Hi folks,
I am trying to get the Ilitek ILI2511 I2C touchscreen driver working on a Jetson Nano Dev Kit running JP5, using a device tree overlay on top of a known-working base device tree generated by the jetson-io tool and I am getting a rather unhelpful error message (FDT_ERR_NOTFOUND) when runing fdtoverlay. Wondering if you could help me troubleshoot this.
Jetpack and Kernel Version:
$ sudo apt-cache show nvidia-jetpack | grep Version
Version: 5.1.3-b29
$ uname -a
Linux nvdk-1 5.10.192-tegra #1 SMP PREEMPT Tue Apr 23 17:12:18 PDT 2024 aarch64 aarch64 aarch64 GNU/Linux
The ili210x kernel module is compiled and loaded:
$ lsmod | grep ili
ili210x 16384 0
The 40P header is configured using the jetson-io tool to enable I2C and a few other peripherals, this resulted in the DTB kernel_tegra234-p3767-0003-p3768-0000-a0-user-custom.dtb being generated and an entry being added to /boot/extlinux/extlinux.conf.
To ensure I2C works, I’ve connected a 24 series EEPROM and it is indeed detected:
$ sudo i2cdetect -y -r 7
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: 50 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
(Side note: jetson-io refers to the I2C port on 40P header pins 3,5 as i2c8 but the i2cdetect tool thinks this is port 7)
With I2C working, I created a very simple overlay:
/dts-v1/;
/ {
overlay-name = "DTS Overlay Test";
compatible = "nvidia,p3768-0000+p3767-0003";
fragment@0 {
target-path = "/";
__overlay__ {
custom-board-version = "V1";
};
};
};
Compiled and merged it with the base DTB:
dtc -I dts -O dtb version-overlay.dts -o version-overlay.dtb
fdtoverlay -i kernel_tegra234-p3767-0003-p3768-0000-a0-user-custom.dtb -o custom-board-v1.dtb version-overlay.dtb
Copied this merged DTB to /boot and referenced it in the entry I created in /boot/extlinux/extlinux.conf and restarted the devkit.
Confirmed that the merged device tree worked:
cat /proc/device-tree/custom-board-version
V1
So, at this point I am confident that fdtoverlay works, and I can boot this board with my custom DTB.
Next step is to work on the ILI2511 overlay, here’s the physical connections I am using:
I2C SDA PDD.02 GP16_I2C8_DAT 40P Header Physical Pin 3
I2C SCL PDD.01 GP15_I2C8_CLK 40P Header Physical Pin 5
Interrupt PY.00 GP36_SPI3_CLK 40P Header Physical Pin 13
Reset PY.04 GP40_SPI3_CS1_N 40P Header Physical Pin 16
I notice that we need to use pin numbers in the DTS, so used the following to get the correct GPIO numbers:
Interrupt: PY.00
$ sudo cat /sys/kernel/debug/gpio | grep PY.00
gpio-470 (PY.00 )
Reset: PY.04
$ sudo cat /sys/kernel/debug/gpio | grep PY.04
gpio-474 (PY.04 )
And put together the overlay:
// Ref: https://github.com/torvalds/linux/blob/v5.10/Documentation/devicetree/bindings/input/ilitek%2Cili2xxx.txt
/dts-v1/;
/plugin/;
/ {
overlay-name = "ILI2511 I2C Touch Overlay";
compatible = "nvidia,p3768-0000+p3767-0003";
fragment@0 {
target = <&i2c8>;
__overlay__ {
#address-cells = <1>;
#size-cells = <0>;
status = "okay";
ili251x: ili251x@41 {
compatible = "ilitek,ili251x";
reg = <0x41>;
interrupt-parent = <&gpio>;
interrupts = <470 2>; // gpio-470 (PY.000), 2: IRQ_TYPE_EDGE_FALLING
reset-gpios = <&gpio 474 0>; // gpio-474 (PY.04), 0: GPIO_ACTIVE_LOW ????
touchscreen-size-x = <16384>;
touchscreen-size-y = <9600>;
};
};
};
};
Like I did with the quick test overlay, I compile it and try to merge it with the base DTB:
dtc -I dts -O dtb ilitek251x-overlay.dts -o ilitek251x-overlay.dtb
This compiles fine, no errors.
$ fdtoverlay -i kernel_tegra234-p3767-0003-p3768-0000-a0-user-custom.dtb -o custom-board-v1.dtb version-overlay.dtb ilitek251x-overlay.dtb
This fails with:
Failed to apply 'ilitek251x-overlay.dtb': FDT_ERR_NOTFOUND
I am guessing it has something to do with how I am addressing things inside the overlay, but I am a bit lost.
Pointers/comments much appreciated.
kernel_tegra234-p3767-0003-p3768-0000-a0-user-custom.zip (54.1 KB) attached, in case it is helpful.
Thanks.