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authorSrinivas Kandagatla <srinivas.kandagatla@linaro.org>2018-02-15 12:25:09 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-05-30 07:50:48 +0200
commitcecf8a69042b3a54cb843223756c10ee8a8665e3 (patch)
tree8a99f645c2c0bea61d77b14ea0067de62e2a956f
parent086a52f1db8847dc0ab4acc5c9af3dd9cc4cf4e8 (diff)
dmaengine: qcom: bam_dma: get num-channels and num-ees from dt
[ Upstream commit 48d163b1aa6e7f650c0b7a4f9c61c387a6def868 ] When Linux is master of BAM, it can directly read registers to know number of supported channels, however when its remotely controlled reading these registers would trigger a crash if the BAM is not yet initialized or powered up on the remote side. This patch allows driver to read num-channels and num-ees from Device Tree for remotely controlled BAM. Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/dma/qcom/bam_dma.c27
1 files changed, 22 insertions, 5 deletions
diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
index 03c4eb3fd314..6497f5283e3b 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;
@@ -1076,15 +1077,19 @@ 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));
+ bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
+ }
/* check that configured EE is within range */
- if (bdev->ee >= val)
+ if (bdev->ee >= bdev->num_ees)
return -EINVAL;
- val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
- bdev->num_channels = val & BAM_NUM_PIPES_MASK;
+ if (!bdev->num_channels) {
+ val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
+ bdev->num_channels = val & BAM_NUM_PIPES_MASK;
+ }
if (bdev->controlled_remotely)
return 0;
@@ -1179,6 +1184,18 @@ static int bam_dma_probe(struct platform_device *pdev)
bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
"qcom,controlled-remotely");
+ if (bdev->controlled_remotely) {
+ ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
+ &bdev->num_channels);
+ if (ret)
+ dev_err(bdev->dev, "num-channels unspecified in dt\n");
+
+ ret = of_property_read_u32(pdev->dev.of_node, "qcom,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");
if (IS_ERR(bdev->bamclk))
return PTR_ERR(bdev->bamclk);