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Device Drivers  --->
	Graphics support  --->
		 Frame buffer Devices  --->
		 	<*> Samsung S3C framebuffer support  //在配置上还是有这个，那样只要把设备端配置好就行
 [*] Bootup logo  --->	

exynosdrm-$(CONFIG_DRM_EXYNOS_FIMD)	+= exynos_drm_fimd.o
exynosdrm-$(CONFIG_DRM_EXYNOS_DPI)	+= exynos_drm_dpi.o

Device Drivers  ---> 
	Graphics support  --->
		Direct Rendering Manager  ---> 
			<*> Direct Rendering Manager (XFree86 4.1.0 and higher DRI support)  ---> 
				[*]     Exynos DRM FIMD
 				[*]     EXYNOS DRM parallel output support

fimd: fimd@11c00000 {
		compatible = "samsung,exynos4210-fimd";
		interrupt-parent = <&combiner>;
		reg = <0x11c00000 0x20000>;
		interrupt-names = "fifo", "vsync", "lcd_sys";
		interrupts = <11 0>, <11 1>, <11 2>;
		clocks = <&clock CLK_SCLK_FIMD0>, <&clock CLK_FIMD0>;
		clock-names = "sclk_fimd", "fimd";
		power-domains = <&pd_lcd0>;
		iommus = <&sysmmu_fimd0>;
		samsung,sysreg = <&sys_reg>;
		status = "disabled"; 
	};

&fimd {
		pinctrl-0 = <&lcd_clk &lcd_data24 &pwm1_out>;
		pinctrl-names = "default";
		samsung,invert-vclk;     //vclk翻转
		status = "okay";
	};

display-timings {
		native-mode = <&timing0>;
		timing0: timing {
		  pixelclk-active = <1>;
			clock-frequency = <33000000>;
			hactive = <800>;
			vactive = <480>;
			hfront-porch = <80>;
			hback-porch = <36>;
			hsync-len = <10>;
			vback-porch = <15>;
			vfront-porch = <1>;
			vsync-len = <8>;
		};
	};

[    1.475756] [drm] Initialized drm 1.1.0 20060810
[    1.481573] exynos-drm exynos-drm: bound 11c00000.fimd (ops fimd_component_ops)
[    1.486849] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[    1.493444] [drm] No driver support for vblank timestamp query.
[    1.499351] [drm] Initialized exynos 1.0.0 20110530 on minor 0

&fimd {
		pinctrl-0 = <&lcd_clk &lcd_data24 &pwm1_out>;
		pinctrl-names = "default";
		samsung,invert-vclk;
		status = "okay";
		display-timings {
		native-mode = <&timing0>;
		timing0: timing {
		  pixelclk-active = <1>;
			clock-frequency = <33000000>;
			hactive = <800>;
			vactive = <480>;
			hfront-porch = <80>;
			hback-porch = <36>;
			hsync-len = <10>;
			vback-porch = <15>;
			vfront-porch = <1>;
			vsync-len = <8>;
		};
	};
};

[    1.469053] [drm] Initialized drm 1.1.0 20060810
[    1.473455] drivers/gpu/drm/exynos/exynos_drm_fimd.c fimd_probe 999
[    1.479165] lcd_clk = 1500000  添加的打印信息
[    1.561894] exynos-drm exynos-drm: bound 11c00000.fimd (ops fimd_component_ops)
[    1.569049] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[    1.575641] [drm] No driver support for vblank timestamp query.
[    1.591038] Console: switching to colour frame buffer device 114x34
[    1.595286] exynos-drm exynos-drm: fb0:  frame buffer device  （看到这一句就表示创建出fb0了）
[    1.595342] exynos-drm exynos-drm: registered panic notifier
[    1.614515] [drm] Initialized exynos 1.0.0 20110530 on minor 0
....  //中间省略

Myroot /# cat /sys/class/graphics/fb0/virtual_size
800,480  //打印出来的信息对应hactive = <800>;vactive = <480>;也就是说设置成功了。

	
static void __init exynos4_clk_init(struct device_node *np,enum exynos4_soc soc)
    {
    struct clk *mout_mpll_user_t 	= NULL;
	struct clk *mount_fimd0 	= NULL;
	struct clk *sclk_fimd0  	= NULL;    
    .....
    /* Frequency up to 800Mhz */
	/* code start... */
    	pr_info("%s %s %d\n",__FILE__,__FUNCTION__,__LINE__);
	mout_mpll_user_t = __clk_lookup("mout_mpll_user_t");
	if (IS_ERR(mout_mpll_user_t)) {
		pr_info("failed to get mout_mpll_user_t clock\n");
		return;
	}
	pr_info("%s %s %d\n",__FILE__,__FUNCTION__,__LINE__);
	mount_fimd0 = __clk_lookup("mout_fimd0");
	if (IS_ERR(mount_fimd0)) {
		pr_info("failed to get mout_fimd0 clock\n");
		return ;
	}
	pr_info("%s %s %d\n",__FILE__,__FUNCTION__,__LINE__);
	sclk_fimd0 = __clk_lookup("sclk_fimd0");
	if (IS_ERR(sclk_fimd0)) {
		pr_info("failed to get sclk_fimd0 clock\n");
		return ;
	}
	clk_set_parent(mount_fimd0,mout_mpll_user_t);
	
	ret = clk_set_rate(mount_fimd0,800000000);
	if(ret){
		pr_info("failed to clock set rate\n");	
		return ;
	}
	pr_info("%s %s %d\n",__FILE__,__FUNCTION__,__LINE__);
	ret = clk_set_rate(sclk_fimd0,800000000);
	if(ret){
		pr_info("failed to clock set rate\n");	
		return ;
	}

	pr_info("mout_mpll_user_t = %ld mount_fimd0 = %ld sclk_fimd0 = %ld\n",clk_get_rate(mout_mpll_user_t),clk_get_rate(mount_fimd0),clk_get_rate(sclk_fimd0));
	 /* code end... */
}

[    1.605811] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[    1.612402] [drm] No driver support for vblank timestamp query.
[    1.622973] lcd_clk = 800000000     //成功升频到800Mhz
[    1.627903] Console: switching to colour frame buffer device 114x34
[    1.659366] exynos-drm exynos-drm: fb0:  frame buffer device
[    1.665007] exynos-drm exynos-drm: registered panic notifier
[    1.684532] [drm] Initialized exynos 1.0.0 20110530 on minor 0

&fimd {
	pinctrl-0 = <&lcd_clk &lcd_data24>;
	pinctrl-names = "default";
	status = "okay";
	samsung,invert-vclk;   //翻转
	display-timings {
		native-mode = <&timing0>;
		timing0: timing {
			hsync-active = <1>;   //行同步信号开始位高
			vsync-active = <1>;
			de-active = <0>;									
			clock-frequency = <33000000>;
			hactive = <800>;
			vactive = <480>;
			hfront-porch = <80>;
			hback-porch = <36>;
			hsync-len = <10>;
			vback-porch = <15>;
			vfront-porch = <1>;
			vsync-len = <8>;
		};
	};
};