u-boot-2009.08在mini2440上的移植（七）---增加LCD显示功能

移植环境

1，主机环境：VMare下CentOS 5.5 ，1G内存。

2，集成开发环境：Elipse IDE

3，编译编译环境：arm-linux-gcc v4.4.3，arm-none-eabi-gcc v4.5.1。

4，开发板：mini2440，2M nor flash，128M nand flash。

5，u-boot版本：u-boot-2009.08

6，参考文章：

http://blogold.chinaunix.net/u3/101649/showart.php?id=2105215

http://blog.chinaunix.net/space.php?uid=23787856&do=blog&id=115382

http://blogimg.chinaunix.net/blog/upfile2/100811115954.pdf

7.1添加 LCD 显示功能

对于这个 LCD 的支持是参考Openmoko 的代码移植的。Openmoko 的GTA2 使用的是S3C2442 的CPU，在LCD 控制器上是一样的。而GTA2 在U-boot 的可以在LCD 上显示字符，而且对于软件分层的U-boot 来说，只要将底层驱动移植过来并调整好初始化参数就可以在LCD 上显示console。下图是LCD驱动软件分层执行流程示意。可以看到LCD在执行时最终调用的是底层的board_video_init()函数，其主要作用是对LCD控制寄存器进行初始化。可由用户根据实际LCD硬件编写。

由于友善之臂使用了两种屏，他们在一个参数上有很小的差别，而屏有不可以通过程序去识别，所以只能简单的通过Nand Flash配置来区分导入的参数（64MB Nand 的板子使用的都是NEC 的，其他的都是统宝的）。这个功能的移植修改了5 个文件（包括drivers/video/Makefile，以及前面已经修改过的board/samsung/mini2440/mini2440.c 文件）。

【1】在/drivers/video/下添加一个驱动文件名为s3c2410_fb.c，将下面内容粘贴进去：

/*
* (C) Copyright 2006 by OpenMoko, Inc.
* Author: Harald Welte
*
* 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

#if defined(CONFIG_VIDEO_S3C2410)

#include
#include "videomodes.h"
#include
/*
* 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 ("%sn", 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 = 240;
pGD->winSizeY = pGD->plnSizeY = 320;
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 */