On Fri, 12 Mar 2021 10:12:26 +0100
Rafał Miłecki [off-list ref] wrote:

On 12.03.2021 09:23, Marek Behun wrote:

quoted

On Fri, 12 Mar 2021 08:52:16 +0100
Rafał Miłecki [off-list ref] wrote:
  

quoted

On 12.03.2021 08:44, Marek Behun wrote:  

quoted

On Wed, 10 Mar 2021 08:00:25 +0100
Rafał Miłecki [off-list ref] wrote:
     

quoted

From: Rafał Miłecki <rafal@milecki.pl>

The old regex allowed only 1 character to follow the "led-" prefix which
was most likely just an overlook. Fix it and while at it allow dashes in
node names. It allows more meaningful names and it helpful e.g. when
having the same function name with 2 different colors. For example:
1. led-power-white
2. led-power-blue

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
   Documentation/devicetree/bindings/leds/leds-gpio.yaml | 2 +-
   1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/leds/leds-gpio.yaml b/Documentation/devicetree/bindings/leds/leds-gpio.yaml
index 7ad2baeda0b0..ae46a43e480f 100644
--- a/Documentation/devicetree/bindings/leds/leds-gpio.yaml
+++ b/Documentation/devicetree/bindings/leds/leds-gpio.yaml

@@ -21,7 +21,7 @@ properties:
   patternProperties:
     # The first form is preferred, but fall back to just 'led' anywhere in the
     # node name to at least catch some child nodes.
-  "(^led-[0-9a-f]$|led)":
+  "(^led-[0-9a-f][0-9a-f-]*$|led)":  

Why not use +, like everywhere else?
    "(^led-[0-9a-f]+$|led)"  

1. Your regex doesn't allow dashes. I described that in commit message.  

Ah, I confess I did not read the commit message. My fault.
  

quoted

2. If I use one range and +, that will allow unwanted names like "led--power"  

But this can happen anyway. Your regex will match for example
"led-deaf------beef".  

You're right. I probably was overthinking that ;)

quoted

Moreover you give as an example names
   led-power-white
   led-power-blue
but the regex only allows hexadecimal characters, ie
   led-dead-beef
   led-1f-3

The idea is that the string after "led-" is a hexadecimal address.
Names like
   led-power-white
shouldn't be used, as far as I understand.  

Oops!
1. My regex was meant to be [0-9][a-z-][0-9][a-z-]+
2. I totally missed that nodename should contain hex num and not a name

My patch is based on bad binding understanding.


So as I understand it now, the point of led hex number is to enumerate
nodes. That way we avoid:
ERROR (duplicate_node_names): /leds/led: Duplicate node name


I'm just wondering if there is some cleaner solution than using those
led-0, led-1, led-2, led-3, led-4 (...) names.

Would that be acceptable to use address with GPIO number? Example:

leds {
	compatible = "gpio-leds";
	led@6 {
		gpios = <&mpc8572 6 GPIO_ACTIVE_HIGH>;
		color = <LED_COLOR_ID_RED>;
	};
	led@7 {
		gpios = <&mpc8572 7 GPIO_ACTIVE_HIGH>;
		color = <LED_COLOR_ID_GREEN>;
	};
};

I don't know. This is a question for Rob Herring.
But why is led-0, led-1, led-2 not good enough?
You can still define function via the function property:
 led-7 {
   gpios = <&mpc8572 7 GPIO_ACTIVE_HIGH>;
   color = <LED_COLOR_ID_GREEN>;
   function = LED_FUNCTION_POWER;
 };