框架入口源文件： lcd.c
（可根据入口源文件，再按着框架到内核走一遍）
内核版本：linux_2.6.22.6 硬件平台：JZ2440
驱动框架：
以下是驱动代码：
LCD.c
#include <linux/module.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/slab.h> #include <linux/delay.h> #include <linux/fb.h> #include <linux/init.h> #include <linux/dma-mapping.h> #include <linux/interrupt.h> #include <linux/workqueue.h> #include <linux/wait.h> #include <linux/platform_device.h> #include <linux/clk.h> #include <asm/io.h> #include <asm/uaccess.h> #include <asm/div64.h> #include <asm/mach/map.h> #include <asm/arch/regs-lcd.h> #include <asm/arch/regs-gpio.h> #include <asm/arch/fb.h> //定义一个 fd_info 结构体 static struct fb_info *s3c_lcd ; //IO寄存器 static volatile unsigned long *gpccon; static volatile unsigned long *gpdcon; static volatile unsigned long *gpbdat; static volatile unsigned long *gpbcon; static volatile unsigned long *gpgcon; //LCD控制寄存器 static struct lcd_con { unsigned long LCDCON1; unsigned long LCDCON2; unsigned long LCDCON3; unsigned long LCDCON4; unsigned long LCDCON5; unsigned long LCDSADDR1; unsigned long LCDSADDR2; unsigned long LCDSADDR3; unsigned long REDLUT; unsigned long GREENLUT; unsigned long BLUELUT; unsigned long RESERVE[9]; //guess why unsigned long DITHMODE; unsigned long TPAL; unsigned long LCDINTPND; unsigned long LCDSRCPND; unsigned long LCDINTMSK; unsigned long LPCSEL; }; static volatile struct lcd_con *lcd_con; static int lcd_pseudo_palette(unsigned int regno, unsigned int red, unsigned int green, unsigned int blue, unsigned int transp, struct fb_info *info); //定义一个 fd_ops 结构体 static struct fb_ops lcd_fb_fops = { .owner = THIS_MODULE, .fb_setcolreg = lcd_pseudo_palette, .fb_fillrect = cfb_fillrect, .fb_copyarea = cfb_copyarea, .fb_imageblit = cfb_imageblit, }; //设置调色板 static u32 pseudo_palette[16]; 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 lcd_pseudo_palette(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 int lcd_init(void) { //申请一个 fd_info 结构体 s3c_lcd = framebuffer_alloc(0,NULL); //初始化 fd_info 结构体 /*设置固定参数*/ strcpy(s3c_lcd->fix.id ," mylcd"); s3c_lcd->fix.smem_len = 480*272*16/8; s3c_lcd->fix.type = FB_TYPE_PACKED_PIXELS; s3c_lcd->fix.visual = FB_VISUAL_TRUECOLOR;//lcd 类型 s3c_lcd->fix.line_length = 480*2; /*设置可变参数*/ s3c_lcd->var.xres =480; s3c_lcd->var.yres =272; s3c_lcd->var.xres_virtual =480; s3c_lcd->var.yres_virtual =272; s3c_lcd->var.bits_per_pixel =16; s3c_lcd->var.green.length =6; s3c_lcd->var.green.offset =5; s3c_lcd->var.red.length =5; s3c_lcd->var.red.offset =11; s3c_lcd->var.blue.length =5; s3c_lcd->var.blue.offset =0; s3c_lcd->var.activate = FB_ACTIVATE_NOW; /*设置操作函数*/ s3c_lcd->fbops =&lcd_fb_fops; /*调色盘*/ s3c_lcd->pseudo_palette = lcd_pseudo_palette; s3c_lcd->screen_size =480*272*2; //设置 LCD控制器寄存器 IO寄存器 // 1.VD IO gpccon = ioremap(0x56000020,4); gpdcon = ioremap(0x56000030,4); *gpccon = 0xaaaaaaaa; *gpdcon = 0xaaaaaaaa; // 2. KEYBOARD LCD_PWENB gpbcon = ioremap(0x56000010,4); gpbdat = gpbcon +1; gpgcon = ioremap(0x56000060,4); *gpbcon &= ~3; // gpb0 KEYBOARD 背光 *gpbcon |= 1; *gpbdat &= ~1; *gpgcon |= (3<<8); //gpg4 LCD_PWENB 电源 // 3. 控制寄存器 lcd_con = ioremap(0x4d000000, sizeof(struct lcd_con)); /* lcdcon1 * bit[17:8] VCLK = HCLK / [(CLKVAL + 1) × 2] VCLK=10000KHZ HCLK=100000KHZ CLKVAL=4 * bit[6:5] 0b11 tft_lcd 面板 * bit[4:1] 0b1100 16bpp * bit[0] 0 禁止vd 1 使能vd */ lcd_con->LCDCON1 = (4<<8)|(3<<5)|(12<<1)|(0<<0); /* lcdcon2 垂直方向时间参数 * bit[31:24] VBPD 垂直同步周期后的的无效行数 lcd芯片手册p15 T0-T2-T1= 327 - 322 - 1 = 4 3 * bit[23:14] LINEVAL LCD 面板的垂直尺寸 320-1 = 319 * bit[13:6] VFPD 垂直同步周期前的的无效行数 t2 -t5 = 322 - 320 - 1 = 1 * bit[5:0] VSPW VSYNC 脉冲的高电平宽度 T1 -1 = 0 */ lcd_con->LCDCON2 = (1<<24) | (271<<14) | (1<<6) | (9); /* lcdcon3 水平方向时间参数 * bit[25:19] tft_lcd HSYNC 的下降沿与有效数据的开始之间的 VCLK 周期数 T6 -T7 -T8 = 17 16 * bit[18:8] LCD 面板的水平尺寸 240-1=239 * bit[7:0] 有效数据的结束与 HSYNC 的上升沿之间的 VCLK 周期数 11 - 1 = 10 */ lcd_con->LCDCON3 = (1<<19) | (479<<8) | (1); /* lcdcon4 水平方向同步信号 * bit[15:8] * bit[7:0] 算 VCLK 的数水平同步脉冲宽度决定 HSYNC 脉冲的高电平宽度 5-1=4 */ lcd_con->LCDCON4 = 40; /* lcdcon5 * bit[11] 1 16bpp 5:6:5 格式 * bit[10] 0 = VCLK 下降沿取视频数据 * bit[9] 1 = HSYNC信号要反转,即低电平有效 * bit[8] 1 = VSYNC信号要反转,即低电平有效 * bit[6] 0 = VDEN不用反转 * bit[3] 0 = PWREN输出0 * bit[1] 0 = BSWP * bit[0] 1 = HWSWP 2440手册P413 */ lcd_con->LCDCON5 = (1<<11)|(0<<10)|(1<<9)|(1<<8)|(0<<6)|(0<<3)|(0<<1)|(1<<0); // 4. 分配显存 s3c_lcd->screen_base =dma_alloc_writecombine(NULL,s3c_lcd->fix.smem_len,&s3c_lcd->fix.smem_start,GFP_KERNEL); /* * bit[29:21] 帧内存起始地址 * bit[20:0] 视口缓冲区起始地址 */ lcd_con->LCDSADDR1 = (s3c_lcd->fix.smem_start>>1)& ~(3<<30); /* * bit[20:0] 视口缓冲区结束地址 */ lcd_con->LCDSADDR2 = ((s3c_lcd->fix.smem_start + s3c_lcd->fix.smem_len)>>1 ) & 0x1fffff; /* * bit[21:11] 一行最后一个数据与下一行最开始数据的 差值的一半 * bit[10:0] 视口的宽度 */ lcd_con->LCDSADDR3 =480*1; //启动LCD lcd_con->LCDCON1 |= (1<<0); /* 使能LCD控制器 */ lcd_con->LCDCON5 |= (1<<3); /* 使能LCD本身 */ *gpbdat |= 1; /* 输出高电平, 使能背光 */ //注册 fd_info 结构体 register_framebuffer(s3c_lcd); return 0; } static void lcd_exit(void) { //去掉注册的 fd_info 结构体 unregister_framebuffer(s3c_lcd); //释放 fd_info 结构体空间 framebuffer_release(s3c_lcd); //取消映射 iounmap(lcd_con); iounmap(gpbcon); iounmap(gpccon); iounmap(gpdcon); iounmap(gpgcon); iounmap(gpbdat); //释放帧内存 dma_free_writecombine(NULL, s3c_lcd->fix.smem_len, s3c_lcd->screen_base, s3c_lcd->fix.smem_start); //关闭LCD lcd_con->LCDCON1 &= ~(1<<0); /* 关闭LCD本身 */ *gpbdat &= ~1; /* 关闭背光 */ } module_init(lcd_init); module_exit(lcd_exit); MODULE_LICENSE("GPL");
以下是编译驱动的Makefile：
KERN_DIR = /work/systems/kernel/linux-2/linux-2.6.22.6 all: make -C $(KERN_DIR) M=`pwd` modules clean: make -C $(KERN_DIR) M=`pwd` modules clean rm -rf modules.order obj-m += lcd.o