On Thu, Jan 08, 2015 at 08:40:20AM -0600, Rob Herring wrote:

On Thu, Jan 8, 2015 at 2:45 AM, Olliver Schinagl [off-list ref] wrote:

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Hey Dmitry,


On 08-01-15 00:55, Dmitry Torokhov wrote:

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On Wed, Jan 07, 2015 at 10:08:42AM +0100, Olliver Schinagl wrote:

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From: Olliver Schinagl <redacted>

The gpio document says we should not use unnamed bindings for gpios.
This patch uses the 'led-' prefix to the gpios and updates code and
documents. Because the devm_get_gpiod_from_child() falls back to using
old-style unnamed gpios, we can update the code first, and update
dts files as time allows.

[...]

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--- a/drivers/leds/leds-gpio.c
+++ b/drivers/leds/leds-gpio.c

@@ -184,7 +184,7 @@ static struct gpio_leds_priv *gpio_leds_create(struct

platform_device *pdev)
                struct gpio_led led = {};
                const char *state = NULL;
  -             led.gpiod = devm_get_gpiod_from_child(dev, NULL, child);
+               led.gpiod = devm_get_gpiod_from_child(dev, "led", child);

Would not this break existing boards using old bindings? You need to
handle both cases: if you can't located "led-gpios" then you will have to
try just "gpios".

Very true. I was rather even hoping we could update all bindings, I don't
mind going through the available dts files to fix them ... But need to know
that that's the proper way to go before doing the work ;)

That will not work. You cannot make changes that require a new dtb
with a new kernel. This would also break for the other way around
(i.e. a new dtb and old kernel).

You would have to search for both led-gpios and gpios. I'm not sure if
we can do that generically for all GPIOs. If you had a node with both
"blah-gpios" and "gpios", it would break. I would hope there are no
such cases like that. We also now have to consider how ACPI identifies
GPIOs and whether this makes sense.

I think only the driver itself can know about such "legacy" mappings and
make a decision.

Thanks.

-- 
Dmitry