* Re: [RFC PATCH 3/3] platform/x86: lenovo: Add Legion Go Fan Method curve driver
2026-08-21 21:47 ` [RFC PATCH 3/3] platform/x86: lenovo: Add Legion Go Fan Method curve driver Aditya Dash
@ 2026-08-22 18:47 ` Antheas Kapenekakis
2026-08-23 21:09 ` Rong Zhang
` (2 subsequent siblings)
3 siblings, 0 replies; 18+ messages in thread
From: Antheas Kapenekakis @ 2026-08-22 18:47 UTC (permalink / raw)
To: Aditya Dash
Cc: Derek J. Clark, Ilpo Järvinen, Armin Wolf, Hans de Goede,
Mark Pearson, Guenter Roeck, Jonathan Corbet, Shuah Khan,
linux-doc, linux-hwmon, linux-kernel, platform-driver-x86
On Fri, 21 Aug 2026 at 23:47, Aditya Dash <mradityadash@gmail.com> wrote:
>
> Legion Go firmware keeps its custom fan curve in a separate Fan Method WMI
> interface. Method 5 returns ten control values and ten temperatures, while
> Method 6 replaces the complete table.
10 is a value that is returned to you by the WMI array (it is the
first value), you actually do not know if the driver supports 10
points. You should validate this somehow and perhaps exit. An init
check during probe calling the getter and seeing if it displays an
error because of point mismatch to bail the driver should suffice, and
should allow you to keep complex arbitrary point logic out of the
driver.
> The GUID also appears on Lenovo systems with a different table layout.
> Limit the driver to Legion Go 8APU1, Legion Go 8ASP2, Legion Go 8AHP2,
> Legion Go S 8ARP1, and Legion Go S 8APU1 products. These products use the
> same ten-point layout and Method 6 request.
>
> The curve applies to the same fan as the existing Other Mode attributes.
> Add a separate WMI driver and attach the ten automatic-point pairs to the
> HWMON device that Other Mode already provides. Match devices from the same
> WMI provider. Other Mode continues to work without Fan Method. Probe does
> not invoke either method.
>
> Validate both counts, every control value, and the complete temperature
> table before using a Method 5 reply. A point write holds the mutex while
> it reads the current table, changes one control value, and submits the
> complete Method 6 request. The other values remain unchanged.
>
> The HWMON mapping is not clear. On the tested Legion Go 8APU1, the fan
> responds to values from 0 through 115. This is Lenovo's 0 through 115
> percent range. Lenovo software shows 0 through 100 percent to the user,
> and 115 reaches the RPM observed in Full Speed mode. Firmware accepts
> values through 255, but values above 115 caused no observed RPM increase.
You should tighten this description and preferably rewrite it by hand.
> This RFC exposes the firmware values unchanged. The fixed temperatures are
> read-only.
Drop this sentence. If you need to describe the RFC, do it in the cover letter.
> Assisted-by: Pi:gpt-5.6-sol
> Signed-off-by: Aditya Dash <mradityadash@gmail.com>
> ---
> .../wmi/devices/lenovo-wmi-fan-method.rst | 34 ++
> .../wmi/devices/lenovo-wmi-other.rst | 3 +
> MAINTAINERS | 1 +
> drivers/platform/x86/lenovo/Kconfig | 11 +
> drivers/platform/x86/lenovo/Makefile | 1 +
> drivers/platform/x86/lenovo/wmi-fan-method.c | 380 ++++++++++++++++++
> drivers/platform/x86/lenovo/wmi-other.c | 97 ++++-
> 7 files changed, 520 insertions(+), 7 deletions(-)
> create mode 100644 Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> create mode 100644 drivers/platform/x86/lenovo/wmi-fan-method.c
>
> diff --git a/Documentation/wmi/devices/lenovo-wmi-fan-method.rst b/Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> new file mode 100644
> index 000000000000..67c9a92ed992
> --- /dev/null
> +++ b/Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> @@ -0,0 +1,34 @@
> +.. SPDX-License-Identifier: GPL-2.0-or-later
> +
> +==================================
> +Lenovo Fan Method WMI Driver
> +==================================
> +
> +WMI GUID ``92549549-4BDE-4F06-AC04-CE8BF898DBAA``
> +
> +The Lenovo Fan Method interface provides a ten-point firmware fan table on
> +Legion Go 8APU1, Legion Go 8ASP2, Legion Go 8AHP2, Legion Go S 8ARP1, and
> +Legion Go S 8APU1 products.
> +
> +The driver adds ``pwm1_auto_point1_*`` through
> +``pwm1_auto_point10_*`` to the HWMON device that the Lenovo Other Mode driver
> +owns. The temperature attributes are fixed and read-only. They contain points
> +from 10 through 100 degrees Celsius in 10-degree steps.
> +
> +Each ``pwm1_auto_point*_pwm`` attribute is read-write and passes a firmware
> +control value from 0 through 255 without scaling. On the tested Legion Go
> +8APU1, the hardware responds from 0 through 115, corresponding to Lenovo's
> +0 through 115 percent range. Lenovo software shows 0 through 100 percent to
> +the user, and 115 percent reaches the RPM observed in Full Speed mode. The
> +firmware accepts values through 255, but values above 115 caused no observed
> +RPM increase.
> +
> +A control-value read validates both ten-entry tables before returning data. A
> +point write reads the current table, changes one control value, and submits the
> +complete request. It preserves the other nine control values and all returned
> +temperatures.
> +
> +The Fan Method and Other Mode drivers use separate modules and WMI devices.
> +The component framework associates devices that belong to the same WMI
> +provider. Fan Method curve attributes are absent when either interface is not
> +available.
>
> diff --git a/Documentation/wmi/devices/lenovo-wmi-other.rst b/Documentation/wmi/devices/lenovo-wmi-other.rst
> index c93e9e6f3fd0..34352dbd6fb9 100644
> --- a/Documentation/wmi/devices/lenovo-wmi-other.rst
> +++ b/Documentation/wmi/devices/lenovo-wmi-other.rst
> @@ -60,6 +60,9 @@ Some Legion Go firmware does not advertise fan 1 RPM through Capability
> Data. In that case, the driver reads Other Mode feature ``0x04030001`` for
> ``fan1_input``. Value ``0xffffffff`` means that RPM is unavailable.
>
> +When the separate Lenovo Fan Method driver binds to the same WMI provider, it
> +adds ten automatic fan-curve points to this HWMON device.
> +
> LENOVO_CAPABILITY_DATA_01
> -------------------------
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3820b286f09f..8612c2323540 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14689,6 +14689,7 @@ M: Mark Pearson <mpearson-lenovo@squebb.ca>
> M: Derek J. Clark <derekjohn.clark@gmail.com>
> L: platform-driver-x86@vger.kernel.org
> S: Maintained
> +F: Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> F: Documentation/wmi/devices/lenovo-wmi-gamezone.rst
> F: Documentation/wmi/devices/lenovo-wmi-other.rst
> F: drivers/platform/x86/lenovo/*
> diff --git a/drivers/platform/x86/lenovo/Kconfig b/drivers/platform/x86/lenovo/Kconfig
> index 4443f40ef8aa..e69942ce3093 100644
> --- a/drivers/platform/x86/lenovo/Kconfig
> +++ b/drivers/platform/x86/lenovo/Kconfig
> @@ -276,3 +276,14 @@ config LENOVO_WMI_TUNING
>
> To compile this driver as a module, choose M here: the module will
> be called lenovo-wmi-other.
> +
> +config LENOVO_WMI_FAN_METHOD
> + tristate "Lenovo Fan Method WMI Driver"
> + depends on DMI
> + depends on LENOVO_WMI_TUNING
> + help
> + Say Y here to add the firmware fan table on supported Lenovo
> + Legion Go products to the Lenovo Other Mode HWMON device.
> +
> + To compile this driver as a module, choose M here: the module will
> + be called lenovo-wmi-fan-method.
> diff --git a/drivers/platform/x86/lenovo/Makefile b/drivers/platform/x86/lenovo/Makefile
> index 91a9370f11b3..171a19e01479 100644
> --- a/drivers/platform/x86/lenovo/Makefile
> +++ b/drivers/platform/x86/lenovo/Makefile
> @@ -17,6 +17,7 @@ lenovo-target-$(CONFIG_LENOVO_WMI_EVENTS) += wmi-events.o
> lenovo-target-$(CONFIG_LENOVO_WMI_HELPERS) += wmi-helpers.o
> lenovo-target-$(CONFIG_LENOVO_WMI_GAMEZONE) += wmi-gamezone.o
> lenovo-target-$(CONFIG_LENOVO_WMI_TUNING) += wmi-other.o
> +lenovo-target-$(CONFIG_LENOVO_WMI_FAN_METHOD) += wmi-fan-method.o
>
> # Add 'lenovo' prefix to each module listed in lenovo-target-*
> define LENOVO_OBJ_TARGET
> diff --git a/drivers/platform/x86/lenovo/wmi-fan-method.c b/drivers/platform/x86/lenovo/wmi-fan-method.c
> new file mode 100644
> index 000000000000..4f29c4134caf
> --- /dev/null
> +++ b/drivers/platform/x86/lenovo/wmi-fan-method.c
> @@ -0,0 +1,380 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Lenovo Fan Method WMI interface driver.
> + *
> + * This driver exposes the firmware fan table through HWMON automatic-point
> + * attributes on selected Lenovo Legion Go products.
> + */
> +
> +#include <linux/cleanup.h>
> +#include <linux/component.h>
> +#include <linux/device.h>
> +#include <linux/dmi.h>
> +#include <linux/err.h>
> +#include <linux/kernel.h>
> +#include <linux/limits.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/sysfs.h>
> +#include <linux/types.h>
> +#include <linux/unaligned.h>
> +#include <linux/wmi.h>
> +
> +#define LENOVO_FAN_METHOD_GUID "92549549-4BDE-4F06-AC04-CE8BF898DBAA"
> +
> +#define LENOVO_FAN_METHOD_GET_CURVE 5
> +#define LENOVO_FAN_METHOD_SET_CURVE 6
> +#define LENOVO_FAN_CURVE_POINTS 10
> +#define LENOVO_FAN_CURVE_REPLY_SIZE 88
> +#define LENOVO_FAN_CURVE_WRITE_SIZE 64
> +
> +#define LENOVO_FAN_REPLY_SPEED_COUNT_OFFSET 0
> +#define LENOVO_FAN_REPLY_SPEED_OFFSET 4
> +#define LENOVO_FAN_REPLY_TEMP_COUNT_OFFSET 44
> +#define LENOVO_FAN_REPLY_TEMP_OFFSET 48
> +
> +#define LENOVO_FAN_WRITE_SPEED_COUNT_OFFSET 2
> +#define LENOVO_FAN_WRITE_SPEED_OFFSET 6
> +#define LENOVO_FAN_WRITE_TEMP_TYPE_OFFSET 26
> +#define LENOVO_FAN_WRITE_TEMP_COUNT_OFFSET 27
> +#define LENOVO_FAN_WRITE_TEMP_OFFSET 31
> +#define LENOVO_FAN_WRITE_TRAILER_OFFSET 51
> +#define LENOVO_FAN_WRITE_TRAILER_VALUE_OFFSET 53
> +
> +#define LENOVO_FAN_WRITE_TEMP_TYPE 1
> +#define LENOVO_FAN_WRITE_TRAILER 0x5a
> +#define LENOVO_FAN_WRITE_TRAILER_VALUE 100
> +
> +static const struct dmi_system_id lwmi_fan_dmi_table[] = {
> + {
> + .ident = "Lenovo Legion Go 8APU1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8APU1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go S 8APU1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go S 8APU1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go S 8ARP1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go S 8ARP1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go 8ASP2",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8ASP2"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go 8AHP2",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8AHP2"),
> + },
> + },
> + {}
> +};
Unless proven to be necessary, drop the dmi table. Autodetection
should suffice until devices are discovered with this functionality.
> +
> +static const u16 lwmi_fan_temperatures[LENOVO_FAN_CURVE_POINTS] = {
> + 10, 20, 30, 40, 50, 60, 70, 80, 90, 100
> +};
I think you should read those from WMI instead of hardcoding them.
Even though you should block writes as you do.
> +
> +struct lwmi_fan_method_curve {
> + u16 speed[LENOVO_FAN_CURVE_POINTS];
> + u16 temperature[LENOVO_FAN_CURVE_POINTS];
> +};
> +
> +struct lwmi_fan_method_priv;
> +
> +struct lwmi_fan_method_attr {
> + struct device_attribute dev_attr;
> + struct lwmi_fan_method_priv *priv;
> + u8 index;
> +};
> +
> +struct lwmi_fan_method_priv {
> + struct wmi_device *wdev;
> + struct mutex lock; /* Serializes all Fan Method calls. */
> + struct lwmi_fan_method_attr point_attrs[LENOVO_FAN_CURVE_POINTS * 2];
> + struct attribute *attrs[LENOVO_FAN_CURVE_POINTS * 2 + 1];
> + struct attribute_group group;
> +};
> +
> +static int lwmi_fan_method_get_curve(struct lwmi_fan_method_priv *priv,
> + struct lwmi_fan_method_curve *curve)
> +{
> + u8 input[] = { 1, 1 };
> + struct wmi_buffer in = {
> + .length = sizeof(input),
> + .data = input,
> + };
> + struct wmi_buffer out = {};
> + const u8 *buffer;
> + int ret, i;
> +
> + ret = wmidev_invoke_method(priv->wdev, 0,
> + LENOVO_FAN_METHOD_GET_CURVE, &in, &out,
> + LENOVO_FAN_CURVE_REPLY_SIZE);
> + if (ret)
> + return ret;
> +
> + buffer = out.data;
> + if (get_unaligned_le32(buffer + LENOVO_FAN_REPLY_SPEED_COUNT_OFFSET) !=
> + LENOVO_FAN_CURVE_POINTS ||
> + get_unaligned_le32(buffer + LENOVO_FAN_REPLY_TEMP_COUNT_OFFSET) !=
> + LENOVO_FAN_CURVE_POINTS) {
> + ret = -ERANGE;
> + goto out_free;
> + }
> +
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++) {
> + u32 speed = get_unaligned_le32(buffer + LENOVO_FAN_REPLY_SPEED_OFFSET +
> + i * sizeof(u32));
> + u32 temperature =
> + get_unaligned_le32(buffer + LENOVO_FAN_REPLY_TEMP_OFFSET +
> + i * sizeof(u32));
> +
> + if (speed > U8_MAX || temperature != lwmi_fan_temperatures[i]) {
> + ret = -ERANGE;
> + goto out_free;
> + }
> +
> + curve->speed[i] = speed;
> + curve->temperature[i] = temperature;
> + }
> +
> +out_free:
> + kfree(out.data);
> + return ret;
> +}
> +
> +static int lwmi_fan_method_set_curve(struct lwmi_fan_method_priv *priv,
> + const struct lwmi_fan_method_curve *curve)
> +{
> + u8 buffer[LENOVO_FAN_CURVE_WRITE_SIZE] = { 0xff, 0x01 };
> + struct wmi_buffer in = {
> + .length = sizeof(buffer),
> + .data = buffer,
> + };
> + int i;
> +
> + put_unaligned_le32(LENOVO_FAN_CURVE_POINTS,
> + buffer + LENOVO_FAN_WRITE_SPEED_COUNT_OFFSET);
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++)
> + put_unaligned_le16(curve->speed[i],
> + buffer + LENOVO_FAN_WRITE_SPEED_OFFSET +
> + i * sizeof(u16));
> +
> + buffer[LENOVO_FAN_WRITE_TEMP_TYPE_OFFSET] = LENOVO_FAN_WRITE_TEMP_TYPE;
> + put_unaligned_le32(LENOVO_FAN_CURVE_POINTS,
> + buffer + LENOVO_FAN_WRITE_TEMP_COUNT_OFFSET);
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++)
> + put_unaligned_le16(curve->temperature[i],
> + buffer + LENOVO_FAN_WRITE_TEMP_OFFSET +
> + i * sizeof(u16));
> +
> + buffer[LENOVO_FAN_WRITE_TRAILER_OFFSET] = LENOVO_FAN_WRITE_TRAILER;
> + put_unaligned_le16(LENOVO_FAN_WRITE_TRAILER_VALUE,
> + buffer + LENOVO_FAN_WRITE_TRAILER_VALUE_OFFSET);
> +
> + return wmidev_invoke_procedure(priv->wdev, 0,
> + LENOVO_FAN_METHOD_SET_CURVE, &in);
> +}
> +
> +static ssize_t lwmi_fan_method_pwm_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> + struct lwmi_fan_method_priv *priv = point_attr->priv;
> + struct lwmi_fan_method_curve curve;
> + int ret;
> +
> + guard(mutex)(&priv->lock);
> +
> + ret = lwmi_fan_method_get_curve(priv, &curve);
> + if (ret)
> + return ret;
> +
> + return sysfs_emit(buf, "%u\n", curve.speed[point_attr->index]);
> +}
> +
> +static ssize_t lwmi_fan_method_pwm_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> + struct lwmi_fan_method_priv *priv = point_attr->priv;
> + struct lwmi_fan_method_curve curve;
> + unsigned long pwm;
> + int ret;
> +
> + ret = kstrtoul(buf, 10, &pwm);
> + if (ret)
> + return ret;
> + if (pwm > U8_MAX)
> + return -EINVAL;
> +
> + guard(mutex)(&priv->lock);
> +
> + ret = lwmi_fan_method_get_curve(priv, &curve);
> + if (ret)
> + return ret;
> +
> + curve.speed[point_attr->index] = pwm;
> + ret = lwmi_fan_method_set_curve(priv, &curve);
> +
> + return ret ? ret : count;
> +}
> +
> +static ssize_t lwmi_fan_method_temp_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> +
> + return sysfs_emit(buf, "%u\n",
> + lwmi_fan_temperatures[point_attr->index] * 1000);
> +}
> +
> +#define LWMI_FAN_METHOD_POINT_NAMES(_point) \
> + "pwm1_auto_point" #_point "_pwm", \
> + "pwm1_auto_point" #_point "_temp"
> +
> +static const char * const lwmi_fan_method_attr_names[] = {
> + LWMI_FAN_METHOD_POINT_NAMES(1),
> + LWMI_FAN_METHOD_POINT_NAMES(2),
> + LWMI_FAN_METHOD_POINT_NAMES(3),
> + LWMI_FAN_METHOD_POINT_NAMES(4),
> + LWMI_FAN_METHOD_POINT_NAMES(5),
> + LWMI_FAN_METHOD_POINT_NAMES(6),
> + LWMI_FAN_METHOD_POINT_NAMES(7),
> + LWMI_FAN_METHOD_POINT_NAMES(8),
> + LWMI_FAN_METHOD_POINT_NAMES(9),
> + LWMI_FAN_METHOD_POINT_NAMES(10),
> +};
> +
> +#undef LWMI_FAN_METHOD_POINT_NAMES
> +
> +static void lwmi_fan_method_attrs_init(struct lwmi_fan_method_priv *priv)
> +{
> + int i;
> +
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++) {
> + struct lwmi_fan_method_attr *pwm = &priv->point_attrs[i * 2];
> + struct lwmi_fan_method_attr *temp = &priv->point_attrs[i * 2 + 1];
> +
> + sysfs_attr_init(&pwm->dev_attr.attr);
> + pwm->dev_attr.attr.name = lwmi_fan_method_attr_names[i * 2];
> + pwm->dev_attr.attr.mode = 0644;
> + pwm->dev_attr.show = lwmi_fan_method_pwm_show;
> + pwm->dev_attr.store = lwmi_fan_method_pwm_store;
> + pwm->priv = priv;
> + pwm->index = i;
> + priv->attrs[i * 2] = &pwm->dev_attr.attr;
> +
> + sysfs_attr_init(&temp->dev_attr.attr);
> + temp->dev_attr.attr.name = lwmi_fan_method_attr_names[i * 2 + 1];
> + temp->dev_attr.attr.mode = 0444;
> + temp->dev_attr.show = lwmi_fan_method_temp_show;
> + temp->index = i;
> + priv->attrs[i * 2 + 1] = &temp->dev_attr.attr;
> + }
> +
> + priv->group.attrs = priv->attrs;
> +}
> +
> +static int lwmi_fan_method_master_bind(struct device *dev)
> +{
> + struct lwmi_fan_method_priv *priv = dev_get_drvdata(dev);
> +
> + return component_bind_all(dev, &priv->group);
> +}
> +
> +static void lwmi_fan_method_master_unbind(struct device *dev)
> +{
> + component_unbind_all(dev, NULL);
> +}
> +
> +static const struct component_master_ops lwmi_fan_method_master_ops = {
> + .bind = lwmi_fan_method_master_bind,
> + .unbind = lwmi_fan_method_master_unbind,
> +};
> +
> +static int lwmi_fan_method_component_compare(struct device *dev, void *data)
> +{
> + struct device *master = data;
> +
> + return dev->driver &&
> + !strcmp(dev->driver->name, "lenovo_wmi_other") &&
> + dev->parent == master->parent;
> +}
> +
> +static int lwmi_fan_method_probe(struct wmi_device *wdev, const void *context)
> +{
> + struct component_match *master_match = NULL;
> + struct lwmi_fan_method_priv *priv;
> +
> + if (!dmi_check_system(lwmi_fan_dmi_table))
> + return -ENODEV;
> +
> + priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->wdev = wdev;
> + mutex_init(&priv->lock);
> + lwmi_fan_method_attrs_init(priv);
> + dev_set_drvdata(&wdev->dev, priv);
> +
> + component_match_add(&wdev->dev, &master_match,
> + lwmi_fan_method_component_compare, &wdev->dev);
> + if (IS_ERR(master_match))
> + return PTR_ERR(master_match);
> +
> + return component_master_add_with_match(&wdev->dev,
> + &lwmi_fan_method_master_ops,
> + master_match);
> +}
> +
> +static void lwmi_fan_method_remove(struct wmi_device *wdev)
> +{
> + component_master_del(&wdev->dev, &lwmi_fan_method_master_ops);
> +}
> +
> +static const struct wmi_device_id lwmi_fan_method_id_table[] = {
> + { LENOVO_FAN_METHOD_GUID, NULL },
> + {}
> +};
> +
> +static struct wmi_driver lwmi_fan_method_driver = {
> + .driver = {
> + .name = "lenovo_wmi_fan_method",
I chose the name lenovo_wmi_gamezone_fan as its more explanatory, consider that
> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> + },
> + .id_table = lwmi_fan_method_id_table,
> + .probe = lwmi_fan_method_probe,
> + .remove = lwmi_fan_method_remove,
> + .no_singleton = true,
> +};
> +
> +MODULE_DEVICE_TABLE(wmi, lwmi_fan_method_id_table);
> +module_wmi_driver(lwmi_fan_method_driver);
> +
> +MODULE_AUTHOR("Aditya Dash <mradityadash@gmail.com>");
> +MODULE_DESCRIPTION("Lenovo Fan Method WMI Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
> index b4be7739b243..72d3510b17b2 100644
> --- a/drivers/platform/x86/lenovo/wmi-other.c
> +++ b/drivers/platform/x86/lenovo/wmi-other.c
You cannot modify other drivers in the patch you introduce your
driver. If modifying wmi-other is necessary, please do it on a
separate patch leading this one with a proper explanation.
Particularly, it is not clear why we need to couple wmi-other, the
interfaces are separate. To keep the coupling simple, ideally this
driver should be standalone and not check anything. Yes, technically
only custom mode should be able to set the fan curve, but it works on
all modes for a variety of firmwares / devices so this is a loss of
functionality, and it also forces you to couple to gamezone.
> @@ -192,11 +192,13 @@ struct lwmi_om_priv {
> struct device *fw_attr_dev;
> struct kset *fw_attr_kset;
> struct wmi_device *wdev;
> + const struct attribute_group *fan_method_group;
> int ida_id;
>
> struct lwmi_fan_info fan_info[LWMI_FAN_NR];
> bool fullspeed_supported;
> bool fan0_input_fallback;
> + bool fan_method_group_added;
>
> struct {
> bool capdata00_collected : 1;
> @@ -542,6 +544,31 @@ static const struct hwmon_chip_info lwmi_om_hwmon_chip_info = {
> .info = lwmi_om_hwmon_info,
> };
>
> +static int lwmi_om_fan_method_group_add(struct lwmi_om_priv *priv)
> +{
> + int ret;
> +
> + if (!priv->hwmon_dev || !priv->fan_method_group ||
> + priv->fan_method_group_added)
> + return 0;
> +
> + ret = sysfs_create_group(&priv->hwmon_dev->kobj,
> + priv->fan_method_group);
> + if (!ret)
> + priv->fan_method_group_added = true;
> +
> + return ret;
> +}
> +
> +static void lwmi_om_fan_method_group_remove(struct lwmi_om_priv *priv)
> +{
> + if (!priv->hwmon_dev || !priv->fan_method_group_added)
> + return;
> +
> + sysfs_remove_group(&priv->hwmon_dev->kobj, priv->fan_method_group);
> + priv->fan_method_group_added = false;
> +}
> +
> /**
> * lwmi_om_hwmon_add() - Register HWMON device if all info is collected
> * @priv: Driver private data
> @@ -550,9 +577,9 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> {
> u32 rpm;
> long enable;
> - int i, valid;
> + int i, ret, valid;
>
> - if (WARN_ON(priv->hwmon_dev))
> + if (priv->hwmon_dev)
> return;
>
> if (!priv->fan_flags.capdata00_collected || !priv->fan_flags.capdata_fan_collected) {
> @@ -592,7 +619,8 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> }
> }
>
> - if (valid == 0 && !priv->fullspeed_supported && !priv->fan0_input_fallback) {
> + if (valid == 0 && !priv->fullspeed_supported &&
> + !priv->fan0_input_fallback && !priv->fan_method_group) {
> dev_warn(&priv->wdev->dev,
> "fan reporting/tuning is unsupported on this device\n");
> return;
> @@ -609,6 +637,11 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> return;
> }
>
> + ret = lwmi_om_fan_method_group_add(priv);
> + if (ret)
> + dev_warn(&priv->wdev->dev,
> + "failed to register Fan Method attributes: %d\n", ret);
> +
> dev_dbg(&priv->wdev->dev, "registered HWMON device\n");
> }
>
> @@ -623,6 +656,7 @@ static void lwmi_om_hwmon_remove(struct lwmi_om_priv *priv)
> if (!priv->hwmon_dev)
> return;
>
> + lwmi_om_fan_method_group_remove(priv);
> hwmon_device_unregister(priv->hwmon_dev);
> priv->hwmon_dev = NULL;
> }
> @@ -1801,10 +1835,44 @@ static const struct component_master_ops lwmi_om_master_ops = {
> .unbind = lwmi_om_master_unbind,
> };
>
> +static int lwmi_om_fan_method_component_bind(struct device *component,
> + struct device *master, void *data)
> +{
> + const struct attribute_group *group = data;
> + struct lwmi_om_priv *priv = dev_get_drvdata(component);
> + int ret;
> +
> + if (!group)
> + return -EINVAL;
> +
> + priv->fan_method_group = group;
> + lwmi_om_hwmon_add(priv);
> + ret = lwmi_om_fan_method_group_add(priv);
> + if (ret)
> + priv->fan_method_group = NULL;
> +
> + return ret;
> +}
> +
> +static void lwmi_om_fan_method_component_unbind(struct device *component,
> + struct device *master, void *data)
> +{
> + struct lwmi_om_priv *priv = dev_get_drvdata(component);
> +
> + lwmi_om_fan_method_group_remove(priv);
> + priv->fan_method_group = NULL;
> +}
> +
> +static const struct component_ops lwmi_om_fan_method_component_ops = {
> + .bind = lwmi_om_fan_method_component_bind,
> + .unbind = lwmi_om_fan_method_component_unbind,
> +};
> +
> static int lwmi_other_probe(struct wmi_device *wdev, const void *context)
> {
> struct component_match *master_match = NULL;
> struct lwmi_om_priv *priv;
> + int ret;
>
> priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> if (!priv)
> @@ -1816,16 +1884,31 @@ static int lwmi_other_probe(struct wmi_device *wdev, const void *context)
> priv->wdev = wdev;
> dev_set_drvdata(&wdev->dev, priv);
>
> + ret = component_add(&wdev->dev, &lwmi_om_fan_method_component_ops);
> + if (ret)
> + return ret;
> +
> lwmi_cd_match_add_all(&wdev->dev, &master_match);
> - if (IS_ERR(master_match))
> - return PTR_ERR(master_match);
> + if (IS_ERR(master_match)) {
> + ret = PTR_ERR(master_match);
> + goto err_component;
> + }
> +
> + ret = component_master_add_with_match(&wdev->dev, &lwmi_om_master_ops,
> + master_match);
> + if (ret)
> + goto err_component;
> +
> + return 0;
>
> - return component_master_add_with_match(&wdev->dev, &lwmi_om_master_ops,
> - master_match);
> +err_component:
> + component_del(&wdev->dev, &lwmi_om_fan_method_component_ops);
> + return ret;
> }
>
> static void lwmi_other_remove(struct wmi_device *wdev)
> {
> + component_del(&wdev->dev, &lwmi_om_fan_method_component_ops);
> component_master_del(&wdev->dev, &lwmi_om_master_ops);
> }
You may reference the following commit and the 4-5 preceding ones to
see if they help you:
https://github.com/anatase-org/patchwork/commit/71925109610c9753504ab43b3a09aa60058f8829
Specifically, this is my version to your patch:
https://github.com/anatase-org/patchwork/commit/718c90474b89b3e931af9255c00c8e4c76ddf32e
Perhaps it is a bit more straightforward.
>
> --
> 2.55.0
>
^ permalink raw reply [flat|nested] 18+ messages in thread* Re: [RFC PATCH 3/3] platform/x86: lenovo: Add Legion Go Fan Method curve driver
2026-08-21 21:47 ` [RFC PATCH 3/3] platform/x86: lenovo: Add Legion Go Fan Method curve driver Aditya Dash
2026-08-22 18:47 ` Antheas Kapenekakis
@ 2026-08-23 21:09 ` Rong Zhang
2026-08-24 8:10 ` Ilpo Järvinen
2026-08-25 19:34 ` Derek John Clark
3 siblings, 0 replies; 18+ messages in thread
From: Rong Zhang @ 2026-08-23 21:09 UTC (permalink / raw)
To: Aditya Dash, Derek J. Clark, Ilpo Järvinen, Armin Wolf,
Hans de Goede, Mark Pearson
Cc: Guenter Roeck, Jonathan Corbet, Shuah Khan, linux-doc,
linux-hwmon, linux-kernel, platform-driver-x86
Hi Aditya,
On Sat, 2026-08-22 at 03:17 +0530, Aditya Dash wrote:
> Legion Go firmware keeps its custom fan curve in a separate Fan Method WMI
> interface. Method 5 returns ten control values and ten temperatures, while
> Method 6 replaces the complete table.
>
> The GUID also appears on Lenovo systems with a different table layout.
What does the different table layout look like?
> Limit the driver to Legion Go 8APU1, Legion Go 8ASP2, Legion Go 8AHP2,
> Legion Go S 8ARP1, and Legion Go S 8APU1 products. These products use the
> same ten-point layout and Method 6 request.
>
> The curve applies to the same fan as the existing Other Mode attributes.
> Add a separate WMI driver and attach the ten automatic-point pairs to the
> HWMON device that Other Mode already provides. Match devices from the same
> WMI provider. Other Mode continues to work without Fan Method. Probe does
> not invoke either method.
>
> Validate both counts, every control value, and the complete temperature
> table before using a Method 5 reply. A point write holds the mutex while
> it reads the current table, changes one control value, and submits the
> complete Method 6 request. The other values remain unchanged.
>
> The HWMON mapping is not clear. On the tested Legion Go 8APU1, the fan
> responds to values from 0 through 115. This is Lenovo's 0 through 115
> percent range. Lenovo software shows 0 through 100 percent to the user,
> and 115 reaches the RPM observed in Full Speed mode. Firmware accepts
> values through 255, but values above 115 caused no observed RPM increase.
>
> This RFC exposes the firmware values unchanged. The fixed temperatures are
> read-only.
>
> Assisted-by: Pi:gpt-5.6-sol
> Signed-off-by: Aditya Dash <mradityadash@gmail.com>
> ---
> .../wmi/devices/lenovo-wmi-fan-method.rst | 34 ++
> .../wmi/devices/lenovo-wmi-other.rst | 3 +
> MAINTAINERS | 1 +
> drivers/platform/x86/lenovo/Kconfig | 11 +
> drivers/platform/x86/lenovo/Makefile | 1 +
> drivers/platform/x86/lenovo/wmi-fan-method.c | 380 ++++++++++++++++++
> drivers/platform/x86/lenovo/wmi-other.c | 97 ++++-
> 7 files changed, 520 insertions(+), 7 deletions(-)
> create mode 100644 Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> create mode 100644 drivers/platform/x86/lenovo/wmi-fan-method.c
>
> diff --git a/Documentation/wmi/devices/lenovo-wmi-fan-method.rst b/Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> new file mode 100644
> index 000000000000..67c9a92ed992
> --- /dev/null
> +++ b/Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> @@ -0,0 +1,34 @@
> +.. SPDX-License-Identifier: GPL-2.0-or-later
> +
> +==================================
> +Lenovo Fan Method WMI Driver
> +==================================
> +
> +WMI GUID ``92549549-4BDE-4F06-AC04-CE8BF898DBAA``
> +
> +The Lenovo Fan Method interface provides a ten-point firmware fan table on
> +Legion Go 8APU1, Legion Go 8ASP2, Legion Go 8AHP2, Legion Go S 8ARP1, and
> +Legion Go S 8APU1 products.
> +
> +The driver adds ``pwm1_auto_point1_*`` through
> +``pwm1_auto_point10_*`` to the HWMON device that the Lenovo Other Mode driver
> +owns. The temperature attributes are fixed and read-only. They contain points
> +from 10 through 100 degrees Celsius in 10-degree steps.
> +
> +Each ``pwm1_auto_point*_pwm`` attribute is read-write and passes a firmware
> +control value from 0 through 255 without scaling. On the tested Legion Go
> +8APU1, the hardware responds from 0 through 115, corresponding to Lenovo's
> +0 through 115 percent range. Lenovo software shows 0 through 100 percent to
> +the user, and 115 percent reaches the RPM observed in Full Speed mode. The
> +firmware accepts values through 255, but values above 115 caused no observed
> +RPM increase.
> +
> +A control-value read validates both ten-entry tables before returning data. A
> +point write reads the current table, changes one control value, and submits the
> +complete request. It preserves the other nine control values and all returned
> +temperatures.
> +
> +The Fan Method and Other Mode drivers use separate modules and WMI devices.
> +The component framework associates devices that belong to the same WMI
> +provider. Fan Method curve attributes are absent when either interface is not
> +available.
> diff --git a/Documentation/wmi/devices/lenovo-wmi-other.rst b/Documentation/wmi/devices/lenovo-wmi-other.rst
> index c93e9e6f3fd0..34352dbd6fb9 100644
> --- a/Documentation/wmi/devices/lenovo-wmi-other.rst
> +++ b/Documentation/wmi/devices/lenovo-wmi-other.rst
> @@ -60,6 +60,9 @@ Some Legion Go firmware does not advertise fan 1 RPM through Capability
> Data. In that case, the driver reads Other Mode feature ``0x04030001`` for
> ``fan1_input``. Value ``0xffffffff`` means that RPM is unavailable.
>
> +When the separate Lenovo Fan Method driver binds to the same WMI provider, it
> +adds ten automatic fan-curve points to this HWMON device.
> +
> LENOVO_CAPABILITY_DATA_01
> -------------------------
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3820b286f09f..8612c2323540 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14689,6 +14689,7 @@ M: Mark Pearson <mpearson-lenovo@squebb.ca>
> M: Derek J. Clark <derekjohn.clark@gmail.com>
> L: platform-driver-x86@vger.kernel.org
> S: Maintained
> +F: Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> F: Documentation/wmi/devices/lenovo-wmi-gamezone.rst
> F: Documentation/wmi/devices/lenovo-wmi-other.rst
> F: drivers/platform/x86/lenovo/*
> diff --git a/drivers/platform/x86/lenovo/Kconfig b/drivers/platform/x86/lenovo/Kconfig
> index 4443f40ef8aa..e69942ce3093 100644
> --- a/drivers/platform/x86/lenovo/Kconfig
> +++ b/drivers/platform/x86/lenovo/Kconfig
> @@ -276,3 +276,14 @@ config LENOVO_WMI_TUNING
>
> To compile this driver as a module, choose M here: the module will
> be called lenovo-wmi-other.
> +
> +config LENOVO_WMI_FAN_METHOD
> + tristate "Lenovo Fan Method WMI Driver"
> + depends on DMI
> + depends on LENOVO_WMI_TUNING
> + help
> + Say Y here to add the firmware fan table on supported Lenovo
> + Legion Go products to the Lenovo Other Mode HWMON device.
> +
> + To compile this driver as a module, choose M here: the module will
> + be called lenovo-wmi-fan-method.
> diff --git a/drivers/platform/x86/lenovo/Makefile b/drivers/platform/x86/lenovo/Makefile
> index 91a9370f11b3..171a19e01479 100644
> --- a/drivers/platform/x86/lenovo/Makefile
> +++ b/drivers/platform/x86/lenovo/Makefile
> @@ -17,6 +17,7 @@ lenovo-target-$(CONFIG_LENOVO_WMI_EVENTS) += wmi-events.o
> lenovo-target-$(CONFIG_LENOVO_WMI_HELPERS) += wmi-helpers.o
> lenovo-target-$(CONFIG_LENOVO_WMI_GAMEZONE) += wmi-gamezone.o
> lenovo-target-$(CONFIG_LENOVO_WMI_TUNING) += wmi-other.o
> +lenovo-target-$(CONFIG_LENOVO_WMI_FAN_METHOD) += wmi-fan-method.o
>
> # Add 'lenovo' prefix to each module listed in lenovo-target-*
> define LENOVO_OBJ_TARGET
> diff --git a/drivers/platform/x86/lenovo/wmi-fan-method.c b/drivers/platform/x86/lenovo/wmi-fan-method.c
> new file mode 100644
> index 000000000000..4f29c4134caf
> --- /dev/null
> +++ b/drivers/platform/x86/lenovo/wmi-fan-method.c
> @@ -0,0 +1,380 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Lenovo Fan Method WMI interface driver.
> + *
> + * This driver exposes the firmware fan table through HWMON automatic-point
> + * attributes on selected Lenovo Legion Go products.
> + */
> +
> +#include <linux/cleanup.h>
> +#include <linux/component.h>
> +#include <linux/device.h>
> +#include <linux/dmi.h>
> +#include <linux/err.h>
> +#include <linux/kernel.h>
> +#include <linux/limits.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/sysfs.h>
> +#include <linux/types.h>
> +#include <linux/unaligned.h>
> +#include <linux/wmi.h>
> +
> +#define LENOVO_FAN_METHOD_GUID "92549549-4BDE-4F06-AC04-CE8BF898DBAA"
> +
> +#define LENOVO_FAN_METHOD_GET_CURVE 5
> +#define LENOVO_FAN_METHOD_SET_CURVE 6
> +#define LENOVO_FAN_CURVE_POINTS 10
> +#define LENOVO_FAN_CURVE_REPLY_SIZE 88
> +#define LENOVO_FAN_CURVE_WRITE_SIZE 64
> +
> +#define LENOVO_FAN_REPLY_SPEED_COUNT_OFFSET 0
> +#define LENOVO_FAN_REPLY_SPEED_OFFSET 4
> +#define LENOVO_FAN_REPLY_TEMP_COUNT_OFFSET 44
> +#define LENOVO_FAN_REPLY_TEMP_OFFSET 48
> +
> +#define LENOVO_FAN_WRITE_SPEED_COUNT_OFFSET 2
> +#define LENOVO_FAN_WRITE_SPEED_OFFSET 6
> +#define LENOVO_FAN_WRITE_TEMP_TYPE_OFFSET 26
> +#define LENOVO_FAN_WRITE_TEMP_COUNT_OFFSET 27
> +#define LENOVO_FAN_WRITE_TEMP_OFFSET 31
> +#define LENOVO_FAN_WRITE_TRAILER_OFFSET 51
> +#define LENOVO_FAN_WRITE_TRAILER_VALUE_OFFSET 53
I don't like defining so many offsets here.
And this just overfits LENOVO_FAN_CURVE_POINTS == 10, doesn't it? LLMs
tend to overfit various things, sigh.
It would be super painful when adding support for devices with
LENOVO_FAN_CURVE_POINTS != 10, so please don't overfit that.
> +
> +#define LENOVO_FAN_WRITE_TEMP_TYPE 1
> +#define LENOVO_FAN_WRITE_TRAILER 0x5a
> +#define LENOVO_FAN_WRITE_TRAILER_VALUE 100
> +
> +static const struct dmi_system_id lwmi_fan_dmi_table[] = {
> + {
> + .ident = "Lenovo Legion Go 8APU1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8APU1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go S 8APU1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go S 8APU1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go S 8ARP1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go S 8ARP1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go 8ASP2",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8ASP2"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go 8AHP2",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8AHP2"),
> + },
> + },
> + {}
> +};
> +
> +static const u16 lwmi_fan_temperatures[LENOVO_FAN_CURVE_POINTS] = {
> + 10, 20, 30, 40, 50, 60, 70, 80, 90, 100
> +};
65535 degree Celsius is too hot. Just use u8.
> +
> +struct lwmi_fan_method_curve {
> + u16 speed[LENOVO_FAN_CURVE_POINTS];
> + u16 temperature[LENOVO_FAN_CURVE_POINTS];
Ditto.
> +};
> +
> +struct lwmi_fan_method_priv;
> +
> +struct lwmi_fan_method_attr {
> + struct device_attribute dev_attr;
> + struct lwmi_fan_method_priv *priv;
> + u8 index;
> +};
> +
> +struct lwmi_fan_method_priv {
> + struct wmi_device *wdev;
> + struct mutex lock; /* Serializes all Fan Method calls. */
> + struct lwmi_fan_method_attr point_attrs[LENOVO_FAN_CURVE_POINTS * 2];
> + struct attribute *attrs[LENOVO_FAN_CURVE_POINTS * 2 + 1];
> + struct attribute_group group;
> +};
> +
> +static int lwmi_fan_method_get_curve(struct lwmi_fan_method_priv *priv,
> + struct lwmi_fan_method_curve *curve)
> +{
> + u8 input[] = { 1, 1 };
> + struct wmi_buffer in = {
> + .length = sizeof(input),
> + .data = input,
> + };
> + struct wmi_buffer out = {};
> + const u8 *buffer;
> + int ret, i;
> +
> + ret = wmidev_invoke_method(priv->wdev, 0,
> + LENOVO_FAN_METHOD_GET_CURVE, &in, &out,
> + LENOVO_FAN_CURVE_REPLY_SIZE);
> + if (ret)
> + return ret;
> +
> + buffer = out.data;
> + if (get_unaligned_le32(buffer + LENOVO_FAN_REPLY_SPEED_COUNT_OFFSET) !=
> + LENOVO_FAN_CURVE_POINTS ||
> + get_unaligned_le32(buffer + LENOVO_FAN_REPLY_TEMP_COUNT_OFFSET) !=
> + LENOVO_FAN_CURVE_POINTS) {
> + ret = -ERANGE;
> + goto out_free;
> + }
Don't overfit...
> +
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++) {
> + u32 speed = get_unaligned_le32(buffer + LENOVO_FAN_REPLY_SPEED_OFFSET +
> + i * sizeof(u32));
> + u32 temperature =
> + get_unaligned_le32(buffer + LENOVO_FAN_REPLY_TEMP_OFFSET +
> + i * sizeof(u32));
Please check how lwmi_cd_fan_list_alloc_cache() gets rid of hard-coded
offsets.
> +
> + if (speed > U8_MAX || temperature != lwmi_fan_temperatures[i]) {
> + ret = -ERANGE;
> + goto out_free;
> + }
Why would you need to enforce temperature == lwmi_fan_temperatures[i]?
You can expose the FW temperature table to userspace via
/sys/class/hwmon/hwmonX/pwmY_auto_pointZ_temp.
> +
> + curve->speed[i] = speed;
If speed is always less than or equal to U8_MAX, please convert the array
into a u8 one.
> + curve->temperature[i] = temperature;
> + }
> +
> +out_free:
> + kfree(out.data);
Use cleanup.h __free(). See also lwmi_cd_fan_list_alloc_cache().
> + return ret;
> +}
> +
> +static int lwmi_fan_method_set_curve(struct lwmi_fan_method_priv *priv,
> + const struct lwmi_fan_method_curve *curve)
> +{
> + u8 buffer[LENOVO_FAN_CURVE_WRITE_SIZE] = { 0xff, 0x01 };
> + struct wmi_buffer in = {
> + .length = sizeof(buffer),
> + .data = buffer,
> + };
> + int i;
> +
> + put_unaligned_le32(LENOVO_FAN_CURVE_POINTS,
> + buffer + LENOVO_FAN_WRITE_SPEED_COUNT_OFFSET);
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++)
> + put_unaligned_le16(curve->speed[i],
> + buffer + LENOVO_FAN_WRITE_SPEED_OFFSET +
> + i * sizeof(u16));
> +
> + buffer[LENOVO_FAN_WRITE_TEMP_TYPE_OFFSET] = LENOVO_FAN_WRITE_TEMP_TYPE;
> + put_unaligned_le32(LENOVO_FAN_CURVE_POINTS,
> + buffer + LENOVO_FAN_WRITE_TEMP_COUNT_OFFSET);
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++)
> + put_unaligned_le16(curve->temperature[i],
> + buffer + LENOVO_FAN_WRITE_TEMP_OFFSET +
> + i * sizeof(u16));
> +
> + buffer[LENOVO_FAN_WRITE_TRAILER_OFFSET] = LENOVO_FAN_WRITE_TRAILER;
> + put_unaligned_le16(LENOVO_FAN_WRITE_TRAILER_VALUE,
> + buffer + LENOVO_FAN_WRITE_TRAILER_VALUE_OFFSET);
> +
> + return wmidev_invoke_procedure(priv->wdev, 0,
> + LENOVO_FAN_METHOD_SET_CURVE, &in);
> +}
What a hard-coded offset soup...
I will continue reviewing the series when you drop hard-coded offsets and
stop overfitting specific devices in the next revision.
Thanks,
Rong
> +
> +static ssize_t lwmi_fan_method_pwm_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> + struct lwmi_fan_method_priv *priv = point_attr->priv;
> + struct lwmi_fan_method_curve curve;
> + int ret;
> +
> + guard(mutex)(&priv->lock);
> +
> + ret = lwmi_fan_method_get_curve(priv, &curve);
> + if (ret)
> + return ret;
> +
> + return sysfs_emit(buf, "%u\n", curve.speed[point_attr->index]);
> +}
> +
> +static ssize_t lwmi_fan_method_pwm_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> + struct lwmi_fan_method_priv *priv = point_attr->priv;
> + struct lwmi_fan_method_curve curve;
> + unsigned long pwm;
> + int ret;
> +
> + ret = kstrtoul(buf, 10, &pwm);
> + if (ret)
> + return ret;
> + if (pwm > U8_MAX)
> + return -EINVAL;
> +
> + guard(mutex)(&priv->lock);
> +
> + ret = lwmi_fan_method_get_curve(priv, &curve);
> + if (ret)
> + return ret;
> +
> + curve.speed[point_attr->index] = pwm;
> + ret = lwmi_fan_method_set_curve(priv, &curve);
> +
> + return ret ? ret : count;
> +}
> +
> +static ssize_t lwmi_fan_method_temp_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> +
> + return sysfs_emit(buf, "%u\n",
> + lwmi_fan_temperatures[point_attr->index] * 1000);
> +}
> +
> +#define LWMI_FAN_METHOD_POINT_NAMES(_point) \
> + "pwm1_auto_point" #_point "_pwm", \
> + "pwm1_auto_point" #_point "_temp"
> +
> +static const char * const lwmi_fan_method_attr_names[] = {
> + LWMI_FAN_METHOD_POINT_NAMES(1),
> + LWMI_FAN_METHOD_POINT_NAMES(2),
> + LWMI_FAN_METHOD_POINT_NAMES(3),
> + LWMI_FAN_METHOD_POINT_NAMES(4),
> + LWMI_FAN_METHOD_POINT_NAMES(5),
> + LWMI_FAN_METHOD_POINT_NAMES(6),
> + LWMI_FAN_METHOD_POINT_NAMES(7),
> + LWMI_FAN_METHOD_POINT_NAMES(8),
> + LWMI_FAN_METHOD_POINT_NAMES(9),
> + LWMI_FAN_METHOD_POINT_NAMES(10),
> +};
> +
> +#undef LWMI_FAN_METHOD_POINT_NAMES
> +
> +static void lwmi_fan_method_attrs_init(struct lwmi_fan_method_priv *priv)
> +{
> + int i;
> +
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++) {
> + struct lwmi_fan_method_attr *pwm = &priv->point_attrs[i * 2];
> + struct lwmi_fan_method_attr *temp = &priv->point_attrs[i * 2 + 1];
> +
> + sysfs_attr_init(&pwm->dev_attr.attr);
> + pwm->dev_attr.attr.name = lwmi_fan_method_attr_names[i * 2];
> + pwm->dev_attr.attr.mode = 0644;
> + pwm->dev_attr.show = lwmi_fan_method_pwm_show;
> + pwm->dev_attr.store = lwmi_fan_method_pwm_store;
> + pwm->priv = priv;
> + pwm->index = i;
> + priv->attrs[i * 2] = &pwm->dev_attr.attr;
> +
> + sysfs_attr_init(&temp->dev_attr.attr);
> + temp->dev_attr.attr.name = lwmi_fan_method_attr_names[i * 2 + 1];
> + temp->dev_attr.attr.mode = 0444;
> + temp->dev_attr.show = lwmi_fan_method_temp_show;
> + temp->index = i;
> + priv->attrs[i * 2 + 1] = &temp->dev_attr.attr;
> + }
> +
> + priv->group.attrs = priv->attrs;
> +}
> +
> +static int lwmi_fan_method_master_bind(struct device *dev)
> +{
> + struct lwmi_fan_method_priv *priv = dev_get_drvdata(dev);
> +
> + return component_bind_all(dev, &priv->group);
> +}
> +
> +static void lwmi_fan_method_master_unbind(struct device *dev)
> +{
> + component_unbind_all(dev, NULL);
> +}
> +
> +static const struct component_master_ops lwmi_fan_method_master_ops = {
> + .bind = lwmi_fan_method_master_bind,
> + .unbind = lwmi_fan_method_master_unbind,
> +};
> +
> +static int lwmi_fan_method_component_compare(struct device *dev, void *data)
> +{
> + struct device *master = data;
> +
> + return dev->driver &&
> + !strcmp(dev->driver->name, "lenovo_wmi_other") &&
> + dev->parent == master->parent;
> +}
> +
> +static int lwmi_fan_method_probe(struct wmi_device *wdev, const void *context)
> +{
> + struct component_match *master_match = NULL;
> + struct lwmi_fan_method_priv *priv;
> +
> + if (!dmi_check_system(lwmi_fan_dmi_table))
> + return -ENODEV;
> +
> + priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->wdev = wdev;
> + mutex_init(&priv->lock);
> + lwmi_fan_method_attrs_init(priv);
> + dev_set_drvdata(&wdev->dev, priv);
> +
> + component_match_add(&wdev->dev, &master_match,
> + lwmi_fan_method_component_compare, &wdev->dev);
> + if (IS_ERR(master_match))
> + return PTR_ERR(master_match);
> +
> + return component_master_add_with_match(&wdev->dev,
> + &lwmi_fan_method_master_ops,
> + master_match);
> +}
> +
> +static void lwmi_fan_method_remove(struct wmi_device *wdev)
> +{
> + component_master_del(&wdev->dev, &lwmi_fan_method_master_ops);
> +}
> +
> +static const struct wmi_device_id lwmi_fan_method_id_table[] = {
> + { LENOVO_FAN_METHOD_GUID, NULL },
> + {}
> +};
> +
> +static struct wmi_driver lwmi_fan_method_driver = {
> + .driver = {
> + .name = "lenovo_wmi_fan_method",
> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> + },
> + .id_table = lwmi_fan_method_id_table,
> + .probe = lwmi_fan_method_probe,
> + .remove = lwmi_fan_method_remove,
> + .no_singleton = true,
> +};
> +
> +MODULE_DEVICE_TABLE(wmi, lwmi_fan_method_id_table);
> +module_wmi_driver(lwmi_fan_method_driver);
> +
> +MODULE_AUTHOR("Aditya Dash <mradityadash@gmail.com>");
> +MODULE_DESCRIPTION("Lenovo Fan Method WMI Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
> index b4be7739b243..72d3510b17b2 100644
> --- a/drivers/platform/x86/lenovo/wmi-other.c
> +++ b/drivers/platform/x86/lenovo/wmi-other.c
> @@ -192,11 +192,13 @@ struct lwmi_om_priv {
> struct device *fw_attr_dev;
> struct kset *fw_attr_kset;
> struct wmi_device *wdev;
> + const struct attribute_group *fan_method_group;
> int ida_id;
>
> struct lwmi_fan_info fan_info[LWMI_FAN_NR];
> bool fullspeed_supported;
> bool fan0_input_fallback;
> + bool fan_method_group_added;
>
> struct {
> bool capdata00_collected : 1;
> @@ -542,6 +544,31 @@ static const struct hwmon_chip_info lwmi_om_hwmon_chip_info = {
> .info = lwmi_om_hwmon_info,
> };
>
> +static int lwmi_om_fan_method_group_add(struct lwmi_om_priv *priv)
> +{
> + int ret;
> +
> + if (!priv->hwmon_dev || !priv->fan_method_group ||
> + priv->fan_method_group_added)
> + return 0;
> +
> + ret = sysfs_create_group(&priv->hwmon_dev->kobj,
> + priv->fan_method_group);
> + if (!ret)
> + priv->fan_method_group_added = true;
> +
> + return ret;
> +}
> +
> +static void lwmi_om_fan_method_group_remove(struct lwmi_om_priv *priv)
> +{
> + if (!priv->hwmon_dev || !priv->fan_method_group_added)
> + return;
> +
> + sysfs_remove_group(&priv->hwmon_dev->kobj, priv->fan_method_group);
> + priv->fan_method_group_added = false;
> +}
> +
> /**
> * lwmi_om_hwmon_add() - Register HWMON device if all info is collected
> * @priv: Driver private data
> @@ -550,9 +577,9 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> {
> u32 rpm;
> long enable;
> - int i, valid;
> + int i, ret, valid;
>
> - if (WARN_ON(priv->hwmon_dev))
> + if (priv->hwmon_dev)
> return;
>
> if (!priv->fan_flags.capdata00_collected || !priv->fan_flags.capdata_fan_collected) {
> @@ -592,7 +619,8 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> }
> }
>
> - if (valid == 0 && !priv->fullspeed_supported && !priv->fan0_input_fallback) {
> + if (valid == 0 && !priv->fullspeed_supported &&
> + !priv->fan0_input_fallback && !priv->fan_method_group) {
> dev_warn(&priv->wdev->dev,
> "fan reporting/tuning is unsupported on this device\n");
> return;
> @@ -609,6 +637,11 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> return;
> }
>
> + ret = lwmi_om_fan_method_group_add(priv);
> + if (ret)
> + dev_warn(&priv->wdev->dev,
> + "failed to register Fan Method attributes: %d\n", ret);
> +
> dev_dbg(&priv->wdev->dev, "registered HWMON device\n");
> }
>
> @@ -623,6 +656,7 @@ static void lwmi_om_hwmon_remove(struct lwmi_om_priv *priv)
> if (!priv->hwmon_dev)
> return;
>
> + lwmi_om_fan_method_group_remove(priv);
> hwmon_device_unregister(priv->hwmon_dev);
> priv->hwmon_dev = NULL;
> }
> @@ -1801,10 +1835,44 @@ static const struct component_master_ops lwmi_om_master_ops = {
> .unbind = lwmi_om_master_unbind,
> };
>
> +static int lwmi_om_fan_method_component_bind(struct device *component,
> + struct device *master, void *data)
> +{
> + const struct attribute_group *group = data;
> + struct lwmi_om_priv *priv = dev_get_drvdata(component);
> + int ret;
> +
> + if (!group)
> + return -EINVAL;
> +
> + priv->fan_method_group = group;
> + lwmi_om_hwmon_add(priv);
> + ret = lwmi_om_fan_method_group_add(priv);
> + if (ret)
> + priv->fan_method_group = NULL;
> +
> + return ret;
> +}
> +
> +static void lwmi_om_fan_method_component_unbind(struct device *component,
> + struct device *master, void *data)
> +{
> + struct lwmi_om_priv *priv = dev_get_drvdata(component);
> +
> + lwmi_om_fan_method_group_remove(priv);
> + priv->fan_method_group = NULL;
> +}
> +
> +static const struct component_ops lwmi_om_fan_method_component_ops = {
> + .bind = lwmi_om_fan_method_component_bind,
> + .unbind = lwmi_om_fan_method_component_unbind,
> +};
> +
> static int lwmi_other_probe(struct wmi_device *wdev, const void *context)
> {
> struct component_match *master_match = NULL;
> struct lwmi_om_priv *priv;
> + int ret;
>
> priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> if (!priv)
> @@ -1816,16 +1884,31 @@ static int lwmi_other_probe(struct wmi_device *wdev, const void *context)
> priv->wdev = wdev;
> dev_set_drvdata(&wdev->dev, priv);
>
> + ret = component_add(&wdev->dev, &lwmi_om_fan_method_component_ops);
> + if (ret)
> + return ret;
> +
> lwmi_cd_match_add_all(&wdev->dev, &master_match);
> - if (IS_ERR(master_match))
> - return PTR_ERR(master_match);
> + if (IS_ERR(master_match)) {
> + ret = PTR_ERR(master_match);
> + goto err_component;
> + }
> +
> + ret = component_master_add_with_match(&wdev->dev, &lwmi_om_master_ops,
> + master_match);
> + if (ret)
> + goto err_component;
> +
> + return 0;
>
> - return component_master_add_with_match(&wdev->dev, &lwmi_om_master_ops,
> - master_match);
> +err_component:
> + component_del(&wdev->dev, &lwmi_om_fan_method_component_ops);
> + return ret;
> }
>
> static void lwmi_other_remove(struct wmi_device *wdev)
> {
> + component_del(&wdev->dev, &lwmi_om_fan_method_component_ops);
> component_master_del(&wdev->dev, &lwmi_om_master_ops);
> }
>
^ permalink raw reply [flat|nested] 18+ messages in thread* Re: [RFC PATCH 3/3] platform/x86: lenovo: Add Legion Go Fan Method curve driver
2026-08-21 21:47 ` [RFC PATCH 3/3] platform/x86: lenovo: Add Legion Go Fan Method curve driver Aditya Dash
2026-08-22 18:47 ` Antheas Kapenekakis
2026-08-23 21:09 ` Rong Zhang
@ 2026-08-24 8:10 ` Ilpo Järvinen
2026-08-25 19:34 ` Derek John Clark
3 siblings, 0 replies; 18+ messages in thread
From: Ilpo Järvinen @ 2026-08-24 8:10 UTC (permalink / raw)
To: Aditya Dash
Cc: Derek J. Clark, Armin Wolf, Hans de Goede, Mark Pearson,
Guenter Roeck, Jonathan Corbet, Shuah Khan, linux-doc,
linux-hwmon, LKML, platform-driver-x86
On Sat, 22 Aug 2026, Aditya Dash wrote:
> Legion Go firmware keeps its custom fan curve in a separate Fan Method WMI
> interface. Method 5 returns ten control values and ten temperatures, while
> Method 6 replaces the complete table.
>
> The GUID also appears on Lenovo systems with a different table layout.
> Limit the driver to Legion Go 8APU1, Legion Go 8ASP2, Legion Go 8AHP2,
> Legion Go S 8ARP1, and Legion Go S 8APU1 products. These products use the
> same ten-point layout and Method 6 request.
>
> The curve applies to the same fan as the existing Other Mode attributes.
> Add a separate WMI driver and attach the ten automatic-point pairs to the
> HWMON device that Other Mode already provides. Match devices from the same
> WMI provider. Other Mode continues to work without Fan Method. Probe does
> not invoke either method.
>
> Validate both counts, every control value, and the complete temperature
> table before using a Method 5 reply. A point write holds the mutex while
> it reads the current table, changes one control value, and submits the
> complete Method 6 request. The other values remain unchanged.
>
> The HWMON mapping is not clear. On the tested Legion Go 8APU1, the fan
> responds to values from 0 through 115. This is Lenovo's 0 through 115
> percent range. Lenovo software shows 0 through 100 percent to the user,
> and 115 reaches the RPM observed in Full Speed mode. Firmware accepts
> values through 255, but values above 115 caused no observed RPM increase.
>
> This RFC exposes the firmware values unchanged. The fixed temperatures are
> read-only.
>
> Assisted-by: Pi:gpt-5.6-sol
> Signed-off-by: Aditya Dash <mradityadash@gmail.com>
> ---
> .../wmi/devices/lenovo-wmi-fan-method.rst | 34 ++
> .../wmi/devices/lenovo-wmi-other.rst | 3 +
> MAINTAINERS | 1 +
> drivers/platform/x86/lenovo/Kconfig | 11 +
> drivers/platform/x86/lenovo/Makefile | 1 +
> drivers/platform/x86/lenovo/wmi-fan-method.c | 380 ++++++++++++++++++
> drivers/platform/x86/lenovo/wmi-other.c | 97 ++++-
> 7 files changed, 520 insertions(+), 7 deletions(-)
> create mode 100644 Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> create mode 100644 drivers/platform/x86/lenovo/wmi-fan-method.c
>
> diff --git a/Documentation/wmi/devices/lenovo-wmi-fan-method.rst b/Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> new file mode 100644
> index 000000000000..67c9a92ed992
> --- /dev/null
> +++ b/Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> @@ -0,0 +1,34 @@
> +.. SPDX-License-Identifier: GPL-2.0-or-later
> +
> +==================================
> +Lenovo Fan Method WMI Driver
> +==================================
> +
> +WMI GUID ``92549549-4BDE-4F06-AC04-CE8BF898DBAA``
> +
> +The Lenovo Fan Method interface provides a ten-point firmware fan table on
> +Legion Go 8APU1, Legion Go 8ASP2, Legion Go 8AHP2, Legion Go S 8ARP1, and
> +Legion Go S 8APU1 products.
> +
> +The driver adds ``pwm1_auto_point1_*`` through
> +``pwm1_auto_point10_*`` to the HWMON device that the Lenovo Other Mode driver
> +owns. The temperature attributes are fixed and read-only. They contain points
> +from 10 through 100 degrees Celsius in 10-degree steps.
> +
> +Each ``pwm1_auto_point*_pwm`` attribute is read-write and passes a firmware
> +control value from 0 through 255 without scaling. On the tested Legion Go
> +8APU1, the hardware responds from 0 through 115, corresponding to Lenovo's
> +0 through 115 percent range. Lenovo software shows 0 through 100 percent to
> +the user, and 115 percent reaches the RPM observed in Full Speed mode. The
> +firmware accepts values through 255, but values above 115 caused no observed
> +RPM increase.
> +
> +A control-value read validates both ten-entry tables before returning data. A
> +point write reads the current table, changes one control value, and submits the
> +complete request. It preserves the other nine control values and all returned
> +temperatures.
> +
> +The Fan Method and Other Mode drivers use separate modules and WMI devices.
> +The component framework associates devices that belong to the same WMI
> +provider. Fan Method curve attributes are absent when either interface is not
> +available.
> diff --git a/Documentation/wmi/devices/lenovo-wmi-other.rst b/Documentation/wmi/devices/lenovo-wmi-other.rst
> index c93e9e6f3fd0..34352dbd6fb9 100644
> --- a/Documentation/wmi/devices/lenovo-wmi-other.rst
> +++ b/Documentation/wmi/devices/lenovo-wmi-other.rst
> @@ -60,6 +60,9 @@ Some Legion Go firmware does not advertise fan 1 RPM through Capability
> Data. In that case, the driver reads Other Mode feature ``0x04030001`` for
> ``fan1_input``. Value ``0xffffffff`` means that RPM is unavailable.
>
> +When the separate Lenovo Fan Method driver binds to the same WMI provider, it
> +adds ten automatic fan-curve points to this HWMON device.
> +
> LENOVO_CAPABILITY_DATA_01
> -------------------------
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3820b286f09f..8612c2323540 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14689,6 +14689,7 @@ M: Mark Pearson <mpearson-lenovo@squebb.ca>
> M: Derek J. Clark <derekjohn.clark@gmail.com>
> L: platform-driver-x86@vger.kernel.org
> S: Maintained
> +F: Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> F: Documentation/wmi/devices/lenovo-wmi-gamezone.rst
> F: Documentation/wmi/devices/lenovo-wmi-other.rst
> F: drivers/platform/x86/lenovo/*
> diff --git a/drivers/platform/x86/lenovo/Kconfig b/drivers/platform/x86/lenovo/Kconfig
> index 4443f40ef8aa..e69942ce3093 100644
> --- a/drivers/platform/x86/lenovo/Kconfig
> +++ b/drivers/platform/x86/lenovo/Kconfig
> @@ -276,3 +276,14 @@ config LENOVO_WMI_TUNING
>
> To compile this driver as a module, choose M here: the module will
> be called lenovo-wmi-other.
> +
> +config LENOVO_WMI_FAN_METHOD
> + tristate "Lenovo Fan Method WMI Driver"
> + depends on DMI
> + depends on LENOVO_WMI_TUNING
> + help
> + Say Y here to add the firmware fan table on supported Lenovo
> + Legion Go products to the Lenovo Other Mode HWMON device.
> +
> + To compile this driver as a module, choose M here: the module will
> + be called lenovo-wmi-fan-method.
> diff --git a/drivers/platform/x86/lenovo/Makefile b/drivers/platform/x86/lenovo/Makefile
> index 91a9370f11b3..171a19e01479 100644
> --- a/drivers/platform/x86/lenovo/Makefile
> +++ b/drivers/platform/x86/lenovo/Makefile
> @@ -17,6 +17,7 @@ lenovo-target-$(CONFIG_LENOVO_WMI_EVENTS) += wmi-events.o
> lenovo-target-$(CONFIG_LENOVO_WMI_HELPERS) += wmi-helpers.o
> lenovo-target-$(CONFIG_LENOVO_WMI_GAMEZONE) += wmi-gamezone.o
> lenovo-target-$(CONFIG_LENOVO_WMI_TUNING) += wmi-other.o
> +lenovo-target-$(CONFIG_LENOVO_WMI_FAN_METHOD) += wmi-fan-method.o
>
> # Add 'lenovo' prefix to each module listed in lenovo-target-*
> define LENOVO_OBJ_TARGET
> diff --git a/drivers/platform/x86/lenovo/wmi-fan-method.c b/drivers/platform/x86/lenovo/wmi-fan-method.c
> new file mode 100644
> index 000000000000..4f29c4134caf
> --- /dev/null
> +++ b/drivers/platform/x86/lenovo/wmi-fan-method.c
> @@ -0,0 +1,380 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Lenovo Fan Method WMI interface driver.
> + *
> + * This driver exposes the firmware fan table through HWMON automatic-point
> + * attributes on selected Lenovo Legion Go products.
> + */
> +
> +#include <linux/cleanup.h>
> +#include <linux/component.h>
> +#include <linux/device.h>
> +#include <linux/dmi.h>
> +#include <linux/err.h>
> +#include <linux/kernel.h>
> +#include <linux/limits.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/sysfs.h>
> +#include <linux/types.h>
> +#include <linux/unaligned.h>
> +#include <linux/wmi.h>
> +
> +#define LENOVO_FAN_METHOD_GUID "92549549-4BDE-4F06-AC04-CE8BF898DBAA"
> +
> +#define LENOVO_FAN_METHOD_GET_CURVE 5
> +#define LENOVO_FAN_METHOD_SET_CURVE 6
> +#define LENOVO_FAN_CURVE_POINTS 10
> +#define LENOVO_FAN_CURVE_REPLY_SIZE 88
> +#define LENOVO_FAN_CURVE_WRITE_SIZE 64
> +
> +#define LENOVO_FAN_REPLY_SPEED_COUNT_OFFSET 0
> +#define LENOVO_FAN_REPLY_SPEED_OFFSET 4
> +#define LENOVO_FAN_REPLY_TEMP_COUNT_OFFSET 44
> +#define LENOVO_FAN_REPLY_TEMP_OFFSET 48
> +
> +#define LENOVO_FAN_WRITE_SPEED_COUNT_OFFSET 2
> +#define LENOVO_FAN_WRITE_SPEED_OFFSET 6
> +#define LENOVO_FAN_WRITE_TEMP_TYPE_OFFSET 26
> +#define LENOVO_FAN_WRITE_TEMP_COUNT_OFFSET 27
> +#define LENOVO_FAN_WRITE_TEMP_OFFSET 31
> +#define LENOVO_FAN_WRITE_TRAILER_OFFSET 51
> +#define LENOVO_FAN_WRITE_TRAILER_VALUE_OFFSET 53
> +
> +#define LENOVO_FAN_WRITE_TEMP_TYPE 1
> +#define LENOVO_FAN_WRITE_TRAILER 0x5a
> +#define LENOVO_FAN_WRITE_TRAILER_VALUE 100
> +
> +static const struct dmi_system_id lwmi_fan_dmi_table[] = {
> + {
> + .ident = "Lenovo Legion Go 8APU1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8APU1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go S 8APU1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go S 8APU1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go S 8ARP1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go S 8ARP1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go 8ASP2",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8ASP2"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go 8AHP2",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8AHP2"),
> + },
> + },
> + {}
> +};
> +
> +static const u16 lwmi_fan_temperatures[LENOVO_FAN_CURVE_POINTS] = {
> + 10, 20, 30, 40, 50, 60, 70, 80, 90, 100
> +};
> +
> +struct lwmi_fan_method_curve {
> + u16 speed[LENOVO_FAN_CURVE_POINTS];
> + u16 temperature[LENOVO_FAN_CURVE_POINTS];
> +};
> +
> +struct lwmi_fan_method_priv;
> +
> +struct lwmi_fan_method_attr {
> + struct device_attribute dev_attr;
> + struct lwmi_fan_method_priv *priv;
> + u8 index;
> +};
> +
> +struct lwmi_fan_method_priv {
> + struct wmi_device *wdev;
> + struct mutex lock; /* Serializes all Fan Method calls. */
Please move the comment a bit right to separate code from comment
visually (by 1 tab or so is enough as long as there's > 1 whitespace).
> + struct lwmi_fan_method_attr point_attrs[LENOVO_FAN_CURVE_POINTS * 2];
> + struct attribute *attrs[LENOVO_FAN_CURVE_POINTS * 2 + 1];
> + struct attribute_group group;
> +};
> +
> +static int lwmi_fan_method_get_curve(struct lwmi_fan_method_priv *priv,
> + struct lwmi_fan_method_curve *curve)
> +{
> + u8 input[] = { 1, 1 };
> + struct wmi_buffer in = {
> + .length = sizeof(input),
> + .data = input,
> + };
> + struct wmi_buffer out = {};
> + const u8 *buffer;
> + int ret, i;
> +
> + ret = wmidev_invoke_method(priv->wdev, 0,
> + LENOVO_FAN_METHOD_GET_CURVE, &in, &out,
> + LENOVO_FAN_CURVE_REPLY_SIZE);
> + if (ret)
> + return ret;
> +
> + buffer = out.data;
Best practices with this interface: Declare variable on this lines
(mid-function) and use __free().
> + if (get_unaligned_le32(buffer + LENOVO_FAN_REPLY_SPEED_COUNT_OFFSET) !=
> + LENOVO_FAN_CURVE_POINTS ||
> + get_unaligned_le32(buffer + LENOVO_FAN_REPLY_TEMP_COUNT_OFFSET) !=
Please read what wmidev_invoke_method()'s function comment says about
alignment.
> + LENOVO_FAN_CURVE_POINTS) {
> + ret = -ERANGE;
> + goto out_free;
> + }
> +
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++) {
> + u32 speed = get_unaligned_le32(buffer + LENOVO_FAN_REPLY_SPEED_OFFSET +
> + i * sizeof(u32));
> + u32 temperature =
> + get_unaligned_le32(buffer + LENOVO_FAN_REPLY_TEMP_OFFSET +
> + i * sizeof(u32));
> +
> + if (speed > U8_MAX || temperature != lwmi_fan_temperatures[i]) {
> + ret = -ERANGE;
> + goto out_free;
> + }
> +
> + curve->speed[i] = speed;
> + curve->temperature[i] = temperature;
> + }
> +
> +out_free:
> + kfree(out.data);
> + return ret;
> +}
> +
> +static int lwmi_fan_method_set_curve(struct lwmi_fan_method_priv *priv,
> + const struct lwmi_fan_method_curve *curve)
> +{
> + u8 buffer[LENOVO_FAN_CURVE_WRITE_SIZE] = { 0xff, 0x01 };
> + struct wmi_buffer in = {
> + .length = sizeof(buffer),
> + .data = buffer,
> + };
> + int i;
> +
> + put_unaligned_le32(LENOVO_FAN_CURVE_POINTS,
> + buffer + LENOVO_FAN_WRITE_SPEED_COUNT_OFFSET);
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++)
> + put_unaligned_le16(curve->speed[i],
> + buffer + LENOVO_FAN_WRITE_SPEED_OFFSET +
> + i * sizeof(u16));
> +
> + buffer[LENOVO_FAN_WRITE_TEMP_TYPE_OFFSET] = LENOVO_FAN_WRITE_TEMP_TYPE;
> + put_unaligned_le32(LENOVO_FAN_CURVE_POINTS,
> + buffer + LENOVO_FAN_WRITE_TEMP_COUNT_OFFSET);
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++)
> + put_unaligned_le16(curve->temperature[i],
> + buffer + LENOVO_FAN_WRITE_TEMP_OFFSET +
> + i * sizeof(u16));
> +
> + buffer[LENOVO_FAN_WRITE_TRAILER_OFFSET] = LENOVO_FAN_WRITE_TRAILER;
> + put_unaligned_le16(LENOVO_FAN_WRITE_TRAILER_VALUE,
> + buffer + LENOVO_FAN_WRITE_TRAILER_VALUE_OFFSET);
> +
> + return wmidev_invoke_procedure(priv->wdev, 0,
> + LENOVO_FAN_METHOD_SET_CURVE, &in);
> +}
> +
> +static ssize_t lwmi_fan_method_pwm_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> + struct lwmi_fan_method_priv *priv = point_attr->priv;
> + struct lwmi_fan_method_curve curve;
> + int ret;
> +
> + guard(mutex)(&priv->lock);
> +
> + ret = lwmi_fan_method_get_curve(priv, &curve);
> + if (ret)
> + return ret;
> +
> + return sysfs_emit(buf, "%u\n", curve.speed[point_attr->index]);
> +}
> +
> +static ssize_t lwmi_fan_method_pwm_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> + struct lwmi_fan_method_priv *priv = point_attr->priv;
> + struct lwmi_fan_method_curve curve;
> + unsigned long pwm;
> + int ret;
> +
> + ret = kstrtoul(buf, 10, &pwm);
> + if (ret)
> + return ret;
> + if (pwm > U8_MAX)
Use kstrtou8() ?
> + return -EINVAL;
> +
> + guard(mutex)(&priv->lock);
> +
> + ret = lwmi_fan_method_get_curve(priv, &curve);
> + if (ret)
> + return ret;
> +
> + curve.speed[point_attr->index] = pwm;
> + ret = lwmi_fan_method_set_curve(priv, &curve);
> +
> + return ret ? ret : count;
> +}
> +
> +static ssize_t lwmi_fan_method_temp_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> +
> + return sysfs_emit(buf, "%u\n",
> + lwmi_fan_temperatures[point_attr->index] * 1000);
Check if that 1000 can be replaced with something from units.h.
> +}
> +
> +#define LWMI_FAN_METHOD_POINT_NAMES(_point) \
> + "pwm1_auto_point" #_point "_pwm", \
> + "pwm1_auto_point" #_point "_temp"
> +
> +static const char * const lwmi_fan_method_attr_names[] = {
> + LWMI_FAN_METHOD_POINT_NAMES(1),
> + LWMI_FAN_METHOD_POINT_NAMES(2),
> + LWMI_FAN_METHOD_POINT_NAMES(3),
> + LWMI_FAN_METHOD_POINT_NAMES(4),
> + LWMI_FAN_METHOD_POINT_NAMES(5),
> + LWMI_FAN_METHOD_POINT_NAMES(6),
> + LWMI_FAN_METHOD_POINT_NAMES(7),
> + LWMI_FAN_METHOD_POINT_NAMES(8),
> + LWMI_FAN_METHOD_POINT_NAMES(9),
> + LWMI_FAN_METHOD_POINT_NAMES(10),
> +};
> +
> +#undef LWMI_FAN_METHOD_POINT_NAMES
> +
> +static void lwmi_fan_method_attrs_init(struct lwmi_fan_method_priv *priv)
> +{
> + int i;
> +
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++) {
> + struct lwmi_fan_method_attr *pwm = &priv->point_attrs[i * 2];
> + struct lwmi_fan_method_attr *temp = &priv->point_attrs[i * 2 + 1];
> +
> + sysfs_attr_init(&pwm->dev_attr.attr);
> + pwm->dev_attr.attr.name = lwmi_fan_method_attr_names[i * 2];
> + pwm->dev_attr.attr.mode = 0644;
> + pwm->dev_attr.show = lwmi_fan_method_pwm_show;
> + pwm->dev_attr.store = lwmi_fan_method_pwm_store;
> + pwm->priv = priv;
> + pwm->index = i;
> + priv->attrs[i * 2] = &pwm->dev_attr.attr;
> +
> + sysfs_attr_init(&temp->dev_attr.attr);
> + temp->dev_attr.attr.name = lwmi_fan_method_attr_names[i * 2 + 1];
> + temp->dev_attr.attr.mode = 0444;
> + temp->dev_attr.show = lwmi_fan_method_temp_show;
> + temp->index = i;
> + priv->attrs[i * 2 + 1] = &temp->dev_attr.attr;
> + }
> +
> + priv->group.attrs = priv->attrs;
> +}
> +
> +static int lwmi_fan_method_master_bind(struct device *dev)
> +{
> + struct lwmi_fan_method_priv *priv = dev_get_drvdata(dev);
> +
> + return component_bind_all(dev, &priv->group);
> +}
> +
> +static void lwmi_fan_method_master_unbind(struct device *dev)
> +{
> + component_unbind_all(dev, NULL);
> +}
> +
> +static const struct component_master_ops lwmi_fan_method_master_ops = {
> + .bind = lwmi_fan_method_master_bind,
> + .unbind = lwmi_fan_method_master_unbind,
> +};
> +
> +static int lwmi_fan_method_component_compare(struct device *dev, void *data)
> +{
> + struct device *master = data;
> +
> + return dev->driver &&
> + !strcmp(dev->driver->name, "lenovo_wmi_other") &&
> + dev->parent == master->parent;
> +}
> +
> +static int lwmi_fan_method_probe(struct wmi_device *wdev, const void *context)
> +{
> + struct component_match *master_match = NULL;
> + struct lwmi_fan_method_priv *priv;
> +
> + if (!dmi_check_system(lwmi_fan_dmi_table))
> + return -ENODEV;
> +
> + priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->wdev = wdev;
> + mutex_init(&priv->lock);
This would need to be paired with mutex_destroy.
BUT instead, use devm_mutex_init() + don't forget error handling, it can
fail.
> + lwmi_fan_method_attrs_init(priv);
> + dev_set_drvdata(&wdev->dev, priv);
> +
> + component_match_add(&wdev->dev, &master_match,
> + lwmi_fan_method_component_compare, &wdev->dev);
> + if (IS_ERR(master_match))
> + return PTR_ERR(master_match);
> +
> + return component_master_add_with_match(&wdev->dev,
> + &lwmi_fan_method_master_ops,
> + master_match);
> +}
> +
> +static void lwmi_fan_method_remove(struct wmi_device *wdev)
> +{
> + component_master_del(&wdev->dev, &lwmi_fan_method_master_ops);
> +}
> +
> +static const struct wmi_device_id lwmi_fan_method_id_table[] = {
> + { LENOVO_FAN_METHOD_GUID, NULL },
> + {}
> +};
> +
> +static struct wmi_driver lwmi_fan_method_driver = {
> + .driver = {
> + .name = "lenovo_wmi_fan_method",
> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> + },
> + .id_table = lwmi_fan_method_id_table,
> + .probe = lwmi_fan_method_probe,
> + .remove = lwmi_fan_method_remove,
> + .no_singleton = true,
> +};
> +
> +MODULE_DEVICE_TABLE(wmi, lwmi_fan_method_id_table);
> +module_wmi_driver(lwmi_fan_method_driver);
> +
> +MODULE_AUTHOR("Aditya Dash <mradityadash@gmail.com>");
> +MODULE_DESCRIPTION("Lenovo Fan Method WMI Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
> index b4be7739b243..72d3510b17b2 100644
> --- a/drivers/platform/x86/lenovo/wmi-other.c
> +++ b/drivers/platform/x86/lenovo/wmi-other.c
> @@ -192,11 +192,13 @@ struct lwmi_om_priv {
> struct device *fw_attr_dev;
> struct kset *fw_attr_kset;
> struct wmi_device *wdev;
> + const struct attribute_group *fan_method_group;
> int ida_id;
>
> struct lwmi_fan_info fan_info[LWMI_FAN_NR];
> bool fullspeed_supported;
> bool fan0_input_fallback;
> + bool fan_method_group_added;
>
> struct {
> bool capdata00_collected : 1;
> @@ -542,6 +544,31 @@ static const struct hwmon_chip_info lwmi_om_hwmon_chip_info = {
> .info = lwmi_om_hwmon_info,
> };
>
> +static int lwmi_om_fan_method_group_add(struct lwmi_om_priv *priv)
> +{
> + int ret;
> +
> + if (!priv->hwmon_dev || !priv->fan_method_group ||
> + priv->fan_method_group_added)
> + return 0;
> +
> + ret = sysfs_create_group(&priv->hwmon_dev->kobj,
> + priv->fan_method_group);
> + if (!ret)
> + priv->fan_method_group_added = true;
> +
> + return ret;
> +}
> +
> +static void lwmi_om_fan_method_group_remove(struct lwmi_om_priv *priv)
> +{
> + if (!priv->hwmon_dev || !priv->fan_method_group_added)
> + return;
> +
> + sysfs_remove_group(&priv->hwmon_dev->kobj, priv->fan_method_group);
> + priv->fan_method_group_added = false;
> +}
> +
> /**
> * lwmi_om_hwmon_add() - Register HWMON device if all info is collected
> * @priv: Driver private data
> @@ -550,9 +577,9 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> {
> u32 rpm;
> long enable;
> - int i, valid;
> + int i, ret, valid;
>
> - if (WARN_ON(priv->hwmon_dev))
> + if (priv->hwmon_dev)
If you need changes to hwmon_dev behavior, could you please separate
things related to that into own patch with a proper justification (you can
refer to the following change with "an upcoming change" if needed to
explain why you have to do it).
> return;
>
> if (!priv->fan_flags.capdata00_collected || !priv->fan_flags.capdata_fan_collected) {
> @@ -592,7 +619,8 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> }
> }
>
> - if (valid == 0 && !priv->fullspeed_supported && !priv->fan0_input_fallback) {
> + if (valid == 0 && !priv->fullspeed_supported &&
> + !priv->fan0_input_fallback && !priv->fan_method_group) {
> dev_warn(&priv->wdev->dev,
> "fan reporting/tuning is unsupported on this device\n");
> return;
> @@ -609,6 +637,11 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> return;
> }
>
> + ret = lwmi_om_fan_method_group_add(priv);
> + if (ret)
> + dev_warn(&priv->wdev->dev,
> + "failed to register Fan Method attributes: %d\n", ret);
> +
> dev_dbg(&priv->wdev->dev, "registered HWMON device\n");
> }
>
> @@ -623,6 +656,7 @@ static void lwmi_om_hwmon_remove(struct lwmi_om_priv *priv)
> if (!priv->hwmon_dev)
> return;
>
> + lwmi_om_fan_method_group_remove(priv);
> hwmon_device_unregister(priv->hwmon_dev);
> priv->hwmon_dev = NULL;
> }
> @@ -1801,10 +1835,44 @@ static const struct component_master_ops lwmi_om_master_ops = {
> .unbind = lwmi_om_master_unbind,
> };
>
> +static int lwmi_om_fan_method_component_bind(struct device *component,
> + struct device *master, void *data)
> +{
> + const struct attribute_group *group = data;
> + struct lwmi_om_priv *priv = dev_get_drvdata(component);
> + int ret;
> +
> + if (!group)
> + return -EINVAL;
> +
> + priv->fan_method_group = group;
> + lwmi_om_hwmon_add(priv);
> + ret = lwmi_om_fan_method_group_add(priv);
> + if (ret)
> + priv->fan_method_group = NULL;
> +
> + return ret;
> +}
> +
> +static void lwmi_om_fan_method_component_unbind(struct device *component,
> + struct device *master, void *data)
> +{
> + struct lwmi_om_priv *priv = dev_get_drvdata(component);
> +
> + lwmi_om_fan_method_group_remove(priv);
> + priv->fan_method_group = NULL;
> +}
> +
> +static const struct component_ops lwmi_om_fan_method_component_ops = {
> + .bind = lwmi_om_fan_method_component_bind,
> + .unbind = lwmi_om_fan_method_component_unbind,
> +};
> +
> static int lwmi_other_probe(struct wmi_device *wdev, const void *context)
> {
> struct component_match *master_match = NULL;
> struct lwmi_om_priv *priv;
> + int ret;
>
> priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> if (!priv)
> @@ -1816,16 +1884,31 @@ static int lwmi_other_probe(struct wmi_device *wdev, const void *context)
> priv->wdev = wdev;
> dev_set_drvdata(&wdev->dev, priv);
>
> + ret = component_add(&wdev->dev, &lwmi_om_fan_method_component_ops);
> + if (ret)
> + return ret;
> +
> lwmi_cd_match_add_all(&wdev->dev, &master_match);
> - if (IS_ERR(master_match))
> - return PTR_ERR(master_match);
> + if (IS_ERR(master_match)) {
> + ret = PTR_ERR(master_match);
> + goto err_component;
> + }
> +
> + ret = component_master_add_with_match(&wdev->dev, &lwmi_om_master_ops,
> + master_match);
> + if (ret)
> + goto err_component;
> +
> + return 0;
>
> - return component_master_add_with_match(&wdev->dev, &lwmi_om_master_ops,
> - master_match);
> +err_component:
> + component_del(&wdev->dev, &lwmi_om_fan_method_component_ops);
> + return ret;
> }
>
> static void lwmi_other_remove(struct wmi_device *wdev)
> {
> + component_del(&wdev->dev, &lwmi_om_fan_method_component_ops);
> component_master_del(&wdev->dev, &lwmi_om_master_ops);
> }
>
>
--
i.
^ permalink raw reply [flat|nested] 18+ messages in thread* Re: [RFC PATCH 3/3] platform/x86: lenovo: Add Legion Go Fan Method curve driver
2026-08-21 21:47 ` [RFC PATCH 3/3] platform/x86: lenovo: Add Legion Go Fan Method curve driver Aditya Dash
` (2 preceding siblings ...)
2026-08-24 8:10 ` Ilpo Järvinen
@ 2026-08-25 19:34 ` Derek John Clark
3 siblings, 0 replies; 18+ messages in thread
From: Derek John Clark @ 2026-08-25 19:34 UTC (permalink / raw)
To: Aditya Dash
Cc: Ilpo Järvinen, Armin Wolf, Hans de Goede, Mark Pearson,
Guenter Roeck, Jonathan Corbet, Shuah Khan, linux-doc,
linux-hwmon, linux-kernel, platform-driver-x86
On Fri, Aug 21, 2026 at 2:47 PM Aditya Dash <mradityadash@gmail.com> wrote:
>
Hi Aditya,
Thank you for taking on this task. It has been on my to-do list for
far too long and is a much requested feature. I took the liberty of
reviewing the documentation provided from Lenovo and have some
insights that will need some testing.
> Legion Go firmware keeps its custom fan curve in a separate Fan Method WMI
> interface. Method 5 returns ten control values and ten temperatures, while
> Method 6 replaces the complete table.
According to the documentation, these methods should be available in
the "Legacy" LENOVO_FAN_MENTHOD GUID you've implemented here and the
newer LENOVO_OTHER_METHOD GUID:
Class LENOVO_FAN_METHOD
GUID guid("{92549549-4bde-4f06-ac04-ce8bf898dbaa}")
Class LENOVO_OTHER_METHOD （GetFeatureValue/ SetFeatureValue）
GUID guid("{dc2a8805-3a8c-41ba-a6f7-092e0089cd3b}")
Given that, It might be more prudent to implement this directly into
lenovo-wmi-other and add the older GUID. They appear to be 1:1
compatible regardless of which GUID you use. We'll need to ensure the
methods not implemented by the fan method GUID are gated adequately if
we go that route. Alternatively, we should be able to instantiate
another driver on the other method GUID similtaniously. That would
still require some cross driver notifiers, but either option would
prevent needing duplicate code in two places for devices that
implement one vs the other. I'd be interested to hear Armin/Ilpo's
thoughts on this as well before we decide on a direction there.
> The GUID also appears on Lenovo systems with a different table layout.
> Limit the driver to Legion Go 8APU1, Legion Go 8ASP2, Legion Go 8AHP2,
> Legion Go S 8ARP1, and Legion Go S 8APU1 products. These products use the
> same ten-point layout and Method 6 request.
We should attempt to ensure the interface works universally.
Here is the BMOF data for the interface:
[WMI, Dynamic, Provider("WmiProv"), Locale("MS\\0x409"),
Description("LENOVO_FAN_METHOD class"),
guid("{92549549-4bde-4f06-ac04-ce8bf898dbaa}")]
class LENOVO_FAN_METHOD {
[key, read] string InstanceName;
[read] boolean Active;
[WmiMethodId(5), Implemented, Description("Get Fan Table ")] void
Fan_Get_Table([in] uint8 FanID, [in] uint8 SensorID, [out] uint32
FanTableSize, [out, WmiSizeIs("FanTableSize")] uint32 FanTable[],
[out] uint32 SensorTableSize, [out, WmiSizeIs("SensorTableSize")]
uint32 SensorTable[]);
[WmiMethodId(6), Implemented, Description("Set Fan Table ")] void
Fan_Set_Table([in, Max(64)] uint8 FanTable[]);
};
As you can see, the FanTableSize u32 and SensorTableSize u32's provide
the length of both the temperature and fan speed set points. The Go
series happens to be 10, but we should query this on probe and
dynamically add the number of pwm1_auto_point_pwm/temp attributes
needed. They can be instantiated with an index, so recalling a
specific arbitrary attribute shouldn't be a challenge for reporting
the current value or changing a specific value. To do that, we'll need
to switch to using devm_hwmon_device_register_with_info()
That would allow dropping the DMI table entirely while adding support
for a lot more hardware.
> The curve applies to the same fan as the existing Other Mode attributes.
> Add a separate WMI driver and attach the ten automatic-point pairs to the
> HWMON device that Other Mode already provides. Match devices from the same
> WMI provider. Other Mode continues to work without Fan Method. Probe does
> not invoke either method.
>
> Validate both counts, every control value, and the complete temperature
> table before using a Method 5 reply. A point write holds the mutex while
> it reads the current table, changes one control value, and submits the
> complete Method 6 request. The other values remain unchanged.
>
> The HWMON mapping is not clear. On the tested Legion Go 8APU1, the fan
> responds to values from 0 through 115. This is Lenovo's 0 through 115
> percent range. Lenovo software shows 0 through 100 percent to the user,
> and 115 reaches the RPM observed in Full Speed mode. Firmware accepts
> values through 255, but values above 115 caused no observed RPM increase.
As others have stated, we should scale these inputs from 0-255 for all
hwmon character files. That being said, I'm on the fence about the
115% concept. There is nothing in the docs that desribes these limits
or a way to probe the max for a specific device, so I'm inclined to
treat anything above 100 as invalid.
> This RFC exposes the firmware values unchanged. The fixed temperatures are
> read-only.
Is there a reason for this? The temp table shold be editable to an
extent. Given that the hardware will reject unsupported values, it
seems as though we could store the old value and re-query after
setting to determine inf -EINVAL conditions were met.
One other thing to consider is this usage note from the docs. Note
that Custom Mode below refers to the GUID for hte methods, not the
custom profile:
5.4 Custom Mode Fan Table Rule:
In custom mode, the user adjusts the power limit, and the fan table
should be adjusted accordingly according to the total power limit. If
the value of the fan table set by the user is lower than the reference
value of the fan table corresponding to the power limit at that time,
the value of the fan table of this order will be automatically
replaced.
C - Current Total Power Consumption set by user
Q - Quiet Mode Total Power Consumption
B - Balance Mode Total Power Consumption
P - Performance Mode Total Power Consumption
C<= Q
The value of Fan table cannot be lower than the value of Quiet Mode
Fan Table in Custom Mode
Q< C <= B
The value of Fan table cannot be lower than the value of Balance Mode
Fan Table in Custom Mode
B<C<= P
The value of Fan table cannot be lower than the value of Performance
Mode Fan Table in Custom Mode
P<C
The value of Fan table cannot be lower than the value of Performance
Mode Fan Table in Custom Mode +
Last order greater than 50db (52db, 54db or 55db) in Custom Mode
One other piece of the puzzle to consider as well. There is a
LENOVO_FAN_TABLE_DATA data block:
[WMI, Dynamic, Provider("WmiProv"), Locale("MS\\0x409"),
Description("Definition of Fan Table list"),
guid("{87fb2a6d-d802-48e7-9208-4576c5f5c8d8}")]
class LENOVO_FAN_TABLE_DATA {
[key, read] string InstanceName;
[read] boolean Active;
[WmiDataId(1), read, Description("Mode.")] uint16 Mode;
[WmiDataId(2), read, Description("Fan ID.")] uint16 Fan_Id;
[WmiDataId(3), read, Description("Fan Table Len.")] uint32 FanTable_Len;
[WmiDataId(4), read, Description("Fan Table Data."),
WmiSizeIs("FanTable_Len")] uint16 FanTable_Data[];
[WmiDataId(5), read, Description("Sensor ID.")] uint32 Sensor_ID;
[WmiDataId(6), read, Description("Sensor Table Len.")] uint32 SensorTable_Len;
[WmiDataId(7), read, Description("Sensor Table Data."),
WmiSizeIs("SensorTable_Len")] uint16 SensorTable_Data[];
[WmiDataId(8), read, Description("Start Upwards Adjust Number.")]
uint8 StartOnlyUpwardAdjustNumber;
[WmiDataId(9), read, Description("End Upwards Adjust Number.")]
uint8 EndOnlyUpwardAdjustNumber;
[WmiDataId(10), read, Description("Current Fan Max Speed.")] uint16
CurrentFanMaxSpeed;
[WmiDataId(11), read, Description("Start Downwards Adjust Number")]
uint8 DesignMaxFanSpeedNumber;
[WmiDataId(12), read, Description("End Downwards Adjust Number")]
uint8 Reserved;
[WmiDataId(13), read, Description("Current Fan Min Speed.")] uint16
CurrentFanMinSpeed;
[WmiDataId(14), read, Description("Fan Speed Step.")] uint16 FanSpeedStep;
[WmiDataId(15), read, Description("Max Sensor Temperature.")] uint16
MaxSensorTemperature;
[WmiDataId(16), read, Description("Min Sensor Temperature.")] uint16
MinSensorTemperature;
[WmiDataId(17), read, Description("Max Sensor Temperature.")] uint16
SensorTemperatureStep;
};
I only checked on the Go 2, that device has an empty data table for
all 15 instances and the method is stubbed in DSDT, but there is
likely some laptops out there that populate this data. It should work
similarly to the existing capdata/fan test data interfaces so it may
be worth considering getting hardware limits from that, if available,
and only doing the re-query when reliable data isn't available.
I'll hold off on reviewing the rest of the substance of the driver
until you've had a chance to adjust based on feedback. Most of what I
would have brought up was covered by others already.
Thanks,
Derek
> Assisted-by: Pi:gpt-5.6-sol
> Signed-off-by: Aditya Dash <mradityadash@gmail.com>
> ---
> .../wmi/devices/lenovo-wmi-fan-method.rst | 34 ++
> .../wmi/devices/lenovo-wmi-other.rst | 3 +
> MAINTAINERS | 1 +
> drivers/platform/x86/lenovo/Kconfig | 11 +
> drivers/platform/x86/lenovo/Makefile | 1 +
> drivers/platform/x86/lenovo/wmi-fan-method.c | 380 ++++++++++++++++++
> drivers/platform/x86/lenovo/wmi-other.c | 97 ++++-
> 7 files changed, 520 insertions(+), 7 deletions(-)
> create mode 100644 Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> create mode 100644 drivers/platform/x86/lenovo/wmi-fan-method.c
>
> diff --git a/Documentation/wmi/devices/lenovo-wmi-fan-method.rst b/Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> new file mode 100644
> index 000000000000..67c9a92ed992
> --- /dev/null
> +++ b/Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> @@ -0,0 +1,34 @@
> +.. SPDX-License-Identifier: GPL-2.0-or-later
> +
> +==================================
> +Lenovo Fan Method WMI Driver
> +==================================
> +
> +WMI GUID ``92549549-4BDE-4F06-AC04-CE8BF898DBAA``
> +
> +The Lenovo Fan Method interface provides a ten-point firmware fan table on
> +Legion Go 8APU1, Legion Go 8ASP2, Legion Go 8AHP2, Legion Go S 8ARP1, and
> +Legion Go S 8APU1 products.
> +
> +The driver adds ``pwm1_auto_point1_*`` through
> +``pwm1_auto_point10_*`` to the HWMON device that the Lenovo Other Mode driver
> +owns. The temperature attributes are fixed and read-only. They contain points
> +from 10 through 100 degrees Celsius in 10-degree steps.
> +
> +Each ``pwm1_auto_point*_pwm`` attribute is read-write and passes a firmware
> +control value from 0 through 255 without scaling. On the tested Legion Go
> +8APU1, the hardware responds from 0 through 115, corresponding to Lenovo's
> +0 through 115 percent range. Lenovo software shows 0 through 100 percent to
> +the user, and 115 percent reaches the RPM observed in Full Speed mode. The
> +firmware accepts values through 255, but values above 115 caused no observed
> +RPM increase.
> +
> +A control-value read validates both ten-entry tables before returning data. A
> +point write reads the current table, changes one control value, and submits the
> +complete request. It preserves the other nine control values and all returned
> +temperatures.
> +
> +The Fan Method and Other Mode drivers use separate modules and WMI devices.
> +The component framework associates devices that belong to the same WMI
> +provider. Fan Method curve attributes are absent when either interface is not
> +available.
> diff --git a/Documentation/wmi/devices/lenovo-wmi-other.rst b/Documentation/wmi/devices/lenovo-wmi-other.rst
> index c93e9e6f3fd0..34352dbd6fb9 100644
> --- a/Documentation/wmi/devices/lenovo-wmi-other.rst
> +++ b/Documentation/wmi/devices/lenovo-wmi-other.rst
> @@ -60,6 +60,9 @@ Some Legion Go firmware does not advertise fan 1 RPM through Capability
> Data. In that case, the driver reads Other Mode feature ``0x04030001`` for
> ``fan1_input``. Value ``0xffffffff`` means that RPM is unavailable.
>
> +When the separate Lenovo Fan Method driver binds to the same WMI provider, it
> +adds ten automatic fan-curve points to this HWMON device.
> +
> LENOVO_CAPABILITY_DATA_01
> -------------------------
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3820b286f09f..8612c2323540 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -14689,6 +14689,7 @@ M: Mark Pearson <mpearson-lenovo@squebb.ca>
> M: Derek J. Clark <derekjohn.clark@gmail.com>
> L: platform-driver-x86@vger.kernel.org
> S: Maintained
> +F: Documentation/wmi/devices/lenovo-wmi-fan-method.rst
> F: Documentation/wmi/devices/lenovo-wmi-gamezone.rst
> F: Documentation/wmi/devices/lenovo-wmi-other.rst
> F: drivers/platform/x86/lenovo/*
> diff --git a/drivers/platform/x86/lenovo/Kconfig b/drivers/platform/x86/lenovo/Kconfig
> index 4443f40ef8aa..e69942ce3093 100644
> --- a/drivers/platform/x86/lenovo/Kconfig
> +++ b/drivers/platform/x86/lenovo/Kconfig
> @@ -276,3 +276,14 @@ config LENOVO_WMI_TUNING
>
> To compile this driver as a module, choose M here: the module will
> be called lenovo-wmi-other.
> +
> +config LENOVO_WMI_FAN_METHOD
> + tristate "Lenovo Fan Method WMI Driver"
> + depends on DMI
> + depends on LENOVO_WMI_TUNING
> + help
> + Say Y here to add the firmware fan table on supported Lenovo
> + Legion Go products to the Lenovo Other Mode HWMON device.
> +
> + To compile this driver as a module, choose M here: the module will
> + be called lenovo-wmi-fan-method.
> diff --git a/drivers/platform/x86/lenovo/Makefile b/drivers/platform/x86/lenovo/Makefile
> index 91a9370f11b3..171a19e01479 100644
> --- a/drivers/platform/x86/lenovo/Makefile
> +++ b/drivers/platform/x86/lenovo/Makefile
> @@ -17,6 +17,7 @@ lenovo-target-$(CONFIG_LENOVO_WMI_EVENTS) += wmi-events.o
> lenovo-target-$(CONFIG_LENOVO_WMI_HELPERS) += wmi-helpers.o
> lenovo-target-$(CONFIG_LENOVO_WMI_GAMEZONE) += wmi-gamezone.o
> lenovo-target-$(CONFIG_LENOVO_WMI_TUNING) += wmi-other.o
> +lenovo-target-$(CONFIG_LENOVO_WMI_FAN_METHOD) += wmi-fan-method.o
>
> # Add 'lenovo' prefix to each module listed in lenovo-target-*
> define LENOVO_OBJ_TARGET
> diff --git a/drivers/platform/x86/lenovo/wmi-fan-method.c b/drivers/platform/x86/lenovo/wmi-fan-method.c
> new file mode 100644
> index 000000000000..4f29c4134caf
> --- /dev/null
> +++ b/drivers/platform/x86/lenovo/wmi-fan-method.c
> @@ -0,0 +1,380 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Lenovo Fan Method WMI interface driver.
> + *
> + * This driver exposes the firmware fan table through HWMON automatic-point
> + * attributes on selected Lenovo Legion Go products.
> + */
> +
> +#include <linux/cleanup.h>
> +#include <linux/component.h>
> +#include <linux/device.h>
> +#include <linux/dmi.h>
> +#include <linux/err.h>
> +#include <linux/kernel.h>
> +#include <linux/limits.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/sysfs.h>
> +#include <linux/types.h>
> +#include <linux/unaligned.h>
> +#include <linux/wmi.h>
> +
> +#define LENOVO_FAN_METHOD_GUID "92549549-4BDE-4F06-AC04-CE8BF898DBAA"
> +
> +#define LENOVO_FAN_METHOD_GET_CURVE 5
> +#define LENOVO_FAN_METHOD_SET_CURVE 6
> +#define LENOVO_FAN_CURVE_POINTS 10
> +#define LENOVO_FAN_CURVE_REPLY_SIZE 88
> +#define LENOVO_FAN_CURVE_WRITE_SIZE 64
> +
> +#define LENOVO_FAN_REPLY_SPEED_COUNT_OFFSET 0
> +#define LENOVO_FAN_REPLY_SPEED_OFFSET 4
> +#define LENOVO_FAN_REPLY_TEMP_COUNT_OFFSET 44
> +#define LENOVO_FAN_REPLY_TEMP_OFFSET 48
> +
> +#define LENOVO_FAN_WRITE_SPEED_COUNT_OFFSET 2
> +#define LENOVO_FAN_WRITE_SPEED_OFFSET 6
> +#define LENOVO_FAN_WRITE_TEMP_TYPE_OFFSET 26
> +#define LENOVO_FAN_WRITE_TEMP_COUNT_OFFSET 27
> +#define LENOVO_FAN_WRITE_TEMP_OFFSET 31
> +#define LENOVO_FAN_WRITE_TRAILER_OFFSET 51
> +#define LENOVO_FAN_WRITE_TRAILER_VALUE_OFFSET 53
> +
> +#define LENOVO_FAN_WRITE_TEMP_TYPE 1
> +#define LENOVO_FAN_WRITE_TRAILER 0x5a
> +#define LENOVO_FAN_WRITE_TRAILER_VALUE 100
> +
> +static const struct dmi_system_id lwmi_fan_dmi_table[] = {
> + {
> + .ident = "Lenovo Legion Go 8APU1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8APU1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go S 8APU1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go S 8APU1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go S 8ARP1",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go S 8ARP1"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go 8ASP2",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8ASP2"),
> + },
> + },
> + {
> + .ident = "Lenovo Legion Go 8AHP2",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
> + DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "Legion Go 8AHP2"),
> + },
> + },
> + {}
> +};
> +
> +static const u16 lwmi_fan_temperatures[LENOVO_FAN_CURVE_POINTS] = {
> + 10, 20, 30, 40, 50, 60, 70, 80, 90, 100
> +};
> +
> +struct lwmi_fan_method_curve {
> + u16 speed[LENOVO_FAN_CURVE_POINTS];
> + u16 temperature[LENOVO_FAN_CURVE_POINTS];
> +};
> +
> +struct lwmi_fan_method_priv;
> +
> +struct lwmi_fan_method_attr {
> + struct device_attribute dev_attr;
> + struct lwmi_fan_method_priv *priv;
> + u8 index;
> +};
> +
> +struct lwmi_fan_method_priv {
> + struct wmi_device *wdev;
> + struct mutex lock; /* Serializes all Fan Method calls. */
> + struct lwmi_fan_method_attr point_attrs[LENOVO_FAN_CURVE_POINTS * 2];
> + struct attribute *attrs[LENOVO_FAN_CURVE_POINTS * 2 + 1];
> + struct attribute_group group;
> +};
> +
> +static int lwmi_fan_method_get_curve(struct lwmi_fan_method_priv *priv,
> + struct lwmi_fan_method_curve *curve)
> +{
> + u8 input[] = { 1, 1 };
> + struct wmi_buffer in = {
> + .length = sizeof(input),
> + .data = input,
> + };
> + struct wmi_buffer out = {};
> + const u8 *buffer;
> + int ret, i;
> +
> + ret = wmidev_invoke_method(priv->wdev, 0,
> + LENOVO_FAN_METHOD_GET_CURVE, &in, &out,
> + LENOVO_FAN_CURVE_REPLY_SIZE);
> + if (ret)
> + return ret;
> +
> + buffer = out.data;
> + if (get_unaligned_le32(buffer + LENOVO_FAN_REPLY_SPEED_COUNT_OFFSET) !=
> + LENOVO_FAN_CURVE_POINTS ||
> + get_unaligned_le32(buffer + LENOVO_FAN_REPLY_TEMP_COUNT_OFFSET) !=
> + LENOVO_FAN_CURVE_POINTS) {
> + ret = -ERANGE;
> + goto out_free;
> + }
> +
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++) {
> + u32 speed = get_unaligned_le32(buffer + LENOVO_FAN_REPLY_SPEED_OFFSET +
> + i * sizeof(u32));
> + u32 temperature =
> + get_unaligned_le32(buffer + LENOVO_FAN_REPLY_TEMP_OFFSET +
> + i * sizeof(u32));
> +
> + if (speed > U8_MAX || temperature != lwmi_fan_temperatures[i]) {
> + ret = -ERANGE;
> + goto out_free;
> + }
> +
> + curve->speed[i] = speed;
> + curve->temperature[i] = temperature;
> + }
> +
> +out_free:
> + kfree(out.data);
> + return ret;
> +}
> +
> +static int lwmi_fan_method_set_curve(struct lwmi_fan_method_priv *priv,
> + const struct lwmi_fan_method_curve *curve)
> +{
> + u8 buffer[LENOVO_FAN_CURVE_WRITE_SIZE] = { 0xff, 0x01 };
> + struct wmi_buffer in = {
> + .length = sizeof(buffer),
> + .data = buffer,
> + };
> + int i;
> +
> + put_unaligned_le32(LENOVO_FAN_CURVE_POINTS,
> + buffer + LENOVO_FAN_WRITE_SPEED_COUNT_OFFSET);
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++)
> + put_unaligned_le16(curve->speed[i],
> + buffer + LENOVO_FAN_WRITE_SPEED_OFFSET +
> + i * sizeof(u16));
> +
> + buffer[LENOVO_FAN_WRITE_TEMP_TYPE_OFFSET] = LENOVO_FAN_WRITE_TEMP_TYPE;
> + put_unaligned_le32(LENOVO_FAN_CURVE_POINTS,
> + buffer + LENOVO_FAN_WRITE_TEMP_COUNT_OFFSET);
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++)
> + put_unaligned_le16(curve->temperature[i],
> + buffer + LENOVO_FAN_WRITE_TEMP_OFFSET +
> + i * sizeof(u16));
> +
> + buffer[LENOVO_FAN_WRITE_TRAILER_OFFSET] = LENOVO_FAN_WRITE_TRAILER;
> + put_unaligned_le16(LENOVO_FAN_WRITE_TRAILER_VALUE,
> + buffer + LENOVO_FAN_WRITE_TRAILER_VALUE_OFFSET);
> +
> + return wmidev_invoke_procedure(priv->wdev, 0,
> + LENOVO_FAN_METHOD_SET_CURVE, &in);
> +}
> +
> +static ssize_t lwmi_fan_method_pwm_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> + struct lwmi_fan_method_priv *priv = point_attr->priv;
> + struct lwmi_fan_method_curve curve;
> + int ret;
> +
> + guard(mutex)(&priv->lock);
> +
> + ret = lwmi_fan_method_get_curve(priv, &curve);
> + if (ret)
> + return ret;
> +
> + return sysfs_emit(buf, "%u\n", curve.speed[point_attr->index]);
> +}
> +
> +static ssize_t lwmi_fan_method_pwm_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> + struct lwmi_fan_method_priv *priv = point_attr->priv;
> + struct lwmi_fan_method_curve curve;
> + unsigned long pwm;
> + int ret;
> +
> + ret = kstrtoul(buf, 10, &pwm);
> + if (ret)
> + return ret;
> + if (pwm > U8_MAX)
> + return -EINVAL;
> +
> + guard(mutex)(&priv->lock);
> +
> + ret = lwmi_fan_method_get_curve(priv, &curve);
> + if (ret)
> + return ret;
> +
> + curve.speed[point_attr->index] = pwm;
> + ret = lwmi_fan_method_set_curve(priv, &curve);
> +
> + return ret ? ret : count;
> +}
> +
> +static ssize_t lwmi_fan_method_temp_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct lwmi_fan_method_attr *point_attr =
> + container_of(attr, struct lwmi_fan_method_attr, dev_attr);
> +
> + return sysfs_emit(buf, "%u\n",
> + lwmi_fan_temperatures[point_attr->index] * 1000);
> +}
> +
> +#define LWMI_FAN_METHOD_POINT_NAMES(_point) \
> + "pwm1_auto_point" #_point "_pwm", \
> + "pwm1_auto_point" #_point "_temp"
> +
> +static const char * const lwmi_fan_method_attr_names[] = {
> + LWMI_FAN_METHOD_POINT_NAMES(1),
> + LWMI_FAN_METHOD_POINT_NAMES(2),
> + LWMI_FAN_METHOD_POINT_NAMES(3),
> + LWMI_FAN_METHOD_POINT_NAMES(4),
> + LWMI_FAN_METHOD_POINT_NAMES(5),
> + LWMI_FAN_METHOD_POINT_NAMES(6),
> + LWMI_FAN_METHOD_POINT_NAMES(7),
> + LWMI_FAN_METHOD_POINT_NAMES(8),
> + LWMI_FAN_METHOD_POINT_NAMES(9),
> + LWMI_FAN_METHOD_POINT_NAMES(10),
> +};
> +
> +#undef LWMI_FAN_METHOD_POINT_NAMES
> +
> +static void lwmi_fan_method_attrs_init(struct lwmi_fan_method_priv *priv)
> +{
> + int i;
> +
> + for (i = 0; i < LENOVO_FAN_CURVE_POINTS; i++) {
> + struct lwmi_fan_method_attr *pwm = &priv->point_attrs[i * 2];
> + struct lwmi_fan_method_attr *temp = &priv->point_attrs[i * 2 + 1];
> +
> + sysfs_attr_init(&pwm->dev_attr.attr);
> + pwm->dev_attr.attr.name = lwmi_fan_method_attr_names[i * 2];
> + pwm->dev_attr.attr.mode = 0644;
> + pwm->dev_attr.show = lwmi_fan_method_pwm_show;
> + pwm->dev_attr.store = lwmi_fan_method_pwm_store;
> + pwm->priv = priv;
> + pwm->index = i;
> + priv->attrs[i * 2] = &pwm->dev_attr.attr;
> +
> + sysfs_attr_init(&temp->dev_attr.attr);
> + temp->dev_attr.attr.name = lwmi_fan_method_attr_names[i * 2 + 1];
> + temp->dev_attr.attr.mode = 0444;
> + temp->dev_attr.show = lwmi_fan_method_temp_show;
> + temp->index = i;
> + priv->attrs[i * 2 + 1] = &temp->dev_attr.attr;
> + }
> +
> + priv->group.attrs = priv->attrs;
> +}
> +
> +static int lwmi_fan_method_master_bind(struct device *dev)
> +{
> + struct lwmi_fan_method_priv *priv = dev_get_drvdata(dev);
> +
> + return component_bind_all(dev, &priv->group);
> +}
> +
> +static void lwmi_fan_method_master_unbind(struct device *dev)
> +{
> + component_unbind_all(dev, NULL);
> +}
> +
> +static const struct component_master_ops lwmi_fan_method_master_ops = {
> + .bind = lwmi_fan_method_master_bind,
> + .unbind = lwmi_fan_method_master_unbind,
> +};
> +
> +static int lwmi_fan_method_component_compare(struct device *dev, void *data)
> +{
> + struct device *master = data;
> +
> + return dev->driver &&
> + !strcmp(dev->driver->name, "lenovo_wmi_other") &&
> + dev->parent == master->parent;
> +}
> +
> +static int lwmi_fan_method_probe(struct wmi_device *wdev, const void *context)
> +{
> + struct component_match *master_match = NULL;
> + struct lwmi_fan_method_priv *priv;
> +
> + if (!dmi_check_system(lwmi_fan_dmi_table))
> + return -ENODEV;
> +
> + priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->wdev = wdev;
> + mutex_init(&priv->lock);
> + lwmi_fan_method_attrs_init(priv);
> + dev_set_drvdata(&wdev->dev, priv);
> +
> + component_match_add(&wdev->dev, &master_match,
> + lwmi_fan_method_component_compare, &wdev->dev);
> + if (IS_ERR(master_match))
> + return PTR_ERR(master_match);
> +
> + return component_master_add_with_match(&wdev->dev,
> + &lwmi_fan_method_master_ops,
> + master_match);
> +}
> +
> +static void lwmi_fan_method_remove(struct wmi_device *wdev)
> +{
> + component_master_del(&wdev->dev, &lwmi_fan_method_master_ops);
> +}
> +
> +static const struct wmi_device_id lwmi_fan_method_id_table[] = {
> + { LENOVO_FAN_METHOD_GUID, NULL },
> + {}
> +};
> +
> +static struct wmi_driver lwmi_fan_method_driver = {
> + .driver = {
> + .name = "lenovo_wmi_fan_method",
> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> + },
> + .id_table = lwmi_fan_method_id_table,
> + .probe = lwmi_fan_method_probe,
> + .remove = lwmi_fan_method_remove,
> + .no_singleton = true,
> +};
> +
> +MODULE_DEVICE_TABLE(wmi, lwmi_fan_method_id_table);
> +module_wmi_driver(lwmi_fan_method_driver);
> +
> +MODULE_AUTHOR("Aditya Dash <mradityadash@gmail.com>");
> +MODULE_DESCRIPTION("Lenovo Fan Method WMI Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c
> index b4be7739b243..72d3510b17b2 100644
> --- a/drivers/platform/x86/lenovo/wmi-other.c
> +++ b/drivers/platform/x86/lenovo/wmi-other.c
> @@ -192,11 +192,13 @@ struct lwmi_om_priv {
> struct device *fw_attr_dev;
> struct kset *fw_attr_kset;
> struct wmi_device *wdev;
> + const struct attribute_group *fan_method_group;
> int ida_id;
>
> struct lwmi_fan_info fan_info[LWMI_FAN_NR];
> bool fullspeed_supported;
> bool fan0_input_fallback;
> + bool fan_method_group_added;
>
> struct {
> bool capdata00_collected : 1;
> @@ -542,6 +544,31 @@ static const struct hwmon_chip_info lwmi_om_hwmon_chip_info = {
> .info = lwmi_om_hwmon_info,
> };
>
> +static int lwmi_om_fan_method_group_add(struct lwmi_om_priv *priv)
> +{
> + int ret;
> +
> + if (!priv->hwmon_dev || !priv->fan_method_group ||
> + priv->fan_method_group_added)
> + return 0;
> +
> + ret = sysfs_create_group(&priv->hwmon_dev->kobj,
> + priv->fan_method_group);
> + if (!ret)
> + priv->fan_method_group_added = true;
> +
> + return ret;
> +}
> +
> +static void lwmi_om_fan_method_group_remove(struct lwmi_om_priv *priv)
> +{
> + if (!priv->hwmon_dev || !priv->fan_method_group_added)
> + return;
> +
> + sysfs_remove_group(&priv->hwmon_dev->kobj, priv->fan_method_group);
> + priv->fan_method_group_added = false;
> +}
> +
> /**
> * lwmi_om_hwmon_add() - Register HWMON device if all info is collected
> * @priv: Driver private data
> @@ -550,9 +577,9 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> {
> u32 rpm;
> long enable;
> - int i, valid;
> + int i, ret, valid;
>
> - if (WARN_ON(priv->hwmon_dev))
> + if (priv->hwmon_dev)
> return;
>
> if (!priv->fan_flags.capdata00_collected || !priv->fan_flags.capdata_fan_collected) {
> @@ -592,7 +619,8 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> }
> }
>
> - if (valid == 0 && !priv->fullspeed_supported && !priv->fan0_input_fallback) {
> + if (valid == 0 && !priv->fullspeed_supported &&
> + !priv->fan0_input_fallback && !priv->fan_method_group) {
> dev_warn(&priv->wdev->dev,
> "fan reporting/tuning is unsupported on this device\n");
> return;
> @@ -609,6 +637,11 @@ static void lwmi_om_hwmon_add(struct lwmi_om_priv *priv)
> return;
> }
>
> + ret = lwmi_om_fan_method_group_add(priv);
> + if (ret)
> + dev_warn(&priv->wdev->dev,
> + "failed to register Fan Method attributes: %d\n", ret);
> +
> dev_dbg(&priv->wdev->dev, "registered HWMON device\n");
> }
>
> @@ -623,6 +656,7 @@ static void lwmi_om_hwmon_remove(struct lwmi_om_priv *priv)
> if (!priv->hwmon_dev)
> return;
>
> + lwmi_om_fan_method_group_remove(priv);
> hwmon_device_unregister(priv->hwmon_dev);
> priv->hwmon_dev = NULL;
> }
> @@ -1801,10 +1835,44 @@ static const struct component_master_ops lwmi_om_master_ops = {
> .unbind = lwmi_om_master_unbind,
> };
>
> +static int lwmi_om_fan_method_component_bind(struct device *component,
> + struct device *master, void *data)
> +{
> + const struct attribute_group *group = data;
> + struct lwmi_om_priv *priv = dev_get_drvdata(component);
> + int ret;
> +
> + if (!group)
> + return -EINVAL;
> +
> + priv->fan_method_group = group;
> + lwmi_om_hwmon_add(priv);
> + ret = lwmi_om_fan_method_group_add(priv);
> + if (ret)
> + priv->fan_method_group = NULL;
> +
> + return ret;
> +}
> +
> +static void lwmi_om_fan_method_component_unbind(struct device *component,
> + struct device *master, void *data)
> +{
> + struct lwmi_om_priv *priv = dev_get_drvdata(component);
> +
> + lwmi_om_fan_method_group_remove(priv);
> + priv->fan_method_group = NULL;
> +}
> +
> +static const struct component_ops lwmi_om_fan_method_component_ops = {
> + .bind = lwmi_om_fan_method_component_bind,
> + .unbind = lwmi_om_fan_method_component_unbind,
> +};
> +
> static int lwmi_other_probe(struct wmi_device *wdev, const void *context)
> {
> struct component_match *master_match = NULL;
> struct lwmi_om_priv *priv;
> + int ret;
>
> priv = devm_kzalloc(&wdev->dev, sizeof(*priv), GFP_KERNEL);
> if (!priv)
> @@ -1816,16 +1884,31 @@ static int lwmi_other_probe(struct wmi_device *wdev, const void *context)
> priv->wdev = wdev;
> dev_set_drvdata(&wdev->dev, priv);
>
> + ret = component_add(&wdev->dev, &lwmi_om_fan_method_component_ops);
> + if (ret)
> + return ret;
> +
> lwmi_cd_match_add_all(&wdev->dev, &master_match);
> - if (IS_ERR(master_match))
> - return PTR_ERR(master_match);
> + if (IS_ERR(master_match)) {
> + ret = PTR_ERR(master_match);
> + goto err_component;
> + }
> +
> + ret = component_master_add_with_match(&wdev->dev, &lwmi_om_master_ops,
> + master_match);
> + if (ret)
> + goto err_component;
> +
> + return 0;
>
> - return component_master_add_with_match(&wdev->dev, &lwmi_om_master_ops,
> - master_match);
> +err_component:
> + component_del(&wdev->dev, &lwmi_om_fan_method_component_ops);
> + return ret;
> }
>
> static void lwmi_other_remove(struct wmi_device *wdev)
> {
> + component_del(&wdev->dev, &lwmi_om_fan_method_component_ops);
> component_master_del(&wdev->dev, &lwmi_om_master_ops);
> }
>
> --
> 2.55.0
>
^ permalink raw reply [flat|nested] 18+ messages in thread