soc: qcom: dcc: rewrite description of dcc sysfs files

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
This commit is contained in:
Bagas Sanjaya 2022-12-30 20:50:31 +07:00 committed by Bjorn Andersson
parent dc2f5a499d
commit 13763fb955
1 changed files with 76 additions and 66 deletions

View File

@ -3,115 +3,125 @@ Date: December 2022
Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
Description:
This file is used to check the status of the dcc
hardware if it's ready to take the inputs. A 'Y'
here indicates dcc is in a ready condition.
Example:
cat /sys/kernel/debug/dcc/.../ready
hardware if it's ready to receive user configurations.
A 'Y' here indicates dcc is ready.
What: /sys/kernel/debug/dcc/.../trigger
Date: December 2022
Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
Description:
This is the debugfs interface for manual software
triggers. The user can simply enter a 1 against
the debugfs file and enable a manual trigger.
Example:
echo 1 > /sys/kernel/debug/dcc/.../trigger
triggers. The trigger can be invoked by writing '1'
to the file.
What: /sys/kernel/debug/dcc/.../config_reset
Date: December 2022
Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
Description:
This file is used to reset the configuration of
a dcc driver to the default configuration. This
means that all the previous addresses stored in
the driver gets removed and user needs to enter
the address values from the start.
Example:
echo 1 > /sys/kernel/debug/dcc/../config_reset
a dcc driver to the default configuration. When '1'
is written to the file, all the previous addresses
stored in the driver gets removed and users need to
reconfigure addresses again.
What: /sys/kernel/debug/dcc/.../[list-number]/config
Date: December 2022
Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
Description:
This stores the addresses of the registers which
should be read in case of a hardware crash or
manual software triggers. The addresses entered here
are considered under all the 4 types of dcc
instructions Read type, Write type, Read Modify Write
type and Loop type. The lists need to be configured
sequentially and not in a overlapping manner. As an
example user can jump to list x only after list y is
configured and enabled. The format for entering all
types of instructions are explained in examples as
follows:
can be read in case of a hardware crash or manual
software triggers. The input addresses type
can be one of following dcc instructions: read,
write, read-write, and loop type. The lists need to
be configured sequentially and not in a overlapping
manner; e.g. users can jump to list x only after
list y is configured and enabled. The input format for
each type is as follows:
i) Read Type Instruction
i) Read instruction
echo R <1> <2> <3> >/sys/kernel/debug/dcc/../[list-number]/config
::
1->Address to be considered for reading the value.
echo R <addr> <n> <bus> >/sys/kernel/debug/dcc/../[list-number]/config
2->The word count of the addresses, read n words
starting from address <1>. Each word is of 32 bits.
If not entered 1 is considered.
where:
3->Can be 'apb' or 'ahb' which indicates if it is apb or ahb
bus respectively. If not entered ahb is considered.
<addr>
The address to be read.
ii) Write Type Instruction
<n>
The addresses word count, starting from address <1>.
Each word is 32 bits (4 bytes). If omitted, defaulted
to 1.
echo W <1> <2> <3> > /sys/kernel/debug/dcc/../[list-number]/config
<bus type>
The bus type, which can be either 'apb' or 'ahb'.
The default is 'ahb' if leaved out.
1->Address to be considered for writing the value.
ii) Write instruction
2->The value that needs to be written at the location.
::
3->Can be a 'apb' or 'ahb' which indicates if it is apb or ahb
but respectively.
echo W <addr> <n> <bus type> > /sys/kernel/debug/dcc/../[list-number]/config
iii) Read Modify Write type instruction
where:
echo RW <1> <2> <3> > /sys/kernel/debug/dcc/../[list-number]/config
<addr>
The address to be written.
1->The address which needs to be considered for read then write.
<n>
The value to be written at <addr>.
2->The value that needs to be written on the address.
<bus type>
The bus type, which can be either 'apb' or 'ahb'.
3->The mask of the value to be written.
iii) Read-write instruction
iv) Loop Type Instruction
::
echo L <1> <2> <3> > /sys/kernel/debug/dcc/../[list-number]/config
echo RW <addr> <n> <mask> > /sys/kernel/debug/dcc/../[list-number]/config
1->The loop count, the number of times the value of the addresses will be
captured.
where:
2->The address count, total number of addresses to be entered in this
instruction.
<addr>
The address to be read and written.
3->The series of addresses to be entered separated by a space like <addr1>
<addr2>... and so on.
<n>
The value to be written at <addr>.
<mask>
The value mask.
iv) Loop instruction
::
echo L <loop count> <address count> <address>... > /sys/kernel/debug/dcc/../[list-number]/config
where:
<loop count>
Number of iterations
<address count>
total number of addresses to be written
<address>
Space-separated list of addresses.
What: /sys/kernel/debug/dcc/.../[list-number]/enable
Date: December 2022
Contact: Souradeep Chowdhury <quic_schowdhu@quicinc.com>
Description:
This debugfs interface is used for enabling the
the dcc hardware. Enable file is kept under the
directory list number for which the user wants
to enable it. For example if the user wants to
enable list 1, then he should go for
echo 1 > /sys/kernel/debug/dcc/.../1/enable.
On enabling the dcc, all the addresses entered
the dcc hardware. A file named "enable" is in the
directory list number where users can enable/disable
the specific list by writing boolean (1 or 0) to the
file.
On enabling the dcc, all the addresses specified
by the user for the corresponding list is written
into dcc sram which is read by the dcc hardware
on manual or crash induced triggers. Lists should
be enabled sequentially.For example after configuring
addresses for list 1 and enabling it, a user can
proceed to enable list 2 or vice versa.
Example:
echo 0 > /sys/kernel/debug/dcc/.../[list-number]/enable
(disable dcc for the corresponding list number)
echo 1 > /sys/kernel/debug/dcc/.../[list-number]/enable
(enable dcc for the corresponding list number)
on manual or crash induced triggers. Lists must
be configured and enabled sequentially, e.g. list
2 can only be enabled when list 1 have so.