pmaports/temp/iio-sensor-proxy/299.patch

From c94f5d31250f9cc75271a7f386104ce2fdfb268e Mon Sep 17 00:00:00 2001
From: Dmitry Osipenko <digetx@gmail.com>
Date: Sat, 18 Jan 2020 19:29:08 +0300
Subject: [PATCH] mount-matrix: Support IIO sysfs matrices

Linux kernel IIO drivers provide mount matrix via standardized sysfs
interface, let's support these drivers. Tested on Nexus 7 and Acer A500
tablet devices using MPU6050 and KXTF9 IIO drivers respectively, now
monitor-sensor reports display's orientation correctly on these devices.
---
 src/accel-mount-matrix.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/src/accel-mount-matrix.c b/src/accel-mount-matrix.c
index c66b440..ced2819 100644
--- a/src/accel-mount-matrix.c
+++ b/src/accel-mount-matrix.c
@@ -50,6 +50,42 @@ setup_mount_matrix (GUdevDevice *device)
 		g_clear_pointer (&ret, g_free);
 	}
 
+	/*
+	 * Linux kernel IIO accelerometer drivers provide mount matrix
+	 * via standardized sysfs interface.
+	 *
+	 * See https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-bus-iio
+	 * for more details.
+	 */
+	mount_matrix = g_udev_device_get_sysfs_attr (device, "in_mount_matrix");
+	if (mount_matrix) {
+		if (parse_mount_matrix (mount_matrix, &ret))
+			return ret;
+
+		g_warning ("Failed to parse in_mount_matrix ('%s') from sysfs",
+			   mount_matrix);
+		g_clear_pointer (&ret, g_free);
+	}
+
+	/*
+	 * Some IIO drivers provide multiple sensors via the same sysfs path
+	 * and thus they may have different matrices like in a case of
+	 * accelerometer and angular velocity for example. The accelerometer
+	 * mount matrix is named as in_accel_mount_matrix in that case.
+	 *
+	 * See https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-bus-iio
+	 * for more details.
+	 */
+	mount_matrix = g_udev_device_get_sysfs_attr (device, "in_accel_mount_matrix");
+	if (mount_matrix) {
+		if (parse_mount_matrix (mount_matrix, &ret))
+			return ret;
+
+		g_warning ("Failed to parse in_accel_mount_matrix ('%s') from sysfs",
+			   mount_matrix);
+		g_clear_pointer (&ret, g_free);
+	}
+
 	g_debug ("Failed to auto-detect mount matrix, falling back to identity");
 	parse_mount_matrix (NULL, &ret);
 	return ret;
-- 
2.24.1