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=-8.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 D016AC742A2 for ; Thu, 11 Jul 2019 19:26:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A132A20872 for ; Thu, 11 Jul 2019 19:26:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cogentembedded-com.20150623.gappssmtp.com header.i=@cogentembedded-com.20150623.gappssmtp.com header.b="SEuD7woY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728730AbfGKT0c (ORCPT ); Thu, 11 Jul 2019 15:26:32 -0400 Received: from mail-lj1-f193.google.com ([209.85.208.193]:41189 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728102AbfGKT0b (ORCPT ); Thu, 11 Jul 2019 15:26:31 -0400 Received: by mail-lj1-f193.google.com with SMTP id d24so6939798ljg.8 for ; Thu, 11 Jul 2019 12:26:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cogentembedded-com.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:organization:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=1Gj/TpYGciG5OCmfbf2dVn6FNmz3afk+DosbRV4MzoY=; b=SEuD7woYh9OiLSQ1qqz/ru6e3z42i2sBTpzp8MOwXfr7/I//sRjs+uMPX7Uo/WUtIs +AwJVNrx3GqT2kwzv3pSL+VHr0NLxNPaFkjII1VDIRgs99twXT0eBytNhdx/yFwvy2lN hqE6hLa4AwQSyZ5Uq5JGDUvkqjBS3OnLM/mNEAo7yqYb/bJSDeDx1HqZ1OWLN/QIHvJC oZc12rA0Jp/ZDSkfpQDwufjD9Zu66J8QqnnlIo5Rk+H3P9eR8IQ0xYVMoO97sTQW4Xbe 3Ui0eh2fGCWuhxiRNtCiD29GEt8YFc4IsNdQiPVoehP3xpWACHJpaHEn9OCeYUOOlCKE mTnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:organization :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=1Gj/TpYGciG5OCmfbf2dVn6FNmz3afk+DosbRV4MzoY=; b=OSMMl52gK1t/aD024bEkww1T3q93L9xu6czML1e/Z8Cczds5zH7NdAcYqQTdvwW9iO V2qS0P24ZGll0CoSzVErNlZj4azITbB4sSSSYHCKIW0ODeQvLj1o3h1GDwXQS6SALWB4 pB1T2ULXaTSmcwkleHMfHYxh+Ndh4s6ZWIQu8KFftMF7tGeQzmN8CqTwTbOsDz0ag3nV w1p9zidvA9qipH84N/a4ZyygqgYjRvfiZxM9AHTDvPgF0VRLyJYz0RfH/j8AaqY7uwVZ ErMmuiQRiTjbpykieqEJcDYoemo+jpDjWIxsLBU38qTumf4/hVCu25ZSz8zR9ftzYTN8 /ahg== X-Gm-Message-State: APjAAAWuX+Kq+8vVKLUjEARf9opar830+2M08Sf2QXh/wGDGF4MIFoIb GIZxFZVD8NQzEEmcaPw2WXrJQQ== X-Google-Smtp-Source: APXvYqw0NR2+TFc5SfbPRhU4TviTWXjU5RRXRUxYbST9Ry9aqWtbT5Ta93nbQMGF/Y7Ssa+Uh36+Fg== X-Received: by 2002:a2e:9b84:: with SMTP id z4mr3542327lji.75.1562873189537; Thu, 11 Jul 2019 12:26:29 -0700 (PDT) Received: from wasted.cogentembedded.com ([2a00:1fa0:6a9:2c74:93e5:edca:9c98:290d]) by smtp.gmail.com with ESMTPSA id j14sm1122764ljc.67.2019.07.11.12.26.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 11 Jul 2019 12:26:28 -0700 (PDT) Subject: Re: [PATCH v8 3/5] mtd: Add support for HyperBus memory devices To: Vignesh Raghavendra , Boris Brezillon , Marek Vasut , Richard Weinberger , Rob Herring Cc: linux-mtd@lists.infradead.org, Miquel Raynal , devicetree@vger.kernel.org, Mason Yang , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Tokunori Ikegami References: <20190625075746.10439-1-vigneshr@ti.com> <20190625075746.10439-4-vigneshr@ti.com> From: Sergei Shtylyov Organization: Cogent Embedded Message-ID: Date: Thu, 11 Jul 2019 22:26:27 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20190625075746.10439-4-vigneshr@ti.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-MW Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello! On 06/25/2019 10:57 AM, Vignesh Raghavendra wrote: > Cypress' HyperBus is Low Signal Count, High Performance Double Data Rate > Bus interface between a host system master and one or more slave > interfaces. HyperBus is used to connect microprocessor, microcontroller, > or ASIC devices with random access NOR flash memory (called HyperFlash) > or self refresh DRAM (called HyperRAM). > > Its a 8-bit data bus (DQ[7:0]) with Read-Write Data Strobe (RWDS) > signal and either Single-ended clock(3.0V parts) or Differential clock > (1.8V parts). It uses ChipSelect lines to select b/w multiple slaves. > At bus level, it follows a separate protocol described in HyperBus > specification[1]. > > HyperFlash follows CFI AMD/Fujitsu Extended Command Set (0x0002) similar > to that of existing parallel NORs. Since HyperBus is x8 DDR bus, > its equivalent to x16 parallel NOR flash with respect to bits per clock > cycle. But HyperBus operates at >166MHz frequencies. > HyperRAM provides direct random read/write access to flash memory > array. > > But, HyperBus memory controllers seem to abstract implementation details > and expose a simple MMIO interface to access connected flash. > > Add support for registering HyperFlash devices with MTD framework. MTD > maps framework along with CFI chip support framework are used to support > communicating with flash. > > Framework is modelled along the lines of spi-nor framework. HyperBus > memory controller (HBMC) drivers calls hyperbus_register_device() to > register a single HyperFlash device. HyperFlash core parses MMIO access > information from DT, sets up the map_info struct, probes CFI flash and > registers it with MTD framework. > > Some HBMC masters need calibration/training sequence[3] to be carried > out, in order for DLL inside the controller to lock, by reading a known > string/pattern. This is done by repeatedly reading CFI Query > Identification String. Calibration needs to be done before trying to detect > flash as part of CFI flash probe. > > HyperRAM is not supported at the moment. > > HyperBus specification can be found at[1] > HyperFlash datasheet can be found at[2] > > [1] https://www.cypress.com/file/213356/download > [2] https://www.cypress.com/file/213346/download > [3] http://www.ti.com/lit/ug/spruid7b/spruid7b.pdf > Table 12-5741. HyperFlash Access Sequence > > Signed-off-by: Vignesh Raghavendra [...] > diff --git a/drivers/mtd/hyperbus/hyperbus-core.c b/drivers/mtd/hyperbus/hyperbus-core.c > new file mode 100644 > index 000000000000..63a9e64895bc > --- /dev/null > +++ b/drivers/mtd/hyperbus/hyperbus-core.c > @@ -0,0 +1,154 @@ [...] > +int hyperbus_register_device(struct hyperbus_device *hbdev) > +{ [...] > + map->name = dev_name(dev); > + map->bankwidth = 2; I think this should really be 1, judging on the comment to that field (and on Cogent's own RPC-IF HF driver). > + map->device_node = np; [...] MBR, Sergei