[PATCH v2 2/2] dma: xilinx: Add reset support

[Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>]

Add a DT property to control an optional external reset line

Signed-off-by: Ramiro Oliveira <roliveir@synopsys.com>
---
 drivers/dma/xilinx/xilinx_dma.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 5c9f11b623ca..589cbb611bc8 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -32,20 +32,21 @@
  */
 
 #include <linux/bitops.h>
-#include <linux/dmapool.h>
+#include <linux/clk.h>
 #include <linux/dma/xilinx_dma.h>
+#include <linux/dmapool.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_dma.h>
-#include <linux/of_platform.h>
 #include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/reset.h>
 #include <linux/slab.h>
-#include <linux/clk.h>
-#include <linux/io-64-nonatomic-lo-hi.h>
 
 #include "../dmaengine.h"
 
@@ -409,6 +410,7 @@ struct xilinx_dma_device {
 	struct clk *rxs_clk;
 	u32 nr_channels;
 	u32 chan_id;
+	struct reset_control *rst;
 };
 
 /* Macros */
@@ -2543,6 +2545,20 @@ static int xilinx_dma_probe(struct platform_device *pdev)
 	if (IS_ERR(xdev->regs))
 		return PTR_ERR(xdev->regs);
 
+	xdev->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
+	if (IS_ERR(xdev->rst)) {
+		err = PTR_ERR(xdev->rst);
+		if (err == -EPROBE_DEFER)
+			return err;
+		xdev->rst = NULL;
+	} else {
+		err = reset_control_deassert(xdev->rst);
+		if (err) {
+			dev_err(xdev->dev, "error deasserting reset %d\n", err);
+			return err;
+		}
+	}
+
 	/* Retrieve the DMA engine properties from the device tree */
 	xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");
 	if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
-- 
2.11.0