tlp-usblist

#!/usr/bin/perl
# tlp-usblist - list usb device info with autosuspend attributes
#
# Copyright (c) 2016 Thomas Koch <linrunner at gmx.net>
# This software is licensed under the GPL v2 or later.

package tlp_usblist;
use strict;
use warnings;

# --- Constants
use constant USBD => "/sys/bus/usb/devices";

# --- Global vars
my %usbdevices;
my $udev;

my $no_runtimepm = 0;

# --- Subroutines

# Read content from a sysfile
# $_[0]: input file
# return: content / empty string if nonexistent or not readable
sub catsysf {
    my $sysval = "";
    if (open (SYSF, "$_[0]")) {
        chomp ($sysval = <SYSF>);
        close (SYSF);
    }
    return $sysval;
}

# Read device driver from DEVICE/uevent
# $_[0]: (sub)device base path
# return: driver / empty string if uevent nonexistent or not readable
sub getdriver {
    my $driver = "";

    if ( open (SYSF, "$_[0]/uevent") ) {
        # read file line by line
        while (<SYSF>) {
            # match line content and return DRIVER= value
            if ( s/^DRIVER=(.*)/$1/ ) {
                chomp ($driver = $_);
                last; # break loop
            }
        }
        close (SYSF);
    }
    return $driver
}

# Get drivers associated with USB device by iterating subdevices
# $_[0]: device base path
# return:  driver list / "no driver" if none found
sub usbdriverlist {
    my $driverlist = "";
    my $subdev;

    # iterate subdevices
    foreach $subdev (glob "$_[0]/*:*") {
        # get subdevice driver
        my $driver = getdriver ("$subdev");
        if ( $driver ) {
            if (index ($driverlist, $driver) == -1) {
                if ($driverlist) { $driverlist = $driverlist . ", " . $driver; }
                else { $driverlist = $driver; }
            } # if index
        } # if $driver
    } # foreach $subdev

    if (! $driverlist) { $driverlist = "no driver"; }
    return $driverlist
}

# --- MAIN

# Check if Runtime PM is enabled
$no_runtimepm = 1 if ( ! glob USBD . "/*/power/autosuspend*");

# Read USB device tree attributes as arrays into %usbdevices hash, indexed by Bus_Device
foreach $udev (grep { ! /:/ } glob USBD . "/*") {
    my ($asf, $asv);
    my ($cnf, $cnv);
    my $usbv = "(autosuspend not available)";

    # get device id
    my $usbk = sprintf ("%03d_%03d", catsysf ("$udev/busnum"), catsysf ("$udev/devnum") );

    # look for autosuspend_delay_ms then autosuspend (deprecated)
    foreach $asf ( "autosuspend_delay_ms", "autosuspend" ) {
        if ( length ( $asv = catsysf ("$udev/power/$asf") ) ) {
            # autosuspend* exists --> check for control then level (deprecated)
            foreach $cnf ( "control", "level" ) {
                if ( $cnv = catsysf ("$udev/power/$cnf") ) {
                    if ( $asf eq "autosuspend_delay_ms" ) {
                            $usbv = sprintf ("%s = %-5s %s = %5d", $cnf, $cnv . ",", $asf, $asv);
                    } else {
                            $usbv = sprintf ("%s = %-5s %s = %2d", $cnf, $cnv . ",", $asf, $asv);
                    }
                    last; # break loop
                }
            }
            last; # break loop
        }
    }

    # save formatted result in hash
    @{$usbdevices{$usbk}} = ($udev, $usbv);
}

# Output device list with attributes and drivers
foreach (`lsusb 2> /dev/null`) {
    my ($bus, $dev, $usbid, $desc) = /Bus (\S+) Device (\S+): ID (\S+)[ ]+(.*)/;
    my $usbk = $bus . "_" . $dev;
    $desc ||= "<unknown>";
    print "Bus $bus Device $dev ID $usbid $usbdevices{$usbk}[1] -- $desc ("
        . usbdriverlist ($usbdevices{$usbk}[0]) . ")\n";
}

exit 4 if ( $no_runtimepm == 1 );

exit 0;