fdt: Add a function to count strings

Given a device tree node and a property name, the fdt_stringlist_count()
function counts the number of strings found in the property value.

This also adds a new error code, FDT_ERR_BADVALUE, that the function
returns when it encounters a non-NUL-terminated string list.

Signed-off-by: Thierry Reding <treding@nvidia.com>
[Changed testcase name --dwg]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Thierry Reding 2015-09-30 13:16:12 +10:00 committed by David Gibson
parent 554fde2c77
commit 2218387a8c
7 changed files with 142 additions and 1 deletions

View file

@ -538,6 +538,31 @@ int fdt_stringlist_contains(const char *strlist, int listlen, const char *str)
return 0;
}
int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property)
{
const char *list, *end;
int length, count = 0;
list = fdt_getprop(fdt, nodeoffset, property, &length);
if (!list)
return -length;
end = list + length;
while (list < end) {
length = strnlen(list, end - list) + 1;
/* Abort if the last string isn't properly NUL-terminated. */
if (list + length > end)
return -FDT_ERR_BADVALUE;
list += length;
count++;
}
return count;
}
int fdt_node_check_compatible(const void *fdt, int nodeoffset,
const char *compatible)
{

View file

@ -121,7 +121,12 @@
/* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
* or similar property with a bad format or value */
#define FDT_ERR_MAX 14
#define FDT_ERR_BADVALUE 15
/* FDT_ERR_BADVALUE: Device tree has a property with an unexpected
* value. For example: a property expected to contain a string list
* is not NUL-terminated within the length of its value. */
#define FDT_ERR_MAX 15
/**********************************************************************/
/* Low-level functions (you probably don't need these) */
@ -868,6 +873,18 @@ int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
*/
int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
/**
* fdt_stringlist_count - count the number of strings in a string list
* @fdt: pointer to the device tree blob
* @nodeoffset: offset of a tree node
* @property: name of the property containing the string list
* @return:
* the number of strings in the given property
* -FDT_ERR_BADVALUE if the property value is not NUL-terminated
* -FDT_ERR_NOTFOUND if the property does not exist
*/
int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property);
/**********************************************************************/
/* Read-only functions (addressing related) */
/**********************************************************************/