iio: accel: bmc150: Set label based on accel-location on 2-accel yoga-style 2-in-1s

Some 2-in-1 laptops / convertibles with 360° (yoga-style) hinges,
use 2 bmc150 accelerometers, defined by a single BOSC0200 ACPI
device node (1 in their base and 1 in their display).

Since in this case we know the location of each accelerometer,
set the label for the accelerometers to the standardized
"accel-display" resp. "accel-base" labels. This way userspace
can use the labels to get the location.

This was tested on a Lenovo ThinkPad Yoga 11e 4th gen (N3450 CPU).
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210207160901.110643-3-hdegoede@redhat.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/bmc150-accel-core.c

@@ -443,26 +443,32 @@ static bool bmc150_apply_acpi_orientation(struct device *dev,
 					  struct iio_mount_matrix *orientation)
 {
 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct acpi_device *adev = ACPI_COMPANION(dev);
+	char *name, *alt_name, *label, *str;
 	union acpi_object *obj, *elements;
-	char *name, *alt_name, *str;
 	acpi_status status;
 	int i, j, val[3];
 
 	if (!adev || !acpi_dev_hid_uid_match(adev, "BOSC0200", NULL))
 		return false;
 
-	if (strcmp(dev_name(dev), "i2c-BOSC0200:base") == 0)
+	if (strcmp(dev_name(dev), "i2c-BOSC0200:base") == 0) {
 		alt_name = "ROMK";
-	else
+		label = "accel-base";
+	} else {
 		alt_name = "ROMS";
+		label = "accel-display";
+	}
 
-	if (acpi_has_method(adev->handle, "ROTM"))
+	if (acpi_has_method(adev->handle, "ROTM")) {
 		name = "ROTM";
-	else if (acpi_has_method(adev->handle, alt_name))
+	} else if (acpi_has_method(adev->handle, alt_name)) {
 		name = alt_name;
-	else
+		indio_dev->label = label;
+	} else {
 		return false;
+	}
 
 	status = acpi_evaluate_object(adev->handle, name, NULL, &buffer);
 	if (ACPI_FAILURE(status)) {