Re: [PATCH v3 3/4] platform/x86: Add Lenovo Capability Data 01 WMI Driver

Derek John Clark
2025-03-16T17:00:33Z

On Tue, Mar 11, 2025 at 1:34 PM Armin Wolf <W_Armin@gmx.de> wrote:
>
> Am 10.03.25 um 23:26 schrieb Derek John Clark:
>
> > On Fri, Mar 7, 2025 at 3:05 PM Armin Wolf <W_Armin@gmx.de> wrote:
> >> Am 25.02.25 um 22:59 schrieb Derek J. Clark:
> >>
> >>> Adds lenovo-wmi-capdata01.c which provides a driver for the
> >>> LENOVO_CAPABILITY_DATA_01 WMI data block that comes on "Other Mode"
> >>> enabled hardware. Provides an interface for querying if a given
> >>> attribute is supported by the hardware, as well as its default_value,
> >>> max_value, min_value, and step increment.
> >>> v3:
> >>> - Add as component to lenovo-wmi-other driver.
> >>> v2:
> >>> - Use devm_kmalloc to ensure driver can be instanced, remove global
> >>> reference.
> >>> - Ensure reverse Christmas tree for all variable declarations.
> >>> - Remove extra whitespace.
> >>> - Use guard(mutex) in all mutex instances, global mutex.
> >>> - Use pr_fmt instead of adding the driver name to each pr_err.
> >>> - Remove noisy pr_info usage.
> >>> - Rename capdata_wmi to lenovo_wmi_cd01_priv and cd01_wmi to priv.
> >>> - Use list to get the lenovo_wmi_cd01_priv instance in
> >>> lenovo_wmi_capdata01_get as none of the data provided by the macros
> >>> that will use it can pass a member of the struct for use in
> >>> container_of.
> >>>
> >>> Signed-off-by: Derek J. Clark <derekjohn.clark@gmail.com>
> >>> ---
> >>> MAINTAINERS | 1 +
> >>> drivers/platform/x86/Kconfig | 5 +
> >>> drivers/platform/x86/Makefile | 1 +
> >>> drivers/platform/x86/lenovo-wmi-capdata01.c | 140 ++++++++++++++++++++
> >>> drivers/platform/x86/lenovo-wmi.h | 19 +++
> >>> 5 files changed, 166 insertions(+)
> >>> create mode 100644 drivers/platform/x86/lenovo-wmi-capdata01.c
> >>>
> >>> diff --git a/MAINTAINERS b/MAINTAINERS
> >>> index cf7f4fce1a25..f6d3e79e50ce 100644
> >>> --- a/MAINTAINERS
> >>> +++ b/MAINTAINERS
> >>> @@ -13157,6 +13157,7 @@ L: platform-driver-x86@vger.kernel.org
> >>> S: Maintained
> >>> F: Documentation/wmi/devices/lenovo-wmi-gamezone.rst
> >>> F: Documentation/wmi/devices/lenovo-wmi-other.rst
> >>> +F: drivers/platform/x86/lenovo-wmi-capdata01.c
> >>> F: drivers/platform/x86/lenovo-wmi-gamezone.c
> >>> F: drivers/platform/x86/lenovo-wmi.c
> >>> F: drivers/platform/x86/lenovo-wmi.h
> >>> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> >>> index 875822e6bd65..56336dc3c2d0 100644
> >>> --- a/drivers/platform/x86/Kconfig
> >>> +++ b/drivers/platform/x86/Kconfig
> >>> @@ -475,6 +475,11 @@ config LENOVO_WMI_GAMEZONE
> >>> To compile this driver as a module, choose M here: the module will
> >>> be called lenovo-wmi-gamezone.
> >>>
> >>> +config LENOVO_WMI_DATA01
> >>> + tristate
> >>> + depends on ACPI_WMI
> >>> + select LENOVO_WMI
> >>> +
> >>> config IDEAPAD_LAPTOP
> >>> tristate "Lenovo IdeaPad Laptop Extras"
> >>> depends on ACPI
> >>> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> >>> index 4a7b2d14eb82..be9031bea090 100644
> >>> --- a/drivers/platform/x86/Makefile
> >>> +++ b/drivers/platform/x86/Makefile
> >>> @@ -70,6 +70,7 @@ obj-$(CONFIG_YT2_1380) += lenovo-yoga-tab2-pro-1380-fastcharger.o
> >>> obj-$(CONFIG_LENOVO_WMI) += lenovo-wmi.o
> >>> obj-$(CONFIG_LENOVO_WMI_CAMERA) += lenovo-wmi-camera.o
> >>> obj-$(CONFIG_LENOVO_WMI_GAMEZONE) += lenovo-wmi-gamezone.o
> >>> +obj-$(CONFIG_LENOVO_WMI_DATA01) += lenovo-wmi-capdata01.o
> >>>
> >>> # Intel
> >>> obj-y += intel/
> >>> diff --git a/drivers/platform/x86/lenovo-wmi-capdata01.c b/drivers/platform/x86/lenovo-wmi-capdata01.c
> >>> new file mode 100644
> >>> index 000000000000..0fe156d5d770
> >>> --- /dev/null
> >>> +++ b/drivers/platform/x86/lenovo-wmi-capdata01.c
> >>> @@ -0,0 +1,140 @@
> >>> +// SPDX-License-Identifier: GPL-2.0-or-later
> >>> +/*
> >>> + * LENOVO_CAPABILITY_DATA_01 WMI data block driver. This interface provides
> >>> + * information on tunable attributes used by the "Other Mode" WMI interface,
> >>> + * including if it is supported by the hardware, the default_value, max_value,
> >>> + * min_value, and step increment.
> >>> + *
> >>> + * Copyright(C) 2024 Derek J. Clark <derekjohn.clark@gmail.com>
> >> 2025
> > Acked for all as Mario suggested.
> >
> >>> + */
> >>> +
> >>> +#include <linux/cleanup.h>
> >>> +#include <linux/component.h>
> >>> +#include <linux/container_of.h>
> >>> +#include <linux/device.h>
> >>> +#include <linux/gfp_types.h>
> >>> +#include <linux/types.h>
> >>> +#include <linux/wmi.h>
> >>> +#include "lenovo-wmi.h"
> >>> +
> >>> +/* Interface GUIDs */
> >>> +#define LENOVO_CAPABILITY_DATA_01_GUID "7A8F5407-CB67-4D6E-B547-39B3BE018154"
> >>> +
> >>> +static int lenovo_cd01_component_bind(struct device *cd01_dev,
> >>> + struct device *om_dev, void *data)
> >>> +{
> >>> + struct lenovo_wmi_cd01 *cd01 = dev_get_drvdata(cd01_dev);
> >>> + struct lenovo_wmi_om *om = dev_get_drvdata(om_dev);
> >> Why not using the *data pointer to pass the cd01 data? This way the capdata driver
> >> does not need to know the structure of the private data of the lenovo-wmi-other driver.
> >>
> > I can do that, sure. Seems preferable TBH as it allows me to call it priv again.
> >
> >>> +
> >>> + om->cd01 = cd01;
> >>> + return 0;
> >>> +}
> >>> +
> >>> +static void lenovo_cd01_component_unbind(struct device *cd01_dev,
> >>> + struct device *om_dev, void *data)
> >>> +
> >>> +{
> >>> + struct wmi_device *om_wdev =
> >>> + container_of(om_dev, struct wmi_device, dev);
> >>> + struct lenovo_wmi_om *om =
> >>> + container_of(&om_wdev, struct lenovo_wmi_om, wdev);
> >>> +
> >>> + om->cd01 = NULL;
> >> I think this is unnecessary, please remove the unbind callback.
> >>
> > Acked.
> >
> >>> +}
> >>> +
> >>> +static const struct component_ops lenovo_cd01_component_ops = {
> >>> + .bind = lenovo_cd01_component_bind,
> >>> + .unbind = lenovo_cd01_component_unbind,
> >>> +};
> >>> +
> >>> +static int lenovo_wmi_cd01_setup(struct lenovo_wmi_cd01 *cd01)
> >>> +{
> >>> + size_t cd_size = sizeof(struct capdata01);
> >>> + int count, idx;
> >>> +
> >>> + count = wmidev_instance_count(cd01->wdev);
> >>> +
> >>> + cd01->capdata = devm_kmalloc_array(&cd01->wdev->dev, (size_t)count,
> >>> + sizeof(*cd01->capdata), GFP_KERNEL);
> >> Cast to size_t is unnecessary here.
> >>
> > Acked.
> >
> >>> + if (!cd01->capdata)
> >>> + return -ENOMEM;
> >>> +
> >>> + cd01->instance_count = count;
> >>> +
> >>> + for (idx = 0; idx < count; idx++) {
> >>> + union acpi_object *ret_obj __free(kfree) = NULL;
> >> I am not sure if the compiler frees ret_obj after each loop iteration. Did you test this?
> >>
> > No, but I'm not sure how I would. I was manually using kfree before
> > but was asked to change to the free macro in an earlier rev.
>
> When loading this driver on you machine you can use kmemleak (https://docs.kernel.org/dev-tools/kmemleak.html)
> to detect memory leaks. If no leaks are detected then ret_obj is likely freed after each iteration and you
> can keep using __free().
>
> Thanks,
> Armin Wolf
>

No leaks were detected. I'll leave this in for v4.

Thanks,
Derek

> >
> >>> + struct capdata01 *cap_ptr =
> >>> + devm_kmalloc(&cd01->wdev->dev, cd_size, GFP_KERNEL);
> >> Please call devm_kmalloc() on a separate line.
> >>
> > Acked.
> >
> >>> + ret_obj = wmidev_block_query(cd01->wdev, idx);
> >>> + if (!ret_obj)
> >>> + continue;
> >>> +
> >>> + if (ret_obj->type != ACPI_TYPE_BUFFER)
> >>> + continue;
> >>> +
> >>> + if (ret_obj->buffer.length != cd_size)
> >>> + continue;
> >>> +
> >>> + memcpy(cap_ptr, ret_obj->buffer.pointer,
> >>> + ret_obj->buffer.length);
> >> Using devm_kmemdup() would make sense here.
> >>
> > That's a cool function. Ty, I'll use it
> >
> >>> + cd01->capdata[idx] = cap_ptr;
> >>> + }
> >>> + return 0;
> >>> +}
> >>> +
> >>> +static int lenovo_wmi_cd01_probe(struct wmi_device *wdev, const void *context)
> >>> +
> >>> +{
> >>> + struct lenovo_wmi_cd01 *cd01;
> >>> + int ret;
> >>> +
> >>> + cd01 = devm_kzalloc(&wdev->dev, sizeof(*cd01), GFP_KERNEL);
> >>> + if (!cd01)
> >>> + return -ENOMEM;
> >>> +
> >>> + cd01->wdev = wdev;
> >>> +
> >>> + ret = lenovo_wmi_cd01_setup(cd01);
> >>> + if (ret)
> >>> + return ret;
> >>> +
> >>> + dev_set_drvdata(&wdev->dev, cd01);
> >>> +
> >>> + ret = component_add(&wdev->dev, &lenovo_cd01_component_ops);
> >>> +
> >>> + return ret;
> >>> +}
> >>> +
> >>> +static void lenovo_wmi_cd01_remove(struct wmi_device *wdev)
> >>> +{
> >>> + component_del(&wdev->dev, &lenovo_cd01_component_ops);
> >>> +}
> >>> +
> >>> +static const struct wmi_device_id lenovo_wmi_cd01_id_table[] = {
> >>> + { LENOVO_CAPABILITY_DATA_01_GUID, NULL },
> >>> + {}
> >>> +};
> >>> +
> >>> +static struct wmi_driver lenovo_wmi_cd01_driver = {
> >>> + .driver = {
> >>> + .name = "lenovo_wmi_cd01",
> >>> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> >>> + },
> >>> + .id_table = lenovo_wmi_cd01_id_table,
> >>> + .probe = lenovo_wmi_cd01_probe,
> >>> + .remove = lenovo_wmi_cd01_remove,
> >>> + .no_singleton = true,
> >>> +};
> >>> +
> >>> +int lenovo_wmi_cd01_match(struct device *dev, void *data)
> >>> +{
> >>> + return dev->driver == &lenovo_wmi_cd01_driver.driver;
> >>> +}
> >>> +EXPORT_SYMBOL_GPL(lenovo_wmi_cd01_match);
> >> Please put this symbol into a namespace too.
> >>
> > Yes, I noticed the mistake right after I sent the patch.
> >
> >>> +
> >>> +module_wmi_driver(lenovo_wmi_cd01_driver);
> >>> +
> >>> +MODULE_DEVICE_TABLE(wmi, lenovo_wmi_cd01_id_table);
> >>> +MODULE_AUTHOR("Derek J. Clark <derekjohn.clark@gmail.com>");
> >>> +MODULE_DESCRIPTION("Lenovo Capability Data 01 WMI Driver");
> >>> +MODULE_LICENSE("GPL");
> >>> diff --git a/drivers/platform/x86/lenovo-wmi.h b/drivers/platform/x86/lenovo-wmi.h
> >>> index 113928b4fc0f..07fa67ed89d6 100644
> >>> --- a/drivers/platform/x86/lenovo-wmi.h
> >>> +++ b/drivers/platform/x86/lenovo-wmi.h
> >>> @@ -45,6 +45,22 @@ enum lenovo_wmi_action {
> >>> THERMAL_MODE_EVENT = 1,
> >>> };
> >>>
> >>> +/* capdata01 structs */
> >>> +struct lenovo_wmi_cd01 {
> >>> + struct capdata01 **capdata;
> >>> + struct wmi_device *wdev;
> >>> + int instance_count;
> >>> +};
> >>> +
> >>> +struct capdata01 {
> >>> + u32 id;
> >>> + u32 supported;
> >>> + u32 default_value;
> >>> + u32 step;
> >>> + u32 min_value;
> >>> + u32 max_value;
> >>> +};
> >> Please put those struct definitions into a separate header file.
> >>
> > Acked.
> >
> >> Thanks,
> >> Armin Wolf
> >>
> >>> +
> >>> /* wmidev_evaluate_method helper functions */
> >>> int lenovo_wmidev_evaluate_method_2(struct wmi_device *wdev, u8 instance,
> >>> u32 method_id, u32 arg0, u32 arg1,
> >>> @@ -52,6 +68,9 @@ int lenovo_wmidev_evaluate_method_2(struct wmi_device *wdev, u8 instance,
> >>> int lenovo_wmidev_evaluate_method_1(struct wmi_device *wdev, u8 instance,
> >>> u32 method_id, u32 arg0, u32 *retval);
> >>>
> >>> +/* lenovo_wmi_cd01_driver match function */
> >>> +int lenovo_wmi_cd01_match(struct device *dev, void *data);
> >>> +
> >>> /* lenovo_wmi_gz_driver notifier functions */
> >>> int lenovo_wmi_gz_notifier_call(struct notifier_block *nb, unsigned long action,
> >>> enum platform_profile_option *profile);