On Thu, Jan 9, 2025 at 2:35 PM Armin Wolf <W_Armin@xxxxxx> wrote:
>
> Am 02.01.25 um 01:47 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 Method"
> > 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.
> >
> > v2:
> > - Use devm_kzalloc 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@xxxxxxxxx>
> > ---
> > MAINTAINERS | 1 +
> > drivers/platform/x86/Kconfig | 11 ++
> > drivers/platform/x86/Makefile | 1 +
> > drivers/platform/x86/lenovo-wmi-capdata01.c | 131 ++++++++++++++++++++
> > drivers/platform/x86/lenovo-wmi.h | 20 +++
> > 5 files changed, 164 insertions(+)
> > create mode 100644 drivers/platform/x86/lenovo-wmi-capdata01.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 8f8a6aec6b92..c9374c395905 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -13038,6 +13038,7 @@ LENOVO WMI drivers
> > M: Derek J. Clark <derekjohn.clark@xxxxxxxxx>
> > L: platform-driver-x86@xxxxxxxxxxxxxxx
> > S: Maintained
> > +F: drivers/platform/x86/lenovo-wmi-capdata01.c
> > F: drivers/platform/x86/lenovo-wmi-gamezone.c
> > F: drivers/platform/x86/lenovo-wmi.h
> >
> > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> > index 9a6ac7fdec9f..a2c1ab47ad9e 100644
> > --- a/drivers/platform/x86/Kconfig
> > +++ b/drivers/platform/x86/Kconfig
> > @@ -470,6 +470,17 @@ 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 "Lenovo Legion WMI capability Data 01 Driver"
> > + depends on ACPI_WMI
> > + help
> > + Say Y here if you have a WMI aware Lenovo Legion device in the "Gaming Series"
> > + line of hardware. This interface is a dependency for exposing tunable power
> > + settings.
> > +
> > + To compile this driver as a module, choose M here: the module will
> > + be called lenovo_wmi_capdata01.
>
> Could it be that the resulting module will be called lenovo-wmi-capdata01? Also if its a mere
> dependency without any value when being used alone then it would make sense to hide it from
> users by removing the help texts:
>
> config LENOVO_WMI_DATA01
> tristate
> depends on ACPI_WMI
>
Makes sense, Will do
> > +
> > config IDEAPAD_LAPTOP
> > tristate "Lenovo IdeaPad Laptop Extras"
> > depends on ACPI
> > diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> > index 7cb29a480ed2..6c96cc3f3855 100644
> > --- a/drivers/platform/x86/Makefile
> > +++ b/drivers/platform/x86/Makefile
> > @@ -69,6 +69,7 @@ obj-$(CONFIG_YOGABOOK) += lenovo-yogabook.o
> > obj-$(CONFIG_YT2_1380) += lenovo-yoga-tab2-pro-1380-fastcharger.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..b10a6e4b320f
> > --- /dev/null
> > +++ b/drivers/platform/x86/lenovo-wmi-capdata01.c
> > @@ -0,0 +1,131 @@
> > +// 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 Method" 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@xxxxxxxxx>
> > + */
> > +
> > +#include <linux/list.h>
> > +#include "lenovo-wmi.h"
> > +
> > +#define LENOVO_CAPABILITY_DATA_01_GUID "7A8F5407-CB67-4D6E-B547-39B3BE018154"
> > +
> > +static DEFINE_MUTEX(cd01_call_mutex);
>
> Does the WMI interface really rely on such mutual exclusion of callers? If no then
> please remove this mutex.
>
As with the other drivers, will remove.
> > +static DEFINE_MUTEX(cd01_list_mutex);
> > +static LIST_HEAD(cd01_wmi_list);
> > +
> > +static const struct wmi_device_id lenovo_wmi_capdata01_id_table[] = {
> > + { LENOVO_CAPABILITY_DATA_01_GUID, NULL },
> > + {}
> > +};
> > +
> > +struct lenovo_wmi_cd01_priv {
> > + struct wmi_device *wdev;
> > + struct list_head list;
> > +};
> > +
> > +static inline struct lenovo_wmi_cd01_priv *get_first_wmi_priv(void)
> > +{
> > + guard(mutex)(&cd01_list_mutex);
> > + return list_first_entry_or_null(&cd01_wmi_list,
> > + struct lenovo_wmi_cd01_priv, list);
>
> Two things:
>
> 1. This will cause issues should a WMI device in this list be removed while a
> consumer is using it. In this case you will need extend the scope of the list mutex.
>
> 2. Do multiple capdata01 WMI devices exist in any systems? If no then please consider
> using the component framework (https://docs.kernel.org/driver-api/component.html) which
> will simplify the interop between the consumer driver of capdata01 and this driver.
>
I looked into this and struggled with it for a while, do you have any
good examples I can reference?
Will this allow me to pass struct lenovo_wmi_cd01_priv *priv to this
function from the other mode driver? If so, should I avoid calling it
priv since it will be accessible outside the driver?
> > +}
> > +
> > +int lenovo_wmi_capdata01_get(struct lenovo_wmi_attr_id attr_id,
> > + struct capability_data_01 *cap_data)
> > +{
> > + u32 attribute_id = *(int *)&attr_id;
>
> This will cause alignment issues, please use FIELD_GET()/FIELD_PREP() to construct a u32 to
> pass to this function.
>
Can do.
> > + struct lenovo_wmi_cd01_priv *priv;
> > + union acpi_object *ret_obj;
> > + int instance_idx;
> > + int count;
> > +
> > + priv = get_first_wmi_priv();
> > + if (!priv)
> > + return -ENODEV;
> > +
> > + guard(mutex)(&cd01_call_mutex);
> > + count = wmidev_instance_count(priv->wdev);
> > + pr_info("Got instance count: %u\n", count);
> > +
> > + for (instance_idx = 0; instance_idx < count; instance_idx++) {
> > + ret_obj = wmidev_block_query(priv->wdev, instance_idx);
> > + if (!ret_obj) {
> > + pr_err("WMI Data block query failed.\n");
> > + continue;
> > + }
> > +
> > + if (ret_obj->type != ACPI_TYPE_BUFFER) {
> > + pr_err("WMI Data block query returned wrong type.\n");
> > + kfree(ret_obj);
> > + continue;
> > + }
> > +
> > + if (ret_obj->buffer.length != sizeof(*cap_data)) {
> > + pr_err("WMI Data block query returned wrong buffer length: %u vice expected %lu.\n",
> > + ret_obj->buffer.length, sizeof(*cap_data));
> > + kfree(ret_obj);
> > + continue;
> > + }
> > +
> > + memcpy(cap_data, ret_obj->buffer.pointer,
> > + ret_obj->buffer.length);
> > + kfree(ret_obj);
> > +
> > + if (cap_data->id != attribute_id)
> > + continue;
> > + break;
> > + }
>
> Maybe it would make sense to read this data during device initialization and store it
> inside an array? This way looking up capability data would be _much_ faster especially
> since WMI calls are usually quite slow.
>
I was looking into this as I agree that would be preferable but wasn't
able to get a working version. Since I don't know the array length at
compile time I tried using krealloc_array after getting
wmidev_instance_count to resize a capdata array stored in priv, but
that would result in the driver crashing for some reason. I'll take
another shot at it.
> Also this function is way to noisy when it comes to error messages. Please leave this
> to the caller of this function.
Can do. If I don't get a ret_obj should I quit the loop here?
> > +
> > + if (cap_data->id != attribute_id) {
> > + pr_err("Unable to find capability data for attribute_id %x\n",
> > + attribute_id);
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_NS_GPL(lenovo_wmi_capdata01_get, "CAPDATA_WMI");
> > +
> > +static int lenovo_wmi_capdata01_probe(struct wmi_device *wdev,
> > + const void *context)
> > +
> > +{
> > + struct lenovo_wmi_cd01_priv *priv;
> > +
> > + priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> > + if (!priv)
> > + return -ENOMEM;
> > +
> > + priv->wdev = wdev;
> > +
> > + guard(mutex)(&cd01_list_mutex);
> > + list_add_tail(&priv->list, &cd01_wmi_list);
> > +
> > + return 0;
> > +}
> > +
> > +static void lenovo_wmi_capdata01_remove(struct wmi_device *wdev)
> > +{
> > + struct lenovo_wmi_cd01_priv *priv = dev_get_drvdata(&wdev->dev);
> > +
> > + guard(mutex)(&cd01_list_mutex);
> > + list_del(&priv->list);
> > +}
> > +
> > +static struct wmi_driver lenovo_wmi_capdata01_driver = {
> > + .driver = { .name = "lenovo_wmi_capdata01" },
>
> Please set ".probe_type = PROBE_PREFER_ASYNCHRONOUS".
>
Ack
> > + .id_table = lenovo_wmi_capdata01_id_table,
> > + .probe = lenovo_wmi_capdata01_probe,
> > + .remove = lenovo_wmi_capdata01_remove,
>
> Please set ".no_singleton = true".
>
Ack
Thanks,
Derek
> Thanks,
> Armin Wolf
>
> > +};
> > +
> > +module_wmi_driver(lenovo_wmi_capdata01_driver);
> > +
> > +MODULE_DEVICE_TABLE(wmi, lenovo_wmi_capdata01_id_table);
> > +MODULE_AUTHOR("Derek J. Clark <derekjohn.clark@xxxxxxxxx>");
> > +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 8a302c6c47cb..53cea84a956b 100644
> > --- a/drivers/platform/x86/lenovo-wmi.h
> > +++ b/drivers/platform/x86/lenovo-wmi.h
> > @@ -36,6 +36,22 @@ struct wmi_method_args {
> > u32 arg1;
> > };
> >
> > +struct lenovo_wmi_attr_id {
> > + u32 mode_id : 16; /* Fan profile */
> > + u32 feature_id : 8; /* Attribute (SPL/SPPT/...) */
> > + u32 device_id : 8; /* CPU/GPU/... */
> > +} __packed;
> > +
> > +/* Data struct for LENOVO_CAPABILITY_DATA_01 */
> > +struct capability_data_01 {
> > + u32 id;
> > + u32 supported;
> > + u32 default_value;
> > + u32 step;
> > + u32 min_value;
> > + u32 max_value;
> > +};
> > +
> > /* General Use functions */
> > static int lenovo_wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
> > u32 method_id, struct acpi_buffer *in,
> > @@ -102,4 +118,8 @@ int lenovo_wmidev_evaluate_method_1(struct wmi_device *wdev, u8 instance,
> > 0, retval);
> > }
> >
> > +/* LENOVO_CAPABILITY_DATA_01 exported functions */
> > +int lenovo_wmi_capdata01_get(struct lenovo_wmi_attr_id attr_id,
> > + struct capability_data_01 *cap_data);
> > +
> > #endif /* !_LENOVO_WMI_H_ */
