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20#include <linux/export.h>
21#include <linux/limits.h>
22#include <linux/of.h>
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38int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
39 unsigned long *busno, dma_addr_t *addr, size_t *size)
40{
41 const __be32 *dma_window, *end;
42 int bytes, cur_index = 0;
43 char propname[NAME_MAX], addrname[NAME_MAX], sizename[NAME_MAX];
44
45 if (!dn || !addr || !size)
46 return -EINVAL;
47
48 if (!prefix)
49 prefix = "";
50
51 snprintf(propname, sizeof(propname), "%sdma-window", prefix);
52 snprintf(addrname, sizeof(addrname), "%s#dma-address-cells", prefix);
53 snprintf(sizename, sizeof(sizename), "%s#dma-size-cells", prefix);
54
55 dma_window = of_get_property(dn, propname, &bytes);
56 if (!dma_window)
57 return -ENODEV;
58 end = dma_window + bytes / sizeof(*dma_window);
59
60 while (dma_window < end) {
61 u32 cells;
62 const void *prop;
63
64
65 if (busno)
66 *busno = be32_to_cpup(dma_window++);
67
68 prop = of_get_property(dn, addrname, NULL);
69 if (!prop)
70 prop = of_get_property(dn, "#address-cells", NULL);
71
72 cells = prop ? be32_to_cpup(prop) : of_n_addr_cells(dn);
73 if (!cells)
74 return -EINVAL;
75 *addr = of_read_number(dma_window, cells);
76 dma_window += cells;
77
78 prop = of_get_property(dn, sizename, NULL);
79 cells = prop ? be32_to_cpup(prop) : of_n_size_cells(dn);
80 if (!cells)
81 return -EINVAL;
82 *size = of_read_number(dma_window, cells);
83 dma_window += cells;
84
85 if (cur_index++ == index)
86 break;
87 }
88 return 0;
89}
90EXPORT_SYMBOL_GPL(of_get_dma_window);
91