epson1355fb.c

S3C44B0X下的LCD （framebuffer）驱动资料与相关代码

/*
 * linux/drivers/video/epson1355fb.c
 *	-- Support for the Epson SED1355 LCD/CRT controller
 *
 * Copyright (C) 2000 Philipp Rumpf <[e-mail]>
 *
 * based on linux/drivers/video/skeletonfb.c, which was
 *  Created 28 Dec 1997 by Geert Uytterhoeven
 *
 * 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 (roughly in order of priority):
 * 16 bpp support
 * crt support
 * hw cursor support
 * SwivelView
 */

#include <asm/io.h>
#include <linux/config.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/tty.h>
#include <video/fbcon-cfb8.h>
#include <video/fbcon-mfb.h>
#include <video/fbcon.h>

/* Register defines.  The docs don't seem to provide nice mnemonic names
 * so I made them up myself ... */

#define E1355_PANEL	0x02
#define E1355_DISPLAY	0x0D
#define E1355_MISC	0x1B
#define E1355_GPIO	0x20
#define E1355_LUT_INDEX 0x24
#define E1355_LUT_DATA	0x26

#ifdef CONFIG_SUPERH
#define E1355_REG_BASE	CONFIG_E1355_REG_BASE
#define E1355_FB_BASE	CONFIG_E1355_FB_BASE

static inline u8 e1355_read_reg(int index)
{
	return ctrl_inb(E1355_REG_BASE + index);
}

static inline void e1355_write_reg(u8 data, int index)
{
	ctrl_outb(data, E1355_REG_BASE + index);
}

static inline u16 e1355_read_reg16(int index)
{
	return e1355_read_reg(index) + (e1355_read_reg(index+1) << 8);
}

static inline void e1355_write_reg16(u16 data, int index)
{
	e1355_write_reg((data&0xff), index);
	e1355_write_reg(((data>>8)&0xff), index + 1);
}
#else
#error unknown architecture
#endif

struct e1355fb_info {
	struct fb_info_gen gen;
};

static int current_par_valid = 0;
static struct display disp;

static struct fb_var_screeninfo default_var;

int e1355fb_init(void);
int e1355fb_setup(char*);
static int e1355_encode_var(struct fb_var_screeninfo *var, const void *par,
			    struct fb_info_gen *info);
/* ------------------- chipset specific functions -------------------------- */


static void disable_hw_cursor(void)
{
	u8 curs;

	curs = e1355_read_reg(0x27);
	curs &= ~0xc0;
	e1355_write_reg(curs, 0x27);
}

static void e1355_detect(void)
{
	u8 rev;

	e1355_write_reg(0x00, E1355_MISC);

	rev = e1355_read_reg(0x00);

	if ((rev & 0xfc) != 0x0c) {
		printk(KERN_WARNING "Epson 1355 not detected\n");
	}

	/* XXX */
	disable_hw_cursor();

	e1355_encode_var(&default_var, NULL, NULL);
}

struct e1355_par {
	u32 xres;
	u32 yres;

	int bpp;
	int mem_bpp;

	u32 panel_xres;
	u32 panel_yres;
	
	int panel_width;
	int panel_ymul;
};

static int e1355_encode_fix(struct fb_fix_screeninfo *fix,
			    const void *raw_par,
			    struct fb_info_gen *info)
{
	const struct e1355_par *par = raw_par;
	
	memset(fix, 0, sizeof *fix);
	
	fix->type= FB_TYPE_PACKED_PIXELS;

	if (!par)
		BUG();

	if (par->bpp == 1) {
		fix->visual = FB_VISUAL_MONO10;
	} else if (par->bpp <= 8) {
		fix->visual = FB_VISUAL_PSEUDOCOLOR;
	} else {
		fix->visual = FB_VISUAL_TRUECOLOR;
	}

	return 0;
}

static int e1355_set_bpp(struct e1355_par *par, int bpp)
{
	int code;
	u8 disp;
	u16 bytes_per_line;

	switch(bpp) {
	case 1:
		code = 0; break;
	case 2:
		code = 1; break;
	case 4:
		code = 2; break;
	case 8:
		code = 3; break;
	case 16:
		code = 5; break;
	default:
		return -EINVAL; break;
	}

	disp = e1355_read_reg(E1355_DISPLAY);
	disp &= ~0x1c;
	disp |= code << 2;
	e1355_write_reg(disp, E1355_DISPLAY);
	
	bytes_per_line = (par->xres * bpp) >> 3;
	
	e1355_write_reg16(bytes_per_line, 0x16);

	par->bpp = bpp;

	return 0;
}
		
static int e1355_decode_var(const struct fb_var_screeninfo *var,
			    void *raw_par,
			    struct fb_info_gen *info)
{
	struct e1355_par *par = raw_par;
	int ret;

	if (!par)
		BUG();

	/*
	 * Don't allow setting any of these yet: xres and yres don't
	 * make sense for LCD panels; xres_virtual and yres_virtual
	 * should be supported fine by our hardware though.
	 */
	if (var->xres != par->xres ||
	    var->yres != par->yres ||
	    var->xres != var->xres_virtual ||
	    var->yres != var->yres_virtual ||
	    var->xoffset != 0 ||
	    var->yoffset != 0)
		return -EINVAL;

	if(var->bits_per_pixel != par->bpp) {
		ret = e1355_set_bpp(par, var->bits_per_pixel);

		if (ret)
			goto out_err;
	}
		
	return 0;

 out_err:
	return ret;
}

static void dump_panel_data(void)
{
	u8 panel = e1355_read_reg(E1355_PANEL);
	int width[2][4] = { { 4, 8, 16, -1 }, { 9, 12, 16, -1 } };

	printk("%s %s %s panel, width %d bits\n",
	       panel & 2 ? "dual" : "single",
	       panel & 4 ? "color" : "mono",
	       panel & 1 ? "TFT" : "passive",
	       width[panel&1][(panel>>4)&3]);

	printk("resolution %d x %d\n",
	       (e1355_read_reg(0x04) + 1) * 8,
	       ((e1355_read_reg16(0x08) + 1) * (1 + ((panel & 3) == 2))));
}

static int e1355_bpp_to_var(int bpp, struct fb_var_screeninfo *var)
{
	switch(bpp) {
	case 1:
	case 2:
	case 4:
	case 8:
		var->bits_per_pixel = bpp;
		var->red.offset = var->green.offset = var->blue.offset = 0;
		var->red.length = var->green.length = var->blue.length = bpp;
		break;
	case 16:
		var->bits_per_pixel = 16;
		var->red.offset = 11;
		var->red.length = 5;
		var->green.offset = 5;
		var->green.length = 6;
		var->blue.offset = 0;
		var->blue.length = 5;
		break;
	}

	return 0;
}

static int e1355_encode_var(struct fb_var_screeninfo *var, const void *raw_par,
			    struct fb_info_gen *info)
{
	u8 panel, display;
	u32 xres, xres_virtual, yres;
	static int width[2][4] = { { 4, 8, 16, -1 }, { 9, 12, 16, -1 } };
	static int bpp_tab[8] = { 1, 2, 4, 8, 15, 16 };
	int bpp, hw_bpp;
	int is_color, is_dual, is_tft;
	int lcd_enabled, crt_enabled;

	panel = e1355_read_reg(E1355_PANEL);
	display = e1355_read_reg(E1355_DISPLAY);

	is_color = (panel & 0x04) != 0;
	is_dual  = (panel & 0x02) != 0;
	is_tft   = (panel & 0x01) != 0;

	bpp = bpp_tab[(display>>2)&7]; 
	e1355_bpp_to_var(bpp, var);

	crt_enabled = (display & 0x02) != 0;
	lcd_enabled = (display & 0x02) != 0;

	hw_bpp = width[is_tft][(panel>>4)&3];

	xres = e1355_read_reg(0x04) + 1;
	yres = e1355_read_reg16(0x08) + 1;
	
	xres *= 8;
	/* talk about weird hardware .. */
	yres *= (is_dual && !crt_enabled) ? 2 : 1;

	xres_virtual = e1355_read_reg16(0x16);
	/* it's in 2-byte words initially */
	xres_virtual *= 16;
	xres_virtual /= var->bits_per_pixel;

	var->xres = xres;
	var->yres = yres;
	var->xres_virtual = xres_virtual;
	var->yres_virtual = yres;

	var->xoffset = var->yoffset = 0;

	var->grayscale = !is_color;
	
	return 0;
}

#define is_dual(panel) (((panel)&3)==2)

static void get_panel_data(struct e1355_par *par)
{
	u8 panel;
	int width[2][4] = { { 4, 8, 16, -1 }, { 9, 12, 16, -1 } };

	panel = e1355_read_reg(E1355_PANEL);

	par->panel_width = width[panel&1][(panel>>4)&3];
	par->panel_xres = (e1355_read_reg(0x04) + 1) * 8;
	par->panel_ymul = is_dual(panel) ? 2 : 1;
	par->panel_yres = ((e1355_read_reg16(0x08) + 1)
			   * par->panel_ymul);
}

static void e1355_get_par(void *raw_par, struct fb_info_gen *info)
{
	struct e1355_par *par = raw_par;

	get_panel_data(par);
}

static void e1355_set_par(const void *par, struct fb_info_gen *info)
{
}

static int e1355_getcolreg(unsigned regno, unsigned *red, unsigned *green,
			   unsigned *blue, unsigned *transp,
			   struct fb_info *info)
{
	u8 r, g, b;

	e1355_write_reg(regno, E1355_LUT_INDEX);
	r = e1355_read_reg(E1355_LUT_DATA);
	g = e1355_read_reg(E1355_LUT_DATA);
	b = e1355_read_reg(E1355_LUT_DATA);

	*red = r << 8;
	*green = g << 8;
	*blue = b << 8;

	return 0;
}

static int e1355_setcolreg(unsigned regno, unsigned red, unsigned green,
			   unsigned blue, unsigned transp,
			   struct fb_info *info)
{
	u8 r = (red >> 8) & 0xf0;
	u8 g = (green>>8) & 0xf0;
	u8 b = (blue>> 8) & 0xf0;

	e1355_write_reg(regno, E1355_LUT_INDEX);
	e1355_write_reg(r, E1355_LUT_DATA);
	e1355_write_reg(g, E1355_LUT_DATA);
	e1355_write_reg(b, E1355_LUT_DATA);
	
	return 0;
}

static int e1355_pan_display(const struct fb_var_screeninfo *var,
			     struct fb_info_gen *info)
{
	BUG();
	
	return -EINVAL;
}

/*
 * The AERO_HACKS parts disable/enable the backlight on the Compaq Aero 8000.
 * I'm not sure they aren't dangerous to the hardware, so be warned.
 */
#undef AERO_HACKS

static int e1355_blank(int blank_mode, struct fb_info_gen *info)
{
	u8 disp;

	switch (blank_mode) {
	case VESA_NO_BLANKING:
		disp = e1355_read_reg(E1355_DISPLAY);
		disp |= 1;
		e1355_write_reg(disp, E1355_DISPLAY);
 		
#ifdef AERO_HACKS
		e1355_write_reg(0x6, 0x20);
#endif
		break;

	case VESA_VSYNC_SUSPEND:
	case VESA_HSYNC_SUSPEND:
	case VESA_POWERDOWN:
		disp = e1355_read_reg(E1355_DISPLAY);
		disp &= ~1;
		e1355_write_reg(disp, E1355_DISPLAY);

#ifdef AERO_HACKS
		e1355_write_reg(0x0, 0x20);
#endif
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

static struct display_switch e1355_dispsw;

static void e1355_set_disp(const void *unused, struct display *disp,
			   struct fb_info_gen *info)
{
	struct display_switch *d;

	disp->screen_base = (void *)E1355_FB_BASE;
	disp->dispsw = &e1355_dispsw;
	
	switch(disp->var.bits_per_pixel) {
#ifdef FBCON_HAS_MFB
	case 1:
		d = &fbcon_mfb; break;
#endif	       
#ifdef FBCON_HAS_CFB8
	case 8:
		d = &fbcon_cfb8; break;
#endif
	default:
		BUG(); break;
	}

	memcpy(&e1355_dispsw, d, sizeof *d);

	/* reading is terribly slow for us */
#if 0 /* XXX: need to work out why this doesn't work */
	e1355_dispsw.bmove = fbcon_redraw_bmove;
#endif
}

/* ------------ Interfaces to hardware functions ------------ */


struct fbgen_hwswitch e1355_switch = {
	detect:		e1355_detect,
	encode_fix:	e1355_encode_fix,
	decode_var:	e1355_decode_var,
	encode_var:	e1355_encode_var,
	get_par:	e1355_get_par,
	set_par:	e1355_set_par,
	getcolreg:	e1355_getcolreg,
	setcolreg:	e1355_setcolreg,
	pan_display:	e1355_pan_display,
	blank:		e1355_blank,
	set_disp:	e1355_set_disp,
};


/* ------------ Hardware Independent Functions ------------ */


static struct fb_ops e1355fb_ops = {
	owner:		THIS_MODULE,
	fb_get_fix:	fbgen_get_fix,
	fb_get_var:	fbgen_get_var,
	fb_set_var:	fbgen_set_var,
	fb_get_cmap:	fbgen_get_cmap,
	fb_set_cmap:	fbgen_set_cmap,
	fb_pan_display:	fbgen_pan_display,
};

static struct e1355fb_info fb_info;

int __init e1355fb_setup(char *str)
{
	return 0;
}

int __init e1355fb_init(void)
{
	fb_info.gen.fbhw = &e1355_switch;
	fb_info.gen.fbhw->detect();
	strcpy(fb_info.gen.info.modename, "SED1355");
	fb_info.gen.info.changevar = NULL;
	fb_info.gen.info.node = -1;
	fb_info.gen.info.fbops = &e1355fb_ops;
	fb_info.gen.info.disp = &disp;
	fb_info.gen.parsize = sizeof(struct e1355_par);
	fb_info.gen.info.switch_con = &fbgen_switch;
	fb_info.gen.info.updatevar = &fbgen_update_var;
	fb_info.gen.info.blank = &fbgen_blank;
	fb_info.gen.info.flags = FBINFO_FLAG_DEFAULT;
	/* This should give a reasonable default video mode */
	fbgen_get_var(&disp.var, -1, &fb_info.gen.info);
	fbgen_do_set_var(&disp.var, 1, &fb_info.gen);
	fbgen_set_disp(-1, &fb_info.gen);
	if (disp.var.bits_per_pixel > 1) 
		fbgen_install_cmap(0, &fb_info.gen);
	if (register_framebuffer(&fb_info.gen.info) < 0)
		return -EINVAL;
	printk(KERN_INFO "fb%d: %s frame buffer device\n", GET_FB_IDX(fb_info.gen.info.node),
	       fb_info.gen.info.modename);

	return 0;
}


    /*
     *  Cleanup
     */

void e1355fb_cleanup(struct fb_info *info)
{
	/*
	 *  If your driver supports multiple boards, you should unregister and
	 *  clean up all instances.
	 */
	
	unregister_framebuffer(info);
	/* ... */
}

MODULE_LICENSE("GPL");