Subject: Re: [PATCH] Handle reg-shift property for of_serial ports

From: Sergei Shtylyov <[email-masked]>
Date: Sat, 07 Jul 2007 21:07:21 +0400

Hello.

David Woodhouse wrote:

>>Given the existence of the boards, it looks correct to do this.
>>However, I wonder if it was correct for the MV64660 to claim
>>compatibily witn ns16550 if the programming model is not exactly
>>the same. The official OF serial port bindings don't mention the
>>reg-shift property, so it maybe would have been better to have

   I'd preferred "reg-stride" or "reg-size" but see below...

>>a different value for the "compatible" property, in order not
>>to confuse existing operating systems that implement the standard. 

> Ok, how about 'sparse16550'? Otherwise identical to ns16550, but with

    Erm, wouldn't it be *too* generic approach?  I'd suggest to name the 
device with its own name and make of_serial.c recognize it and register with 
8250.c as needed.

> the reg-shift property. I'll send a patch shortly, and I'll reorder the
> match table -- if something claims compatibility with both 8250 and
> 16550, shouldn't we drive it as the latter?

    Certainly. BTW, was there really "ns8250" -- 8250 is Intel's chip?

WBR, Sergei