On Thu, Nov 18, 2021 at 4:53 AM Marek Vasut <marex@xxxxxxx> wrote: > > On 11/18/21 2:25 AM, Tim Harvey wrote: > > Greetings, > > > > I'm trying to get a RPI 7" touchscreen display working on an IMX8MM > > board and while I've been able to get the MIPI DSI display and > > backlight working I still can't seem to figure out the touch > > controller. > > > > It's supposed to have an FT5406 controller on it without an interrupt > > so I added polling support drivers/input/touchscreen/edt-ft5x06.c > > which I was able to verify using another touchscreen with that > > controller but when reading data from the FT5406 on the RPI controller > > the data does not make sense. > > > > These panels appear to route the I2C from the FT5406 to a STM32F103 > > MPU that then provides a different I2C slave interface to the 15pin > > connector that I'm connected to. On that I2C interface I see an i2c > > slave at 0x45 which is managed by the regulator driver Marek wrote > > (drivers/regulator/rpi-panel-attiny-regulator.c) and there is also an > > i2c slave at 0x38 which I assumed was the FT5406 but I believe the MPU > > is perhaps obfuscating that touch data. > > > > Anyone have any ideas on how to make that touch controller useful? > > Look around: > https://github.com/dh-electronics/meta-dhsom-stm32-bsp/blob/dunfell-3.1/recipes-kernel/linux/linux-stable/5.10/dh-stm32mp1-dhsom/0038-ARM-dts-stm32-Add-AV96-DTO-for-DH-644-100-DSI-mezzan.patch Marek, Thanks. This dt overlay actually disables the touchscreen controller with a note that the IRQ must be hooked up to work. Did you actually wire up an IRQ and get it to work? I implemented polling mode for the controller but the data did not make sense. This dt overlay also interests me as I am also wanting to get some overlays in the kernel tree [1]. I'm curious if you have any thoughts on why there are currently no overlays in the mainline tree. 1 - https://lore.kernel.org/linux-arm-kernel/20211115202426.16114-1-tharvey@xxxxxxxxxxxxx/T/
