9.3.4 EPDC Waveform Loading
The EPDC driver requires a waveform file for proper operation. This waveform file
contains the waveform information needed to generate the waveforms that drive updates
to the E Ink panel. A pointer to the waveform file data is programmed into the EPDC
before the first update is performed.
There are two options for selecting a waveform file:
1. Select one of the default waveform files included in this BSP and built into the
kernel.
2. Use a new waveform file that is specific to the E Ink panel being used.
The waveform file is loaded by the EPDC driver using the Linux firmware APIs.
9.3.4.1 Using a Default Waveform File
The quickest and easiest way to get started using an E Ink panel and the EPDC driver is
to use one of the default waveform files provided in the Linux BSP. This should enable
updates to several different types of E Ink panel without a panel-specific waveform file.
The drawback is that optimal quality should not be expected. Typically, using a non-
panel-specific waveform file for an E Ink panel results in more ghosting artifacts and
overall poorer color quality.
The following default waveform files included in the BSP reside in firmware/imx/:
• epdc_E60_V110.fw - Default waveform for the 6.0 inch V110 E Ink panel.
• epdc_E60_V220.fw - Default waveform for the 6.0 inch V220 E Ink panel (supports
animation mode updates).
• epdc_E97_V110.fw - Default waveform for the 9.7 inch V110 E Ink panel.
• epdc_E060SCM.fw - Default waveform for the 6.0 inch Pearl E Ink panel (supports
animation mode updates).
The EPDC driver attempts to load a waveform file with the name "imx/
epdc_[panel_name].fw", where panel_name refers to the string specified in the
fb_videomode
name
field. This panel_name information should be provided to the EPDC
driver through the kernel command line parameters described in the preceding chapter.
For example, to load the epdc_E060SCM.fw default firmware file for a Pearl panel, set
the EPDC kernel command line paratmeter to the following:
video=mxcepdcfb:E060SCM,bpp=16
Chapter 9 Electrophoretic Display Controller (EPDC) Frame Buffer Driver
i.MX 6Solo/6DualLite Linux Reference Manual, Rev. L3.0.35_4.1.0, 09/2013
Freescale Semiconductor, Inc.
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