1 files changed, 38 insertions, 9 deletions

diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 3993ab65c62c..f06016d38a05 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -203,19 +203,27 @@ struct rcar_dmac {
 
 	unsigned int n_channels;
 	struct rcar_dmac_chan *channels;
-	unsigned int channels_mask;
+	u32 channels_mask;
 
 	DECLARE_BITMAP(modules, 256);
 };
 
 #define to_rcar_dmac(d)		container_of(d, struct rcar_dmac, engine)
 
+/*
+ * struct rcar_dmac_of_data - This driver's OF data
+ * @chan_offset_base: DMAC channels base offset
+ * @chan_offset_stride: DMAC channels offset stride
+ */
+struct rcar_dmac_of_data {
+	u32 chan_offset_base;
+	u32 chan_offset_stride;
+};
+
 /* -----------------------------------------------------------------------------
  * Registers
  */
 
-#define RCAR_DMAC_CHAN_OFFSET(i)	(0x8000 + 0x80 * (i))
-
 #define RCAR_DMAISTA			0x0020
 #define RCAR_DMASEC			0x0030
 #define RCAR_DMAOR			0x0060
@@ -1726,6 +1734,7 @@ static const struct dev_pm_ops rcar_dmac_pm = {
 
 static int rcar_dmac_chan_probe(struct rcar_dmac *dmac,
 				struct rcar_dmac_chan *rchan,
+				const struct rcar_dmac_of_data *data,
 				unsigned int index)
 {
 	struct platform_device *pdev = to_platform_device(dmac->dev);
@@ -1735,7 +1744,8 @@ static int rcar_dmac_chan_probe(struct rcar_dmac *dmac,
 	int ret;
 
 	rchan->index = index;
-	rchan->iomem = dmac->iomem + RCAR_DMAC_CHAN_OFFSET(index);
+	rchan->iomem = dmac->iomem + data->chan_offset_base +
+		       data->chan_offset_stride * index;
 	rchan->mid_rid = -EINVAL;
 
 	spin_lock_init(&rchan->lock);
@@ -1800,7 +1810,15 @@ static int rcar_dmac_parse_of(struct device *dev, struct rcar_dmac *dmac)
 		return -EINVAL;
 	}
 
+	/*
+	 * If the driver is unable to read dma-channel-mask property,
+	 * the driver assumes that it can use all channels.
+	 */
 	dmac->channels_mask = GENMASK(dmac->n_channels - 1, 0);
+	of_property_read_u32(np, "dma-channel-mask", &dmac->channels_mask);
+
+	/* If the property has out-of-channel mask, this driver clears it */
+	dmac->channels_mask &= GENMASK(dmac->n_channels - 1, 0);
 
 	return 0;
 }
@@ -1813,10 +1831,14 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 		DMA_SLAVE_BUSWIDTH_32_BYTES | DMA_SLAVE_BUSWIDTH_64_BYTES;
 	struct dma_device *engine;
 	struct rcar_dmac *dmac;
-	struct resource *mem;
+	const struct rcar_dmac_of_data *data;
 	unsigned int i;
 	int ret;
 
+	data = of_device_get_match_data(&pdev->dev);
+	if (!data)
+		return -EINVAL;
+
 	dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
 	if (!dmac)
 		return -ENOMEM;
@@ -1848,8 +1870,7 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	/* Request resources. */
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	dmac->iomem = devm_ioremap_resource(&pdev->dev, mem);
+	dmac->iomem = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(dmac->iomem))
 		return PTR_ERR(dmac->iomem);
 
@@ -1901,7 +1922,7 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 		if (!(dmac->channels_mask & BIT(i)))
 			continue;
 
-		ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i], i);
+		ret = rcar_dmac_chan_probe(dmac, &dmac->channels[i], data, i);
 		if (ret < 0)
 			goto error;
 	}
@@ -1948,8 +1969,16 @@ static void rcar_dmac_shutdown(struct platform_device *pdev)
 	rcar_dmac_stop_all_chan(dmac);
 }
 
+static const struct rcar_dmac_of_data rcar_dmac_data = {
+	.chan_offset_base = 0x8000,
+	.chan_offset_stride = 0x80,
+};
+
 static const struct of_device_id rcar_dmac_of_ids[] = {
-	{ .compatible = "renesas,rcar-dmac", },
+	{
+		.compatible = "renesas,rcar-dmac",
+		.data = &rcar_dmac_data,
+	},
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, rcar_dmac_of_ids);