ARM+LINUX移植攻略（十）支持东华 3.5寸LCD输出console信息和BMP图片、logo

哈尔滨理工大学软件工程专业08-7李万鹏原创作品，转载请标明出处

http://blog.csdn.net/woshixingaaa/archive/2011/02/19/6194637.aspx

由于linux启动代码，仍然出现乱码，而我将启动信息输出到lcd就没有乱码。暂时这个问题还没有解决，lcd其实早已完成，今天整理下，再解决那个问题。

下面是我绘制的主要的lcd驱动调用流程图。start_armboot()在lib_arm/board.c中，stdio_init()在common/stdio.cdrv_video_init(),video_init(),video_logo (),video_fb_address(）在drivers/video/cfb_console.c中，video_hw_init()在drivers/video/s3c2410_fb.c中，board_video_init()在board/samsung/TE2440II/TE2440II.c。

最终调用了board_video_init()函数，这个函数由我们自己来编写，由于以前写过裸机的lcd程序，所以时序就可以直接拿来用，不用调了，哈哈。在这个函数中主要还是对那5个lcd的控制寄存器进行初始化。这里要注意根据不同的屏，进行x,y的调整，我用的是东华WXCAT35-TG3#001，主要就是初始化一个GraphicDevice *pGD结构体。

#define MVAL		(0)
#define MVAL_USED 	(0)		//0=each frame   1=rate by MVAL
#define INVVDEN		(0)		//0=normal       1=inverted
#define BSWP		(0)		//Byte swap control
#define HWSWP		(0)		//Half word swap control
//TFT 240320
#define LCD_XSIZE_TFT_240320 	(320)	
#define LCD_YSIZE_TFT_240320 	(240)
//TFT240320
#define HOZVAL_TFT_240320	(LCD_XSIZE_TFT_240320-1)
#define LINEVAL_TFT_240320	(LCD_YSIZE_TFT_240320-1)
//Timing parameter for WXCAT35-TG3#001"
#define VBPD_240320		(3)		
#define VFPD_240320		(5)
#define VSPW_240320		(15)
#define HBPD_240320		(58)
#define HFPD_240320		(15)
#define HSPW_240320_WXCAT35	(8)  //Adjust the horizontal displacement of the screen 
#define CLKVAL_TFT_240320	(7) 	
//FCLK=405MHz,HCLK=101.25MHz,VCLK=4602272Hz
void board_video_init(GraphicDevice *pGD) 
{ 
    S3C24X0_LCD * const lcd = S3C24X0_GetBase_LCD(); 
	  S3C2410_NAND * const nand = S3C2410_GetBase_NAND();
    /* FIXME: select LCM type by env variable */ 
	 
	/* Configuration for GTA01 LCM on QT2410 */ 
	lcd->LCDCON1 = 0x00000778; /* CLKVAL=7, BPPMODE=16bpp, TFT, ENVID=0 */ 
	lcd->LCDCON2 = (VBPD_240320<<24)|(LINEVAL_TFT_240320<<14)|(VFPD_240320<<6)|(VSPW_240320); 
	lcd->LCDCON3 = (HBPD_240320<<19)|(HOZVAL_TFT_240320<<8)|(HFPD_240320); 
	lcd->LCDCON4 = (MVAL<<8)|(HSPW_240320_WXCAT35);
	lcd->LCDCON5 = 0x00000f09; 
	lcd->LPCSEL  = 0x00000000; 
}

明白上边的流程后一切变得很简单，只要根据自己的屏调整好时序就行了。添加一个驱动文件这个是一个外国的牛人已经写好的。在drivers/video/下添加s3c2410_fb.c。代码如下：

/*
* (C) Copyright 2006 by OpenMoko, Inc.
* Author: Harald Welte <[e-mail]>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#if defined(CONFIG_VIDEO_S3C2410)
#include <video_fb.h>
#include "videomodes.h"
#include <s3c2410.h>
/*
* Export Graphic Device
*/
GraphicDevice smi;
#define VIDEO_MEM_SIZE 0x200000 /* 240x320x16bit = 0x25800 bytes */
extern void board_video_init(GraphicDevice *pGD);
/*******************************************************************************
*
* Init video chip with common Linux graphic modes (lilo)
*/
void *video_hw_init (void)
{
S3C24X0_LCD * const lcd = S3C24X0_GetBase_LCD();
GraphicDevice *pGD = (GraphicDevice *)&smi;
int videomode;
unsigned long t1, hsynch, vsynch;
char *penv;
int tmp, i, bits_per_pixel;
struct ctfb_res_modes *res_mode;
struct ctfb_res_modes var_mode;
// unsigned char videoout;
/* Search for video chip */
printf("Video: ");
tmp = 0;
videomode = CFG_SYS_DEFAULT_VIDEO_MODE;
/* get video mode via environment */
if ((penv = getenv ("videomode")) != NULL) {
/* deceide if it is a string */
if (penv[0] <= '9') {
videomode = (int) simple_strtoul (penv, NULL, 16);
tmp = 1;
}
} else {
tmp = 1;
}
if (tmp) {
/* parameter are vesa modes */
/* search params */
for (i = 0; i < VESA_MODES_COUNT; i++) {
if (vesa_modes[i].vesanr == videomode)
break;
}
if (i == VESA_MODES_COUNT) {
printf ("no VESA Mode found, switching to mode 0x%x ",
CFG_SYS_DEFAULT_VIDEO_MODE);
i = 0;
}
res_mode =
(struct ctfb_res_modes *) &res_mode_init[vesa_modes[i].
resindex];
bits_per_pixel = vesa_modes[i].bits_per_pixel;
} 
else {
res_mode = (struct ctfb_res_modes *) &var_mode;
bits_per_pixel = video_get_params (res_mode, penv);
}
/* calculate hsynch and vsynch freq (info only) */
t1 = (res_mode->left_margin + res_mode->xres +
res_mode->right_margin + res_mode->hsync_len) / 8;
t1 *= 8;
t1 *= res_mode->pixclock;
t1 /= 1000;
hsynch = 1000000000L / t1;
t1 *=
(res_mode->upper_margin + res_mode->yres +
res_mode->lower_margin + res_mode->vsync_len);
t1 /= 1000;
vsynch = 1000000000L / t1;
/* fill in Graphic device struct */
sprintf (pGD->modeIdent, "%dx%dx%d %ldkHz %ldHz", res_mode->xres,
res_mode->yres, bits_per_pixel, (hsynch / 1000),
(vsynch / 1000));
printf ("%s/n", pGD->modeIdent);
pGD->winSizeX = res_mode->xres;
pGD->winSizeY = res_mode->yres;
pGD->plnSizeX = res_mode->xres;
pGD->plnSizeY = res_mode->yres;
switch (bits_per_pixel) {
case 8:
pGD->gdfBytesPP = 1;
pGD->gdfIndex = GDF__8BIT_INDEX;
break;
case 15:
pGD->gdfBytesPP = 2;
pGD->gdfIndex = GDF_15BIT_555RGB;
break;
case 16:
pGD->gdfBytesPP = 2;
pGD->gdfIndex = GDF_16BIT_565RGB;
break;
case 24:
pGD->gdfBytesPP = 3;
pGD->gdfIndex = GDF_24BIT_888RGB;
break;
}
/* statically configure settings */
pGD->winSizeX = pGD->plnSizeX = 320;
pGD->winSizeY = pGD->plnSizeY = 240;
pGD->gdfBytesPP = 2;
pGD->gdfIndex = GDF_16BIT_565RGB;
pGD->frameAdrs = LCD_VIDEO_ADDR;
pGD->memSize = VIDEO_MEM_SIZE;
board_video_init(pGD);
lcd->LCDSADDR1 = pGD->frameAdrs >> 1;
/* This marks the end of the frame buffer. */
lcd->LCDSADDR2 = (lcd->LCDSADDR1&0x1fffff) + (pGD->winSizeX+0) * pGD->winSizeY;
lcd->LCDSADDR3 = (pGD->winSizeX & 0x7ff);
/* Clear video memory */
memset((void *)pGD->frameAdrs, 0, pGD->memSize);
/* Enable Display */
lcd->LCDCON1 |= 0x01; /* ENVID = 1 */
return ((void*)&smi);
}
void
video_set_lut (unsigned int index, /* color number */
unsigned char r, /* red */
unsigned char g, /* green */
unsigned char b /* blue */
)
{
}
#endif /* CONFIG_VIDEO_S3C2410 */

在你的配置头文件中添加如下宏定义：

#define CONFIG_CMD_BMP
#define CONFIG_VIDEO
#define CONFIG_VIDEO_S3C2410
#define CONFIG_VIDEO_LOGO
#define VIDEO_FB_16BPP_PIXEL_SWAP
#define CONFIG_VIDEO_SW_CURSOR
#define CONFIG_VIDEO_BMP_LOGO

这样就基本完成了，重新启动一下是不是就显示出samsung的logo了。如果先改成自己喜欢的图片，修改tools/logos/denx.bmp，记住一定是是8bpp的bmp图，修改Makefile文件，修改/tools目录下的Makefile文件，大约是44~46行，

ifeq ($(LOGO_BMP),)
LOGO_BMP= logos/denx.bmp
endif

把 denx.bmp 替换为你需要显示的logo图片的文件名，保存退出，重新编译uboot。图片的转化方法，在终端输入命令：

jpegtopnm $1 | ppmquant 31 | ppmtobmp -bpp 8 > $2

使用方法： （脚本名） （ 待处理的JPG图片名） （输出文件名）

这样就可以显示出你自己喜欢的logo图片了。

如果想将串口的打印信息显示在lcd上，添加环境变量。

#define	CONFIG_EXTRA_ENV_SETTINGS	/				
	"stdin=serial/0"		/			
	"stdout=vga"			/
	"stderr=serial/0"		/			

只要让stdout等于vga就可以了。在lib_arm/board.c文件中可以看到console_init初始化两次，我们修改的影响第二次的初始化，第一次的不影响，所以还会有部分输出信息显示在串口上的。Lcd就到这里，有什么问题我再及时改正吧。