基于VS-RK3288 RK平臺LCD調(diào)試說明
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RK3288
2020-07-27 14:45 上傳
前言
LVDS調(diào)試
dts實(shí)例
screen_type
lvds_format
clock-frequency
out-face
其它參數(shù)
EDP調(diào)試
本篇博文使用Rockchip平臺RK3288主控,向大家分享自己總結(jié)的Rockchip平臺LCD調(diào)試的一些經(jīng)驗(yàn)。
Platform : Rockchip
Soc : RK3288
System : Android 7.1
RK3288的LCD調(diào)試,根據(jù)屏幕規(guī)格書對dts作相應(yīng)的修改基本都可點(diǎn)亮,配置也較為簡單,有幾個(gè)概念容易混淆,單純的點(diǎn)屏基本上不需要了解相關(guān)的LVDS,EDP協(xié)議等。本篇博客大致講述RK平臺LVDS、EDP屏的調(diào)試經(jīng)驗(yàn),協(xié)議部分不會涉及,MIPI屏部分暫時(shí)還未深入了解。 前言在fb驅(qū)動這塊,大致分為了四部分,rk_screen首先會讀取dts中screen信息,傳給screen_type驅(qū)動(本例也就是rk32_lvds.c),這些信息最終都會被fb獲取。詳細(xì)的流程分析請參考博文:RK平臺fb源碼分析系列 LVDS調(diào)試dts實(shí)例
貼一個(gè)LVDS屏參的實(shí)例,僅供參考: disp_timings: display-timings { native-mode = <&timing0>; timing0: timing0 { screen-type = <SCREEN_LVDS>; lvds-format = <LVDS_8BIT_2>; out-face = <OUT_P888>; color-mode = <COLOR_RGB>; clock-frequency = <43000000>; //43000000 hactive = <1024>; vactive = <600>; hback-porch = <100>; hfront-porch = <60>; vback-porch = <10>; vfront-porch = <8>; hsync-len = <5>; vsync-len = <2>; hsync-active = <0>; vsync-active = <0>; de-active = <0>; pixelclk-active = <1>; swap-rb = <0>; swap-rg = <0>; swap-gb = <0>; }; };
參數(shù)看起來挺多的,其實(shí)真正需要改的一般不多。那究竟哪些都需要修改呢?這當(dāng)然是根據(jù)不同的LCD參考其規(guī)格書修改的,dts中需要重點(diǎn)關(guān)注的有以下幾個(gè)參數(shù):
screen_type,lvds-format,out-face,clock-frequency,hactive,vactive,hbp,hfp,vbp,vfp screen_type
screen-type表示屏幕類型(RGB,LVDS,EDP,MIPI,HDMI,MCU),如果該屏幕為LVDS屏,則screen-type就應(yīng)該取值為SCREEN_LVDS。如果是RGB屏幕,則screen-type取值為SCREEN_RGB。screen-type的值有以下幾種:SCREEN_RGB,SCREEN_LVDS(SCREEN_DUAL_LVDS,SCREEN_LVDS_10BIT,SCREEN_DUAL_LVDS_10BIT),SCREEN_HDMI,SCREEN_MIPI,SCREEN_DUAL_MIPI、SCREEN_EDP#define SCREEN_NULL 0#define SCREEN_RGB 1#define SCREEN_LVDS 2#define SCREEN_DUAL_LVDS 3#define SCREEN_MCU 4#define SCREEN_TVOUT 5#define SCREEN_HDMI 6#define SCREEN_MIPI 7#define SCREEN_DUAL_MIPI 8#define SCREEN_EDP 9#define SCREEN_TVOUT_TEST 10#define SCREEN_LVDS_10BIT 11#define SCREEN_DUAL_LVDS_10BIT 12
lvds_format
lvds-format表示LVDS的數(shù)據(jù)方式,只有在該屏幕是LVDS屏的時(shí)候該參數(shù)才有效。該值需要結(jié)合屏幕和LVDS在硬件上的連接方式來定義。lvds_format的值有以下幾種:LVDS_8BIT_1、LVDS_8BIT_2、LVDS_8BIT_3、LVDS_6BIT。#define LVDS_8BIT_1 0#define LVDS_8BIT_2 1#define LVDS_8BIT_3 2#define LVDS_6BIT 3#define LVDS_10BIT_1 4#define LVDS_10BIT_2 5
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