Add support for of_property_read_u8_index(), simillar to others
u16 and u32 variants. Having this helper makes the code more tidy in
isome cases, specially when we are parsing multiple of these into
data structures.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxxxxxxxx>
Reviewed-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
---
drivers/of/property.c | 33 +++++++++++++++++++++++++++++++++
include/linux/of.h | 9 +++++++++
2 files changed, 42 insertions(+)
diff --git a/drivers/of/property.c b/drivers/of/property.c
index c1feb631e383..4e3524227720 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -147,6 +147,39 @@ static void *of_find_property_value_of_size(const struct device_node *np,
return prop->value;
}
+/**
+ * of_property_read_u8_index - Find and read a u8 from a multi-value 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 u8 in the list of values
+ * @out_value: pointer to return value, modified only if no error.
+ *
+ * Search for a property in a device node and read nth 8-bit value from
+ * it.
+ *
+ * Return: 0 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.
+ *
+ * The out_value is modified only if a valid u8 value can be decoded.
+ */
+int of_property_read_u8_index(const struct device_node *np,
+ const char *propname,
+ u32 index, u8 *out_value)
+{
+ const u8 *val = of_find_property_value_of_size(np, propname,
+ ((index + 1) * sizeof(*out_value)),
+ 0, NULL);
+
+ if (IS_ERR(val))
+ return PTR_ERR(val);
+
+ *out_value = val[index];
+ return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u8_index);
+
/**
* of_property_read_u16_index - Find and read a u16 from a multi-value property.
*
diff --git a/include/linux/of.h b/include/linux/of.h
index a62154aeda1b..0c95e26c7191 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -316,6 +316,9 @@ extern struct property *of_find_property(const struct device_node *np,
extern bool of_property_read_bool(const struct device_node *np, const char *propname);
extern int of_property_count_elems_of_size(const struct device_node *np,
const char *propname, int elem_size);
+extern int of_property_read_u8_index(const struct device_node *np,
+ const char *propname,
+ u32 index, u8 *out_value);
extern int of_property_read_u16_index(const struct device_node *np,
const char *propname,
u32 index, u16 *out_value);
@@ -639,6 +642,12 @@ static inline int of_property_count_elems_of_size(const struct device_node *np,
return -ENOSYS;
}
+static inline int of_property_read_u8_index(const struct device_node *np,
+ const char *propname, u32 index, u8 *out_value)
+{
+ return -ENOSYS;
+}
+
static inline int of_property_read_u16_index(const struct device_node *np,
const char *propname, u32 index, u16 *out_value)
{
--
2.50.0
