一. 簡介

• 專欄總目錄
• 本文是基于RK3588平臺，MIPI屏調試總結。

二. MIPI屏幕調試

2.1 調試總覽，調試步驟分析

• 步驟 ① 先將背光點亮
• 步驟 ② 根據屏幕的規格書配置dsi1_panel節點
• 步驟 ③ 打開對應的dsi節點，開機logo
• 步驟 ④ 編譯燒寫，調試屏幕

2.2 DTS配置

#include "rk3588-evb.dtsi"   //引用了dsi1_panel 節點

2.2.1 步驟 ① 背光配置：

dsi1_backlight: dsi1-backlight {
		status = "okay";
		compatible = "pwm-backlight";
		pwms = < &pwm2 0 25000 0 >;
		brightness-levels = <
			  0  20  20  21  21  22  22  23
			 23  24  24  25  25  26  26  27
			 27  28  28  29  29  30  30  31
			 31  32  32  33  33  34  34  35
			 35  36  36  37  37  38  38  39
			 40  41  42  43  44  45  46  47
			 48  49  50  51  52  53  54  55
			 56  57  58  59  60  61  62  63
			 64  65  66  67  68  69  70  71
			 72  73  74  75  76  77  78  79
			 80  81  82  83  84  85  86  87
			 88  89  90  91  92  93  94  95
			 96  97  98  99 100 101 102 103
			104 105 106 107 108 109 110 111
			112 113 114 115 116 117 118 119
			120 121 122 123 124 125 126 127
			128 129 130 131 132 133 134 135
			136 137 138 139 140 141 142 143
			144 145 146 147 148 149 150 151
			152 153 154 155 156 157 158 159
			160 161 162 163 164 165 166 167
			168 169 170 171 172 173 174 175
			176 177 178 179 180 181 182 183
			184 185 186 187 188 189 190 191
			192 193 194 195 196 197 198 199
			200 201 202 203 204 205 206 207
			208 209 210 211 212 213 214 215
			216 217 218 219 220 221 222 223
			224 225 226 227 228 229 230 231
			232 233 234 235 236 237 238 239
			240 241 242 243 244 245 246 247
			248 249 250 251 252 253 254 255
		>;
		default-brightness-level = < 200 >;
		enable-gpios = < &gpio2 RK_PC2 GPIO_ACTIVE_HIGH >;
		pinctrl-names = "default";
		pinctrl-0 = < &dsi1_backlight_en >;
	};

2.2.2 步驟 ② 根據datasheet配置屏幕節點：

• 屏幕上電初始化時序的配置教程見 RK3588-MIPI屏幕調試筆記:RK3588-MIPI-DSI之LCD上電初始化時序
• 屏幕的時序參數配置教程見 RK3588-MIPI屏幕調試筆記:RK3588-MIPI-DSI之屏參配置
• 屏幕dts配置如下：

  &dsi1_panel {
  	power-supply = < &vcc_lcd_mipi1 >;  //使用gpio模擬regulator
  	reset-gpios = < &gpio2 RK_PC1 GPIO_ACTIVE_LOW >;
  	backlight = < &dsi1_backlight >;
  	pinctrl-names = "default";
  	pinctrl-0 = < &dsi1_lcd_rst_gpio >;
  
  	panel-init-sequence = [
  			13 00 02 B0 01
  			13 00 02 C0 26
  			13 00 02 C1 10
  			13 00 02 C2 0E
  			13 00 02 C3 00
  			13 00 02 C4 00
  			13 00 02 C5 23
  			13 00 02 C6 11
  			13 00 02 C7 22
  			13 00 02 C8 20
  			13 00 02 C9 1E
  			13 00 02 CA 1C
  			13 00 02 CB 0C
  			13 00 02 CC 0A
  			13 00 02 CD 08
  			13 00 02 CE 06
  			13 00 02 CF 18
  			13 00 02 D0 02
  			13 00 02 D1 00
  			13 00 02 D2 00
  			13 00 02 D3 00
  			13 00 02 D4 26
  			13 00 02 D5 0F
  			13 00 02 D6 0D
  			13 00 02 D7 00
  			13 00 02 D8 00
  			13 00 02 D9 23
  			13 00 02 DA 11
  			13 00 02 DB 21
  			13 00 02 DC 1F
  			13 00 02 DD 1D
  			13 00 02 DE 1B
  			13 00 02 DF 0B
  			13 00 02 E0 09
  			13 00 02 E1 07
  			13 00 02 E2 05
  			13 00 02 E3 17
  			13 00 02 E4 01
  			13 00 02 E5 00
  			13 00 02 E6 00
  			13 00 02 E7 00
  			13 00 02 B0 03
  			13 00 02 BE 04
  			13 00 02 B9 40
  			13 00 02 CC 88
  			13 00 02 C8 0C
  			13 00 02 C9 07
  			13 00 02 CD 01
  			13 00 02 CA 40
  			13 00 02 CE 1A
  			13 00 02 CF 60
  			13 00 02 D2 08
  			13 00 02 D3 08
  			13 00 02 DB 01
  			13 00 02 D9 06
  			13 00 02 D4 00
  			13 00 02 D5 01
  			13 00 02 D6 04
  			13 00 02 D7 03
  			13 00 02 C2 00
  			13 00 02 C3 0E
  			13 00 02 C4 00
  			13 00 02 C5 0E
  			13 00 02 DD 00
  			13 00 02 DE 0E
  			13 00 02 E6 00
  			13 00 02 E7 0E
  			13 00 02 C2 00
  			13 00 02 C3 0E
  			13 00 02 C4 00
  			13 00 02 C5 0E
  			13 00 02 DD 00
  			13 00 02 DE 0E
  			13 00 02 E6 00
  			13 00 02 E7 0E
  			13 00 02 B0 06
  			13 00 02 C0 A5
  			13 00 02 D5 1C
  			13 00 02 C0 00
  			13 00 02 B0 00
  			13 00 02 BD 30
  
  			13 00 02 F9 5C
  			13 00 02 C2 14
  			13 00 02 C4 14
  			13 00 02 BF 15
  			13 00 02 C0 0C
  
  
  			13 00 02 B0 00
  			13 00 02 B1 79
  			13 00 02 BA 8F
  
  			05 C8 01 11
  			05 32 01 29
  		];
  
  		panel-exit-sequence = [
  			05 00 01 28
  			05 00 01 10
  		];
  
  		disp_timings1: display-timings {    
  			native-mode = < &dsi1_timing0 >;
  			dsi1_timing0: timing0 {
  				clock-frequency = < 159400000 >;   //根據屏幕的時序參數表配置
  				hactive = < 1200 >;
  				vactive = < 1920 >;
  				hfront-porch = < 80 >;
  				hsync-len = < 1 >;
  				hback-porch = < 60 >;
  				vfront-porch = < 35 >;
  				vsync-len = < 1 >;
  				vback-porch = < 25 >;
  				hsync-active = < 0 >;
  				vsync-active = < 0 >;
  				de-active = < 0 >;
  				pixelclk-active = < 1 >;
  			};
  		};
  };
  

2.2.3 步驟 ③ 打開對應的dsi節點，開機logo

//打開背光的pwm節點

&pwm2 {

status = "okay";

pinctrl-names = "active";

pinctrl-0 = < &pwm2m2_pins >;

};

//在dsi1上接了一個mipi屏，這個配置開啟dsi1

&dsi1 {

status = "okay";

};

&mipi_dcphy1 {

status = "okay";

};

//默認dsi配置vp2和vp3上面，這里配置為dsi使用vp3，可以根據屏的分辨率來確認使用vp2還是vp3，vp2支持4K，vp3只支持 2048x1536

&dsi1_in_vp2 {

status = "disabled";

};

&dsi1_in_vp3 {

status = "okay";

};

//配置dsi1顯示開機logo

&route_dsi1 {

status = "okay";

connect = < &vp3_out_dsi1 >;

};

2.3 調試命令

查看顯示信息命令：

cat /sys/kernel/debug/dri/0/summary

2.4 問題總結

調試過程中遇到的問題：一開始很久沒亮，測量了電源電壓和波形都正常。后來換了一組板子和屏幕做對比。最后是因為屏幕的座子沒焊接好，二是接MIPI屏幕的排線太長會影響數據傳輸。換了一根短的線之后屏幕亮起。

審核編輯：湯梓紅