13f697027SMichael Walle.. SPDX-License-Identifier: GPL-2.0-only 23f697027SMichael Walle 33f697027SMichael WalleKernel driver sl28cpld 43f697027SMichael Walle====================== 53f697027SMichael Walle 63f697027SMichael WalleSupported chips: 73f697027SMichael Walle 83f697027SMichael Walle * Kontron sl28cpld 93f697027SMichael Walle 103f697027SMichael Walle Prefix: 'sl28cpld' 113f697027SMichael Walle 123f697027SMichael Walle Datasheet: not available 133f697027SMichael Walle 143f697027SMichael WalleAuthors: Michael Walle <michael@walle.cc> 153f697027SMichael Walle 163f697027SMichael WalleDescription 173f697027SMichael Walle----------- 183f697027SMichael Walle 193f697027SMichael WalleThe sl28cpld is a board management controller which also exposes a hardware 203f697027SMichael Wallemonitoring controller. At the moment this controller supports a single fan 213f697027SMichael Wallesupervisor. In the future there might be other flavours and additional 223f697027SMichael Wallehardware monitoring might be supported. 233f697027SMichael Walle 243f697027SMichael WalleThe fan supervisor has a 7 bit counter register and a counter period of 1 253f697027SMichael Wallesecond. If the 7 bit counter overflows, the supervisor will automatically 263f697027SMichael Walleswitch to x8 mode to support a wider input range at the loss of 273f697027SMichael Wallegranularity. 283f697027SMichael Walle 293f697027SMichael WalleSysfs entries 303f697027SMichael Walle------------- 313f697027SMichael Walle 323f697027SMichael WalleThe following attributes are supported. 333f697027SMichael Walle 343f697027SMichael Walle======================= ======================================================== 353f697027SMichael Wallefan1_input Fan RPM. Assuming 2 pulses per revolution. 363f697027SMichael Walle======================= ======================================================== 37