iio: accel: kxcjk-1013: Implement ACPI method ROTM to retrieve mount matrix.

Implement kxj_acpi_orientation to retrieve mount matrix
from ACPI ROTM method

Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sean Rhodes <sean@starlabs.systems>
Link: https://lore.kernel.org/r/19d7a10aae5238a2c8db37da1f74edb86480e17e.1708293140.git.sean@starlabs.systemsSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/accel/kxcjk-1013.c

@@ -636,6 +636,84 @@ static int kxcjk1013_set_power_state(struct kxcjk1013_data *data, bool on)
 	return 0;
 }
 
+#ifdef CONFIG_ACPI
+static bool kxj_acpi_orientation(struct device *dev,
+				 struct iio_mount_matrix *orientation)
+{
+	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 (!acpi_has_method(adev->handle, "ROTM"))
+		return false;
+
+	status = acpi_evaluate_object(adev->handle, "ROTM", 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;
+}
+
+static bool kxj1009_apply_acpi_orientation(struct device *dev,
+					  struct iio_mount_matrix *orientation)
+{
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+
+	if (adev && acpi_dev_hid_uid_match(adev, "KIOX000A", NULL))
+		return kxj_acpi_orientation(dev, orientation);
+
+	return false;
+}
+#else
+static bool kxj1009_apply_acpi_orientation(struct device *dev,
+					  struct iio_mount_matrix *orientation)
+{
+	return false;
+}
+#endif
+
 static int kxcjk1013_chip_update_thresholds(struct kxcjk1013_data *data)
 {
 	int ret;
@@ -1466,11 +1544,14 @@ static int kxcjk1013_probe(struct i2c_client *client)
 	} else {
 		data->active_high_intr = true; /* default polarity */
 
+		if (!kxj1009_apply_acpi_orientation(&client->dev, &data->orientation)) {
 			ret = iio_read_mount_matrix(&client->dev, &data->orientation);
 			if (ret)
 				return ret;
 		}
 
+	}
+
 	ret = devm_regulator_bulk_get_enable(&client->dev,
 					     ARRAY_SIZE(regulator_names),
 					     regulator_names);