[PATCH 1/2] dmaengine: pl08x: Release the reset before reading registers

[David Yang]

amba_read_periphid() happens to release the reset. A node that carries
arm,primecell-periphid never reaches it. Release the reset ourselves.

Signed-off-by: David Yang <mmyangfl@xxxxxxxxx>
---
 drivers/dma/amba-pl08x.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 543c2eb8cfa8..33ad6c42cd7f 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -75,6 +75,7 @@
 #include <linux/of.h>
 #include <linux/of_dma.h>
 #include <linux/pm_runtime.h>
+#include <linux/reset.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/amba/pl080.h>
@@ -2695,6 +2696,7 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 	struct pl08x_driver_data *pl08x;
 	struct vendor_data *vd = id->data;
 	struct device_node *np = adev->dev.of_node;
+	struct reset_control *rst;
 	u32 tsfr_size;
 	int ret = 0;
 	int i;
@@ -2725,6 +2727,16 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 		goto out_no_ioremap;
 	}
 
+	/* Release the reset before reading registers */
+	rst = devm_reset_control_get_optional_exclusive(&adev->dev, NULL);
+	if (IS_ERR(rst)) {
+		ret = PTR_ERR(rst);
+		goto out_no_ioremap;
+	}
+	ret = reset_control_deassert(rst);
+	if (ret)
+		goto out_no_ioremap;
+
 	if (vd->ftdmac020) {
 		u32 val;
 
-- 
2.53.0