libfdt: Add max phandle retrieval function

Add a function to retrieve the highest phandle in a given device tree.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Acked-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Maxime Ripard 2016-07-05 10:26:39 +02:00 committed by Tom Rini
parent 67e610d9f0
commit 57c7809ab0
2 changed files with 39 additions and 0 deletions

View File

@ -283,6 +283,19 @@ int fdt_move(const void *fdt, void *buf, int bufsize);
*/
const char *fdt_string(const void *fdt, int stroffset);
/**
* fdt_get_max_phandle - retrieves the highest phandle in a tree
* @fdt: pointer to the device tree blob
*
* fdt_get_max_phandle retrieves the highest phandle in the given
* device tree
*
* returns:
* the highest phandle on success
* 0, if an error occurred
*/
uint32_t fdt_get_max_phandle(const void *fdt);
/**
* fdt_num_mem_rsv - retrieve the number of memory reserve map entries
* @fdt: pointer to the device tree blob

View File

@ -47,6 +47,32 @@ static int _fdt_string_eq(const void *fdt, int stroffset,
return (strnlen(p, len + 1) == len) && (memcmp(p, s, len) == 0);
}
uint32_t fdt_get_max_phandle(const void *fdt)
{
uint32_t max_phandle = 0;
int offset;
for (offset = fdt_next_node(fdt, -1, NULL);;
offset = fdt_next_node(fdt, offset, NULL)) {
uint32_t phandle;
if (offset == -FDT_ERR_NOTFOUND)
return max_phandle;
if (offset < 0)
return 0;
phandle = fdt_get_phandle(fdt, offset);
if (phandle == (uint32_t)-1)
return 0;
if (phandle > max_phandle)
max_phandle = phandle;
}
return 0;
}
int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
{
FDT_CHECK_HEADER(fdt);