diff options
Diffstat (limited to 'drivers/of/base.c')
| -rw-r--r-- | drivers/of/base.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 8d173fb3552a..ae03b1218b06 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -416,6 +416,42 @@ int of_cpu_node_to_id(struct device_node *cpu_node) EXPORT_SYMBOL(of_cpu_node_to_id); /** + * of_get_cpu_state_node - Get CPU's idle state node at the given index + * + * @cpu_node: The device node for the CPU + * @index: The index in the list of the idle states + * + * Two generic methods can be used to describe a CPU's idle states, either via + * a flattened description through the "cpu-idle-states" binding or via the + * hierarchical layout, using the "power-domains" and the "domain-idle-states" + * bindings. This function check for both and returns the idle state node for + * the requested index. + * + * In case an idle state node is found at @index, the refcount is incremented + * for it, so call of_node_put() on it when done. Returns NULL if not found. + */ +struct device_node *of_get_cpu_state_node(struct device_node *cpu_node, + int index) +{ + struct of_phandle_args args; + int err; + + err = of_parse_phandle_with_args(cpu_node, "power-domains", + "#power-domain-cells", 0, &args); + if (!err) { + struct device_node *state_node = + of_parse_phandle(args.np, "domain-idle-states", index); + + of_node_put(args.np); + if (state_node) + return state_node; + } + + return of_parse_phandle(cpu_node, "cpu-idle-states", index); +} +EXPORT_SYMBOL(of_get_cpu_state_node); + +/** * __of_device_is_compatible() - Check if the node matches given constraints * @device: pointer to node * @compat: required compatible string, NULL or "" for any match |