硬件平台：mini2440 + TD035STED4  软件平台：linux-2.6.32.2 日期：2012/07/04

首先看驱动模块的初始化函数：

/* drivers/video/s3c2410fb.c */

   1119 int __init s3c2410fb_init(void)
   1120 {
   1121         int ret = platform_driver_register(&s3c2410fb_driver);
   1122
   1123         if (ret == 0)
   1124                 ret = platform_driver_register(&s3c2412fb_driver);
   1125
   1126         return ret;
   1127 }
   1128
   1129 static void __exit s3c2410fb_cleanup(void)
   1130 {
   1131         platform_driver_unregister(&s3c2410fb_driver);
   1132         platform_driver_unregister(&s3c2412fb_driver);
   1133 }

初始化函数里面就注册了一个平台设备驱动。

再来看驱动模块卸载函数：

   1129 static void __exit s3c2410fb_cleanup(void)
   1130 {
   1131         platform_driver_unregister(&s3c2410fb_driver);
   1132         platform_driver_unregister(&s3c2412fb_driver);
   1133 }

卸载函数里面注销平台设备驱动。

s3c2440自然采用的是s3c2410fb_driver，我们来看这个结构的定义：

   1097 static struct platform_driver s3c2410fb_driver = {
   1098         .probe          = s3c2410fb_probe,
   1099         .remove         = s3c2410fb_remove,
   1100         .suspend        = s3c2410fb_suspend,
   1101         .resume         = s3c2410fb_resume,
   1102         .driver         = {
   1103                 .name   = "s3c2410-lcd",
   1104                 .owner  = THIS_MODULE,
   1105         },
   1106 };

我们看driver中的name字段为s3c2410-lcd，那自然去找与之对应的平台设备。

我们在devs.c中找到了这个平台设备的定义：

/* arch/arm/plat-s3c24xx/devs.c */

    141 /* LCD Controller */
    142
    143 static struct resource s3c_lcd_resource[] = {
    144         [0] = {
    145                 .start = S3C24XX_PA_LCD,
    146                 .end   = S3C24XX_PA_LCD + S3C24XX_SZ_LCD - 1,
    147                 .flags = IORESOURCE_MEM,
    148         },
    149         [1] = {
    150                 .start = IRQ_LCD,
    151                 .end   = IRQ_LCD,
    152                 .flags = IORESOURCE_IRQ,
    153         }
    154
    155 };
    156
    157 static u64 s3c_device_lcd_dmamask = 0xffffffffUL;
    158
    159 struct platform_device s3c_device_lcd = {
    160         .name             = "s3c2410-lcd",
    161         .id               = -1,
    162         .num_resources    = ARRAY_SIZE(s3c_lcd_resource),
    163         .resource         = s3c_lcd_resource,
    164         .dev              = {
    165                 .dma_mask               = &s3c_device_lcd_dmamask,

    166                 .coherent_dma_mask      = 0xffffffffUL
    167         }
    168 };
    169
    170 EXPORT_SYMBOL(s3c_device_lcd);

平台设备也有了，平台设备注册进了内核之后，那自然会调用驱动中的probe函数。

    815 static char driver_name[] = "s3c2410fb";
    816
    817 static int __init s3c24xxfb_probe(struct platform_device *pdev,
    818                                   enum s3c_drv_type drv_type)
    819 {
    820         struct s3c2410fb_info *info;
    821         struct s3c2410fb_display *display;
    822         struct fb_info *fbinfo;
    823         struct s3c2410fb_mach_info *mach_info;
    824         struct resource *res;
    825         int ret;
    826         int irq;
    827         int i;
    828         int size;
    829         u32 lcdcon1;
    830
    831         mach_info = pdev->dev.platform_data;
    832         if (mach_info == NULL) {
    833                 dev_err(&pdev->dev,
    834                         "no platform data for lcd, cannot attachn");
    835                 return -EINVAL;
    836         }
    837
    838         if (mach_info->default_display >= mach_info->num_displays) {
    839                 dev_err(&pdev->dev, "default is %d but only %d displaysn",
    840                         mach_info->default_display, mach_info->num_displays);
    841                 return -EINVAL;

    842         }
    843
    844         display = mach_info->displays + mach_info->default_display;
    845
    846         irq = platform_get_irq(pdev, 0);
    847         if (irq < 0) {
    848                 dev_err(&pdev->dev, "no irq for devicen");
    849                 return -ENOENT;
    850         }
    851
    852         fbinfo = framebuffer_alloc(sizeof(struct s3c2410fb_info), &pdev->dev);
    853         if (!fbinfo)
    854                 return -ENOMEM;
    855
    856         platform_set_drvdata(pdev, fbinfo);
    857
    858         info = fbinfo->par;
    859         info->dev = &pdev->dev;
    860         info->drv_type = drv_type;
    861
    862         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    863         if (res == NULL) {
    864                 dev_err(&pdev->dev, "failed to get memory registersn");
    865                 ret = -ENXIO;
    866                 goto dealloc_fb;