Re: [PATCH v4 2/3] dt-bindings: touchscreen: Add HY46XX bindings

From: Giulio Benetti
Date: Sun Apr 11 2021 - 07:37:12 EST


On 4/8/21 10:21 PM, Rob Herring wrote:
On Wed, Apr 07, 2021 at 07:49:08PM +0200, Giulio Benetti wrote:
This adds device tree bindings for the Hycon HY46XX touchscreen series.

Signed-off-by: Giulio Benetti <giulio.benetti@xxxxxxxxxxxxxxxxxxxxxx>
---
V1->V2:
As suggested by Rob Herring:
* fixed $id: address
* added "hycon," in front of every custom property
* changed all possible property to boolean type
* removed proximity-sensor-switch property since it's not handled in driver
V2->V3:
As suggested by Jonathan Neuschäfer:
* fixed some typo
* fixed description indentation
* improved boolean properties descriptions
* improved hycon,report-speed description
V3->V4:
* fixed binding compatible string in example as suggested by Jonathan Neuschäfer
---
.../input/touchscreen/hycon,hy46xx.yaml | 120 ++++++++++++++++++
MAINTAINERS | 6 +
2 files changed, 126 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/touchscreen/hycon,hy46xx.yaml

diff --git a/Documentation/devicetree/bindings/input/touchscreen/hycon,hy46xx.yaml b/Documentation/devicetree/bindings/input/touchscreen/hycon,hy46xx.yaml
new file mode 100644
index 000000000000..8860613a12ad
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/hycon,hy46xx.yaml
@@ -0,0 +1,120 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/touchscreen/hycon,hy46xx.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Hycon HY46XX series touchscreen controller bindings
+
+description: |
+ There are 6 variants of the chip for various touch panel sizes and cover lens material
+ Glass: 0.3mm--4.0mm
+ PET/PMMA: 0.2mm--2.0mm
+ HY4613(B)-N048 < 6"
+ HY4614(B)-N068 7" .. 10.1"
+ HY4621-NS32 < 5"
+ HY4623-NS48 5.1" .. 7"
+ Glass: 0.3mm--8.0mm
+ PET/PMMA: 0.2mm--4.0mm
+ HY4633(B)-N048 < 6"
+ HY4635(B)-N048 < 7" .. 10.1"
+
+maintainers:
+ - Giulio Benetti <giulio.benetti@xxxxxxxxxxxxxxxxxxxxxx>
+
+allOf:
+ - $ref: touchscreen.yaml#
+
+properties:
+ compatible:
+ enum:
+ - hycon,hycon-hy4613
+ - hycon,hycon-hy4614
+ - hycon,hycon-hy4621
+ - hycon,hycon-hy4623
+ - hycon,hycon-hy4633
+ - hycon,hycon-hy4635

As suggested earlier, drop the 2nd 'hycon'.

Ok

+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ reset-gpios:
+ maxItems: 1
+
+ vcc-supply: true
+
+ hycon,threshold:
+ description: Allows setting the sensitivity in the range from 0 to 255.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 255
+
+ hycon,glove-enable:
+ type: boolean
+ description: Allows enabling glove setting.
+
+ hycon,report-speed:
+ description: Allows setting the report speed in Hertz.

If in Hertz, use standard unit suffix.

+ $ref: /schemas/types.yaml#/definitions/uint32

And then you can drop this.

Ok

+ minimum: 0

0Hz doesn't seem to useful?

You're right, I've also checked and with 0Hz controller correctly does nothing. I've also tried seeting 1Hz and it actually works, but at 1Hz, so I keep 1Hz as minimum.

+ maximum: 255
+
+ hycon,power-noise-enable:

hycon,noise-filter-enable

No one wants to enable power noise. :)

:-) Yeah


+ type: boolean
+ description: Allows enabling power noise filter.
+
+ hycon,filter-data:
+ description: Allows setting the filtering data before reporting touch
+ in the range from 0 to 5.

This is averaging samples? Sounds like something common perhaps.

maybe you mean touchscreen-average-samples property, but this is not the case.In datasheet they state "Before report coordinate throw away the data number, setting range:0--5" and I've tried sweep-setting it 1-5 and what I get with filter-data set to 5 is that touchscreen answers after like 0.5 seconds but keep reporting as fast as set report-speed, so to me it throws away the first samples because it considers them "bad" samples when one is first touching the panel. So I'm going to modify the description as:
description: Allows setting how many samples throw before reporting
touch in the range from 0 to 5.

+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 5
+
+ hycon,gain:
+ description: Allows setting the sensitivity distance in the range from 0 to 5.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 5
+
+ hycon,edge-offset:
+ description: Allows setting the edge compensation in the range from 0 to 16.
+ $ref: /schemas/types.yaml#/definitions/uint32
+ minimum: 0
+ maximum: 16
+
+ touchscreen-size-x: true
+ touchscreen-size-y: true
+ touchscreen-fuzz-x: true
+ touchscreen-fuzz-y: true
+ touchscreen-inverted-x: true
+ touchscreen-inverted-y: true
+ touchscreen-swapped-x-y: true
+ interrupt-controller: true
+
+additionalProperties: false
+
+required:
+ - compatible
+ - reg
+ - interrupts
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ hycon-hy4633@1c {

touchscreen@1c

Ok

+ compatible = "hycon,hycon-hy4633";
+ reg = <0x1c>;
+ interrupt-parent = <&gpio2>;
+ interrupts = <5 IRQ_TYPE_EDGE_FALLING>;
+ reset-gpios = <&gpio2 6 GPIO_ACTIVE_LOW>;
+ };
+ };
+
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index c80ad735b384..d022ff09e609 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8243,6 +8243,12 @@ S: Maintained
F: mm/hwpoison-inject.c
F: mm/memory-failure.c
+HYCON HY46XX TOUCHSCREEN SUPPORT
+M: Giulio Benetti <giulio.benetti@xxxxxxxxxxxxxxxxxxxxxx>
+L: linux-input@xxxxxxxxxxxxxxx
+S: Maintained
+F: Documentation/devicetree/bindings/input/touchscreen/hycon,hy46xx.yaml
+
HYGON PROCESSOR SUPPORT
M: Pu Wen <puwen@xxxxxxxx>
L: linux-kernel@xxxxxxxxxxxxxxx
--
2.25.1


Thank you

Best regards
--
Giulio Benetti
Benetti Engineering sas