嵌入式Linux之我行——S3C2440上LCD驅(qū)動(dòng)(FrameBuffer)實(shí)例開發(fā)講解

structfb_info{
intnode;
intflags;
structfb_var_screeninfo var;
structfb_fix_screeninfo fix;
structfb_monspecs monspecs;
structwork_structqueue;
structfb_pixmap pixmap;
structfb_pixmap sprite;
structfb_cmap cmap;
structfb_videomode*mode;

#ifdefCONFIG_FB_BACKLIGHT
structbacklight_device*bl_dev;
structmutex bl_curve_mutex;
u8 bl_curve[FB_BACKLIGHT_LEVELS];
#endif
#ifdefCONFIG_FB_DEFERRED_IO
structdelayed_work deferred_work;
structfb_deferred_io*fbdefio;
#endif

structfb_ops*fbops;
structdevice*device;
structdevice*dev;
intclass_flag;
#ifdefCONFIG_FB_TILEBLITTING
structfb_tile_ops*tileops;
#endif
char__iomem*screen_base;
unsignedlongscreen_size;
void*pseudo_palette;
#defineFBINFO_STATE_RUNNING0
#defineFBINFO_STATE_SUSPENDED1
u32 state;
void*fbcon_par;
void*par;
};

structfb_var_screeninfo{
__u32 xres;
__u32 yres;
__u32 xres_virtual;
__u32 yres_virtual;
__u32 xoffset;
__u32 yoffset;
__u32 bits_per_pixel;
__u32 grayscale;

structfb_bitfield red;
structfb_bitfield green;
structfb_bitfield blue;
structfb_bitfield transp;

__u32 nonstd;
__u32 activate;
__u32 height;
__u32 width;
__u32 accel_flags;


__u32 pixclock;
__u32 left_margin;
__u32 right_margin;
__u32 upper_margin;
__u32 lower_margin;
__u32 hsync_len;
__u32 vsync_len;
__u32 sync;
__u32 vmode;
__u32rotate;
__u32 reserved[5];
};

structfb_fix_screeninfo{
charid[16];
unsignedlongsmem_start;
__u32 smem_len;
__u32 type;
__u32 type_aux;
__u32 visual;
__u16 xpanstep;
__u16 ypanstep;
__u16 ywrapstep;
__u32 line_length;
unsignedlongmmio_start;
__u32 mmio_len;
__u32 accel;
__u16 reserved[3];
};

structfb_ops{

structmodule*owner;

//檢查可變參數(shù)并進(jìn)行設(shè)置
int(*fb_check_var)(structfb_var_screeninfo*var,structfb_info*info);

//根據(jù)設(shè)置的值進(jìn)行更新，使之有效
int(*fb_set_par)(structfb_info*info);

//設(shè)置顏色寄存器
int(*fb_setcolreg)(unsignedregno,unsignedred,unsignedgreen,
unsignedblue,unsignedtransp,structfb_info*info);

//顯示空白
int(*fb_blank)(intblank,structfb_info*info);

//矩形填充
void(*fb_fillrect)(structfb_info*info,conststructfb_fillrect*rect);

//復(fù)制數(shù)據(jù)
void(*fb_copyarea)(structfb_info*info,conststructfb_copyarea*region);

//圖形填充
void(*fb_imageblit)(structfb_info*info,conststructfb_image*image);
};

//LCD控制器的資源信息
staticstructresource s3c_lcd_resource[]={
[0]={
.start=S3C24XX_PA_LCD,//控制器IO端口開始地址
.end=S3C24XX_PA_LCD+S3C24XX_SZ_LCD-1,//控制器IO端口結(jié)束地址
.flags=IORESOURCE_MEM,//標(biāo)識(shí)為L(zhǎng)CD控制器IO端口，在驅(qū)動(dòng)中引用這個(gè)就表示引用IO端口
},
[1]={
.start=IRQ_LCD,//LCD中斷
.end=IRQ_LCD,
.flags=IORESOURCE_IRQ,//標(biāo)識(shí)為L(zhǎng)CD中斷
}
};

staticu64 s3c_device_lcd_dmamask=0xffffffffUL;

structplatform_device s3c_device_lcd={
.name="s3c2410-lcd",//作為平臺(tái)設(shè)備的LCD設(shè)備名
.id=-1,
.num_resources=ARRAY_SIZE(s3c_lcd_resource),//資源數(shù)量
.resource=s3c_lcd_resource,//引用上面定義的資源
.dev={
.dma_mask=&s3c_device_lcd_dmamask,
.coherent_dma_mask=0xffffffffUL
}
};

EXPORT_SYMBOL(s3c_device_lcd);//導(dǎo)出定義的LCD平臺(tái)設(shè)備，好在mach-smdk2440.c的smdk2440_devices[]中添加到平臺(tái)設(shè)備列表中

//LCD硬件的配置信息，注意這里我使用的LCD是NEC 3.5寸TFT屏，這些參數(shù)要根據(jù)具體的LCD屏進(jìn)行設(shè)置
staticstructs3c2410fb_display smdk2440_lcd_cfg __initdata={

//這個(gè)地方的設(shè)置是配置LCD寄存器5，這些宏定義在regs-lcd.h中，計(jì)算后二進(jìn)制為：111111111111，然后對(duì)照數(shù)據(jù)手冊(cè)上LCDCON5的各位來看，注意是從右邊開始
.lcdcon5=S3C2410_LCDCON5_FRM565|
S3C2410_LCDCON5_INVVLINE|
S3C2410_LCDCON5_INVVFRAME|
S3C2410_LCDCON5_PWREN|
S3C2410_LCDCON5_HWSWP,

.type=S3C2410_LCDCON1_TFT,//TFT類型


.width=240,//屏幕寬度
.height=320,//屏幕高度

//以下一些參數(shù)在上面的時(shí)序圖分析中講到過,各參數(shù)的值請(qǐng)跟據(jù)具體的LCD屏數(shù)據(jù)手冊(cè)結(jié)合上面時(shí)序分析來設(shè)定
.pixclock=100000,//像素時(shí)鐘
.xres=240,//水平可見的有效像素
.yres=320,//垂直可見的有效像素
.bpp=16,//色位模式
.left_margin=19,//行切換，從同步到繪圖之間的延遲
.right_margin=36,//行切換，從繪圖到同步之間的延遲
.hsync_len=5,//水平同步的長(zhǎng)度
.upper_margin=1,//幀切換，從同步到繪圖之間的延遲
.lower_margin=5,//幀切換，從繪圖到同步之間的延遲
.vsync_len=1,//垂直同步的長(zhǎng)度
};

staticstructs3c2410fb_mach_info smdk2440_fb_info __initdata={
.displays=&smdk2440_lcd_cfg,//應(yīng)用上面定義的配置信息
.num_displays=1,
.default_display=0,

.gpccon=0xaaaa555a,//將GPC0、GPC1配置成LEND和VCLK，將GPC8-15配置成VD0-7,其他配置成普通輸出IO口
.gpccon_mask=0xffffffff,
.gpcup=0x0000ffff,//禁止GPIOC的上拉功能
.gpcup_mask=0xffffffff,
.gpdcon=0xaaaaaaaa,//將GPD0-15配置成VD8-23
.gpdcon_mask=0xffffffff,
.gpdup=0x0000ffff,//禁止GPIOD的上拉功能
.gpdup_mask=0xffffffff,

.lpcsel=0x0,//這個(gè)是三星TFT屏的參數(shù)，這里不用
};

//S3C2440初始化函數(shù)
staticvoid__init smdk2440_machine_init(void)
{

//調(diào)用該函數(shù)將上面定義的LCD硬件信息保存到平臺(tái)數(shù)據(jù)中
s3c24xx_fb_set_platdata(&smdk2440_fb_info);

s3c_i2c0_set_platdata(NULL);

platform_add_devices(smdk2440_devices,ARRAY_SIZE(smdk2440_devices));
smdk_machine_init();
}

void__init s3c24xx_fb_set_platdata(structs3c2410fb_mach_info*pd)
{
structs3c2410fb_mach_info*npd;

npd=kmalloc(sizeof(*npd),GFP_KERNEL);
if(npd){
memcpy(npd,pd,sizeof(*npd));

//這里就是將內(nèi)核中定義的s3c2410fb_mach_info結(jié)構(gòu)體數(shù)據(jù)保存到LCD平臺(tái)數(shù)據(jù)中，所以在寫驅(qū)動(dòng)的時(shí)候就可以直接在平臺(tái)數(shù)據(jù)中獲取s3c2410fb_mach_info結(jié)構(gòu)體的數(shù)據(jù)(即LCD各種參數(shù)信息)進(jìn)行操作
s3c_device_lcd.dev.platform_data=npd;
}else{
printk(KERN_ERR"no memory for LCD platform datan");
}
}