| /*LCD FrameBuffer設備探測的實現，注意這里使用一個__devinit宏，到lcd_fb_remove接口函數實現的地方講解*/
static int __devinit lcd_fb_probe(struct platform_device *pdev)
{
????int i;
????int ret;
????struct resource?*res;??/*用來保存從LCD平臺設備中獲取的LCD資源*/
????struct fb_info??*fbinfo;?/*FrameBuffer驅動所對應的fb_info結構體*/
????struct s3c2410fb_mach_info?*mach_info;?/*保存從內核中獲取的平臺設備數據*/
????struct my2440fb_var?*fbvar;?/*上面定義的驅動程序全局變量結構體*/
????struct s3c2410fb_display?*display;?/*LCD屏的配置信息結構體，該結構體定義在mach-s3c2410/include/mach/fb.h中*/
????/*獲取LCD硬件相關信息數據，在前面講過內核使用s3c24xx_fb_set_platdata函數將LCD的硬件相關信息保存到
???? 了LCD平臺數據中，所以這里我們就從平臺數據中取出來在驅動中使用*/
????mach_info = pdev->dev.platform_data;
????if(mach_info == NULL)
????{
????????/*判斷獲取數據是否成功*/
????????dev_err(&pdev->dev, "no platform data for lcd/n");
????????return -EINVAL;
????}
????/*獲得在內核中定義的FrameBuffer平臺設備的LCD配置信息結構體數據*/
????display = mach_info->displays + mach_info->default_display; ??? /*給fb_info分配空間，大小為my2440fb_var結構的內存，framebuffer_alloc定義在fb.h中在fbsysfs.c中實現*/
????fbinfo = framebuffer_alloc(sizeof(struct my2440fb_var), &pdev->dev);
????if(!fbinfo)
????{
????????dev_err(&pdev->dev, "framebuffer alloc of registers failed/n");
????????ret = -ENOMEM;
????????goto err_noirq;
????}
????platform_set_drvdata(pdev, fbinfo);/*重新將LCD平臺設備數據設置為fbinfo，好在后面的一些函數中來使用*/
????/*這里的用途其實就是將fb_info的成員par(注意是一個void類型的指針)指向這里的私有變量結構體fbvar，
???? 目的是到其他接口函數中再取出fb_info的成員par，從而能繼續使用這里的私有變量*/
????fbvar = fbinfo->par;
????fbvar->dev = &pdev->dev;
????/*在系統定義的LCD平臺設備資源中獲取LCD中斷號,platform_get_irq定義在platform_device.h中*/
????fbvar->lcd_irq_no = platform_get_irq(pdev, 0);
????if(fbvar->lcd_irq_no < 0)
????{
????????/*判斷獲取中斷號是否成功*/
????????dev_err(&pdev->dev, "no lcd irq for platform/n");
????????return -ENOENT;
????}
????/*獲取LCD平臺設備所使用的IO端口資源，注意這個IORESOURCE_MEM標志和LCD平臺設備定義中的一致*/
????res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
????if(res == NULL)
????{
????????/*判斷獲取資源是否成功*/
????????dev_err(&pdev->dev, "failed to get memory region resource/n");
????????return -ENOENT;
????}
????/*申請LCD IO端口所占用的IO空間(注意理解IO空間和內存空間的區別),request_mem_region定義在ioport.h中*/
????fbvar->lcd_mem = request_mem_region(res->start, res->end - res->start + 1, pdev->name);
????if(fbvar->lcd_mem == NULL)
????{
????????/*判斷申請IO空間是否成功*/
????????dev_err(&pdev->dev, "failed to reserve memory region/n");
????????return -ENOENT;
????}
????/*將LCD的IO端口占用的這段IO空間映射到內存的虛擬地址，ioremap定義在io.h中
???? 注意：IO空間要映射后才能使用，以后對虛擬地址的操作就是對IO空間的操作*/
????fbvar->lcd_base = ioremap(res->start, res->end - res->start + 1);
????if(fbvar->lcd_base == NULL)
????{
????????/*判斷映射虛擬地址是否成功*/
????????dev_err(&pdev->dev, "ioremap() of registers failed/n");
????????ret = -EINVAL;
????????goto err_nomem;
????}
????/*從平臺時鐘隊列中獲取LCD的時鐘，這里為什么要取得這個時鐘，從LCD屏的時序圖上看，各種控制信號的延遲
???? 都跟LCD的時鐘有關。系統的一些時鐘定義在arch/arm/plat-s3c24xx/s3c2410-clock.c中*/
????fbvar->lcd_clock = clk_get(NULL, "lcd");
????if(!fbvar->lcd_clock)
????{
????????/*判斷獲取時鐘是否成功*/
????????dev_err(&pdev->dev, "failed to find lcd clock source/n");
????????ret = -ENOENT;
????????goto err_nomap;
????}
????/*時鐘獲取后要使能后才可以使用，clk_enable定義在arch/arm/plat-s3c/clock.c中*/
????clk_enable(fbvar->lcd_clock);
????/*申請LCD中斷服務，上面獲取的中斷號lcd_fb_irq，使用快速中斷方式:IRQF_DISABLED
???? 中斷服務程序為:lcd_fb_irq，將LCD平臺設備pdev做參數傳遞過去了*/
????ret = request_irq(fbvar->lcd_irq_no, lcd_fb_irq, IRQF_DISABLED, pdev->name, fbvar);
????if(ret)
????{
????????/*判斷申請中斷服務是否成功*/
????????dev_err(&pdev->dev, "IRQ%d error %d/n", fbvar->lcd_irq_no, ret);
????????ret = -EBUSY;
????????goto err_noclk;
????}
????/*好了，以上是對要使用的資源進行了獲取和設置。下面就開始初始化填充fb_info結構體*/
????/*首先初始化fb_info中代表LCD固定參數的結構體fb_fix_screeninfo*/
????/*像素值與顯示內存的映射關系有5種，定義在fb.h中。現在采用FB_TYPE_PACKED_PIXELS方式，在該方式下，
????像素值與內存直接對應，比如在顯示內存某單元寫入一個"1"時，該單元對應的像素值也將是"1"，這使得應用層
????把顯示內存映射到用戶空間變得非常方便。Linux中當LCD為TFT屏時，顯示驅動管理顯示內存就是基于這種方式*/
????strcpy(fbinfo->fix.id, driver_name);/*字符串形式的標識符*/
????fbinfo->fix.type = FB_TYPE_PACKED_PIXELS;
????fbinfo->fix.type_aux = 0;/*以下這些根據fb_fix_screeninfo定義中的描述，當沒有硬件是都設為0*/
????fbinfo->fix.xpanstep = 0;
????fbinfo->fix.ypanstep = 0;
????fbinfo->fix.ywrapstep= 0;
????fbinfo->fix.accel = FB_ACCEL_NONE; ??? /*接著，再初始化fb_info中代表LCD可變參數的結構體fb_var_screeninfo*/
????fbinfo->var.nonstd??????????= 0;
????fbinfo->var.activate????????= FB_ACTIVATE_NOW;
????fbinfo->var.accel_flags?????= 0;
????fbinfo->var.vmode???????????= FB_VMODE_NONINTERLACED;
????fbinfo->var.xres????????????= display->xres;
????fbinfo->var.yres????????????= display->yres;
????fbinfo->var.bits_per_pixel??= display->bpp; ??? /*指定對底層硬件操作的函數指針, 因內容較多故其定義在第③步中再講*/
????fbinfo->fbops???????????????= &my2440fb_ops; ??? /*初始化色調色板(顏色表)為空*/
????for(i = 0; i < 256; i++)
????{
????????fbvar->palette_buffer[i] = PALETTE_BUFF_CLEAR;
????}
????for (i = 0; i < mach_info->num_displays; i++) /*fb緩存的長度*/
????{
????????/*計算FrameBuffer緩存的最大大小，這里右移3位(即除以8)是因為色位模式BPP是以位為單位*/
????????unsigned long smem_len = (mach_info->displays[i].xres * mach_info->displays[i].yres * mach_info->displays[i].bpp) >> 3;
????????if(fbinfo->fix.smem_len < smem_len)
????????{
????????????fbinfo->fix.smem_len = smem_len;
????????}
????}
????/*初始化LCD控制器之前要延遲一段時間*/
????msleep(1);
????/*初始化完fb_info后，開始對LCD各寄存器進行初始化，其定義在后面講到*/
????my2440fb_init_registers(fbinfo);
????/*初始化完寄存器后，開始檢查fb_info中的可變參數，其定義在后面講到*/
????my2440fb_check_var(fbinfo);
????
????/*申請幀緩沖設備fb_info的顯示緩沖區空間，其定義在后面講到*/
????ret = my2440fb_map_video_memory(fbinfo);
????if (ret)
????{
????????dev_err(&pdev->dev, "failed to allocate video RAM: %d/n", ret);
????????ret = -ENOMEM;
????????goto err_nofb;
????}
????/*最后，注冊這個幀緩沖設備fb_info到系統中, register_framebuffer定義在fb.h中在fbmem.c中實現*/
????ret = register_framebuffer(fbinfo);
????if (ret < 0)
????{
????????dev_err(&pdev->dev, "failed to register framebuffer device: %d/n", ret);
????????goto err_video_nomem;
????}
????/*對設備文件系統的支持(對設備文件系統的理解請參閱：嵌入式Linux之我行——設備文件系統剖析與使用)
???? 創建frambuffer設備文件，device_create_file定義在linux/device.h中*/
????ret = device_create_file(&pdev->dev, &dev_attr_debug);
????if (ret)
????{
????????dev_err(&pdev->dev, "failed to add debug attribute/n");
????}
????return 0;
/*以下是上面錯誤處理的跳轉點*/
err_nomem:
????release_resource(fbvar->lcd_mem);
????kfree(fbvar->lcd_mem);
err_nomap:
????iounmap(fbvar->lcd_base);
err_noclk:
????clk_disable(fbvar->lcd_clock);
????clk_put(fbvar->lcd_clock);
err_noirq:
????free_irq(fbvar->lcd_irq_no, fbvar);
err_nofb:
????platform_set_drvdata(pdev, NULL);
????framebuffer_release(fbinfo);
err_video_nomem:
????my2440fb_unmap_video_memory(fbinfo);
????return ret;
}
/*LCD中斷服務程序*/
static irqreturn_t lcd_fb_irq(int irq, void *dev_id)
{
????struct my2440fb_var????*fbvar = dev_id;
????void __iomem *lcd_irq_base;
????unsigned long lcdirq;
????/*LCD中斷掛起寄存器基地址*/
????lcd_irq_base = fbvar->lcd_base + S3C2410_LCDINTBASE;
????/*讀取LCD中斷掛起寄存器的值*/
????lcdirq = readl(lcd_irq_base + S3C24XX_LCDINTPND);
????/*判斷是否為中斷掛起狀態*/
????if(lcdirq & S3C2410_LCDINT_FRSYNC)
????{
????????/*填充調色板*/
????????if (fbvar->palette_ready)
????????{
????????????my2440fb_write_palette(fbvar);
????????}
????????/*設置幀已插入中斷請求*/
????????writel(S3C2410_LCDINT_FRSYNC, lcd_irq_base + S3C24XX_LCDINTPND);
????????writel(S3C2410_LCDINT_FRSYNC, lcd_irq_base + S3C24XX_LCDSRCPND);
????}
????return IRQ_HANDLED;
}
/*填充調色板*/
static void my2440fb_write_palette(struct my2440fb_var *fbvar)
{
????unsigned int i;
????void __iomem *regs = fbvar->lcd_base;
????fbvar->palette_ready = 0;
????for (i = 0; i < 256; i++)
????{
????????unsigned long ent = fbvar->palette_buffer[i];
????????if (ent == PALETTE_BUFF_CLEAR)
????????{
????????????continue;
????????}
????????writel(ent, regs + S3C2410_TFTPAL(i));
????????if (readw(regs + S3C2410_TFTPAL(i)) == ent)
????????{
????????????fbvar->palette_buffer[i] = PALETTE_BUFF_CLEAR;
????????}
????????else
????????{
????????????fbvar->palette_ready = 1;
????????}
????}
}
/*LCD各寄存器進行初始化*/
static int my2440fb_init_registers(struct fb_info *fbinfo)
{
????unsigned long flags;
????void __iomem *tpal;
????void __iomem *lpcsel;
????/*從lcd_fb_probe探測函數設置的私有變量結構體中再獲得LCD相關信息的數據*/
????struct my2440fb_var????*fbvar = fbinfo->par;
????struct s3c2410fb_mach_info *mach_info = fbvar->dev->platform_data;
????/*獲得臨時調色板寄存器基地址，S3C2410_TPAL宏定義在mach-s3c2410/include/mach/regs-lcd.h中。
????注意對于lpcsel這是一個針對三星TFT屏的一個專用寄存器，如果用的不是三星的TFT屏應該不用管它。*/
????tpal = fbvar->lcd_base + S3C2410_TPAL;
????lpcsel = fbvar->lcd_base + S3C2410_LPCSEL;
????/*在修改下面寄存器值之前先屏蔽中斷，將中斷狀態保存到flags中*/
????local_irq_save(flags);
????/*這里就是在上一篇章中講到的把IO端口C和D配置成LCD模式*/
????modify_gpio(S3C2410_GPCUP, mach_info->gpcup, mach_info->gpcup_mask);
????modify_gpio(S3C2410_GPCCON, mach_info->gpccon, mach_info->gpccon_mask);
????modify_gpio(S3C2410_GPDUP, mach_info->gpdup, mach_info->gpdup_mask);
????modify_gpio(S3C2410_GPDCON, mach_info->gpdcon, mach_info->gpdcon_mask);
????/*恢復被屏蔽的中斷*/
????local_irq_restore(flags);
????writel(0x00, tpal);/*臨時調色板寄存器使能禁止*/
????writel(mach_info->lpcsel, lpcsel);/*在上一篇中講到過，它是三星TFT屏的一個寄存器，這里可以不管*/
????return 0;
}
/*該函數實現修改GPIO端口的值，注意第三個參數mask的作用是將要設置的寄存器值先清零*/
static inline void modify_gpio(void __iomem *reg, unsigned long set, unsigned long mask)
{
????unsigned long tmp;
????tmp = readl(reg) & ~mask;
????writel(tmp | set, reg);
}
/*檢查fb_info中的可變參數*/
static int my2440fb_check_var(struct fb_info *fbinfo)
{
????unsigned i;
????/*從lcd_fb_probe探測函數設置的平臺數據中再獲得LCD相關信息的數據*/
????struct fb_var_screeninfo *var = &fbinfo->var;/*fb_info中的可變參數*/
????struct my2440fb_var????*fbvar = fbinfo->par;/*在lcd_fb_probe探測函數中設置的私有結構體數據*/
????struct s3c2410fb_mach_info *mach_info = fbvar->dev->platform_data;/*LCD的配置結構體數據，這個配置結構體的賦值在上一篇章的"3. 幀緩沖設備作為平臺設備"中*/
????struct s3c2410fb_display *display = NULL;
????struct s3c2410fb_display *default_display = mach_info->displays + mach_info->default_display;
????int type = default_display->type;/*LCD的類型，看上一篇章的"3. 幀緩沖設備作為平臺設備"中的type賦值是TFT類型*/
????/*驗證X/Y解析度*/
????if (var->yres == default_display->yres &&
????????var->xres == default_display->xres &&
????????var->bits_per_pixel == default_display->bpp)
????{
????????display = default_display;
????}
????else
????{
????????for (i = 0; i < mach_info->num_displays; i++)
????????{
????????????if (type == mach_info->displays[i].type &&
???????????? var->yres == mach_info->displays[i].yres &&
???????????? var->xres == mach_info->displays[i].xres &&
???????????? var->bits_per_pixel == mach_info->displays[i].bpp)
????????????{
????????????????display = mach_info->displays + i;
????????????????break;
????????????}
????????}
????}
????if (!display)
????{
????????return -EINVAL;
????}
????/*配置LCD配置寄存器1中的5-6位(配置成TFT類型)和配置LCD配置寄存器5*/
????fbvar->regs.lcdcon1 = display->type;
????fbvar->regs.lcdcon5 = display->lcdcon5;
????/* 設置屏幕的虛擬解析像素和高度寬度 */
????var->xres_virtual = display->xres;
????var->yres_virtual = display->yres;
????var->height = display->height;
????var->width = display->width;
????/* 設置時鐘像素，行、幀切換值，水平同步、垂直同步長度值 */
????var->pixclock = display->pixclock;
????var->left_margin = display->left_margin;
????var->right_margin = display->right_margin;
????var->upper_margin = display->upper_margin;
????var->lower_margin = display->lower_margin;
????var->vsync_len = display->vsync_len;
????var->hsync_len = display->hsync_len;
????/*設置透明度*/
????var->transp.offset = 0;
????var->transp.length = 0;
????/*根據色位模式(BPP)來設置可變參數中R、G、B的顏色位域。對于這些參數值的設置請參考CPU數據
????手冊中"顯示緩沖區與顯示點對應關系圖"，例如在上一篇章中我就畫出了8BPP和16BPP時的對應關系圖*/
????switch (var->bits_per_pixel)
????{
????????case 1:
????????case 2:
????????case 4:
????????????var->red.offset??= 0;
????????????var->red.length??= var->bits_per_pixel;
????????????var->green?????? = var->red;
????????????var->blue??????? = var->red;
????????????break;
????????case 8:/* 8 bpp 332 */
????????????if (display->type != S3C2410_LCDCON1_TFT)
????????????{
????????????????var->red.length?????= 3;
????????????????var->red.offset?????= 5;
????????????????var->green.length???= 3;
????????????????var->green.offset???= 2;
????????????????var->blue.length????= 2;
????????????????var->blue.offset????= 0;
????????????}else{
????????????????var->red.offset?????= 0;
????????????????var->red.length?????= 8;
????????????????var->green????????? = var->red;
????????????????var->blue?????????? = var->red;
????????????}
????????????break;
????????case 12:/* 12 bpp 444 */
????????????var->red.length???????? = 4;
????????????var->red.offset???????? = 8;
????????????var->green.length?????? = 4;
????????????var->green.offset?????? = 4;
????????????var->blue.length??????? = 4;
????????????var->blue.offset??????? = 0;
????????????break;
????????case 16:/* 16 bpp */
????????????if (display->lcdcon5 & S3C2410_LCDCON5_FRM565)
????????????{
????????????????/* 565 format */
????????????????var->red.offset??????= 11;
????????????????var->green.offset????= 5;
????????????????var->blue.offset???? = 0;
????????????????var->red.length??????= 5;
????????????????var->green.length????= 6;
????????????????var->blue.length???? = 5;
????????????} else {
????????????????/* 5551 format */
????????????????var->red.offset??????= 11;
????????????????var->green.offset????= 6;
????????????????var->blue.offset???? = 1;
????????????????var->red.length??????= 5;
????????????????var->green.length????= 5;
????????????????var->blue.length???? = 5;
????????????}
????????????break;
????????case 32:/* 24 bpp 888 and 8 dummy */
????????????var->red.length????????= 8;
????????????var->red.offset????????= 16;
????????????var->green.length????? = 8;
????????????var->green.offset????? = 8;
????????????var->blue.length?????? = 8;
????????????var->blue.offset?????? = 0;
????????????break;
????}
????return 0;
}
/*申請幀緩沖設備fb_info的顯示緩沖區空間*/
static int __init my2440fb_map_video_memory(struct fb_info *fbinfo)
{
????dma_addr_t map_dma;/*用于保存DMA緩沖區總線地址*/
????struct my2440fb_var????*fbvar = fbinfo->par;/*獲得在lcd_fb_probe探測函數中設置的私有結構體數據*/
????unsigned map_size = PAGE_ALIGN(fbinfo->fix.smem_len);/*獲得FrameBuffer緩存的大小, PAGE_ALIGN定義在mm.h中*/
????/*將分配的一個寫合并DMA緩存區設置為LCD屏幕的虛擬地址(對于DMA請參考DMA相關知識)
????dma_alloc_writecombine定義在arch/arm/mm/dma-mapping.c中*/
????fbinfo->screen_base = dma_alloc_writecombine(fbvar->dev, map_size, &map_dma, GFP_KERNEL);
????if (fbinfo->screen_base)
????{
????????/*設置這片DMA緩存區的內容為空*/
????????memset(fbinfo->screen_base, 0x00, map_size);
????????/*將DMA緩沖區總線地址設成fb_info不可變參數中framebuffer緩存的開始位置*/
????????fbinfo->fix.smem_start = map_dma;
????}
????return fbinfo->screen_base ? 0 : -ENOMEM;
}
/*釋放幀緩沖設備fb_info的顯示緩沖區空間*/
static inline void my2440fb_unmap_video_memory(struct fb_info *fbinfo)
{
????struct my2440fb_var????*fbvar = fbinfo->par;
????unsigned map_size = PAGE_ALIGN(fbinfo->fix.smem_len);
????/*跟申請DMA的地方想對應*/
????dma_free_writecombine(fbvar->dev, map_size, fbinfo->screen_base, fbinfo->fix.smem_start);
}
/*LCD FrameBuffer設備移除的實現，注意這里使用一個__devexit宏，和lcd_fb_probe接口函數相對應。
??在Linux內核中，使用了大量不同的宏來標記具有不同作用的函數和數據結構，這些宏在include/linux/init.h
??頭文件中定義，編譯器通過這些宏可以把代碼優化放到合適的內存位置，以減少內存占用和提高內核效率。
??__devinit、__devexit就是這些宏之一，在probe()和remove()函數中應該使用__devinit和__devexit宏。
??又當remove()函數使用了__devexit宏時，則在驅動結構體中一定要使用__devexit_p宏來引用remove()，
??所以在第①步中就用__devexit_p來引用lcd_fb_remove接口函數。*/
static int __devexit lcd_fb_remove(struct platform_device *pdev)
{
????struct fb_info *fbinfo = platform_get_drvdata(pdev);
????struct my2440fb_var????*fbvar = fbinfo->par;
????/*從系統中注銷幀緩沖設備*/
????unregister_framebuffer(fbinfo);
????/*停止LCD控制器的工作*/
????my2440fb_lcd_enable(fbvar, 0);
????/*延遲一段時間，因為停止LCD控制器需要一點時間 */
????msleep(1);
????/*釋放幀緩沖設備fb_info的顯示緩沖區空間*/
????my2440fb_unmap_video_memory(fbinfo);
????/*將LCD平臺數據清空和釋放fb_info空間資源*/
????platform_set_drvdata(pdev, NULL);
????framebuffer_release(fbinfo);
????/*釋放中斷資源*/
????free_irq(fbvar->lcd_irq_no, fbvar);
????/*釋放時鐘資源*/
????if (fbvar->lcd_clock)
????{
????????clk_disable(fbvar->lcd_clock);
????????clk_put(fbvar->lcd_clock);
????????fbvar->lcd_clock = NULL;
????}
????/*釋放LCD IO空間映射的虛擬內存空間*/
????iounmap(fbvar->lcd_base);
????/*釋放申請的LCD IO端口所占用的IO空間*/
????release_resource(fbvar->lcd_mem);
????kfree(fbvar->lcd_mem);
????return 0;
}
/*停止LCD控制器的工作*/
static void my2440fb_lcd_enable(struct my2440fb_var *fbvar, int enable)
{
????unsigned long flags;
????/*在修改下面寄存器值之前先屏蔽中斷，將中斷狀態保存到flags中*/
????local_irq_save(flags);
????if (enable)
????{
????????fbvar->regs.lcdcon1 |= S3C2410_LCDCON1_ENVID;
????}
????else
????{
????????fbvar->regs.lcdcon1 &= ~S3C2410_LCDCON1_ENVID;
????}
????writel(fbvar->regs.lcdcon1, fbvar->lcd_base + S3C2410_LCDCON1);
????/*恢復被屏蔽的中斷*/
????local_irq_restore(flags);
}
/*對LCD FrameBuffer平臺設備驅動電源管理的支持,CONFIG_PM這個宏定義在內核中*/
#ifdef CONFIG_PM
/*當配置內核時選上電源管理，則平臺設備的驅動就支持掛起和恢復功能*/
static int lcd_fb_suspend(struct platform_device *pdev, pm_message_t state)
{
????/*掛起LCD設備，注意這里掛起LCD時并沒有保存LCD控制器的各種狀態，所以在恢復后LCD不會繼續顯示掛起前的內容
???? 若要繼續顯示掛起前的內容，則要在這里保存LCD控制器的各種狀態，這里就不講這個了，以后講到電源管理再講*/
????struct fb_info *fbinfo = platform_get_drvdata(pdev);
????struct my2440fb_var????*fbvar = fbinfo->par;
????/*停止LCD控制器的工作*/
????my2440fb_lcd_enable(fbvar, 0);
????msleep(1);
????/*停止時鐘*/
????clk_disable(fbvar->lcd_clock);
????return 0;
}
static?int lcd_fb_resume(struct platform_device *pdev)
{
????/*恢復掛起的LCD設備*/
????struct fb_info *fbinfo = platform_get_drvdata(pdev);
????struct my2440fb_var????*fbvar = fbinfo->par;
????/*開啟時鐘*/
????clk_enable(fbvar->lcd_clock);
????/*初始化LCD控制器之前要延遲一段時間*/
????msleep(1);
????/*恢復時重新初始化LCD各寄存器*/
????my2440fb_init_registers(fbinfo);
????/*重新激活fb_info中所有的參數配置，該函數定義在第③步中再講*/
????my2440fb_activate_var(fbinfo);
????/*正與掛起時講到的那樣，因為沒保存掛起時LCD控制器的各種狀態，
????所以恢復后就讓LCD顯示空白，該函數定義也在第③步中再講*/
????my2440fb_blank(FB_BLANK_UNBLANK, fbinfo);
????return 0;
}
#else
/*如果配置內核時沒選上電源管理,則平臺設備的驅動就不支持掛起和恢復功能,這兩個函數也就無需實現了*/
#define lcd_fb_suspend????NULL
#define lcd_fb_resume????NULL
#endif
??? fbinfo->flags?????????????? = FBINFO_FLAG_DEFAULT; ??? fbinfo->pseudo_palette????? = &fbvar->pseudo_pal; ? |
