Hi,
See below.
On 24.3.2021 9.56, Hermes Zhang wrote:
From: Hermes Zhang <chenh...@axis.com>
Document the device tree bindings of the multiple GPIOs LED driver
Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml.
Signed-off-by: Hermes Zhang <chenh...@axis.com>
---
.../bindings/leds/leds-multi-gpio.yaml | 50 +++++++++++++++++++
1 file changed, 50 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml
diff --git a/Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml
b/Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml
new file mode 100644
index 000000000000..6f2b47487b90
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-multi-gpio.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/leds-multi-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Multiple GPIOs LED driver
+
+maintainers:
+ - Hermes Zhang <chenh...@axis.com>
+
+description:
+ This will support some LED made of multiple GPIOs and the brightness of the
+ LED could map to different states of the GPIOs.
+
+properties:
+ compatible:
+ const: multi-gpio-led
+
+ led-gpios:
+ description: Array of one or more GPIOs pins used to control the LED.
+ minItems: 1
+ maxItems: 8 # Should be enough
We also have a case with multi color LEDs (which is probably a more
common than multi intensity LED. So I am wondering how these both could
co-exist.
From:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/leds/leds-gpio.yaml?h=v5.12-rc4#n58
led-0 {
gpios = <&mcu_pio 0 GPIO_ACTIVE_LOW>;
linux,default-trigger = "disk-activity";
function = LED_FUNCTION_DISK;
};
Now 'gpios' (and in LED context) and 'led-gpios' is very close to each
other and could easily be confused.
Perhaps this could be something like:
intensity-gpios = ...
or even simplified then just to gpios = <...>
+
+ led-states:
+ description: |
+ The array list the supported states here which will map to brightness
+ from 0 to maximum. Each item in the array will present all the GPIOs
+ value by bit.
+ $ref: /schemas/types.yaml#/definitions/uint8-array
+ minItems: 1
+ maxItems: 16 # Should be enough
+
+required:
+ - compatible
+ - led-gpios
+ - led-states
+
+additionalProperties: false
+
+examples:
+ - |
+ gpios-led {
+ compatible = "multi-gpio-led";
+
+ led-gpios = <&gpio0 23 0x1>,
+ <&gpio0 24 0x1>;
+ led-states = /bits/ 8 <0x00 0x01 0x02 0x03>;
+ };
+...
From:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/leds/leds-lp55xx.yaml?h=v5.12-rc4#n196
There is example of multi color LED configuration. In example below I
used two-color LED with red and green as an example (which what we seem
to have most in use).
Then if try to combine these into something like:
# Multi color LED with single GPIO line per color
multi-led@2 {
compatible = "gpio-leds";
color = <LED_COLOR_ID_MULTICOLOR>;
led@0 {
color = <LED_COLOR_ID_GREEN>;
gpios = <&mcu_pio 0 GPIO_ACTIVE_LOW>;
};
led@1 {
color = <LED_COLOR_ID_RED>;
gpios = <&mcu_pio 1 GPIO_ACTIVE_LOW>;
};
};
# And with intensity GPIOs:
multi-led@2 {
compatible = "gpio-leds";
color = <LED_COLOR_ID_MULTICOLOR>;
led@0 {
color = <LED_COLOR_ID_GREEN>;
gpios = <&gpio0 23 0x1>,
<&gpio0 24 0x1>;
... see below
};
led@1 {
color = <LED_COLOR_ID_RED>;
gpios = <&gpio0 25 0x1>,
<&gpio0 26 0x1>;
... see below
};
};
# And then single GPIO with intensity GPIOs:
led@2 {
compatible = "gpio-leds";
gpios = <&gpio0 23 0x1>,
<&gpio0 24 0x1>;
gpios-brightness-levels = <0 1 2 3>
};
I changed 'led-states' to 'gpios-brightness-levels' as it describe more
that this is about brightness and not some other state information.
How would this sound?
Thanks,
Vesa Jääskeläinen
