Re: [PATCH v3 2/5] dt-bindings: auxdisplay: Add Titan Micro Electronics TM1628

On 24.02.2022 22:30, Rob Herring wrote:

On Thu, Feb 24, 2022 at 2:56 PM Heiner Kallweit [off-list ref] wrote:

quoted

On 24.02.2022 21:22, Rob Herring wrote:

quoted

On Wed, Feb 23, 2022 at 06:59:31PM +0100, Heiner Kallweit wrote:

quoted

Add a YAML schema binding for TM1628 auxdisplay
(7/11-segment LED) controller.

This patch is partially based on previous work from
Andreas Färber [off-list ref].

Co-Developed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Co-Developed-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
v3:
- fix remaining YAML issues
- use Co-Developed-by
---
 .../bindings/auxdisplay/titanmec,tm1628.yaml  | 92 +++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml

diff --git a/Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml b/Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml
new file mode 100644
index 000000000..2a1ef692c
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml

@@ -0,0 +1,92 @@
+# SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/titanmec,tm1628.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Titan Micro Electronics TM1628 LED controller
+
+maintainers:
+  - Andreas Färber <afaerber@suse.de>
+  - Heiner Kallweit <hkallweit1@gmail.com>
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    const: titanmec,tm1628
+
+  reg:
+    maxItems: 1
+

quoted

+  grid:
+    description:
+      Mapping of display digit position to grid number.
+      This implicitly defines the display size.
+    $ref: /schemas/types.yaml#/definitions/uint8-array
+    minItems: 1
+    maxItems: 7
+
+  segment-mapping:
+    description:
+      Mapping of 7 segment display segments A-G to bit numbers 1-12.
+    $ref: /schemas/types.yaml#/definitions/uint8-array
+    minItems: 7
+    maxItems: 7

Are these properties useful for any 7 segment display or specific to
this controller?

Both are controller-specific. E.g. the functionally similar driver
ht16k33 uses different properties.

Then they both need a vendor prefix.

OK, will add the prefix. Thanks for the hint.

quoted

quoted

The commit msg mentions 11 segment display. Does this need to be?:

oneOf:
  - minItems: 7
    maxItems: 7
  - minItems: 11
    maxItems: 11

The controller would be able to drive 11 segments, but the driver
supports 7 segments only (at least for now). Therefore a 11 segment
display can be used, but only the 7 segment part will be active.
All devices with this controller I've seen and heard of have
7 segment displays.

Bindings should be complete, not just what a particular version of a
driver supports. However, if all known h/w is just 7 seg, then it is
fine.

Rob