Re: [PATCH/RFC v9 02/19] Documentation: leds: Add description of LED Flash class extension

From: Jacek Anaszewski
Date: Tue Dec 09 2014 - 08:14:39 EST

Hi Sakari,

On 12/09/2014 01:38 PM, Sakari Ailus wrote:


How does the user btw. figure out which flash LEDs may be strobed
synchronously using the LED flash interface?

The flash_sync_strobe argument is absent if synchronized strobe
is not available for a LED. The driver defines this by setting
newly added LED_DEV_CAP_COMPOUND flag.

I meant that how does the user figure out which LEDs may be strobed
synchronously, together. Say, if you have two of these chips and four LEDs,
then how does it work? :-)

User can figure it out by checking the existence of the
flash_sync_strobe attribute. Sub-leds can by synchronized only
when are driven by common chip. It is assumed that sub-leds of
one chip will have common segment in their name, defined in
DT 'label' property. Maybe we should enforce it by adding another
property to the leds/common.txt DT binding, e.g. 'device-prefix'?

Best Regards,
Jacek Anaszewski

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