On Tue, Jan 30, 2024 at 07:58:55PM -0500, Ivor Wanders wrote: > Adds a driver that provides read only access to the fan speed for Microsoft > Surface Pro devices. The fan speed is always regulated by the EC and cannot > be influenced directly. > > Signed-off-by: Ivor Wanders <ivor@xxxxxxxxxxxx> > Link: https://github.com/linux-surface/kernel/pull/144 > Reviewed-by: Maximilian Luz <luzmaximilian@xxxxxxxxx> > Reviewed-by: Armin Wolf <W_Armin@xxxxxx> Applied. Thanks, Guenter > --- > Changes in v5: > - No changes in this patch. > Changes in v4: > - Return 0 from surface_fan_hwmon_read instead of ret. > - Use PTR_ERR_OR_ZERO in probe instead of if statement. > Changes in v3: > - Removed type and attr checks in read and is_visible. > - Removed assigning sdev to ssam_device drvdata. > - Propagate return from __ssam_fan_rpm_get. > - Renamed hwmon chip name from 'fan' to 'surface_fan'. > - Removed unnecessary platform_device header. > Changes in v2: > - Removed all sysfs attributes except fan1_input. Simplified code > and updated documentation accordingly. > --- > Documentation/hwmon/index.rst | 1 + > Documentation/hwmon/surface_fan.rst | 25 ++++++++ > MAINTAINERS | 8 +++ > drivers/hwmon/Kconfig | 13 +++++ > drivers/hwmon/Makefile | 1 + > drivers/hwmon/surface_fan.c | 91 +++++++++++++++++++++++++++++ > 6 files changed, 139 insertions(+) > create mode 100644 Documentation/hwmon/surface_fan.rst > create mode 100644 drivers/hwmon/surface_fan.c > > diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst > index c7ed1f73a..58be92e94 100644 > --- a/Documentation/hwmon/index.rst > +++ b/Documentation/hwmon/index.rst > @@ -208,6 +208,7 @@ Hardware Monitoring Kernel Drivers > smsc47m1 > sparx5-temp > stpddc60 > + surface_fan > sy7636a-hwmon > tc654 > tc74 > diff --git a/Documentation/hwmon/surface_fan.rst b/Documentation/hwmon/surface_fan.rst > new file mode 100644 > index 000000000..07942574c > --- /dev/null > +++ b/Documentation/hwmon/surface_fan.rst > @@ -0,0 +1,25 @@ > +.. SPDX-License-Identifier: GPL-2.0-or-later > + > +Kernel driver surface_fan > +========================= > + > +Supported Devices: > + > + * Microsoft Surface Pro 9 > + > +Author: Ivor Wanders <ivor@xxxxxxxxxxxx> > + > +Description > +----------- > + > +This provides monitoring of the fan found in some Microsoft Surface Pro devices, > +like the Surface Pro 9. The fan is always controlled by the onboard controller. > + > +Sysfs interface > +--------------- > + > +======================= ======= ========================================= > +Name Perm Description > +======================= ======= ========================================= > +``fan1_input`` RO Current fan speed in RPM. > +======================= ======= ========================================= > diff --git a/MAINTAINERS b/MAINTAINERS > index c4828ab15..2c5c4d7e5 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -14560,6 +14560,14 @@ F: Documentation/driver-api/surface_aggregator/clients/dtx.rst > F: drivers/platform/surface/surface_dtx.c > F: include/uapi/linux/surface_aggregator/dtx.h > > +MICROSOFT SURFACE SENSOR FAN DRIVER > +M: Maximilian Luz <luzmaximilian@xxxxxxxxx> > +M: Ivor Wanders <ivor@xxxxxxxxxxxx> > +L: linux-hwmon@xxxxxxxxxxxxxxx > +S: Maintained > +F: Documentation/hwmon/surface_fan.rst > +F: drivers/hwmon/surface_fan.c > + > MICROSOFT SURFACE GPE LID SUPPORT DRIVER > M: Maximilian Luz <luzmaximilian@xxxxxxxxx> > L: platform-driver-x86@xxxxxxxxxxxxxxx > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index a608264da..e762f6138 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -1994,6 +1994,19 @@ config SENSORS_SFCTEMP > This driver can also be built as a module. If so, the module > will be called sfctemp. > > +config SENSORS_SURFACE_FAN > + tristate "Surface Fan Driver" > + depends on SURFACE_AGGREGATOR > + help > + Driver that provides monitoring of the fan on Surface Pro devices that > + have a fan, like the Surface Pro 9. > + > + This makes the fan's current speed accessible through the hwmon > + system. It does not provide control over the fan, the firmware is > + responsible for that, this driver merely provides monitoring. > + > + Select M or Y here, if you want to be able to read the fan's speed. > + > config SENSORS_ADC128D818 > tristate "Texas Instruments ADC128D818" > depends on I2C > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 47be39af5..30cc90f40 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -201,6 +201,7 @@ obj-$(CONFIG_SENSORS_SMSC47M1) += smsc47m1.o > obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o > obj-$(CONFIG_SENSORS_SPARX5) += sparx5-temp.o > obj-$(CONFIG_SENSORS_STTS751) += stts751.o > +obj-$(CONFIG_SENSORS_SURFACE_FAN)+= surface_fan.o > obj-$(CONFIG_SENSORS_SY7636A) += sy7636a-hwmon.o > obj-$(CONFIG_SENSORS_AMC6821) += amc6821.o > obj-$(CONFIG_SENSORS_TC74) += tc74.o > diff --git a/drivers/hwmon/surface_fan.c b/drivers/hwmon/surface_fan.c > new file mode 100644 > index 000000000..31cd5da9e > --- /dev/null > +++ b/drivers/hwmon/surface_fan.c > @@ -0,0 +1,91 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Surface Fan driver for Surface System Aggregator Module. It provides access > + * to the fan's rpm through the hwmon system. > + * > + * Copyright (C) 2023 Ivor Wanders <ivor@xxxxxxxxxxxx> > + */ > + > +#include <linux/hwmon.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/surface_aggregator/device.h> > +#include <linux/types.h> > + > +// SSAM > +SSAM_DEFINE_SYNC_REQUEST_CL_R(__ssam_fan_rpm_get, __le16, { > + .target_category = SSAM_SSH_TC_FAN, > + .command_id = 0x01, > +}); > + > +// hwmon > +umode_t surface_fan_hwmon_is_visible(const void *drvdata, > + enum hwmon_sensor_types type, u32 attr, > + int channel) > +{ > + return 0444; > +} > + > +static int surface_fan_hwmon_read(struct device *dev, > + enum hwmon_sensor_types type, u32 attr, > + int channel, long *val) > +{ > + struct ssam_device *sdev = dev_get_drvdata(dev); > + int ret; > + __le16 value; > + > + ret = __ssam_fan_rpm_get(sdev, &value); > + if (ret) > + return ret; > + > + *val = le16_to_cpu(value); > + > + return 0; > +} > + > +static const struct hwmon_channel_info *const surface_fan_info[] = { > + HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT), > + NULL > +}; > + > +static const struct hwmon_ops surface_fan_hwmon_ops = { > + .is_visible = surface_fan_hwmon_is_visible, > + .read = surface_fan_hwmon_read, > +}; > + > +static const struct hwmon_chip_info surface_fan_chip_info = { > + .ops = &surface_fan_hwmon_ops, > + .info = surface_fan_info, > +}; > + > +static int surface_fan_probe(struct ssam_device *sdev) > +{ > + struct device *hdev; > + > + hdev = devm_hwmon_device_register_with_info(&sdev->dev, > + "surface_fan", sdev, > + &surface_fan_chip_info, > + NULL); > + > + return PTR_ERR_OR_ZERO(hdev); > +} > + > +static const struct ssam_device_id ssam_fan_match[] = { > + { SSAM_SDEV(FAN, SAM, 0x01, 0x01) }, > + {}, > +}; > +MODULE_DEVICE_TABLE(ssam, ssam_fan_match); > + > +static struct ssam_device_driver surface_fan = { > + .probe = surface_fan_probe, > + .match_table = ssam_fan_match, > + .driver = { > + .name = "surface_fan", > + .probe_type = PROBE_PREFER_ASYNCHRONOUS, > + }, > +}; > +module_ssam_device_driver(surface_fan); > + > +MODULE_AUTHOR("Ivor Wanders <ivor@xxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Fan Driver for Surface System Aggregator Module"); > +MODULE_LICENSE("GPL");
