Add touchscreen support to device tree

[hansemro]

Resources:

• https://github.com/hansemro/kernel_omap_otter-common/blob/84763bbf0a9138cb0ba7b42411cd8d0405c1c684/arch/arm/mach-omap2/board-4430kc1-tablet.c#L592-L596
• https://github.com/hansemro/kernel_omap_otter-common/blob/84763bbf0a9138cb0ba7b42411cd8d0405c1c684/arch/arm/mach-omap2/board-4430kc1-tablet.c#L957-L977
• https://github.com/hansemro/kernel_omap_otter-common/blob/p-android-omap-3.4/drivers/input/touchscreen/ili210x.c
• https://github.com/hansemro/kernel_omap_otter-common/blob/p-android-omap-3.4/drivers/input/touchscreen/ilitek.c
• Documentation/devicetree/bindings/input/ilitek,ili2xxx.txt
• https://github.com/torvalds/linux/blob/master/drivers/input/touchscreen/ili210x.c

ILITEK 2107QS001K touchscreen controller:

• tracks only two fingers.
• poll period = 2 ms
• i2c-2
• VAUX3 3V voltage regulator
• GPIO 18: touch IRQ reset OMAP4_TOUCH_RESET_GPIO
• GPIO 35: touch IRQ 1
• GPIO 36: touch IRQ 2 (unused?)
• GPIO 104: ILITEK_TS_RESET (from ilitek.c)

[hansemro]

arch/arm/boot/dts/omap4-kc1.dts

&i2c2 {
	...
	touchscreen@41 {
		compatible = "ilitek,ili210x";
		reg = <0x41>;
		interrupt-parent = <&gpio2>;
		interrupts = <3 IRQ_TYPE_EDGE_FALLING /* gpio_35 TOUCH_IRQ_1 */
			4 IRQ_TYPE_EDGE_FALLING /* gpio_36 TOUCH_IRQ_2 */
			>;
		reset-gpios = <&gpio1 18 GPIO_ACTIVE_LOW>; /* gpio_18; configuration uncertain */
	};
	...
};

[mj-sakellaropoulos]

Change compatible to "ilitek,ili210x" and the driver will load.

There are some errors though:

~ # ls /dev/input/
by-path  event0
~ # dmesg | grep ili
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 129412
[    4.222412] i2c-core: driver [ili210x_i2c] registered
[    8.899566] ili210x_i2c 1-0041: probe
[    8.899566] ili210x_i2c 1-0041: GPIO lookup for consumer reset
[    8.909698] ili210x_i2c 1-0041: using device tree for GPIO lookup
[    9.083251] i2c i2c-1: client [ili210x] registered with bus id 1-0041
[   10.416076] ili210x_i2c 1-0041: ili210x_read_reg failed: -16
[   10.429809] ili210x_i2c 1-0041: Unable to get touch data: -16
[   11.466674] ili210x_i2c 1-0041: ili210x_read_reg failed: -16
[   11.472686] ili210x_i2c 1-0041: Unable to get touch data: -16

xinput:

~ # xinput
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ ILI210x Touchscreen                       id=6    [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]

And I can confirm that it is not working under X11

xinput --map-to-output 6 "DPI-1"

[hansemro]

https://github.com/hansemro/kernel_omap_otter-common/blob/84763bbf0a9138cb0ba7b42411cd8d0405c1c684/drivers/input/touchscreen/ilitek.c#L914

Looks like VAUX3 regulator is for touchscreen

[hansemro]

@mj-sakellaropoulos Can you replace/add GPIO 104 for reset?

reset-gpios = <&gpio1 18 GPIO_ACTIVE_LOW
	&gpio3 8 GPIO_ACTIVE_LOW
	>;

[hansemro]

I am not totally convinced that the reset is active low btw. It just happened to be in one of the ilitek examples.

[mj-sakellaropoulos]

I will try that too. I set VAUX3 to always on but it's still getting disabled
As soon as VAUX3 is disabled we get ilitek errors

[   27.658447] g_cdc gadget: acm ttyGS0 serial state 0000
[   27.659027] gs_close: ttyGS0 (22c130d3,70c60c71) done!
[   27.659545] gs_open: start ttyGS0
[   27.659545] gs_open: ttyGS0 (22c130d3,a90e9dc6)
[   27.682830] g_cdc gadget: acm ttyGS0 serial state 0003
[   35.708587] g_cdc gadget: acm ttyGS0 req21.22 v0000 i0002 l0
[   35.709899] g_cdc gadget: acm ttyGS0 req21.22 v0003 i0002 l0
[   35.710388] g_cdc gadget: acm ttyGS0 req21.20 v0000 i0002 l7
[   35.710906] g_cdc gadget: acm ttyGS0 req21.22 v0000 i0002 l0
[   39.517517] VAUX3_6030: disabling
[   39.525329] VDAC: disabling
[   39.528411] VANA: disabling
[   39.529357] vwl1271: disabling
[   40.562103] ili210x_i2c 1-0041: ili210x_read_reg failed: -16
[   40.562194] ili210x_i2c 1-0041: Unable to get touch data: -16
[   41.591918] ili210x_i2c 1-0041: ili210x_read_reg failed: -16
[   41.591918] ili210x_i2c 1-0041: Unable to get touch data: -16
[   42.632110] ili210x_i2c 1-0041: ili210x_read_reg failed: -16

OK I managed to set VAUX3 to enabled for real this time, no more ilitek errors

[    6.038635] VAUX3_6030: 1000 <--> 3000 mV at 1200 mV, enabled

[hansemro]

Can you cat the new input device and get touch data?

Also, set vaux3 to 3V

&vaux3 {
	regulator-min-microvolt = <3000000>;
	regulator-max-microvolt = <3000000>;
};

[mj-sakellaropoulos]

Something is stopping the driver probe

I can see an entry in /sys/class/input/input0

but no /dev/input

there are no errors

Also, set vaux3 to 3V

Oh the 1v would explain it

[mj-sakellaropoulos]

Ok, VAUX3 set to 3v0, and reset GPIO is as described above

[    6.050262] VAUX3_6030: Bringing 1200000uV into 3000000-3000000uV
[    6.060516] VAUX3_6030: ramp_delay not set
[    6.068267] VAUX3_6030: 3000 mV, enabled

Nothing in /dev/input, no errors and ili210 driver is not probing
ilitek is gone from xinput list:

/ # xinput
⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
/ #

/ # dmesg | grep i2c-1
[    6.264434] i2c i2c-1: GPIO lookup for consumer scl
[    6.269592] i2c i2c-1: using device tree for GPIO lookup
[    6.303222] i2c i2c-1: using lookup tables for GPIO lookup
[    6.309020] i2c i2c-1: No GPIO consumer scl found
[    6.314086] i2c i2c-1: GPIO lookup for consumer sda
[    6.314086] i2c i2c-1: using device tree for GPIO lookup
[    6.352783] i2c i2c-1: using lookup tables for GPIO lookup
[    6.358581] i2c i2c-1: No GPIO consumer sda found
[    6.524475] input: ILI210x Touchscreen as /devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041/input/input0
/ # dmesg | grep ili2
[    6.366333] ili210x_i2c 1-0041: GPIO lookup for consumer reset
[    6.372528] ili210x_i2c 1-0041: using device tree for GPIO lookup
/ #

[mj-sakellaropoulos]

The issue is that the probe function is never executed (I used to see this printk), which is strange because it was working before (? maybe that was my imagination, either way - probe is not working)

Also the way dev_err works, I would have seen it

For instance, this is the only occurence of "input" in the dmesg

[    6.524475] input: ILI210x Touchscreen as /devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041/input/input0

Afaik, probe function is executed by the kernel once it finds the matching compatible = ilitek,ili210x in the devicetree, it looks up what driver is needed for it and the calls the probe function specified by this

[mj-sakellaropoulos]

Could have something to do with udev or other userspace issues at this point since there are no errors.

/ # udevadm info -q all -p /sys/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041/input/input0
P: /devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041/input/input0
E: ABS=2608000 3
E: DEVPATH=/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041/input/input0
E: EV=b
E: ID_INPUT=1
E: ID_INPUT_TOUCHSCREEN=1
E: ID_PATH=platform-48072000.i2c
E: ID_PATH_TAG=platform-48072000_i2c
E: KEY=400 0 0 0 0 0 0 0 0 0 0
E: MODALIAS=input:b0018v0000p0000e0000-e0,1,3,k14A,ra0,1,2F,35,36,39,mlsfw
E: NAME="ILI210x Touchscreen"
E: PRODUCT=18/0/0/0
E: PROP=2
E: SUBSYSTEM=input
E: USEC_INITIALIZED=14343343

udeven info recursive

/ # udevadm info -q all -a -p /sys/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041/input/input0

Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041/input/input0':
    KERNEL=="input0"
    SUBSYSTEM=="input"
    DRIVER==""
    ATTR{uniq}==""
    ATTR{properties}=="2"
    ATTR{phys}==""
    ATTR{inhibited}=="0"
    ATTR{name}=="ILI210x Touchscreen"

  looking at parent device '/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041':
    KERNELS=="1-0041"
    SUBSYSTEMS=="i2c"
    DRIVERS=="ili210x_i2c"
    ATTRS{name}=="ili210x"

  looking at parent device '/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1':
    KERNELS=="i2c-1"
    SUBSYSTEMS=="i2c"
    DRIVERS==""
    ATTRS{name}=="OMAP I2C adapter"

  looking at parent device '/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c':
    KERNELS=="48072000.i2c"
    SUBSYSTEMS=="platform"
    DRIVERS=="omap_i2c"
    ATTRS{driver_override}=="(null)"

  looking at parent device '/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module':
    KERNELS=="48072000.target-module"
    SUBSYSTEMS=="platform"
    DRIVERS=="ti-sysc"
    ATTRS{driver_override}=="(null)"

  looking at parent device '/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0':
    KERNELS=="48000000.interconnect:segment@0"
    SUBSYSTEMS=="platform"
    DRIVERS=="simple-pm-bus"
    ATTRS{driver_override}=="(null)"

  looking at parent device '/devices/platform/ocp/48000000.interconnect':
    KERNELS=="48000000.interconnect"
    SUBSYSTEMS=="platform"
    DRIVERS=="simple-pm-bus"
    ATTRS{driver_override}=="(null)"

  looking at parent device '/devices/platform/ocp':
    KERNELS=="ocp"
    SUBSYSTEMS=="platform"
    DRIVERS=="simple-pm-bus"
    ATTRS{driver_override}=="(null)"

  looking at parent device '/devices/platform':
    KERNELS=="platform"
    SUBSYSTEMS==""
    DRIVERS==""

/ #

udevadm test

/ # udevadm test /sys/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041/input/input0
calling: test
version 3.2.10
This program is for debugging only, it does not run any program
specified by a RUN key. It may show incorrect results, because
some values may be different, or not available at a simulation run.

/etc/udev/hwdb.bin does not exist, please run udevadm hwdb --update
Load module index
timestamp of '/etc/udev/rules.d' changed
Reading rules file: /usr/lib/udev/rules.d/10-dm.rules
Reading rules file: /usr/lib/udev/rules.d/11-dm-lvm.rules
Reading rules file: /usr/lib/udev/rules.d/11-dm-mpath.rules
Reading rules file: /usr/lib/udev/rules.d/11-dm-parts.rules
Reading rules file: /usr/lib/udev/rules.d/13-dm-disk.rules
Reading rules file: /etc/udev/rules.d/50-firmware.rules
Reading rules file: /lib/udev/rules.d/50-udev-default.rules
Reading rules file: /usr/lib/udev/rules.d/56-multipath.rules
Reading rules file: /lib/udev/rules.d/60-block.rules
Reading rules file: /lib/udev/rules.d/60-cdrom_id.rules
Reading rules file: /lib/udev/rules.d/60-drm.rules
Reading rules file: /lib/udev/rules.d/60-evdev.rules
Reading rules file: /lib/udev/rules.d/60-input-id.rules
Reading rules file: /lib/udev/rules.d/60-persistent-alsa.rules
Reading rules file: /lib/udev/rules.d/60-persistent-input.rules
Reading rules file: /lib/udev/rules.d/60-persistent-storage-tape.rules
Reading rules file: /lib/udev/rules.d/60-persistent-storage.rules
Reading rules file: /lib/udev/rules.d/60-persistent-v4l.rules
Reading rules file: /lib/udev/rules.d/60-sensor.rules
Reading rules file: /lib/udev/rules.d/60-serial.rules
Reading rules file: /run/udev/rules.d/61-dev-root-link.rules
Reading rules file: /lib/udev/rules.d/64-btrfs.rules
Reading rules file: /usr/lib/udev/rules.d/66-kpartx.rules
Reading rules file: /usr/lib/udev/rules.d/68-del-part-nodes.rules
Reading rules file: /lib/udev/rules.d/70-joystick.rules
Reading rules file: /lib/udev/rules.d/70-mouse.rules
Reading rules file: /lib/udev/rules.d/70-touchpad.rules
Reading rules file: /lib/udev/rules.d/75-net-description.rules
Reading rules file: /lib/udev/rules.d/75-probe_mtd.rules
Reading rules file: /lib/udev/rules.d/78-sound-card.rules
Reading rules file: /lib/udev/rules.d/80-drivers.rules
Reading rules file: /usr/lib/udev/rules.d/80-libinput-device-groups.rules
Reading rules file: /lib/udev/rules.d/84-nm-drivers.rules
Reading rules file: /lib/udev/rules.d/85-nm-unmanaged.rules
Reading rules file: /usr/lib/udev/rules.d/90-libinput-fuzz-override.rules
Reading rules file: /lib/udev/rules.d/90-nm-thunderbolt.rules
Reading rules file: /usr/lib/udev/rules.d/95-dm-notify.rules
Reading rules file: /lib/udev/rules.d/95-upower-csr.rules
Reading rules file: /lib/udev/rules.d/95-upower-hid.rules
Reading rules file: /lib/udev/rules.d/95-upower-hidpp.rules
Reading rules file: /lib/udev/rules.d/95-upower-wup.rules
Reading rules file: /usr/lib/udev/rules.d/99-triggerhappy.rules
rules contain 49152 bytes tokens (4096 * 12 bytes), 13776 bytes strings
2324 strings (28885 bytes), 1606 de-duplicated (15828 bytes), 719 trie nodes used
IMPORT builtin 'hwdb' /lib/udev/rules.d/50-udev-default.rules:14
IMPORT builtin 'hwdb' returned non-zero
IMPORT builtin 'input_id' /lib/udev/rules.d/60-input-id.rules:5
capabilities/ev raw kernel attribute: b
capabilities/abs raw kernel attribute: 2608000 3
capabilities/rel raw kernel attribute: 0
capabilities/key raw kernel attribute: 400 0 0 0 0 0 0 0 0 0 0
properties raw kernel attribute: 2
test_key: checking bit block 0 for any keys; found=0
test_key: checking bit block 32 for any keys; found=0
test_key: checking bit block 64 for any keys; found=0
test_key: checking bit block 96 for any keys; found=0
test_key: checking bit block 128 for any keys; found=0
test_key: checking bit block 160 for any keys; found=0
test_key: checking bit block 192 for any keys; found=0
test_key: checking bit block 224 for any keys; found=0
IMPORT builtin 'hwdb' /lib/udev/rules.d/60-input-id.rules:6
IMPORT builtin 'hwdb' returned non-zero
IMPORT builtin 'path_id' /lib/udev/rules.d/60-persistent-input.rules:35
RUN 'kmod load $env{MODALIAS}' /lib/udev/rules.d/80-drivers.rules:5
RUN '/usr/sbin/th-cmd --socket /var/run/thd.socket --passfd --udev' /usr/lib/udev/rules.d/99-triggerhappy.rules:4
created db file '/run/udev/data/+input:input0' for '/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041/input/input0'
ABS=2608000 3
ACTION=add
DEVPATH=/devices/platform/ocp/48000000.interconnect/48000000.interconnect:segment@0/48072000.target-module/48072000.i2c/i2c-1/1-0041/input/input0
EV=b
ID_INPUT=1
ID_INPUT_TOUCHSCREEN=1
ID_PATH=platform-48072000.i2c
ID_PATH_TAG=platform-48072000_i2c
KEY=400 0 0 0 0 0 0 0 0 0 0
MODALIAS=input:b0018v0000p0000e0000-e0,1,3,k14A,ra0,1,2F,35,36,39,mlsfw
NAME="ILI210x Touchscreen"
PRODUCT=18/0/0/0
PROP=2
SUBSYSTEM=input
USEC_INITIALIZED=14343343
run: 'kmod load input:b0018v0000p0000e0000-e0,1,3,k14A,ra0,1,2F,35,36,39,mlsfw'
run: '/usr/sbin/th-cmd --socket /var/run/thd.socket --passfd --udev'
Unload module index

[mj-sakellaropoulos]

From your 5.11.x kernel config: evdev is set to m

...
#
# Input device support
#
CONFIG_INPUT=y
# CONFIG_INPUT_LEDS is not set
# CONFIG_INPUT_FF_MEMLESS is not set
# CONFIG_INPUT_SPARSEKMAP is not set
# CONFIG_INPUT_MATRIXKMAP is not set

#
# Userland interfaces
#
CONFIG_INPUT_MOUSEDEV=m
# CONFIG_INPUT_MOUSEDEV_PSAUX is not set
CONFIG_INPUT_MOUSEDEV_SCREEN_X=1024
CONFIG_INPUT_MOUSEDEV_SCREEN_Y=600
# CONFIG_INPUT_JOYDEV is not set
CONFIG_INPUT_EVDEV=m
CONFIG_INPUT_EVBUG=m
...

But the module is not present in rootfs

I remember now, I recompiled my kernel with evdev = Y and /dev/input/... should appear

As it is right now, there is no way to modprobe evdev