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=-7.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 882EBC10F13 for ; Sun, 14 Apr 2019 17:51:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F0F220850 for ; Sun, 14 Apr 2019 17:51:48 +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="Sdjw4js9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726990AbfDNRvr (ORCPT ); Sun, 14 Apr 2019 13:51:47 -0400 Received: from mail-lj1-f195.google.com ([209.85.208.195]:35412 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725829AbfDNRvq (ORCPT ); Sun, 14 Apr 2019 13:51:46 -0400 Received: by mail-lj1-f195.google.com with SMTP id t4so4942604ljc.2 for ; Sun, 14 Apr 2019 10:51:44 -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=wDNbZFDfSFvMJbXwJGZWBP1FDY9RU5MYw0B/pPJFyO0=; b=Sdjw4js9kmZSBFAG+UQLVlJZJkpwtmFwxNY4QmvRZNZNewfETQxj8U3l4vSuo4Rr+M CPoLwCNW1piJq3tiQuSk6kmEsctA7L5w4eLtXXW240sQYuGkGBpcpPhWpQagS+14i2ZD po3TKPou6mDg64FZDp5beAQ4UVFBbRYC2d9+LSieBbJETXgUvvkpPX7nG8701k+aNm5x dGbkkfFyIwePxvwyKdd7btdbAPy3EfeG3QnNH+LHNcUH34j0KtlopLMR1ykOrcmO3GwP wEnzPOWeqhKrms2E6/VStkS18TcTvjttpT8dJkd032fEfq+pDhQzFIHJjHKkbHfWvsGU Btrw== 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=wDNbZFDfSFvMJbXwJGZWBP1FDY9RU5MYw0B/pPJFyO0=; b=VwMT5KmNEkpUTY7VkpvC+z/pvwquQxgihMgEw3NYRVVcCM8+SLYHO5fw4XJ0qjtmic 9Ao7PVMFySGez3OyxATaQ7ce1LE5VtYegKUfADedzYj6Yo15Mo+XjD/ob1gIyAVWakx6 5yoFPbqK+8YdWcuwsKiaWjDb3COJvXZti0YeiY5AiShwy+lza5O10Fm0aCJnW5q1RUgH mVWs9L2nBy+spZEoqhdSIaCQhlsKKFwA1TkeqgR2VzWsVZwoARaDgp55J2TTZZX7jZWS shaFQs/+q/u1J+G6zu71ZY0Dz1AwSmDFf1a8ve1pzmiK1K0upwlEaxg7NvOKW4xNZIQs 4TGw== X-Gm-Message-State: APjAAAXiFfEdxIwKCwvT6CZQkmGRA18rXmNqE4D0p8fllj7aXpgz3i+C 5an7K701WqJAEuX/aMnPyaP7bBQiZJw= X-Google-Smtp-Source: APXvYqx3R7LxyfpMUiIghvwGgEAAYM7RH/OvrfwCicN56t9hKHm34CxmmG8+DDut7lMASCdrqnJ4rQ== X-Received: by 2002:a2e:9194:: with SMTP id f20mr37118089ljg.10.1555264303718; Sun, 14 Apr 2019 10:51:43 -0700 (PDT) Received: from wasted.cogentembedded.com ([31.173.85.5]) by smtp.gmail.com with ESMTPSA id r19sm8644245lja.83.2019.04.14.10.51.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 14 Apr 2019 10:51:42 -0700 (PDT) Subject: Re: [PATCH v3 3/5] mtd: Add support for HyperBus memory devices To: Vignesh Raghavendra , David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Richard Weinberger , Rob Herring Cc: linux-mtd@lists.infradead.org, Tudor Ambarus , Miquel Raynal , Joakim Tjernlund , devicetree@vger.kernel.org, Mason Yang , linux-arm-kernel@lists.infradead.org, nsekhar@ti.com, linux-kernel@vger.kernel.org References: <20190412092923.24919-1-vigneshr@ti.com> <20190412092923.24919-4-vigneshr@ti.com> From: Sergei Shtylyov Organization: Cogent Embedded Message-ID: <53a92396-2535-ace7-3a31-1daf719ff323@cogentembedded.com> Date: Sun, 14 Apr 2019 20:51:40 +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: <20190412092923.24919-4-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 04/12/2019 12:29 PM, 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 wrt 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/Kconfig b/drivers/mtd/hyperbus/Kconfig > new file mode 100644 > index 000000000000..98147e28caa0 > --- /dev/null > +++ b/drivers/mtd/hyperbus/Kconfig > @@ -0,0 +1,11 @@ > +menuconfig MTD_HYPERBUS > + tristate "HyperBus support" > + select MTD_CFI > + select MTD_MAP_BANK_WIDTH_2 > + select MTD_CFI_AMDSTD > + select MTD_COMPLEX_MAPPINGS > + help > + This is the framework for the HyperBus which can be used by > + the HyperBus Controller driver to communicate with > + HyperFlash. See Cypress HyperBus specification for more > + details > diff --git a/drivers/mtd/hyperbus/Makefile b/drivers/mtd/hyperbus/Makefile > new file mode 100644 > index 000000000000..ca61dedd730d > --- /dev/null > +++ b/drivers/mtd/hyperbus/Makefile > @@ -0,0 +1,3 @@ > +# SPDX-License-Identifier: GPL-2.0 > + > +obj-$(CONFIG_MTD_HYPERBUS) += hyperbus-core.o > diff --git a/drivers/mtd/hyperbus/hyperbus-core.c b/drivers/mtd/hyperbus/hyperbus-core.c > new file mode 100644 > index 000000000000..49aeb59742c6 > --- /dev/null > +++ b/drivers/mtd/hyperbus/hyperbus-core.c > @@ -0,0 +1,192 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// > +// Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/ > +// Author: Vignesh Raghavendra [...] > +/* Default calibration routine for use by HyperBus controller. > + * Controller is calibrated by repeatedly reading known pattern ("QRY" > + * string from CFI space) > + * Lets ensure "QRY" string is read correctly at least 5 times to ensure > + * stability of the DLL lock. > + */ > +int hyperbus_calibrate(struct hyperbus_device *hbdev) > +{ > + struct map_info *map = &hbdev->map; > + struct cfi_private cfi; > + int count = HYPERBUS_CALIB_COUNT; > + int pass_count = 0; > + int ret; > + > + cfi.interleave = 1; > + cfi.device_type = CFI_DEVICETYPE_X16; > + cfi_send_gen_cmd(0xF0, 0, 0, map, &cfi, cfi.device_type, NULL); > + cfi_send_gen_cmd(0x98, 0x55, 0, map, &cfi, cfi.device_type, NULL); > + > + while (count--) { > + cfi_qry_present(map, 0, &cfi); > + ret = cfi_qry_present(map, 0, &cfi); Why call it twice in a row? > + if (ret) > + pass_count++; > + else > + pass_count = 0; > + if (pass_count == 5) > + break; > + } > + > + cfi_qry_mode_off(0, map, &cfi); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(hyperbus_calibrate); [...] > diff --git a/include/linux/mtd/hyperbus.h b/include/linux/mtd/hyperbus.h > new file mode 100644 > index 000000000000..19340cc56aa4 > --- /dev/null > +++ b/include/linux/mtd/hyperbus.h > @@ -0,0 +1,91 @@ [...] > +/** > + * hb_unregister_device - deregister HyperBus slave memory device You forgot to update the function name in the kernel-doc. :-) > + * @hbdev: hyperbus_device to be unregistered > + * > + * Return: 0 for success, others for failure. > + */ > +int hyperbus_unregister_device(struct hyperbus_device *hbdev); > + > +#endif /* __LINUX_MTD_HYPERBUS_H__ */ MBR, Sergei