On Tue, Dec 27, 2022 at 08:52:46PM +0530, Souradeep Chowdhury wrote: > The DCC is a DMA Engine designed to capture and store data > during system crash or software triggers. The DCC operates > based on user inputs via the debugfs interface. The user gives > addresses as inputs and these addresses are stored in the > dcc sram. In case of a system crash or a manual software > trigger by the user through the debugfs interface, > the dcc captures and stores the values at these addresses. > This patch contains the driver which has all the methods > pertaining to the debugfs interface, auxiliary functions to > support all the four fundamental operations of dcc namely > read, write, read/modify/write and loop. The probe method > here instantiates all the resources necessary for dcc to > operate mainly the dedicated dcc sram where it stores the > values. The DCC driver can be used for debugging purposes > without going for a reboot since it can perform software > triggers as well based on user inputs. > > Also add the documentation for debugfs entries which explains > the functionalities of each debugfs file that has been created > for dcc. > > The following is the justification of using debugfs interface > over the other alternatives like sysfs/ioctls > > i) As can be seen from the debugfs attribute descriptions, > some of the debugfs attribute files here contains multiple > arguments which needs to be accepted from the user. This goes > against the design style of sysfs. > > ii) The user input patterns have been made simple and convenient > in this case with the use of debugfs interface as user doesn't > need to shuffle between different files to execute one instruction > as was the case on using other alternatives. > I would have preferred to get some more input from users of the debugfs interface, but it's after all not ABI. So let's get this merged and if people has concerns/objections/suggestions we'll improve it as necessary. Thanks for pushing this Souradeep! > Signed-off-by: Souradeep Chowdhury <quic_schowdhu@xxxxxxxxxxx> > Reviewed-by: Alex Elder <elder@xxxxxxxxxx> Thanks Alex. Regards, Bjorn
