分享DRM Display Driver Development Guide

前言..................................................................................................................................................................................III
目录.................................................................................................................................................................................. IV
1 DRM 概述......................................................................................................................................................................1
1.1 基本概念........................................................................................................................................................... 1
1.2 DRM 显示通路..................................................................................................................................................1
1.3 DRM 驱动和libdrm 交互过程.......................................................................................................................1
2 DRM 驱动......................................................................................................................................................................2
2.1 uboot 驱动....................................................................................................................................................... 2
2.1.1 驱动目录............................................................................................................................................... 2
2.1.2 驱动文件............................................................................................................................................... 2
2.1.3 接口说明............................................................................................................................................... 2
2.2 kernel 驱动...................................................................................................................................................... 3
2.2.1 驱动目录............................................................................................................................................... 3
2.2.2 驱动文件............................................................................................................................................... 3
2.2.3 内核驱动加载流程............................................................................................................................... 4
3 Display feature..........................................................................................................................................................5
3.1 各平台支持的显示接口及属性....................................................................................................................... 5
3.2 最大输出分辨率和协议标准........................................................................................................................... 5
3.2.1 RK3036 平台....................................................................................................................................... 5
3.2.2 RK312X/PX3SE 平台........................................................................................................................5
3.2.3 RK322X/RK312XH 平台..................................................................................................................5
3.2.4 RK3288X 平台.................................................................................................................................... 5
3.2.5 RK3308 平台....................................................................................................................................... 6
3.2.6 RK322XH/RK332X 平台..................................................................................................................6
3.2.7 RK3326/px30 平台........................................................................................................................... 6
3.2.8 RK3368/PX5 平台............................................................................................................................. 6
3.2.9 RK3399 平台....................................................................................................................................... 6
4 硬件相关....................................................................................................................................................................... 6
4.1 RGB 输出/TTL 模式硬件连接......................................................................................................................6
4.1.1 RGB888 24BIT 屏............................................................................................................................. 6
4.1.2 RGB666 18 bit 屏............................................................................................................................. 7
4.1.3 RGB565 16 bit 屏............................................................................................................................. 8
4.1.4 MCU 屏..................................................................................................................................................8
4.2 LVDS Data Mapping...............................................................................................................................10
4.2.1 6 bit output mode...................................................................................................................... 10
4.2.2 8 bit output mode...................................................................................................................... 10
4.2.3 10 bit output mode....................................................................................................................11
5 扫描时序说明.............................................................................................................................................................13
5.1 常见的扫描时序图.........................................................................................................................................13
5.2 DRM 对扫描时序的定义...............................................................................................................................14
5.3 软件配置的对应关系.....................................................................................................................................14
6 常用的debug 手段.................................................................................................................................................. 14
6.1 dump 当前的显示状态.................................................................................................................................14
6.1.1 使用命令.............................................................................................................................................14
6.1.2 参数说明.............................................................................................................................................15
6.2 调整drm log 等级抓log............................................................................................................................16
6.3 查看当前的显示时钟.....................................................................................................................................16
6.4 强行开关显示设备.........................................................................................................................................16
6.5 查看drm buffer 使用情况......................................................................................................................... 17
6.6 查看gpio 的状态.......................................................................................................................................... 17
6.7 modetest 使用............................................................................................................................................. 17
6.8 界面暂停、启动.............................................................................................................................................17
6.9 查看EDID 信息............................................................................................................................................ 18
6.10 查看HDMI 的状态信息.............................................................................................................................18
6.11 Dump 当前显示的buffer.........................................................................................................................18
6.11.1 使用说明.......................................................................................................................................... 18
6.11.2 例子.................................................................................................................................................. 18
7 FAQ..............................................................................................................................................................................18
7.1 uboot logo 切换到内核logo 出现闪屏/无法显示问题.......................................................................... 18
7.1.1 DDR 变频导致................................................................................................................................... 18
7.1.2 clk tree 变化导致............................................................................................................................. 18
7.1.3 时钟被关闭导致.................................................................................................................................19
7.1.4 uboot logo 图片和kernel logo 图片大小不一致......................................................................19
7.1.5 内核初始化过程一些电源/GPIO 被重新初始化...........................................................................19
7.1.6 VOP 优先级配置问题........................................................................................................................19
7.1.7 测试相关电源和信号........................................................................................................................ 19
7.2 如何开关uboot logo 显示......................................................................................................................... 19
7.3 VOP POST_BUF_EMPTY.......................................................................................................................... 20
7.3.1 带宽不够.............................................................................................................................................20
7.3.2 iommu 出错...................................................................................................................................... 20
7.3.3 logic 电压太低...................................................................................................................................20
7.3.4 AFBDC/IFBDC 对齐要求................................................................................................................20
7.4 drm 驱动bind...............................................................................................................................................20
7.5 uboot logo 要求...........................................................................................................................................21
7.6 部分机器开机动画显示异常，桌面显示正常............................................................................................ 21
7.7 显示效果调节.................................................................................................................................................22
7.8 屏无法点亮/休眠唤醒显示异常/不显示问题.............................................................................................22
7.9 rk3308 显示特殊性.....................................................................................................................................22
7.9.1 uboot 显示.........................................................................................................................................22
7.9.2 CMA_SIZE 的修改........................................................................................................................... 22
7.10 OLED 屏余晖确认.......................................................................................................................................23
7.11 各种接口屏配置.......................................................................................................................................... 23
8 参考文档.....................................................................................................................................................................23

Rockchip DRM Display Driver Development Guide V1.0.pdf (1.38 MB, 下载次数: 1)

2023-2-14 17:35 上传

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