udev: builtin-keyboard: add support for EVDEV_ABS_*

Parse properties in the form
EVDEV_ABS_00="<min>:<max>:<res>:<fuzz>:<flat>"

and apply them to the kernel device. Future processes that open that device
will see the updated EV_ABS range.

This is particularly useful for touchpads that don't provide a resolution in
the kernel driver but can be fixed up through hwdb entries (e.g. bcm5974).

All values in the property are optional, e.g. a string of "::45" is valid to
set the resolution to 45.

The order intentionally orders resolution before fuzz and flat despite it
being the last element in the absinfo struct. The use-case for setting
fuzz/flat is almost non-existent, resolution is probably the most common case
we'll need.

To avoid multiple hwdb invocations for the same device, replace the
hwdb "keyboard:" prefix with "evdev:" and drop the separate 60-keyboard.rules
file. The new 60-evdev.rules is called for all event nodes
anyway, we don't need a separate rules file and second callout to the hwdb
builtin.

1 files changed, 19 insertions, 0 deletions

diff --git a/rules/60-evdev.rules b/rules/60-evdev.rules
new file mode 100644
index 0000000000..e81966fbe8
--- /dev/null
+++ b/rules/60-evdev.rules
@@ -0,0 +1,19 @@
+# do not edit this file, it will be overwritten on update
+
+ACTION=="remove", GOTO="evdev_end"
+KERNEL!="event*", GOTO="evdev_end"
+
+# skip later rules when we find something for this input device
+IMPORT{builtin}="hwdb --subsystem=input --lookup-prefix=evdev:", \
+  RUN{builtin}+="keyboard", GOTO="evdev_end"
+
+# AT keyboard matching by the machine's DMI data
+ENV{ID_INPUT_KEY}=="?*", DRIVERS=="atkbd", \
+  IMPORT{builtin}="hwdb 'evdev:atkbd:$attr{[dmi/id]modalias}'", \
+  RUN{builtin}+="keyboard", GOTO="keyboard_end"
+
+# device matching the input device name and the machine's DMI data
+KERNELS=="input*", IMPORT{builtin}="hwdb 'evdev:name:$attr{name}:$attr{[dmi/id]modalias}'", \
+  RUN{builtin}+="keyboard", GOTO="evdev_end"
+
+LABEL="evdev_end"