From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752094AbeEGIZ0 (ORCPT ); Mon, 7 May 2018 04:25:26 -0400 Received: from esa6.microchip.iphmx.com ([216.71.154.253]:44252 "EHLO esa6.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751900AbeEGIZX (ORCPT ); Mon, 7 May 2018 04:25:23 -0400 X-IronPort-AV: E=Sophos;i="5.49,373,1520924400"; d="scan'208";a="11246767" Subject: Re: [PATCH] spi-nor: Add support for Atmel Dataflash memories To: Boris Brezillon , Radu Pirea CC: , , , , , , , Tudor Ambarus - M18064 References: <1519818901-7116-1-git-send-email-radu.pirea@microchip.com> <20180504203844.0c09bf6d@bbrezillon> From: Nicolas Ferre Organization: microchip Message-ID: Date: Mon, 7 May 2018 10:23:56 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180504203844.0c09bf6d@bbrezillon> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/05/2018 at 20:38, Boris Brezillon wrote: > Hi Radu, > > Sorry for the late reply. > > On Wed, 28 Feb 2018 13:55:01 +0200 > Radu Pirea wrote: > >> This patch add support in spi-nor for allmost all dataflash memories >> supported by old mtd_dataflash driver. > > Those devices clearly use a different instruction set, so I don't think > they fit in this framework. Can you tell us why you want to move > dataflash support to the SPI NOR framework. I think I know why, but I'd > like to get your version. My guess is that some people want to connect > dataflash chips to the Atmel QSPI controller, and it's not supported > right now because the Atmel QSPI controller implements the SPI-NOR > interface and not the generic SPI one, thus preventing anything that > is not a SPI NOR from being connected to this controller. > > If I'm right, then the solution is to convert the QSPI driver to the > spi-mem interface [1] and move it to drivers/spi/. No, I we didn't think about this. Dataflash is not so popular those days and we don't want to revive it anyway. Our QSPI driver has already a lot of things to handle in QSPI-related topics to not mix it with oldies ;-) The rationale behind this work is to get rid of the very old dataflash standalone driver and benefit from the whole spi-nor infrastructure like cache coherency management and DMA handling (which were broken in the old dataflash driver in recent kernels). Best regards, Nicolas > [1]http://patchwork.ozlabs.org/project/linux-mtd/list/?series=41174 > -- Nicolas Ferre