[PATCH 2/2] xilinx_dma: Add reset support

[Ramiro Oliveira]

Add a DT property to control an optional external reset line

Signed-off-by: Ramiro Oliveira <roliv...@synopsys.com>
---
 drivers/dma/xilinx/xilinx_dma.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 5c9f11b..b845224 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -46,6 +46,7 @@
 #include <linux/slab.h>
 #include <linux/clk.h>
 #include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/reset.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 +2545,27 @@ 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(&pdev->dev, "reset");
+       if (IS_ERR(xdev->rst)) {
+               err = PTR_ERR(xdev->rst);
+               switch (err) {
+               case -ENOENT:
+               case -ENOTSUPP:
+                       xdev->rst = NULL;
+               break;
+               default:
+                       dev_err(xdev->dev, "error getting reset %d\n", err);
+               return err;
+               }
+       } else {
+               err = reset_control_deassert(xdev->rst);
+               if (err) {
+                       dev_err(xdev->dev, "failed to deassert 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)
-- 
2.10.2