[PATCH 3/8] dma: mmp_pdma: Add optional reset controller support

Guodong Xu
2025-06-11T12:59:52Z

Add support for hardware reset control in the MMP PDMA driver using the
devm_reset_control_get_optional_exclusive_deasserted() API.

The reset controller is retrieved without a specific reset name,
allowing platforms to define a single default reset line for the
PDMA controller.

Signed-off-by: Guodong Xu <guodong@riscstar.com>
---
drivers/dma/mmp_pdma.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c
index 4a6dbf558237..fe627efeaff0 100644
--- a/drivers/dma/mmp_pdma.c
+++ b/drivers/dma/mmp_pdma.c
@@ -16,6 +16,7 @@
#include <linux/platform_data/mmp_dma.h>
#include <linux/dmapool.h>
#include <linux/clk.h>
+#include <linux/reset.h>
#include <linux/of_dma.h>
#include <linux/of.h>

@@ -1021,6 +1022,7 @@ static int mmp_pdma_probe(struct platform_device *op)
struct mmp_pdma_device *pdev;
struct mmp_dma_platdata *pdata = dev_get_platdata(&op->dev);
struct clk *clk;
+ struct reset_control *rst;
int i, ret, irq = 0;
int dma_channels = 0, irq_num = 0;
const enum dma_slave_buswidth widths =
@@ -1043,6 +1045,11 @@ static int mmp_pdma_probe(struct platform_device *op)
if (IS_ERR(clk))
return PTR_ERR(clk);

+ rst = devm_reset_control_get_optional_exclusive_deasserted(pdev->dev,
+ NULL);
+ if (IS_ERR(rst))
+ return PTR_ERR(rst);
+
if (pdev->dev->of_node) {
/* Parse new and deprecated dma-channels properties */
if (of_property_read_u32(pdev->dev->of_node, "dma-channels",
--
2.43.0