|  | What:		/sys/bus/platform/devices/dfl-port.0/id | 
|  | Date:		June 2018 | 
|  | KernelVersion:	4.19 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-only. It returns id of this port. One DFL FPGA device | 
|  | may have more than one port. Userspace could use this id to | 
|  | distinguish different ports under same FPGA device. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/afu_id | 
|  | Date:		June 2018 | 
|  | KernelVersion:	4.19 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-only. User can program different PR bitstreams to FPGA | 
|  | Accelerator Function Unit (AFU) for different functions. It | 
|  | returns uuid which could be used to identify which PR bitstream | 
|  | is programmed in this AFU. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/power_state | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-only. It reports the APx (AFU Power) state, different APx | 
|  | means different throttling level. When reading this file, it | 
|  | returns "0" - Normal / "1" - AP1 / "2" - AP2 / "6" - AP6. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/ap1_event | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-write. Read this file for AP1 (AFU Power State 1) event. | 
|  | It's used to indicate transient AP1 state. Write 1 to this | 
|  | file to clear AP1 event. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/ap2_event | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-write. Read this file for AP2 (AFU Power State 2) event. | 
|  | It's used to indicate transient AP2 state. Write 1 to this | 
|  | file to clear AP2 event. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/ltr | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-write. Read or set AFU latency tolerance reporting value. | 
|  | Set ltr to 1 if the AFU can tolerate latency >= 40us or set it | 
|  | to 0 if it is latency sensitive. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqcmd | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Write-only. User writes command to this interface to set | 
|  | userclock to AFU. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqsts | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-only. Read this file to get the status of issued command | 
|  | to userclck_freqcmd. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqcntrcmd | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Write-only. User writes command to this interface to set | 
|  | userclock counter. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/userclk_freqcntrsts | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-only. Read this file to get the status of issued command | 
|  | to userclck_freqcntrcmd. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/errors/errors | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-Write. Read this file to get errors detected on port and | 
|  | Accelerated Function Unit (AFU). Write error code to this file | 
|  | to clear errors. Write fails with -EINVAL if input parsing | 
|  | fails or input error code doesn't match. Write fails with | 
|  | -EBUSY or -ETIMEDOUT if error can't be cleared as hardware | 
|  | in low power state (-EBUSY) or not respoding (-ETIMEDOUT). | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/errors/first_error | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-only. Read this file to get the first error detected by | 
|  | hardware. | 
|  |  | 
|  | What:		/sys/bus/platform/devices/dfl-port.0/errors/first_malformed_req | 
|  | Date:		August 2019 | 
|  | KernelVersion:	5.4 | 
|  | Contact:	Wu Hao <hao.wu@intel.com> | 
|  | Description:	Read-only. Read this file to get the first malformed request | 
|  | captured by hardware. |