--- /dev/null
+#! /bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2020, Google LLC. All rights reserved.
+# Author: Saravana Kannan <saravanak@google.com>
+
+function help() {
+ cat << EOF
+Usage: $(basename $0) [-c|-d|-m|-f] [filter options] <list of devices>
+
+This script needs to be run on the target device once it has booted to a
+shell.
+
+The script takes as input a list of one or more device directories under
+/sys/devices and then lists the probe dependency chain (suppliers and
+parents) of these devices. It does a breadth first search of the dependency
+chain, so the last entry in the output is close to the root of the
+dependency chain.
+
+By default it lists the full path to the devices under /sys/devices.
+
+It also takes an optional modifier flag as the first parameter to change
+what information is listed in the output. If the requested information is
+not available, the device name is printed.
+
+ -c lists the compatible string of the dependencies
+ -d lists the driver name of the dependencies that have probed
+ -m lists the module name of the dependencies that have a module
+ -f list the firmware node path of the dependencies
+ -g list the dependencies as edges and nodes for graphviz
+ -t list the dependencies as edges for tsort
+
+The filter options provide a way to filter out some dependencies:
+ --allow-no-driver By default dependencies that don't have a driver
+ attached are ignored. This is to avoid following
+ device links to "class" devices that are created
+ when the consumer probes (as in, not a probe
+ dependency). If you want to follow these links
+ anyway, use this flag.
+
+ --exclude-devlinks Don't follow device links when tracking probe
+ dependencies.
+
+ --exclude-parents Don't follow parent devices when tracking probe
+ dependencies.
+
+EOF
+}
+
+function dev_to_detail() {
+ local i=0
+ while [ $i -lt ${#OUT_LIST[@]} ]
+ do
+ local C=${OUT_LIST[i]}
+ local S=${OUT_LIST[i+1]}
+ local D="'$(detail_chosen $C $S)'"
+ if [ ! -z "$D" ]
+ then
+ # This weirdness is needed to work with toybox when
+ # using the -t option.
+ printf '%05u\t%s\n' ${i} "$D" | tr -d \'
+ fi
+ i=$((i+2))
+ done
+}
+
+function already_seen() {
+ local i=0
+ while [ $i -lt ${#OUT_LIST[@]} ]
+ do
+ if [ "$1" = "${OUT_LIST[$i]}" ]
+ then
+ # if-statement treats 0 (no-error) as true
+ return 0
+ fi
+ i=$(($i+2))
+ done
+
+ # if-statement treats 1 (error) as false
+ return 1
+}
+
+# Return 0 (no-error/true) if parent was added
+function add_parent() {
+
+ if [ ${ALLOW_PARENTS} -eq 0 ]
+ then
+ return 1
+ fi
+
+ local CON=$1
+ # $CON could be a symlink path. So, we need to find the real path and
+ # then go up one level to find the real parent.
+ local PARENT=$(realpath $CON/..)
+
+ while [ ! -e ${PARENT}/driver ]
+ do
+ if [ "$PARENT" = "/sys/devices" ]
+ then
+ return 1
+ fi
+ PARENT=$(realpath $PARENT/..)
+ done
+
+ CONSUMERS+=($PARENT)
+ OUT_LIST+=(${CON} ${PARENT})
+ return 0
+}
+
+# Return 0 (no-error/true) if one or more suppliers were added
+function add_suppliers() {
+ local CON=$1
+ local RET=1
+
+ if [ ${ALLOW_DEVLINKS} -eq 0 ]
+ then
+ return 1
+ fi
+
+ SUPPLIER_LINKS=$(ls -1d $CON/supplier:* 2>/dev/null)
+ for SL in $SUPPLIER_LINKS;
+ do
+ SYNC_STATE=$(cat $SL/sync_state_only)
+
+ # sync_state_only links are proxy dependencies.
+ # They can also have cycles. So, don't follow them.
+ if [ "$SYNC_STATE" != '0' ]
+ then
+ continue
+ fi
+
+ SUPPLIER=$(realpath $SL/supplier)
+
+ if [ ! -e $SUPPLIER/driver -a ${ALLOW_NO_DRIVER} -eq 0 ]
+ then
+ continue
+ fi
+
+ CONSUMERS+=($SUPPLIER)
+ OUT_LIST+=(${CON} ${SUPPLIER})
+ RET=0
+ done
+
+ return $RET
+}
+
+function detail_compat() {
+ f=$1/of_node/compatible
+ if [ -e $f ]
+ then
+ echo -n $(cat $f)
+ else
+ echo -n $1
+ fi
+}
+
+function detail_module() {
+ f=$1/driver/module
+ if [ -e $f ]
+ then
+ echo -n $(basename $(realpath $f))
+ else
+ echo -n $1
+ fi
+}
+
+function detail_driver() {
+ f=$1/driver
+ if [ -e $f ]
+ then
+ echo -n $(basename $(realpath $f))
+ else
+ echo -n $1
+ fi
+}
+
+function detail_fwnode() {
+ f=$1/firmware_node
+ if [ ! -e $f ]
+ then
+ f=$1/of_node
+ fi
+
+ if [ -e $f ]
+ then
+ echo -n $(realpath $f)
+ else
+ echo -n $1
+ fi
+}
+
+function detail_graphviz() {
+ if [ "$2" != "ROOT" ]
+ then
+ echo -n "\"$(basename $2)\"->\"$(basename $1)\""
+ else
+ echo -n "\"$(basename $1)\""
+ fi
+}
+
+function detail_tsort() {
+ echo -n "\"$2\" \"$1\""
+}
+
+function detail_device() { echo -n $1; }
+
+alias detail=detail_device
+ALLOW_NO_DRIVER=0
+ALLOW_DEVLINKS=1
+ALLOW_PARENTS=1
+
+while [ $# -gt 0 ]
+do
+ ARG=$1
+ case $ARG in
+ --help)
+ help
+ exit 0
+ ;;
+ -c)
+ alias detail=detail_compat
+ ;;
+ -m)
+ alias detail=detail_module
+ ;;
+ -d)
+ alias detail=detail_driver
+ ;;
+ -f)
+ alias detail=detail_fwnode
+ ;;
+ -g)
+ alias detail=detail_graphviz
+ ;;
+ -t)
+ alias detail=detail_tsort
+ ;;
+ --allow-no-driver)
+ ALLOW_NO_DRIVER=1
+ ;;
+ --exclude-devlinks)
+ ALLOW_DEVLINKS=0
+ ;;
+ --exclude-parents)
+ ALLOW_PARENTS=0
+ ;;
+ *)
+ # Stop at the first argument that's not an option.
+ break
+ ;;
+ esac
+ shift
+done
+
+function detail_chosen() {
+ detail $1 $2
+}
+
+if [ $# -eq 0 ]
+then
+ help
+ exit 1
+fi
+
+CONSUMERS=($@)
+OUT_LIST=()
+
+# Do a breadth first, non-recursive tracking of suppliers. The parent is also
+# considered a "supplier" as a device can't probe without its parent.
+i=0
+while [ $i -lt ${#CONSUMERS[@]} ]
+do
+ CONSUMER=$(realpath ${CONSUMERS[$i]})
+ i=$(($i+1))
+
+ if already_seen ${CONSUMER}
+ then
+ continue
+ fi
+
+ # If this is not a device with a driver, we don't care about its
+ # suppliers.
+ if [ ! -e ${CONSUMER}/driver -a ${ALLOW_NO_DRIVER} -eq 0 ]
+ then
+ continue
+ fi
+
+ ROOT=1
+
+ # Add suppliers to CONSUMERS list and output the consumer details.
+ #
+ # We don't need to worry about a cycle in the dependency chain causing
+ # infinite loops. That's because the kernel doesn't allow cycles in
+ # device links unless it's a sync_state_only device link. And we ignore
+ # sync_state_only device links inside add_suppliers.
+ if add_suppliers ${CONSUMER}
+ then
+ ROOT=0
+ fi
+
+ if add_parent ${CONSUMER}
+ then
+ ROOT=0
+ fi
+
+ if [ $ROOT -eq 1 ]
+ then
+ OUT_LIST+=(${CONSUMER} "ROOT")
+ fi
+done
+
+# Can NOT combine sort and uniq using sort -suk2 because stable sort in toybox
+# isn't really stable.
+dev_to_detail | sort -k2 -k1 | uniq -f 1 | sort | cut -f2-
+
+exit 0
projects / platform / kernel / linux-rpi.git / commitdiff