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
