本代码来自于韦东山老师嵌入式二期驱动视频所讲解,仅供学习参考。如有侵权等行为,可当即撤销本文章。更多信息请关注www.100ask.com!!!
s3c2440_V3_4.3 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>
-
- static int s3c_lcdfb_setcolreg(unsigned int regno, unsigned int red,
- unsigned int green, unsigned int blue,
- unsigned int transp, struct fb_info *info);
-
-
- struct lcd_regs {
- 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 reserved[9];
- unsigned long dithmode;
- unsigned long tpal;
- unsigned long lcdintpnd;
- unsigned long lcdsrcpnd;
- unsigned long lcdintmsk;
- unsigned long lpcsel;
- };
-
- static struct fb_ops s3c_lcdfb_ops = {
- .owner = THIS_MODULE,
- .fb_setcolreg = s3c_lcdfb_setcolreg,
- .fb_fillrect = cfb_fillrect,
- .fb_copyarea = cfb_copyarea,
- .fb_imageblit = cfb_imageblit,
- };
-
-
- static struct fb_info *s3c_lcd;
- 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 volatile struct lcd_regs* lcd_regs;
- static u32 pseudo_palette[16];
-
-
- /* from pxafb.c */
- 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 s3c_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 int lcd_init(void)
- {
- /* 1. 分配一个fb_info */
- s3c_lcd = framebuffer_alloc(0, NULL);
-
- /* 2. 设置 */
- /* 2.1 设置固定的参数 */
- 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; /* TFT */
- s3c_lcd->fix.line_length = 480*2;
-
- /* 2.2 设置可变的参数 */
- 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;
-
- /* RGB:565 */
- s3c_lcd->var.red.offset = 11;
- s3c_lcd->var.red.length = 5;
-
- s3c_lcd->var.green.offset = 5;
- s3c_lcd->var.green.length = 6;
-
- s3c_lcd->var.blue.offset = 0;
- s3c_lcd->var.blue.length = 5;
-
- s3c_lcd->var.activate = FB_ACTIVATE_NOW;
-
-
- /* 2.3 设置操作函数 */
- s3c_lcd->fbops = &s3c_lcdfb_ops;
-
- /* 2.4 其他的设置 */
- s3c_lcd->pseudo_palette = pseudo_palette;
- //s3c_lcd->screen_base = ; /* 显存的虚拟地址 */
- s3c_lcd->screen_size = 480*272*16/8;
-
- /* 3. 硬件相关的操作 */
- /* 3.1 配置GPIO用于LCD */
- gpbcon = ioremap(0x56000010, 8);
- gpbdat = gpbcon+1;
- gpccon = ioremap(0x56000020, 4);
- gpdcon = ioremap(0x56000030, 4);
- gpgcon = ioremap(0x56000060, 4);
-
- *gpccon = 0xaaaaaaaa; /* GPIO管脚用于VD[7:0],LCDVF[2:0],VM,VFRAME,VLINE,VCLK,LEND */
- *gpdcon = 0xaaaaaaaa; /* GPIO管脚用于VD[23:8] */
-
- *gpbcon &= ~(3); /* GPB0设置为输出引脚 */
- *gpbcon |= 1;
- *gpbdat &= ~1; /* 输出低电平 */
-
- *gpgcon |= (3<<8); /* GPG4用作LCD_PWREN */
-
- /* 3.2 根据LCD手册设置LCD控制器, 比如VCLK的频率等 */
- lcd_regs = ioremap(0x4D000000, sizeof(struct lcd_regs));
-
- /* bit[17:8]: VCLK = HCLK / [(CLKVAL+1) x 2], LCD手册P14
- * 10MHz(100ns) = 100MHz / [(CLKVAL+1) x 2]
- * CLKVAL = 4
- * bit[6:5]: 0b11, TFT LCD
- * bit[4:1]: 0b1100, 16 bpp for TFT
- * bit[0] : 0 = Disable the video output and the LCD control signal.
- */
- lcd_regs->lcdcon1 = (4<<8) | (3<<5) | (0x0c<<1);
-
- #if 1
- /* 垂直方向的时间参数
- * bit[31:24]: VBPD, VSYNC之后再过多长时间才能发出第1行数据
- * LCD手册 T0-T2-T1=4
- * VBPD=3
- * bit[23:14]: 多少行, 320, 所以LINEVAL=320-1=319
- * bit[13:6] : VFPD, 发出最后一行数据之后,再过多长时间才发出VSYNC
- * LCD手册T2-T5=322-320=2, 所以VFPD=2-1=1
- * bit[5:0] : VSPW, VSYNC信号的脉冲宽度, LCD手册T1=1, 所以VSPW=1-1=0
- */
- lcd_regs->lcdcon2 = (1<<24) | (271<<14) | (1<<6) | (9);
-
-
- /* 水平方向的时间参数
- * bit[25:19]: HBPD, VSYNC之后再过多长时间才能发出第1行数据
- * LCD手册 T6-T7-T8=17
- * HBPD=16
- * bit[18:8]: 多少列, 240, 所以HOZVAL=240-1=239
- * bit[7:0] : HFPD, 发出最后一行里最后一个象素数据之后,再过多长时间才发出HSYNC
- * LCD手册T8-T11=251-240=11, 所以HFPD=11-1=10
- */
- lcd_regs->lcdcon3 = (1<<19) | (479<<8) | (1);
-
- /* 水平方向的同步信号
- * bit[7:0] : HSPW, HSYNC信号的脉冲宽度, LCD手册T7=5, 所以HSPW=5-1=4
- */
- lcd_regs->lcdcon4 = 40;
-
- #else
- lcd_regs->lcdcon2 = S3C2410_LCDCON2_VBPD(5) | \
- S3C2410_LCDCON2_LINEVAL(319) | \
- S3C2410_LCDCON2_VFPD(3) | \
- S3C2410_LCDCON2_VSPW(1);
-
- lcd_regs->lcdcon3 = S3C2410_LCDCON3_HBPD(10) | \
- S3C2410_LCDCON3_HOZVAL(239) | \
- S3C2410_LCDCON3_HFPD(1);
-
- lcd_regs->lcdcon4 = S3C2410_LCDCON4_MVAL(13) | \
- S3C2410_LCDCON4_HSPW(0);
-
- #endif
- /* 信号的极性
- * bit[11]: 1=565 format
- * bit[10]: 0 = The video data is fetched at VCLK falling edge
- * 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_regs->lcdcon5 = (1<<11) | (0<<10) | (1<<9) | (1<<8) | (1<<0);
-
- /* 3.3 分配显存(framebuffer), 并把地址告诉LCD控制器 */
- s3c_lcd->screen_base = dma_alloc_writecombine(NULL, s3c_lcd->fix.smem_len, &s3c_lcd->fix.smem_start, GFP_KERNEL);
-
- lcd_regs->lcdsaddr1 = (s3c_lcd->fix.smem_start >> 1) & ~(3<<30);
- lcd_regs->lcdsaddr2 = ((s3c_lcd->fix.smem_start + s3c_lcd->fix.smem_len) >> 1) & 0x1fffff;
- lcd_regs->lcdsaddr3 = (480*16/16); /* 一行的长度(单位: 2字节) */
-
- //s3c_lcd->fix.smem_start = xxx; /* 显存的物理地址 */
- /* 启动LCD */
- lcd_regs->lcdcon1 |= (1<<0); /* 使能LCD控制器 */
- lcd_regs->lcdcon5 |= (1<<3); /* 使能LCD本身 */
- *gpbdat |= 1; /* 输出高电平, 使能背光 */
-
- /* 4. 注册 */
- register_framebuffer(s3c_lcd);
-
- return 0;
- }
-
- static void lcd_exit(void)
- {
- unregister_framebuffer(s3c_lcd);
- lcd_regs->lcdcon1 &= ~(1<<0); /* 关闭LCD本身 */
- *gpbdat &= ~1; /* 关闭背光 */
- dma_free_writecombine(NULL, s3c_lcd->fix.smem_len, s3c_lcd->screen_base, s3c_lcd->fix.smem_start);
- iounmap(lcd_regs);
- iounmap(gpbcon);
- iounmap(gpccon);
- iounmap(gpdcon);
- iounmap(gpgcon);
- framebuffer_release(s3c_lcd);
- }
-
- module_init(lcd_init);
- module_exit(lcd_exit);
-
- MODULE_LICENSE("GPL");
-
-
- 1. cd /work/system/linux-2.6.22.6,执行 make menuconfig命令.
- 2. 选择 -> Device Drivers
- 选择 -> Graphics support
- <M> S3C2410 LCD framebuffer support
- /*上面“<*> S3C2410 LCD framebuffer support”是之前自带的驱动程序,这里去掉后以<M>模块方式编译进内核.*/
- 3. 执行 config_ok .config
- 执行 make menuconfig (生成uImage文件)
- 执行 make modules (cfbcopyarea.ko,cfbfillrect.ko,cfbimgblt.ko)
- 4. cp arch/arm/boot/uImage /work/nfs_root/uImage_nolcd
- cp drivers/video cfb*.ko /work/nfs_root/first_fs
- 5. cd /work/driver_and _test/4th_4.3
- make(生成lcd.ko)
- cp lcd.ko /work/nfs_root/first_fs
- 6. insmod cfbcopyarea.ko
- insmod cfbfillrect.ko
- insmod cfbimgblt.ko
- insmod lcd.c