Datasheet

14
AVR32416
32105-AVR32-07/08
Parameter Description
default_bpp
Bits per pixel to use. Possible values are 1, 2, 4, 8, 15, 16, 24
and 32. The memory layout for these values is described in the
datasheet of the device. For instance 32bit means 3x8bit for
the three colors red, green, blue and empty 8bit at the end.
default_dmacon
Setting ATMEL_LCDC_DMAEN is mandatory in order to
enable the LCD controller DMA engine. The
A
TMEL_LCDC_DMA2DEN will activate the double buffering of
the frame buffer.
default_lcdcon2
This is the default configuration of the LCD controller register
“LCDCON2”. The bit-fields INVFRAME, INVLINE and
PIXELSIZE are automatically set according to the video mode
settings. All other settings of this register may be configured by
using the available macros in the include/video/atmel_lcdc.h
file.
default_monspecs Pointer to the monitor specifications structure.
guard_time
Delay in frame periods between applying control signals to the
LCD module and setting PWR high, and between setting
PWR low and removing control signals from LCD module.
lcd_wiring_mode
Specifies the hardware wiring of the LCD. Possible values are
A
TMEL_LCDC_WIRING_BGR and
A
TMEL_LCDC_WIRING_RGB (see chapter “3.6.2.1 RGB
frame buffer layout support with hardware swap” for more
details)
3.6.2 Special configurations
Sometimes a more specific setup of the LCD controller is needed. This is the case
when exact timings are needed or unused pins of the LCD controller must be used for
other things. Also the LCD controller may need a higher priority for accesses to the
memory to keep the DMA in sync. Another special setup needs to be done to support
RGB frame buffer layout without a software swap. These extended configurations will
be discussed in the next chapters.
3.6.2.1 RGB frame buffer layout support with hardware swap
The needed hardware swapping was already described in the hardware section of
this document. Since the frame buffer driver can not know about the actual wiring of
the LCD display the driver needs be made aware of it. Therefore the variable
lcd_wiring_mode is available in the struct atmel_lcdfb_info that was already described
in chapter 3.6.1. This variable should be available since the kernel version 2.6.26.
Use the macro ATMEL_LCDC_WIRING_BGR to inform the frame buffer driver of a
normal wiring of the LCD. The macro ATMEL_LCDC_WIRING_RGB will tell the frame
buffer driver that the colors have been swapped in hardware. For more information
about the hardware wiring that needs to be done take a look at chapter “2.1.2.1 Using
a hardware swap to get RGB frame buffer data ordering”.
3.6.2.2 Freeing unused LCD pins
The standard LCD controller setup reserves all 24 data lines for the LCD.
This may not
be necessary if a display is used that does not need all 24 data lines. If these pins should be