UM0851 datasheet(192/245 Pages) STMICROELECTRONICS

192 / 245 page

Audio/video drivers

UM0851

192/245

Doc ID 16604 Rev 2

8.1.2

Software overview

The CLCD device driver sits on top of the CLCD Controller and provides all necessary

functions for a graphic application via the standard Linux framebuffer interface. The CLCD

software system architecture is shown in Figure 52.

Figure 52.

CLCD software architecture

The CLCD device driver for linux is 'drivers/video/amba-clcd.c'.

8.1.3

CLCD device driver interface with framebuffer layer

The framebuffer layer is a part of the Linux kernel and should not be confused with the

CLCD Panel Data Framebuffer register in the CLCD Controller (which is also referred to as

frame buffer memory).

The framebuffer device provides a general abstraction of the graphics hardware and allows

the application software to access the graphics hardware through a well-defined

programming interface, so the application software does not need to know anything about

the low-level part (hardware registers). Figure 53 briefly illustrates the advantage of the

framebuffer layer.

CLCD panel

User space

Kernel space

Hardware

X,GTK,QT

Framebuffer layer

CLCD driver

CLCD

controller

UM0851 Datasheet(PDF) 192 Page - STMicroelectronics