From patchwork Wed Apr 8 22:57:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Glass X-Patchwork-Id: 237465 List-Id: U-Boot discussion From: sjg at chromium.org (Simon Glass) Date: Wed, 8 Apr 2020 16:57:32 -0600 Subject: [PATCH v5 13/29] dts: Add a binding for hid-over-i2c In-Reply-To: <20200408225749.171380-1-sjg@chromium.org> References: <20200408225749.171380-1-sjg@chromium.org> Message-ID: <20200408225749.171380-2-sjg@chromium.org> Add this binding from Linux v5.4. Signed-off-by: Simon Glass Reviewed-by: Bin Meng --- Changes in v5: None Changes in v4: None Changes in v3: - Split out hid-over-i2c into its own patch Changes in v2: None .../input/hid-over-i2c.txt | 44 +++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 doc/device-tree-bindings/input/hid-over-i2c.txt diff --git a/doc/device-tree-bindings/input/hid-over-i2c.txt b/doc/device-tree-bindings/input/hid-over-i2c.txt new file mode 100644 index 00000000000..c76bafaf98d --- /dev/null +++ b/doc/device-tree-bindings/input/hid-over-i2c.txt @@ -0,0 +1,44 @@ +* HID over I2C Device-Tree bindings + +HID over I2C provides support for various Human Interface Devices over the +I2C bus. These devices can be for example touchpads, keyboards, touch screens +or sensors. + +The specification has been written by Microsoft and is currently available here: +http://msdn.microsoft.com/en-us/library/windows/hardware/hh852380.aspx + +If this binding is used, the kernel module i2c-hid will handle the communication +with the device and the generic hid core layer will handle the protocol. + +Required properties: +- compatible: must be "hid-over-i2c" +- reg: i2c slave address +- hid-descr-addr: HID descriptor address +- interrupts: interrupt line + +Additional optional properties: + +Some devices may support additional optional properties to help with, e.g., +power sequencing. The following properties can be supported by one or more +device-specific compatible properties, which should be used in addition to the +"hid-over-i2c" string. + +- compatible: + * "wacom,w9013" (Wacom W9013 digitizer). Supports: + - vdd-supply (3.3V) + - vddl-supply (1.8V) + - post-power-on-delay-ms + +- vdd-supply: phandle of the regulator that provides the supply voltage. +- post-power-on-delay-ms: time required by the device after enabling its regulators + or powering it on, before it is ready for communication. + +Example: + + i2c-hid-dev at 2c { + compatible = "hid-over-i2c"; + reg = <0x2c>; + hid-descr-addr = <0x0020>; + interrupt-parent = <&gpx3>; + interrupts = <3 2>; + };