1# events.json 2 3This file defines the events that dictate how fan control operates. Each event 4can contain groups, triggers, and actions. 5 6Actions are where fan targets are calculated and set, among other things. 7Triggers specify when an action should run. Groups specify which D-Bus objects 8the triggers and actions should operate on. 9 10Some actions have modifiers, which help calculate a value. 11 12- [Groups](#groups) 13- [Triggers](#triggers) 14- [Actions](#actions) 15- [Modifiers](#modifiers) 16 17## Example 18 19``` 20[ 21 { 22 "name": "fan(s) missing", 23 "groups": [ 24 { 25 "name": "fan inventory", 26 "interface": "xyz.openbmc_project.Inventory.Item", 27 "property": { "name": "Present" } 28 } 29 ], 30 "triggers": [ 31 { 32 "class": "init", 33 "method": "get_properties" 34 }, 35 { 36 "class": "signal", 37 "signal": "properties_changed" 38 } 39 ], 40 "actions": [ 41 { 42 "name": "count_state_before_target", 43 "count": 1, 44 "state": false, 45 "target": 15000 46 } 47 ] 48 } 49] 50``` 51 52The above event is an example of a method to set the fan target to 15000 when 53one or more fans is missing. The basic behavior with this config is: 54 55The trigger `init.get_properties` will, on fan control startup, read the Present 56property on the `xyz.openbmc_project.Inventory.Item` interface from every D-Bus 57object in the 'fan inventory' group, update those values in the object cache, 58and then call the `count_state_before_target` action. 59 60The trigger `signal.properties_changed` will watch for changes on the Present 61property on each D-Bus object in the group, update the new value in the object 62cache, and call the `count_state_before_target` action when the value changes. 63 64The `count_state_before_target` action will look at the object cache value of 65the Present property on each member of the group and set the fan target hold to 6615000 when one or more of them is false. Otherwise, it will clear its fan target 67hold. 68 69## Groups 70 71``` 72"groups": [ 73 { 74 "name": "<name>", 75 "interface": "<interface>", 76 "property": { "name": "<name>" } 77 } 78 ... 79] 80``` 81 82### name 83 84The name of a group that must be also be defined in [groups.json](groups.md). 85 86### interface 87 88The actions and triggers defined with this group will look at this D-Bus 89interface on the members of this group. 90 91### property: name 92 93The actions and triggers defined with this group will look at this D-Bus 94property on the members of this group. 95 96## Triggers 97 98There are several classes of triggers, and the JSON configuration is different 99for each. 100 101### init 102 103Init triggers run when fan control events are enabled on fan control startup. 104After invoking the configured method, any actions configured for this trigger 105will run. 106 107``` 108{ 109 "class": "init", 110 "method": "<method>" 111} 112``` 113 114#### methods 115 1161. `get_properties` - Read the property configured for the group from every 117 member of the group, and store it in fan control's object cache. 118 1192. `name_has_owner` - Populates the service owned state from D-Bus for each 120 group member in fan control's D-Bus service cache map. 121 122### signal 123 124Signal triggers subscribe to certain D-Bus signals for each member of its 125configured group. After handling the signal, any configured actions are run. 126 127``` 128{ 129 "class": "signal", 130 "signal": "<signal>" 131} 132``` 133 134#### signal types 135 1361. `properties_changed` - Subscribes to the PropertiesChanged signal for the 137 D-Bus interface and property specified in the group definition for each group 138 member. When the signal occurs, the new property value will be added to or 139 updated in the object cache. 140 1412. `interfaces_added` - Subscribes to the InterfacesAdded signal for the D-Bus 142 interface specified in the group definition for each group member. When the 143 signal occurs, the interface and its properties will be added to the object 144 cache. 145 1463. `interfaces_removed` - Subscribes to the InterfacesRemoved signal for the 147 D-Bus interface specified in the group definition for each group member. When 148 the signal occurs, the interface and properties will be removed from the 149 object cache. 150 1514. `name_owner_changed` - Subscribes to the NameOwnerChanged signal for the 152 services that host the D-bus interface specified in the group definition for 153 each group member. When the signal occurs, the service owned state will be 154 updated in the service cache map. 155 1565. `member` - Subscribes to the signal listed on each group member. No caches 157 are updated when the signal occurs. 158 159### timer 160 161Timer triggers run actions after the configured type of timer expires. 162 163``` 164{ 165 "class": "timer", 166 "type": "<type>", 167 "interval": "<interval>", 168 "preload_groups": "<true/false>" 169} 170``` 171 172#### type 173 1741. `oneshot` - Starts a timer that runs once. 175 1762. `repeating` - Starts a repeating timer. 177 178#### interval 179 180The timer length in microseconds 181 182#### preload_groups 183 184Optional, if set to true, will update the D-Bus properties from the configured 185groups in the object cache after the timer expires but before any actions run. 186 187### parameter 188 189Parameter triggers run actions after a parameter changes. 190 191``` 192{ 193 "class": "parameter", 194 "parameter": "<parameter>" 195} 196``` 197 198#### parameter 199 200The parameter value to watch. 201 202### poweron 203 204PowerOn triggers run when the power turns on. Functionally, they behave like an 205init trigger. 206 207``` 208{ 209 "class": "poweron", 210 "method": "<method>" 211} 212``` 213 214#### method 215 216The methods are the same as with the init trigger. 217 218### poweroff 219 220PowerOff triggers run when the power turns off. Functionally, they behave like 221an init trigger. 222 223``` 224{ 225 "class": "poweroff", 226 "method": "<method>" 227} 228``` 229 230#### method 231 232The methods are the same as with the init trigger. 233 234## Actions 235 236Actions can either operate on the groups listed with the event, or on the groups 237listed within the action's JSON config. 238 239Most actions set fan targets or floors. This can be done by requesting a target 240value explicitly, or by requesting an increase or decrease delta. Targets and 241floors can also be set with a hold, meaning another action can't set a 242floor/target below the one that is held. 243 244Some actions set or read a key/value pair called a parameter. These can be 245created, updated, and deleted as necessary. For example, one action may 246calculate and set a `floor_index` parameter, and another action may then read 247that parameter to help choose a fan floor. 248 249The available actions are: 250 251- [set_net_increase_target](#set_net_increase_target) 252- [set_net_decrease_target](#set_net_decrease_target) 253- [count_state_floor](#count_state_floor) 254- [count_state_before_target](#count_state_before_target) 255- [default_floor_on_missing_owner](#default_floor_on_missing_owner) 256- [mapped_floor](#mapped_floor) 257- [set_target_on_missing_owner](#set_target_on_missing_owner) 258- [override_fan_target](#override_fan_target) 259- [pcie_card_floors](#pcie_card_floors) 260- [set_request_target_base_with_max](#set_request_target_base_with_max) 261- [set_parameter_from_group_max](#set_parameter_from_group_max) 262- [target_from_group_max](#target_from_group_max) 263- [call_actions_based_on_timer](#call_actions_based_on_timer) 264- [get_managed_objects](#get_managed_objects) 265 266### set_net_increase_target 267 268Calculates the net target increase to be requested based on the value of each 269property given within a group. The net target increase is based on the maximum 270difference between the `delta` JSON value and all of the properties of the 271group. The final result is the increase change that's requested to the current 272target of a zone. 273 274The group values can be compared to either a value hardcoded in the JSON, or a 275parameter value. 276 277``` 278{ 279 "name": "set_net_increase_target", 280 "groups": [{ 281 "name": "pcie temps", 282 "interface": "xyz.openbmc_project.Sensor.Value", 283 "property": { "name": "Value" } 284 }], 285 "state": 70.0, 286 "delta": 255 287} 288``` 289 290The above config uses a hardcoded state value: 291 2921. For each member of the 'pcie temps' group: 293 294- Read its 'Value' D-Bus property. 295- If that property value is greater than the 'state' value of 70.0: 296- Subtracts 70.0 from the property value. 297- Multiplies that difference by the 'delta' value of 255. 298 2992. Requests an increase of the largest calculated delta value, if there is one. 300 301``` 302{ 303 "name": "set_net_increase_target", 304 "groups": [{ 305 "name": "proc0 core temps", 306 "interface": "xyz.openbmc_project.Sensor.Value", 307 "property": { "name": "Value" } 308 }], 309 "state_parameter_name": "proc_0_core_dvfs_increase_temp", 310 "delta": 300 311} 312``` 313 314The above config uses a parameter as the state value: 315 3161. For each member of the 'proc 0 core temps' group: 317 318- Read its 'Value' D-Bus property. 319- If that property value is greater than the value of the parameter listed in 320 the 'state_parameter_name' field, in this case 321 'proc_0_core_dvfs_increase_temp': 322- Subtracts that parameter value from the property value. 323- Multiplies that difference by the 'delta' value of 300. 324 3252. Requests an increase of the largest calculated delta value, if there is one. 326 327### set_net_decrease_target 328 329Calculates the net target decrease to be requested based on the value of each 330property given within a group. The net target decrease is based on the minimum 331difference between the `delta` JSON value and all properties in the group. The 332final result is the decrease change that's requested to the current target of a 333zone. 334 335The group values can be compared to either a value hardcoded in the JSON, or a 336parameter value. 337 338``` 339{ 340 "name": "set_net_decrease_target", 341 "groups": [{ 342 "name": "pcie temps", 343 "interface": "xyz.openbmc_project.Sensor.Value", 344 "property": { "name": "Value" } 345 }], 346 "state": 65.0, 347 "delta": 80 348} 349 350``` 351 352The above config uses a hardcoded state value: 353 3541. For each member of the 'pcie temps' group: 355 356- Read its 'Value' D-Bus property. 357- If that property value is less than the 'state' value of 65.0: 358- Subtracts the property value from 65.0. 359- Multiplies that difference by the 'delta' value of 80. 360 3612. Requests a decrease of the smallest calculated delta value, if there is one. 362 363``` 364{ 365 "name": "set_net_decrease_target", 366 "groups": [{ 367 "name": "proc 0 core temps", 368 "interface": "xyz.openbmc_project.Sensor.Value", 369 "property": { "name": "Value" } 370 }], 371 "state_parameter_name": "proc_0_core_dvfs_decrease_temp", 372 "delta": 50 373} 374``` 375 376The above config uses a parameter as the state value: 377 3781. For each member of the 'proc 0 core temps' group: 379 380- Read its 'Value' D-Bus property. 381- If that property value is less than the value of the parameter listed the 382 'state_parameter_name' field, in this case 'proc_0_core_dvfs_decrease_temp': 383- Subtracts the property value from the parameter value. 384- Multiplies that difference by the 'delta' value of 50. 385 3862. Requests a decrease of the smallest calculated delta value, if there is one. 387 388### count_state_floor 389 390Sets the fans to a configured floor when a number of members within the group 391are at a configured state. Once the number of members at the given state falls 392below the configured count, the floor hold is released. 393 394``` 395{ 396 "name": "count_state_floor", 397 "count": 2, 398 "state": false, 399 "floor": 18000 400} 401``` 402 403The above config reads the configured D-Bus property on each group member 404configured for the action. If two or more members have a property value of 405false, a floor hold will be requested with a value of 18000. Otherwise, the 406floor hold will be released (if it was previously requested). 407 408### count_state_before_target 409 410Sets the fans to a configured target when a number of members within the group 411are at a configured state. Once the number of members at the given state falls 412below the configured count, active fan target changes are allowed. 413 414``` 415{ 416 "name": "count_state_before_target", 417 "count": 1, 418 "state": false, 419 "target": 18000 420} 421``` 422 423The above config reads the configured D-Bus property on each group member 424configured for the action. If one or more members have a property value of 425false, a target hold will be requested with a value of 18000. Otherwise, the 426hold will be released (if it was previously requested). 427 428### default_floor_on_missing_owner 429 430Sets the fan floor to the defined zone's default fan floor when a service 431associated to a given group has terminated. Once all services are functional and 432providing the sensors, the fan floor is allowed to be set normally again. 433 434There is no additional JSON config for this action. 435 436### mapped_floor 437 438This action can be used to set a floor value based on 2 or more groups having 439values within certain ranges, where the key group chooses the set of tables in 440which to check the remaining group values. 441 442``` 443{ 444 "name": "mapped_floor", 445 "key_group": "ambient temp", 446 "default_floor": 5555, 447 "fan_floors": [ 448 { 449 "key": 25, 450 "default_floor": 4444, 451 "floor_offset_parameter": "ambient_25_altitude_offset", 452 "floors": [ 453 { 454 "parameter": "pcie_floor_index", 455 "floors": [ 456 { "value": 1, "floor": 2000 }, 457 { "value": 2, "floor": 3000 }, 458 { "value": 3, "floor": 4000 }, 459 { "value": 4, "floor": 5000 }, 460 { "value": 5, "floor": 6000 } 461 ] 462 }, 463 { 464 "group": "power save", 465 "floors": [ 466 { "value": true, "floor": 1000 } 467 ] 468 } 469 ] 470 } 471} 472``` 473 474The above config will use the maximum value of the 'ambient temp' group as the 475key into the 'fan_floors' tables. There is one of those tables listed, and it 476will be used when the key group has a max value of less than 25. 477 478It will then traverse the contained floors arrays, keeping track of the highest 479valid floor value it finds. If it doesn't find any valid floor values, it will 480use the `default_floor` value of 4444, though that value is optional. 481 482If no valid tables were found given the key value, the `default_floor` value of 4835555 would be used, though that is optional and if not supplied the code would 484default to the default floor of the zone. 485 486At the end of the analysis, a floor hold will be set with the final floor value. 487 488### set_target_on_missing_owner 489 490Sets the fans to a configured target when any service owner associated to the 491group is missing. Once all services are functional and providing all the group 492data again, active fan target changes are allowed. 493 494``` 495{ 496 "name": "set_target_on_missing_owner", 497 "groups": [{ 498 "name": "fan inventory", 499 "interface": "xyz.openbmc_project.Inventory.Item", 500 "property": { "name": "Present" } 501 }], 502 "target": 18000 503} 504``` 505 506The above config will set a target hold of 18000 when the service associated 507with the 'fan inventory' group is lost. 508 509### override_fan_target 510 511This action locks fans at configured targets when the configured `count` amount 512of fans meet criterion for the particular condition. A locked fan maintains its 513override target until unlocked (or locked at a higher target). Upon unlocking, 514it will either revert to temperature control or activate the next-highest target 515remaining in its list of locks. 516 517``` 518{ 519 "name": "override_fan_target", 520 "count": 1, 521 "state": false, 522 "fans": [ "fan0", "fan1", "fan2", "fan3" ], 523 "target": 10000 524} 525``` 526 527The above config will lock all fans in the fans array at a target of 10000 when 528one or more members in its configured group have a group property value of 529false. 530 531This could be used for example, to lock the rotors of a multirotor fan to a high 532target when one of its rotors has a functional property equal to false. 533 534### pcie_card_floors 535 536Sets the `pcie_floor_index` parameter based on the current configuration of 537plugged and powered on PCIe cards, using data from the `pcie_cards.json` file. 538 539It chooses the highest index from the active PCIe cards to set in the parameter. 540 541It must be configured with the following groups and properties: 542 543- The PCIe slots with the PowerState property 544- The PCIe cards with the following properties: Function0DeviceId, 545 Function0VendorId, Function0SubsystemId, Function0SubsystemVendorId 546 547``` 548{ 549 "name": "pcie_card_floors", 550 "use_config_specific_files": true, 551 "settle_time": 2 552} 553``` 554 555The `use_config_specific_files` field tells the code to look for the 556'pcie_cards.json' files in the same system specific directories as 557'events.json'. If missing or false, looks in the base fan control directory. 558 559The `settle_time` field is the amount of time in seconds that needs to pass 560without a call to run() from a group property value changing. As the PCIeDevice 561attributes are written close together by the host, this allows the action to 562wait until the writes are done before selecting the index. 563 564Additional details are in the 565[header file](../../control/json/actions/pcie_card_floors.hpp) 566 567### set_request_target_base_with_max 568 569Determines the maximum value from the properties of the group of D-Bus objects 570and sets the requested target base to this value. Only positive integer or 571floating point types are supported as these are the only valid types for a fan 572target to be based off of. 573 574The `requested target base` value is the base value to apply a target delta to. 575By default, it's the current zone target unless modified by this action. 576 577``` 578{ 579 "name": "set_request_target_base_with_max", 580 "groups": [{ 581 "name": "fan targets", 582 "interface": "xyz.openbmc_project.Fan.Target", 583 "property": { "name": "Target" } 584 }] 585} 586``` 587 588The above config will set the requested target base to the maximum Target 589property value of all members of the 'fan targets' group. 590 591### set_parameter_from_group_max 592 593Sets a parameter value based on the maximum group property value. The property 594value can be modified before storing it if the JSON specifies a valid modifier 595expression. 596 597``` 598{ 599 "name": "set_parameter_from_group_max", 600 "parameter_name": "proc_0_throttle_temp", 601 "modifier": { 602 "expression": "minus", 603 "value": 4 604 } 605} 606``` 607 608The above config will first find the max of its groups property values, subtract 6094, and then store the resulting value in the `proc_0_throttle_temp` parameter. 610 611### target_from_group_max 612 613The action sets target of Zone to a value corresponding to the maximum value 614from maximum group property value. The mapping is based on a provided table. If 615there are more than one event using this action, the maximum speed derived from 616the mapping of all groups will be set to the zone's target. 617 618... { "name": "target_from_group_max", "groups": [ { "name": "zone0_ambient", 619"interface": "xyz.openbmc_project.Sensor.Value", "property": { "name": "Value" } 620} ], "neg_hysteresis": 1, "pos_hysteresis": 0, "map": [ { "value": 10.0, 621"target": 38.0 }, ... ] } 622 623The above JSON will cause the action to read the property specified in the group 624"zone0_ambient" from all members of the group. The change in the group's members 625value will be checked against "neg_hysteresis" and "pos_hysteresis" to decide if 626it is worth taking action. "neg_hysteresis" is for the increasing case and 627"pos_hysteresis" is for the decreasing case. The maximum property value in the 628group will be mapped to the "map" to get the output "target". Each configured 629event using this action will be provided with a key in a static map to store its 630mapping result. The static map will be shared across the events of this action. 631Therefore, the updated "target" value derived from "zone0_ambient" will be 632stored in that static map with its own key. Each time it calls this action 633running for each event, after the new value is updated to the static map, the 634maximum value from it will be used to set to the Zone's target. 635 636### call_actions_based_on_timer 637 638This action starts and stops a timer that runs a list of actions whenever the 639timer expires. A timer can be either `oneshot` or `repeating`. 640 641When all groups have a configured value to compare against, that will be 642compared against all members within each group to start/stop the timer. When all 643group members have a given value and it matches what's in the cache, the timer 644is started and if any do not match, the timer is stopped. 645 646When any group does not have a configured value to be compared against, the 647groups' service owned state is used to start/stop the timer. When any service 648providing a group member is not owned, the timer is started and if all members' 649services are owned, the timer is stopped. 650 651Consider the following action config: 652 653``` 654{ 655 "name": "call_actions_based_on_timer", 656 "timer": { 657 "interval": 5000000, 658 "type": "oneshot" 659 }, 660 "actions": [{ 661 "name": "test" 662 }] 663} 664 665``` 666 667If its group configuration has a property value listed, like: 668 669``` 670{ 671 "name": "fan inventory", 672 "interface": "xyz.openbmc_project.Inventory.Item", 673 "property": { "name": "Present", "value": true } 674} 675``` 676 677Then a oneshot timer of 5000000us will be started when every member of the fan 678inventory group has a value of true. Otherwise, the timer will be stopped if 679it's running. 680 681If the group configuration has no property value listed, like: 682 683``` 684{ 685 "name": "fan inventory", 686 "interface": "xyz.openbmc_project.Inventory.Item", 687 "property": { "name": "Present" } 688} 689``` 690 691Then the timer will be started when any service providing a group member isn't 692owned (on D-Bus). Otherwise, it will stop the timer if it's running. 693 694### get_managed_objects 695 696This action adds the members of its groups to the object cache by using the 697GetManagedObjects D-Bus method to find and add the results. When that is done, 698it then runs any actions listed in the JSON. 699 700This allows an action to run with the latest values in the cache without having 701to subscribe to propertiesChanged for them all. 702 703``` 704{ 705 "name": "get_managed_objects", 706 "groups": [ 707 { 708 "name": "proc temps", 709 "interface": "xyz.openbmc_project.Sensor.Value", 710 "property": { "name": "Value" } 711 } 712 ], 713 "actions": [ 714 { 715 "name": "set_net_increase_target", 716 "state": 30, 717 "delta": 100 718 } 719 ] 720} 721``` 722 723The above config will make the GetManagedObjects call on all services that own 724the configured groups and then add all resulting property values to the object 725cache. After that, it will call the `set_net_increase_target` action using the 726same groups. 727 728## Modifiers 729 730Modifiers are used by some actions to help calculate values. 731 732### minus 733 734Subtract the `value` field from the passed in value. 735 736``` 737"modifier": { 738 "expression": "minus", 739 "value": 4 740} 741``` 742 743The above config subtracts 4 from what is passed to it. 744 745### less_than 746 747Returns a value from a data table that is selected when the argument passed in 748is less than the `arg_value` entry in the table row. If there is a 749`default_value` field supplied, then that will be returned if the argument is 750greater than the `arg_value` of the last row. 751 752``` 753"modifier": { 754 "operator": "less_than", 755 "default_value": 10000, 756 "value": [ 757 { "arg_value": 500, "parameter_value": 1 }, 758 { "arg_value": 1000, "parameter_value": 2 }, 759 { "arg_value": 1500, "parameter_value": 3 } 760 ] 761} 762``` 763 764The above config returns 1 if the arg passed is less than 500, 2 if less than 7651000, and 3 if less than 1500. Otherwise returns 10000, the default value. 766