[PATCH 2/4] iio: accel: kxcjk-1013: Move ACPI ROTM parsing to new acpi-helpers.h

[Hans de Goede <hdegoede@redhat.com>]

The ACPI "ROTM" rotation matrix parsing code atm is already duplicated
between bmc150-accel-core.c and kxcjk-1013.c and a third user of this is
coming.

Move the ROTM parsing from kxcjk-1013.c, which has slightly better error
logging (and otherwise is 100% identical), into a new acpi-helpers.h file
so that it can be shared.

Other then moving the code the only 2 other changes are:

1. Rename the function to acpi_read_mount_matrix() to make clear this
   is a generic ACPI mount matrix read function.
2. Add a "char *acpi_method" parameter since some bmc150 dual-accel setups
   (360° hinges with 1 accel in kbd/base + 1 in display half) declare both
   accels in a single ACPI device with 2 different method names for
   the 2 matrices.

Cc: Sean Rhodes <sean@starlabs.systems>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/iio/accel/acpi-helpers.h | 76 ++++++++++++++++++++++++++++++++
 drivers/iio/accel/kxcjk-1013.c   | 71 ++---------------------------
 2 files changed, 79 insertions(+), 68 deletions(-)
 create mode 100644 drivers/iio/accel/acpi-helpers.h

diff --git a/drivers/iio/accel/acpi-helpers.h b/drivers/iio/accel/acpi-helpers.h
new file mode 100644
index 000000000000..a4357925bf07
--- /dev/null
+++ b/drivers/iio/accel/acpi-helpers.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* ACPI helper functions for parsing ACPI rotation matrices */
+
+#include <linux/acpi.h>
+#include <linux/dev_printk.h>
+#include <linux/iio/iio.h>
+#include <linux/sprintf.h>
+
+#ifdef CONFIG_ACPI
+static inline bool acpi_read_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;
+}
+#else
+static inline bool acpi_read_mount_matrix(struct device *dev,
+					  struct iio_mount_matrix *orientation,
+					  char *acpi_method)
+{
+	return false;
+}
+#endif
diff --git a/drivers/iio/accel/kxcjk-1013.c b/drivers/iio/accel/kxcjk-1013.c
index bb1660667bb0..7e19278491dc 100644
--- a/drivers/iio/accel/kxcjk-1013.c
+++ b/drivers/iio/accel/kxcjk-1013.c
@@ -24,6 +24,8 @@
 #include <linux/iio/triggered_buffer.h>
 #include <linux/iio/accel/kxcjk_1013.h>
 
+#include "acpi-helpers.h"
+
 #define KXCJK1013_DRV_NAME "kxcjk1013"
 #define KXCJK1013_IRQ_NAME "kxcjk1013_event"
 
@@ -636,73 +638,6 @@ static int kxcjk1013_set_power_state(struct kxcjk1013_data *data, bool on)
 	return 0;
 }
 
-#ifdef CONFIG_ACPI
-static bool kxj1009_apply_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 (!adev || !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;
-}
-#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;
@@ -1533,7 +1468,7 @@ 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)) {
+		if (!acpi_read_mount_matrix(&client->dev, &data->orientation, "ROTM")) {
 			ret = iio_read_mount_matrix(&client->dev, &data->orientation);
 			if (ret)
 				return ret;
-- 
2.44.0