of: Make of_find_property_value_of_size take a length range

In preparation for adding variable-length array reads, change
of_find_property_value_of_size so that it takes an optional
maximum length. If the maximum is passed as 0, the behaviour is
unchanged and it will return a property if it's >= the requested
minimum length. If maximum is non-zero it will only return a
property whose length is min <= l <= max.

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Rob Herring <robh@kernel.org>

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 3ce69536a7b3c3832f652ff7b2c43bd9f0db506e..b85373768ce108050c7cf2b4886eb9f9ec962458 100644 (file)
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1146,16 +1146,18 @@ EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
  *
  * @np:                device node from which the property value is to be read.
  * @propname:  name of the property to be searched.
- * @len:       requested length of property value
+ * @min:       minimum allowed length of property value
+ * @max:       maximum allowed length of property value (0 means unlimited)
+ * @len:       if !=NULL, actual length is written to here
  *
  * Search for a property in a device node and valid the requested size.
  * Returns the property value on success, -EINVAL if the property does not
  *  exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
- * property data isn't large enough.
+ * property data is too small or too large.
  *
  */
 static void *of_find_property_value_of_size(const struct device_node *np,
-                       const char *propname, u32 len)
+                       const char *propname, u32 min, u32 max, size_t *len)
 {
        struct property *prop = of_find_property(np, propname, NULL);
 
@@ -1163,9 +1165,14 @@ static void *of_find_property_value_of_size(const struct device_node *np,
                return ERR_PTR(-EINVAL);
        if (!prop->value)
                return ERR_PTR(-ENODATA);
-       if (len > prop->length)
+       if (prop->length < min)
+               return ERR_PTR(-EOVERFLOW);
+       if (max && prop->length > max)
                return ERR_PTR(-EOVERFLOW);
 
+       if (len)
+               *len = prop->length;
+
        return prop->value;
 }
 
@@ -1189,7 +1196,9 @@ int of_property_read_u32_index(const struct device_node *np,
                                       u32 index, u32 *out_value)
 {
        const u32 *val = of_find_property_value_of_size(np, propname,
-                                       ((index + 1) * sizeof(*out_value)));
+                                       ((index + 1) * sizeof(*out_value)),
+                                       0,
+                                       NULL);
 
        if (IS_ERR(val))
                return PTR_ERR(val);
@@ -1221,7 +1230,9 @@ int of_property_read_u8_array(const struct device_node *np,
                        const char *propname, u8 *out_values, size_t sz)
 {
        const u8 *val = of_find_property_value_of_size(np, propname,
-                                               (sz * sizeof(*out_values)));
+                                               (sz * sizeof(*out_values)),
+                                               0,
+                                               NULL);
 
        if (IS_ERR(val))
                return PTR_ERR(val);
@@ -1254,7 +1265,9 @@ int of_property_read_u16_array(const struct device_node *np,
                        const char *propname, u16 *out_values, size_t sz)
 {
        const __be16 *val = of_find_property_value_of_size(np, propname,
-                                               (sz * sizeof(*out_values)));
+                                               (sz * sizeof(*out_values)),
+                                               0,
+                                               NULL);
 
        if (IS_ERR(val))
                return PTR_ERR(val);
@@ -1286,7 +1299,9 @@ int of_property_read_u32_array(const struct device_node *np,
                               size_t sz)
 {
        const __be32 *val = of_find_property_value_of_size(np, propname,
-                                               (sz * sizeof(*out_values)));
+                                               (sz * sizeof(*out_values)),
+                                               0,
+                                               NULL);
 
        if (IS_ERR(val))
                return PTR_ERR(val);
@@ -1314,7 +1329,9 @@ int of_property_read_u64(const struct device_node *np, const char *propname,
                         u64 *out_value)
 {
        const __be32 *val = of_find_property_value_of_size(np, propname,
-                                               sizeof(*out_value));
+                                               sizeof(*out_value),
+                                               0,
+                                               NULL);
 
        if (IS_ERR(val))
                return PTR_ERR(val);
@@ -1345,7 +1362,9 @@ int of_property_read_u64_array(const struct device_node *np,
                               size_t sz)
 {
        const __be32 *val = of_find_property_value_of_size(np, propname,
-                                               (sz * sizeof(*out_values)));
+                                               (sz * sizeof(*out_values)),
+                                               0,
+                                               NULL);
 
        if (IS_ERR(val))
                return PTR_ERR(val);