fdt: Add functions to access phandles, arrays and bools

Add a function to look up a property which is a phandle in a node, and
another to read a fixed-length integer array from an fdt property.
Also add a function to read boolean properties, although there is no
actual boolean type in U-Boot.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Gerald Van Baren <vanbaren@cideas.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
This commit is contained in:
Simon Glass 2012-02-27 10:52:35 +00:00 committed by Albert ARIBAUD
parent f88fe2ded4
commit d17da65560
2 changed files with 106 additions and 0 deletions

View File

@ -188,3 +188,42 @@ int fdtdec_find_aliases_for_id(const void *blob, const char *name,
* @return compatible string for that id
*/
const char *fdtdec_get_compatible(enum fdt_compat_id id);
/* Look up a phandle and follow it to its node. Then return the offset
* of that node.
*
* @param blob FDT blob
* @param node node to examine
* @param prop_name name of property to find
* @return node offset if found, -ve error code on error
*/
int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
/**
* Look up a property in a node and return its contents in an integer
* array of given length. The property must have at least enough data for
* the array (4*count bytes). It may have more, but this will be ignored.
*
* @param blob FDT blob
* @param node node to examine
* @param prop_name name of property to find
* @param array array to fill with data
* @param count number of array elements
* @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
* or -FDT_ERR_BADLAYOUT if not enough data
*/
int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
u32 *array, int count);
/**
* Look up a boolean property in a node and return it.
*
* A boolean properly is true if present in the device tree and false if not
* present, regardless of its value.
*
* @param blob FDT blob
* @param node node to examine
* @param prop_name name of property to find
* @return 1 if the properly is present; 0 if it isn't present
*/
int fdtdec_get_bool(const void *blob, int node, const char *prop_name);

View File

@ -271,3 +271,70 @@ int fdtdec_check_fdt(void)
"binary or define CONFIG_OF_EMBED\n");
return 0;
}
int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
{
const u32 *phandle;
int lookup;
phandle = fdt_getprop(blob, node, prop_name, NULL);
if (!phandle)
return -FDT_ERR_NOTFOUND;
lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
return lookup;
}
/**
* Look up a property in a node and check that it has a minimum length.
*
* @param blob FDT blob
* @param node node to examine
* @param prop_name name of property to find
* @param min_len minimum property length in bytes
* @param err 0 if ok, or -FDT_ERR_NOTFOUND if the property is not
found, or -FDT_ERR_BADLAYOUT if not enough data
* @return pointer to cell, which is only valid if err == 0
*/
static const void *get_prop_check_min_len(const void *blob, int node,
const char *prop_name, int min_len, int *err)
{
const void *cell;
int len;
debug("%s: %s\n", __func__, prop_name);
cell = fdt_getprop(blob, node, prop_name, &len);
if (!cell)
*err = -FDT_ERR_NOTFOUND;
else if (len < min_len)
*err = -FDT_ERR_BADLAYOUT;
else
*err = 0;
return cell;
}
int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
u32 *array, int count)
{
const u32 *cell;
int i, err = 0;
debug("%s: %s\n", __func__, prop_name);
cell = get_prop_check_min_len(blob, node, prop_name,
sizeof(u32) * count, &err);
if (!err) {
for (i = 0; i < count; i++)
array[i] = fdt32_to_cpu(cell[i]);
}
return err;
}
int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
{
const s32 *cell;
int len;
debug("%s: %s\n", __func__, prop_name);
cell = fdt_getprop(blob, node, prop_name, &len);
return cell != NULL;
}