[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <YgaE06Ktabpf2dJC@robh.at.kernel.org>
Date: Fri, 11 Feb 2022 09:46:27 -0600
From: Rob Herring <robh@...nel.org>
To: Andreas Kemnade <andreas@...nade.info>
Cc: p.zabel@...gutronix.de, airlied@...ux.ie, daniel@...ll.ch,
shawnguo@...nel.org, s.hauer@...gutronix.de, kernel@...gutronix.de,
festevam@...il.com, linux-imx@....com,
maarten.lankhorst@...ux.intel.com, mripard@...nel.org,
tzimmermann@...e.de, dri-devel@...ts.freedesktop.org,
devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
linux-kernel@...r.kernel.org, alistair@...stair23.me,
samuel@...lland.org, josua.mayer@....eu,
letux-kernel@...nphoenux.org
Subject: Re: [RFC PATCH 1/6] dt-bindings: display: imx: Add EPDC
On Sun, Feb 06, 2022 at 09:00:11AM +0100, Andreas Kemnade wrote:
> Add a binding for the Electrophoretic Display Controller found at least
> in the i.MX6.
The first version was in i.MX50 (I helped design the register
interface). Is that version compatible?
> The timing subnode is directly here to avoid having display parameters
> spread all over the plate.
>
> Supplies are organized the same way as in the fbdev driver in the
> NXP/Freescale kernel forks. The regulators used for that purpose,
> like the TPS65185, the SY7636A and MAX17135 have typically a single bit to
> start a bunch of regulators of higher or negative voltage with a
> well-defined timing. VCOM can be handled separately, but can also be
> incorporated into that single bit.
>
> Signed-off-by: Andreas Kemnade <andreas@...nade.info>
> ---
> .../bindings/display/imx/fsl,mxc-epdc.yaml | 159 ++++++++++++++++++
> 1 file changed, 159 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/display/imx/fsl,mxc-epdc.yaml
>
> diff --git a/Documentation/devicetree/bindings/display/imx/fsl,mxc-epdc.yaml b/Documentation/devicetree/bindings/display/imx/fsl,mxc-epdc.yaml
> new file mode 100644
> index 000000000000..7e0795cc3f70
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/imx/fsl,mxc-epdc.yaml
> @@ -0,0 +1,159 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/imx/fsl,mxc-epdc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Freescale i.MX6 EPDC
> +
> +maintainers:
> + - Andreas Kemnade <andreas@...nade.info>
> +
> +description: |
> + The EPDC is a controller for handling electronic paper displays found in
> + i.MX6 SoCs.
> +
> +properties:
> + compatible:
> + enum:
> + - fsl,imx6sl-epdc
> + - fsl,imx6sll-epdc
Not compatible with each other?
> +
> + reg:
> + maxItems: 1
> +
> + clocks:
> + items:
> + - description: Bus clock
> + - description: Pixel clock
> +
> + clock-names:
> + items:
> + - const: axi
> + - const: pix
> +
> + interrupts:
> + maxItems: 1
> +
> + vscan-holdoff:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maxItems: 1
> +
> + sdoed-width:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maxItems: 1
> +
> + sdoed-delay:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maxItems: 1
> +
> + sdoez-width:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maxItems: 1
> +
> + sdoez-delay:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maxItems: 1
> +
> + gdclk-hp-offs:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maxItems: 1
> +
> + gdsp-offs:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maxItems: 1
> +
> + gdoe-offs:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maxItems: 1
> +
> + gdclk-offs:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maxItems: 1
> +
> + num-ce:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + maxItems: 1
All these need a vendor prefix and descriptions.
> +
> + timing:
> + $ref: /display/panel/panel-timing.yaml#
> +
> + DISPLAY-supply:
> + description:
> + A couple of +/- voltages automatically powered on in a defintive order
> +
> + VCOM-supply:
> + description: compensation voltage
> +
> + V3P3-supply:
> + description: V3P3 supply
> +
> + epd-thermal-zone:
> + description:
> + Zone to get temperature of the EPD from, practically ambient temperature.
> +
> +
> +
1 blank line.
> +required:
> + - compatible
> + - reg
> + - clocks
> + - clock-names
> + - interrupts
> + - vscan-holdoff
> + - sdoed-width
> + - sdoed-delay
> + - sdoez-width
> + - sdoez-delay
> + - gdclk-hp-offs
> + - gdsp-offs
> + - gdoe-offs
> + - gdclk-offs
> + - num-ce
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/clock/imx6sl-clock.h>
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> + epdc: epdc@...4000 {
> + compatible = "fsl,imx6sl-epdc";
> + reg = <0x020f4000 0x4000>;
> + interrupts = <0 97 IRQ_TYPE_LEVEL_HIGH>;
> + clocks = <&clks IMX6SL_CLK_EPDC_AXI>, <&clks IMX6SL_CLK_EPDC_PIX>;
> + clock-names = "axi", "pix";
> +
> + pinctrl-names = "default";
> + pinctrl-0 = <&pinctrl_epdc0>;
> + V3P3-supply = <&V3P3_reg>;
> + VCOM-supply = <&VCOM_reg>;
> + DISPLAY-supply = <&DISPLAY_reg>;
> + epd-thermal-zone = "epd-thermal";
> +
> + vscan-holdoff = <4>;
> + sdoed-width = <10>;
> + sdoed-delay = <20>;
> + sdoez-width = <10>;
> + sdoez-delay = <20>;
> + gdclk-hp-offs = <562>;
> + gdsp-offs = <662>;
> + gdoe-offs = <0>;
> + gdclk-offs = <225>;
> + num-ce = <3>;
> + status = "okay";
Don't need status in examples.
> +
> + timing {
> + clock-frequency = <80000000>;
> + hactive = <1448>;
> + hback-porch = <16>;
> + hfront-porch = <102>;
> + hsync-len = <28>;
> + vactive = <1072>;
> + vback-porch = <4>;
> + vfront-porch = <4>;
> + vsync-len = <2>;
> + };
> + };
> +...
> --
> 2.30.2
>
>
Powered by blists - more mailing lists