Hi Andy, Alan

Andy Shevchenko 於 2016/1/19 下午 09:21 寫道:

quoted

Your device is multi-function. Create an MFD driver for it. Make the
8250 driver bind to the MFD, and provide your own baud rate methods
within the standard 8250 layer

Ouch, somehow I missed this one!

Peter, Alan's suggestion is really worth to try.

Thanks for point this. It seems good to probe on MFD driver, them MFD
register platform devices to invoke platform driver to initialize
sub-parts. I'll try to survey first.

But I had a new question, If I really do it with MFD subsystem, it'll
split into 3 parts, MFD probe(driver/mfd) / GPIO (driver/gpio) / UART
(drivers/tty/serial/8250). It'll cross more than 2 subsystems and 
maintainers How should I do to organize the patches?

For examples, I should remove the probe function in 8250_pci.c and
move it to new MFD file. It should organize it in the same patch as Paul
said, but this patch will need 2 subsystem maintainer to do with the
same patch, it seems weird.

Andy had cc "[PATCH v5] serial: 8250: add gpio support to exar" to me,
could I use the same way to do GPIOLIB? First add a platform driver
for F81504 gpio and add platform device into 8250_pci.c? It seems to
be good and simple to implement.

-- 
With Best Regards,
Peter Hung