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Date: Thu, 6 Apr 2023 18:04:43 +0200
From: Armin Wolf <W_Armin@....de>
To: James Seo <james@...iv.tech>
Cc: Jean Delvare <jdelvare@...e.com>,
Guenter Roeck <linux@...ck-us.net>,
linux-hwmon@...r.kernel.org, platform-driver-x86@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] hwmon: add HP WMI Sensors driver
Am 06.04.23 um 17:23 schrieb James Seo:
> Hewlett-Packard business-class computers report hardware monitoring
> information via WMI. This driver exposes that information to hwmon.
> Initial support is provided for temperature, voltage, current, and
> fan speed sensor types.
>
> HP's WMI implementation permits many other types of numeric sensors.
> Therefore, a debugfs interface is also provided to enumerate and
> inspect all numeric sensors visible on the WMI side. This should
> facilitate adding support for other sensor types in the future.
>
> Tested on a HP Z420 and a HP EliteOne 800 G1.
>
> Note that these models only have temperature and fan speed sensors,
> so other sensor types have not been tested working yet. However, the
> driver should still work as expected. A 2005 HP whitepaper describes
> the relevant MOF definition and sensor value calculation, and both
> this driver and the official HP Performance Advisor utility comply
> with them (confirmed in the latter case by reverse engineering).
>
> Link: https://h20331.www2.hp.com/hpsub/downloads/cmi_whitepaper.pdf
> Signed-off-by: James Seo <james@...iv.tech>
>
> ---
>
> Changes in v2:
> * Reword commit message
> * Reword documentation
> * Remove stray #include
> * Use DIV_ROUND_CLOSEST in F to C conversion
> * Consolidate uses of mutex_lock()/mutex_unlock()
> * Process sensors in forward order by type
>
> History:
> v1: https://lore.kernel.org/linux-hwmon/20230403084859.26286-1-james@equiv.tech/
> ---
> Documentation/hwmon/hp-wmi-sensors.rst | 95 +++
> Documentation/hwmon/index.rst | 1 +
> MAINTAINERS | 7 +
> drivers/hwmon/Kconfig | 11 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/hp-wmi-sensors.c | 1034 ++++++++++++++++++++++++
> 6 files changed, 1149 insertions(+)
> create mode 100644 Documentation/hwmon/hp-wmi-sensors.rst
> create mode 100644 drivers/hwmon/hp-wmi-sensors.c
>
> diff --git a/Documentation/hwmon/hp-wmi-sensors.rst b/Documentation/hwmon/hp-wmi-sensors.rst
> new file mode 100644
> index 000000000000..71b1391d5072
> --- /dev/null
> +++ b/Documentation/hwmon/hp-wmi-sensors.rst
> @@ -0,0 +1,95 @@
> +.. SPDX-License-Identifier: GPL-2.0-or-later
> +
> +.. include:: <isonum.txt>
> +
> +Linux HP WMI Sensors Driver
> +===========================
> +
> +:Copyright: |copy| 2023 James Seo <james@...iv.tech>
> +
> +Description
> +-----------
> +
> +Hewlett-Packard business-class computers report hardware monitoring information
> +via Windows Management Instrumentation (WMI). This driver exposes that
> +information to the Linux ``hwmon`` subsystem, allowing familiar userspace
> +utilities like ``sensors`` to gather numeric sensor readings.
> +
> +``sysfs`` interface
> +-------------------
> +
> +When the driver is loaded, it discovers the sensors available on the current
> +system and creates the following read-only ``sysfs`` attributes as appropriate
> +within ``/sys/class/hwmon/hwmonX``:
> +
> +================ ==================================================
> +Name Description
> +================ ==================================================
> +curr[X]_input Current in milliamperes (mA).
> +curr[X]_label Current sensor label.
> +fan[X]_input Fan speed in RPM.
> +fan[X]_label Fan sensor label.
> +fan[X]_fault Fan sensor fault indicator.
> +in[X]_input Voltage in millivolts (mV).
> +in[X]_label Voltage sensor label.
> +temp[X]_input Temperature in millidegrees Celsius (m\ |deg|\ C).
> +temp[X]_label Temperature sensor label.
> +temp[X]_fault Temperature sensor fault indicator.
> +================ ==================================================
> +
> +Here, ``X`` is some number that depends on other available sensors and on other
> +system hardware components.
> +
> +``fault`` attributes
> + Reading ``1`` instead of ``0`` as the ``fault`` attribute for a sensor
> + indicates that the sensor has encountered some issue during operation such
> + that measurements from it should no longer be trusted.
> +
> +``debugfs`` interface
> +---------------------
> +
> +The standard ``hwmon`` interface in ``sysfs`` exposes sensors of several common
> +types that are connected and operating normally as of driver initialization.
> +However, there are usually other sensors on the WMI side that do not meet these
> +criteria. This driver therefore provides a ``debugfs`` interface in
> +``/sys/kernel/debug/hp-wmi-sensors-X`` that allows read-only access to *all* HP
> +WMI sensors on the current system.
> +
> +.. warning:: The ``debugfs`` interface is only available when the kernel is
> + compiled with option ``CONFIG_DEBUG_FS``, and its implementation
> + is subject to change without notice at any time.
> +
> +One numbered entry is created per sensor with the following attributes:
> +
> +=============================== ==========================================
> +Name Example
> +=============================== ==========================================
> +name ``CPU0 Fan``
> +description ``Reports CPU0 fan speed``
> +sensor_type ``12``
> +other_sensor_type ``(null)``
> +operational_status ``2``
> +current_state ``Normal``
> +possible_states ``Normal\nCaution\nCritical\nNot Present``
> +base_units ``19``
> +unit_modifier ``0``
> +current_reading ``1008``
> +=============================== ==========================================
> +
> +These represent the properties of the underlying ``HP_BIOSNumericSensor`` WMI
> +object. Contents may vary somewhat between systems. See [#]_ for more details.
> +
> +Known issues and limitations
> +----------------------------
> +
> +- Non-numeric HP sensor types such as intrusion sensors that belong to the
> + ``HP_BIOSStateSensor`` WMI object type are not supported.
> +- HP's WMI implementation permits sensors to claim to be of any type.
> + However, only sensor types already known to hwmon can be supported.
> +
> +References
> +----------
> +
> +.. [#] Hewlett-Packard Development Company, L.P.,
> + "HP Client Management Interface Technical White Paper", 2005. [Online].
> + Available: https://h20331.www2.hp.com/hpsub/downloads/cmi_whitepaper.pdf
> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index f1fe75f596a5..f8f3c0bef6ed 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -77,6 +77,7 @@ Hardware Monitoring Kernel Drivers
> gl518sm
> gxp-fan-ctrl
> hih6130
> + hp-wmi-sensors
> ibmaem
> ibm-cffps
> ibmpowernv
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 90abe83c02f3..264960e4c77e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9373,6 +9373,13 @@ L: platform-driver-x86@...r.kernel.org
> S: Orphan
> F: drivers/platform/x86/hp/tc1100-wmi.c
>
> +HP WMI HARDWARE MONITOR DRIVER
> +M: James Seo <james@...iv.tech>
> +L: linux-hwmon@...r.kernel.org
> +S: Maintained
> +F: Documentation/hwmon/hp-wmi-sensors.rst
> +F: drivers/hwmon/hp-wmi-sensors.c
> +
> HPET: High Precision Event Timers driver
> M: Clemens Ladisch <clemens@...isch.de>
> S: Maintained
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 5b3b76477b0e..78798e0ed5e6 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -2399,6 +2399,17 @@ config SENSORS_ASUS_EC
> This driver can also be built as a module. If so, the module
> will be called asus_ec_sensors.
>
> +config SENSORS_HP_WMI
> + tristate "HP WMI Sensors"
> + depends on ACPI_WMI
> + help
> + If you say yes here you get support for the ACPI hardware monitoring
> + interface found in HP business-class computers. Temperature, voltage,
> + current, and fan speed sensor types are supported if present.
> +
> + This driver can also be built as a module. If so, the module
> + will be called hp_wmi_sensors.
> +
> endif # ACPI
>
> endif # HWMON
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 88712b5031c8..05cce16f37f6 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -11,6 +11,7 @@ obj-$(CONFIG_SENSORS_ACPI_POWER) += acpi_power_meter.o
> obj-$(CONFIG_SENSORS_ATK0110) += asus_atk0110.o
> obj-$(CONFIG_SENSORS_ASUS_EC) += asus-ec-sensors.o
> obj-$(CONFIG_SENSORS_ASUS_WMI) += asus_wmi_sensors.o
> +obj-$(CONFIG_SENSORS_HP_WMI) += hp-wmi-sensors.o
>
> # Native drivers
> # asb100, then w83781d go first, as they can override other drivers' addresses.
> diff --git a/drivers/hwmon/hp-wmi-sensors.c b/drivers/hwmon/hp-wmi-sensors.c
> new file mode 100644
> index 000000000000..8c1f09fcdfce
> --- /dev/null
> +++ b/drivers/hwmon/hp-wmi-sensors.c
> @@ -0,0 +1,1034 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * hwmon driver for HP business-class computers that report numeric
> + * sensor data via Windows Management Instrumentation (WMI).
> + *
> + * Copyright (C) 2023 James Seo <james@...iv.tech>
> + *
> + * References:
> + * [1] Hewlett-Packard Development Company, L.P.,
> + * "HP Client Management Interface Technical White Paper", 2005. [Online].
> + * Available: https://h20331.www2.hp.com/hpsub/downloads/cmi_whitepaper.pdf
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/debugfs.h>
> +#include <linux/hwmon.h>
> +#include <linux/jiffies.h>
> +#include <linux/mutex.h>
> +#include <linux/units.h>
> +#include <linux/wmi.h>
> +
> +/*
> + * MOF definition of the HP_BIOSNumericSensor WMI object [1]:
> + *
> + * #pragma namespace("\\\\.\\root\\HP\\InstrumentedBIOS");
> + *
> + * [abstract]
> + * class HP_BIOSSensor
> + * {
> + * [read] string Name;
> + * [read] string Description;
> + * [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
> + * "10","11","12"}, Values {"Unknown","Other","Temperature",
> + * "Voltage","Current","Tachometer","Counter","Switch","Lock",
> + * "Humidity","Smoke Detection","Presence","Air Flow"}]
> + * uint32 SensorType;
> + * [read] string OtherSensorType;
> + * [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
> + * "10","11","12","13","14","15","16","17","18","..",
> + * "0x8000.."}, Values {"Unknown","Other","OK","Degraded",
> + * "Stressed","Predictive Failure","Error",
> + * "Non-Recoverable Error","Starting","Stopping","Stopped",
> + * "In Service","No Contact","Lost Communication","Aborted",
> + * "Dormant","Supporting Entity in Error","Completed",
> + * "Power Mode","DMTF Reserved","Vendor Reserved"}]
> + * uint32 OperationalStatus;
> + * [read] string CurrentState;
> + * [read] string PossibleStates[];
> + * };
> + *
> + * class HP_BIOSNumericSensor : HP_BIOSSensor
> + * {
> + * [read, ValueMap {"0","1","2","3","4","5","6","7","8","9",
> + * "10","11","12","13","14","15","16","17","18","19","20",
> + * "21","22","23","24","25","26","27","28","29","30","31",
> + * "32","33","34","35","36","37","38","39","40","41","42",
> + * "43","44","45","46","47","48","49","50","51","52","53",
> + * "54","55","56","57","58","59","60","61","62","63","64",
> + * "65"}, Values {"Unknown","Other","Degrees C","Degrees F",
> + * "Degrees K","Volts","Amps","Watts","Joules","Coulombs",
> + * "VA","Nits","Lumens","Lux","Candelas","kPa","PSI",
> + * "Newtons","CFM","RPM","Hertz","Seconds","Minutes",
> + * "Hours","Days","Weeks","Mils","Inches","Feet",
> + * "Cubic Inches","Cubic Feet","Meters","Cubic Centimeters",
> + * "Cubic Meters","Liters","Fluid Ounces","Radians",
> + * "Steradians","Revolutions","Cycles","Gravities","Ounces",
> + * "Pounds","Foot-Pounds","Ounce-Inches","Gauss","Gilberts",
> + * "Henries","Farads","Ohms","Siemens","Moles","Becquerels",
> + * "PPM (parts/million)","Decibels","DbA","DbC","Grays",
> + * "Sieverts","Color Temperature Degrees K","Bits","Bytes",
> + * "Words (data)","DoubleWords","QuadWords","Percentage"}]
> + * uint32 BaseUnits;
> + * [read] sint32 UnitModifier;
> + * [read] uint32 CurrentReading;
> + * };
> + *
> + */
> +
> +#define HP_WMI_BIOS_GUID "5FB7F034-2C63-45E9-BE91-3D44E2C707E4"
> +#define HP_WMI_NUMERIC_SENSOR_GUID "8F1F6435-9F42-42C8-BADC-0E9424F20C9A"
> +
> +/* These limits are arbitrary. The WMI implementation may vary by model. */
> +
> +#define HP_WMI_MAX_STR_SIZE 128U
> +#define HP_WMI_MAX_PROPERTIES 32U
> +#define HP_WMI_MAX_INSTANCES 32U
> +
> +enum hp_wmi_type {
> + HP_WMI_TYPE_OTHER = 1,
> + HP_WMI_TYPE_TEMPERATURE = 2,
> + HP_WMI_TYPE_VOLTAGE = 3,
> + HP_WMI_TYPE_CURRENT = 4,
> + HP_WMI_TYPE_AIR_FLOW = 12,
> +};
> +
> +enum hp_wmi_status {
> + HP_WMI_STATUS_OK = 2,
> +};
> +
> +enum hp_wmi_units {
> + HP_WMI_UNITS_DEGREES_C = 2,
> + HP_WMI_UNITS_DEGREES_F = 3,
> + HP_WMI_UNITS_DEGREES_K = 4,
> + HP_WMI_UNITS_VOLTS = 5,
> + HP_WMI_UNITS_AMPS = 6,
> + HP_WMI_UNITS_RPM = 19,
> +};
> +
> +enum hp_wmi_property {
> + HP_WMI_PROPERTY_NAME = 0,
> + HP_WMI_PROPERTY_DESCRIPTION = 1,
> + HP_WMI_PROPERTY_SENSOR_TYPE = 2,
> + HP_WMI_PROPERTY_OTHER_SENSOR_TYPE = 3,
> + HP_WMI_PROPERTY_OPERATIONAL_STATUS = 4,
> + HP_WMI_PROPERTY_CURRENT_STATE = 5,
> + HP_WMI_PROPERTY_POSSIBLE_STATES = 6,
> + HP_WMI_PROPERTY_BASE_UNITS = 7,
> + HP_WMI_PROPERTY_UNIT_MODIFIER = 8,
> + HP_WMI_PROPERTY_CURRENT_READING = 9,
> +};
> +
> +static const acpi_object_type hp_wmi_property_map[] = {
> + [HP_WMI_PROPERTY_NAME] = ACPI_TYPE_STRING,
> + [HP_WMI_PROPERTY_DESCRIPTION] = ACPI_TYPE_STRING,
> + [HP_WMI_PROPERTY_SENSOR_TYPE] = ACPI_TYPE_INTEGER,
> + [HP_WMI_PROPERTY_OTHER_SENSOR_TYPE] = ACPI_TYPE_STRING,
> + [HP_WMI_PROPERTY_OPERATIONAL_STATUS] = ACPI_TYPE_INTEGER,
> + [HP_WMI_PROPERTY_CURRENT_STATE] = ACPI_TYPE_STRING,
> + [HP_WMI_PROPERTY_POSSIBLE_STATES] = ACPI_TYPE_STRING,
> + [HP_WMI_PROPERTY_BASE_UNITS] = ACPI_TYPE_INTEGER,
> + [HP_WMI_PROPERTY_UNIT_MODIFIER] = ACPI_TYPE_INTEGER,
> + [HP_WMI_PROPERTY_CURRENT_READING] = ACPI_TYPE_INTEGER,
> +};
> +
> +static const enum hwmon_sensor_types hp_wmi_hwmon_type_map[] = {
> + [HP_WMI_TYPE_TEMPERATURE] = hwmon_temp,
> + [HP_WMI_TYPE_VOLTAGE] = hwmon_in,
> + [HP_WMI_TYPE_CURRENT] = hwmon_curr,
> + [HP_WMI_TYPE_AIR_FLOW] = hwmon_fan,
> +};
> +
> +static const u32 hp_wmi_hwmon_attributes[hwmon_max] = {
> + [hwmon_chip] = HWMON_C_REGISTER_TZ,
> + [hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_FAULT,
> + [hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,
> + [hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,
> + [hwmon_fan] = HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_FAULT,
> +};
> +
> +/*
> + * struct hp_wmi_numeric_sensor - a HP_BIOSNumericSensor instance
> + *
> + * Contains WMI object instance properties. See MOF definition [1].
> + */
> +struct hp_wmi_numeric_sensor {
> + const char *name;
> + const char *description;
> + u32 sensor_type;
> + const char *other_sensor_type; /* Explains "Other" SensorType. */
> + u32 operational_status;
> + const char *current_state;
> + const char **possible_states; /* Count may vary. */
> + u32 base_units;
> + s32 unit_modifier;
> + u32 current_reading;
> +
> + u8 possible_states_count;
> +};
> +
> +/*
> + * struct hp_wmi_info - sensor info
> + * @nsensor: numeric sensor properties
> + * @instance: its WMI instance number
> + * @is_active: whether the following fields are valid
> + * @type: its hwmon sensor type
> + * @cached_val: current sensor reading value, scaled for hwmon
> + * @last_updated: when these readings were last updated
> + */
> +struct hp_wmi_info {
> + struct hp_wmi_numeric_sensor nsensor;
> + u8 instance;
> +
> + bool is_active;
> + enum hwmon_sensor_types type;
> + long cached_val;
> + unsigned long last_updated; /* in jiffies */
> +};
> +
> +/*
> + * struct hp_wmi_sensors - driver state
> + * @wdev: pointer to the parent WMI device
> + * @debugfs: root directory in debugfs
> + * @info: sensor info structs for all sensors visible in WMI
> + * @info_map: access info structs by hwmon type and channel number
> + * @count: count of all sensors visible in WMI
> + * @channel_count: count of hwmon channels by hwmon type
> + * @lock: mutex to lock polling WMI and changes to driver state
> + */
> +struct hp_wmi_sensors {
> + struct wmi_device *wdev;
> + struct dentry *debugfs;
> + struct hp_wmi_info info[HP_WMI_MAX_INSTANCES];
> + struct hp_wmi_info **info_map[hwmon_max];
> + u8 count;
> + u8 channel_count[hwmon_max];
> +
> + struct mutex lock; /* lock polling WMI, driver state changes */
> +};
> +
> +/* hp_wmi_strdup - devm_kstrdup, but length-limited */
> +static char *hp_wmi_strdup(struct device *dev, const char *src, u32 len)
> +{
> + char *dst;
> +
> + len = min(len, HP_WMI_MAX_STR_SIZE - 1);
> +
> + dst = devm_kmalloc(dev, (len + 1) * sizeof(*dst), GFP_KERNEL);
> + if (!dst)
> + return NULL;
> +
> + strscpy(dst, src, len + 1);
> +
> + return dst;
> +}
> +
> +/*
> + * hp_wmi_get_wobj - poll WMI for a HP_BIOSNumericSensor object instance
> + * @state: pointer to driver state
> + * @instance: WMI object instance number
> + *
> + * Returns a new WMI object instance on success, or NULL on error.
> + * Caller must kfree the result.
> + */
> +static union acpi_object *hp_wmi_get_wobj(struct hp_wmi_sensors *state,
> + u8 instance)
> +{
> + struct wmi_device *wdev = state->wdev;
> +
> + return wmidev_block_query(wdev, instance);
> +}
> +
> +/*
> + * check_wobj - validate a HP_BIOSNumericSensor WMI object instance
> + * @wobj: pointer to WMI object instance to check
> + * @possible_states_count: out pointer to count of possible states
> + *
> + * Returns 0 on success, or a negative error code on error.
> + */
> +static int check_wobj(const union acpi_object *wobj, u8 *possible_states_count)
> +{
> + acpi_object_type type = wobj->type;
> + int prop = HP_WMI_PROPERTY_NAME;
> + acpi_object_type valid_type;
> + union acpi_object *elements;
> + u32 elem_count;
> + u8 count = 0;
> + u32 i;
> +
> + if (type != ACPI_TYPE_PACKAGE)
> + return -EINVAL;
> +
> + elem_count = wobj->package.count;
> + if (elem_count > HP_WMI_MAX_PROPERTIES)
> + return -EINVAL;
> +
> + elements = wobj->package.elements;
> + for (i = 0; i < elem_count; i++, prop++) {
> + if (prop > HP_WMI_PROPERTY_CURRENT_READING)
> + return -EINVAL;
> +
> + type = elements[i].type;
> + valid_type = hp_wmi_property_map[prop];
> + if (type != valid_type)
> + return -EINVAL;
> +
> + /*
> + * elements is a variable-length array of ACPI objects, one for
> + * each property of the WMI object instance, except that the
> + * strs in PossibleStates[] are flattened into this array, and
> + * their count is found in the WMI BMOF. We don't decode the
> + * BMOF, so find the count by finding the next int.
> + */
> +
> + if (prop == HP_WMI_PROPERTY_CURRENT_STATE) {
> + prop = HP_WMI_PROPERTY_POSSIBLE_STATES;
> + valid_type = hp_wmi_property_map[prop];
> + for (; i + 1 < elem_count; i++, count++) {
> + type = elements[i + 1].type;
> + if (type != valid_type)
> + break;
> + }
> + }
> + }
> +
> + if (!count || prop <= HP_WMI_PROPERTY_CURRENT_READING)
> + return -EINVAL;
> +
> + *possible_states_count = count;
> +
> + return 0;
> +}
> +
> +static int numeric_sensor_has_fault(const struct hp_wmi_numeric_sensor *nsensor)
> +{
> + u32 operational_status = nsensor->operational_status;
> + u32 current_reading = nsensor->current_reading;
> +
> + return operational_status != HP_WMI_STATUS_OK || !current_reading;
> +}
> +
> +/* scale_numeric_sensor - scale sensor reading for hwmon */
> +static long scale_numeric_sensor(const struct hp_wmi_numeric_sensor *nsensor)
> +{
> + u32 current_reading = nsensor->current_reading;
> + s32 unit_modifier = nsensor->unit_modifier;
> + u32 sensor_type = nsensor->sensor_type;
> + u32 base_units = nsensor->base_units;
> + s32 target_modifier;
> + long val;
> +
> + /* Fan readings are in RPM units; others are in milliunits. */
> + target_modifier = sensor_type == HP_WMI_TYPE_AIR_FLOW ? 0 : -3;
> +
> + val = current_reading;
> +
> + for (; unit_modifier < target_modifier; unit_modifier++)
> + val = DIV_ROUND_CLOSEST(val, 10);
> +
> + for (; unit_modifier > target_modifier; unit_modifier--) {
> + if (val > LONG_MAX / 10) {
> + val = LONG_MAX;
> + break;
> + }
> + val *= 10;
> + }
> +
> + if (sensor_type == HP_WMI_TYPE_TEMPERATURE) {
> + switch (base_units) {
> + case HP_WMI_UNITS_DEGREES_F:
> + val -= MILLI * 32;
> + val = val <= LONG_MAX / 5 ?
> + DIV_ROUND_CLOSEST(val * 5, 9) :
> + DIV_ROUND_CLOSEST(val, 9) * 5;
> + break;
> +
> + case HP_WMI_UNITS_DEGREES_K:
> + val = milli_kelvin_to_millicelsius(val);
> + break;
> + }
> + }
> +
> + return val;
> +}
> +
> +/*
> + * classify_numeric_sensor - classify a numeric sensor
> + * @nsensor: pointer to numeric sensor struct
> + *
> + * Returns an enum hp_wmi_type value on success,
> + * or a negative value if the sensor type is unsupported.
> + */
> +static int classify_numeric_sensor(const struct hp_wmi_numeric_sensor *nsensor)
> +{
> + u32 sensor_type = nsensor->sensor_type;
> + u32 base_units = nsensor->base_units;
> +
> + switch (sensor_type) {
> + case HP_WMI_TYPE_TEMPERATURE:
> + if (base_units == HP_WMI_UNITS_DEGREES_C ||
> + base_units == HP_WMI_UNITS_DEGREES_F ||
> + base_units == HP_WMI_UNITS_DEGREES_K)
> + return HP_WMI_TYPE_TEMPERATURE;
> + break;
> +
> + case HP_WMI_TYPE_VOLTAGE:
> + if (base_units == HP_WMI_UNITS_VOLTS)
> + return HP_WMI_TYPE_VOLTAGE;
> + break;
> +
> + case HP_WMI_TYPE_CURRENT:
> + if (base_units == HP_WMI_UNITS_AMPS)
> + return HP_WMI_TYPE_CURRENT;
> + break;
> +
> + case HP_WMI_TYPE_AIR_FLOW:
> + if (base_units == HP_WMI_UNITS_RPM)
> + return HP_WMI_TYPE_AIR_FLOW;
> + break;
> + }
> +
> + return -EINVAL;
> +}
> +
> +static int
> +populate_numeric_sensor_from_wobj(struct device *dev,
> + struct hp_wmi_numeric_sensor *nsensor,
> + const union acpi_object *wobj)
> +{
> + const union acpi_object *element;
> + const char **possible_states;
> + u8 possible_states_count;
> + acpi_object_type type;
> + const char *string;
> + u32 value;
> + int prop;
> + int err;
> +
> + err = check_wobj(wobj, &possible_states_count);
> + if (err)
> + return err;
> +
> + possible_states = devm_kcalloc(dev, possible_states_count,
> + sizeof(*possible_states),
> + GFP_KERNEL);
> + if (!possible_states)
> + return -ENOMEM;
> +
> + element = wobj->package.elements;
> + nsensor->possible_states = possible_states;
> + nsensor->possible_states_count = possible_states_count;
> +
> + for (prop = 0; prop <= HP_WMI_PROPERTY_CURRENT_READING; prop++) {
> + type = hp_wmi_property_map[prop];
> +
> + switch (type) {
> + case ACPI_TYPE_INTEGER:
> + value = element->integer.value;
> + break;
> +
> + case ACPI_TYPE_STRING:
> + string = hp_wmi_strdup(dev, element->string.pointer,
> + element->string.length);
> + if (!string)
> + return -ENOMEM;
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> +
> + element++;
> +
> + switch (prop) {
> + case HP_WMI_PROPERTY_NAME:
> + nsensor->name = string;
> + break;
> +
> + case HP_WMI_PROPERTY_DESCRIPTION:
> + nsensor->description = string;
> + break;
> +
> + case HP_WMI_PROPERTY_SENSOR_TYPE:
> + if (value > HP_WMI_TYPE_AIR_FLOW)
> + return -EINVAL;
> +
> + nsensor->sensor_type = value;
> +
> + /* Skip OtherSensorType if it will be meaningless. */
> + if (value != HP_WMI_TYPE_OTHER) {
> + element++;
> + prop++;
> + }
> +
> + break;
> +
> + case HP_WMI_PROPERTY_OTHER_SENSOR_TYPE:
> + nsensor->other_sensor_type = string;
> + break;
> +
> + case HP_WMI_PROPERTY_OPERATIONAL_STATUS:
> + nsensor->operational_status = value;
> + break;
> +
> + case HP_WMI_PROPERTY_CURRENT_STATE:
> + nsensor->current_state = string;
> + break;
> +
> + case HP_WMI_PROPERTY_POSSIBLE_STATES:
> + *possible_states++ = string;
> + if (--possible_states_count)
> + prop--;
> + break;
> +
> + case HP_WMI_PROPERTY_BASE_UNITS:
> + nsensor->base_units = value;
> + break;
> +
> + case HP_WMI_PROPERTY_UNIT_MODIFIER:
> + /* UnitModifier is signed. */
> + nsensor->unit_modifier = (s32)value;
> + break;
> +
> + case HP_WMI_PROPERTY_CURRENT_READING:
> + nsensor->current_reading = value;
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> + }
> +
> + return 0;
> +}
> +
> +/* update_numeric_sensor_from_wobj - update fungible sensor properties */
> +static void
> +update_numeric_sensor_from_wobj(struct device *dev,
> + struct hp_wmi_numeric_sensor *nsensor,
> + const union acpi_object *wobj)
> +{
> + const union acpi_object *elements;
> + const union acpi_object *element;
> + const char *string;
> + u32 length;
> + u8 offset;
> +
> + elements = wobj->package.elements;
> +
> + element = &elements[HP_WMI_PROPERTY_OPERATIONAL_STATUS];
> + nsensor->operational_status = element->integer.value;
> +
> + element = &elements[HP_WMI_PROPERTY_CURRENT_STATE];
> + string = element->string.pointer;
> +
> + if (strcmp(string, nsensor->current_state)) {
> + length = element->string.length;
> + devm_kfree(dev, nsensor->current_state);
> + nsensor->current_state = hp_wmi_strdup(dev, string, length);
> + }
> +
> + /* Offset reads into the elements array after PossibleStates[0]. */
> + offset = nsensor->possible_states_count - 1;
> +
> + element = &elements[HP_WMI_PROPERTY_UNIT_MODIFIER + offset];
> + nsensor->unit_modifier = (s32)element->integer.value;
> +
> + element = &elements[HP_WMI_PROPERTY_CURRENT_READING + offset];
> + nsensor->current_reading = element->integer.value;
> +}
> +
> +/*
> + * interpret_info - interpret sensor for hwmon
> + * @info: pointer to sensor info struct
> + *
> + * Should be called after the numeric sensor member has been updated.
> + */
> +static void interpret_info(struct hp_wmi_info *info)
> +{
> + const struct hp_wmi_numeric_sensor *nsensor = &info->nsensor;
> +
> + info->cached_val = scale_numeric_sensor(nsensor);
> + info->last_updated = jiffies;
> +}
> +
> +/*
> + * hp_wmi_update_info - poll WMI to update sensor info
> + * @state: pointer to driver state
> + * @info: pointer to sensor info struct
> + *
> + * Returns 0 on success, or a negative error code on error.
> + */
> +static int hp_wmi_update_info(struct hp_wmi_sensors *state,
> + struct hp_wmi_info *info)
> +{
> + struct hp_wmi_numeric_sensor *nsensor = &info->nsensor;
> + struct device *dev = &state->wdev->dev;
> + const union acpi_object *wobj;
> + u8 instance = info->instance;
> + int ret = 0;
> +
> + if (time_after(jiffies, info->last_updated + HZ)) {
> + mutex_lock(&state->lock);
> +
> + wobj = hp_wmi_get_wobj(state, instance);
> + if (!wobj) {
> + ret = -EIO;
> + goto out_free_wobj;
> + }
> +
> + update_numeric_sensor_from_wobj(dev, nsensor, wobj);
> +
> + interpret_info(info);
> +
> +out_free_wobj:
> + kfree(wobj);
> +
> + mutex_unlock(&state->lock);
> + }
> +
> + return ret;
> +}
> +
> +#if CONFIG_DEBUG_FS
> +
> +static int basic_string_show(struct seq_file *seqf, void *ignored)
> +{
> + const char *str = seqf->private;
> +
> + seq_printf(seqf, "%s\n", str);
> +
> + return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(basic_string);
> +
> +static int fungible_show(struct seq_file *seqf, enum hp_wmi_property prop)
> +{
> + struct hp_wmi_numeric_sensor *nsensor;
> + struct hp_wmi_sensors *state;
> + struct hp_wmi_info *info;
> + int err;
> +
> + switch (prop) {
> + case HP_WMI_PROPERTY_OPERATIONAL_STATUS:
> + nsensor = container_of(seqf->private,
> + struct hp_wmi_numeric_sensor,
> + operational_status);
> + break;
> +
> + case HP_WMI_PROPERTY_CURRENT_STATE:
> + nsensor = container_of(seqf->private,
> + struct hp_wmi_numeric_sensor,
> + current_state);
> + break;
> +
> + case HP_WMI_PROPERTY_UNIT_MODIFIER:
> + nsensor = container_of(seqf->private,
> + struct hp_wmi_numeric_sensor,
> + unit_modifier);
> + break;
> +
> + case HP_WMI_PROPERTY_CURRENT_READING:
> + nsensor = container_of(seqf->private,
> + struct hp_wmi_numeric_sensor,
> + current_reading);
> + break;
> +
> + default:
> + return -EOPNOTSUPP;
> + }
> +
> + info = container_of(nsensor, struct hp_wmi_info, nsensor);
> + state = container_of(info, struct hp_wmi_sensors, info[info->instance]);
> +
> + err = hp_wmi_update_info(state, info);
> + if (err)
> + return err;
> +
> + switch (prop) {
> + case HP_WMI_PROPERTY_OPERATIONAL_STATUS:
> + seq_printf(seqf, "%u\n", nsensor->operational_status);
> + break;
> +
> + case HP_WMI_PROPERTY_CURRENT_STATE:
> + seq_printf(seqf, "%s\n", nsensor->current_state);
> + break;
> +
> + case HP_WMI_PROPERTY_UNIT_MODIFIER:
> + seq_printf(seqf, "%d\n", nsensor->unit_modifier);
> + break;
> +
> + case HP_WMI_PROPERTY_CURRENT_READING:
> + seq_printf(seqf, "%u\n", nsensor->current_reading);
> + break;
> +
> + default:
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static int operational_status_show(struct seq_file *seqf, void *ignored)
> +{
> + return fungible_show(seqf, HP_WMI_PROPERTY_OPERATIONAL_STATUS);
> +}
> +DEFINE_SHOW_ATTRIBUTE(operational_status);
> +
> +static int current_state_show(struct seq_file *seqf, void *ignored)
> +{
> + return fungible_show(seqf, HP_WMI_PROPERTY_CURRENT_STATE);
> +}
> +DEFINE_SHOW_ATTRIBUTE(current_state);
> +
> +static int possible_states_show(struct seq_file *seqf, void *ignored)
> +{
> + struct hp_wmi_numeric_sensor *nsensor = seqf->private;
> + u8 i;
> +
> + for (i = 0; i < nsensor->possible_states_count; i++)
> + seq_printf(seqf, "%s\n", nsensor->possible_states[i]);
> +
> + return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(possible_states);
> +
> +static int unit_modifier_show(struct seq_file *seqf, void *ignored)
> +{
> + return fungible_show(seqf, HP_WMI_PROPERTY_UNIT_MODIFIER);
> +}
> +DEFINE_SHOW_ATTRIBUTE(unit_modifier);
> +
> +static int current_reading_show(struct seq_file *seqf, void *ignored)
> +{
> + return fungible_show(seqf, HP_WMI_PROPERTY_CURRENT_READING);
> +}
> +DEFINE_SHOW_ATTRIBUTE(current_reading);
> +
> +/* hp_wmi_devm_debugfs_remove - devm callback for debugfs cleanup */
> +static void hp_wmi_devm_debugfs_remove(void *res)
> +{
> + debugfs_remove_recursive(res);
> +}
> +
> +/* hp_wmi_debugfs_init - create and populate debugfs directory tree */
> +static void hp_wmi_debugfs_init(struct hp_wmi_sensors *state)
> +{
> + struct device *dev = &state->wdev->dev;
> + struct hp_wmi_info *info = state->info;
> + struct hp_wmi_numeric_sensor *nsensor;
> + char buf[HP_WMI_MAX_STR_SIZE];
> + struct dentry *dir;
> + int err;
> + u8 i;
> +
> + /* dev_name() gives a not-very-friendly GUID for WMI devices. */
> + scnprintf(buf, sizeof(buf), "%s-%u", "hp-wmi-sensors", dev->id);
> +
> + state->debugfs = debugfs_create_dir(buf, NULL);
> + if (IS_ERR(state->debugfs))
> + return;
> +
> + err = devm_add_action(dev, hp_wmi_devm_debugfs_remove, state->debugfs);
> + if (err) {
> + debugfs_remove(state->debugfs);
> + return;
> + }
> +
> + for (i = 0; i < state->count; i++, info++) {
> + nsensor = &info->nsensor;
> +
> + scnprintf(buf, sizeof(buf), "%u", i);
> + dir = debugfs_create_dir(buf, state->debugfs);
> +
> + debugfs_create_file("name", 0444, dir,
> + (void *)nsensor->name,
> + &basic_string_fops);
> +
> + debugfs_create_file("description", 0444, dir,
> + (void *)nsensor->description,
> + &basic_string_fops);
> +
> + debugfs_create_u32("sensor_type", 0444, dir,
> + &nsensor->sensor_type);
> +
> + debugfs_create_file("other_sensor_type", 0444, dir,
> + (void *)nsensor->other_sensor_type,
> + &basic_string_fops);
> +
> + debugfs_create_file("operational_status", 0444, dir,
> + &nsensor->operational_status,
> + &operational_status_fops);
> +
> + debugfs_create_file("current_state", 0444, dir,
> + (void *)&nsensor->current_state,
> + ¤t_state_fops);
> +
> + debugfs_create_file("possible_states", 0444, dir,
> + nsensor, &possible_states_fops);
> +
> + debugfs_create_u32("base_units", 0444, dir,
> + &nsensor->base_units);
> +
> + debugfs_create_file("unit_modifier", 0444, dir,
> + &nsensor->unit_modifier,
> + &unit_modifier_fops);
> +
> + debugfs_create_file("current_reading", 0444, dir,
> + &nsensor->current_reading,
> + ¤t_reading_fops);
> + }
> +}
> +
> +#else
> +
> +static void hp_wmi_debugfs_init(struct hp_wmi_sensors *state)
> +{
> +}
> +
> +#endif
> +
> +static umode_t hp_wmi_hwmon_is_visible(const void *drvdata,
> + enum hwmon_sensor_types type,
> + u32 attr, int channel)
> +{
> + const struct hp_wmi_sensors *state = drvdata;
> +
> + if (!state->info_map[type] || !state->info_map[type][channel])
> + return 0;
> +
> + return 0444;
> +}
> +
> +static int hp_wmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long *val)
> +{
> + struct hp_wmi_sensors *state = dev_get_drvdata(dev);
> + const struct hp_wmi_numeric_sensor *nsensor;
> + struct hp_wmi_info *info;
> + int err;
> +
> + info = state->info_map[type][channel];
> + nsensor = &info->nsensor;
> +
> + err = hp_wmi_update_info(state, info);
> + if (err)
> + return err;
> +
> + else if ((type == hwmon_temp && attr == hwmon_temp_fault) ||
> + (type == hwmon_fan && attr == hwmon_fan_fault))
> + *val = numeric_sensor_has_fault(nsensor);
> +
> + else
> + *val = info->cached_val;
> +
> + return 0;
> +}
> +
> +static int hp_wmi_hwmon_read_string(struct device *dev,
> + enum hwmon_sensor_types type, u32 attr,
> + int channel, const char **str)
> +{
> + const struct hp_wmi_sensors *state = dev_get_drvdata(dev);
> + const struct hp_wmi_info *info;
> +
> + info = state->info_map[type][channel];
> + *str = info->nsensor.name;
> +
> + return 0;
> +}
> +
> +static int add_channel_info(struct device *dev,
> + struct hwmon_channel_info *channel_info,
> + u8 count, enum hwmon_sensor_types type)
> +{
> + u32 attr = hp_wmi_hwmon_attributes[type];
> + u32 *config;
> +
> + config = devm_kcalloc(dev, count + 1, sizeof(*config), GFP_KERNEL);
> + if (!config)
> + return -ENOMEM;
> +
> + channel_info->type = type;
> + channel_info->config = config;
> + memset32(config, attr, count);
> +
> + return 0;
> +}
> +
> +static const struct hwmon_ops hp_wmi_hwmon_ops = {
> + .is_visible = hp_wmi_hwmon_is_visible,
> + .read = hp_wmi_hwmon_read,
> + .read_string = hp_wmi_hwmon_read_string,
> +};
> +
> +static struct hwmon_chip_info hp_wmi_chip_info = {
> + .ops = &hp_wmi_hwmon_ops,
> + .info = NULL,
> +};
> +
> +static int hp_wmi_sensors_init(struct hp_wmi_sensors *state)
> +{
> + struct hp_wmi_info *active_info[HP_WMI_MAX_INSTANCES];
> + const struct hwmon_channel_info **ptr_channel_info;
> + struct hwmon_channel_info *channel_info;
> + struct device *dev = &state->wdev->dev;
> + struct hp_wmi_info *info = state->info;
> + struct hp_wmi_numeric_sensor *nsensor;
> + u8 channel_count[hwmon_max] = {};
> + enum hwmon_sensor_types type;
> + union acpi_object *wobj;
> + struct device *hwdev;
> + u8 type_count = 0;
> + u8 channel;
> + int wtype;
> + int err;
> + u8 i;
> +
> + for (i = 0, channel = 0; i < HP_WMI_MAX_INSTANCES; i++, info++) {
> + wobj = hp_wmi_get_wobj(state, i);
> + if (!wobj)
> + break;
> +
> + info->instance = i;
> + nsensor = &info->nsensor;
> +
> + err = populate_numeric_sensor_from_wobj(dev, nsensor, wobj);
> + if (err)
> + goto out_free_wobj;
> +
> + if (numeric_sensor_has_fault(nsensor))
> + goto out_free_wobj;
> +
Hi,
is it guaranteed that faulty sensors wont become operational later?
Also filtering out such sensors would make the support for the hwmon_temp_fault and
hwmon_fan_fault attributes meaningless.
> + wtype = classify_numeric_sensor(nsensor);
> + if (wtype < 0)
> + goto out_free_wobj;
> +
> + type = hp_wmi_hwmon_type_map[wtype];
> + if (!channel_count[type])
> + type_count++;
> + channel_count[type]++;
> +
> + info->is_active = true;
> + info->type = type;
> +
> + interpret_info(info);
> +
> + active_info[channel++] = info;
> +
> +out_free_wobj:
> + kfree(wobj);
> +
> + if (err)
> + return err;
> + }
> +
> + dev_dbg(dev, "Found %u sensors (%u active, %u types)\n",
> + i, channel, type_count);
> +
> + state->count = i;
> + if (!state->count)
> + return -ENODATA;
> +
> + hp_wmi_debugfs_init(state);
> +
> + if (!channel)
> + return 0; /* Not an error, but debugfs only. */
> +
> + if (channel_count[hwmon_temp]) {
> + channel_count[hwmon_chip] = 1;
> + type_count++;
> + }
> +
> + memcpy(state->channel_count, channel_count, sizeof(channel_count));
> +
> + channel_info = devm_kcalloc(dev, type_count,
> + sizeof(*channel_info),
> + GFP_KERNEL);
> + if (!channel_info)
> + return -ENOMEM;
> +
> + ptr_channel_info = devm_kcalloc(dev, type_count + 1,
> + sizeof(*ptr_channel_info),
> + GFP_KERNEL);
> + if (!ptr_channel_info)
> + return -ENOMEM;
> +
> + hp_wmi_chip_info.info = ptr_channel_info;
> +
> + for (type = hwmon_chip; type < hwmon_max; type++) {
> + if (!channel_count[type])
> + continue;
> +
> + err = add_channel_info(dev, channel_info,
> + channel_count[type], type);
> + if (err)
> + return err;
> +
> + *ptr_channel_info++ = channel_info++;
> +
> + state->info_map[type] = devm_kcalloc(dev, channel_count[type],
> + sizeof(*state->info_map),
> + GFP_KERNEL);
> + if (!state->info_map[type])
> + return -ENOMEM;
> + }
> +
> + while (channel > 0) {
> + type = active_info[--channel]->type;
> + i = --channel_count[type];
> + state->info_map[type][i] = active_info[channel];
> + }
> +
> + hwdev = devm_hwmon_device_register_with_info(dev, "hp_wmi_sensors",
> + state, &hp_wmi_chip_info,
> + NULL);
> + return PTR_ERR_OR_ZERO(hwdev);
> +}
> +
> +static int hp_wmi_sensors_probe(struct wmi_device *wdev, const void *context)
> +{
> + struct device *dev = &wdev->dev;
> + struct hp_wmi_sensors *state;
> + int err;
> +
> + /* Sanity check. */
> + if (!wmi_has_guid(HP_WMI_NUMERIC_SENSOR_GUID) ||
> + !wmi_has_guid(HP_WMI_BIOS_GUID)) {
> + err = -ENODEV;
> + goto out_err;
> + }
> +
The sanity check for HP_WMI_NUMERIC_SENSOR_GUID is unnecessary, the WMI driver core already makes sure that your driver
is only matched with WMI devices containing HP_WMI_NUMERIC_SENSOR_GUID.
As for the sanity check regarding HP_WMI_BIOS_GUID: this WMI GUID is not used inside the driver. Since WMI GUIDs are expected
to be unique, checking for HP_WMI_BIOS_GUID (which AFAIK is used by the HP-BIOSCFG driver) without intending to use it is
meaningless.
Armin Wolf
> + state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
> + if (!state) {
> + err = -ENOMEM;
> + goto out_err;
> + }
> +
> + state->wdev = wdev;
> +
> + mutex_init(&state->lock);
> +
> + dev_set_drvdata(dev, state);
> +
> + err = hp_wmi_sensors_init(state);
> +
> +out_err:
> + return err;
> +}
> +
> +static const struct wmi_device_id hp_wmi_sensors_id_table[] = {
> + { HP_WMI_NUMERIC_SENSOR_GUID, NULL },
> + {},
> +};
> +
> +static struct wmi_driver hp_wmi_sensors_driver = {
> + .driver = { .name = "hp-wmi-sensors" },
> + .id_table = hp_wmi_sensors_id_table,
> + .probe = hp_wmi_sensors_probe,
> +};
> +module_wmi_driver(hp_wmi_sensors_driver);
> +
> +MODULE_AUTHOR("James Seo <james@...iv.tech>");
> +MODULE_DESCRIPTION("HP WMI Sensors driver");
> +MODULE_LICENSE("GPL");
>
> base-commit: 76f598ba7d8e2bfb4855b5298caedd5af0c374a8
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