From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C070C04EB8 for ; Mon, 10 Dec 2018 11:04:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1436820821 for ; Mon, 10 Dec 2018 11:04:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1436820821 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727323AbeLJLEO (ORCPT ); Mon, 10 Dec 2018 06:04:14 -0500 Received: from mail.bootlin.com ([62.4.15.54]:56601 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726716AbeLJLEN (ORCPT ); Mon, 10 Dec 2018 06:04:13 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id 40E362079D; Mon, 10 Dec 2018 12:04:10 +0100 (CET) Received: from bbrezillon (unknown [91.160.177.164]) by mail.bootlin.com (Postfix) with ESMTPSA id DF0E820CEB; Mon, 10 Dec 2018 12:03:59 +0100 (CET) Date: Mon, 10 Dec 2018 12:03:59 +0100 From: Boris Brezillon To: Yogesh Narayan Gaur Cc: Schrempf Frieder , "linux-mtd@lists.infradead.org" , "marek.vasut@gmail.com" , "broonie@kernel.org" , "linux-spi@vger.kernel.org" , "devicetree@vger.kernel.org" , "robh@kernel.org" , "mark.rutland@arm.com" , "shawnguo@kernel.org" , "linux-arm-kernel@lists.infradead.org" , "computersforpeace@gmail.com" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v5 1/5] spi: spi-mem: Add driver for NXP FlexSPI controller Message-ID: <20181210120359.24a2ea9a@bbrezillon> In-Reply-To: References: <1542366701-16065-1-git-send-email-yogeshnarayan.gaur@nxp.com> <1542366701-16065-2-git-send-email-yogeshnarayan.gaur@nxp.com> <20181210111909.35384eee@bbrezillon> <20181210115001.6c7af1d7@bbrezillon> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 10 Dec 2018 10:59:54 +0000 Yogesh Narayan Gaur wrote: > Hi Boris, > > > -----Original Message----- > > From: Boris Brezillon [mailto:boris.brezillon@bootlin.com] > > Sent: Monday, December 10, 2018 4:20 PM > > To: Yogesh Narayan Gaur > > Cc: Schrempf Frieder ; linux- > > mtd@lists.infradead.org; marek.vasut@gmail.com; broonie@kernel.org; linux- > > spi@vger.kernel.org; devicetree@vger.kernel.org; robh@kernel.org; > > mark.rutland@arm.com; shawnguo@kernel.org; linux-arm- > > kernel@lists.infradead.org; computersforpeace@gmail.com; linux- > > kernel@vger.kernel.org > > Subject: Re: [PATCH v5 1/5] spi: spi-mem: Add driver for NXP FlexSPI controller > > > > On Mon, 10 Dec 2018 10:43:56 +0000 > > Yogesh Narayan Gaur wrote: > > > > > > > Thus, in LUT preparation we have assigned only the base address. > > > > > Now if I have assigned ahb_buf_size to FSPI_FLSHXXCR0 register > > > > > then for > > > > read/write data beyond limit of ahb_buf_size offset I get data corruption. > > > > > > > > Why would you do that? We have the ->adjust_op_size() exactly for > > > > this reason, so, if someone tries to do a spi_mem_op with > > > > data.nbytes > ahb_buf_size you should return an error. > > > > > > > Let me explain my implementation with example. If I have to write data of size > > 0x100 bytes at offset 0x1200 for CS1, I would program as below: > > > In func nxp_fspi_select_mem(), would set value of controller address space > > size, memmap_phy_size, to FSPI_FLSHA2CR0 and rest all FSPI_FLSHXXCR0 as 0. > > > Value of memmap_phy_size is 0x10000000 i.e. 256 MB for my LX2160ARDB > > target. > > > Then in nxp_fspi_prepare_lut(), I would prepare LUT ADDR with address length > > requirement 3/4 byte for NOR or 1/2/3/4 bytes for NAND flash. > > > Also for LUT_NXP_WRITE would program data bytes as 0. > > > > > > Then inside func nxp_fspi_do_op(), set register FSPI_IPCR0 as the > > > address offset i.e. 0x1200 and in register FSPI_IPCR1 program the data > > > size to write i.e. 0x100 > > > > > > If, as suggested if I tries to mark value of register FSPI_FLSHA2CR0 equal to > > ahb_buf_size (0x800), then access for address 0x1200 gives me wrong data. This > > is because as per the controller specification access to flash connected at CS1 > > can be performed under range of FSPI_ FLSHA1CR0 and FSPI_ FLSHA2CR0. > > > > Don't you have a way to set an offset to apply to the address accessed through > > the AHB? And if you don't, how will it work if your mapping is smaller than the > > flash size? > > Write operations are triggered using IP commands instead of AHB command. > For Read AHB command is used and in this we are adding the offset when performing memcpy_fromIO operation > memcpy_fromio(op->data.buf.in, (f->ahb_addr + op->addr.val), len); > > AHB/IP operations are independent of the way how CS got selected. CS selection depends, e.g. CS1 on the value of register FSPI_FLSHA1CR0 and FSPI_FLSHA2CR0. > > Mapping can never going to be smaller than the connected flash size as per discussion with the Board design team and if it's possible by user manually changes the non-soldered part then flash area beyond complete mapping is not accessible. How unfortunate is that, especially when all that was required was an extra reg to specify a "flash_offset" to apply to the address passed by the AHB logic.