[PATCH 2/2] dmaengine: pl08x: Use the channel count from the device tree

[David Yang <mmyangfl@gmail.com>]

The Hi3798MV100 DMAC is a plain PL080 except for the channel count: 4
instead of 8. The part ID does not say, and the driver takes the count
from the matched vendor_data entry. dma-common.yaml already defines
dma-channels for a controller node. Honor it.

Signed-off-by: David Yang <mmyangfl@gmail.com>
---
 drivers/dma/amba-pl08x.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 33ad6c42cd7f..9bcb4a3cd5a0 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -2698,6 +2698,7 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 	struct device_node *np = adev->dev.of_node;
 	struct reset_control *rst;
 	u32 tsfr_size;
+	u32 channels;
 	int ret = 0;
 	int i;
 
@@ -2759,6 +2760,16 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 		vd->dualmaster = !!(val & BIT(9));
 	}
 
+	/* Read the channel number from the node if specified */
+	if (!of_property_read_u32(np, "dma-channels", &channels) && channels) {
+		if (channels > vd->channels)
+			dev_warn(&adev->dev,
+				 "using %u channels, instead of %u from the node\n",
+				 vd->channels, channels);
+		else
+			vd->channels = channels;
+	}
+
 	/* Initialize memcpy engine */
 	dma_cap_set(DMA_MEMCPY, pl08x->memcpy.cap_mask);
 	pl08x->memcpy.dev = &adev->dev;
-- 
2.53.0