Merging upstream version 6.10.3.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 85 insertions, 0 deletions

diff --git a/drivers/iio/industrialio-acpi.c b/drivers/iio/industrialio-acpi.c
new file mode 100644
index 0000000000..981b75d407
--- /dev/null
+++ b/drivers/iio/industrialio-acpi.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* IIO ACPI helper functions */
+
+#include <linux/acpi.h>
+#include <linux/dev_printk.h>
+#include <linux/iio/iio.h>
+#include <linux/sprintf.h>
+
+/**
+ * iio_read_acpi_mount_matrix() - Read accelerometer mount matrix info from ACPI
+ * @dev:		Device structure
+ * @orientation:	iio_mount_matrix struct to fill
+ * @acpi_method:	ACPI method name to read the matrix from, usually "ROTM"
+ *
+ * Try to read the mount-matrix by calling the specified method on the device's
+ * ACPI firmware-node. If the device has no ACPI firmware-node; or the method
+ * does not exist then this will fail silently. This expects the method to
+ * return data in the ACPI "ROTM" format defined by Microsoft:
+ * https://learn.microsoft.com/en-us/windows-hardware/drivers/sensors/sensors-acpi-entries
+ * This is a Microsoft extension and not part of the official ACPI spec.
+ * The method name is configurable because some dual-accel setups define 2 mount
+ * matrices in a single ACPI device using separate "ROMK" and "ROMS" methods.
+ *
+ * Returns: true if the matrix was successfully, false otherwise.
+ */
+bool iio_read_acpi_mount_matrix(struct device *dev,
+				struct iio_mount_matrix *orientation,
+				char *acpi_method)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	char *str;
+	union acpi_object *obj, *elements;
+	acpi_status status;
+	int i, j, val[3];
+	bool ret = false;
+
+	if (!adev || !acpi_has_method(adev->handle, acpi_method))
+		return false;
+
+	status = acpi_evaluate_object(adev->handle, acpi_method, NULL, &buffer);
+	if (ACPI_FAILURE(status)) {
+		dev_err(dev, "Failed to get ACPI mount matrix: %d\n", status);
+		return false;
+	}
+
+	obj = buffer.pointer;
+	if (obj->type != ACPI_TYPE_PACKAGE || obj->package.count != 3) {
+		dev_err(dev, "Unknown ACPI mount matrix package format\n");
+		goto out_free_buffer;
+	}
+
+	elements = obj->package.elements;
+	for (i = 0; i < 3; i++) {
+		if (elements[i].type != ACPI_TYPE_STRING) {
+			dev_err(dev, "Unknown ACPI mount matrix element format\n");
+			goto out_free_buffer;
+		}
+
+		str = elements[i].string.pointer;
+		if (sscanf(str, "%d %d %d", &val[0], &val[1], &val[2]) != 3) {
+			dev_err(dev, "Incorrect ACPI mount matrix string format\n");
+			goto out_free_buffer;
+		}
+
+		for (j = 0; j < 3; j++) {
+			switch (val[j]) {
+			case -1: str = "-1"; break;
+			case 0:  str = "0";  break;
+			case 1:  str = "1";  break;
+			default:
+				dev_err(dev, "Invalid value in ACPI mount matrix: %d\n", val[j]);
+				goto out_free_buffer;
+			}
+			orientation->rotation[i * 3 + j] = str;
+		}
+	}
+
+	ret = true;
+
+out_free_buffer:
+	kfree(buffer.pointer);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iio_read_acpi_mount_matrix);