drivers/of/base.c: Add of_property_read_u64_index

BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1690412
There is of_property_read_u32_index but no u64 variant. This patch
adds one similar to the u32 version for u64.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from commit 2475a2b6c877a0c8d1ca42c3f2b30f8ce518ac0b)
Signed-off-by: Breno Leitao <breno.leitao@gmail.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/drivers/of/base.c b/drivers/of/base.c
index d4bea3c797d6a7b6a4d28c55cfdff1d30d03cc16..4dac72cf662f7f28fdb2848b1c121b9ce561234c 100644 (file)
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1208,6 +1208,37 @@ int of_property_read_u32_index(const struct device_node *np,
 }
 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
 
+/**
+ * of_property_read_u64_index - Find and read a u64 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 u64 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 64-bit value from
+ * it. Returns 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 u64 value can be decoded.
+ */
+int of_property_read_u64_index(const struct device_node *np,
+                                      const char *propname,
+                                      u32 index, u64 *out_value)
+{
+       const u64 *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 = be64_to_cpup(((__be64 *)val) + index);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64_index);
+
 /**
  * of_property_read_variable_u8_array - Find and read an array of u8 from a
  * property, with bounds on the minimum and maximum array size.

diff --git a/include/linux/of.h b/include/linux/of.h
index d72f01009297342d3c5b45946c84c8e3b7bc51bb..53d5208b874a72106255afd78975d582b1530b9b 100644 (file)
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -291,6 +291,9 @@ extern int of_property_count_elems_of_size(const struct device_node *np,
 extern int of_property_read_u32_index(const struct device_node *np,
                                       const char *propname,
                                       u32 index, u32 *out_value);
+extern int of_property_read_u64_index(const struct device_node *np,
+                                      const char *propname,
+                                      u32 index, u64 *out_value);
 extern int of_property_read_variable_u8_array(const struct device_node *np,
                                        const char *propname, u8 *out_values,
                                        size_t sz_min, size_t sz_max);