Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760089AbcDEW5T (ORCPT ); Tue, 5 Apr 2016 18:57:19 -0400 Received: from mail-wm0-f49.google.com ([74.125.82.49]:32860 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759922AbcDEW5P (ORCPT ); Tue, 5 Apr 2016 18:57:15 -0400 From: Stanimir Varbanov To: Rob Herring , Mark Rutland , Vinod Koul , Andy Gross 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, Sinan Kaya , Pramod Gurav , Stanimir Varbanov Subject: [PATCH v2 3/5] dmaengine: qcom: bam_dma: add controlled remotely dt property Date: Wed, 6 Apr 2016 01:56:20 +0300 Message-Id: <1459896982-30171-4-git-send-email-stanimir.varbanov@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1459896982-30171-1-git-send-email-stanimir.varbanov@linaro.org> References: <1459896982-30171-1-git-send-email-stanimir.varbanov@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2303 Lines: 63 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 Reviewed-by: Andy Gross --- Documentation/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..9cbf5d9df8fd 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 controlled by + remote proccessor i.e. execution environment. Example: diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index 789d5f836bf7..d0f878a78fae 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; @@ -1042,6 +1043,9 @@ 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)); @@ -1129,6 +1133,9 @@ 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); -- 1.9.1