Tool/software: Linux
Hi there
We have a custom Board with an LCD, based on AM3352 running linux.
For power consumption optimization we will use the predefined standby Mode in linux
"echo standby > /sys/power/state" which will stops the A8 Core and the M3 will listen to the wakeup sources and resume the A8 on an event.
We need to display an image on the LCD during standby.
I got the LCD Subsystem running again, by patching the M3 Firmware and enabling there in the CM_PER Register the LCD Clocks (0x44e00018 and 0x44e00148)
This leads to a running Pixel Clock, Hsync and Vsync Pulses.
Unfortunately no data is present on the LCD_Data[x] Pins.
Is there any possibility to get data Displayed through the LCD DMA in Standby?
I also tried to switch the DMA Base and Ceiling of the LCD Controller to some Registers accessilbe by the M3, which can be modified by JTAG. But also with present and accessible Data from the M3, no Data is outputed on the LCD_Data Pins.
We like to display the last Image in the framebuffer.
Do we need to prevent the DDR3 from self retention mode to deliver data to the LCD DMA?
Basically I'm interrested if its possible to get the LCD subsystem running in standby mode and output an image on the LCD.
Many thanks for your response.
