From fa741e87a874da5c416352252a98d64fce2cd8a1 Mon Sep 17 00:00:00 2001
From: Boian Bonev <bbonev@ipacct.com>
Date: Thu, 22 Sep 2022 01:17:17 +0300
Subject: [PATCH 1/3] udev: hwdb: Match iio sensors based on their label

The IIO subsystem exposes a 'label' sysfs file to help userspace better
identify its devices [1]. Standardized labels include the sensor type
along with its location, including 'accel-base' and 'accel-display'.

Most Chrome OS boards have two accelerometers that are indistinguishable
except for this label (or a 'location' sysfs file before Linux v6.0),
and need different mounting matrix corrections based on their location.

Add a udev rule that matches hwdb entries using this label, so we can
correct both accelerometers on these devices with hwdb entries. The
existing rules and hwdb entries are not modified to keep potential
out-of-tree entries working, but new entries in this form will override
existing ones. Also add currently standardized labels to parse-hwdb.py.

[1] https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-bus-iio

systemd-commit e2f25ae64889ea7fe8a7556ee5fba91bc2a0eab8
Author: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Date:   Thu Aug 18 17:27:22 2022 +0300
---
 hwdb/60-sensor.hwdb   | 3 +++
 rules/60-sensor.rules | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/hwdb/60-sensor.hwdb b/hwdb/60-sensor.hwdb
index ea278913b..ecd10f292 100644
--- a/hwdb/60-sensor.hwdb
+++ b/hwdb/60-sensor.hwdb
@@ -9,10 +9,13 @@
 # ABI.
 #
 # Match string formats:
+# sensor:<label>:modalias:<parent modalias pattern>:dmi:<dmi pattern>
 # sensor:modalias:<parent modalias pattern>:dmi:<dmi pattern>
 #
 # The device modalias can be seen in the `modalias` file of the sensor parent,
+# and the device label can be seen in the `label` file of the sensor,
 # for example:
+#   cat /sys/`udevadm info -q path -n /dev/iio:device0`/label
 #   cat /sys/`udevadm info -q path -n /dev/iio:device0`/../modalias
 #
 # The full DMI string of the running machine can be read from
diff --git a/rules/60-sensor.rules b/rules/60-sensor.rules
index 7b9b7d288..99b8f5fc7 100644
--- a/rules/60-sensor.rules
+++ b/rules/60-sensor.rules
@@ -2,6 +2,11 @@
 
 ACTION=="remove", GOTO="sensor_end"
 
+# device matching the sensor's label, name and the machine's DMI data for IIO devices
+SUBSYSTEM=="iio", KERNEL=="iio*", SUBSYSTEMS=="usb|i2c|platform", ATTR{label}!="", \
+  IMPORT{builtin}="hwdb 'sensor:$attr{label}:modalias:$attr{modalias}:$attr{[dmi/id]modalias}'", \
+  GOTO="sensor_end"
+
 # device matching the sensor's name and the machine's DMI data for IIO devices
 SUBSYSTEM=="iio", KERNEL=="iio*", SUBSYSTEMS=="usb|i2c|platform", \
   IMPORT{builtin}="hwdb 'sensor:modalias:$attr{modalias}:$attr{[dmi/id]modalias}'", \

From 9f366b943de79689123e6d875e0fb08f8c60724d Mon Sep 17 00:00:00 2001
From: Boian Bonev <bbonev@ipacct.com>
Date: Thu, 22 Sep 2022 01:28:34 +0300
Subject: [PATCH 2/3] hwdb: Add Chromebook accel orientation quirks based on
 sysfs label

The base-mounted accelerometer on Chromebooks return values same as the
display when the lid angle is 180 degrees, instead of when the lid is
closed. To match userspace expectations we must further rotate the
existing accelerometer mounting matrix by 180 degrees around the X axis:

    [[-1,  0,  0],    [[ 1,  0,  0],    [[-1,  0,  0],
     [ 0, -1,  0],  X  [ 0, -1,  0],  =  [ 0,  1,  0],
     [ 0,  0, -1]]     [ 0,  0, -1]]     [ 0,  0,  1]]

A previous commit lets us distinguish between the two cros-ec-accel
devices on these boards by their 'label' sysfs file. Add hwdb entries
that make base-mounted accelerometers use this correct matrix, and
display-mounted ones use the existing one.

Note that the cros-ec-accel drivers use 'label' only since Linux v6.0.
The old match strings are not removed to support older kernels, even
though they are only correct for the display-mounted sensor.

systemd-commit fea267f8c71d0edffee5ccbb806755fb626c5e29
Author: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Date:   Thu Aug 18 18:24:05 2022 +0300
---
 hwdb/60-sensor.hwdb | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/hwdb/60-sensor.hwdb b/hwdb/60-sensor.hwdb
index ecd10f292..f1a068106 100644
--- a/hwdb/60-sensor.hwdb
+++ b/hwdb/60-sensor.hwdb
@@ -402,6 +402,17 @@ sensor:modalias:platform:cros-ec-accel:dmi:*svnGoogle:pnVayne*:*
 sensor:modalias:platform:cros-ec-accel:dmi:*Google_Nocturne*:*
  ACCEL_MOUNT_MATRIX=1, 0, 0; 0, -1, 0; 0, 0, 1
 
+sensor:modalias:platform:cros-ec-accel:*
+sensor:accel-display:modalias:platform:cros-ec-accel:*
+sensor:accel-display:modalias:platform:cros-ec-accel-legacy:*
+ ACCEL_MOUNT_MATRIX=-1, 0, 0; 0, -1, 0; 0, 0, -1
+
+# Base accel reports the same as display when lid angle is 180 degrees (vs 0),
+# so it needs an additional 180 degree rotation around the X axis.
+sensor:accel-base:modalias:platform:cros-ec-accel:*
+sensor:accel-base:modalias:platform:cros-ec-accel-legacy:*
+ ACCEL_MOUNT_MATRIX=-1, 0, 0; 0, 1, 0; 0, 0, 1
+
 #########################################
 # GP-electronic
 #########################################

From 152456e741284c43cc044a80afcf3400e8f96cd3 Mon Sep 17 00:00:00 2001
From: Boian Bonev <bbonev@ipacct.com>
Date: Thu, 22 Sep 2022 01:29:51 +0300
Subject: [PATCH 3/3] udev: hwdb: Add rules to match cros-ec-accel by
 'location' sysfs file

The cros-ec-accel devices report their mounting location by the 'label'
sysfs file only since Linux v6.0. With earlier kernels, a nonstandard
'location' file reports this, but slightly differently (lid instead of
display) [1].

Add udev rules to import the correct hwdb entries based on this
'location' file for cros-ec-accel devices, so that the base-mounted
accel matrix has the correct value for older kernels as well.

[1] https://kernel.org/doc/Documentation/ABI/testing/sysfs-bus-iio-cros-ec

systemd-commit ac3c031e3862e3d74e64b108e0bafcaefa71c792
Author: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Date:   Thu Aug 18 19:56:13 2022 +0300
---
 rules/60-sensor.rules | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/rules/60-sensor.rules b/rules/60-sensor.rules
index 99b8f5fc7..09180b4b2 100644
--- a/rules/60-sensor.rules
+++ b/rules/60-sensor.rules
@@ -7,6 +7,17 @@ SUBSYSTEM=="iio", KERNEL=="iio*", SUBSYSTEMS=="usb|i2c|platform", ATTR{label}!="
   IMPORT{builtin}="hwdb 'sensor:$attr{label}:modalias:$attr{modalias}:$attr{[dmi/id]modalias}'", \
   GOTO="sensor_end"
 
+# Before Linux v6.0, cros-ec-accel used a non-standard 'location' sysfs file
+SUBSYSTEM=="iio", KERNEL=="iio*", SUBSYSTEMS=="platform", \
+  ATTR{name}=="cros-ec-accel|cros-ec-accel-legacy", ATTR{location}=="base", \
+  IMPORT{builtin}="hwdb 'sensor:accel-base:modalias:$attr{modalias}:$attr{[dmi/id]modalias}'", \
+  GOTO="sensor_end"
+
+SUBSYSTEM=="iio", KERNEL=="iio*", SUBSYSTEMS=="platform", \
+  ATTR{name}=="cros-ec-accel|cros-ec-accel-legacy", ATTR{location}=="lid", \
+  IMPORT{builtin}="hwdb 'sensor:accel-display:modalias:$attr{modalias}:$attr{[dmi/id]modalias}'", \
+  GOTO="sensor_end"
+
 # device matching the sensor's name and the machine's DMI data for IIO devices
 SUBSYSTEM=="iio", KERNEL=="iio*", SUBSYSTEMS=="usb|i2c|platform", \
   IMPORT{builtin}="hwdb 'sensor:modalias:$attr{modalias}:$attr{[dmi/id]modalias}'", \