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From: Peter Korsgaard <peter.korsgaard@barco•com>
To: linuxppc-embedded@ozlabs•org
Subject: Re: [RFC] uartlite driver MicroBlaze compatability
Date: Wed, 02 May 2007 16:09:07 +0200	[thread overview]
Message-ID: <87wszr48sc.fsf@sleipner.barco.com> (raw)
In-Reply-To: <528646bc0705012247p4a0fff63oa8d98364d5f639b0@mail.gmail.com> (Grant Likely's message of "Tue, 1 May 2007 23:47:43 -0600")

>>>>> "GL" == Grant Likely <grant.likely@secretlab•ca> writes:

Hi,

GL> Hmm, I think I was smoking something last night.

;)

GL>  Address used for 8 bit access should not be affected by CPU
GL> endianess.  After David's comments, I reread the uartlite
GL> documentation.  The current design is definately for 32bit OPB bus
GL> connections, but it looks like there is a posibility for xilinx to
GL> add a 16 or 8 bit attachment.  Since the uartlite design
GL> explicitly supports 8, 16 and 32 bit access, sticking with 8 bit
GL> io may be the safest.  However, I still think the application of
GL> the 3 byte offset should be done in the driver, and not in the
GL> platform bus registration.

That would effectively make the driver big endian only. What if Xilinx
would come out with a FPGA with a ARM core in it?

GL> I've reworked the patch with the following changes - remove 3 byte
GL> offset from platform bus registration.  - added ulite_in/ulite_out
GL> macros to make changing bus attachment details simpler if xilinx
GL> changes the uartlite design.  - stick with 8 bit IO.

Russell didn't like those accessor macros back when it was submitted
last year:

http://thread.gmane.org/gmane.linux.serial/1237/focus=1251

-- 
Bye, Peter Korsgaard

  parent reply	other threads:[~2007-05-02 14:09 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-01  4:55 [RFC] uartlite driver MicroBlaze compatability John Williams
2007-05-01  5:55 ` Grant Likely
2007-05-01  6:42   ` John Williams
2007-05-02  5:47     ` Grant Likely
2007-05-02  6:18       ` John Williams
2007-05-02 14:09       ` Peter Korsgaard [this message]
2007-05-02 15:59         ` Grant Likely
2007-05-02 13:59   ` Peter Korsgaard
2007-05-02 13:45 ` Peter Korsgaard
2007-05-03  1:08   ` John Williams
2007-05-03 10:22     ` David H. Lynch Jr.

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