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

Armin Wolf
2025-03-11T20:33:49Z

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

>
>>> + 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);