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=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 43404C3A59F for ; Mon, 26 Aug 2019 15:52:05 +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 158CD2173E for ; Mon, 26 Aug 2019 15:52:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="uV7LVSfz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 158CD2173E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de 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:References:In-Reply-To: Date:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=eFwSe/+bnyez5VDTBFBnr6irfvqBpjQs8xIycwAs6Ro=; b=uV7LVSfzWFMfpm 5pDM24T05eehURLCEIAZFvpdoHQkLOj3I7Mk5hxKCi3xnLO7iKIwOZPx10rKj4389mGhPC6M9ouY1 +ocwcOZeafRu7Ac6l+JmKKcjtiRKtF8TAegiNYZje3NfFO2S0zwDz9eAra+IcFRBxQqRkIxI0nByN DoW5q24+S6/rxsqe4SFBTe4jOJrxA2dt/xHRccPHO9oQWG/uzfO4apd/vK4QQHxQ95GZArl7vw4M1 BaV1+I2JwuDsqrcfvq33plZAnyfwbYQLw39BcKAOQ15oQX3amJxM5zU1x7oNmqKDN9qNOVdxbqj0T 4J9EWzV5jug2bI8oWBHg==; 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 1i2HHj-0003Wl-HR; Mon, 26 Aug 2019 15:51:59 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i2HHf-0003W7-Pc for linux-arm-kernel@lists.infradead.org; Mon, 26 Aug 2019 15:51:57 +0000 Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1i2HHW-0007Po-QI; Mon, 26 Aug 2019 17:51:46 +0200 Message-ID: <1566834704.3842.7.camel@pengutronix.de> Subject: Re: [PATCHv5] drivers/amba: add reset control to amba bus probe From: Philipp Zabel To: Dinh Nguyen , linux-kernel@vger.kernel.org Date: Mon, 26 Aug 2019 17:51:44 +0200 In-Reply-To: <20190826154252.22952-1-dinguyen@kernel.org> References: <20190826154252.22952-1-dinguyen@kernel.org> X-Mailer: Evolution 3.22.6-1+deb9u2 Mime-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:3ad5:47ff:feaf:1a17 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190826_085155_834539_31332DF4 X-CRM114-Status: GOOD ( 20.82 ) 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: devicetree@vger.kernel.org, daniel.thompson@linaro.org, tony.luck@intel.com, manivannan.sadhasivam@linaro.org, keescook@chromium.org, robh@kernel.org, linus.walleij@linaro.org, anton@enomsg.org, linux@armlinux.org.uk, 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 On Mon, 2019-08-26 at 10:42 -0500, Dinh Nguyen wrote: > 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 > --- > 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 | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c > index 100e798a5c82..f8a7cb74c3cf 100644 > --- a/drivers/amba/bus.c > +++ b/drivers/amba/bus.c > @@ -18,6 +18,7 @@ > #include > #include > #include > +#include > > #include > > @@ -401,6 +402,24 @@ 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; > + int count; > + struct reset_control *rstc; > + > + /* > + * Find reset control(s) of the amba bus and de-assert them. > + */ > + count = reset_control_get_count(&dev->dev); > + while (count > 0) { > + rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node); You can drop the loop, the rstc returned by of_reset_control_array_get() already controls all resets together. regards Philipp _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Subject: Re: [PATCHv5] drivers/amba: add reset control to amba bus probe Date: Mon, 26 Aug 2019 17:51:44 +0200 Message-ID: <1566834704.3842.7.camel@pengutronix.de> References: <20190826154252.22952-1-dinguyen@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190826154252.22952-1-dinguyen@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Dinh Nguyen , linux-kernel@vger.kernel.org Cc: devicetree@vger.kernel.org, robh@kernel.org, linux@armlinux.org.uk, frowand.list@gmail.com, keescook@chromium.org, anton@enomsg.org, ccross@android.com, tony.luck@intel.com, daniel.thompson@linaro.org, linus.walleij@linaro.org, manivannan.sadhasivam@linaro.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Mon, 2019-08-26 at 10:42 -0500, Dinh Nguyen wrote: > 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 > --- > 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 | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c > index 100e798a5c82..f8a7cb74c3cf 100644 > --- a/drivers/amba/bus.c > +++ b/drivers/amba/bus.c > @@ -18,6 +18,7 @@ > #include > #include > #include > +#include > > #include > > @@ -401,6 +402,24 @@ 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; > + int count; > + struct reset_control *rstc; > + > + /* > + * Find reset control(s) of the amba bus and de-assert them. > + */ > + count = reset_control_get_count(&dev->dev); > + while (count > 0) { > + rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node); You can drop the loop, the rstc returned by of_reset_control_array_get() already controls all resets together. regards Philipp