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=-17.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 CF084C433DB for ; Mon, 22 Mar 2021 18:22:32 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4B97661983 for ; Mon, 22 Mar 2021 18:22:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B97661983 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=walle.cc Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=x1WsiTp4qRhp4Fj9tOAPF16FFX2paaBjYhAnHbx0w38=; b=aCtzSvefxg+WYJdXgNv2KusPT WOYC2VwDuNNPV0I5TVTKHXkgM/heQK+7cOuyzauPRftkXkvgQmPEVJACRzhCcbf7RLPjrei8yZ4LV GzXjpU3NrZP8ONoK4w2bSfFVZqWDF1K0i36/jF/nVmW6PI8QCRfKb+Jae1CKKwCZrOlNl1VXfBX5N E869iLQasNWhx6SgK7JbtckUnVxKKpPaWwm/IVdC2NacobP1YYFHkFIqXuPoYGEPzWqP1zDhiJ4gV +hWcS3EuRTHek2xqXlwOIhioC9BxaXYK2oXhoVHuINTiPJ8scgaOmCTdFXkXGY73ovpe9pWr36b+N xAyZOCkWA==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lOPB4-00CF1L-3i; Mon, 22 Mar 2021 18:21:22 +0000 Received: from ssl.serverraum.org ([176.9.125.105]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lOP9x-00CEja-Hd for linux-mtd@lists.infradead.org; Mon, 22 Mar 2021 18:20:15 +0000 Received: from mwalle01.fritz.box (unknown [IPv6:2a02:810c:c200:2e91:fa59:71ff:fe9b:b851]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id 58DF322255; Mon, 22 Mar 2021 19:20:10 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1616437210; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9KjLV5Ka9bey5dKJWPzgAenJL/VH5mtWkQstrGXp430=; b=G3z7uufUUt2D4bHIAoA4KFcAr3mhdhx0PHU/l3H/v7it49QhCW3A5oNbPGULPE3Xn0vPOl D1l926b4w4CZVGDh/qOyWXc3pSs6d3t0QBYW+fXaOOmpxIQV/HOe7RNT9AiGwor5oBwNXs G5l1ZAha5g177tWwp/hPEtQdJobYqfg= From: Michael Walle To: linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Rob Herring , Srinivas Kandagatla , =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= , Michael Walle Subject: [RFC PATCH 4/4] mtd: core: add OTP nvmem provider support Date: Mon, 22 Mar 2021 19:19:49 +0100 Message-Id: <20210322181949.2805-5-michael@walle.cc> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210322181949.2805-1-michael@walle.cc> References: <20210322181949.2805-1-michael@walle.cc> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210322_182013_895341_BD6DF8BF X-CRM114-Status: GOOD ( 22.37 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org Flash OTP regions can already be read via user space. Some boards have their serial number or MAC addresses stored in the OTP regions. Add support for them being a (read-only) nvmem provider. The API to read the OTP data is already in place. It distinguishes between factory and user OTP, thus there are up to two different providers. Signed-off-by: Michael Walle --- drivers/mtd/mtdcore.c | 149 ++++++++++++++++++++++++++++++++++++++++ include/linux/mtd/mtd.h | 2 + 2 files changed, 151 insertions(+) diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index 432769caae04..300340973561 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -776,6 +776,147 @@ static void mtd_set_dev_defaults(struct mtd_info *mtd) mutex_init(&mtd->master.chrdev_lock); } +static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user) +{ + struct otp_info *info = kmalloc(PAGE_SIZE, GFP_KERNEL); + ssize_t size = 0; + unsigned int i; + size_t retlen; + int ret; + + if (is_user) + ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info); + else + ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info); + if (ret) + goto err; + + for (i = 0; i < retlen / sizeof(*info); i++) { + size += info->length; + info++; + } + + kfree(info); + return size; + +err: + kfree(info); + return ret; +} + +static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd, + const char *name, int size, + nvmem_reg_read_t reg_read, + const char *compatible) +{ + struct nvmem_device *nvmem = NULL; + struct nvmem_config config = {}; + struct device_node *np; + + /* DT binding is optional */ + np = of_get_compatible_child(mtd->dev.of_node, compatible); + + /* OTP nvmem will be registered on the physical device */ + config.dev = mtd->dev.parent; + config.name = name; + config.id = NVMEM_DEVID_NONE; + config.owner = THIS_MODULE; + config.type = NVMEM_TYPE_OTP; + config.root_only = true; + config.reg_read = reg_read; + config.size = size; + config.of_node = np; + config.priv = mtd; + + nvmem = nvmem_register(&config); + /* Just ignore if there is no NVMEM support in the kernel */ + if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP) + nvmem = NULL; + + of_node_put(np); + + return nvmem; +} + +static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset, + void *val, size_t bytes) +{ + struct mtd_info *mtd = priv; + size_t retlen; + int ret; + + ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val); + if (ret) + return ret; + + return retlen == bytes ? 0 : -EIO; +} + +static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset, + void *val, size_t bytes) +{ + struct mtd_info *mtd = priv; + size_t retlen; + int ret; + + ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val); + if (ret) + return ret; + + return retlen == bytes ? 0 : -EIO; +} + +static int mtd_otp_nvmem_add(struct mtd_info *mtd) +{ + struct nvmem_device *nvmem; + ssize_t size; + int err; + + if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) { + size = mtd_otp_size(mtd, true); + if (size < 0) + return size; + + if (size > 0) { + nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size, + mtd_nvmem_user_otp_reg_read, + "mtd-user-otp"); + if (IS_ERR(nvmem)) { + dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n"); + return PTR_ERR(nvmem); + } + mtd->otp_user_nvmem = nvmem; + } + } + + if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) { + size = mtd_otp_size(mtd, false); + if (size < 0) { + err = size; + goto err; + } + + if (size > 0) { + nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size, + mtd_nvmem_fact_otp_reg_read, + "mtd-factory-otp"); + if (IS_ERR(nvmem)) { + dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n"); + err = PTR_ERR(nvmem); + goto err; + } + mtd->otp_factory_nvmem = nvmem; + } + } + + return 0; + +err: + if (mtd->otp_user_nvmem) + nvmem_unregister(mtd->otp_user_nvmem); + return err; +} + /** * mtd_device_parse_register - parse partitions and register an MTD device. * @@ -851,6 +992,8 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types, register_reboot_notifier(&mtd->reboot_notifier); } + ret = mtd_otp_nvmem_add(mtd); + out: if (ret && device_is_registered(&mtd->dev)) del_mtd_device(mtd); @@ -872,6 +1015,12 @@ int mtd_device_unregister(struct mtd_info *master) if (master->_reboot) unregister_reboot_notifier(&master->reboot_notifier); + if (master->otp_user_nvmem) + nvmem_unregister(master->otp_user_nvmem); + + if (master->otp_factory_nvmem) + nvmem_unregister(master->otp_factory_nvmem); + err = del_mtd_partitions(master); if (err) return err; diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h index 4aac200ca8b5..71e751d18c22 100644 --- a/include/linux/mtd/mtd.h +++ b/include/linux/mtd/mtd.h @@ -379,6 +379,8 @@ struct mtd_info { int usecount; struct mtd_debug_info dbg; struct nvmem_device *nvmem; + struct nvmem_device *otp_user_nvmem; + struct nvmem_device *otp_factory_nvmem; /* * Parent device from the MTD partition point of view. -- 2.20.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/