1What: /sys/kernel/debug/dcc/.../ready 2Date: December 2022 3Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com> 4Description: 5 This file is used to check the status of the dcc 6 hardware if it's ready to take the inputs. A 'Y' 7 here indicates dcc is in a ready condition. 8 Example: 9 cat /sys/kernel/debug/dcc/.../ready 10 11What: /sys/kernel/debug/dcc/.../trigger 12Date: December 2022 13Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com> 14Description: 15 This is the debugfs interface for manual software 16 triggers. The user can simply enter a 1 against 17 the debugfs file and enable a manual trigger. 18 Example: 19 echo 1 > /sys/kernel/debug/dcc/.../trigger 20 21What: /sys/kernel/debug/dcc/.../config_reset 22Date: December 2022 23Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com> 24Description: 25 This file is used to reset the configuration of 26 a dcc driver to the default configuration. This 27 means that all the previous addresses stored in 28 the driver gets removed and user needs to enter 29 the address values from the start. 30 Example: 31 echo 1 > /sys/kernel/debug/dcc/../config_reset 32 33What: /sys/kernel/debug/dcc/.../[list-number]/config 34Date: December 2022 35Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com> 36Description: 37 This stores the addresses of the registers which 38 should be read in case of a hardware crash or 39 manual software triggers. The addresses entered here 40 are considered under all the 4 types of dcc 41 instructions Read type, Write type, Read Modify Write 42 type and Loop type. The lists need to be configured 43 sequentially and not in a overlapping manner. As an 44 example user can jump to list x only after list y is 45 configured and enabled. The format for entering all 46 types of instructions are explained in examples as 47 follows. 48 Example: 49 i)Read Type Instruction 50 echo R <1> <2> <3> >/sys/kernel/debug/dcc/../[list-number]/config 51 1->Address to be considered for reading the value. 52 2->The word count of the addresses, read n words 53 starting from address <1>. Each word is of 32 bits. 54 If not entered 1 is considered. 55 3->Can be 'apb' or 'ahb' which indicates if it is apb or ahb 56 bus respectively. If not entered ahb is considered. 57 ii)Write Type Instruction 58 echo W <1> <2> <3> > /sys/kernel/debug/dcc/../[list-number]/config 59 1->Address to be considered for writing the value. 60 2->The value that needs to be written at the location. 61 3->Can be a 'apb' or 'ahb' which indicates if it is apb or ahb 62 but respectively. 63 iii)Read Modify Write type instruction 64 echo RW <1> <2> <3> > /sys/kernel/debug/dcc/../[list-number]/config 65 1->The address which needs to be considered for read then write. 66 2->The value that needs to be written on the address. 67 3->The mask of the value to be written. 68 iv)Loop Type Instruction 69 echo L <1> <2> <3> > /sys/kernel/debug/dcc/../[list-number]/config 70 1->The loop count, the number of times the value of the addresses will be 71 captured. 72 2->The address count, total number of addresses to be entered in this 73 instruction. 74 3->The series of addresses to be entered separated by a space like <addr1> 75 <addr2>... and so on. 76 77What: /sys/kernel/debug/dcc/.../[list-number]/enable 78Date: December 2022 79Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com> 80Description: 81 This debugfs interface is used for enabling the 82 the dcc hardware. Enable file is kept under the 83 directory list number for which the user wants 84 to enable it. For example if the user wants to 85 enable list 1, then he should go for 86 echo 1 > /sys/kernel/debug/dcc/.../1/enable. 87 On enabling the dcc, all the addresses entered 88 by the user for the corresponding list is written 89 into dcc sram which is read by the dcc hardware 90 on manual or crash induced triggers. Lists should 91 be enabled sequentially.For example after configuring 92 addresses for list 1 and enabling it, a user can 93 proceed to enable list 2 or vice versa. 94 Example: 95 echo 0 > /sys/kernel/debug/dcc/.../[list-number]/enable 96 (disable dcc for the corresponding list number) 97 echo 1 > /sys/kernel/debug/dcc/.../[list-number]/enable 98 (enable dcc for the corresponding list number) 99