Messages in this thread | | | Subject | Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger | From | Jacek Anaszewski <> | Date | Thu, 25 Aug 2016 20:48:04 +0200 |
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On 08/25/2016 04:30 PM, Alan Stern wrote: > On Thu, 25 Aug 2016, Jacek Anaszewski wrote: > >> I'd see it as follows: >> >> #cat available_ports >> #1-1 1-2 2-1 >> >> #echo "1-1" > new_port >> >> #cat observed_ports >> #1-1 >> >> #echo "2-1" > new_port >> >> #cat observed_ports >> #1-1 2-1 >> >> We've already had few discussions about the sysfs designs trying >> to break the one-value-per-file rule for LED class device, and >> there was always strong resistance against. > > This scheme has multiple values in both the available_ports and > observed_ports files. :-( Not that I have any better suggestions...
Right, I forgot to add a note here, that this follows space separated list pattern similarly as in case of triggers attribute. Of course other suggestions are welcome.
>>>> Also a description of the device connected to the port would be a nice >>>> feature, however I am not certain about the feasibility thereof. >>> >>> What kind of description do you mean? Where should it be used / where >>> should it appear? >>> >> >> Product name/symbol. Actually it should be USB subsystem responsibility >> to provide the means for querying the product name by port id, if it >> is possible at all. > > cat /sys/bus/usb/devices/PORT/product > cat /sys/bus/usb/devices/PORT/manufacturer > > These will work if there is a device registered under PORT.
I've found only idProduct and idVendor files. They indeed uniquely identify the device, but the numbers are not human readable. Is there a way to retrieve the corresponding names in kernel? Does the lsusb command do the mapping in the user space or maybe it takes the names from kernel?
-- Best regards, Jacek Anaszewski
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