Message-ID: <CAFqHKTnaJC+gcMO8cwfM1S48hv4AFehcCDCKpLitq2zvhBWJrQ@mail.gmail.com>
Date: Sat, 11 Jan 2025 19:25:47 -0800
From: Derek John Clark <derekjohn.clark@...il.com>
To: Armin Wolf <W_Armin@....de>
Cc: Hans de Goede <hdegoede@...hat.com>, Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>, 
	Jonathan Corbet <corbet@....net>, Mario Limonciello <superm1@...nel.org>, Luke Jones <luke@...nes.dev>, 
	Xino Ni <nijs1@...ovo.com>, Zhixin Zhang <zhangzx36@...ovo.com>, Mia Shao <shaohz1@...ovo.com>, 
	Mark Pearson <mpearson-lenovo@...ebb.ca>, 
	"Pierre-Loup A . Griffais" <pgriffais@...vesoftware.com>, "Cody T . -H . Chiu" <codyit@...il.com>, 
	John Martens <johnfanv2@...il.com>, platform-driver-x86@...r.kernel.org, 
	linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/4] platform/x86: Add Lenovo GameZone WMI Driver

On Fri, Jan 10, 2025 at 1:33 PM Derek John Clark
<derekjohn.clark@...il.com> wrote:
>
> On Thu, Jan 9, 2025 at 2:12 PM Armin Wolf <W_Armin@....de> wrote:
> >
> > Am 02.01.25 um 01:47 schrieb Derek J. Clark:
> >
> > > Adds lenovo-wmi-gamezone.c which provides a driver for the Lenovo
> > > GameZone WMI interface that comes on Lenovo "Gaming Series" hardware.
> > > Provides ACPI platform profiles over WMI.
> > >
> > > 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 gamezone_wmi to lenovo_wmi_gz_priv and gz_wmi to priv.
> > > - Remove GZ_WMI symbol exporting.
> > >
> > > Signed-off-by: Derek J. Clark <derekjohn.clark@...il.com>
> > > ---
> > >   MAINTAINERS                                |   7 +
> > >   drivers/platform/x86/Kconfig               |  11 ++
> > >   drivers/platform/x86/Makefile              |   1 +
> > >   drivers/platform/x86/lenovo-wmi-gamezone.c | 203 +++++++++++++++++++++
> > >   drivers/platform/x86/lenovo-wmi.h          | 105 +++++++++++
> > >   5 files changed, 327 insertions(+)
> > >   create mode 100644 drivers/platform/x86/lenovo-wmi-gamezone.c
> > >   create mode 100644 drivers/platform/x86/lenovo-wmi.h
> > >
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index baf0eeb9a355..8f8a6aec6b92 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -13034,6 +13034,13 @@ S:   Maintained
> > >   W:  http://legousb.sourceforge.net/
> > >   F:  drivers/usb/misc/legousbtower.c
> > >
> > > +LENOVO WMI drivers
> > > +M:   Derek J. Clark <derekjohn.clark@...il.com>
> > > +L:   platform-driver-x86@...r.kernel.org
> > > +S:   Maintained
> > > +F:   drivers/platform/x86/lenovo-wmi-gamezone.c
> > > +F:   drivers/platform/x86/lenovo-wmi.h
> > > +
> > >   LETSKETCH HID TABLET DRIVER
> > >   M:  Hans de Goede <hdegoede@...hat.com>
> > >   L:  linux-input@...r.kernel.org
> > > diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> > > index 0258dd879d64..9a6ac7fdec9f 100644
> > > --- a/drivers/platform/x86/Kconfig
> > > +++ b/drivers/platform/x86/Kconfig
> > > @@ -459,6 +459,17 @@ config IBM_RTL
> > >        state = 0 (BIOS SMIs on)
> > >        state = 1 (BIOS SMIs off)
> > >
> > > +config LENOVO_WMI_GAMEZONE
> > > +     tristate "Lenovo GameZone WMI Driver"
> > > +     depends on ACPI_WMI
> > > +     select ACPI_PLATFORM_PROFILE
> > > +     help
> > > +       Say Y here if you have a WMI aware Lenovo Legion device and would like to use the
> > > +       platform-profile firmware interface.
> > > +
> > > +       To compile this driver as a module, choose M here: the module will
> > > +       be called lenovo_wmi_gamezone.
> >
> > Could it be that the resulting kernel module is actually named lenovo-wmi-gamezone?.
> > If yes then please adjust the config description.
> >
>
> the .o/.ko are named as you described with -, but lsmod lists them
> with _ which is how most would interact with the driver if manually
> loading or blocking it. I'll put whichever you think is most
> appropriate.
>
> > > +
> > >   config IDEAPAD_LAPTOP
> > >       tristate "Lenovo IdeaPad Laptop Extras"
> > >       depends on ACPI
> > > diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> > > index e1b142947067..7cb29a480ed2 100644
> > > --- a/drivers/platform/x86/Makefile
> > > +++ b/drivers/platform/x86/Makefile
> > > @@ -68,6 +68,7 @@ obj-$(CONFIG_THINKPAD_LMI)  += think-lmi.o
> > >   obj-$(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
> > >
> > >   # Intel
> > >   obj-y                               += intel/
> > > diff --git a/drivers/platform/x86/lenovo-wmi-gamezone.c b/drivers/platform/x86/lenovo-wmi-gamezone.c
> > > new file mode 100644
> > > index 000000000000..da5e2bc41f39
> > > --- /dev/null
> > > +++ b/drivers/platform/x86/lenovo-wmi-gamezone.c
> > > @@ -0,0 +1,203 @@
> > > +// SPDX-License-Identifier: GPL-2.0-or-later
> > > +/*
> > > + * Lenovo GameZone WMI interface driver. The GameZone WMI interface provides
> > > + * platform profile and fan curve settings for devices that fall under the
> > > + * "Gaming Series" of Lenovo Legion devices.
> > > + *
> > > + * Copyright(C) 2024 Derek J. Clark <derekjohn.clark@...il.com>
> > > + */
> > > +
> > > +#include <linux/platform_profile.h>
> > > +#include "lenovo-wmi.h"
> >
> > Please add the necessary includes here and do not rely on the header file to pull them in.
> >
>
> Ack
>
> > > +
> > > +#define LENOVO_GAMEZONE_GUID "887B54E3-DDDC-4B2C-8B88-68A26A8835D0"
> > > +
> > > +/* Method IDs */
> > > +#define WMI_METHOD_ID_SMARTFAN_SUPP 43 /* IsSupportSmartFan */
> > > +#define WMI_METHOD_ID_SMARTFAN_SET 44 /* SetSmartFanMode */
> > > +#define WMI_METHOD_ID_SMARTFAN_GET 45 /* GetSmartFanMode */
> > > +
> > > +static DEFINE_MUTEX(call_mutex);
> > > +
> > > +static const struct wmi_device_id lenovo_wmi_gamezone_id_table[] = {
> > > +     { LENOVO_GAMEZONE_GUID, NULL }, /* LENOVO_GAMEZONE_DATA */
> > > +     {}
> > > +};
> >
> > Please move those device IDs closer to the driver struct which uses them.
> >
>
> Ack
>
> > > +
> > > +struct lenovo_wmi_gz_priv {
> > > +     struct wmi_device *wdev;
> > > +     enum platform_profile_option current_profile;
> > > +     struct platform_profile_handler pprof;
> > > +     bool platform_profile_support;
> > > +};
> > > +
> > > +/* Platform Profile Methods */
> > > +static int lenovo_wmi_gamezone_platform_profile_supported(
> > > +     struct platform_profile_handler *pprof, int *supported)
> >
> > Please use ./scripts/checkpatch --strict to catch any coding style violations like this one.
> >
>
> Ack. Sorry about that.
>
> > > +{
> > > +     struct lenovo_wmi_gz_priv *priv;
> > > +
> > > +     priv = container_of(pprof, struct lenovo_wmi_gz_priv, pprof);
> >
> > Is there a reason why you are not passing priv as an argument? If no then please pass priv
> > as an argument so you can avoid having to use container_of().
> >
> > > +
> > > +     guard(mutex)(&call_mutex);
> >
> > Is there a technical reason why you have to use a mutex for WMI method access? If no then please remove
> > this mutex.
> >
>
> We weren't sure and figured you would know best practice. I'll remove them.
>
> > > +     return lenovo_wmidev_evaluate_method_1(
> > > +             priv->wdev, 0x0, WMI_METHOD_ID_SMARTFAN_SUPP, 0, supported);
> > > +}
> > > +
> > > +static int
> > > +lenovo_wmi_gamezone_profile_get(struct platform_profile_handler *pprof,
> > > +                             enum platform_profile_option *profile)
> > > +{
> > > +     struct lenovo_wmi_gz_priv *priv;
> > > +     int sel_prof;
> > > +     int err;
> > > +
> > > +     priv = container_of(pprof, struct lenovo_wmi_gz_priv, pprof);
> > > +
> > > +     guard(mutex)(&call_mutex);
> > > +     err = lenovo_wmidev_evaluate_method_1(
> > > +             priv->wdev, 0x0, WMI_METHOD_ID_SMARTFAN_GET, 0, &sel_prof);
> > > +     if (err) {
> > > +             pr_err("Error getting fan profile from WMI interface: %d\n",
> > > +                    err);
> >
> > Please just return here without printing anything, userspace does not benefit from such
> > an error message which only states the obvious.
> >
>
> Ack all debug return messages.
>
> > > +             return err;
> > > +     }
> > > +
> > > +     switch (sel_prof) {
> > > +     case SMARTFAN_MODE_QUIET:
> > > +             *profile = PLATFORM_PROFILE_QUIET;
> > > +             break;
> > > +     case SMARTFAN_MODE_BALANCED:
> > > +             *profile = PLATFORM_PROFILE_BALANCED;
> > > +             break;
> > > +     case SMARTFAN_MODE_PERFORMANCE:
> > > +             *profile = PLATFORM_PROFILE_PERFORMANCE;
> > > +             break;
> > > +     case SMARTFAN_MODE_CUSTOM:
> > > +             *profile = PLATFORM_PROFILE_CUSTOM;
> > > +             break;
> > > +     default:
> > > +             return -EINVAL;
> > > +     }
> > > +     priv->current_profile = *profile;
> >
> > Please remove this unused variable from priv.
> >
>
> Ack
>
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int
> > > +lenovo_wmi_gamezone_profile_set(struct platform_profile_handler *pprof,
> > > +                             enum platform_profile_option profile)
> > > +{
> > > +     struct lenovo_wmi_gz_priv *priv;
> > > +     int sel_prof;
> > > +     int err;
> > > +
> > > +     switch (profile) {
> > > +     case PLATFORM_PROFILE_QUIET:
> > > +             sel_prof = SMARTFAN_MODE_QUIET;
> > > +             break;
> > > +     case PLATFORM_PROFILE_BALANCED:
> > > +             sel_prof = SMARTFAN_MODE_BALANCED;
> > > +             break;
> > > +     case PLATFORM_PROFILE_PERFORMANCE:
> > > +             sel_prof = SMARTFAN_MODE_PERFORMANCE;
> > > +             break;
> > > +     case PLATFORM_PROFILE_CUSTOM:
> > > +             sel_prof = SMARTFAN_MODE_CUSTOM;
> > > +             break;
> > > +     default:
> > > +             return -EOPNOTSUPP;
> > > +     }
> > > +
> > > +     priv = container_of(pprof, struct lenovo_wmi_gz_priv, pprof);
> >
> > Please assign priv during declaration.
> >
>
> Ack
>
> > > +
> > > +     guard(mutex)(&call_mutex);
> > > +     err = lenovo_wmidev_evaluate_method_1(
> > > +             priv->wdev, 0x0, WMI_METHOD_ID_SMARTFAN_SET, sel_prof, NULL);
> > > +     if (err) {
> > > +             pr_err("Error setting fan profile on WMI interface: %u\n", err);
> >
> > Again, this error message only states the obvious, please remove it.
> >
> > > +             return err;
> > > +     }
> > > +
> > > +     priv->current_profile = profile;
> > > +     return 0;
> > > +}
> > > +
> > > +/* Driver Setup */
> > > +static int platform_profile_setup(struct lenovo_wmi_gz_priv *priv)
> > > +{
> > > +     int supported;
> > > +     int err;
> > > +
> > > +     err = lenovo_wmi_gamezone_platform_profile_supported(&priv->pprof,
> > > +                                                          &supported);
> > > +     if (err) {
> > > +             pr_err("Error checking platform profile support: %d\n", err);
> > > +             return err;
> >
> > Please use dev_err() here.
>
> Ack
>
> > > +     }
> > > +
> > > +     priv->platform_profile_support = supported;
> >
> > The value of platform_profile_support is not used anywhere, please remove it.
> >
> > > +
> > > +     if (!supported)
> > > +             return -EOPNOTSUPP;
> >
> > IMHO returning -ENODEV would make more sense here.
> >
>
> Ack
>
> > > +
> > > +     priv->pprof.name = "lenovo-wmi-gamezone";
> > > +     priv->pprof.profile_get = lenovo_wmi_gamezone_profile_get;
> > > +     priv->pprof.profile_set = lenovo_wmi_gamezone_profile_set;
> > > +
> > > +     set_bit(PLATFORM_PROFILE_QUIET, priv->pprof.choices);
> > > +     set_bit(PLATFORM_PROFILE_BALANCED, priv->pprof.choices);
> > > +     set_bit(PLATFORM_PROFILE_PERFORMANCE, priv->pprof.choices);
> > > +     set_bit(PLATFORM_PROFILE_CUSTOM, priv->pprof.choices);
> > > +
> > > +     err = lenovo_wmi_gamezone_profile_get(&priv->pprof,
> > > +                                           &priv->current_profile);
> > > +     if (err) {
> > > +             pr_err("Error getting current platform profile: %d\n", err);
> > > +             return err;
> > > +     }
> >
> > Is there a technical reason for reading the current platform profile during device
> > initialization(? If no then please remove this call.
> >
>
> There isn't, just a misconception on my part. WIll remove.
>
> > > +
> > > +     guard(mutex)(&call_mutex);
> > > +     err = platform_profile_register(&priv->pprof);
> >
> > Using devm_platform_profile_register() would make sense here. This function was added very recently
> > so you have to base your patch series onto the for-next branch.
> >
>
> Ack
>
> > > +     if (err) {
> > > +             pr_err("Error registering platform profile: %d\n", err);
> > > +             return err;
> > > +     }
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int lenovo_wmi_gamezone_probe(struct wmi_device *wdev,
> > > +                                  const void *context)
> > > +{
> > > +     struct lenovo_wmi_gz_priv *priv;
> > > +
> > > +     priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> > > +     if (!priv)
> > > +             return -ENOMEM;
> > > +
> > > +     priv->wdev = wdev;
> >
> > Since you are using dev_get_drvdata(), you also need to use dev_set_drvdata() here, otherwise
> > dev_get_drvdata() will return no valid value.
> >
>
> Ack
>
> > > +     return platform_profile_setup(priv);
> > > +}
> > > +
> > > +static void lenovo_wmi_gamezone_remove(struct wmi_device *wdev)
> > > +{
> > > +     struct lenovo_wmi_gz_priv *priv = dev_get_drvdata(&wdev->dev);
> > > +
> > > +     guard(mutex)(&call_mutex);
> > > +     platform_profile_remove(&priv->pprof);
> > > +}
> > > +
> > > +static struct wmi_driver lenovo_wmi_gamezone_driver = {
> > > +     .driver = { .name = "lenovo_wmi_gamezone" },
> >
> > Please set ".probe_type = PROBE_PREFER_ASYNCHRONOUS" here.
> >
>
> Ack
>
> > Also does the selected fan profile remain the same after suspending or hibernating?
> > If no then please add the necessary PM callbacks to save/restore the fan profile
> > before suspend/after resume if necessary.
> >
>
> It remains the same after suspend, hibernate, reboot, and shutdown.
>
> > > +     .id_table = lenovo_wmi_gamezone_id_table,
> > > +     .probe = lenovo_wmi_gamezone_probe,
> > > +     .remove = lenovo_wmi_gamezone_remove,
> >
> > Please set ".no_singleton = true" here.
> >
>
> Ack
>
> > > +};
> > > +
> > > +module_wmi_driver(lenovo_wmi_gamezone_driver);
> > > +
> > > +MODULE_DEVICE_TABLE(wmi, lenovo_wmi_gamezone_id_table);
> > > +MODULE_AUTHOR("Derek J. Clark <derekjohn.clark@...il.com>");
> > > +MODULE_DESCRIPTION("Lenovo GameZone WMI Driver");
> > > +MODULE_LICENSE("GPL");
> > > diff --git a/drivers/platform/x86/lenovo-wmi.h b/drivers/platform/x86/lenovo-wmi.h
> > > new file mode 100644
> > > index 000000000000..8a302c6c47cb
> > > --- /dev/null
> > > +++ b/drivers/platform/x86/lenovo-wmi.h
> > > @@ -0,0 +1,105 @@
> > > +/* SPDX-License-Identifier: GPL-2.0-or-later
> > > + *
> > > + * Lenovo Legion WMI interface driver. The Lenovo Legion WMI interface is
> > > + * broken up into multiple GUID interfaces that require cross-references
> > > + * between GUID's for some functionality. The "Custom Mode" interface is a
> > > + * legacy interface for managing and displaying CPU & GPU power and hwmon
> > > + * settings and readings. The "Other Mode" interface is a modern interface
> > > + * that replaces or extends the "Custom Mode" interface methods. The
> > > + * "GameZone" interface adds advanced features such as fan profiles and
> > > + * overclocking. The "Lighting" interface adds control of various status
> > > + * lights related to different hardware components. "Other Method" uses
> > > + * the data structs LENOVO_CAPABILITY_DATA_00, LENOVO_CAPABILITY_DATA_01
> > > + * and LENOVO_CAPABILITY_DATA_02 structs for capability information.
> > > + *
> > > + * Copyright(C) 2024 Derek J. Clark <derekjohn.clark@...il.com>
> > > + *
> > > + */
> > > +
> > > +#define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__
> > > +
> > > +#ifndef _LENOVO_WMI_H_
> > > +#define _LENOVO_WMI_H_
> > > +
> > > +#include <linux/mutex.h>
> > > +#include <linux/types.h>
> > > +#include <linux/wmi.h>
> > > +
> > > +/* Platform Profile Modes */
> > > +#define SMARTFAN_MODE_QUIET 0x01
> > > +#define SMARTFAN_MODE_BALANCED 0x02
> > > +#define SMARTFAN_MODE_PERFORMANCE 0x03
> > > +#define SMARTFAN_MODE_CUSTOM 0xFF
> > > +
> > > +struct wmi_method_args {
> > > +     u32 arg0;
> > > +     u32 arg1;
> > > +};
> > > +
> > > +/* General Use functions */
> > > +static int lenovo_wmidev_evaluate_method(struct wmi_device *wdev, u8 instance,
> > > +                                      u32 method_id, struct acpi_buffer *in,
> > > +                                      struct acpi_buffer *out)
> > > +{
> > > +     acpi_status status;
> > > +
> > > +     status = wmidev_evaluate_method(wdev, instance, method_id, in, out);
> > > +
> > > +     if (ACPI_FAILURE(status))
> > > +             return -EIO;
> > > +
> > > +     return 0;
> > > +};
> > > +
> > > +int lenovo_wmidev_evaluate_method_2(struct wmi_device *wdev, u8 instance,
> > > +                                 u32 method_id, u32 arg0, u32 arg1,
> > > +                                 u32 *retval);
> > > +
> > > +int lenovo_wmidev_evaluate_method_2(struct wmi_device *wdev, u8 instance,
> > > +                                 u32 method_id, u32 arg0, u32 arg1,
> > > +                                 u32 *retval)
> > > +{
> > > +     struct wmi_method_args args = { arg0, arg1 };
> > > +     struct acpi_buffer input = { (acpi_size)sizeof(args), &args };
> > > +     struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
> > > +     union acpi_object *ret_obj = NULL;
> > > +     int err;
> >
> > Please order the variable declarations in reverse XMAS tree order.
> >
>
> Ack
>
Armin,

After looking at this again, args is used by output so it needs to be
before it. I'll swap input and output unless you have another
suggestion.

Cheers,
Derek

> > > +
> > > +     err = lenovo_wmidev_evaluate_method(wdev, instance, method_id, &input,
> > > +                                         &output);
> > > +
> > > +     if (err) {
> > > +             pr_err("Attempt to get method value failed.\n");
> >
> > Please remove any error messages in this part of the code, printing error messages should
> > ideally happen at the higher layers of the driver if necessary.
> >
> > > +             return err;
> > > +     }
> > > +
> > > +     if (retval) {
> > > +             ret_obj = (union acpi_object *)output.pointer;
> > > +             if (!ret_obj) {
> > > +                     pr_err("Failed to get valid ACPI object from WMI interface\n");
> > > +                     return -EIO;
> >
> > -ENODATA.
> >
>
> Ack
>
> > > +             }
> > > +             if (ret_obj->type != ACPI_TYPE_INTEGER) {
> > > +                     pr_err("WMI query returnd ACPI object with wrong type.\n");
> > > +                     kfree(ret_obj);
> > > +                     return -EIO;
> >
> > -ENXIO.
> >
>
> Ack
>
> > > +             }
> > > +             *retval = (u32)ret_obj->integer.value;
> > > +     }
> > > +
> > > +     kfree(ret_obj);
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +int lenovo_wmidev_evaluate_method_1(struct wmi_device *wdev, u8 instance,
> > > +                                 u32 method_id, u32 arg0, u32 *retval);
> > > +
> > > +int lenovo_wmidev_evaluate_method_1(struct wmi_device *wdev, u8 instance,
> > > +                                 u32 method_id, u32 arg0, u32 *retval)
> > > +{
> > > +     return lenovo_wmidev_evaluate_method_2(wdev, instance, method_id, arg0,
> > > +                                            0, retval);
> > > +}
> > > +
> > > +#endif /* !_LENOVO_WMI_H_ */
>
> Thanks Armin,
> Derek

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