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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 9E352C3A5A2 for ; Tue, 3 Sep 2019 14:20:50 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 6F6AD22D6D for ; Tue, 3 Sep 2019 14:20:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="FEFqSWTk"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="qO+VPZHZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6F6AD22D6D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.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:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version: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=iFLumI1fruwaWVPz9IuQALGdBIq7OEU18a+GNsj66jQ=; b=FEFqSWTkmPt7ls B7sBPrAU1d267zka69NwYLDnfxNXGlo7xkySERkbjNf6RwUfhqtXh1npDwTJdIMUJ1YAL6NFqt2BV UIY8s0H4YIG2yeI94XT3udB/8R3TGJ0fE8VyIGL3RjLArUJzW5AkYkrOSiVDyCRuhXWJDsADnMM4m VMBhXPx2++n4+IeYQyOX2VqNhmQDbQ6yoHw0cYGlBUpor0YHUJPY6QPnhhePTB/KS9Q3Z5bC936kM 5RknlHBx3tDtPbLOVyv8N3PI5t0sTQTc+oVyNsCd42s6oQ9yhjAFQon2XdnmV4pH/Rx20exiDkAvK B5FL2DUCht5g6cEzABEA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i59fr-00038T-4h; Tue, 03 Sep 2019 14:20:47 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i59fg-0002zM-7Y for linux-arm-kernel@lists.infradead.org; Tue, 03 Sep 2019 14:20:37 +0000 Received: from localhost.localdomain (cpe-70-114-128-244.austin.res.rr.com [70.114.128.244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8E2BE22D6D; Tue, 3 Sep 2019 14:20:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567520434; bh=ygZcufiEa4tPWQUTLwsIpxN5DMwkrJv3yH0ESnqY4bQ=; h=From:To:Cc:Subject:Date:From; b=qO+VPZHZBEPdHZs0lMom5N2QPKLnYZHR+43Y+b8JoVwKXDe/uARpF7uubMFjc/1zV W0nmnVF9tczCPEB3PoaGXpuF+4g66gM/IwLC9kQ4O4Q1oufMBr7bE5JQXCsDKDrojN YKD1RvVt8Uv2xoMWNmjE5BR9bH2BB8INavDEF33Y= From: Dinh Nguyen To: linux-kernel@vger.kernel.org Subject: [PATCHv7] drivers/amba: add reset control to amba bus probe Date: Tue, 3 Sep 2019 09:12:15 -0500 Message-Id: <20190903141215.18283-1-dinguyen@kernel.org> X-Mailer: git-send-email 2.20.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190903_072036_299188_035F5F86 X-CRM114-Status: GOOD ( 14.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: robh@kernel.org, daniel.thompson@linaro.org, tony.luck@intel.com, manivannan.sadhasivam@linaro.org, keescook@chromium.org, devicetree@vger.kernel.org, linus.walleij@linaro.org, anton@enomsg.org, linux@armlinux.org.uk, dinguyen@kernel.org, p.zabel@pengutronix.de, ccross@android.com, frowand.list@gmail.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org The primecell controller on some SoCs, i.e. SoCFPGA, is held in reset by default. Until recently, the DMA controller was brought out of reset by the bootloader(i.e. U-Boot). But a recent change in U-Boot, the peripherals that are not used are held in reset and are left to Linux to bring them out of reset. Add a mechanism for getting the reset property and de-assert the primecell module from reset if found. This is a not a hard fail if the reset properti is not present in the device tree node, so the driver will continue to probe. Because there are different variants of the controller that may have multiple reset signals, the code will find all reset(s) specified and de-assert them. Signed-off-by: Dinh Nguyen Reviewed-by: Rob Herring Reviewed-by: Philipp Zabel --- v7: added Philipp Zabel's Reviewed-by: v6: remove the need to reset_control_get_count as of_reset_control_array_get_optional_shared is already doing that v5: use of_reset_control_array_get_optional_shared() v4: cleaned up indentation in loop fix up a few checkpatch warnings add Reviewed-by: v3: add a reset_control_put() add error handling v2: move reset control to bus code find all reset properties and de-assert them --- drivers/amba/bus.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 100e798a5c82..f39f075abff9 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -18,6 +18,7 @@ #include #include #include +#include #include @@ -401,6 +402,19 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent) ret = amba_get_enable_pclk(dev); if (ret == 0) { u32 pid, cid; + struct reset_control *rstc; + + /* + * Find reset control(s) of the amba bus and de-assert them. + */ + rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node); + if (IS_ERR(rstc)) { + if (PTR_ERR(rstc) != -EPROBE_DEFER) + dev_err(&dev->dev, "Can't get amba reset!\n"); + return PTR_ERR(rstc); + } + reset_control_deassert(rstc); + reset_control_put(rstc); /* * Read pid and cid based on size of resource -- 2.20.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel