Chapter 5
Electrophoretic Display Controller (EPDC) Frame
Buffer Driver
5.1 Introduction
The Electrophoretic Display Controller (EPDC) is a direct-drive active matrix EPD
controller designed to drive E Ink EPD panels supporting a wide variety of TFT
backplanes. The EPDC framebuffer driver acts as a standard Linux frame buffer device
while also supporting a set of custom API extensions, accessible from user space (via
IOCTL) or another kernel module (via direct function call) in order to provide the user
with access to EPD-specific functionality. The EPDC driver is abstracted from any
specific E Ink panel type, providing flexibility to work with a range of E Ink panel types
and specifications.
The EPDC driver supports the following features:
• Support for EPDC driver as a loadable or built-in module.
• Support for RGB565 and Y8 frame buffer formats.
• Support for full and partial EPD screen updates.
• Support for up to 256 panel-specific waveform modes.
• Support for automatic optimal waveform selection for a given update.
• Support for synchronization by waiting for a specific update request to complete.
• Support for screen updates from an alternate (overlay) buffer.
• Support for automated collision handling.
• Support for 64 simultaneous update regions.
• Support for pixel inversion in a Y8 frame buffer format.
• Support for 90, 180, and 270 degree HW-accelerated frame buffer rotation.
• Support for panning (y-direction only).
• Support for automated full and partial screen updates through the Linux
fb_deferred_io mechanism.
• Support for three EPDC driver display update schemes: Snapshot, Queue, and Queue
and Merge.
i.MX 6SoloLite Linux Reference Manual, Rev. L3.0.35_4.1.0, 09/2013
Freescale Semiconductor, Inc.
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