[PATCH v4 13/20] dma: qcom: bam_dma: Add support to initialize interconnect path

[Bhupesh Sharma <bhupesh.sharma@linaro.org>]

From: Thara Gopinath <thara.gopinath@linaro.org>

BAM dma engine associated with certain hardware blocks could require
relevant interconnect pieces be initialized prior to the dma engine
initialization. For e.g. crypto bam dma engine on sm8250. Such requirement
is passed on to the bam dma driver from dt via the "interconnects"
property.  Add support in bam_dma driver to check whether the interconnect
path is accessible/enabled prior to attempting driver intializations.

Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
[Make header file inclusion alphabetical]
Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
---
 drivers/dma/qcom/bam_dma.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
index c8a77b428b52..fc84ef42507d 100644
--- a/drivers/dma/qcom/bam_dma.c
+++ b/drivers/dma/qcom/bam_dma.c
@@ -26,6 +26,7 @@
 #include <linux/kernel.h>
 #include <linux/io.h>
 #include <linux/init.h>
+#include <linux/interconnect.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
@@ -392,6 +393,7 @@ struct bam_device {
 	const struct reg_offset_data *layout;
 
 	struct clk *bamclk;
+	struct icc_path *mem_path;
 	int irq;
 
 	/* dma start transaction tasklet */
@@ -1284,9 +1286,18 @@ static int bam_dma_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	/* Ensure that interconnects are initialized */
+	bdev->mem_path = of_icc_get(bdev->dev, "memory");
+
+	if (IS_ERR(bdev->mem_path)) {
+		ret = PTR_ERR(bdev->mem_path);
+		dev_err(bdev->dev, "failed to acquire icc path %d\n", ret);
+		goto err_disable_clk;
+	}
+
 	ret = bam_init(bdev);
 	if (ret)
-		goto err_disable_clk;
+		goto err_icc_path_put;
 
 	tasklet_setup(&bdev->task, dma_tasklet);
 
@@ -1371,6 +1382,8 @@ static int bam_dma_probe(struct platform_device *pdev)
 		tasklet_kill(&bdev->channels[i].vc.task);
 err_tasklet_kill:
 	tasklet_kill(&bdev->task);
+err_icc_path_put:
+	icc_put(bdev->mem_path);
 err_disable_clk:
 	clk_disable_unprepare(bdev->bamclk);
 
@@ -1406,6 +1419,7 @@ static int bam_dma_remove(struct platform_device *pdev)
 
 	tasklet_kill(&bdev->task);
 
+	icc_put(bdev->mem_path);
 	clk_disable_unprepare(bdev->bamclk);
 
 	return 0;
-- 
2.31.1