Hi Oleh,
On 6/7/19 11:48 PM, Oleh Kravchenko wrote:
Jacek,
08.06.19 00:23, Jacek Anaszewski пише:
Hi Oleh.
On 6/7/19 11:17 PM, Oleh Kravchenko wrote:
Dan,
On 08.06.19 00:04, Dan Murphy wrote:
Oleh
But this is not really max_brightness now this is a feature and now
does not make sense in this context
You may need to use something different for this property or expose
a file in the driver.
Protocol for this board define 0x32 as brightness level.
This behaviur needed to keep backward compatibity.
Backwards compatibility to what?
With old/new boards.
You have in your driver the following:
+ * BRIGHTNESS Can be 0x30 (OFF), 0x31 (ON).
+ * 0x32 (Effect) can be used for 0x50 (leaking) and
+ * for 0x53 (blinking)
If your max-brightness DT property is to be used for controlling this,
then I don't see how it would be backward compatible with anything.
Clearly, you don't need max-brightness DT property at all.
What I should do with board which accept brightness in range 0x30 - 0x3a?
Where 0x3a means special effect.
I believe 0x3a is a typo since above you have 0x32 for the effect.
Anyway, we shouldn't propagate hardware design flaws to the userspace
interface. You have ON/OFF register values for manipulating brightness,
so use them appropriately. struct led_classdev's max_brightness property
should be set to 1, as already pointed out by Dan.
For blinking you can use blink_set op. To be able to recommend
you anoptimal solution for the effect we would need more
details regarding its nature.
Thanks, I will do that.
But how to properly handle other effects? Not only blinking?
For the effects we could probably use pattern trigger, but we need
more information on how it can be configured.
And how to define it by device tree?
Driver can't get this information about what is really supported.
I don't want define effect code inside DT.
We now have led-pattern DT property, which allows to initialize a LED
with the DT provided pattern
(see Documentation/devicetree/bindings/leds/common.txt).
This is a new driver there should be no DT that has this compatible or
definition.
I will let Rob ack or nack this node.
Dan
--
Best regards,
Jacek Anaszewski
