igafb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

/*
 *  linux/drivers/video/igafb.c -- Frame buffer device for IGA 1682
 *
 *      Copyright (C) 1998  Vladimir Roganov and Gleb Raiko
 *
 *  This driver is partly based on the Frame buffer device for ATI Mach64
 *  and partially on VESA-related code.
 *
 *      Copyright (C) 1997-1998  Geert Uytterhoeven
 *      Copyright (C) 1998  Bernd Harries
 *      Copyright (C) 1998  Eddie C. Dost  ([e-mail])
 *
 *  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.
 */

/******************************************************************************

  TODO:
       Despite of IGA Card has advanced graphic acceleration, 
       initial version is almost dummy and does not support it.
       Support for video modes and acceleration must be added
       together with accelerated X-Windows driver implementation.

       Most important thing at this moment is that we have working
       JavaEngine1  console & X  with new console interface.

******************************************************************************/

#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/console.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/nvram.h>
#include <linux/kd.h>
#include <linux/vt_kern.h>

#include <asm/io.h>

#ifdef __sparc__
#include <asm/pbm.h>
#include <asm/pcic.h>
#endif

#include <video/fbcon.h>
#include <video/fbcon-cfb8.h>
#include <video/fbcon-cfb16.h>
#include <video/fbcon-cfb24.h>
#include <video/fbcon-cfb32.h>

#include "iga.h"

static char igafb_name[16] = "IGA 1682";
static char fontname[40] __initdata = { 0 };

struct pci_mmap_map {
    unsigned long voff;
    unsigned long poff;
    unsigned long size;
    unsigned long prot_flag;
    unsigned long prot_mask;
};

struct fb_info_iga {
    struct fb_info fb_info;
    unsigned long frame_buffer_phys;
    char *frame_buffer;
    unsigned long io_base_phys;
    unsigned long io_base;
    u32 total_vram;
    struct pci_mmap_map *mmap_map;
    struct { u_short blue, green, red, pad; } palette[256];
    int video_cmap_len;
    int currcon;
    struct display disp;
    struct display_switch dispsw; 
    union {
#ifdef FBCON_HAS_CFB16
	    u16 cfb16[16];  
#endif
#ifdef FBCON_HAS_CFB24
	    u32 cfb24[16];
#endif
#ifdef FBCON_HAS_CFB32
	    u32 cfb32[16];
#endif
    } fbcon_cmap;
#ifdef __sparc__
    u8 open;
    u8 mmaped;
    int vtconsole;
    int consolecnt;
#endif
};

struct fb_var_screeninfo default_var = {
    /* 640x480, 60 Hz, Non-Interlaced (25.175 MHz dotclock) */
    640, 480, 640, 480, 0, 0, 8, 0,
    {0, 8, 0}, {0, 8, 0}, {0, 8, 0}, {0, 0, 0},
    0, 0, -1, -1, 0, 39722, 48, 16, 33, 10, 96, 2,
    0, FB_VMODE_NONINTERLACED
};

#ifdef __sparc__
struct fb_var_screeninfo default_var_1024x768 __initdata = {
    /* 1024x768, 75 Hz, Non-Interlaced (78.75 MHz dotclock) */
    1024, 768, 1024, 768, 0, 0, 8, 0,
    {0, 8, 0}, {0, 8, 0}, {0, 8, 0}, {0, 0, 0},
    0, 0, -1, -1, 0, 12699, 176, 16, 28, 1, 96, 3,
    FB_SYNC_HOR_HIGH_ACT|FB_SYNC_VERT_HIGH_ACT, FB_VMODE_NONINTERLACED
};

struct fb_var_screeninfo default_var_1152x900 __initdata = {
    /* 1152x900, 76 Hz, Non-Interlaced (110.0 MHz dotclock) */
    1152, 900, 1152, 900, 0, 0, 8, 0,
    {0, 8, 0}, {0, 8, 0}, {0, 8, 0}, {0, 0, 0},
    0, 0, -1, -1, 0, 9091, 234, 24, 34, 3, 100, 3,
    FB_SYNC_HOR_HIGH_ACT|FB_SYNC_VERT_HIGH_ACT, FB_VMODE_NONINTERLACED
};

struct fb_var_screeninfo default_var_1280x1024 __initdata = {
    /* 1280x1024, 75 Hz, Non-Interlaced (135.00 MHz dotclock) */
    1280, 1024, 1280, 1024, 0, 0, 8, 0,
    {0, 8, 0}, {0, 8, 0}, {0, 8, 0}, {0, 0, 0},
    0, 0, -1, -1, 0, 7408, 248, 16, 38, 1, 144, 3,
    FB_SYNC_HOR_HIGH_ACT|FB_SYNC_VERT_HIGH_ACT, FB_VMODE_NONINTERLACED
};

/*
 *   Memory-mapped I/O functions for Sparc PCI
 *
 * On sparc we happen to access I/O with memory mapped functions too.
 */ 
#define pci_inb(info, reg)        readb(info->io_base+(reg))
#define pci_outb(info, val, reg)  writeb(val, info->io_base+(reg))

static inline unsigned int iga_inb(struct fb_info_iga *info,
				   unsigned int reg, unsigned int idx )
{
        pci_outb(info, idx, reg);
        return pci_inb(info, reg + 1);
}

static inline void iga_outb(struct fb_info_iga *info, unsigned char val,
			    unsigned int reg, unsigned int idx )
{
        pci_outb(info, idx, reg);
        pci_outb(info, val, reg+1);
}

#endif /* __sparc__ */

/*
 *  Very important functionality for the JavaEngine1 computer:
 *  make screen border black (usign special IGA registers) 
 */
static void iga_blank_border(struct fb_info_iga *info)
{
        int i;

#if 0
	/*
	 * PROM does this for us, so keep this code as a reminder
	 * about required read from 0x3DA and writing of 0x20 in the end.
	 */
	(void) pci_inb(info, 0x3DA);		/* required for every access */
	pci_outb(info, IGA_IDX_VGA_OVERSCAN, IGA_ATTR_CTL);
	(void) pci_inb(info, IGA_ATTR_CTL+1);
	pci_outb(info, 0x38, IGA_ATTR_CTL);
	pci_outb(info, 0x20, IGA_ATTR_CTL);	/* re-enable visual */
#endif
	/*
	 * This does not work as it was designed because the overscan
	 * color is looked up in the palette. Therefore, under X11
	 * overscan changes color.
	 */
	for (i=0; i < 3; i++)
		iga_outb(info, 0, IGA_EXT_CNTRL, IGA_IDX_OVERSCAN_COLOR + i);
}


/*
 *  Frame buffer device API
 */

static int igafb_update_var(int con, struct fb_info *info)
{
        return 0;
}

static int igafb_get_fix(struct fb_fix_screeninfo *fix, int con,
                         struct fb_info *info)
{
        struct fb_info_iga *fb = (struct fb_info_iga*)info;

        memset(fix, 0, sizeof(struct fb_fix_screeninfo));
        strcpy(fix->id, igafb_name);

        fix->smem_start = (unsigned long) fb->frame_buffer;
        fix->smem_len = fb->total_vram;
        fix->xpanstep = 0;
        fix->ypanstep = 0;
        fix->ywrapstep = 0;

	fix->type = FB_TYPE_PACKED_PIXELS;
	fix->type_aux = 0;
	fix->line_length = default_var.xres * (default_var.bits_per_pixel/8);
	fix->visual = default_var.bits_per_pixel <= 8 ? FB_VISUAL_PSEUDOCOLOR
		                                      : FB_VISUAL_DIRECTCOLOR;
        return 0;
}

static int igafb_get_var(struct fb_var_screeninfo *var, int con,
                         struct fb_info *info)
{
        if(con == -1)
                memcpy(var, &default_var, sizeof(struct fb_var_screeninfo));
        else
                *var = fb_display[con].var;
        return 0;
}

static int igafb_set_var(struct fb_var_screeninfo *var, int con,
                         struct fb_info *info)
{
        memcpy(var, &default_var, sizeof(struct fb_var_screeninfo));
        return 0;
}

#ifdef __sparc__
static int igafb_mmap(struct fb_info *info, struct file *file,
		      struct vm_area_struct *vma)
{
	struct fb_info_iga *fb = (struct fb_info_iga *)info;
	unsigned int size, page, map_size = 0;
	unsigned long map_offset = 0;
	int i;

	if (!fb->mmap_map)
		return -ENXIO;

	size = vma->vm_end - vma->vm_start;

	/* To stop the swapper from even considering these pages. */
	vma->vm_flags |= (VM_SHM | VM_LOCKED);

	/* Each page, see which map applies */
	for (page = 0; page < size; ) {
		map_size = 0;
		for (i = 0; fb->mmap_map[i].size; i++) {
			unsigned long start = fb->mmap_map[i].voff;
			unsigned long end = start + fb->mmap_map[i].size;
			unsigned long offset = (vma->vm_pgoff << PAGE_SHIFT) + page;

			if (start > offset)
				continue;
			if (offset >= end)
				continue;

			map_size = fb->mmap_map[i].size - (offset - start);
			map_offset = fb->mmap_map[i].poff + (offset - start);
			break;
		}
		if (!map_size) {
			page += PAGE_SIZE;
			continue;
		}
		if (page + map_size > size)
			map_size = size - page;

		pgprot_val(vma->vm_page_prot) &= ~(fb->mmap_map[i].prot_mask);
		pgprot_val(vma->vm_page_prot) |= fb->mmap_map[i].prot_flag;

		if (remap_page_range(vma->vm_start + page, map_offset,
				     map_size, vma->vm_page_prot))
			return -EAGAIN;

		page += map_size;
	}

	if (!map_size)
		return -EINVAL;

	if (!fb->mmaped) {
		int lastconsole = 0;

		if (info->display_fg)
			lastconsole = info->display_fg->vc_num;
		fb->mmaped = 1;
		if (fb->consolecnt && fb_display[lastconsole].fb_info ==info) {
			fb->vtconsole = lastconsole;
			vt_cons[lastconsole]->vc_mode = KD_GRAPHICS;
		}
	}
	return 0;
}
#endif /* __sparc__ */


static int iga_getcolreg(unsigned regno, unsigned *red, unsigned *green,
                          unsigned *blue, unsigned *transp,
                          struct fb_info *fb_info)
{
        /*
         *  Read a single color register and split it into colors/transparent.
         *  Return != 0 for invalid regno.
         */
	struct fb_info_iga *info = (struct fb_info_iga*) fb_info;

        if (regno >= info->video_cmap_len)
                return 1;

	*red    = info->palette[regno].red;
	*green  = info->palette[regno].green;
	*blue   = info->palette[regno].blue;
	*transp = 0;
	return 0;
}

static int iga_setcolreg(unsigned regno, unsigned red, unsigned green,
                          unsigned blue, unsigned transp,
                          struct fb_info *fb_info)
{
        /*
         *  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.
         */
        
	struct fb_info_iga *info = (struct fb_info_iga*) fb_info;

        if (regno >= info->video_cmap_len)
                return 1;

        info->palette[regno].red   = red;
        info->palette[regno].green = green;
        info->palette[regno].blue  = blue;

	pci_outb(info, regno, DAC_W_INDEX);
	pci_outb(info, red,   DAC_DATA);
	pci_outb(info, green, DAC_DATA);
	pci_outb(info, blue,  DAC_DATA);

	if (regno < 16) {
		switch (default_var.bits_per_pixel) {
#ifdef FBCON_HAS_CFB16
		case 16:
			info->fbcon_cmap.cfb16[regno] = 
				(regno << 10) | (regno << 5) | regno;
			break;
#endif
#ifdef FBCON_HAS_CFB24
		case 24:
			info->fbcon_cmap.cfb24[regno] = 
				(regno << 16) | (regno << 8) | regno;
		break;
#endif
#ifdef FBCON_HAS_CFB32
		case 32:
			{ int i;
			i = (regno << 8) | regno;
			info->fbcon_cmap.cfb32[regno] = (i << 16) | i;
			}
			break;
#endif
		}
	}
	return 0;
}

static void do_install_cmap(int con, struct fb_info *fb_info)
{
	struct fb_info_iga *info = (struct fb_info_iga*) fb_info;

        if (con != info->currcon)
                return;
        if (fb_display[con].cmap.len)
                fb_set_cmap(&fb_display[con].cmap, 1,
                            iga_setcolreg, &info->fb_info);
        else
                fb_set_cmap(fb_default_cmap(info->video_cmap_len), 1, 
			    iga_setcolreg, &info->fb_info);
}