From patchwork Tue Dec 10 09:14:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 181112 Delivered-To: patch@linaro.org Received: by 2002:ac9:44c4:0:0:0:0:0 with SMTP id t4csp5256356och; Tue, 10 Dec 2019 01:15:55 -0800 (PST) X-Google-Smtp-Source: APXvYqxK2W8rYUBSPtAT3aU9loXisexkLkHSSbQpeLg+Yu1up2/nGm1rssatVqJS5ZWp7Fw2lhwn X-Received: by 2002:a63:1c02:: with SMTP id c2mr23080856pgc.175.1575969354961; Tue, 10 Dec 2019 01:15:54 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1575969354; cv=none; d=google.com; s=arc-20160816; b=ilIGlb15Xi944TK9zQTJnLlagBzAbF++2Dhhgh720nMOvP643N4+g7R2T5Izx8Q4J2 j3cC9ASZQsfvqyjlLhUKQ4YLDaCvBUzw9tpz2V2Nem2pHmE8U2JXbeKKENEdrbOdyJLN oXldlJqiBEYD/Lmu+F0n/83OeIa0bE2KC4cduPeCoeTOzQJ5e8yzJYkq2bfpNe6TzJIr luhYN8a0ToDl5BVih3vXJJys9BdvTrDeoDci6bw4OfOT/1g4JxrsLL7D9OQWfvpBNCau GOTtrmOqV77UDdT/h7AfovFZq6qNjpTe8zcy+jguCF78shOq5A7pmuvMS8nqWHJXBpiZ 7jCA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=errors-to:sender:content-transfer-encoding:mime-version:cc :list-subscribe:list-help:list-post:list-archive:list-unsubscribe :list-id:precedence:message-id:date:subject:to:from:dkim-signature :dkim-filter:dkim-signature; bh=T1NyiMe8vlwo5Giyjw5iO8bgWDOEvfJGQ9YDUy4VMnw=; b=OG1NeoNfMwBTbgN53bTLfuxHq/23i+2JhWIHZMMKrOR5zX+3WUYTvIkdX9C/oGsb8I wzhHTkUmBf4P2UOqkOEzODuKdOT9+bb1Gpl/zgyr6cmMxu6+W89mX/FdSgjbeR2hlqQK OhzqhFjv8UsrPcfpDCPZIrklBfr75Xg2BXHnCQXw5B21Qvykjk+0MB630tkfqLCpBGaw YvUW/zUmHlugmTOIpW2iz7oyIo5rxrPMiRt7XJSL+KUx8bZ84KuisOvRSdRyKhWW6Un5 VYNvtVTZaIe6XWK2O7iTXhPEKE2iLW9S5hvTshcMYMSd3MbE819m94w8a7/8wjYViOpy fG/Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@lists.infradead.org header.s=bombadil.20170209 header.b=rjpHS2Gl; dkim=neutral (body hash did not verify) header.i=@nifty.com header.s=dec2015msa header.b=ZICkPQ0q; spf=pass (google.com: best guess record for domain of linux-mtd-bounces+patch=linaro.org@lists.infradead.org designates 2607:7c80:54:e::133 as permitted sender) smtp.mailfrom="linux-mtd-bounces+patch=linaro.org@lists.infradead.org" Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org. [2607:7c80:54:e::133]) by mx.google.com with ESMTPS id c4si2410414pgm.22.2019.12.10.01.15.54 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Dec 2019 01:15:54 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-mtd-bounces+patch=linaro.org@lists.infradead.org designates 2607:7c80:54:e::133 as permitted sender) client-ip=2607:7c80:54:e::133; Authentication-Results: mx.google.com; dkim=pass header.i=@lists.infradead.org header.s=bombadil.20170209 header.b=rjpHS2Gl; dkim=neutral (body hash did not verify) header.i=@nifty.com header.s=dec2015msa header.b=ZICkPQ0q; spf=pass (google.com: best guess record for domain of linux-mtd-bounces+patch=linaro.org@lists.infradead.org designates 2607:7c80:54:e::133 as permitted sender) smtp.mailfrom="linux-mtd-bounces+patch=linaro.org@lists.infradead.org" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=T1NyiMe8vlwo5Giyjw5iO8bgWDOEvfJGQ9YDUy4VMnw=; b=rjp HS2GlVB/WU6DLaO1hEPU+0D47sy1rlw/Pw5HWOuPHGWSpCsw58pZ0jFc6uUBuKoC3rCN3M6FHf73f kFtkBFKcyzBaJJhPw/mtATcvMaIRPbCIvAEoUgLBTs+pKXXOsSu2JUZNHcEnREPBDCxXVBiYjBK/f o2ab17a84y/n5sl6f4f3p6vA6DiwbM/VJE7xZ3oklirn70jxvaofpoRneDd4k4YELHC+uYLxEsrdu BsnPaISMDeait843f4I2fhguGRaoTlIHkVUGQvyBPUPUqZcGXHmnaU3GBO/TlEkJn8Eurk6pP1iQf fSR2zzTy0m9s+aZxW1hdSxDTpq0OBZw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iebcQ-0007mE-0P; Tue, 10 Dec 2019 09:15:46 +0000 Received: from conuserg-08.nifty.com ([210.131.2.75]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iebcM-0007kS-Ew for linux-mtd@lists.infradead.org; Tue, 10 Dec 2019 09:15:44 +0000 Received: from localhost.localdomain (p14092-ipngnfx01kyoto.kyoto.ocn.ne.jp [153.142.97.92]) (authenticated) by conuserg-08.nifty.com with ESMTP id xBA9F3nk002286; Tue, 10 Dec 2019 18:15:03 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-08.nifty.com xBA9F3nk002286 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1575969304; bh=fZSJ9406U2jMjTj0MJPsSAKAuiCbOY7z777j3BlnS64=; h=From:To:Cc:Subject:Date:From; b=ZICkPQ0qlKaZ5gvesye64Ajer4Y29LiQHJTthQMyXqWchv1Oz6XlkHQGYD46IHJVb oETXHqu+ORXaEeG2zHFMNaJ8eoHO2Vw5BKDohlNsjkKWCdgyYpZPX2e8Y5c05iVQ+J lpEEVP48mVGbii42pFZXO41SCVxny/qq5XKolD5ekOkNNKd+jsgDOFzwHfL46T1QbH EciXXoHdlaw8FYEn/Qg/Q4d4FhPPrRvw7TM4vumikxXMK6F/dUBL9xdOL3tkht9bc4 b+iqdsdNEcaOtiy//c13esKtEgHx/A0AvXUDXTgL4nXUWmmHGDA+5F6DeMQ94K1nGw HD1IxhqkAZl8Q== X-Nifty-SrcIP: [153.142.97.92] From: Masahiro Yamada To: linux-mtd@lists.infradead.org Subject: [PATCH] mtd: rawnand: denali: add reset controlling Date: Tue, 10 Dec 2019 18:14:53 +0900 Message-Id: <20191210091453.26346-1-yamada.masahiro@socionext.com> X-Mailer: git-send-email 2.17.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191210_011542_833081_E149FAEF X-CRM114-Status: GOOD ( 18.64 ) X-Spam-Score: 1.0 (+) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (1.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [210.131.2.75 listed in list.dnswl.org] 1.0 SPF_SOFTFAIL SPF: sender does not match SPF record (softfail) 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marek Vasut , Mark Rutland , Vignesh Raghavendra , Masahiro Yamada , Richard Weinberger , linux-kernel@vger.kernel.org, Ley Foon Tan , Dinh Nguyen , devicetree@vger.kernel.org, Rob Herring , Philipp Zabel , Miquel Raynal MIME-Version: 1.0 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+patch=linaro.org@lists.infradead.org According to the Denali User's Guide, this IP has two reset signals. rst_n: reset most of FFs in the controller core reg_rst_n: reset all FFs in the register interface, and in the initialization sequence This commit supports controlling those reset signals, although they might be often tied up together in actual SoC integration. One thing that should be kept in mind is the automated initialization sequence (a.k.a. 'bootstrap' process) is kicked off when reg_rst_n is deasserted. When the reset is deasserted, the controller issues a RESET command to the chip select 0, and attempts to read out the chip ID, and further more, ONFI parameters if it is an ONFI-compliant device. Then, the controller sets up the relevant registers based on the detected device parameters. This process is just redundant for Linux because nand_scan_ident() probes devices and sets up parameters accordingly. Rather, this hardware feature is annoying because it ends up with misdetection due to bugs. So, commit 0615e7ad5d52 ("mtd: nand: denali: remove Toshiba and Hynix specific fixup code") changed the driver to not rely on it. However, there is no way to prevent it from running. The IP provides the 'bootstrap_inhibit_init' port to suppress this sequence, but it is usually out of software control, and dependent on SoC implementation. As for the Socionext UniPhier platform, LD4 always enables it. For the later SoCs, the bootstrap sequence runs depending on the boot mode. I added usleep_range() to make the driver wait until the sequence finishes. Otherwise, the driver would fail to detect the chip due to the race between the driver and hardware-controlled sequence. Signed-off-by: Masahiro Yamada --- .../devicetree/bindings/mtd/denali-nand.txt | 7 ++++ drivers/mtd/nand/raw/denali_dt.c | 40 ++++++++++++++++++- 2 files changed, 46 insertions(+), 1 deletion(-) -- 2.17.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ diff --git a/Documentation/devicetree/bindings/mtd/denali-nand.txt b/Documentation/devicetree/bindings/mtd/denali-nand.txt index b32aed1db46d..a48b17fb969a 100644 --- a/Documentation/devicetree/bindings/mtd/denali-nand.txt +++ b/Documentation/devicetree/bindings/mtd/denali-nand.txt @@ -14,6 +14,11 @@ Required properties: interface clock, and the ECC circuit clock. - clock-names: should contain "nand", "nand_x", "ecc" +Optional properties: + - resets: may contain phandles to the controller core reset, the register + reset + - reset-names: may contain "nand", "reg" + Sub-nodes: Sub-nodes represent available NAND chips. @@ -46,6 +51,8 @@ nand: nand@ff900000 { reg-names = "nand_data", "denali_reg"; clocks = <&nand_clk>, <&nand_x_clk>, <&nand_ecc_clk>; clock-names = "nand", "nand_x", "ecc"; + resets = <&nand_rst>, <&nand_reg_rst>; + reset-names = "nand", "reg"; interrupts = <0 144 4>; nand@0 { diff --git a/drivers/mtd/nand/raw/denali_dt.c b/drivers/mtd/nand/raw/denali_dt.c index 8b779a899dcf..132bc6cc066c 100644 --- a/drivers/mtd/nand/raw/denali_dt.c +++ b/drivers/mtd/nand/raw/denali_dt.c @@ -6,6 +6,7 @@ */ #include +#include #include #include #include @@ -14,6 +15,7 @@ #include #include #include +#include #include "denali.h" @@ -22,6 +24,8 @@ struct denali_dt { struct clk *clk; /* core clock */ struct clk *clk_x; /* bus interface clock */ struct clk *clk_ecc; /* ECC circuit clock */ + struct reset_control *rst; /* core reset */ + struct reset_control *rst_reg; /* register reset */ }; struct denali_dt_data { @@ -151,6 +155,14 @@ static int denali_dt_probe(struct platform_device *pdev) if (IS_ERR(dt->clk_ecc)) return PTR_ERR(dt->clk_ecc); + dt->rst = devm_reset_control_get_optional_shared(dev, "nand"); + if (IS_ERR(dt->rst)) + return PTR_ERR(dt->rst); + + dt->rst_reg = devm_reset_control_get_optional_shared(dev, "reg"); + if (IS_ERR(dt->rst_reg)) + return PTR_ERR(dt->rst_reg); + ret = clk_prepare_enable(dt->clk); if (ret) return ret; @@ -166,10 +178,30 @@ static int denali_dt_probe(struct platform_device *pdev) denali->clk_rate = clk_get_rate(dt->clk); denali->clk_x_rate = clk_get_rate(dt->clk_x); - ret = denali_init(denali); + /* + * Deassert the register reset, and the core reset in this order. + * Deasserting the core reset while the register reset is asserted + * will cause unpredictable behavior in the controller. + */ + ret = reset_control_deassert(dt->rst_reg); if (ret) goto out_disable_clk_ecc; + ret = reset_control_deassert(dt->rst); + if (ret) + goto out_assert_rst_reg; + + /* + * When the reset is deasserted, the initialization sequence is kicked + * (bootstrap process). This will take a while, and the driver must + * wait until it finished in order to avoid unpredictable behavior. + */ + usleep_range(200, 1000); + + ret = denali_init(denali); + if (ret) + goto out_assert_rst; + for_each_child_of_node(dev->of_node, np) { ret = denali_dt_chip_init(denali, np); if (ret) { @@ -184,6 +216,10 @@ static int denali_dt_probe(struct platform_device *pdev) out_remove_denali: denali_remove(denali); +out_assert_rst: + reset_control_assert(dt->rst); +out_assert_rst_reg: + reset_control_assert(dt->rst_reg); out_disable_clk_ecc: clk_disable_unprepare(dt->clk_ecc); out_disable_clk_x: @@ -199,6 +235,8 @@ static int denali_dt_remove(struct platform_device *pdev) struct denali_dt *dt = platform_get_drvdata(pdev); denali_remove(&dt->controller); + reset_control_assert(dt->rst); + reset_control_assert(dt->rst_reg); clk_disable_unprepare(dt->clk_ecc); clk_disable_unprepare(dt->clk_x); clk_disable_unprepare(dt->clk);