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 49 i) Read Type Instruction 50 51 echo R <1> <2> <3> >/sys/kernel/debug/dcc/../[list-number]/config 52 53 1->Address to be considered for reading the value. 54 55 2->The word count of the addresses, read n words 56 starting from address <1>. Each word is of 32 bits. 57 If not entered 1 is considered. 58 59 3->Can be 'apb' or 'ahb' which indicates if it is apb or ahb 60 bus respectively. If not entered ahb is considered. 61 62 ii) Write Type Instruction 63 64 echo W <1> <2> <3> > /sys/kernel/debug/dcc/../[list-number]/config 65 66 1->Address to be considered for writing the value. 67 68 2->The value that needs to be written at the location. 69 70 3->Can be a 'apb' or 'ahb' which indicates if it is apb or ahb 71 but respectively. 72 73 iii) Read Modify Write type instruction 74 75 echo RW <1> <2> <3> > /sys/kernel/debug/dcc/../[list-number]/config 76 77 1->The address which needs to be considered for read then write. 78 79 2->The value that needs to be written on the address. 80 81 3->The mask of the value to be written. 82 83 iv) Loop Type Instruction 84 85 echo L <1> <2> <3> > /sys/kernel/debug/dcc/../[list-number]/config 86 87 1->The loop count, the number of times the value of the addresses will be 88 captured. 89 90 2->The address count, total number of addresses to be entered in this 91 instruction. 92 93 3->The series of addresses to be entered separated by a space like <addr1> 94 <addr2>... and so on. 95 96What: /sys/kernel/debug/dcc/.../[list-number]/enable 97Date: December 2022 98Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com> 99Description: 100 This debugfs interface is used for enabling the 101 the dcc hardware. Enable file is kept under the 102 directory list number for which the user wants 103 to enable it. For example if the user wants to 104 enable list 1, then he should go for 105 echo 1 > /sys/kernel/debug/dcc/.../1/enable. 106 On enabling the dcc, all the addresses entered 107 by the user for the corresponding list is written 108 into dcc sram which is read by the dcc hardware 109 on manual or crash induced triggers. Lists should 110 be enabled sequentially.For example after configuring 111 addresses for list 1 and enabling it, a user can 112 proceed to enable list 2 or vice versa. 113 Example: 114 echo 0 > /sys/kernel/debug/dcc/.../[list-number]/enable 115 (disable dcc for the corresponding list number) 116 echo 1 > /sys/kernel/debug/dcc/.../[list-number]/enable 117 (enable dcc for the corresponding list number) 118