DRM详解，针对intel平台linux内核中的DRM的详解

Linux DRM Developer's Guide

Jesse Barnes

Initial version

Intel Corporation

<jesse.barnes@intel.com>

Laurent Pinchart

Copyright © 2008-2009, 2012 Intel Corporation, Laurent Pinchart

The contents of this file may be used under the terms of the GNU General Public License version 2 (the "GPL") as distributed in the kernel source

COPYING file.

Revision History

Revision 1.0 2012-07-13 LP

Added extensive documentation about driver internals.

Table of Contents

1. Introduction

The Translation Table Manager (TTM)

The Graphics Execution Manager (GEM)

Frame Buffer Creation

Output Polling

CRTCs (struct drm_crtc)

Planes (struct drm_plane)

Encoders (struct drm_encoder)

Encoder Helper Operations

Connector Helper Operations

Modeset Helper Functions Reference

fbdev Helper Functions Reference

Display Port Helper Functions Reference

File Operations

IOCTLs

suited to 3D graphics acceleration. Graphics drivers in the kernel may make use of DRM functions to make tasks like memory management, interrupt

handling and DMA easier, and provide a uniform interface to applications.

A note on versions: this guide covers features found in the DRM tree, including the TTM memory manager, output configuration and mode setting,

and the new vblank internals, in addition to all the regular features found in current kernels.

[Insert diagram of typical DRM stack here]

Chapter 2. DRM Internals

Table of Contents

Driver Initialization

KMS Initialization and Cleanup

Vertical Blanking

Open/Close, File Operations and IOCTLs

This chapter documents DRM internals relevant to driver authors and developers working to add support for the latest features to existing drivers.

initializing core services. Subsequent sections cover core internals in more detail, providing implementation notes and examples.

At the core of every DRM driver is a drm_driver structure. Drivers typically statically initialize a drm_driver structure, and then pass it to one of the

drm_*_init()

functions to register it with the DRM subsystem.

The drm_driver structure contains static information that describes the driver and features it supports, and pointers to methods that the DRM core will

call to implement the DRM API. We will first go through the drm_driver static information fields, and will then describe individual operations in

details as they get used in later sections.

Driver Information

Driver Features

Drivers inform the DRM core about their requirements and supported features by setting appropriate flags in the

driver_features

field. Since those