dmaengine: dw: define DW_DMA_MAX_NR_MASTERS

Instead of using magic number in the code the patch provides
DW_DMA_MAX_NR_MASTERS constant.

While here, restrict the reading of data width array by amount of the actual
number of AHB masters.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Documentation/devicetree/bindings/dma/snps-dma.txt

@@ -38,7 +38,7 @@ Example:
 		chan_allocation_order = <1>;
 		chan_priority = <1>;
 		block_size = <0xfff>;
-		data_width = <3 3 0 0>;
+		data_width = <3 3>;
 	};
 
 DMA clients connected to the Designware DMA controller must use the format

arch/arc/boot/dts/abilis_tb10x.dtsi

@@ -112,7 +112,7 @@
 			chan_allocation_order = <0>;
 			chan_priority = <1>;
 			block_size = <0x7ff>;
-			data_width = <2 0 0 0>;
+			data_width = <2>;
 			clocks = <&ahb_clk>;
 			clock-names = "hclk";
 		};

arch/arm/boot/dts/spear13xx.dtsi

@@ -117,7 +117,7 @@
 			chan_priority = <1>;
 			block_size = <0xfff>;
 			dma-masters = <2>;
-			data_width = <3 3 0 0>;
+			data_width = <3 3>;
 		};
 
 		dma@eb000000 {
@@ -133,7 +133,7 @@
 			chan_allocation_order = <1>;
 			chan_priority = <1>;
 			block_size = <0xfff>;
-			data_width = <3 3 0 0>;
+			data_width = <3 3>;
 		};
 
 		fsmc: flash@b0000000 {

arch/avr32/mach-at32ap/at32ap700x.c

@@ -607,7 +607,7 @@ static struct dw_dma_platform_data dw_dmac0_data = {
 	.nr_channels	= 3,
 	.block_size	= 4095U,
 	.nr_masters	= 2,
-	.data_width	= { 2, 2, 0, 0 },
+	.data_width	= { 2, 2 },
 };
 
 static struct resource dw_dmac0_resource[] = {

drivers/dma/dw/core.c

@@ -1562,7 +1562,8 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
 		}
 	} else {
 		dw->nr_masters = pdata->nr_masters;
-		memcpy(dw->data_width, pdata->data_width, 4);
+		for (i = 0; i < dw->nr_masters; i++)
+			dw->data_width[i] = pdata->data_width[i];
 	}
 
 	/* Calculate all channel mask before DMA setup */

drivers/dma/dw/platform.c

@@ -99,7 +99,7 @@ dw_dma_parse_dt(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct dw_dma_platform_data *pdata;
-	u32 tmp, arr[4];
+	u32 tmp, arr[DW_DMA_MAX_NR_MASTERS];
 
 	if (!np) {
 		dev_err(&pdev->dev, "Missing DT data\n");
@@ -126,7 +126,7 @@ dw_dma_parse_dt(struct platform_device *pdev)
 		pdata->block_size = tmp;
 
 	if (!of_property_read_u32(np, "dma-masters", &tmp)) {
-		if (tmp > 4)
+		if (tmp > DW_DMA_MAX_NR_MASTERS)
 			return NULL;
 
 		pdata->nr_masters = tmp;

drivers/dma/dw/regs.h

@@ -285,7 +285,7 @@ struct dw_dma {
 
 	/* hardware configuration */
 	unsigned char		nr_masters;
-	unsigned char		data_width[4];
+	unsigned char		data_width[DW_DMA_MAX_NR_MASTERS];
 };
 
 static inline struct dw_dma_regs __iomem *__dw_regs(struct dw_dma *dw)

include/linux/platform_data/dma-dw.h

@@ -13,6 +13,8 @@
 
 #include <linux/device.h>
 
+#define DW_DMA_MAX_NR_MASTERS	4
+
 /**
  * struct dw_dma_slave - Controller-specific information about a slave
  *
@@ -53,7 +55,7 @@ struct dw_dma_platform_data {
 	unsigned char	chan_priority;
 	unsigned short	block_size;
 	unsigned char	nr_masters;
-	unsigned char	data_width[4];
+	unsigned char	data_width[DW_DMA_MAX_NR_MASTERS];
 };
 
 #endif /* _PLATFORM_DATA_DMA_DW_H */