wmi/devices/dell-wmi-ddv.rst

1 .. SPDX-License-Identifier: GPL-2.0-or-later
4 Dell DDV WMI interface driver (dell-wmi-ddv)
10 Many Dell notebooks made after ~2020 support a WMI-based interface for
11 retrieving various system data like battery temperature, ePPID, diagnostic data
15 so it was called `DDV`. Currently the ``dell-wmi-ddv`` driver supports
21              trial-and-error, please keep that in mind.
27 including batteries. It has a form similar to `CC-PPPPPP-MMMMM-YMD-SSSS-FFF`
52 …), Locale("MS\\0x409"), Description("WMI Function"), guid("{8A42EA14-4F2A-FD45-6422-0087F7A7E608}"…
57 …[WmiMethodId(1), Implemented, read, write, Description("Return Battery Design Capacity.")] void Ba…
58 …[WmiMethodId(2), Implemented, read, write, Description("Return Battery Full Charge Capacity.")] vo…
59 …[WmiMethodId(3), Implemented, read, write, Description("Return Battery Manufacture Name.")] void B…
60 …[WmiMethodId(4), Implemented, read, write, Description("Return Battery Manufacture Date.")] void B…
61 …[WmiMethodId(5), Implemented, read, write, Description("Return Battery Serial Number.")] void Batt…
62 …[WmiMethodId(6), Implemented, read, write, Description("Return Battery Chemistry Value.")] void Ba…
63 …[WmiMethodId(7), Implemented, read, write, Description("Return Battery Temperature.")] void Batter…
64 …[WmiMethodId(8), Implemented, read, write, Description("Return Battery Current.")] void BatteryCur…
65 …[WmiMethodId(9), Implemented, read, write, Description("Return Battery Voltage.")] void BatteryVol…
66 …[WmiMethodId(10), Implemented, read, write, Description("Return Battery Manufacture Access(MA code…
67 …[WmiMethodId(11), Implemented, read, write, Description("Return Battery Relative State-Of-Charge."…
68 …[WmiMethodId(12), Implemented, read, write, Description("Return Battery Cycle Count")] void Batter…
69 …[WmiMethodId(13), Implemented, read, write, Description("Return Battery ePPID")] void BatteryePPID…
70 …[WmiMethodId(14), Implemented, read, write, Description("Return Battery Raw Analytics Start")] voi…
71 …[WmiMethodId(15), Implemented, read, write, Description("Return Battery Raw Analytics")] void Batt…
72 …[WmiMethodId(16), Implemented, read, write, Description("Return Battery Design Voltage.")] void Ba…
73 …[WmiMethodId(17), Implemented, read, write, Description("Return Battery Raw Analytics A Block")] v…
79 Each WMI method takes an ACPI buffer containing a 32-bit index as input argument,
80 with the first 8 bit being used to specify the battery when using battery-related
92 The data format of many battery-related methods seems to be based on the
93 `Smart Battery Data Specification`, so unknown battery-related methods are
97 -------------------------------------
99 Returns the design capacity of the battery in mAh as an u16.
102 ------------------------------
104 Returns the full charge capacity of the battery in mAh as an u16.
107 -----------------------------------
109 Returns the manufacture name of the battery as an ASCII string.
112 -----------------------------------
114 Returns the manufacture date of the battery as an u16.
117 - bits 0 to 4 contain the manufacture day.
118 - bits 5 to 8 contain the manufacture month.
119 - bits 9 to 15 contain the manufacture year biased by 1980.
125 --------------------------------
127 Returns the serial number of the battery as an u16.
130 ----------------------------------
132 Returns the chemistry of the battery as an ASCII string.
135 - "Li-I" for Li-Ion
138 -------------------------------
140 Returns the temperature of the battery in tenth degree kelvin as an u16.
143 ---------------------------
145 Returns the current flow of the battery in mA as an s16.
149 ---------------------------
151 Returns the voltage flow of the battery in mV as an u16.
154 -------------------------------------
156 Returns a manufacture-defined value as an u16.
159 -----------------------------------------
161 Returns the capacity of the battery in percent as an u16.
164 ------------------------------
166 Returns the cycle count of the battery as an u16.
169 -------------------------
171 Returns the ePPID of the battery as an ASCII string.
174 --------------------------------------
176 Performs an analysis of the battery and returns a status code:
178 - ``0x0``: Success
179 - ``0x1``: Interface not supported
180 - ``0xfffffffe``: Error/Timeout
186 ---------------------------------
191 - a block number starting with 0 (u8)
192 - 31 bytes of unknown data
198 ---------------------------------
200 Returns the design voltage of the battery in mV as an u16.
203 ---------------------------------------
214 --------------------------
219 ---------------------------------
225 - fan type (u8)
226 - fan speed in RPM (little endian u16)
229 -------------------------------------
235 - thermal type (u8)
236 - current temperature (s8)
237 - min. temperature (s8)
238 - max. temperature (s8)
239 - unknown field (u8)
244 ACPI battery matching algorithm
250 Basically for each new ACPI battery, the serial numbers of the batteries behind
251 indices 1 till 3 are compared with the serial number of the ACPI battery.
252 Since the serial number of the ACPI battery can either be encoded as a normal
257 with an actual battery, or that the associated battery is not present.
259 Some machines like the Dell Inspiron 3505 only support a single battery and thus
260 ignore the battery index. Because of this the driver depends on the ACPI battery
264    The ACPI battery matching algorithm currently used inside the driver is
271 Reverse-Engineering the DDV WMI interface
278    flow with other ACPI methods (_BIX or _BIF for battery related methods
280 5. Use the built-in UEFI diagnostics to view sensor types/values for fan/thermal
287 1. Load the ``dell-wmi-ddv`` driver, use the ``force`` module param
290 3. Compare the data with the built-in UEFI diagnostics.
295 to the ``dell-wmi-ddv`` driver.
297 See Documentation/admin-guide/reporting-issues.rst for further information.