp, "height", &len)) != NULL
	&& len == sizeof(int))
	height = *pp;
    if ((pp = (int *)get_property(dp, "linebytes", &len)) != NULL
	&& len == sizeof(int)) {
	pitch = *pp;
	if (pitch == 1)
	    pitch = 0x1000;
    } else
	pitch = width;
    if ((up = (unsigned *)get_property(dp, "address", &len)) != NULL
	&& len == sizeof(unsigned))
	address = (u_long)*up;
    else {
	for (i = 0; i < dp->n_addrs; ++i)
	    if (dp->addrs[i].size >= pitch*height*depth/8)
		break;
	if (i >= dp->n_addrs) {
	    printk(KERN_ERR "no framebuffer address found for %s\n", dp->full_name);
	    return;
	}

	address = (u_long)dp->addrs[i].address;

	/* kludge for valkyrie */
	if (strcmp(dp->name, "valkyrie") == 0) 
	    address += 0x1000;
    }
    offb_init_fb(dp->name, dp->full_name, width, height, depth,
		 pitch, address, dp);
    
}

static void __init offb_init_fb(const char *name, const char *full_name,
				    int width, int height, int depth,
				    int pitch, unsigned long address,
				    struct device_node *dp)
{
    int i;
    struct fb_fix_screeninfo *fix;
    struct fb_var_screeninfo *var;
    struct display *disp;
    struct fb_info_offb *info;
    unsigned long res_start = address;
    unsigned long res_size = pitch*height*depth/8;

    if (!request_mem_region(res_start, res_size, "offb"))
	return;

    printk(KERN_INFO "Using unsupported %dx%d %s at %lx, depth=%d, pitch=%d\n",
	   width, height, name, address, depth, pitch);
    if (depth != 8 && depth != 16 && depth != 32) {
	printk(KERN_ERR "%s: can't use depth = %d\n", full_name, depth);
	release_mem_region(res_start, res_size);
	return;
    }

    info = kmalloc(sizeof(struct fb_info_offb), GFP_ATOMIC);
    if (info == 0) {
	release_mem_region(res_start, res_size);
	return;
    }
    memset(info, 0, sizeof(*info));

    fix = &info->fix;
    var = &info->var;
    disp = &info->disp;

    strcpy(fix->id, "OFfb ");
    strncat(fix->id, name, sizeof(fix->id));
    fix->id[sizeof(fix->id)-1] = '\0';