mini2440驱动-lcd驱动显示

开发板linux内核：linux-2.6.39
lcd型号：统宝 3.5 LCD

    参考《mini2440 linux移植开发实战指南.pdf》
    
        Linux-2.6.32.2 内核已经支持S3C2440 的LCD 控制器驱动，但在此我们先介绍一下关于2440 LCD控制器以及驱动相关的LCD 的一些基础知识。 
        注意：在此我们只讨论TFT LCD，也就是真彩屏。 
        LCD 驱动中最关键的就是时钟频率( Clock frequency) 的设置，时钟频率设置不对，LCD的显示就会闪，或者根本没有显示。一般LCD的Datasheet 上会写有一个推荐的频率，比如mini2440 所用的统宝3.5”LCD ，在它的数据手册第13页，有这样一个表格： 


2、在linux-2.6.39/arch/arm/mach-s3c2440/mach-my2440.c 中修改对lcd控制寄存器的配置

/* LCD driver info */
#if defined(CONFIG_FB_S3C2410_N240320)

#define LCD_WIDTH 240
#define LCD_HEIGHT 320
#define LCD_PIXCLOCK 100000

#define LCD_RIGHT_MARGIN 36
#define LCD_LEFT_MARGIN 19
#define LCD_HSYNC_LEN 5

#define LCD_UPPER_MARGIN 1
#define LCD_LOWER_MARGIN 5
#define LCD_VSYNC_LEN 1

#elif defined(CONFIG_FB_S3C2410_W320240)
#define LCD_WIDTH 320
#define LCD_HEIGHT 240
#define LCD_PIXCLOCK 170000

#define LCD_RIGHT_MARGIN 0x44
#define LCD_LEFT_MARGIN 0x04
#define LCD_HSYNC_LEN 0x01

#define LCD_UPPER_MARGIN 10
#define LCD_LOWER_MARGIN 4
#define LCD_VSYNC_LEN 1

#define LCD_CON5 (S3C2410_LCDCON5_FRM565 | S3C2410_LCDCON5_INVVFRAME | S3C2410_LCDCON5_INVVLINE | S3C2410_LCDCON5_HWSWP )

#elif defined(CONFIG_FB_S3C2410_N480272)

#define LCD_WIDTH 480
#define LCD_HEIGHT 272
#define LCD_PIXCLOCK 100000

#define LCD_RIGHT_MARGIN 36
#define LCD_LEFT_MARGIN 19
#define LCD_HSYNC_LEN 5

#define LCD_UPPER_MARGIN 1
#define LCD_LOWER_MARGIN 5
#define LCD_VSYNC_LEN 1

#elif defined(CONFIG_FB_S3C2410_TFT640480)
#define LCD_WIDTH 640
#define LCD_HEIGHT 480
#define LCD_PIXCLOCK 40000

#define LCD_RIGHT_MARGIN 67
#define LCD_LEFT_MARGIN 40
#define LCD_HSYNC_LEN 31

#define LCD_UPPER_MARGIN 5
#define LCD_LOWER_MARGIN 25
#define LCD_VSYNC_LEN 1

#elif defined(CONFIG_FB_S3C2410_T240320)
#define LCD_WIDTH 240
#define LCD_HEIGHT 320
#define LCD_PIXCLOCK 170000
#define LCD_RIGHT_MARGIN 25
#define LCD_LEFT_MARGIN 0
#define LCD_HSYNC_LEN 4
#define LCD_UPPER_MARGIN 1
#define LCD_LOWER_MARGIN 4
#define LCD_VSYNC_LEN 1
#define LCD_CON5 (S3C2410_LCDCON5_FRM565 | S3C2410_LCDCON5_INVVDEN | S3C2410_LCDCON5_INVVFRAME | S3C2410_LCDCON5_INVVLINE | S3C2410_LCDCON5_INVVCLK | S3C2410_LCDCON5_HWSWP )

#elif defined(CONFIG_FB_S3C2410_X240320)
#define LCD_WIDTH 240
#define LCD_HEIGHT 320
#define LCD_PIXCLOCK 170000
#define LCD_RIGHT_MARGIN 25
#define LCD_LEFT_MARGIN 0
#define LCD_HSYNC_LEN 4
#define LCD_UPPER_MARGIN 0
#define LCD_LOWER_MARGIN 4
#define LCD_VSYNC_LEN 9
#define LCD_CON5 (S3C2410_LCDCON5_FRM565 | S3C2410_LCDCON5_INVVDEN | S3C2410_LCDCON5_INVVFRAME | S3C2410_LCDCON5_INVVLINE | S3C2410_LCDCON5_INVVCLK | S3C2410_LCDCON5_HWSWP )

#elif defined(CONFIG_FB_S3C2410_TFT800480)
#define LCD_WIDTH 800
#define LCD_HEIGHT 480
#define LCD_PIXCLOCK 40000

#define LCD_RIGHT_MARGIN 67
#define LCD_LEFT_MARGIN 40
#define LCD_HSYNC_LEN 31

#define LCD_UPPER_MARGIN 25
#define LCD_LOWER_MARGIN 5
#define LCD_VSYNC_LEN 1

#elif defined(CONFIG_FB_S3C2410_VGA1024768)
#define LCD_WIDTH 1024
#define LCD_HEIGHT 768
#define LCD_PIXCLOCK 80000

#define LCD_RIGHT_MARGIN 15
#define LCD_LEFT_MARGIN 199
#define LCD_HSYNC_LEN 15

#define LCD_UPPER_MARGIN 1
#define LCD_LOWER_MARGIN 1
#define LCD_VSYNC_LEN 1
#define LCD_CON5 (S3C2410_LCDCON5_FRM565 | S3C2410_LCDCON5_HWSWP)

#endif

#if defined (LCD_WIDTH)

static struct s3c2410fb_display my2440_lcd_cfg __initdata = {

#if !defined (LCD_CON5)
    .lcdcon5    = S3C2410_LCDCON5_FRM565 |
              S3C2410_LCDCON5_INVVLINE |
              S3C2410_LCDCON5_INVVFRAME |
              S3C2410_LCDCON5_PWREN |
              S3C2410_LCDCON5_HWSWP,
#else
    .lcdcon5    = LCD_CON5,
#endif

    .type        = S3C2410_LCDCON1_TFT,

    .width        = LCD_WIDTH,
    .height        = LCD_HEIGHT,

    .pixclock    = LCD_PIXCLOCK,
    .xres        = LCD_WIDTH,
    .yres        = LCD_HEIGHT,
    .bpp        = 16,
    .left_margin    = LCD_LEFT_MARGIN + 1,
    .right_margin    = LCD_RIGHT_MARGIN + 1,
    .hsync_len    = LCD_HSYNC_LEN + 1,
    .upper_margin    = LCD_UPPER_MARGIN + 1,
    .lower_margin    = LCD_LOWER_MARGIN + 1,
    .vsync_len    = LCD_VSYNC_LEN + 1,
};


static struct s3c2410fb_mach_info my2440_fb_info __initdata = {
    .displays    = &my2440_lcd_cfg,
    .num_displays    = 1,
    .default_display = 0,

    .gpccon = 0xaa955699,
    .gpccon_mask = 0xffc003cc,
    .gpcup = 0x0000ffff,
    .gpcup_mask = 0xffffffff,

    .gpdcon = 0xaa95aaa1,
    .gpdcon_mask = 0xffc0fff0,
    .gpdup = 0x0000faff,
    .gpdup_mask = 0xffffffff,


    .lpcsel        = 0xf82,
};

#endif

3、重新编译内核并下载到开发板上，上电系统启动后可以看到LCD亮起，并且出现小企鹅图标。