Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756670AbbLARac (ORCPT ); Tue, 1 Dec 2015 12:30:32 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:52759 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755546AbbLARa3 (ORCPT ); Tue, 1 Dec 2015 12:30:29 -0500 Date: Tue, 1 Dec 2015 11:30:26 -0600 From: Andy Gross To: Stanimir Varbanov Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, dmaengine@vger.kernel.org, Vinod Koul , Rob Herring , Rob Herring , Mark Rutland , Pawel Moll , Ian Campbell , Archit Taneja Subject: Re: [PATCH 4/4] dmaengine: qcom_bam_dma: add controlled remotely dt property Message-ID: <20151201173026.GD26687@Agamemnon.attlocal.net> References: <1448961299-15161-1-git-send-email-stanimir.varbanov@linaro.org> <1448961299-15161-5-git-send-email-stanimir.varbanov@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1448961299-15161-5-git-send-email-stanimir.varbanov@linaro.org> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2797 Lines: 72 On Tue, Dec 01, 2015 at 11:14:59AM +0200, Stanimir Varbanov wrote: > Some of the peripherals has bam which is controlled by remote > processor, thus the bam dma driver must avoid register writes > which initialise bam hw block. Those registers are protected > from xPU block and any writes to them will lead to secure > violation and system reboot. > > Adding the contolled_remotely flag in bam driver to avoid > not permitted register writes in bam_init function. > > Signed-off-by: Stanimir Varbanov > --- > .../devicetree/bindings/dma/qcom_bam_dma.txt | 2 ++ > drivers/dma/qcom_bam_dma.c | 7 +++++++ > 2 files changed, 9 insertions(+) > > diff --git a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt > index 1c9d48ea4914..87b6b2bf5e1e 100644 > --- a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt > +++ b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt > @@ -13,6 +13,8 @@ Required properties: > - clock-names: must contain "bam_clk" entry > - qcom,ee : indicates the active Execution Environment identifier (0-7) used in > the secure world. > +- qcom,controlled-remotely : optional, indicates that the bam is controled by > + remote proccessor i.e. execution enviroment. Please fix the spelling. controlled, environment. Otherwise looks ok. > > Example: > > diff --git a/drivers/dma/qcom_bam_dma.c b/drivers/dma/qcom_bam_dma.c > index 6d290de9ab2b..5dedab77180a 100644 > --- a/drivers/dma/qcom_bam_dma.c > +++ b/drivers/dma/qcom_bam_dma.c > @@ -387,6 +387,7 @@ struct bam_device { > > /* execution environment ID, from DT */ > u32 ee; > + bool controlled_remotely; > > const struct reg_offset_data *layout; > > @@ -1039,6 +1040,9 @@ static int bam_init(struct bam_device *bdev) > val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES)); > bdev->num_channels = val & BAM_NUM_PIPES_MASK; > > + if (bdev->controlled_remotely) > + return 0; > + > /* s/w reset bam */ > /* after reset all pipes are disabled and idle */ > val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL)); > @@ -1126,6 +1130,9 @@ static int bam_dma_probe(struct platform_device *pdev) > return ret; > } > > + bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node, > + "qcom,controlled-remotely"); > + > bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk"); > if (IS_ERR(bdev->bamclk)) > return PTR_ERR(bdev->bamclk); Reviewed-by: Andy Gross -- 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/