1*3f697027SMichael Walle.. SPDX-License-Identifier: GPL-2.0-only 2*3f697027SMichael Walle 3*3f697027SMichael WalleKernel driver sl28cpld 4*3f697027SMichael Walle====================== 5*3f697027SMichael Walle 6*3f697027SMichael WalleSupported chips: 7*3f697027SMichael Walle 8*3f697027SMichael Walle * Kontron sl28cpld 9*3f697027SMichael Walle 10*3f697027SMichael Walle Prefix: 'sl28cpld' 11*3f697027SMichael Walle 12*3f697027SMichael Walle Datasheet: not available 13*3f697027SMichael Walle 14*3f697027SMichael WalleAuthors: Michael Walle <michael@walle.cc> 15*3f697027SMichael Walle 16*3f697027SMichael WalleDescription 17*3f697027SMichael Walle----------- 18*3f697027SMichael Walle 19*3f697027SMichael WalleThe sl28cpld is a board management controller which also exposes a hardware 20*3f697027SMichael Wallemonitoring controller. At the moment this controller supports a single fan 21*3f697027SMichael Wallesupervisor. In the future there might be other flavours and additional 22*3f697027SMichael Wallehardware monitoring might be supported. 23*3f697027SMichael Walle 24*3f697027SMichael WalleThe fan supervisor has a 7 bit counter register and a counter period of 1 25*3f697027SMichael Wallesecond. If the 7 bit counter overflows, the supervisor will automatically 26*3f697027SMichael Walleswitch to x8 mode to support a wider input range at the loss of 27*3f697027SMichael Wallegranularity. 28*3f697027SMichael Walle 29*3f697027SMichael WalleSysfs entries 30*3f697027SMichael Walle------------- 31*3f697027SMichael Walle 32*3f697027SMichael WalleThe following attributes are supported. 33*3f697027SMichael Walle 34*3f697027SMichael Walle======================= ======================================================== 35*3f697027SMichael Wallefan1_input Fan RPM. Assuming 2 pulses per revolution. 36*3f697027SMichael Walle======================= ======================================================== 37