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The description of dcc sysfs files is somewhat confusing and not effective. Rewrite it to be clear. While at it, also use literal code block for config sysfs examples and remove redundant examples that are obvious. Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Acked-by: Souradeep Chowdhury <quic_schowdhu@quicinc.com> Signed-off-by: Bjorn Andersson <andersson@kernel.org> Link: https://lore.kernel.org/r/20221230135030.17002-3-bagasdotme@gmail.com
128 lines
3.5 KiB
Plaintext
128 lines
3.5 KiB
Plaintext
What: /sys/kernel/debug/dcc/.../ready
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Date: December 2022
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Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
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Description:
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This file is used to check the status of the dcc
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hardware if it's ready to receive user configurations.
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A 'Y' here indicates dcc is ready.
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What: /sys/kernel/debug/dcc/.../trigger
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Date: December 2022
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Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
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Description:
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This is the debugfs interface for manual software
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triggers. The trigger can be invoked by writing '1'
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to the file.
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What: /sys/kernel/debug/dcc/.../config_reset
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Date: December 2022
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Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
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Description:
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This file is used to reset the configuration of
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a dcc driver to the default configuration. When '1'
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is written to the file, all the previous addresses
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stored in the driver gets removed and users need to
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reconfigure addresses again.
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What: /sys/kernel/debug/dcc/.../[list-number]/config
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Date: December 2022
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Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
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Description:
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This stores the addresses of the registers which
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can be read in case of a hardware crash or manual
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software triggers. The input addresses type
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can be one of following dcc instructions: read,
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write, read-write, and loop type. The lists need to
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be configured sequentially and not in a overlapping
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manner; e.g. users can jump to list x only after
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list y is configured and enabled. The input format for
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each type is as follows:
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i) Read instruction
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::
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echo R <addr> <n> <bus> >/sys/kernel/debug/dcc/../[list-number]/config
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where:
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<addr>
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The address to be read.
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<n>
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The addresses word count, starting from address <1>.
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Each word is 32 bits (4 bytes). If omitted, defaulted
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to 1.
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<bus type>
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The bus type, which can be either 'apb' or 'ahb'.
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The default is 'ahb' if leaved out.
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ii) Write instruction
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::
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echo W <addr> <n> <bus type> > /sys/kernel/debug/dcc/../[list-number]/config
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where:
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<addr>
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The address to be written.
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<n>
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The value to be written at <addr>.
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<bus type>
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The bus type, which can be either 'apb' or 'ahb'.
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iii) Read-write instruction
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::
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echo RW <addr> <n> <mask> > /sys/kernel/debug/dcc/../[list-number]/config
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where:
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<addr>
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The address to be read and written.
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<n>
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The value to be written at <addr>.
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<mask>
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The value mask.
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iv) Loop instruction
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::
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echo L <loop count> <address count> <address>... > /sys/kernel/debug/dcc/../[list-number]/config
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where:
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<loop count>
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Number of iterations
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<address count>
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total number of addresses to be written
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<address>
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Space-separated list of addresses.
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What: /sys/kernel/debug/dcc/.../[list-number]/enable
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Date: December 2022
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Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
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Description:
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This debugfs interface is used for enabling the
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the dcc hardware. A file named "enable" is in the
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directory list number where users can enable/disable
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the specific list by writing boolean (1 or 0) to the
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file.
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On enabling the dcc, all the addresses specified
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by the user for the corresponding list is written
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into dcc sram which is read by the dcc hardware
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on manual or crash induced triggers. Lists must
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be configured and enabled sequentially, e.g. list
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2 can only be enabled when list 1 have so.
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