For device nodes in both DT and ACPI, it possible to have named child nodes which contain properties (an existing example being gpio-leds). This adds a function to find a named child node for a device which can be used by drivers for property retrieval.
For DT data node name matching, of_node_cmp() and similar functions are made available outside of CONFIG_OF block so the new function can reference these for DT and non-DT builds.
For ACPI data node name matching, a helper function is also added which returns false if CONFIG_ACPI is not set, otherwise it performs a string comparison on the data node name. This avoids using the acpi_data_node struct for non CONFIG_ACPI builds, which would otherwise cause a build failure.
Signed-off-by: Adam Thomson Adam.Thomson.Opensource@diasemi.com Tested-by: Sathyanarayana Nujella sathyanarayana.nujella@intel.com Acked-by: Rob Herring robh@kernel.org ---
Changes in v3: - Move of_*_cmp() functions in of.h outside of CONFIG_OF block so they are available for non-DT builds - In device_get_named_child_node(), use of_node_cmp() helper macro instead of strcasecmp() (node names not alway case insensitive, depending on platform).
Changes in v2: - Rebase to v4.7-rc1
drivers/base/property.c | 28 ++++++++++++++++++++++++++++ include/acpi/acpi_bus.h | 7 +++++++ include/linux/acpi.h | 6 ++++++ include/linux/of.h | 14 +++++++------- include/linux/property.h | 3 +++ 5 files changed, 51 insertions(+), 7 deletions(-)
diff --git a/drivers/base/property.c b/drivers/base/property.c index f38c21d..43a36d6 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -888,6 +888,34 @@ struct fwnode_handle *device_get_next_child_node(struct device *dev, EXPORT_SYMBOL_GPL(device_get_next_child_node);
/** + * device_get_named_child_node - Return first matching named child node handle + * @dev: Device to find the named child node for. + * @childname: String to match child node name against. + */ +struct fwnode_handle *device_get_named_child_node(struct device *dev, + const char *childname) +{ + struct fwnode_handle *child; + + /* + * Find first matching named child node of this device. + * For ACPI this will be a data only sub-node. + */ + device_for_each_child_node(dev, child) { + if (is_of_node(child)) { + if (!of_node_cmp(to_of_node(child)->name, childname)) + return child; + } else if (is_acpi_data_node(child)) { + if (acpi_data_node_match(child, childname)) + return child; + } + } + + return NULL; +} +EXPORT_SYMBOL_GPL(device_get_named_child_node); + +/** * fwnode_handle_put - Drop reference to a device node * @fwnode: Pointer to the device node to drop the reference to. * diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 788c6c3..993bdd0 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -420,6 +420,13 @@ static inline struct acpi_data_node *to_acpi_data_node(struct fwnode_handle *fwn container_of(fwnode, struct acpi_data_node, fwnode) : NULL; }
+static inline bool acpi_data_node_match(struct fwnode_handle *fwnode, + const char *name) +{ + return is_acpi_data_node(fwnode) ? + (!strcasecmp(to_acpi_data_node(fwnode)->name, name)) : false; +} + static inline struct fwnode_handle *acpi_fwnode_handle(struct acpi_device *adev) { return &adev->fwnode; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 288fac5..03039c4 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -568,6 +568,12 @@ static inline struct acpi_data_node *to_acpi_data_node(struct fwnode_handle *fwn return NULL; }
+static inline bool acpi_data_node_match(struct fwnode_handle *fwnode, + const char *name) +{ + return false; +} + static inline struct fwnode_handle *acpi_fwnode_handle(struct acpi_device *adev) { return NULL; diff --git a/include/linux/of.h b/include/linux/of.h index 74eb28c..310e32f 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -238,13 +238,6 @@ static inline unsigned long of_read_ulong(const __be32 *cell, int size) #define OF_ROOT_NODE_SIZE_CELLS_DEFAULT 1 #endif
-/* Default string compare functions, Allow arch asm/prom.h to override */ -#if !defined(of_compat_cmp) -#define of_compat_cmp(s1, s2, l) strcasecmp((s1), (s2)) -#define of_prop_cmp(s1, s2) strcmp((s1), (s2)) -#define of_node_cmp(s1, s2) strcasecmp((s1), (s2)) -#endif - #define OF_IS_DYNAMIC(x) test_bit(OF_DYNAMIC, &x->_flags) #define OF_MARK_DYNAMIC(x) set_bit(OF_DYNAMIC, &x->_flags)
@@ -726,6 +719,13 @@ static inline void of_property_clear_flag(struct property *p, unsigned long flag #define of_match_node(_matches, _node) NULL #endif /* CONFIG_OF */
+/* Default string compare functions, Allow arch asm/prom.h to override */ +#if !defined(of_compat_cmp) +#define of_compat_cmp(s1, s2, l) strcasecmp((s1), (s2)) +#define of_prop_cmp(s1, s2) strcmp((s1), (s2)) +#define of_node_cmp(s1, s2) strcasecmp((s1), (s2)) +#endif + #if defined(CONFIG_OF) && defined(CONFIG_NUMA) extern int of_node_to_nid(struct device_node *np); #else diff --git a/include/linux/property.h b/include/linux/property.h index ecab11e..3a2f9ae 100644 --- a/include/linux/property.h +++ b/include/linux/property.h @@ -77,6 +77,9 @@ struct fwnode_handle *device_get_next_child_node(struct device *dev, for (child = device_get_next_child_node(dev, NULL); child; \ child = device_get_next_child_node(dev, child))
+struct fwnode_handle *device_get_named_child_node(struct device *dev, + const char *childname); + void fwnode_handle_put(struct fwnode_handle *fwnode);
unsigned int device_get_child_node_count(struct device *dev); -- 1.9.3