From mboxrd@z Thu Jan  1 00:00:00 1970
From: Graeme Smecher <graeme.smecher@mail.mcgill.ca>
Date: Mon, 20 Sep 2010 07:43:32 -0700
Subject: [U-Boot] [PATCH V2] Adds driver for Xilinx' xps_spi SPI
	controller.
In-Reply-To: <20100918200244.D3867157D71@gemini.denx.de>
References: <201008031359.36294.vapier@gentoo.org>
	<1280955847-2999-1-git-send-email-graeme.smecher@mail.mcgill.ca>
	<20100918200244.D3867157D71@gemini.denx.de>
Message-ID: <4C977314.8080708@mail.mcgill.ca>
List-Id: <u-boot.lists.denx.de>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: u-boot@lists.denx.de

Hi Wolfgang,

On 18/09/10 01:02 PM, Wolfgang Denk wrote:
> Dear Graeme Smecher,
>
> In message<1280955847-2999-1-git-send-email-graeme.smecher@mail.mcgill.ca>  you wrote:
>    
>> This code differs in only trivial ways from the altera_spi driver. It plays
>> nice with Thomas Chou's mmc_spi driver, as well as with SPI flash.
>>      
> Hm... if the core really differs in only trivial ways from the
> altera_spi driver, then why do we need a duplication of that code?
>
> Can we plase have a single driver source that supports both instead?
>    

Hm... It's possible to combine xilinx_spi.c and altera_spi.c. However, I 
suspect joining them will make maintenance more complicated rather than 
simpler. I can't, for example, test a combined driver on Altera hardware 
(and the Altera maintainer will likely have the same problem with Xilinx 
hardware.)

My guess is that most SPI interfaces are nearly identical at a register 
level, especially for drivers that don't support interrupts and other 
complications. (See mxc_spi.c for another example.) Xilinx and Altera's 
SPI interfaces are just two examples that happen to both be FPGA-based 
-- I could probably have adapted any of the other SPI drivers instead.

Are you sure combining drivers is the most logical approach? Let me 
know, and I'll have a crack at it.

thanks,
Graeme