1What: /sys/bus/css/devices/.../type 2Date: March 2008 3Contact: linux-s390@vger.kernel.org 4Description: Contains the subchannel type, as reported by the hardware. 5 This attribute is present for all subchannel types. 6 7What: /sys/bus/css/devices/.../modalias 8Date: March 2008 9Contact: linux-s390@vger.kernel.org 10Description: Contains the module alias as reported with uevents. 11 It is of the format css:t<type> and present for all 12 subchannel types. 13 14What: /sys/bus/css/drivers/io_subchannel/.../chpids 15Date: December 2002 16Contact: linux-s390@vger.kernel.org 17Description: Contains the ids of the channel paths used by this 18 subchannel, as reported by the channel subsystem 19 during subchannel recognition. 20 21 Note: This is an I/O-subchannel specific attribute. 22Users: s390-tools, HAL 23 24What: /sys/bus/css/drivers/io_subchannel/.../pimpampom 25Date: December 2002 26Contact: linux-s390@vger.kernel.org 27Description: Contains the PIM/PAM/POM values, as reported by the 28 channel subsystem when last queried by the common I/O 29 layer (this implies that this attribute is not necessarily 30 in sync with the values current in the channel subsystem). 31 32 Note: This is an I/O-subchannel specific attribute. 33Users: s390-tools, HAL 34 35What: /sys/bus/css/devices/.../driver_override 36Date: June 2019 37Contact: linux-s390@vger.kernel.org 38Description: This file allows the driver for a device to be specified. When 39 specified, only a driver with a name matching the value written 40 to driver_override will have an opportunity to bind to the 41 device. The override is specified by writing a string to the 42 driver_override file (echo vfio-ccw > driver_override) and 43 may be cleared with an empty string (echo > driver_override). 44 This returns the device to standard matching rules binding. 45 Writing to driver_override does not automatically unbind the 46 device from its current driver or make any attempt to 47 automatically load the specified driver. If no driver with a 48 matching name is currently loaded in the kernel, the device 49 will not bind to any driver. This also allows devices to 50 opt-out of driver binding using a driver_override name such as 51 "none". Only a single driver may be specified in the override, 52 there is no support for parsing delimiters. 53 54 Note that unlike the mechanism of the same name for pci, this 55 file does not allow to override basic matching rules. I.e., 56 the driver must still match the subchannel type of the device. 57