韦东山视频之LCD驱动(Mini2440 X35)

测试平台： Mini2440  Sonic X35 Lcd  Linux-2.6.29  u-boot 2008.10

实验思考：

说起这块屏幕，可真是费劲，LCD原理图跟别人的好多不一样，时序图也有很大的差别，LCD上vline 和vframe根本没有，只能通过pci和mck两个时钟进行设置；

还一个就是：不知道是uboot的原因还是友善官网提供的原理图有错 ，vden必须反转才能正常！！

 源代码：

#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 <linux/types.h>#include <asm/mach/map.h>#include <mach/regs-lcd.h>#include <mach/regs-gpio.h>#include <mach/fb.h>struct lcd_regs{unsigned long   lcdcon1;    unsigned longlcdcon2;unsigned longlcdcon3;unsigned longlcdcon4;unsigned longlcdcon5;unsigned longlcdsaddr1;unsigned longlcdsaddr2;unsigned longlcdsaddr3;unsigned longredlut;unsigned longgreenlut;unsigned longbluelut; unsigned longreserved[9];unsigned longdithmode;unsigned longtpal;unsigned longlcdintpnd;unsigned longlcdsrcpnd;unsigned longlcdintmsk;unsigned longlpcsel;};static volatile struct lcd_regs *lcd_regs_base;static struct fb_info *fb_x35;static volatile unsigned long *gpbcon;static volatile unsigned long *gpbdat;static volatile unsigned long *gpccon;static volatile unsigned long *gpdcon;static volatile unsigned long *gpgcon;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;}//设置颜色static int x35_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;val  = chan_to_field(red,&info->var.red);val |= chan_to_field(green, &info->var.green);val |= chan_to_field(blue,&info->var.blue);pseudo_palette[regno] = val;return 0;}static struct fb_ops mini_fb_ops = {.owner = THIS_MODULE,.fb_setcolreg = x35_setcolreg,.fb_fillrect  = cfb_fillrect,.fb_copyarea  = cfb_copyarea,.fb_imageblit   = cfb_imageblit,};static int lcd_init(void){//1)分配一个fb_infofb_x35 = framebuffer_alloc(0, NULL);//2)填充fb_info结构// 1 设置固定参数// 2 设置可变参数// 3 设置操作函数// 4 其他的设置strcpy(fb_x35->fix.id, "mylcd");fb_x35->fix.smem_len = 240 * 320 * 32 / 8;  // frambuffer的大小fb_x35->fix.type = FB_TYPE_PACKED_PIXELS;//扫描方式，以像素点扫描 非隔行扫描fb_x35->fix.visual = FB_VISUAL_TRUECOLOR; //色阶 真彩色fb_x35->fix.line_length = 240 * 4;fb_x35->var.xres = 240;fb_x35->var.yres = 320;fb_x35->var.xres_virtual = 240;fb_x35->var.yres_virtual = 320;fb_x35->var.bits_per_pixel = 32;  //每个像素点占有的字节数//颜色放置的方式，这里是真彩色为 8:8:8,每种颜色占用8位fb_x35->var.red.offset = 16;fb_x35->var.red.length = 8;fb_x35->var.blue.offset = 8;fb_x35->var.blue.length = 8;fb_x35->var.green.offset = 0;fb_x35->var.green.length = 8;fb_x35->var.activate = FB_ACTIVATE_NOW; //设置颜色立即生效//设置操作函数fb_x35->fbops = &mini_fb_ops;fb_x35->pseudo_palette = pseudo_palette; //调色板fb_x35->screen_size = 240 * 320 * 32 / 8;  //屏幕尺寸的大小//3)设置硬件，驱动lcd// 1 设置lcd引脚可用// 2 设置lcd控制器寄存器// 3 设置其他的gpbcon = ioremap(0x56000010, 8);gpbdat = gpbcon+1;gpccon = ioremap(0x5600020, 4);gpdcon = ioremap(0x5600030, 4);gpgcon = ioremap(0x5600060, 4);*gpccon = 0xaaaaaaaa;*gpdcon = 0xaaaaaaaa;*gpgcon |= (0x3 << (4 * 2));  //lcd_pwren lcd电源引脚lcd_regs_base = ioremap(0x4d000000, sizeof(struct lcd_regs));lcd_regs_base->lcdcon1 = (9 << 8) | (3 << 5) | (0xd << 1);lcd_regs_base->lcdcon2 = (8 << 24) | (319 << 14) | (4 << 6) | (9 << 0);lcd_regs_base->lcdcon3 = (15 << 19) | (239 << 8) | (16 << 0) ;lcd_regs_base->lcdcon4 = 5;lcd_regs_base->lcdcon5 = (0 << 12) | (0 << 10) | (1<<6) | (0 << 1) | (0 << 0) ;//vsync swap set error//分配显存，将显存地址告诉framebufferfb_x35->screen_base = dma_alloc_writecombine(NULL, fb_x35->fix.smem_len, &(fb_x35->fix.smem_start), GFP_KERNEL);//fb_x35->fix.smem_start = xxx;  /* 显存的物理地址 */lcd_regs_base->lcdsaddr1 = (fb_x35->fix.smem_start >> 1) & (~(3 << 30)); //[31~0]=0b00xx xxxx ... 30误写成20lcd_regs_base->lcdsaddr2 = ((fb_x35->fix.smem_start + fb_x35->fix.smem_len) >> 1) & 0x1fffff;lcd_regs_base->lcdsaddr3 = (0 << 11) | ((240 * 32 / 16) << 0); //行的长度有错//启动lcdlcd_regs_base->lcdcon1 |= (1 << 0);lcd_regs_base->lcdcon5 |= (1 << 3);/* MINI2440的背光电路也是通过LCD_PWREN来控制的, 不需要单独的背光引脚 *///4)注册framebufferregister_framebuffer(fb_x35);return 0;}static void lcd_exit(void){//注销framebuffer结构//释放分配的frambuffer显存//关闭lcd控制器以及电源//取消映射地址//释放framebuffer结构unregister_framebuffer(fb_x35);lcd_regs_base->lcdcon1 &= ~(1 << 0);lcd_regs_base->lcdcon5 &= ~(1 << 3);dma_free_writecombine(NULL, fb_x35->fix.smem_len, fb_x35->screen_base, fb_x35->fix.smem_start);iounmap(lcd_regs_base);iounmap(gpccon);iounmap(gpdcon);iounmap(gpgcon);framebuffer_release(fb_x35);}module_init(lcd_init);module_exit(lcd_exit);MODULE_LICENSE("GPL");MODULE_AUTHOR("LCL");

如何测试：

1. make menuconfig去掉原来的驱动程序
-> Device Drivers
  -> Graphics support
<M> S3C2410 LCD framebuffer support

2. make uImage
   make modules 

3. 使用新的uImage启动开发板:

4. 先将之前module下编译出来的几个文件拷到开发板上cfbcopyarea.ko cfbfillrect.ko cfbimgblt.ko(/drivers/video/*)

5.

insmod cfbcopyarea.ko
insmod cfbfillrect.ko
insmod cfbimgblt.ko
insmod lcd.ko

6.

echo hello > /dev/tty1  // 可以在LCD上看见hello
cat lcd.ko > /dev/fb0   // 花屏

当然也可以测试其他的，这里不进行描述。

注意：里面的图像调整其实还不是最关键的，关键是vden不翻转 就没有图像，我调试过好多次，幸亏论坛网友热心帮助，才点亮lcd。