hwdb: add a 70-touchpad.hwdb to tag internal vs external touchpads

Add a new key ID_INPUT_TOUCHPAD_INTEGRATION=internal|external so we have a
single source for figuring out which touchpads are built-in.

Fairly simple approach: bluetooth is external, usb is external unless it's an
Apple touchpad. Everything else is internal.

Makefile.am

@@ -3667,6 +3667,7 @@ dist_udevrules_DATA += \
 	rules/60-serial.rules \
 	rules/64-btrfs.rules \
 	rules/70-mouse.rules \
+	rules/70-touchpad.rules \
 	rules/75-net-description.rules \
 	rules/78-sound-card.rules \
 	rules/80-net-setup-link.rules
@@ -3833,7 +3834,8 @@ dist_udevhwdb_DATA = \
 	hwdb/60-evdev.hwdb \
 	hwdb/60-keyboard.hwdb \
 	hwdb/70-mouse.hwdb \
-	hwdb/70-pointingstick.hwdb
+	hwdb/70-pointingstick.hwdb \
+	hwdb/70-touchpad.hwdb
 
 SYSINIT_TARGET_WANTS += \
 	systemd-hwdb-update.service

hwdb/70-touchpad.hwdb

@@ -0,0 +1,49 @@
+# This file is part of systemd.
+#
+# Database for touchpad device information that cannot be queried directly.
+#
+# The lookup keys are composed in:
+#   70-touchpad.rules
+#
+# Note: The format of the "touchpad:" prefix match key is a
+# contract between the rules file and the hardware data, it might
+# change in later revisions to support more or better matches, it
+# is not necessarily expected to be a stable ABI.
+#
+# Match string format:
+# touchpad:<subsystem>:v<vid>p<pid>:name:<name>:
+#
+# vid/pid as 4-digit hex lowercase vendor/product
+#
+# To add local entries, create a new file
+#   /etc/udev/hwdb.d/71-touchpad-local.hwdb
+# and add your rules there. To load the new rules execute (as root):
+#   udevadm hwdb --update
+#   udevadm trigger /dev/input/eventXX
+# where /dev/input/eventXX is the touchpad in question. If in
+# doubt, simply use /dev/input/event* to reload all input rules.
+#
+# If your changes are generally applicable, preferably send them as a pull
+# request to
+#   https://github.com/systemd/systemd
+# or create a bug report on https://github.com/systemd/systemd/issues and
+# include your new rules, a description of the device, and the output of
+#   udevadm info /dev/input/eventXX.
+#
+# Permitted keys:
+#   Specify if a touchpad is a built-in one or external:
+#   ID_INPUT_TOUCHPAD_INTEGRATION=internal|external
+
+touchpad:i8042:*
+touchpad:rmi:*
+ ID_INPUT_TOUCHPAD_INTEGRATION=internal
+
+touchpad:bluetooth:*
+touchpad:usb:*
+ ID_INPUT_TOUCHPAD_INTEGRATION=external
+
+###########################################################
+# Apple
+###########################################################
+touchpad:usb:v05ac*
+ ID_INPUT_TOUCHPAD_INTEGRATION=internal

rules/70-touchpad.rules

@@ -0,0 +1,13 @@
+# do not edit this file, it will be overwritten on update
+
+ACTION=="remove", GOTO="touchpad_end"
+ENV{ID_INPUT}=="", GOTO="touchpad_end"
+ENV{ID_INPUT_TOUCHPAD}=="", GOTO="touchpad_end"
+KERNEL!="event*", GOTO="touchpad_end"
+
+# touchpad:<subsystem>:v<vid>p<pid>:name:<name>:*
+KERNELS=="input*", ENV{ID_BUS}!="", \
+        IMPORT{builtin}="hwdb 'touchpad:$env{ID_BUS}:v$attr{id/vendor}p$attr{id/product}:name:$attr{name}:'", \
+        GOTO="touchpad_end"
+
+LABEL="touchpad_end"