Hello,
I have built a reference image (Build a Reference Image with Yocto Project/OpenEmbedded | Toradex Developer Center) using BSP 2.8, and need to customize the following items:
- enable Atmel touch driver in the device tree to use the capacitive touch display sold by Toradex
- Set CONFIG_PREEMPT in the Kernel
To do so, I have followed to guide to build the Linux Kernel from source code (Build U-Boot and Linux Kernel from Source Code | Toradex Developer Center) and edited the device tree.
The problem is that the touch screen does not work.
There is an issue which I suspect could be the problem: When I try to build the device tree with the command make DTC_FLAGS=“-@” <device-tree.dtb> (setting any existing device-tree.dtb file), the following error occurs:
./scripts/dtc/dtc: invalid option -- '@'
[...... ]
Error: unknown option
scripts/Makefile.lib:313: recipe for target 'arch/arm/boot/dts/imx6q-apalis-eval.dtb' failed
make[1]: *** [arch/arm/boot/dts/imx6q-apalis-eval.dtb] Error 1
arch/arm/Makefile:336: recipe for target 'imx6q-apalis-eval.dtb' failed
This seems to be the very same error that I’ve had about a year ago, which was resolved back then: Build device tree: dtc: invalid option -- '@'
There is one thing that is unclear to me: I have the Ixora V1.2 carrier board. In the image created for BSP2.8, there is no dtb - file for v1.2 (dtb-files in BSP2.8, located in Apalis-iMX6_Qt5-X11-Image.bootfs.tar.xz: imx6q-apalis-ixora.dtb, imx6q-apalis-ixora-v1.1.dtb, imx6q-apalis-eval.dtb).
Which one is being used by my system?
After deploying the Kernel and the Kernel modules (I have build the device tree with make dtbs due to the “invalid option – ‘@’” - error but maybe this is not the right way to do ), the following messages appear during boot:
[... ]
[ OK [ 5.415506] atmel_mxt_ts: module verification failed: signature and/or required key missing - tainting kernel
] Reached target Paths.
[... ]
[ 5.603709] atmel_mxt_ts 1-004a: __mxt_read_reg: i2c transfer failed (-6)
[ 5.604038] atmel_mxt_ts 1-004a: mxt_bootloader_read: i2c recv failed (-6)
[ 5.604044] atmel_mxt_ts 1-004a: Trying alternate bootloader address
[ 5.604369] atmel_mxt_ts 1-004a: mxt_bootloader_read: i2c recv failed (-6)
(looks similar to Problem with 10.1" capacitive touch and Apalis iMX6 on Ixora v1.1)
I am sure that it is not a hardware problem, because the touch screen works if I flash and run the BSP5 multimedia image.
About a year ago, I got the touch screen to work with BSP2.8 (same hardware), but I didn’t make a proper backup of that image while starting to work with the Toradex modules (touch screen does not work when deploying the image I thought I had used back then).
Hardware and Software being used:
Linux Yocto, Apalis-iMX6_Qt5-X11-Image 2.8b7
Apalis iMX6
Ixora Carrier Board V1.2
Capacitive Touch Display 7" (Capacitive Touch Display - 7 inch)
Thank you for your help!