Re: [PATCH v4 2/2] misc: Add iop driver for Sunplus SP7021

On Fri, Dec 17, 2021 at 02:44:43AM +0000, Tony Huang 黃懷厚 wrote:

Dear Arnd:

On Thu, Dec 16, 2021 at 2:38 AM Tony Huang <tonyhuang.sunplus@gmail.com<mailto:tonyhuang.sunplus@gmail.com>> wrote:

quoted

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<mailto:tonyhuang.sunplus@gmail.com>>
---
Changes in v4:
 - Addressed comments from Arnd Bergmann.

quoted

I don't think you did: I asked you specifically to add code to interact with
the existing in-kernel interfaces to use the functionality provided by the
device. Pick any (at least two) subsystems and add support, but leave
out any custom user space interfaces (miscdevice, debugfs, sysfs, ...)
for the moment.

1. IOP can run sp_iop_platform_driver_shudown() through the poweroff command and the kernel. Perform system power-off actions.
2. Wake up the system by relying on the 8051 internal RTC wake-up mechanism and external GPIO input signals to wake up.
3.So you ask me to control IOP(8051) through file_operations, not through DEVICE_ATTR

Your DEVICE_ATTR() calls did not do anything normal, they did not print
out or accept data through sysfs at all.  That is not ok.

thanks,

greg k-h