[PATCH v3 1/2] dt-bindings: input: Goodix GT7986U SPI HID Touchscreen

From: Charles Wang
Date: Fri Nov 08 2024 - 07:03:50 EST


The Goodix GT7986U touch controller report touch data according to the
HID protocol through the SPI bus. However, it is incompatible with
Microsoft's HID-over-SPI protocol.

NOTE: these bindings are distinct from the bindings used with the
GT7986U when the chip is running I2C firmware. For some background,
see discussion on the mailing lists in the thread:

https://lore.kernel.org/r/20241018020815.3098263-2-charles.goodix@xxxxxxxxx

Signed-off-by: Charles Wang <charles.goodix@xxxxxxxxx>
---
.../bindings/input/goodix,gt7986u-spifw.yaml | 75 +++++++++++++++++++
1 file changed, 75 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/goodix,gt7986u-spifw.yaml

diff --git a/Documentation/devicetree/bindings/input/goodix,gt7986u-spifw.yaml b/Documentation/devicetree/bindings/input/goodix,gt7986u-spifw.yaml
new file mode 100644
index 000000000..8105b9ce2
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/goodix,gt7986u-spifw.yaml
@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/goodix,gt7986u-spifw.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Goodix GT7986U SPI HID Touchscreen
+
+maintainers:
+ - Charles Wang <charles.goodix@xxxxxxxxx>
+
+description: Supports the Goodix GT7986U touchscreen.
+ This touch controller reports data packaged according to the HID protocol
+ over the SPI bus, but it is incompatible with Microsoft's HID-over-SPI protocol.
+
+ NOTE: these bindings are distinct from the bindings used with the
+ GT7986U when the chip is running I2C firmware. This is because there's
+ not a single device that talks over both I2C and SPI but rather
+ distinct touchscreens that happen to be built with the same ASIC but
+ that are distinct products running distinct firmware.
+
+allOf:
+ - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+ compatible:
+ enum:
+ - goodix,gt7986u-spifw
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ maxItems: 1
+
+ reset-gpios:
+ maxItems: 1
+
+ goodix,hid-report-addr:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ The register address for retrieving HID report data.
+
+ spi-max-frequency: true
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - reset-gpios
+ - goodix,hid-report-addr
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+ #include <dt-bindings/gpio/gpio.h>
+
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ touchscreen@0 {
+ compatible = "goodix,gt7986u-spifw";
+ reg = <0>;
+ interrupt-parent = <&gpio>;
+ interrupts = <25 IRQ_TYPE_LEVEL_LOW>;
+ reset-gpios = <&gpio1 1 GPIO_ACTIVE_LOW>;
+ spi-max-frequency = <10000000>;
+ goodix,hid-report-addr = <0x22c8c>;
+ };
+ };
+
+...
--
2.43.0