[PATCH V2 3/4] ARM64 LPC: support serial based on low-pin-count

Arnd Bergmann
2016-09-08T09:58:08Z

On Thursday, September 8, 2016 5:51:25 PM CEST zhichang wrote:
> On 2016?09?07? 22:50, Arnd Bergmann wrote:
> > On Wednesday, September 7, 2016 9:33:52 PM CEST Zhichang Yuan wrote:
> >> From: "zhichang.yuan" <yuanzhichang@hisilicon.com>
> >>
> >> On Hip06 platform, a 16550 compatible UART is connected to low-pin-count and
> >> controlled through the LPC I/O cycles. This patch drives the UART port with
> >> the specific serial in/out function pair based on the indirect-IO mechanism
> >> introduced by Hip06 LPC driver.
> >>
> >> Signed-off-by: zhichang.yuan <yuanzhichang@hisilicon.com>
> >
> > Any reason this cannot just use the regular drivers/tty/serial/8250/8250_of.c
> > driver?
> I think two reasons for that:
> 1. 8250_of.c is only for devicetree, but we need to support ACPI device too;

ACPI has its own way of describing serial ports, use that instead.

> 2. It seems UPIO_PORT is not supported there.

Should be easy enough to add.

Arnd