On Mon, Feb 14, 2022 at 11:45:17PM +0100, Andreas Kemnade wrote:
Hi Rob,
On Fri, 11 Feb 2022 09:46:27 -0600 Rob Herring robh@kernel.org wrote:
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?
it has some differences, but that could be detected by EPDC_VERSION register. I do not own such a device, so I cannot fully check. I have not seen any driver with devicetree for IMX5. For now I am rejecting anything which has a EPDC version which I cannot check.
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@kemnade.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@kemnade.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-epdcNot compatible with each other?
differences are detectable by EPDC_VERSION register, so probably so problem. NXP/Freescale kernel uses fsl,imx6dl-epdc and fsl,imx7d-epdc (used also by imx6 devices with EPDC_VERSION = 3.0) in their drivers.
fsl,imx6dl-epdc fsl,imx6sl-epdc fsl,imx6sll-epdc fsl,imx7d-epdc in their dtsis.
But the general rule is to use as less as possible compatible strings if differences can be probed properly, so only one should be sufficient? Which one?
If you can probe all the differences, then just 'fsl,imx-epdc' is sufficient. Just document that so the next time around I don't forget and tell you it needs to be specific.
Rob