RK3288 HDMI增加特殊分辨率

转载请注明出处：https://www.cnblogs.com/lialong1st/p/9174475.html

CPU：RK3288

系统：Android 5.1

本帖以 HDMI 800x600p-60 为例，添加新的分辨率。

1、修改文件，打开调试模式，得到 EDID 信息后，记得关闭

diff --git a/kernel/drivers/video/fbmon.c b/kernel/drivers/video/fbmon.c
index 6103fa6..ce9b11e
--- a/kernel/drivers/video/fbmon.c
+++ b/kernel/drivers/video/fbmon.c
@@ -, +, @@
  * EDID parser
  */

-#undef DEBUG  /* define this for verbose EDID parsing output */
+//#undef DEBUG  /* define this for verbose EDID parsing output */
+#define DEBUG

 #ifdef DEBUG
 #define DPRINTK(fmt, args...) printk(fmt,## args)

2、打印出 EDID 信息

[    0.805638] ========================================
[    0.805652] Display Information (EDID)
[    0.805662] ========================================
[    0.805672]    EDID Version 1.3
[    0.805682]    Manufacturer: ROW
[    0.805691]    Model:
[    0.805699]    Serial#:
[    0.805708]    Year:  Week
[    0.805719]    Monitor Name: AAA
[    0.805728]    Display Characteristics:
[    0.805738]       Monitor Operating Limits: From EDID
[    0.805754]            H: -80KHz V: -76Hz DCLK: 160MHz
[    0.805764]       Digital Display Input
      Sync:
[    0.805780]       Max H-size in cm: variable
[    0.805791]       Max V-size in cm: variable
[    0.805801]       Gamma: 1.0
[    0.805813]       DPMS: Active yes, Suspend no, Standby yes
[    0.805823]       Unknown
[    0.805832]       Chroma
[    0.805840]          RedX:     0.636 RedY:     0.349
[    0.805852]          GreenX:   0.290 GreenY:   0.589
[    0.805863]          BlueX:    0.143 BlueY:    0.080
[    0.805875]          WhiteX:   0.313 WhiteY:   0.329
[    0.805886]       First DETAILED Timing is preferred
[    0.805899]    Detailed Timings
[    0.805910]        MHz         +HSync +VSync

[    0.805932]    Supported VESA Modes
[    0.805945]       720x400@70Hz
[    0.805955]       640x480@60Hz
[    0.805964]       640x480@72Hz
[    0.805972]       640x480@75Hz
[    0.805980]       800x600@56Hz
[    0.805988]       800x600@60Hz
[    0.805997]       800x600@72Hz
[    0.806005]       800x600@75Hz
[    0.806014]       Manufacturer's mask: 0
[    0.806023]    Standard Timings
[    0.806034] ========================================

Detailed Timings 是主要的 LCD 参数，Supported VESA Modes 是 LCD 支持的分辨率。

通过源码查看各参数的含义：

路径：kernel/drivers/video/fbmon.c

DPRINTK("      %d MHz ",  PIXEL_CLOCK/);
DPRINTK("%d %d %d %d ", H_ACTIVE, H_ACTIVE + H_SYNC_OFFSET, H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH, H_ACTIVE + H_BLANKING);
DPRINTK("%d %d %d %d ", V_ACTIVE, V_ACTIVE + V_SYNC_OFFSET, V_ACTIVE + V_SYNC_OFFSET + V_SYNC_WIDTH, V_ACTIVE + V_BLANKING);
DPRINTK("%sHSync %sVSync\n\n", (HSYNC_POSITIVE) ? "+" : "-", (VSYNC_POSITIVE) ? "+" : "-");

由此可以得到 LCD 的各参数：

40M = PIXEL_CLOCK = pixclock
 = H_ACTIVE = xres
 = H_ACTIVE + H_SYNC_OFFSET = xres + h_fp =  +
 = H_ACTIVE + H_SYNC_OFFSET + H_SYNC_WIDTH = xres + h_fp + h_pw =  +  +
 = H_ACTIVE + H_BLANKING = xres + h_bp + h_fp + h_pw =  +  +  +
 = V_ACTIVE = yres
 = V_ACTIVE + V_SYNC_OFFSET = yres + v_fp =  +
 = V_ACTIVE + V_SYNC_OFFSET + V_SYNC_WIDTH = yres + v_fp + v_pw =  +  +
 = V_ACTIVE + V_BLANKING = yres + v_bp + v_fp + v_pw =  +  +  +
+HSync = HSYNC_POSITIVE
+VSync = VSYNC_POSITIVE

3、在枚举中增加此分辨率，枚举值为 108，并修改默认分辨率

diff --git a/kernel/drivers/video/rockchip/hdmi/rockchip-hdmi.h b/kernel/drivers/video/rockchip/hdmi/rockchip-hdmi.h
index b5475e4..f31f5b9
--- a/kernel/drivers/video/rockchip/hdmi/rockchip-hdmi.h
+++ b/kernel/drivers/video/rockchip/hdmi/rockchip-hdmi.h
@@ -, +, @@ enum hdmi_video_infomation_code {
HDMI_3840X2160P_30HZ_4_3, /**/
HDMI_3840X2160P_50HZ_4_3,
HDMI_3840X2160P_60HZ_4_3,
+ HDMI_800X600P_60HZ, /**/
};

/* HDMI Extended Resolution */
@@ -, +, @@ struct hdmi {
#define HDMI_AUTO_CONFIG false

/* HDMI default vide mode */
-#define HDMI_VIDEO_DEFAULT_MODE HDMI_1920X1080P_60HZ//HDMI_1280X720P_60HZ
+#define HDMI_VIDEO_DEFAULT_MODE HDMI_800X600P_60HZ//HDMI_1920X1080P_60HZ//HDMI_1280X720P_60HZ
/*HDMI_1920X1080P_60HZ*/
#define HDMI_VIDEO_DEFAULT_COLORMODE HDMI_COLOR_AUTO
#define HDMI_VIDEO_DEFAULT_COLORDEPTH 8

4、将屏参数据添加到数组 static const struct hdmi_video_timing hdmi_mode[] 中

 /* name refresh xres yres pixclock h_bp h_fp v_bp v_fp h_pw v_pw polariry PorI flag vic 2ndvic pixelrepeat interface */

/* 名称 刷新频率 行像素 列像素 像素时钟 水平后沿 水平前沿 垂直后沿 垂直前沿 行同步脉宽 列同步脉宽 极性 扫描方式 标志 枚举值 第二枚举值  像素重复 接口*/

diff --git a/kernel/drivers/video/rockchip/hdmi/rockchip-hdmi-lcdc.c b/kernel/drivers/video/rockchip/hdmi/rockchip-hdmi-lcdc.c
index 63a5cfb..0f920c2
--- a/kernel/drivers/video/rockchip/hdmi/rockchip-hdmi-lcdc.c
+++ b/kernel/drivers/video/rockchip/hdmi/rockchip-hdmi-lcdc.c
@@ -, +, @@ static const struct hdmi_video_timing hdmi_mode[] = {
    { {    "720x576i@50Hz",    ,    ,    ,    ,    ,    ,    ,    ,    ,    ,            ,                ,        },    ,    HDMI_720X576I_50HZ_16_9,    ,    OUT_P888},
    { {    "720x480p@60Hz",    ,    ,    ,    ,    ,    ,    ,    ,    ,    ,            ,                ,        },    ,     HDMI_720X480P_60HZ_16_9,    ,    OUT_P888},
    { {    "720x576p@50Hz",    ,    ,    ,    ,    ,    ,    ,    ,    ,    ,            ,                ,        },    ,    HDMI_720X576P_50HZ_16_9,    ,    OUT_P888},
+   { {    "800x600p@60Hz",    ,    ,    ,    ,    ,    ,    ,    ,    ,   ,    FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,    ,    }, , HDMI_800X600P_60HZ,      ,  OUT_P888},
    { {    "1280x720p@24Hz",   ,    ,   ,    ,    ,   ,  ,    ,    ,    ,    FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,    ,    }, ,  HDMI_1280X720P_24HZ_4_3, ,  OUT_P888},
    { {    "1280x720p@25Hz",   ,    ,   ,    ,    ,   ,  ,    ,    ,    ,    FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,    ,    }, ,  HDMI_1280X720P_25HZ_4_3, ,  OUT_P888},
    { {    "1280x720p@30Hz",   ,    ,   ,    ,    ,   ,  ,    ,    ,    ,    FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,    ,    }, ,  HDMI_1280X720P_30HZ_4_3, ,  OUT_P888},

polariry：水平同步高电平有效和垂直同步高电平有效

PorI：0 为不是隔行扫描。定义文件路径：/kernel/include/uapi/linux/fb.h

flag：不知道什么意思

vic：在分辨率枚举中的编号，本次添加的为 108

5、此时 HDMI 可以正常输入 800x600 的分辨率，但是实际显示可能有问题。

根据显示器的 EDID 修改 dts 中加载的屏参文件，修改值与添加到 HDMI 数组中的相同。

diff --git a/kernel/arch/arm/boot/dts/lcd-800x600.dtsi b/kernel/arch/arm/boot/dts/lcd-800x600.dtsi
index c0baf15..733a157
--- a/kernel/arch/arm/boot/dts/lcd-800x600.dtsi
+++ b/kernel/arch/arm/boot/dts/lcd-800x600.dtsi
@@ -, +, @@
                                clock-frequency = <>;
-                               hactive = <>;
-                               vactive = <>;
-                               hback-porch = <>;
-                               hfront-porch = <>;
-                               vback-porch = <>;
-                               vfront-porch = <>;
-                               hsync-len = <>;
-                               vsync-len = <>;
+                               hactive = <>;
+                               vactive = <>;
+                               hback-porch = <>;
+                               hfront-porch = <>;
+                               vback-porch = <>;
+                               vfront-porch = <>;
+                               hsync-len = <>;
+                               vsync-len = <>;
                                hsync-active = <>;
                                vsync-active = <>;
                                de-active = <>;

6、编译烧录，HDMI 显示正常，确认当前分辨率可以在设置 -> HDMI ->分辨率设置中查看，也可以通过指令查看。

$ cat /sys/class/display/HDMI/mode