From patchwork Fri Aug 12 08:51:26 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guodong Xu X-Patchwork-Id: 9276613 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 9696960752 for ; Fri, 12 Aug 2016 08:54:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8660128935 for ; Fri, 12 Aug 2016 08:54:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7B19728937; Fri, 12 Aug 2016 08:54:04 +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=unavailable 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 5629C28935 for ; Fri, 12 Aug 2016 08:54:03 +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 1bY8Cj-0005vu-7U; Fri, 12 Aug 2016 08:52:37 +0000 Received: from mail-pf0-x22e.google.com ([2607:f8b0:400e:c00::22e]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bY8CF-0005pQ-4c for linux-arm-kernel@lists.infradead.org; Fri, 12 Aug 2016 08:52:08 +0000 Received: by mail-pf0-x22e.google.com with SMTP id h186so7288563pfg.3 for ; Fri, 12 Aug 2016 01:51:46 -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=0p3SNtRKzs5R1Thg8zKTkYr60Z5XF5TCsDRfJw47ddU=; b=c8PuFowRfOen7hpgpmjL191LjAhCxknwXtODKurhgiUF05XQchNkGtI6WnqeRiepGU xHXeGw1sjeYDGut9bTVERKpB0lFYqgH3pKvrc+7EUsDyNx+tvJRouzmoehYknJb56W2m ANh5iTckZ2v5CgfUTQlD3jlnNkXH0G9O1v9no= 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=0p3SNtRKzs5R1Thg8zKTkYr60Z5XF5TCsDRfJw47ddU=; b=STEbYB3X50fSNd7tboQ9SV1qsehWVDJ0vnxSwDYjycKGcjlDx7f9WcXvfRVK770sAd 2T+iHG5+45xoADKRv18fen1PhRddNqETaXSySRwspGFZ/z59wtdAe/m96fBqU6PZjb+8 jr0IIdYpumQKK8pQf4inxuojhPzz3YbSsZpgZIVWtvpveDGRF3ahgF6Ytc7KIPmGYSbn wXngkBDXhBFob6uEhl1V/VIfFpIpy5IGNK6+HuJwIKGfl/dDUV5aiugEVjehMT4xerfr DmLmBPV0u+G5Ggg/SBTisZKU6c1WUyw2nS3mYaKL53e6e+5o2pRBJfkvvdjiUhCDAQrg NiWw== X-Gm-Message-State: AEkoousIGUoFW7DAP6TC+xao7uRYgJSK+HG2xLif2VZpawyXukidJqxElirA6xaqAdSGV1ZU X-Received: by 10.98.57.151 with SMTP id u23mr25317783pfj.4.1470991905561; Fri, 12 Aug 2016 01:51:45 -0700 (PDT) Received: from localhost.localdomain ([45.56.159.104]) by smtp.gmail.com with ESMTPSA id m128sm10988720pfm.42.2016.08.12.01.51.41 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 12 Aug 2016 01:51:45 -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 v5 2/2] mmc: dw_mmc: add reset support to dwmmc host controller Date: Fri, 12 Aug 2016 16:51:26 +0800 Message-Id: <1470991886-22412-3-git-send-email-guodong.xu@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1470991886-22412-1-git-send-email-guodong.xu@linaro.org> References: <1470991886-22412-1-git-send-email-guodong.xu@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160812_015207_250370_E5B8E8CF X-CRM114-Status: GOOD ( 15.46 ) 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 1b719a6..4dff0ee 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -2872,6 +2872,13 @@ 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); @@ -2943,7 +2950,9 @@ 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; } @@ -2997,6 +3006,12 @@ 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); @@ -3146,6 +3161,9 @@ 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: clk_disable_unprepare(host->ciu_clk); @@ -3176,6 +3194,9 @@ 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); + clk_disable_unprepare(host->ciu_clk); clk_disable_unprepare(host->biu_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; };