Hi Andre,
On 2/19/21 12:37 PM, Andre Przywara wrote:
On Fri, 19 Feb 2021 11:12:08 +0100 Giulio Benetti giulio.benetti@benettiengineering.com wrote:
Hi,
On 2/19/21 2:44 AM, Andre Przywara wrote:
On Fri, 19 Feb 2021 00:26:19 +0100 Giulio Benetti giulio.benetti@benettiengineering.com wrote:
Hi Giulio,
From: Giulio Benetti giulio.benetti@micronovasrl.com
Add support for Micronova srl s027_3 board by adding new vendor/board folders and using in local Makefile the already present board/sunxi/Makefile. The reason is that s027_3 needs a pin to be asserted to enable lcd before setting controller up and sunxi board doesn't provide a way to do this customization.
Have you tried CONFIG_VIDEO_LCD_POWER?
Yes, I already use that for DISPONOFF.
So what are these pins for, exactly? Backlight? A regulator to provide power to the LCD?
It's the power rail for LCD.
If you grep for "gpio.CONFIG" in sunxi_display.c, there are more GPIOs that we set, for various reasons. Can you pick some from there, and set them in your defconfig?
Unfortunately my LCD_PWR drives a P-MOS so it must be inverted, while LCD0_DISPONOFF can be meant as a lcd reset.
So I introduce CONFIG_VIDEO_LCD_POWER_ACTIVE_LOW for my board to work locally.
Would it make sense to send a patch for this for supporting my board? Or do I wait for you patchset [1] to be applied?
I am strongly against introducing per-board code files, and we definitely won't introduce them just for one GPIO.
I knew it was a strange hack, but I have 2 different pins to be set high before init video controller. Another idea that comes into my mind is to handle CONFIG_VIDEO_LCD_POWER as a gpio list and iterate/enable, what about that?
Do you really need *two* pins to switch the LCD power supply?
I've messed up names, I need only one pin for LCD power supply(the on with P-MOS) but another to enable it(DISPONOFF). But here the problem was that LCD power supply is active low.
If yes, this might be an option. But I guess at this point we want to go more a DT route.
Yes, agree.
Speaking of which, I don't see any video output device in the DT, I guess you just rely on simplefb.
Yes, simplefb for u-boot while...
But given that there is no bridge or it seems to be transparent, at least, you might be able to describe this in the DT as well, so Linux can use its own display driver?
for Linux I use 4 different fdt overlays using fe,be,tcon and simple-panel.
Then we might be able to find a more sustainable solution, based on pins in the DT.
Yes
Cheers, Andre
P.S. Can you please try to apply
[1]:
https://patchwork.ozlabs.org/project/uboot/patch/20210205010748.2646-1-andre... This would be merged around the same time, and I am curious if this still works with an LCD.
For sure I will, I was waiting for this and I've also started to port it a bit but I have not much time and then you added a patch. I'm going to test it and report. If it doesn't work I'll try to fix it for having s027_3 board added using DT then.
Best regards!