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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no 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 80917C31E40 for ; Fri, 9 Aug 2019 15:26:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4963421881 for ; Fri, 9 Aug 2019 15:26:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407393AbfHIP0B (ORCPT ); Fri, 9 Aug 2019 11:26:01 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:53248 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726358AbfHIP0B (ORCPT ); Fri, 9 Aug 2019 11:26:01 -0400 Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id C093628CFB2; Fri, 9 Aug 2019 16:25:59 +0100 (BST) Date: Fri, 9 Aug 2019 17:25:57 +0200 From: Boris Brezillon To: Tomer Maimon Cc: Mark Brown , Rob Herring , Mark Rutland , Vignesh Raghavendra , Boris Brezillon , Avi Fishman , Tali Perry , Patrick Venture , Nancy Yuen , Benjamin Fair , linux-spi@vger.kernel.org, devicetree , OpenBMC Maillist , Linux Kernel Mailing List Subject: Re: [PATCH v2 2/2] spi: npcm-fiu: add NPCM FIU controller driver Message-ID: <20190809172557.346e7c41@collabora.com> In-Reply-To: References: <20190808131448.349161-1-tmaimon77@gmail.com> <20190808131448.349161-3-tmaimon77@gmail.com> <20190808173232.4d79d698@collabora.com> Organization: Collabora X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-redhat-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 Fri, 9 Aug 2019 18:26:23 +0300 Tomer Maimon wrote: > Hi Boris, > > Thanks a lot for your comment. > > On Thu, 8 Aug 2019 at 18:32, Boris Brezillon > wrote: > > > On Thu, 8 Aug 2019 16:14:48 +0300 > > Tomer Maimon wrote: > > > > > > > + > > > +static const struct spi_controller_mem_ops npcm_fiu_mem_ops = { > > > + .exec_op = npcm_fiu_exec_op, > > > > No npcm_supports_op()? That's suspicious, especially after looking at > > the npcm_fiu_exec_op() (and the functions called from there) where the > > requested ->buswidth seems to be completely ignored... > > > > Sorry but I do not fully understand it, do you mean a support for the > buswidth? > If yes it been done in the UMA functions as follow: > > uma_cfg |= ilog2(op->cmd.buswidth); > uma_cfg |= ilog2(op->addr.buswidth) << > NPCM_FIU_UMA_CFG_ADBPCK_SHIFT; > uma_cfg |= ilog2(op->data.buswidth) << > NPCM_FIU_UMA_CFG_WDBPCK_SHIFT; > uma_cfg |= op->addr.nbytes << NPCM_FIU_UMA_CFG_ADDSIZ_SHIFT; > regmap_write(fiu->regmap, NPCM_FIU_UMA_ADDR, op->addr.val); > Hm, the default supports_op() implementation might be just fine for your use case. But there's one thing you still need to check: the number of addr cycles (or address size as you call it in this driver). Looks like your IP is limited to 4 address cycles, if I'm right, you should reject any operation that have op->addr.nbytes > 4. I also wonder if there's a limitation on the data size you can have on a single transfer. If there's one you should implement ->adjust_op() too.