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/* SPDX-License-Identifier: MIT */
#include "devicetree.h"
#include "libfdt/libfdt.h"
void dt_parse_ranges(void *dt, int node, struct dt_ranges_tbl *ranges)
{
int len;
const struct fdt_property *ranges_prop = fdt_get_property(dt, node, "ranges", &len);
if (ranges_prop && len > 0) {
int idx = 0;
int num_entries = len / sizeof(fdt64_t);
if (num_entries > DT_MAX_RANGES)
num_entries = DT_MAX_RANGES;
const fdt64_t *entry = (const fdt64_t *)ranges_prop->data;
for (int i = 0; i < num_entries; ++i) {
u64 start = fdt64_ld(entry++);
u64 parent = fdt64_ld(entry++);
u64 size = fdt64_ld(entry++);
if (size) {
ranges[idx].start = start;
ranges[idx].parent = parent;
ranges[idx].size = size;
idx++;
}
}
}
}
u64 dt_translate(struct dt_ranges_tbl *ranges, const fdt64_t *reg)
{
u64 addr = fdt64_ld(reg);
for (int idx = 0; idx < DT_MAX_RANGES; ++idx) {
if (ranges[idx].size == 0)
break;
if (addr >= ranges[idx].start && addr < ranges[idx].start + ranges[idx].size)
return ranges[idx].parent - ranges[idx].start + addr;
}
return addr;
}
u64 dt_get_address(void *dt, int node)
{
int parent = fdt_parent_offset(dt, node);
// find parent with "ranges" property
while (parent >= 0) {
if (fdt_getprop(dt, parent, "ranges", NULL))
break;
parent = fdt_parent_offset(dt, parent);
}
if (parent < 0)
return 0;
// parse ranges for address translation
struct dt_ranges_tbl ranges[DT_MAX_RANGES] = {0};
dt_parse_ranges(dt, parent, ranges);
const fdt64_t *reg = fdt_getprop(dt, node, "reg", NULL);
if (!reg)
return 0;
return dt_translate(ranges, reg);
}
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