Merge branch 'for-3.2-rc' of git://gitorious.org/linux-omap-dss2/linux into fbdev...

[pandora-kernel.git] / drivers / of / base.c

diff --git a/drivers/of/base.c b/drivers/of/base.c
index b970562..9b6588e 100644 (file)
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -715,6 +715,90 @@ int of_property_read_string(struct device_node *np, const char *propname,
 }
 EXPORT_SYMBOL_GPL(of_property_read_string);
 
+/**
+ * of_property_read_string_index - Find and read a string from a multiple
+ * strings property.
+ * @np:                device node from which the property value is to be read.
+ * @propname:  name of the property to be searched.
+ * @index:     index of the string in the list of strings
+ * @out_string:        pointer to null terminated return string, modified only if
+ *             return value is 0.
+ *
+ * Search for a property in a device tree node and retrieve a null
+ * terminated string value (pointer to data, not a copy) in the list of strings
+ * contained in that property.
+ * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
+ * property does not have a value, and -EILSEQ if the string is not
+ * null-terminated within the length of the property data.
+ *
+ * The out_string pointer is modified only if a valid string can be decoded.
+ */
+int of_property_read_string_index(struct device_node *np, const char *propname,
+                                 int index, const char **output)
+{
+       struct property *prop = of_find_property(np, propname, NULL);
+       int i = 0;
+       size_t l = 0, total = 0;
+       const char *p;
+
+       if (!prop)
+               return -EINVAL;
+       if (!prop->value)
+               return -ENODATA;
+       if (strnlen(prop->value, prop->length) >= prop->length)
+               return -EILSEQ;
+
+       p = prop->value;
+
+       for (i = 0; total < prop->length; total += l, p += l) {
+               l = strlen(p) + 1;
+               if ((*p != 0) && (i++ == index)) {
+                       *output = p;
+                       return 0;
+               }
+       }
+       return -ENODATA;
+}
+EXPORT_SYMBOL_GPL(of_property_read_string_index);
+
+
+/**
+ * of_property_count_strings - Find and return the number of strings from a
+ * multiple strings property.
+ * @np:                device node from which the property value is to be read.
+ * @propname:  name of the property to be searched.
+ *
+ * Search for a property in a device tree node and retrieve the number of null
+ * terminated string contain in it. Returns the number of strings on
+ * success, -EINVAL if the property does not exist, -ENODATA if property
+ * does not have a value, and -EILSEQ if the string is not null-terminated
+ * within the length of the property data.
+ */
+int of_property_count_strings(struct device_node *np, const char *propname)
+{
+       struct property *prop = of_find_property(np, propname, NULL);
+       int i = 0;
+       size_t l = 0, total = 0;
+       const char *p;
+
+       if (!prop)
+               return -EINVAL;
+       if (!prop->value)
+               return -ENODATA;
+       if (strnlen(prop->value, prop->length) >= prop->length)
+               return -EILSEQ;
+
+       p = prop->value;
+
+       for (i = 0; total < prop->length; total += l, p += l) {
+               l = strlen(p) + 1;
+               if (*p != 0)
+                       i++;
+       }
+       return i;
+}
+EXPORT_SYMBOL_GPL(of_property_count_strings);
+
 /**
  * of_parse_phandle - Resolve a phandle property to a device_node pointer
  * @np: Pointer to device node holding phandle property