From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: Re: [PATCH] [PATCH v5] mtd:spi-nor: Add Altera Quad SPI Driver Date: Thu, 20 Aug 2015 11:42:18 +0200 Message-ID: <201508201142.18586.marex@denx.de> References: <1440053705-3836-1-git-send-email-vndao@altera.com> <201508201052.47502.marex@denx.de> Mime-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Viet Nga Dao Cc: "linux-mtd@lists.infradead.org" , Brian Norris , David Woodhouse , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , nga_chi86 List-Id: devicetree@vger.kernel.org On Thursday, August 20, 2015 at 11:18:14 AM, Viet Nga Dao wrote: Hi, [...] > >> That is why we decided to upstream the > >> driver. If the hardware fix, there might not need to have any changes > >> in driver to support or if yes, it will be just minor. > > > > If the hardware can do proper READID opcode, this entire nonsense table > > will go away and a proper integration into the SPI NOR framework will > > take place. > > > > You might consider submitting this driver for staging, but I definitely > > am not a big fan of that. > > You might misunderstand the hardware problem i mention here. This soft > IP controller is able to provide the ID for our Altera EPCS/EPCQ flash > chips, which are non JEDEC chips. As from EPCQ device data sheet > (https://www.altera.com/content/dam/altera-www/global/en_US/pdfs/literature > /hb/cfg/cfg_cf52012.pdf), the device ID is 8 bit data. So what exactly is the output of READID instruction followed by 6 Byte read on an EPCQ chip? > The remaining > problem here is that this controller is able to support Micron chips but > it currently has > limitation in providing only 8 bit ID, which is not full JEDEC ID for > Micron chips. OK > Hence, we are asking hardware engineer to find out the > solution so that the driver does not need to do any dirty hacking. And > so, this table should still be here even hardware fix will take place > or not. [...] Best regards, Marek Vasut