From mboxrd@z Thu Jan 1 00:00:00 1970 From: srinivas.kandagatla@linaro.org Subject: [PATCH 4/4] dmaengine: qcom: bam_dma: Add num-ees dt binding for remotely controlled Date: Tue, 16 Jan 2018 19:02:36 +0000 Message-ID: <20180116190236.14558-5-srinivas.kandagatla@linaro.org> References: <20180116190236.14558-1-srinivas.kandagatla@linaro.org> Return-path: In-Reply-To: <20180116190236.14558-1-srinivas.kandagatla@linaro.org> Sender: linux-arm-msm-owner@vger.kernel.org To: Vinod Koul , Andy Gross , dmaengine@vger.kernel.org Cc: Rob Herring , Mark Rutland , David Brown , Dan Williams , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, yanhe@quicinc.com, ramkri@qti.qualcomm.com, sdharia@quicinc.com, Srinivas Kandagatla List-Id: devicetree@vger.kernel.org From: Srinivas Kandagatla When Linux is master of BAM, it can directly read registers to know number of supported execution enviroments, however when its remotely controlled reading these registers would trigger a crash if the BAM is not yet intialized/powered up on the remote side. This patch adds new binding num-ees to specify supported number of Execution Environments when BAM is remotely controlled. Signed-off-by: Srinivas Kandagatla --- Documentation/devicetree/bindings/dma/qcom_bam_dma.txt | 2 ++ drivers/dma/qcom/bam_dma.c | 15 ++++++++++++--- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt index aa6822cbb230..f0d10c2b393e 100644 --- a/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt +++ b/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt @@ -17,6 +17,8 @@ Required properties: remote proccessor i.e. execution environment. - num-channels : optional, indicates supported number of DMA channels in a remotely controlled bam. +- num-ees : optional, indicates supported number of Execution Environments in a + remotely controlled bam. Example: diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index bbbb755d7549..7a8727271d60 100644 --- a/drivers/dma/qcom/bam_dma.c +++ b/drivers/dma/qcom/bam_dma.c @@ -387,6 +387,7 @@ struct bam_device { struct device_dma_parameters dma_parms; struct bam_chan *channels; u32 num_channels; + u32 num_ees; /* execution environment ID, from DT */ u32 ee; @@ -1079,11 +1080,14 @@ static int bam_init(struct bam_device *bdev) u32 val; /* read revision and configuration information */ - val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)) >> NUM_EES_SHIFT; - val &= NUM_EES_MASK; + if (!bdev->num_ees) { + val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)) >> NUM_EES_SHIFT; + val &= NUM_EES_MASK; + bdev->num_ees = val; + } /* check that configured EE is within range */ - if (bdev->ee >= val) + if (bdev->ee >= bdev->num_ees) return -EINVAL; if (!bdev->num_channels) { @@ -1189,6 +1193,11 @@ static int bam_dma_probe(struct platform_device *pdev) &bdev->num_channels); if (ret) dev_err(bdev->dev, "num-channels unspecified in dt\n"); + + ret = of_property_read_u32(pdev->dev.of_node, "num-ees", + &bdev->num_ees); + if (ret) + dev_err(bdev->dev, "num-ees unspecified in dt\n"); } bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk"); -- 2.15.1