iommu: Remove unused of_get_dma_window()

of_get_dma_window() was added in 2012 and removed in 2014 in commit
891846516317 ("memory: Add NVIDIA Tegra memory controller support").
Remove it and simplify the header to use forward declarations for
structs rather than includes.

Cc: Joerg Roedel <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: Frank Rowand <[e-mail]>
Cc: [e-mail]
Signed-off-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Joerg Roedel <[e-mail]>

drivers/iommu/of_iommu.c

···
 
 #define NO_IOMMU	1
 
-/**
- * of_get_dma_window - Parse *dma-window property and returns 0 if found.
- *
- * @dn: device node
- * @prefix: prefix for property name if any
- * @index: index to start to parse
- * @busno: Returns busno if supported. Otherwise pass NULL
- * @addr: Returns address that DMA starts
- * @size: Returns the range that DMA can handle
- *
- * This supports different formats flexibly. "prefix" can be
- * configured if any. "busno" and "index" are optionally
- * specified. Set 0(or NULL) if not used.
- */
-int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
-		      unsigned long *busno, dma_addr_t *addr, size_t *size)
-{
-	const __be32 *dma_window, *end;
-	int bytes, cur_index = 0;
-	char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX];
-
-	if (!dn || !addr || !size)
-		return -EINVAL;
-
-	if (!prefix)
-		prefix = "";
-
-	snprintf(propname, sizeof(propname), "%sdma-window", prefix);
-	snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);
-	snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);
-
-	dma_window = of_get_property(dn, propname, &bytes);
-	if (!dma_window)
-		return -ENODEV;
-	end = dma_window + bytes / sizeof(*dma_window);
-
-	while (dma_window < end) {
-		u32 cells;
-		const void *prop;
-
-		/* busno is one cell if supported */
-		if (busno)
-			*busno = be32_to_cpup(dma_window++);
-
-		prop = of_get_property(dn, addrname, NULL);
-		if (!prop)
-			prop = of_get_property(dn, "#address-cells", NULL);
-
-		cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
-		if (!cells)
-			return -EINVAL;
-		*addr = of_read_number(dma_window, cells);
-		dma_window += cells;
-
-		prop = of_get_property(dn, sizename, NULL);
-		cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn);
-		if (!cells)
-			return -EINVAL;
-		*size = of_read_number(dma_window, cells);
-		dma_window += cells;
-
-		if (cur_index++ == index)
-			break;
-	}
-	return 0;
-}
-EXPORT_SYMBOL_GPL(of_get_dma_window);
-
 static int of_iommu_xlate(struct device *dev,
 			  struct of_phandle_args *iommu_spec)
 {

include/linux/of_iommu.h

···
 #ifndef __OF_IOMMU_H
 #define __OF_IOMMU_H
 
-#include <linux/device.h>
-#include <linux/iommu.h>
-#include <linux/of.h>
+struct device;
+struct device_node;
+struct iommu_ops;
 
 #ifdef CONFIG_OF_IOMMU
-
-extern int of_get_dma_window(struct device_node *dn, const char *prefix,
-			     int index, unsigned long *busno, dma_addr_t *addr,
-			     size_t *size);
 
 extern const struct iommu_ops *of_iommu_configure(struct device *dev,
 					struct device_node *master_np,
 					const u32 *id);
 
 #else
-
-static inline int of_get_dma_window(struct device_node *dn, const char *prefix,
-			    int index, unsigned long *busno, dma_addr_t *addr,
-			    size_t *size)
-{
-	return -EINVAL;
-}
 
 static inline const struct iommu_ops *of_iommu_configure(struct device *dev,
 					 struct device_node *master_np,