Messages in this thread | ![/](/images/icornerl.gif) | | Date | Thu, 11 Apr 2024 14:58:52 +0530 | From | Vinod Koul <> | Subject | Re: [PATCH 6/7] soundwire: debugfs: add interface to read/write commands |
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On 05-04-24, 10:12, Pierre-Louis Bossart wrote: > On 4/5/24 06:45, Vinod Koul wrote: > > On 26-03-24, 09:01, Bard Liao wrote: > >> From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> > >> > >> We have an existing debugfs files to read standard registers > >> (DP0/SCP/DPn). > >> > >> This patch provides a more generic interface to ANY set of read/write > >> contiguous registers in a peripheral device. In follow-up patches, > >> this interface will be extended to use BRA transfers. > >> > >> The sequence is to use the following files added under the existing > >> debugsfs directory for each peripheral device: > >> > >> command (write 0, read 1) > >> num_bytes > >> start_address > >> firmware_file (only for writes) > >> read_buffer (only for reads) > >> > >> Example for a read command - this checks the 6 bytes used for > >> enumeration. > >> > >> cd /sys/kernel/debug/soundwire/master-0-0/sdw\:0\:025d\:0711\:01/ > >> echo 1 > command > >> echo 6 > num_bytes > >> echo 0x50 > start_address > >> echo 1 > go > > > > can we have a simpler interface? i am not a big fan of this kind of > > structure for debugging. > > > > How about two files read_bytes and write_bytes where you read/write > > bytes. > > > > echo 0x50 6 > read_bytes > > cat read_bytes > > > > in this format I would like to see addr and values (not need to print > > address /value words (regmap does that too) > > > > For write > > > > echo start_addr N byte0 byte 1 ... byte N > write_bytes > > I think you missed the required extension where we will add a new > 'command_type' to specify which of the regular or BTP/BRA accesses is used. > > Also the bytes can come from a firmware file, it would be very odd to > have a command line with 32k value, wouldn't it?
ofc no one should expect that... it should be written directly from the firmware file
> I share your concern about making the interface as simple as possible, > but I don't see how it can be made simpler really. We have to specify > - read/write > - access type (BRA or regular) > - start address > - number of bytes > - a firmware file for writes > - a means to see the read data. > > And I personally prefer one 1:1 mapping between setting and debugfs > file, rather than a M:1 mapping that require users to think about the > syntax and which value maps to what setting. At my age I have to define > things that I will remember on the next Monday.
Exactly, you won't remember all the files to write to, my idea was a simple format or addr, N and data.. a TLV kind of structure..
What would happen if you issue go, but missed writing one of the files. Also I would expect you to do error checking of inputs...
Thanks -- ~Vinod
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