Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754027AbbGTJds (ORCPT ); Mon, 20 Jul 2015 05:33:48 -0400 Received: from down.free-electrons.com ([37.187.137.238]:45614 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751612AbbGTJdq (ORCPT ); Mon, 20 Jul 2015 05:33:46 -0400 Date: Mon, 20 Jul 2015 11:33:43 +0200 From: Alexandre Belloni To: Josh Wu Cc: Nicolas Ferre , linux-arm-kernel@lists.infradead.org, Guenter Roeck , Kumar Gala , Ian Campbell , Rob Herring , Sebastian Reichel , Ben Dooks , Krzysztof Kozlowski , Pawel Moll , devicetree@vger.kernel.org, linux-pm@vger.kernel.org, Sudeep Holla , Wei Yongjun , Fabian Frederick , linux-kernel@vger.kernel.org, Boris Brezillon , Dmitry Eremin-Solenikov , David Woodhouse , Mark Rutland , Maxime Ripard Subject: Re: [PATCH v2 1/2] power: reset: at91: add sama5d3 reset function Message-ID: <20150720093343.GF15539@piout.net> References: <1437384726-24927-1-git-send-email-josh.wu@atmel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1437384726-24927-1-git-send-email-josh.wu@atmel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4387 Lines: 115 On 20/07/2015 at 17:32:05 +0800, Josh Wu wrote : > This patch introduces a new compatible string: "atmel,sama5d3-rstc" and > new reset function for sama5d3 and later chips. > > As in sama5d3 or later chips, we don't have to shutdown the DDR > controller before reset. Shutdown the DDR controller before reset is a > workaround to avoid DDR signal driving the bus, but since sama5d3 and > later chips there is no such a conflict. > > So in this patch: > 1. the sama5d3 reset function only need to write the rstc register > and return. > 2. we can remove the code related with sama5d3 DDR controller as > we don't use it at all. > > Signed-off-by: Josh Wu > Acked-by: Nicolas Ferre Acked-by: Alexandre Belloni > --- > > Changes in v2: > - aligned the function parameters to be consist with the coding style > - refined the commit log > - add binding document changes > - use of_device_is_compitable() instead > > .../devicetree/bindings/arm/atmel-at91.txt | 2 +- > drivers/power/reset/at91-reset.c | 26 ++++++++++++++++------ > 2 files changed, 20 insertions(+), 8 deletions(-) > > diff --git a/Documentation/devicetree/bindings/arm/atmel-at91.txt b/Documentation/devicetree/bindings/arm/atmel-at91.txt > index 424ac8c..dd998b9 100644 > --- a/Documentation/devicetree/bindings/arm/atmel-at91.txt > +++ b/Documentation/devicetree/bindings/arm/atmel-at91.txt > @@ -87,7 +87,7 @@ One interrupt per TC channel in a TC block: > > RSTC Reset Controller required properties: > - compatible: Should be "atmel,-rstc". > - can be "at91sam9260" or "at91sam9g45" > + can be "at91sam9260" or "at91sam9g45" or "sama5d3" > - reg: Should contain registers location and length > > Example: > diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c > index 36dc52f..c378d4e 100644 > --- a/drivers/power/reset/at91-reset.c > +++ b/drivers/power/reset/at91-reset.c > @@ -123,6 +123,15 @@ static int at91sam9g45_restart(struct notifier_block *this, unsigned long mode, > return NOTIFY_DONE; > } > > +static int sama5d3_restart(struct notifier_block *this, unsigned long mode, > + void *cmd) > +{ > + writel(cpu_to_le32(AT91_RSTC_KEY | AT91_RSTC_PERRST | AT91_RSTC_PROCRST), > + at91_rstc_base); > + > + return NOTIFY_DONE; > +} > + > static void __init at91_reset_status(struct platform_device *pdev) > { > u32 reg = readl(at91_rstc_base + AT91_RSTC_SR); > @@ -155,13 +164,13 @@ static void __init at91_reset_status(struct platform_device *pdev) > static const struct of_device_id at91_ramc_of_match[] = { > { .compatible = "atmel,at91sam9260-sdramc", }, > { .compatible = "atmel,at91sam9g45-ddramc", }, > - { .compatible = "atmel,sama5d3-ddramc", }, > { /* sentinel */ } > }; > > static const struct of_device_id at91_reset_of_match[] = { > { .compatible = "atmel,at91sam9260-rstc", .data = at91sam9260_restart }, > { .compatible = "atmel,at91sam9g45-rstc", .data = at91sam9g45_restart }, > + { .compatible = "atmel,sama5d3-rstc", .data = sama5d3_restart }, > { /* sentinel */ } > }; > > @@ -181,13 +190,16 @@ static int at91_reset_of_probe(struct platform_device *pdev) > return -ENODEV; > } > > - for_each_matching_node(np, at91_ramc_of_match) { > - at91_ramc_base[idx] = of_iomap(np, 0); > - if (!at91_ramc_base[idx]) { > - dev_err(&pdev->dev, "Could not map ram controller address\n"); > - return -ENODEV; > + if (!of_device_is_compatible(pdev->dev.of_node, "atmel,sama5d3-rstc")) { > + /* we need to shutdown the ddr controller, so get ramc base */ > + for_each_matching_node(np, at91_ramc_of_match) { > + at91_ramc_base[idx] = of_iomap(np, 0); > + if (!at91_ramc_base[idx]) { > + dev_err(&pdev->dev, "Could not map ram controller address\n"); > + return -ENODEV; > + } > + idx++; > } > - idx++; > } > > match = of_match_node(at91_reset_of_match, pdev->dev.of_node); > -- > 1.9.1 > -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/