添加LCD设备驱动至内核，点击下载代码
tq210_fb.h
#include <linux/module.h>
#include <linux/fb.h>
#include <linux/dma-mapping.h>
#include <linux/clk.h>
static struct fb_info *lcd_info;
unsigned long pseudo_palette[16];
unsigned long *display_control;
volatile unsigned long* gpf0con;
volatile unsigned long* gpf1con;
volatile unsigned long* gpf2con;
volatile unsigned long* gpf3con;
volatile unsigned long* gpd0con;
volatile unsigned long* gpd0dat;
volatile unsigned long* vidcon0;
volatile unsigned long* vidcon1;
volatile unsigned long* vidtcon0;
volatile unsigned long* vidtcon1;
volatile unsigned long* vidtcon2;
volatile unsigned long* wincon0;
volatile unsigned long* vidosd0a;
volatile unsigned long* vidosd0b;
volatile unsigned long* vidosd0c;
volatile unsigned long* vidw00add0b0;
volatile unsigned long* vidw00add1b0;
volatile unsigned long* shodowcon;
struct clk *lcd_clk;
static inline unsigned int chan_to_field(unsigned int chan, struct fb_bitfield *bf)
{
chan &= 0xffff;
chan >>= 16 - bf->length;
return chan << bf->offset;
}
static int lcdfb_setcolreg(unsigned int regno, unsigned int red,
unsigned int green, unsigned int blue,
unsigned int transp, struct fb_info *info)
{
unsigned int val;
if (regno > 16)
return 1;
/* 用red,green,blue三原色构造出val */
val = chan_to_field(red, &info->var.red);
val |= chan_to_field(green, &info->var.green);
val |= chan_to_field(blue, &info->var.blue);
//((u32 *)(info->pseudo_palette))[regno] = val;
pseudo_palette[regno] = val;
return 0;
}
static struct fb_ops lcd_fbops = {
.owner = THIS_MODULE,
.fb_setcolreg = lcdfb_setcolreg,
.fb_fillrect = cfb_fillrect,
.fb_copyarea = cfb_copyarea,
.fb_imageblit = cfb_imageblit,
};
static int lcd_init(void){
int ret;
/*分配fb_info */
lcd_info = framebuffer_alloc(0, NULL);
if(lcd_info == NULL){
printk(KERN_ERR "alloc framebuffer failed!\n");
return -ENOMEM;
}
/* 配置fb_info各成员*/
/* fix */
strcpy(lcd_info->fix.id, "s5pv210_lcd");
lcd_info->fix.smem_len = 800*480*4;
lcd_info->fix.type = FB_TYPE_PACKED_PIXELS;
lcd_info->fix.visual = FB_VISUAL_TRUECOLOR;
lcd_info->fix.line_length = 800*4;
/* var */
lcd_info->var.xres = 800;
lcd_info->var.yres = 480;
lcd_info->var.xres_virtual = 800;
lcd_info->var.yres_virtual = 480;
lcd_info->var.bits_per_pixel = 32;
lcd_info->var.red.offset = 16;
lcd_info->var.red.length = 8;
lcd_info->var.green.offset = 8;
lcd_info->var.green.length = 8;
lcd_info->var.blue.offset = 0;
lcd_info->var.blue.length = 8;
lcd_info->var.activate = FB_ACTIVATE_NOW;
lcd_info->screen_size = 800*480*4;
lcd_info->pseudo_palette = pseudo_palette;
lcd_info->fbops = &lcd_fbops;
/* 配置硬件资源*/
/* 映射内存*/
display_control = ioremap(0xe0107008,4);
gpf0con = ioremap(0xE0200120, 4);
gpf1con = ioremap(0xE0200140, 4);
gpf2con = ioremap(0xE0200160, 4);
gpf3con = ioremap(0xE0200180, 4);
gpd0con = ioremap(0xE02000A0, 4);
gpd0dat = ioremap(0xE02000A4, 4);
vidcon0 = ioremap(0xF8000000, 4);
vidcon1 = ioremap(0xF8000004, 4);
vidtcon0 = ioremap(0xF8000010, 4);
vidtcon1 = ioremap(0xF8000014, 4);
vidtcon2 = ioremap(0xF8000018, 4);
wincon0 = ioremap(0xF8000020, 4);
vidosd0a = ioremap(0xF8000040, 4);
vidosd0b = ioremap(0xF8000044, 4);
vidosd0c = ioremap(0xF8000048, 4);
vidw00add0b0 = ioremap(0xF80000A0, 4);
vidw00add1b0 = ioremap(0xF80000D0, 4);
shodowcon = ioremap(0xF8000034, 4);
/* 配置GPIO*/
*gpf0con = 0x22222222;
*gpf1con = 0x22222222;
*gpf2con = 0x22222222;
*gpf3con = 0x22222222;
*gpd0con &= ~0xf;
*gpd0con |= 0x1;
*gpd0dat |= 1<<0;
*display_control = 2<<0;
/* 使能时钟*/
lcd_clk = clk_get(NULL, "lcd");
if (!lcd_clk || IS_ERR(lcd_clk)) {
printk(KERN_INFO "failed to get lcd clock source\n");
}
clk_enable(lcd_clk);
/* 配置LCD控制器*/
*vidcon0 = (4<<6)|(1<<4);
*vidcon1 = (1<<6)|(1<<5)|(1<<4);
*vidtcon0 = (17<<16)|(26<<8)|(4<<0);
*vidtcon1 = (40<<16)|(214<<8)|(4<<0);
*vidtcon2 = (479<<11)|(799<<0);
*wincon0 &= ~(0xf<<2);
*wincon0 |= (0xb<<2);
*vidosd0a = (0<<11)|(0<<0);
*vidosd0b = (799<<11)|(479<<0);
*vidosd0c = 480*800;
//物理地址
lcd_info->screen_base = dma_alloc_writecombine(NULL,
lcd_info->fix.smem_len, (dma_addr_t *)&(lcd_info->fix.smem_start), GFP_KERNEL);
*vidw00add0b0 = lcd_info->fix.smem_start;
*vidw00add1b0 = lcd_info->fix.smem_start + lcd_info->fix.smem_len;
*shodowcon = 0x1;
//开启状态
*wincon0 |= 1;
*vidcon0 |= 3;
/* 注册fb_info */
ret = register_framebuffer(lcd_info);
return ret;
}
static void lcd_exit(void){
unregister_framebuffer(lcd_info);
dma_free_writecombine(NULL, lcd_info->fix.smem_len,
(void*)lcd_info->screen_base, (dma_addr_t)lcd_info->fix.smem_start);
iounmap(shodowcon);
iounmap(vidw00add1b0);
iounmap(vidw00add0b0);
iounmap(vidosd0c);
iounmap(vidosd0b);
iounmap(vidosd0a);
iounmap(wincon0);
iounmap(vidtcon2);
iounmap(vidtcon1);
iounmap(vidtcon0);
iounmap(vidcon1);
iounmap(vidcon0);
iounmap(gpd0dat);
iounmap(gpd0con);
iounmap(gpf3con);
iounmap(gpf2con);
iounmap(gpf1con);
iounmap(gpf0con);
framebuffer_release(lcd_info);
}
module_init(lcd_init);
module_exit(lcd_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jerry.Gou");
MODULE_DESCRIPTION("TQ210 lcd driver");
将上面的代码在自己的内核环境下编译，然后下载到开发板上试运行即可。
在安装驱动程序前执行指令：
ls /dev/fb*
如果有fb0或者其他fb*存在，应该修改内和配置，取消其他fb的配置（是编译加载\drivers\video\s3c-fb.c导致）
修改\drivers\video\Makefile
obj-$(CONFIG_FB_S3C) += s3c-fb.o 改为 obj-$(CONFIG_FB_S3C) += tq210/ #obj-$(CONFIG_FB_S3C) += s3c-fb.o
在driver目录下添加tq210目录，存放lcd设备文件
tq210目录下添加Makefile文件和Kconfig文件
Makefile
# # Makefile for the s3c framebuffer driver # ifeq ($(CONFIG_FB_S3C),y) obj-$(CONFIG_FB_TQ210) += tq210_fb.o endifKconfig
#
# S3C Video configuration
#
config FB_TQ210
tristate "TQ210 lcd support"
depends on FB
select FB_CFB_FILLRECT
select FB_CFB_COPYAREA
select FB_CFB_IMAGEBLIT
---help---
Currently the suport is only for the TQ210
同时\drivers\video\Kconfig中config FB_CIRRUS前面添加
source "drivers/video/tq210/Kconfig"
如果看不到fb*设备，则可以按照如下步骤进行测试。
测试前还需要修改下内核配置，有两个原因：
(1) 内核默认配置下不支持Frame buffer
(2) 我们的驱动程序中用到了三个函数：
.fb_fillrect = cfb_fillrect, .fb_copyarea = cfb_copyarea, .fb_imageblit = cfb_imageblit,
这三个函数是引用的内核中的函数，不是我们自行实现的。
鉴于上面两个原因，我们需要配置内核支持Frame buffer和列举出的三个函数，另外，内核中并没有直接配置支持这三个函数的选项，权宜之计，修改下drivers/video目录下的Kconfig文件，在config FB项中添加
select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT
添加时一定保证格式正确，参考下该文件下的其他配置项即可。配置完成后执行make menuconfig作如下配置：
Device Drivers ---> Graphics support ---> <*> Support for frame buffer devices ---> <*> TQ210 lcd support测试方法：
(1) 在Linux主机上编译下面的C++程序
#include <iostream>
unsigned long buffer[480][800] = {0};
void put_long_hex(unsigned long v){
for(int i = 0; i != 4; ++i){
std::cout.put(static_cast<char>(0xff&(v>>(8*(3-i)))));
}
}
int main(){
for(int i = 0; i != 480; ++i){
buffer[i][0] = 0x00ff0000;
buffer[i][799] = 0x0000ff00;
}
for(int i = 0; i != 800; ++i){
buffer[0][i] = 0xff000000;
buffer[479][i] = 0x00ffff00;
}
for(int i = 0; i != 480; ++i){
for(int j = 0; j != 800; ++j){
put_long_hex(buffer[i][j]);
}
}
}
编译指令如下：
g++ -o main main.cpp
然后如下方式执行程序：
./main > /nfsroot/rootfs/test.img
我是直接将文件生成在NFS的根文件系统下了，你也可以用其他方式将生成的文件拷贝到开发板运行环境内，然后执行如下指令：
cat test.img > /dev/fb0
这时，就可以在屏幕上看到一个矩形且矩形的四条边颜色不相同。
如果想将驱动编译进内核，并在启动时可以看到小企鹅，可以将上面的驱动拷贝到内核的drivers/video/目录下，命名为tq210_fb.c，然后在该目录下做如下修改：
退回到内核根目录下，执行make menuconfig并按如下方式配置内核Device Drivers ---> Graphics support ---> <*> Support for frame buffer devices ---> <*> TQ210 lcd support [*] Bootup logo ---> [*] Standard black and white Linux logo [*] Standard 16-color Linux logo [*] Standard 224-color Linux logo
然后执行指令make zImage或者make uImage来编译内核，将编译好的内核烧写到开发板或者是放到NFS下即可正常运行。