Thread (9 messages) 9 messages, 2 authors, 2022-02-25

Re: [PATCH v4 3/6] Documentation: DT bindings for Microsoft G6 Touch Digitizer

From: Rob Herring <robh@kernel.org>
Date: 2022-02-25 14:58:39
Also in: linux-devicetree, linux-spi

On Thu, Feb 24, 2022 at 04:59:33PM -0800, Dmitry Antipov wrote:
From: Dmitry Antipov <redacted>
Please follow the conventions of the subsystem for the subject:

dt-bindings: input: ...
quoted hunk ↗ jump to hunk
Documentation describes the required and optional properties for
implementing Device Tree for a Microsoft G6 Touch Digitizer that
supports HID over SPI Protocol 1.0 specification.

Signed-off-by: Dmitry Antipov <redacted>
---
 .../input/microsoft,g6-touch-digitizer.yaml   | 105 ++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml
diff --git a/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml b/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml
new file mode 100644
index 000000000000..e516717527e9
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/microsoft,g6-touch-digitizer.yaml
@@ -0,0 +1,105 @@
+# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/input/microsoft,g6-touch-digitizer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microsoft G6 Touch Digitizer
+
+maintainers:
+  - Dmitry Antipov <dmanti@microsoft.com>
+
+description: |
+  Microsoft G6 touch digitizer is a HID over SPI device supporting HID Over SPI
+  Protocol Specification 1.0, available at
+  https://www.microsoft.com/en-us/download/details.aspx?id=103325.
+
+properties:
+  compatible:
+    oneOf:
+      - const: microsoft,g6-touch-digitizer
+      - items:
+        - const: microsoft,g6-touch-digitizer
+        - const: hid-over-spi
Why are both cases needed?

Assuming you keep the 2nd case, you will need a custom 'select' to avoid 
applying this schema to another binding using 'hid-over-spi':

select:
  properties:
    compatible:
      contains:
	const: microsoft,g6-touch-digitizer

  required:
    - compatible

+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  reset-gpios:
+    maxItems: 1
+    description:
+      GPIO specifier for the digitizer's reset pin (active low). The line must
+      be flagged with GPIO_ACTIVE_LOW.
+
+  vdd-supply:
+    description:
+      Regulator for the VDD supply voltage.
+
+  input-report-header-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      This property and the rest are described in HID Over SPI Protocol Spec 1.0
Each property needs a description and a more specific spec location.

No constraints on the values? 0 - 2^32 is valid?
+
+  input-report-body-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  output-report-address:
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  read-opcode:
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  write-opcode:
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  hid-over-spi-flags:
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  post-power-on-delay-ms:
+    description:
+      Optional time in ms required by the device after enabling its regulators
+      or powering it on, before it is ready for communication.
+
+  minimal-reset-delay-ms:
+    description:
+      Optional minimum amount of time in ms that device needs to be in reset
+      state for the reset to take effect.
These should be implied by the compatible string.
+
+required:
+  - compatible
+  - interrupts
+  - reset-gpios
It's not allowed to have reset under h/w control?
+  - vdd-supply
+  - input-report-header-address
+  - input-report-body-address
+  - output-report-address
+  - read-opcode
+  - write-opcode
+  - hid-over-spi-flags
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/gpio/gpio.h>
+    spi-hid-dev0 {
hid@0

And you'll need to define a spi bus.
+      compatible = "microsoft,g6-touch-digitizer", "hid-over-spi";
+      reg = <0>;
+      interrupts-extended = <&gpio 42 IRQ_TYPE_EDGE_FALLING>;
+      reset-gpios = <&gpio 27 GPIO_ACTIVE_LOW>;
+      vdd-supply = <&pm8350c_l3>;
+      pinctrl-names = "default";
+      pinctrl-0 = <&ts_d6_reset_assert &ts_d6_int_bias>;
+      input-report-header-address = <0x1000>;
+      input-report-body-address = <0x1004>;
+      output-report-address = <0x2000>;
+      read-opcode = <0x0b>;
+      write-opcode = <0x02>;
+      hid-over-spi-flags = <0x00>;
+      post-power-on-delay-ms = <5>;
+      minimal-reset-delay-ms = <5>;
+    };
-- 
2.25.1
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help