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. Add an iio_read_acpi_mount_matrix() helper function for this. The 2 existing copies of the code are identical, except that the kxcjk-1013.c has slightly better error logging. To new helper is a 1:1 copy of the kxcjk-1013.c version, the only change is the addition of a "char *acpi_method" parameter since some bmc150 dual-accel setups (360° hinges with 1 accel in kbd/base + 1 in display) declare both accels in a single ACPI device with 2 different method names for the 2 matrices. This new acpi_method parameter is not "const char *" because the pathname parameter to acpi_evaluate_object() is not const. The 2 existing copies of this function will be removed in further patches in this series. Acked-by: Rafael J. Wysocki <rafael@xxxxxxxxxx> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- Changes in v3: - New patch in v3 of this series. --- drivers/iio/Makefile | 1 + drivers/iio/industrialio-acpi.c | 85 +++++++++++++++++++++++++++++++++ include/linux/iio/iio.h | 13 +++++ 3 files changed, 99 insertions(+) create mode 100644 drivers/iio/industrialio-acpi.c diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile index 0ba0e1521ba4..cb80ef837e84 100644 --- a/drivers/iio/Makefile +++ b/drivers/iio/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_IIO) += industrialio.o industrialio-y := industrialio-core.o industrialio-event.o inkern.o industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o +industrialio-$(CONFIG_ACPI) += industrialio-acpi.o obj-$(CONFIG_IIO_CONFIGFS) += industrialio-configfs.o obj-$(CONFIG_IIO_GTS_HELPER) += industrialio-gts-helper.o diff --git a/drivers/iio/industrialio-acpi.c b/drivers/iio/industrialio-acpi.c new file mode 100644 index 000000000000..c47bf0c22e4f --- /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 + * @matrix: iio_mount_matrix struct to fill + * @method_name: 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); diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h index e370a7bb3300..4ed41e70c86e 100644 --- a/include/linux/iio/iio.h +++ b/include/linux/iio/iio.h @@ -788,6 +788,19 @@ static inline struct dentry *iio_get_debugfs_dentry(struct iio_dev *indio_dev) } #endif +#ifdef CONFIG_ACPI +bool iio_read_acpi_mount_matrix(struct device *dev, + struct iio_mount_matrix *matrix, + char *method_name); +#else +static inline bool iio_read_acpi_mount_matrix(struct device *dev, + struct iio_mount_matrix *matrix, + char *method_name) +{ + return false; +} +#endif + ssize_t iio_format_value(char *buf, unsigned int type, int size, int *vals); int iio_str_to_fixpoint(const char *str, int fract_mult, int *integer, -- 2.44.0
