lkml.org 
[lkml]   [2019]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH RESEND 3/4] dt-bindings: drm/bridge: Add GPIO display mux binding
On Wed, Dec 11, 2019 at 12:19 AM Hsin-Yi Wang <hsinyi@chromium.org> wrote:
>
> From: Nicolas Boichat <drinkcat@chromium.org>
>
> Add bindings for Generic GPIO mux driver.
>
> Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> ---
> Change from RFC to v1:
> - txt to yaml
> ---
> .../bindings/display/bridge/gpio-mux.yaml | 89 +++++++++++++++++++
> 1 file changed, 89 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/display/bridge/gpio-mux.yaml
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/gpio-mux.yaml b/Documentation/devicetree/bindings/display/bridge/gpio-mux.yaml
> new file mode 100644
> index 000000000000..cef098749066
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/gpio-mux.yaml
> @@ -0,0 +1,89 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/bridge/gpio-mux.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Generic display mux (1 input, 2 outputs)

What makes it generic? Doesn't the mux chip have power supply,
possibly a reset line or not, etc.? What about a mux where the GPIO
controls the mux?

Generally, we avoid 'generic' bindings because h/w is rarely generic.
You can have a generic driver which works on multiple devices.

> +
> +maintainers:
> + - Nicolas Boichat <drinkcat@chromium.org>
> +
> +description: |
> + This bindings describes a simple display (e.g. HDMI) mux, that has 1
> + input, and 2 outputs. The mux status is controlled by hardware, and
> + its status is read back using a GPIO.
> +
> +properties:
> + compatible:
> + const: gpio-display-mux
> +
> + detect-gpios:
> + maxItems: 1
> + description: GPIO that indicates the active output
> +
> + ports:
> + type: object
> +
> + properties:
> + port@0:
> + type: object
> + description: |
> + Video port for input.
> +
> + port@1:
> + type: object
> + description: |
> + 2 video ports for output.
> + The reg value in the endpoints matches the GPIO status: when
> + GPIO is asserted, endpoint with reg value <1> is selected.

You should describe 'endpoint@0' and 'endpoint@1' here too.

> +
> + required:
> + - port@0
> + - port@1
> +
> +required:
> + - compatible
> + - detect-gpios
> + - ports
> +
> +examples:
> + - |
> + hdmi_mux: hdmi_mux {
> + compatible = "gpio-display-mux";
> + status = "okay";

Don't show status in examples.

> + detect-gpios = <&pio 36 GPIO_ACTIVE_HIGH>;
> + pinctrl-names = "default";
> + pinctrl-0 = <&hdmi_mux_pins>;
> + ddc-i2c-bus = <&hdmiddc0>;

Not documented. Is the i2c bus muxed too? If not, then this is in the
wrong place.

> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port@0 { /* input */
> + reg = <0>;
> +
> + hdmi_mux_in: endpoint {
> + remote-endpoint = <&hdmi0_out>;
> + };
> + };
> +
> + port@1 { /* output */
> + reg = <1>;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + hdmi_mux_out_anx: endpoint@0 {
> + reg = <0>;
> + remote-endpoint = <&anx7688_in>;
> + };
> +
> + hdmi_mux_out_hdmi: endpoint@1 {
> + reg = <1>;
> + remote-endpoint = <&hdmi_connector_in>;
> + };
> + };
> + };
> + };
> --
> 2.24.0.525.g8f36a354ae-goog
>

\
 
 \ /
  Last update: 2019-12-13 23:18    [W:0.085 / U:0.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site