Hi Pavel,
On 02/20/2015 09:16 AM, Pavel Machek wrote:
Hi!
+What: /sys/class/leds/<led>/available_sync_leds
+Date: February 2015
+KernelVersion: 3.20
+Contact: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
+Description: read/write
+ Space separated list of LEDs available for flash strobe
+ synchronization, displayed in the format:
+
+ led1_id.led1_name led2_id.led2_name led3_id.led3_name etc.
Multiple values per file, with all the problems we had in /proc. I
assume led_id is an integer? What prevents space or dot in led name?
Very good point. How about using a newline instead? That'd be a little bit
easier to parse, too.
No, please make it one value per-file, which is what sysfs requires.
The purpose of this attribute is only to provide an information about
the range of valid identifiers that can be written to the
flash_sync_strobe attribute. Wouldn't splitting this to many attributes
be an unnecessary inflation of sysfs files?
No, it would not. It is required so that we don't end up with broken
parsers.
Let's discuss the acceptable approach then. I propose a directory
named synchronized_strobe and containing the files as you proposed
in one of the previous messages: led_id.active and led_id.name.
The attribute flash_sync_strobe would be redundant then and should
be removed.
Use cases for two LEDs:
- max77693-led1
- max77693-led2
#cd synchronized_strobe
#ls
#0.active 0.name 1.active 1.name
#cat 0.name
#max77693-led1
#cat 0.active
#0
#cat 1.name
#max77693-led2
#cat 1.active
#0
#echo 1 > 0.active
#cat 0.active
#1
#echo 1 > 1.active
#cat 0.active
#0
#cat 1.active
#1
Apart from it, we have also flash_faults attribute, that currently
provides a space separated list of flash faults that have occurred.
If we are to stick tightly to the one-value-per-file rule, then how
we should approach flash_faults case? Should the separate file be
dynamically created for each reported fault?
I think you can get away with flash_faults attribute (since the
strings are hardcoded).
If so, the attribute will be left as is.
Dynamically created files would be extremely ugly interface, but you
could also have files such as "overvoltage_fault" containing either 0
or 1 ...
--
Best Regards,
Jacek Anaszewski
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