From patchwork Wed Aug 10 08:03:48 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guodong Xu X-Patchwork-Id: 9272803 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 73C72600CB for ; Wed, 10 Aug 2016 08:06:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 601F427C05 for ; Wed, 10 Aug 2016 08:06:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5247027D5E; Wed, 10 Aug 2016 08:06:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7087227C05 for ; Wed, 10 Aug 2016 08:06:27 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bXOVX-0001NV-LH; Wed, 10 Aug 2016 08:04:59 +0000 Received: from mail-pf0-x233.google.com ([2607:f8b0:400e:c00::233]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bXOV0-00010z-Ql for linux-arm-kernel@lists.infradead.org; Wed, 10 Aug 2016 08:04:29 +0000 Received: by mail-pf0-x233.google.com with SMTP id x72so13639064pfd.2 for ; Wed, 10 Aug 2016 01:04:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=nfSyP9hh+ZHNkGQk/FRRqhVBWHeYwaWnwMGCVvg3qOA=; b=JzdZGJ+qGRBi6TZx5MuB7NztcXOyVZpndU57mYx+GOCPZDajeYp4ZtkbZtU06Q4bPF UjxMC80bhYH+eQOrrX17U4eXv7DWDmc0HpMgyBuRzeAzmEpvmfbtmZQbc8ep2gomNiH1 8TEoasB1wCPPAId2+l/vOe2kg1LitWepynySI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=nfSyP9hh+ZHNkGQk/FRRqhVBWHeYwaWnwMGCVvg3qOA=; b=nCMrelvM1i5rmPym9HilC+HpIBKaC+9XgpGwTkzbdfz7SMUETy6l/8vbRBLU3dFCEN s8WxWYLYgMzcdIfV4P7Wm2R3W08T2OFxklQV+ANw2HpbQepzCnn9qW/yHAQQA3W6Tj9R W5W+s5B7/EsxaHnX/zlEmZkphaE1qd1ZZkj80PN4TCsfjVVzF7sUsgdq69x0/ridNTjX kTprnVRn34Knpr/a89nmv5yPXA1RuXiDfM7bw0LySTQ9LWugstJkJGeMuVQmS3hJaGT1 ZsOIT5YkD4ugpTzd/A7Ka5OTn8OXMSFHNPCHQop9/QbrG0gmF3CytJuY8VnGWS6u6II9 Q9+g== X-Gm-Message-State: AEkooutNs1q4yd/SwGi61nRMpmYib2TzYmOMt+7QYoMarWLLn+SHvUZn5bT3s8iiLVgrcPqc X-Received: by 10.98.80.220 with SMTP id g89mr4872698pfj.12.1470816245935; Wed, 10 Aug 2016 01:04:05 -0700 (PDT) Received: from localhost.localdomain ([45.56.159.82]) by smtp.gmail.com with ESMTPSA id 15sm61387706pfz.36.2016.08.10.01.04.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 10 Aug 2016 01:04:05 -0700 (PDT) From: Guodong Xu To: heiko@sntech.de, shawn.lin@rock-chips.com, jh80.chung@samsung.com, robh+dt@kernel.org, mark.rutland@arm.com, ulf.hansson@linaro.org, guodong.xu@linaro.org Subject: [PATCH v4 2/2] mmc: dw_mmc: add reset support to dwmmc host controller Date: Wed, 10 Aug 2016 16:03:48 +0800 Message-Id: <1470816228-8874-3-git-send-email-guodong.xu@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1470816228-8874-1-git-send-email-guodong.xu@linaro.org> References: <1470816228-8874-1-git-send-email-guodong.xu@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160810_010427_110443_74F5EDCB X-CRM114-Status: GOOD ( 15.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, Xinwei Kong , Zhangfei Gao , linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Dwmmc host controller may in unknown state when entering kernel boot. One example is when booting from eMMC, bootloader need initialize MMC host controller into some state so it can read. In order to make sure MMC host controller in a clean initial state, this reset support is added. With this patch, a 'resets' property can be added into dw_mmc device tree node. The hardware logic is: dwmmc host controller IP receives a reset signal from a 'reset provider' (eg. power management unit). The 'resets' property points to this reset signal. So, during dwmmc driver probe, it can use this signal to reset itself. Refer to [1] for more information. [1] Documentation/devicetree/bindings/reset/reset.txt Signed-off-by: Guodong Xu Signed-off-by: Xinwei Kong Signed-off-by: Zhangfei Gao Reviewed-by: Shawn Lin --- drivers/mmc/host/dw_mmc.c | 23 ++++++++++++++++++++++- include/linux/mmc/dw_mmc.h | 2 ++ 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 32380d5..481d441 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -2915,6 +2915,13 @@ static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host) if (!pdata) return ERR_PTR(-ENOMEM); + /* find reset controller when exist */ + pdata->rstc = devm_reset_control_get_optional(dev, NULL); + if (IS_ERR(pdata->rstc)) { + if (PTR_ERR(pdata->rstc) == -EPROBE_DEFER) + return ERR_PTR(-EPROBE_DEFER); + } + /* find out number of slots supported */ of_property_read_u32(np, "num-slots", &pdata->num_slots); @@ -2986,7 +2993,9 @@ int dw_mci_probe(struct dw_mci *host) if (!host->pdata) { host->pdata = dw_mci_parse_dt(host); - if (IS_ERR(host->pdata)) { + if (PTR_ERR(host->pdata) == -EPROBE_DEFER) { + return -EPROBE_DEFER; + } else if (IS_ERR(host->pdata)) { dev_err(host->dev, "platform data not available\n"); return -EINVAL; } @@ -3040,6 +3049,12 @@ int dw_mci_probe(struct dw_mci *host) } } + if (!IS_ERR(host->pdata->rstc)) { + reset_control_assert(host->pdata->rstc); + usleep_range(10, 50); + reset_control_deassert(host->pdata->rstc); + } + setup_timer(&host->cmd11_timer, dw_mci_cmd11_timer, (unsigned long)host); @@ -3189,6 +3204,9 @@ err_dmaunmap: if (host->use_dma && host->dma_ops->exit) host->dma_ops->exit(host); + if (!IS_ERR(host->pdata->rstc)) + reset_control_assert(host->pdata->rstc); + err_clk_ciu: if (!IS_ERR(host->ciu_clk)) clk_disable_unprepare(host->ciu_clk); @@ -3221,6 +3239,9 @@ void dw_mci_remove(struct dw_mci *host) if (host->use_dma && host->dma_ops->exit) host->dma_ops->exit(host); + if (!IS_ERR(host->pdata->rstc)) + reset_control_assert(host->pdata->rstc); + if (!IS_ERR(host->ciu_clk)) clk_disable_unprepare(host->ciu_clk); diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h index 83b0edfc..f5af2bd 100644 --- a/include/linux/mmc/dw_mmc.h +++ b/include/linux/mmc/dw_mmc.h @@ -17,6 +17,7 @@ #include #include #include +#include #define MAX_MCI_SLOTS 2 @@ -259,6 +260,7 @@ struct dw_mci_board { /* delay in mS before detecting cards after interrupt */ u32 detect_delay_ms; + struct reset_control *rstc; struct dw_mci_dma_ops *dma_ops; struct dma_pdata *data; };