pvr2fb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

/* drivers/video/pvr2fb.c
 *
 * Frame buffer and fbcon support for the NEC PowerVR2 found within the Sega
 * Dreamcast.
 *
 * Copyright (c) 2001 M. R. Brown <[e-mail]>
 * Copyright (c) 2001 Paul Mundt  <[e-mail]>
 *
 * This file is part of the LinuxDC project (linuxdc.sourceforge.net).
 *
 */

/*
 * This driver is mostly based on the excellent amifb and vfb sources.  It uses
 * an odd scheme for converting hardware values to/from framebuffer values, here are
 * some hacked-up formulas:
 *
 *  The Dreamcast has screen offsets from each side of it's four borders and the start
 *  offsets of the display window.  I used these values to calculate 'pseudo' values
 *  (think of them as placeholders) for the fb video mode, so that when it came time
 *  to convert these values back into their hardware values, I could just add mode-
 *  specific offsets to get the correct mode settings:
 *
 *      left_margin = diwstart_h - borderstart_h;
 *      right_margin = borderstop_h - (diwstart_h + xres);
 *      upper_margin = diwstart_v - borderstart_v;
 *      lower_margin = borderstop_v - (diwstart_h + yres);
 *
 *      hsync_len = borderstart_h + (hsync_total - borderstop_h);
 *      vsync_len = borderstart_v + (vsync_total - borderstop_v);
 *
 *  Then, when it's time to convert back to hardware settings, the only constants
 *  are the borderstart_* offsets, all other values are derived from the fb video
 *  mode:
 *  
 *      // PAL
 *      borderstart_h = 116;
 *      borderstart_v = 44;
 *      ...
 *      borderstop_h = borderstart_h + hsync_total - hsync_len;
 *      ...
 *      diwstart_v = borderstart_v - upper_margin;
 *
 *  However, in the current implementation, the borderstart values haven't had
 *  the benefit of being fully researched, so some modes may be broken.
 */

#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/delay.h>
#include <linux/config.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/console.h>

#ifdef CONFIG_SH_DREAMCAST
#include <asm/io.h>
#include <asm/machvec.h>
#include <asm/dc_sysasic.h>
#endif

#ifdef CONFIG_MTRR
  #include <asm/mtrr.h>
#endif

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

#ifdef CONFIG_FB_PVR2_DEBUG
#  define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt, __FUNCTION__ , ## args)
#else
#  define DPRINTK(fmt, args...)
#endif

/* 2D video registers */
#define DISP_BASE 0xa05f8000

#define DISP_BRDRCOLR (DISP_BASE + 0x40)
#define DISP_DIWMODE (DISP_BASE + 0x44)
#define DISP_DIWADDRL (DISP_BASE + 0x50)
#define DISP_DIWADDRS (DISP_BASE + 0x54)
#define DISP_DIWSIZE (DISP_BASE + 0x5c)
#define DISP_SYNCCONF (DISP_BASE + 0xd0)
#define DISP_BRDRHORZ (DISP_BASE + 0xd4)
#define DISP_SYNCSIZE (DISP_BASE + 0xd8)
#define DISP_BRDRVERT (DISP_BASE + 0xdc)
#define DISP_DIWCONF (DISP_BASE + 0xe8)
#define DISP_DIWHSTRT (DISP_BASE + 0xec)
#define DISP_DIWVSTRT (DISP_BASE + 0xf0)

/* Pixel clocks, one for TV output, doubled for VGA output */
#define TV_CLK 74239
#define VGA_CLK 37119

/* This is for 60Hz - the VTOTAL is doubled for interlaced modes */
#define PAL_HTOTAL 863
#define PAL_VTOTAL 312
#define NTSC_HTOTAL 857
#define NTSC_VTOTAL 262

enum { CT_VGA, CT_NONE, CT_RGB, CT_COMPOSITE };

enum { VO_PAL, VO_NTSC, VO_VGA };

struct pvr2_params { u_short val; char *name; };
static struct pvr2_params cables[] __initdata = {
	{ CT_VGA, "VGA" }, { CT_RGB, "RGB" }, { CT_COMPOSITE, "COMPOSITE" },
};

static struct pvr2_params outputs[] __initdata = {
	{ VO_PAL, "PAL" }, { VO_NTSC, "NTSC" }, { VO_VGA, "VGA" },
};

/*
 * This describes the current video mode
 */

static struct pvr2fb_par {

	int xres;
	int yres;
	int vxres;
	int vyres;
	int xoffset;
	int yoffset;
	u_short bpp;

	u_long pixclock;
	u_short hsync_total;	/* Clocks/line */
	u_short vsync_total;	/* Lines/field */
	u_short borderstart_h;
	u_short borderstop_h;
	u_short borderstart_v;
	u_short borderstop_v;
	u_short diwstart_h;	/* Horizontal offset of the display field */
	u_short diwstart_v;	/* Vertical offset of the display field, for
				   interlaced modes, this is the long field */
	u_long disp_start;	/* Address of image within VRAM */

	u_long next_line;	/* Modulo for next line */

	u_char is_interlaced;	/* Is the display interlaced? */
	u_char is_doublescan;	/* Are scanlines output twice? (doublescan) */
	u_char is_lowres;	/* Is horizontal pixel-doubling enabled? */

	u_long bordercolor;	/* RGB888 format border color */

	u_long vmode;
	
} currentpar;

static int currcon = 0;
static int currbpp;
static struct display disp;
static struct fb_info fb_info;
static int pvr2fb_inverse = 0;

static struct { u_short red, green, blue, alpha; } palette[256];
static 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;

static char pvr2fb_name[16] = "NEC PowerVR2";

#define VIDEOMEMSIZE (8*1024*1024)
static u_long videomemory = 0xa5000000, videomemorysize = VIDEOMEMSIZE;
static int cable_type = -1;
static int video_output = -1;

#ifdef CONFIG_MTRR
static int enable_mtrr = 1;
static int mtrr_handle;
#endif

/*
 * We do all updating, blanking, etc. during the vertical retrace period
 */

static u_short do_vmode_full = 0;	/* Change the video mode */
static u_short do_vmode_pan = 0;	/* Update the video mode */
static short do_blank = 0;		/* (Un)Blank the screen */

static u_short is_blanked = 0;		/* Is the screen blanked? */

/* Interface used by the world */

int pvr2fb_setup(char*);

static int pvr2fb_get_fix(struct fb_fix_screeninfo *fix, int con,
                            struct fb_info *info);
static int pvr2fb_get_var(struct fb_var_screeninfo *var, int con,
                            struct fb_info *info);
static int pvr2fb_set_var(struct fb_var_screeninfo *var, int con,
                            struct fb_info *info);
static int pvr2fb_pan_display(struct fb_var_screeninfo *var, int con,
                                struct fb_info *info);
static int pvr2fb_get_cmap(struct fb_cmap *cmap, int kspc, int con,
                             struct fb_info *info);
static int pvr2fb_set_cmap(struct fb_cmap *cmap, int kspc, int con,
                             struct fb_info *info);

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

static int pvr2fbcon_switch(int con, struct fb_info *info);
static int pvr2fbcon_updatevar(int con, struct fb_info *info);
static void pvr2fbcon_blank(int blank, struct fb_info *info);

	/*
	 * Internal/hardware-specific routines
	 */

static void do_install_cmap(int con, struct fb_info *info);
static u_long get_line_length(int xres_virtual, int bpp);
static void set_color_bitfields(struct fb_var_screeninfo *var);
static int pvr2_getcolreg(u_int regno, u_int *red, u_int *green, u_int *blue,
                            u_int *transp, struct fb_info *info);
static int pvr2_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                            u_int transp, struct fb_info *info);

static int pvr2_encode_fix(struct fb_fix_screeninfo *fix,
                             struct pvr2fb_par *par);
static int pvr2_decode_var(struct fb_var_screeninfo *var,
                          struct pvr2fb_par *par);
static int pvr2_encode_var(struct fb_var_screeninfo *var,
                          struct pvr2fb_par *par);
static void pvr2_get_par(struct pvr2fb_par *par);
static void pvr2_set_var(struct fb_var_screeninfo *var);
static void pvr2_pan_var(struct fb_var_screeninfo *var);
static int pvr2_update_par(void);
static void pvr2_update_display(void);
static void pvr2_init_display(void);
static void pvr2_do_blank(void);
static void pvr2fb_interrupt(int irq, void *dev_id, struct pt_regs *fp);
static int pvr2_init_cable(void);
static int pvr2_get_param(const struct pvr2_params *p, const char *s,
                            int val, int size);

static struct fb_ops pvr2fb_ops = {
	owner:		THIS_MODULE,
	fb_get_fix:	pvr2fb_get_fix,
	fb_get_var:	pvr2fb_get_var,
	fb_set_var:	pvr2fb_set_var,
	fb_get_cmap:	pvr2fb_get_cmap,
	fb_set_cmap:	pvr2fb_set_cmap,
	fb_pan_display: pvr2fb_pan_display,
};

static struct fb_videomode pvr2_modedb[] __initdata = {

    /*
     * Broadcast video modes (PAL and NTSC).  I'm unfamiliar with
     * PAL-M and PAL-N, but from what I've read both modes parallel PAL and
     * NTSC, so it shouldn't be a problem (I hope).
     */

    {
	/* 640x480 @ 60Hz interlaced (NTSC) */
	"ntsc_640x480i", 60, 640, 480, TV_CLK, 38, 33, 0, 18, 146, 26,
	FB_SYNC_BROADCAST, FB_VMODE_INTERLACED | FB_VMODE_YWRAP
    },

    {
	/* 640x240 @ 60Hz (NTSC) */
	/* XXX: Broken! Don't use... */
	"ntsc_640x240", 60, 640, 240, TV_CLK, 38, 33, 0, 0, 146, 22,
	FB_SYNC_BROADCAST, FB_VMODE_YWRAP
    },

    {
	/* 640x480 @ 60hz (VGA) */
	"vga_640x480", 60, 640, 480, VGA_CLK, 38, 33, 0, 18, 146, 26,
	0, FB_VMODE_YWRAP
    },

};

#define NUM_TOTAL_MODES  ARRAY_SIZE(pvr2_modedb)

#define DEFMODE_NTSC	0
#define DEFMODE_PAL	0
#define DEFMODE_VGA	2

static int defmode = DEFMODE_NTSC;
static char *mode_option __initdata = NULL;

/* Get the fixed part of the display */

static int pvr2fb_get_fix(struct fb_fix_screeninfo *fix, int con,
                            struct fb_info *info)
{
	struct pvr2fb_par par;

	if (con == -1)
		pvr2_get_par(&par);
	else {
		int err;

		if ((err = pvr2_decode_var(&fb_display[con].var, &par)))
			return err;
	}
	return pvr2_encode_fix(fix, &par);
}

/* Get the user-defined part of the display */

static int pvr2fb_get_var(struct fb_var_screeninfo *var, int con,
                            struct fb_info *info)
{
	int err = 0;

	if (con == -1) {
		struct pvr2fb_par par;

		pvr2_get_par(&par);
		err = pvr2_encode_var(var, &par);
	} else
		*var = fb_display[con].var;
	
	return err;
}

/* Set the user-defined part of the display */

static int pvr2fb_set_var(struct fb_var_screeninfo *var, int con,
                            struct fb_info *info)
{
	int err, activate = var->activate;
	int oldxres, oldyres, oldvxres, oldvyres, oldbpp;
	struct pvr2fb_par par;

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

	/*
	 * FB_VMODE_CONUPDATE and FB_VMODE_SMOOTH_XPAN are equal!
	 * as FB_VMODE_SMOOTH_XPAN is only used internally
	 */

	if (var->vmode & FB_VMODE_CONUPDATE) {
		var->vmode |= FB_VMODE_YWRAP;
		var->xoffset = display->var.xoffset;
		var->yoffset = display->var.yoffset;
	}
	if ((err = pvr2_decode_var(var, &par)))
		return err;
	pvr2_encode_var(var, &par);

	/* Do memory check and bitfield set here?? */

	if ((activate & FB_ACTIVATE_MASK) == FB_ACTIVATE_NOW) {
		oldxres = display->var.xres;
		oldyres = display->var.yres;
		oldvxres = display->var.xres_virtual;
		oldvyres = display->var.yres_virtual;
		oldbpp = display->var.bits_per_pixel;
		display->var = *var;
		if (oldxres != var->xres || oldyres != var->yres ||
		    oldvxres != var->xres_virtual || oldvyres != var->yres_virtual ||
		    oldbpp != var->bits_per_pixel) {
			struct fb_fix_screeninfo fix;

			pvr2_encode_fix(&fix, &par);
			display->screen_base = (char *)fix.smem_start;
			display->scrollmode = SCROLL_YREDRAW;
			display->visual = fix.visual;
			display->type = fix.type;
			display->type_aux = fix.type_aux;
			display->ypanstep = fix.ypanstep;
			display->ywrapstep = fix.ywrapstep;
			display->line_length = fix.line_length;
			display->can_soft_blank = 1;