lib: utils/fdt: Add fdt_parse_phandle_with_args() API

The libfdt project does not have a generic API to parse phandle
with args from a DT node so we add fdt_parse_phandle_with_args()
for this purpose. This new API will be useful to FDT based drivers.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
This commit is contained in:
Anup Patel 2021-07-13 11:23:41 +08:00 committed by Anup Patel
parent 17729d44da
commit e931f387b2
2 changed files with 58 additions and 0 deletions

View File

@ -17,6 +17,13 @@ struct fdt_match {
void *data;
};
#define FDT_MAX_PHANDLE_ARGS 16
struct fdt_phandle_args {
int node_offset;
int args_count;
u32 args[FDT_MAX_PHANDLE_ARGS];
};
struct platform_uart_data {
unsigned long addr;
unsigned long freq;
@ -32,6 +39,10 @@ int fdt_find_match(void *fdt, int startoff,
const struct fdt_match *match_table,
const struct fdt_match **out_match);
int fdt_parse_phandle_with_args(void *fdt, int nodeoff,
const char *prop, const char *cells_prop,
int index, struct fdt_phandle_args *out_args);
int fdt_get_node_addr_size(void *fdt, int node, unsigned long *addr,
unsigned long *size);

View File

@ -72,6 +72,53 @@ int fdt_find_match(void *fdt, int startoff,
return SBI_ENODEV;
}
int fdt_parse_phandle_with_args(void *fdt, int nodeoff,
const char *prop, const char *cells_prop,
int index, struct fdt_phandle_args *out_args)
{
u32 i, pcells;
int len, pnodeoff;
const fdt32_t *list, *list_end, *val;
if (!fdt || (nodeoff < 0) || !prop || !cells_prop || !out_args)
return SBI_EINVAL;
list = fdt_getprop(fdt, nodeoff, prop, &len);
if (!list)
return SBI_ENOENT;
list_end = list + (len / sizeof(*list));
while (list < list_end) {
pnodeoff = fdt_node_offset_by_phandle(fdt,
fdt32_to_cpu(*list));
if (pnodeoff < 0)
return pnodeoff;
list++;
val = fdt_getprop(fdt, pnodeoff, cells_prop, &len);
if (!val)
return SBI_ENOENT;
pcells = fdt32_to_cpu(*val);
if (FDT_MAX_PHANDLE_ARGS < pcells)
return SBI_EINVAL;
if (list + pcells > list_end)
return SBI_ENOENT;
if (index > 0) {
list += pcells;
index--;
} else {
out_args->node_offset = pnodeoff;
out_args->args_count = pcells;
for (i = 0; i < pcells; i++)
out_args->args[i] = fdt32_to_cpu(list[i]);
return 0;
}
}
return SBI_ENOENT;
}
static int fdt_translate_address(void *fdt, uint64_t reg, int parent,
unsigned long *addr)
{