LCD驱动程序架构和分析

一、LCD驱动程序架构

1.裸机驱动代码分析

①LCD初始化：控制器初始化，端口初始化，指明帧缓冲

②LCD图形显示：将图形数据写入帧缓冲

1. void lcd_init()
2. {
3. lcd_port_init();     //初始化gpdcon和gpccon初始化
4. lcd_control_init();   //时序初始化和帧缓冲初始化
5. //打开LCD电源
6. GPGCON |= 0b11<<8;
7. LCDCON5 |= (1<<3);
8. LCDCON1 |= 1;
9. }

2.帧缓冲体验

帧缓冲：内存中的一段区域，通过对内存的修改。LCD控制器从内存中获取数据，自动的控制LCD的显示。

1. # cat tq2440.bin > /dev/fb0

将图片显示到lcd。



3.帧缓冲架构

/dev/fb0就是帧缓冲，字符设备

fbmem_init():

1. static int __init
2. fbmem_init(void)
3. {
4. proc_create("fb", 0, NULL, &fb_proc_fops);
5. if (register_chrdev(FB_MAJOR,"fb",&fb_fops))                                                    //注册设备文件，注册帧缓冲，fp_fops是操作函数集
6. printk("unable to get major %d for fb devs\n", FB_MAJOR);
7. fb_class = class_create(THIS_MODULE, "graphics");
8. if (IS_ERR(fb_class)) {
9. printk(KERN_WARNING "Unable to create fb class; errno = %ld\n", PTR_ERR(fb_class));
10. fb_class = NULL;
11. }
12. return 0;
13. }

fb_ops:

1. static const struct file_operations fb_fops = {
2. .owner =    THIS_MODULE,
3. .read =        fb_read,                                        //写入
4. .write =    fb_write,
5. .unlocked_ioctl = fb_ioctl,
6. #ifdef CONFIG_COMPAT
7. .compat_ioctl = fb_compat_ioctl,
8. #endif
9. .mmap =        fb_mmap,
10. .open =        fb_open,
11. .release =    fb_release,
12. #ifdef HAVE_ARCH_FB_UNMAPPED_AREA
13. .get_unmapped_area = get_fb_unmapped_area,
14. #endif
15. #ifdef CONFIG_FB_DEFERRED_IO
16. .fsync =    fb_deferred_io_fsync,
17. #endif
18. };

fb_write:

1. static ssize_t
2. fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
3. {
4. unsigned long p = *ppos;
5. struct inode *inode = file->f_path.dentry->d_inode;
6. int fbidx = iminor(inode);
7. struct fb_info *info = registered_fb[fbidx];
8. u32 *buffer, *src;
9. u32 __iomem *dst;
10. int c, i, cnt = 0, err = 0;
11. unsigned long total_size;
12. if (!info || !info->screen_base)
13. return -ENODEV;
14. if (info->state != FBINFO_STATE_RUNNING)
15. return -EPERM;
16. if (info->fbops->fb_write)
17. return info->fbops->fb_write(info, buf, count, ppos);
18. total_size = info->screen_size;
19. if (total_size == 0)
20. total_size = info->fix.smem_len;
21. if (p > total_size)
22. return -EFBIG;
23. if (count > total_size) {
24. err = -EFBIG;
25. count = total_size;
26. }
27. if (count + p > total_size) {
28. .........各种info
29. }

info结构：

1. struct fb_info {
2. int node;
3. int flags;
4. struct mutex lock;                                //控制io操作锁
5. struct fb_var_screeninfo var;/*LCD可变参数*/
6. struct fb_fix_screeninfo fix;/*LCD固定参数*/
7. struct fb_monspecs monspecs; /*LCD显示器标准*/
8. struct work_struct queue; /*帧缓冲事件队列*/
9. struct fb_pixmap pixmap; /*图像硬件mapper*/
10. struct fb_pixmap sprite; /*光标硬件mapper*/
11. struct fb_cmap cmap; /*当前的颜色表*/
12. struct fb_videomode *mode; /*当前的显示模式*/
13. #ifdef CONFIG_FB_BACKLIGHT
14. struct backlight_device *bl_dev;/*对应的背光设备*/
15. struct mutex bl_curve_mutex;
16. u8 bl_curve[FB_BACKLIGHT_LEVELS];/*背光调整*/
17. #endif
18. #ifdef CONFIG_FB_DEFERRED_IO
19. struct delayed_work deferred_work;
20. struct fb_deferred_io *fbdefio;
21. #endif
22. struct fb_ops *fbops; /*对底层硬件操作的函数指针*/
23. struct device *device;
24. struct device *dev; /*fb设备*/
25. int class_flag;
26. #ifdef CONFIG_FB_TILEBLITTING
27. struct fb_tile_ops *tileops; /*图块Blitting*/
28. #endif
29. char __iomem *screen_base; /*虚拟基地址*/
30. unsigned long screen_size; /*LCD IO映射的虚拟内存大小*/
31. void *pseudo_palette; /*伪16色颜色表*/
32. #define FBINFO_STATE_RUNNING 0
33. #define FBINFO_STATE_SUSPENDED 1
34. u32 state; /*LCD的挂起或恢复状态*/
35. void *fbcon_par;
36. void *par;
37. };

主要是fb_var_screeninfo、fb_fix_screeninfo、fb_ops三个结构体：

struct fb_var_screeninfo:主要记录用户可以修改的控制器的参数。

1. struct fb_var_screeninfo {
2. __u32 xres;            /* visible resolution        */
3. __u32 yres;
4. __u32 xres_virtual;        /* virtual resolution        */
5. __u32 yres_virtual;
6. __u32 xoffset;            /* offset from virtual to visible */
7. __u32 yoffset;            /* resolution            */
8. __u32 bits_per_pixel;        /* guess what            */每个像素的位数即BPP
9. __u32 grayscale;        /* != 0 Graylevels instead of colors */
10. struct fb_bitfield red;        /* bitfield in fb mem if true color, */
11. struct fb_bitfield green;    /* else only length is significant */
12. struct fb_bitfield blue;
13. struct fb_bitfield transp;    /* transparency            */
14. __u32 nonstd;            /* != 0 Non standard pixel format */
15. __u32 activate;            /* see FB_ACTIVATE_*        */
16. __u32 height;            /* height of picture in mm */
17. __u32 width;            /* width of picture in mm */
18. __u32 accel_flags;        /* (OBSOLETE) see fb_info.flags */
19. /* Timing: All values in pixclocks, except pixclock (of course) */
20. __u32 pixclock;            /* pixel clock in ps (pico seconds) */
21. __u32 left_margin;        /* time from sync to picture    */
22. __u32 right_margin;        /* time from picture to sync    */
23. __u32 upper_margin;        /* time from sync to picture    */
24. __u32 lower_margin;
25. __u32 hsync_len;        /* length of horizontal sync    */
26. __u32 vsync_len;        /* length of vertical sync    */
27. __u32 sync;            /* see FB_SYNC_*        */
28. __u32 vmode;            /* see FB_VMODE_*        */
29. __u32 rotate;            /* angle we rotate counter clockwise */
30. __u32 reserved[5];        /* Reserved for future compatibility */
31. };

fb_fix_screeninfo:主要记录用户不可以修改的控制器的参数

1. struct fb_fix_screeninfo {
2. char id[16];            /* identification string eg "TT Builtin" */
3. unsigned long smem_start;    /* Start of frame buffer mem */
4. /* (physical address) */
5. __u32 smem_len;            /* Length of frame buffer mem */
6. __u32 type;            /* see FB_TYPE_*        */
7. __u32 type_aux;            /* Interleave for interleaved Planes */
8. __u32 visual;            /* see FB_VISUAL_*        */
9. __u16 xpanstep;            /* zero if no hardware panning */
10. __u16 ypanstep;            /* zero if no hardware panning */
11. __u16 ywrapstep;        /* zero if no hardware ywrap */
12. __u32 line_length;        /* length of a line in bytes */
13. unsigned long mmio_start;    /* Start of Memory Mapped I/O */
14. /* (physical address) */
15. __u32 mmio_len;            /* Length of Memory Mapped I/O */
16. __u32 accel;            /* Indicate to driver which    */
17. /* specific chip/card we have    */
18. __u16 reserved[3];        /* Reserved for future compatibility */
19. };

fb_ops:底层硬件操作的函数指针

1. struct fb_ops {
2. /* open/release and usage marking */
3. struct module *owner;
4. int (*fb_open)(struct fb_info *info, int user);
5. int (*fb_release)(struct fb_info *info, int user);
6. /* For framebuffers with strange non linear layouts or that do not
7. * work with normal memory mapped access
8. */
9. ssize_t (*fb_read)(struct fb_info *info, char __user *buf,
10. size_t count, loff_t *ppos);
11. ssize_t (*fb_write)(struct fb_info *info, const char __user *buf,
12. size_t count, loff_t *ppos);
13. /* checks var and eventually tweaks it to something supported,
14. * DO NOT MODIFY PAR */
15. int (*fb_check_var)(struct fb_var_screeninfo *var, struct fb_info *info);
16. /* set the video mode according to info->var */
17. int (*fb_set_par)(struct fb_info *info);
18. /* set color register */
19. int (*fb_setcolreg)(unsigned regno, unsigned red, unsigned green,
20. unsigned blue, unsigned transp, struct fb_info *info);
21. /* set color registers in batch */
22. int (*fb_setcmap)(struct fb_cmap *cmap, struct fb_info *info);
23. /* blank display */
24. int (*fb_blank)(int blank, struct fb_info *info);
25. /* pan display */
26. int (*fb_pan_display)(struct fb_var_screeninfo *var, struct fb_info *info);
27. /* Draws a rectangle */
28. void (*fb_fillrect) (struct fb_info *info, const struct fb_fillrect *rect);
29. /* Copy data from area to another */
30. void (*fb_copyarea) (struct fb_info *info, const struct fb_copyarea *region);
31. /* Draws a image to the display */
32. void (*fb_imageblit) (struct fb_info *info, const struct fb_image *image);
33. /* Draws cursor */
34. int (*fb_cursor) (struct fb_info *info, struct fb_cursor *cursor);
35. /* Rotates the display */
36. void (*fb_rotate)(struct fb_info *info, int angle);
37. /* wait for blit idle, optional */
38. int (*fb_sync)(struct fb_info *info);
39. /* perform fb specific ioctl (optional) */
40. int (*fb_ioctl)(struct fb_info *info, unsigned int cmd,
41. unsigned long arg);
42. /* Handle 32bit compat ioctl (optional) */
43. int (*fb_compat_ioctl)(struct fb_info *info, unsigned cmd,
44. unsigned long arg);
45. /* perform fb specific mmap */
46. int (*fb_mmap)(struct fb_info *info, struct vm_area_struct *vma);
47. /* save current hardware state */
48. void (*fb_save_state)(struct fb_info *info);
49. /* restore saved state */
50. void (*fb_restore_state)(struct fb_info *info);
51. /* get capability given var */
52. void (*fb_get_caps)(struct fb_info *info, struct fb_blit_caps *caps,
53. struct fb_var_screeninfo *var);
54. };

http://www.cnblogs.com/lishixian/articles/2999923.html



二、LCD驱动程序分析

s3c2410fb_init:

1. int __init s3c2410fb_init(void)
2. {
3. int ret = platform_driver_register(&s3c2410fb_driver);                        //注册平台驱动设备
4. if (ret == 0)
5. ret = platform_driver_register(&s3c2412fb_driver);;
6. return ret;
7. }

s3c2410fb_driver:

1. static struct platform_driver s3c2410fb_driver = {
2. .probe        = s3c2410fb_probe,                                                //probe函数，里面调用了s3c24xxfb_probe
3. .remove        = s3c2410fb_remove,
4. .suspend    = s3c2410fb_suspend,
5. .resume        = s3c2410fb_resume,
6. .driver        = {
7. .name    = "s3c2410-lcd",
8. .owner    = THIS_MODULE,
9. },
10. };

s3c24xxfb_probe:

1. static int __init s3c24xxfb_probe(struct platform_device *pdev,
2. enum s3c_drv_type drv_type)
3. {
4. struct s3c2410fb_info *info;
5. struct s3c2410fb_display *display;
6. struct fb_info *fbinfo;
7. struct s3c2410fb_mach_info *mach_info;
8. struct resource *res;
9. int ret;
10. int irq;
11. int i;
12. int size;
13. u32 lcdcon1;
14. mach_info = pdev->dev.platform_data;
15. if (mach_info == NULL) {
16. dev_err(&pdev->dev,
17. "no platform data for lcd, cannot attach\n");
18. return -EINVAL;
19. }
20. if (mach_info->default_display >= mach_info->num_displays) {
21. dev_err(&pdev->dev, "default is %d but only %d displays\n",
22. mach_info->default_display, mach_info->num_displays);
23. return -EINVAL;
24. }
25. display = mach_info->displays + mach_info->default_display;
26. irq = platform_get_irq(pdev, 0);                                                       //获取中断号
27. if (irq < 0) {
28. dev_err(&pdev->dev, "no irq for device\n");
29. return -ENOENT;
30. }
31. fbinfo = framebuffer_alloc(sizeof(struct s3c2410fb_info), &pdev->dev);                 //分配fb_info结构
32. if (!fbinfo)
33. return -ENOMEM;
34. platform_set_drvdata(pdev, fbinfo);
35. info = fbinfo->par;
36. info->dev = &pdev->dev;
37. info->drv_type = drv_type;
38. res = platform_get_resource(pdev, IORESOURCE_MEM, 0);                                   //获取寄存器地址
39. if (res == NULL) {
40. dev_err(&pdev->dev, "failed to get memory registers\n");
41. ret = -ENXIO;
42. goto dealloc_fb;
43. }
44. size = (res->end - res->start) + 1;
45. info->mem = request_mem_region(res->start, size, pdev->name);
46. if (info->mem == NULL) {
47. dev_err(&pdev->dev, "failed to get memory region\n");
48. ret = -ENOENT;
49. goto dealloc_fb;
50. }
51. info->io = ioremap(res->start, size);                                                 //转化成虚拟地址
52. if (info->io == NULL) {
53. dev_err(&pdev->dev, "ioremap() of registers failed\n");
54. ret = -ENXIO;
55. goto release_mem;
56. }
57. info->irq_base = info->io + ((drv_type == DRV_S3C2412) ? S3C2412_LCDINTBASE : S3C2410_LCDINTBASE);
58. dprintk("devinit\n");
59. strcpy(fbinfo->fix.id, driver_name);
60. /* Stop the video */                                                                   //初始化fbinfo结构
61. lcdcon1 = readl(info->io + S3C2410_LCDCON1);
62. writel(lcdcon1 & ~S3C2410_LCDCON1_ENVID, info->io + S3C2410_LCDCON1);
63. fbinfo->fix.type     = FB_TYPE_PACKED_PIXELS;
64. fbinfo->fix.type_aux     = 0;
65. fbinfo->fix.xpanstep     = 0;
66. fbinfo->fix.ypanstep     = 0;
67. fbinfo->fix.ywrapstep     = 0;
68. fbinfo->fix.accel     = FB_ACCEL_NONE;
69. fbinfo->var.nonstd     = 0;
70. fbinfo->var.activate     = FB_ACTIVATE_NOW;
71. fbinfo->var.accel_flags = 0;
72. fbinfo->var.vmode     = FB_VMODE_NONINTERLACED;
73. fbinfo->fbops         = &s3c2410fb_ops;
74. fbinfo->flags         = FBINFO_FLAG_DEFAULT;
75. fbinfo->pseudo_palette = &info->pseudo_pal;
76. for (i = 0; i < 256; i++)
77. info->palette_buffer[i] = PALETTE_BUFF_CLEAR;
78. ret = request_irq(irq, s3c2410fb_irq, IRQF_DISABLED, pdev->name, info);                      //注册中断函数
79. if (ret) {
80. dev_err(&pdev->dev, "cannot get irq %d - err %d\n", irq, ret);
81. ret = -EBUSY;
82. goto release_regs;
83. }
84. info->clk = clk_get(NULL, "lcd");
85. if (!info->clk || IS_ERR(info->clk)) {
86. printk(KERN_ERR "failed to get lcd clock source\n");
87. ret = -ENOENT;
88. goto release_irq;
89. }
90. clk_enable(info->clk);
91. dprintk("got and enabled clock\n");
92. msleep(1);
93. /* find maximum required memory size for display */
94. for (i = 0; i < mach_info->num_displays; i++) {
95. unsigned long smem_len = mach_info->displays[i].xres;
96. smem_len *= mach_info->displays[i].yres;
97. smem_len *= mach_info->displays[i].bpp;
98. smem_len >>= 3;
99. if (fbinfo->fix.smem_len < smem_len)
100. fbinfo->fix.smem_len = smem_len;
101. }
102. /* Initialize video memory */
103. ret = s3c2410fb_map_video_memory(fbinfo);                                                   //为帧缓冲分配内存空间。同时使用了dma
104. if (ret) {
105. printk(KERN_ERR "Failed to allocate video RAM: %d\n", ret);
106. ret = -ENOMEM;
107. goto release_clock;
108. }
109. dprintk("got video memory\n");
110. fbinfo->var.xres = display->xres;
111. fbinfo->var.yres = display->yres;
112. fbinfo->var.bits_per_pixel = display->bpp;
113. s3c2410fb_init_registers(fbinfo);                                                           //GPIO初始化
114. s3c2410fb_check_var(&fbinfo->var, fbinfo);                                                  //设置fb_var_screeninfo
115. ret = register_framebuffer(fbinfo);                                                         //注册帧缓冲-register_framebuffer
116. if (ret < 0) {
117. printk(KERN_ERR "Failed to register framebuffer device: %d\n",
118. ret);
119. goto free_video_memory;
120. }
121. /* create device files */
122. ret = device_create_file(&pdev->dev, &dev_attr_debug);
123. if (ret) {
124. printk(KERN_ERR "failed to add debug attribute\n");
125. }
126. printk(KERN_INFO "fb%d: %s frame buffer device\n",
127. fbinfo->node, fbinfo->fix.id);
128. return 0;
129. free_video_memory:
130. s3c2410fb_unmap_video_memory(fbinfo);
131. release_clock:
132. clk_disable(info->clk);
133. clk_put(info->clk);
134. release_irq:
135. free_irq(irq, info);
136. release_regs:
137. iounmap(info->io);
138. release_mem:
139. release_resource(info->mem);
140. kfree(info->mem);
141. dealloc_fb:
142. platform_set_drvdata(pdev, NULL);
143. framebuffer_release(fbinfo);
144. return ret;
145. }

s3c2410fb_map_vedio_memory:

1. static int __init s3c2410fb_map_video_memory(struct fb_info *info)
2. {
3. struct s3c2410fb_info *fbi = info->par;
4. dma_addr_t map_dma;
5. unsigned map_size = PAGE_ALIGN(info->fix.smem_len);
6. dprintk("map_video_memory(fbi=%p) map_size %u\n", fbi, map_size);
7. info->screen_base = dma_alloc_writecombine(fbi->dev, map_size,
8. &map_dma, GFP_KERNEL);                                                      //为帧缓冲分配内存空间。同时使用了dma
9. if (info->screen_base) {
10. /* prevent initial garbage on screen */
11. dprintk("map_video_memory: clear %p:%08x\n",
12. info->screen_base, map_size);
13. memset(info->screen_base, 0x00, map_size);
14. info->fix.smem_start = map_dma;
15. dprintk("map_video_memory: dma=%08lx cpu=%p size=%08x\n",
16. info->fix.smem_start, info->screen_base, map_size);
17. }
18. return info->screen_base ? 0 : -ENOMEM;
19. }

分析到这里发现并没有设置帧缓冲的地址：

于是可以通过搜索帧地址来辨别，在哪个函数中实现。

s3c2410fb_set_lcdaddr:

1. static void s3c2410fb_set_lcdaddr(struct fb_info *info)
2. {
3. unsigned long saddr1, saddr2, saddr3;
4. struct s3c2410fb_info *fbi = info->par;
5. void __iomem *regs = fbi->io;
6. saddr1 = info->fix.smem_start >> 1;
7. saddr2 = info->fix.smem_start;
8. saddr2 += info->fix.line_length * info->var.yres;
9. saddr2 >>= 1;
10. saddr3 = S3C2410_OFFSIZE(0) |
11. S3C2410_PAGEWIDTH((info->fix.line_length / 2) & 0x3ff);
12. dprintk("LCDSADDR1 = 0x%08lx\n", saddr1);
13. dprintk("LCDSADDR2 = 0x%08lx\n", saddr2);
14. dprintk("LCDSADDR3 = 0x%08lx\n", saddr3);
15. writel(saddr1, regs + S3C2410_LCDSADDR1);                                  //这里设置了帧缓冲的地址
16. writel(saddr2, regs + S3C2410_LCDSADDR2);
17. writel(saddr3, regs + S3C2410_LCDSADDR3);
18. }

但是如何知道调用顺序呢，可以在函数中调用dump_stack()：

1. Backtrace:
2. [<c0049048>] (dump_backtrace+0x0/0x10c) from [<c0373fac>] (dump_stack+0x18/0x1c)
3. r7:232f3302 r6:5bd42233 r5:00000000 r4:3a352944
4. [<c0373f94>] (dump_stack+0x0/0x1c) from [<c01718c8>] (s3c2410fb_set_par+0x150/0x78c)
5. [<c0171778>] (s3c2410fb_set_par+0x0/0x78c) from [<c016a578>] (fbcon_init+0x42c/0x4b8)
6. [<c016a14c>] (fbcon_init+0x0/0x4b8) from [<c0185800>] (visual_init+0xb8/0x100)
7. [<c0185748>] (visual_init+0x0/0x100) from [<c018a65c>] (take_over_console+0x1f4/0x3d8)
8. r7:00000000 r6:c03a6c90 r5:c05a75a0 r4:00000019
9. [<c018a468>] (take_over_console+0x0/0x3d8) from [<c0167050>] (fbcon_takeover+0x7c/0xd4)
10. [<c0166fd4>] (fbcon_takeover+0x0/0xd4) from [<c016b1b0>] (fbcon_event_notify+0x768/0x7b0)
11. r5:ffffffff r4:00000000
12. [<c016aa48>] (fbcon_event_notify+0x0/0x7b0) from [<c0070784>] (notifier_call_chain+0x54/0x94)
13. [<c0070730>] (notifier_call_chain+0x0/0x94) from [<c0070d08>] (__blocking_notifier_call_chain+0x54/0x6c)
14. r9:c04b5008 r8:00000005 r7:ffffffff r6:c381dd98 r5:c04c5470
15. r4:c04c547c
16. [<c0070cb4>] (__blocking_notifier_call_chain+0x0/0x6c) from [<c0070d40>] (blocking_notifier_call_chain+0x20/0x28)
17. r8:c3842a04 r7:00000000 r6:c0513120 r5:c3842800 r4:c381dd60
18. [<c0070d20>] (blocking_notifier_call_chain+0x0/0x28) from [<c015fc48>] (fb_notifier_call_chain+0x1c/0x24)
19. [<c015fc2c>] (fb_notifier_call_chain+0x0/0x24) from [<c0160cf0>] (register_framebuffer+0x154/0x1fc)
20. [<c0160b9c>] (register_framebuffer+0x0/0x1fc) from [<c0014bbc>] (s3c24xxfb_probe+0x4c4/0x6fc)
21. [<c00146f8>] (s3c24xxfb_probe+0x0/0x6fc) from [<c0014e20>] (s3c2410fb_probe+0x14/0x18)
22. [<c0014e0c>] (s3c2410fb_probe+0x0/0x18) from [<c019369c>] (platform_drv_probe+0x20/0x24)
23. [<c019367c>] (platform_drv_probe+0x0/0x24) from [<c0192694>] (driver_probe_device+0x8c/0x1a0)
24. [<c0192608>] (driver_probe_device+0x0/0x1a0) from [<c019283c>] (__driver_attach+0x94/0x98)
25. [<c01927a8>] (__driver_attach+0x0/0x98) from [<c0191f38>] (bus_for_each_dev+0x6c/0x98)
26. r7:c01927a8 r6:c04c56b8 r5:c381de98 r4:00000000
27. [<c0191ecc>] (bus_for_each_dev+0x0/0x98) from [<c0192514>] (driver_attach+0x20/0x28)
28. r7:c04c56b8 r6:00000000 r5:c04c56b8 r4:c001fc68
29. [<c01924f4>] (driver_attach+0x0/0x28) from [<c0191764>] (bus_add_driver+0xa4/0x244)
30. [<c01916c0>] (bus_add_driver+0x0/0x244) from [<c0192b00>] (driver_register+0x74/0x15c)
31. [<c0192a8c>] (driver_register+0x0/0x15c) from [<c0193a80>] (platform_driver_register+0x6c/0x88)
32. r7:c381c000 r6:00000000 r5:c001fa50 r4:c001fc68
33. [<c0193a14>] (platform_driver_register+0x0/0x88) from [<c0014e38>] (s3c2410fb_init+0x14/0x30)
34. [<c0014e24>] (s3c2410fb_init+0x0/0x30) from [<c0044284>] (do_one_initcall+0x3c/0x1bc)
35. [<c0044248>] (do_one_initcall+0x0/0x1bc) from [<c0008438>] (kernel_init+0x88/0xf4)
36. [<c00083b0>] (kernel_init+0x0/0xf4) from [<c005a2e8>] (do_exit+0x0/0x620)