Device tree source file for FT5206

[bphan]

I'm doing a project that is to integrate touch panel FT5206 to Raspberry pi 3B+ but I don't know how to write the device tree souce file for this chip. Can anyone help me?

[6by9]

There's already edt-ft5406.
The driver does nothing different if you give it the FT5206 compatible, so you may as well just invoke it as is (dtoverlay=edt-ft5406).

It does assume the touch controller is connected to i2c_csi_dsi (aka i2c-10) as it is used as part of the Raspberry Pi 7" panel. If you look at the i2c-fan or i2c-rtc overlays you'll see how to add an override to change the i2c bus it is connected to.

[bphan]

I know the problem you said, that is to add dtoverlay=edt-ft5406 in file config.txt. I have tried but not succeeded because I don't know how to plug the pin correctly.
Have you succeeded in using edt-5406 for FT5206 screen?

[6by9]

I know the problem you said, that is to add dtoverlay=edt-ft5406 in file config.ext. I have tried but not succeeded because I don't know how to plug the pin correctly.
Have you succeeded in using edt-5406 for FT5206 screen?

I haven't used an FT5206, but we do use the FT5406 which is the same chip but with more lines for larger displays - https://www.displayfuture.com/Display/d ... FT5x06.pdf

For the Pi display, SDA and SCL go to the I2C bus on the 15pin camera and display connectors, and reset comes from a microcontroller on the display board, but you may get away with just tying it high (3V3).

[bphan]

I haven't used an FT5206, but we do use the FT5406 which is the same chip but with more lines for larger displays - https://www.displayfuture.com/Display/d ... FT5x06.pdf

For the Pi display, SDA and SCL go to the I2C bus on the 15pin camera and display connectors, and reset comes from a microcontroller on the display board, but you may get away with just tying it high (3V3).

You made with FT5406, so did it need only add dtoverlay=edt-ft5406 to the file config.txt?
Did you have to modify any information in file edt-ft5406-ovelays.dts of kernel?

[6by9]

I haven't used an FT5206, but we do use the FT5406 which is the same chip but with more lines for larger displays - https://www.displayfuture.com/Display/d ... FT5x06.pdf

For the Pi display, SDA and SCL go to the I2C bus on the 15pin camera and display connectors, and reset comes from a microcontroller on the display board, but you may get away with just tying it high (3V3).

You made with FT5406, so did it need only add dtoverlay=edt-ft5406 to the file config.txt?
Did you have to modify any information in file edt-ft5406-ovelays.dts of kernel?

If you load "dtoverlay=vc4-kms-dsi-7inch", then it configures the panel, DSI to DPI bridge, display pipeline, regulator/backlight driver, and edt-ft5406.

Both edt-ft5406 and https://github.com/raspberrypi/linux/bl ... verlay.dts have "#include "edt-ft5406.dtsi" which is the small fragment to configure the touch controller.
vc4-kms-dsi-7inch-overlay.dts does add information about the regulator and reset gpio to the ft5406 definition.

[bphan]

If you load "dtoverlay=vc4-kms-dsi-7inch", then it configures the panel, DSI to DPI bridge, display pipeline, regulator/backlight driver, and edt-ft5406.

Both edt-ft5406 and https://github.com/raspberrypi/linux/bl ... verlay.dts have "#include "edt-ft5406.dtsi" which is the small fragment to configure the touch controller.
vc4-kms-dsi-7inch-overlay.dts does add information about the regulator and reset gpio to the ft5406 definition.

In term of hardware, how many pins did you use for FT5406?
For my FT5206, it has 6 pin VDD, SDA, SCL, INT, GND and RST.

[6by9]

In term of hardware, how many pins did you use for FT5406?
For my FT5206, it has 6 pin VDD, SDA, SCL, INT, GND and RST.

VDD goes to 3.3V
GND goes to GND
SDA and SCL go to the relevant SDA and SCL of your I2C bus.
RST connects to another GPIO and you need to add that configuration to the overlay, or as I've said previously you may be able to just connect it to 3.3V.
INT can be left disconnected and the driver will poll the touch controller. Otherwise you need to connect it to a GPIO and add it to the overlay.

[bphan]

VDD goes to 3.3V
GND goes to GND
SDA and SCL go to the relevant SDA and SCL of your I2C bus.
RST connects to another GPIO and you need to add that configuration to the overlay, or as I've said previously you may be able to just connect it to 3.3V.
INT can be left disconnected and the driver will poll the touch controller. Otherwise you need to connect it to a GPIO and add it to the overlay.

In https://github.com/raspberrypi/linux/bl ... verlay.dts file. What is the address reg = <0x45> used for?
The address of FT5206 is 0x38, so do I have to change this address or not?

[6by9]

VDD goes to 3.3V
GND goes to GND
SDA and SCL go to the relevant SDA and SCL of your I2C bus.
RST connects to another GPIO and you need to add that configuration to the overlay, or as I've said previously you may be able to just connect it to 3.3V.
INT can be left disconnected and the driver will poll the touch controller. Otherwise you need to connect it to a GPIO and add it to the overlay.

In https://github.com/raspberrypi/linux/bl ... verlay.dts file. What is the address reg = <0x45> used for?
The address of FT5206 is 0x38, so do I have to change this address or not?

Look at the compatible string it uses

Code: Select all

compatible = "raspberrypi,7inch-touchscreen-panel-regulator";

https://github.com/raspberrypi/linux/bl ... tor.c#L376
and my comment earlier

For the Pi display, SDA and SCL go to the I2C bus on the 15pin camera and display connectors, and reset comes from a microcontroller on the display board, but you may get away with just tying it high (3V3).

[bphan]

In term of hardware, how many pins did you use for FT5406?
For my FT5206, it has 6 pin VDD, SDA, SCL, INT, GND and RST.

VDD goes to 3.3V
GND goes to GND
SDA and SCL go to the relevant SDA and SCL of your I2C bus.
RST connects to another GPIO and you need to add that configuration to the overlay, or as I've said previously you may be able to just connect it to 3.3V.
INT can be left disconnected and the driver will poll the touch controller. Otherwise you need to connect it to a GPIO and add it to the overlay.

I did like what you said but it still did not work. What must I do to check ?

[6by9]

I did like what you said but it still did not work. What must I do to check ?

It sounds like you've bitten off more than you can chew as you haven't apparently done any basic level diagnostics.
- Does it respond to i2cdetect?
- Have you checked the kernel logs for any messages?
- Have you checked /sys/kernel/debug/devices_deferred to ensure it isn't waiting for some additional resources?
- Have you attached a logic analyser or oscilloscope to the lines to see what is going on?
- Which kernel version are you running?

Sorry, but I'm not going to hand hold someone through bringing up a device that is known to work if they haven't got the ingenuity to attempt the basics for themselves.

[bphan]

I did like what you said but it still did not work. What must I do to check ?

It sounds like you've bitten off more than you can chew as you haven't apparently done any basic level diagnostics.
- Does it respond to i2cdetect?
- Have you checked the kernel logs for any messages?
- Have you checked /sys/kernel/debug/devices_deferred to ensure it isn't waiting for some additional resources?
- Have you attached a logic analyser or oscilloscope to the lines to see what is going on?
- Which kernel version are you running?

Sorry, but I'm not going to hand hold someone through bringing up a device that is known to work if they haven't got the ingenuity to attempt the basics for themselves.

I'm so sorry for questionning you a lot but I'm only an intern.

- I checked with i2cdetect and it responded with address 38
- When I checked with kernel logs and I found the ft5x06 like these messages, what do they mean?
[ 9.109177] edt_ft5x06 10-0038: supply vcc not found, using dummy regulator
[ 9.109590] edt_ft5x06 10-0038: supply iovcc not found, using dummy regulator
[ 9.116560] edt_ft5x06 10-0038: touchscreen probe failed
[ 9.116996] edt_ft5x06: probre of 10-0038 failed with error -121

- I found nothing in /sys/kernel/debug/devices_deferred
- The kernel version I'm using is rpi-5.14

[6by9]

I'm so sorry for questionning you a lot but I'm only an intern.

For a company to drop a project on an intern with no support is pretty unfair. Is there no one at the company who can offer basic assistance?

- I checked with i2cdetect and it responded with address 38
- When I checked with kernel logs and I found the ft5x06 like these messages, what do they mean?
[ 9.109177] edt_ft5x06 10-0038: supply vcc not found, using dummy regulator
[ 9.109590] edt_ft5x06 10-0038: supply iovcc not found, using dummy regulator
[ 9.116560] edt_ft5x06 10-0038: touchscreen probe failed
[ 9.116996] edt_ft5x06: probre of 10-0038 failed with error -121

Now we're getting somewhere.
Not finding regulators is fine - the supply rails for the touch controller aren't controlled, and the kernel uses a dummy regulator to cover it.

Look at the source and you'll see the "edt_ft5x06 10-0038: touchscreen probe failed" message comes when edt_ft5x06_ts_identify fails - https://github.com/raspberrypi/linux/bl ... 06.c#L1313
-121 is -EREMOTEIO, which for I2C means that the device didn't ACK some part of the transaction.

The 10-0038 means it is trying to load the device with i2c-10 and address 0x38. As previously covered, i2c-10 is the I2C bus on the camera and display connectors. Is that where you have connected the touch controller? If not you need to update the dtoverlay.

How have you actually connected up the touch controller? Full wiring details please.

- I found nothing in /sys/kernel/debug/devices_deferred
- The kernel version I'm using is rpi-5.14

rpi-5.14.y is pretty old (last updated Nov 2021), and unsupported from both mainline (as it's not an LTS release or current) and Raspberry Pi.
rpi-6.1.y is the current branch, and being an LTS release is projected to be maintained until Dec 2026 (see https://www.kernel.org/releases.html). It should be considered the preferred branch unless there is some VERY good reason to do otherwise.

[bphan]

The 10-0038 means it is trying to load the device with i2c-10 and address 0x38. As previously covered, i2c-10 is the I2C bus on the camera and display connectors. Is that where you have connected the touch controller? If not you need to update the dtoverlay.
How have you actually connected up the touch controller? Full wiring details please.

I have connected up the touch controller like that
FT5206 -> Rpi
VDD --------> 1 (3.3V)
SDA --------> 3 (GPIO2, I2C1 SDA)
SCL ---------> 5 (GPIO3, I2C1 SCL)
INT --------> no connection
GND --------> 9 (Ground)
RST ---------> 17 (3.3V)

[6by9]

I have connected up the touch controller like that
FT5206 -> Rpi
VDD --------> 1 (3.3V)
SDA --------> 3 (GPIO2, I2C1 SDA)
SCL ---------> 5 (GPIO3, I2C1 SCL)
INT --------> no connection
GND --------> 9 (Ground)
RST ---------> 17 (3.3V)

So you've connected to i2c-1, but not told the kernel to look at that i2c bus.

I wouldn't normally do this, but https://github.com/raspberrypi/linux/pull/5504 makes the required changes to the overlay to allow you to choose which I2C bus to select.
Once CI has done the business (takes about an hour), you should be able to use "sudo rpi-update pulls/5504" to update the kernel to get that change. You should then be able to use "dtoverlay=edt-ft5406,i2c1" to switch to i2c-1.

[bphan]

So you've connected to i2c-1, but not told the kernel to look at that i2c bus.
I wouldn't normally do this, but https://github.com/raspberrypi/linux/pull/5504 makes the required changes to the overlay to allow you to choose which I2C bus to select.
Once CI has done the business (takes about an hour), you should be able to use "sudo rpi-update pulls/5504" to update the kernel to get that change. You should then be able to use "dtoverlay=edt-ft5406,i2c1" to switch to i2c-1.

In config.txt file, I also wrote "dtoverlay=edt-ft5406,i2c1,pins_2_3".
"sudo rpi-update pulls/5504" for this command, where I can update? in the raspberry after building and compiling the kernel or when building image in other computer?

**Update:
After I have made "sudo rpi-update pulls/5504", I check dmesg | grep edt_ft5x06, it still displayed like that:
edt_ft5x06 10-0038: supply vcc not found, using dummy regulator
edt_ft5x06 10-0038: supply iovcc not found, using dummy regulator
edt_ft5x06 10-0038: touchscreen probe failed
edt_ft5x06: probre of 10-0038 failed with error -121

[6by9]

In config.txt file, I also wrote "dtoverlay=edt-ft5406,i2c1,pins_2_3".
"sudo rpi-update pulls/5504" for this command, where I can update? in the raspberry after building and compiling the kernel or when building image in other computer?

**Update:
After I have make "sudo rpi-update pulls/5504", I check dmesg | grep edt_ft5x06, it still displayed like that:
edt_ft5x06 10-0038: supply vcc not found, using dummy regulator
edt_ft5x06 10-0038: supply iovcc not found, using dummy regulator
edt_ft5x06 10-0038: touchscreen probe failed
edt_ft5x06: probre of 10-0038 failed with error -121

Why invent you own parameters in "pins_2_3"?
Were there any errors reported by rpi-update? Did you reboot?
What kernel version does your system now report it's running? ("uname -a")
What's the timestamp on /boot/overlays/edt-ft5406.dtbo?
You can check whether the firmware has had issues in applying device tree commands using "sudo vclog -m", with the option to enable extra debugging by adding "dtdebug=1" to /boot/config.txt.

Sorry, but this is as bad as pulling teeth. If you can't or won't do the basic diagnostics, then please find someone who is capable of doing such.

[bphan]

Why invent you own parameters in "pins_2_3"?
Were there any errors reported by rpi-update? Did you reboot?
What kernel version does your system now report it's running? ("uname -a")
What's the timestamp on /boot/overlays/edt-ft5406.dtbo?
You can check whether the firmware has had issues in applying device tree commands using "sudo vclog -m", with the option to enable extra debugging by adding "dtdebug=1" to /boot/config.txt.

Sorry, but this is as bad as pulling teeth. If you can't or won't do the basic diagnostics, then please find someone who is capable of doing such.

- The parameters pins_2_3 is for GPIO and 3
- There were no errors reported when updating rpi, I also rebooted
- As I said before, I'm using Linux kernel 5.14 because my rpi is rpi3 B+, I installed linux 6.1 or any other later version, it could not run. I will find a rpi with more recent version to try

[rpdom]

- As I said before, I'm using Linux kernel 5.14 because my rpi is rpi3 B+, I installed linux 6.1 or any other later version, it could not run.

Something is up with your setup then.

Code: Select all

notpi@raspi4:~ $ grep Model /proc/cpuinfo 
Model		: Raspberry Pi 3 Model B Plus Rev 1.3
notpi@raspi4:~ $ uname -r
6.1.21-v8+

Running Raspberry Pi OS Bullseye 64-bit.

[bphan]

Something is up with your setup then.

Code: Select all

notpi@raspi4:~ $ grep Model /proc/cpuinfo 
Model		: Raspberry Pi 3 Model B Plus Rev 1.3
notpi@raspi4:~ $ uname -r
6.1.21-v8+

Running Raspberry Pi OS Bullseye 64-bit.

Hello, how did you install rpi-6.1 sur RPI 3 B+?
I installed thanks to this link https://www.raspberrypi.com/documentati ... ernel.html

[rpdom]

Hello, how did you install rpi-6.1 sur RPI 3 B+?

It's the standard kernel on the Bullseye release. I just ran sudo apt update and sudp apt full-upgrade to get the latest released version.

It's in the raspberrypi-kernel package.

Code: Select all

notpi@raspi4:~ $ apt policy raspberrypi-kernel
raspberrypi-kernel:
  Installed: 1:1.20230405-1
  Candidate: 1:1.20230405-1
  Version table:
 *** 1:1.20230405-1 500
        500 http://archive.raspberrypi.org/debian bullseye/main arm64 Packages
        100 /var/lib/dpkg/status

[bphan]

Hello, how did you install rpi-6.1 sur RPI 3 B+?

It's the standard kernel on the Bullseye release. I just ran sudo apt update and sudp apt full-upgrade to get the latest released version.

It's in the raspberrypi-kernel package.

Code: Select all

notpi@raspi4:~ $ apt policy raspberrypi-kernel
raspberrypi-kernel:
  Installed: 1:1.20230405-1
  Candidate: 1:1.20230405-1
  Version table:
 *** 1:1.20230405-1 500
        500 http://archive.raspberrypi.org/debian bullseye/main arm64 Packages
        100 /var/lib/dpkg/status

I have run sudo apt update and sudp apt full-upgrade but it still kept the old version, it did not change anything.
Which original version did you install before updating?

[6by9]

You've still not actually posted what "uname -a" returns.

5.14 has never been released through apt. Have you built your own kernel and added a "kernel=... " line to config.txt?

Take a fresh SD card, and flash it with a Raspberry Pi OS (doesn't really matter whether 32 or 64bit on a Pi3).
Update it using "sudo apt update" "sudo apt dist-upgrade".
Reboot.
Tell us what "uname -a" reports.
Run "sudo rpi-update pulls/5504". Report any errors.
Reboot.
Tell us what "uname -a" reports.

Assuming you're now getting 6.1.32, try adding "dtoverlay=edt-ft5406,i2c1" to /boot/config.txt and rebooting.

[bphan]

Have you built your own kernel and added a "kernel=... " line to config.txt?

Yes, before up to now I have built my kernel by this way https://www.raspberrypi.com/documentati ... ernel.html so that I can activate the EDT-FT5x06

Device Drivers -->
........Input device support -->
...............-*- Generic input layer (needed for keyboard, mouse, ...)
...............*** Userland interfaces ***
............... <*> Event interface
............... < > Event debugging
...............*** Input Device Drivers ***
............... [ ] Joysticks/Gamepads --->
............... [ ] Tablets --->
............... [*] Touchscreens --->
.............................................<*> EDT FocalTech FT5x06 I2C Touchscreen support
A big problem here is that when I build my kernel by this way, it appeared an error "No wireless interfaces found"

Take a fresh SD card, and flash it with a Raspberry Pi OS (doesn't really matter whether 32 or 64bit on a Pi3).
Update it using "sudo apt update" "sudo apt dist-upgrade".
Reboot.
Tell us what "uname -a" reports.
Run "sudo rpi-update pulls/5504". Report any errors.
Reboot.
Tell us what "uname -a" reports.
Assuming you're now getting 6.1.32, try adding "dtoverlay=edt-ft5406,i2c1" to /boot/config.txt and rebooting.

I updated successfully rpi full-upgrade and pulls/5504.
I have found some problem:
- I ran "uname -a", it is 6.1.21-v8+, I also added "dtoverlay=edt-ft5406,i2c1" to /boot/config.txt and rebooted.
- I ran "dmesg | grep edt" or "dmesg | grep ft5x06", it displayed like that:

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bphan@raspberrypi:~ $ dmesg | grep edt
[   16.540022] edt_ft5x06 1-0038: supply vcc not found, using dummy regulator
[   16.573811] edt_ft5x06 1-0038: supply iovcc not found, using dummy regulator
[   16.743536] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   35.395485] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   35.419491] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   35.443480] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   35.467544] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   72.407487] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   72.431494] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   72.455479] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   72.479486] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   72.503483] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   72.527484] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   72.551482] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   72.575389] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   72.599390] edt_ft5x06 1-0038: Unable to fetch data, error: -5
[   72.623389] edt_ft5x06 1-0038: Unable to fetch data, error: -5

- I tried another time and it displayed:

Code: Select all

bphan@raspberrypi:~ $ dmesg | grep edt
[   15.749246] edt_ft5x06 1-0038: supply vcc not found, using dummy regulator
[   15.750079] edt_ft5x06 1-0038: supply iovcc not found, using dummy regulator
[   15.751168] edt_ft5x06 1-0038: Unable to fetch data, error: -5