Re: [RFC PATCH 0/2] serial: 8250_dw: IO space + polling mode support

From: John Garry
Date: Mon Feb 26 2018 - 05:46:24 EST



Hi Andy,

We require it for a development board for our hip06 platform.

Okay, and this particular platform uses Synopsys IP?

As I see this uart is really a virtual 8250, so HW details like apb
clocks and the like are hidden, so may not be relevant.

Good to know.

However I will check with the BMC team to know the specific details.

for supporting an 8250-compatible UART with
the following profile/features:
- platform device
- polling mode (i.e. no interrupt support)
- ACPI FW

Elaborate this one, please.

So we need to define our own HID here, and cannot use PNP
compatible
CID
(like PNP0501) as we cannot use the 8250 PNP driver.

Why not? What are the impediments?


To support the host controller for this device, we will create an
MFD,
i.e. platform device, per slave device.

There is no answer here...

This is related to the Hisi LPC ACPI support, where we would
create
an
MFD (i.e. platform device) for the UART.

Why you can't do properly in ACPI?

No answer here either.

Sorry, but with this level of communication it's no go for the series.


Sorry if my answers did not tell you want you want to know.

My point was that the 8250_pnp driver would be used for a pnp_device, but we are creating a platform device for this UART slave so would require a platform device driver, that which 8250_dw.c is. But I will check on pnp device support.

Much appreciated,
John