17e9db9eaSCornelia HuckWhat: /sys/bus/css/devices/.../type 27e9db9eaSCornelia HuckDate: March 2008 3*ebc872d6SVineeth VijayanContact: linux-s390@vger.kernel.org 47e9db9eaSCornelia HuckDescription: Contains the subchannel type, as reported by the hardware. 57e9db9eaSCornelia Huck This attribute is present for all subchannel types. 67e9db9eaSCornelia Huck 77e9db9eaSCornelia HuckWhat: /sys/bus/css/devices/.../modalias 87e9db9eaSCornelia HuckDate: March 2008 9*ebc872d6SVineeth VijayanContact: linux-s390@vger.kernel.org 107e9db9eaSCornelia HuckDescription: Contains the module alias as reported with uevents. 117e9db9eaSCornelia Huck It is of the format css:t<type> and present for all 127e9db9eaSCornelia Huck subchannel types. 137e9db9eaSCornelia Huck 147e9db9eaSCornelia HuckWhat: /sys/bus/css/drivers/io_subchannel/.../chpids 157e9db9eaSCornelia HuckDate: December 2002 16*ebc872d6SVineeth VijayanContact: linux-s390@vger.kernel.org 177e9db9eaSCornelia HuckDescription: Contains the ids of the channel paths used by this 187e9db9eaSCornelia Huck subchannel, as reported by the channel subsystem 197e9db9eaSCornelia Huck during subchannel recognition. 2054a19b4dSMauro Carvalho Chehab 217e9db9eaSCornelia Huck Note: This is an I/O-subchannel specific attribute. 227e9db9eaSCornelia HuckUsers: s390-tools, HAL 237e9db9eaSCornelia Huck 247e9db9eaSCornelia HuckWhat: /sys/bus/css/drivers/io_subchannel/.../pimpampom 257e9db9eaSCornelia HuckDate: December 2002 26*ebc872d6SVineeth VijayanContact: linux-s390@vger.kernel.org 277e9db9eaSCornelia HuckDescription: Contains the PIM/PAM/POM values, as reported by the 287e9db9eaSCornelia Huck channel subsystem when last queried by the common I/O 2925985edcSLucas De Marchi layer (this implies that this attribute is not necessarily 307e9db9eaSCornelia Huck in sync with the values current in the channel subsystem). 3154a19b4dSMauro Carvalho Chehab 327e9db9eaSCornelia Huck Note: This is an I/O-subchannel specific attribute. 337e9db9eaSCornelia HuckUsers: s390-tools, HAL 34ebc3d179SCornelia Huck 35ebc3d179SCornelia HuckWhat: /sys/bus/css/devices/.../driver_override 36ebc3d179SCornelia HuckDate: June 2019 37*ebc872d6SVineeth VijayanContact: linux-s390@vger.kernel.org 38ebc3d179SCornelia HuckDescription: This file allows the driver for a device to be specified. When 39ebc3d179SCornelia Huck specified, only a driver with a name matching the value written 40ebc3d179SCornelia Huck to driver_override will have an opportunity to bind to the 41ebc3d179SCornelia Huck device. The override is specified by writing a string to the 42ebc3d179SCornelia Huck driver_override file (echo vfio-ccw > driver_override) and 43ebc3d179SCornelia Huck may be cleared with an empty string (echo > driver_override). 44ebc3d179SCornelia Huck This returns the device to standard matching rules binding. 45ebc3d179SCornelia Huck Writing to driver_override does not automatically unbind the 46ebc3d179SCornelia Huck device from its current driver or make any attempt to 47ebc3d179SCornelia Huck automatically load the specified driver. If no driver with a 48ebc3d179SCornelia Huck matching name is currently loaded in the kernel, the device 49ebc3d179SCornelia Huck will not bind to any driver. This also allows devices to 50ebc3d179SCornelia Huck opt-out of driver binding using a driver_override name such as 51ebc3d179SCornelia Huck "none". Only a single driver may be specified in the override, 52ebc3d179SCornelia Huck there is no support for parsing delimiters. 5354a19b4dSMauro Carvalho Chehab 54ebc3d179SCornelia Huck Note that unlike the mechanism of the same name for pci, this 55ebc3d179SCornelia Huck file does not allow to override basic matching rules. I.e., 56ebc3d179SCornelia Huck the driver must still match the subchannel type of the device. 57