On Fri, Dec 17, 2021 at 03:16:53PM +0000, Tony Huang 黃懷厚 wrote:

Dear Arnd:

quoted

On Thu, Dec 9, 2021 at 9:58 AM Tony Huang [off-list ref]
wrote:

quoted

IOP (IO Processor) embedded inside SP7021 which is used as Processor
for I/O control, RTC wake-up and cooperation with CPU & PMC in power
management purpose.
The IOP core is DQ8051, so also named IOP8051, it supports dedicated
JTAG debug pins which share with SP7021.
In standby mode operation, the power spec reach 400uA.

Signed-off-by: Tony Huang <tonyhuang.sunplus@gmail.com>

Thanks for the improvements, this again looks better than the previous version.
I still have some minor comments, and there are a couple of details I have
commented on before that would need to be addressed, but let's focus on the
one main issue for now:

The driver still doesn't actually /do/ anything: you load the firmware when the
driver is loaded, and you shut it down when the driver is removed, but
otherwise there is no way to interact with the iop. You had the miscdevice
earlier, and you still register that, but there are no file_operations associated
with it, so it still doesn't have any effect.

In the original version you had a couple of user-side interfaces, for which Greg
and I commented that they were not using the correct abstractions, and you
still list them in the changelog text as "I/O control, RTC wake-up and
cooperation with CPU & PMC in power management".

If you want to make any progress with adding the driver, I'd say you should
implement at least two of those high-level interfaces that interact with the
respective kernel subsystems in order to show that the abstraction works.

Q:"with respective kernel subsystems in order to show that the abstraction works."
May I ask you about repective kernel subsystem.
If I use the file_operation method
Provide user can read and write IOP(8051)'s register.
Is this a repective kernel subsystem?
if not
There are other driver code can give me reference

I still do not understand what the goal of this driver is.

What is the problem that you are needing to solve?  What needs to access
this hardware, and what exactly was this hardware designed to do?

thanks,

greg k-h