new file mode 100644
@@ -0,0 +1,83 @@
+/* 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
+/*
+ * Parse mount matrices defined in the ACPI "ROTM" format from:
+ * 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.
+ */
+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
@@ -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;
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> --- Changes in v2: - Add comment about the Microsoft specification for the "ROTM" ACPI method --- drivers/iio/accel/acpi-helpers.h | 83 ++++++++++++++++++++++++++++++++ drivers/iio/accel/kxcjk-1013.c | 71 ++------------------------- 2 files changed, 86 insertions(+), 68 deletions(-) create mode 100644 drivers/iio/accel/acpi-helpers.h