Re: [PATCH v5 2/2] serial:sunplus-uart:Add Sunplus SoC UART Driver

hammer hsieh
2021-12-24T09:21:26Z

Hi, Greg KH:

I am still not really understand why you said the driver looks like 8250.
SP7021 SoC have our own register define.
That's why we submit a new serial driver.

Refer to:
https://sunplus.atlassian.net/wiki/spaces/doc/pages/1873412290/13.+Universal+Asynchronous+Receiver+Transmitter+UART

Regards,
Hammer Hsieh

hammer hsieh <hammerh0314@gmail.com> 於 2021年12月24日 週五 下午5:05寫道：
>
> Hi, Greg KH:
>
> 8250 driver means create driver in drivers/tty/8250/ ?
> and current I create driver in drivers/tty/serial/ not correct ?
>
> Regards,
> Hammer Hsieh
>
> Greg KH <gregkh@linuxfoundation.org> 於 2021年12月24日 週五 下午4:59寫道：
> >
> > On Fri, Dec 24, 2021 at 03:16:55PM +0800, hammer hsieh wrote:
> > > Hi, Greg KH :
> > >
> > > In patch v1 coding quite mess, it is almost 2000 LOCs.
> > > For down size code under 1000 LOCs, I decide to drop DMA function code
> > > after patch v3.
> > > I think that's the biggest difference compared with 8250.
> > > Without DMA function, like you said it looks like 8250 variant.
> > > I think I should put DMA function back in next submit.
> >
> > The 8250 driver handles DMA just fine today, why is your chip doing it
> > differently? Are you sure it is a different chip? Who created a new
> > uart chip these days?
> >
> > > Another question for why I need PORT_SLUNPLUS ?
> > > I just check many other uart driver, almost all driver define their
> > > own PORT number.
> > > Actually, I didn't know about it.
> > > Maybe some device like bluetooth(use uart port) need autoconfig.
> > > Then it will call ioctl with TIOCSERCONFIG.
> > > I don't have tool for calling type/config/request/release/verify.
> >
> > If you do not need it, and you can not test for it, please do not add
> > it.
> >
> > thanks,
> >
> > greg k-h