openthread: Move OpenThread implementation from net to modules

Move OpenThread-related code from
zephyr/subsys/net/l2/openthread/openthread.c to
zephyr/modules/openthread/openthread_module.c.

The primary goal of this refactor is to enable the use
of OpenThread as an independent module, without the necessity
of Zephyr's networking layer.

This change is particularly beneficial for simple applications
that have their own implementation of the IEEE802.15.4 driver
and do not require a networking layer. These applications can
now disable Zephyr's L2 and IEEE802.15.4 shim layers and
directly use the OpenThread module, saving valuable kilobytes
of memory.

In this approach if the CONFIG_NET_L2_OPENTHREAD
Kconfig option is set, Zephyr's L2 and IEEE802.15.4 layer
will be used, and everything will function as before.
The main difference is the Zephyr's L2 layer now uses
the OpenThread module, no longer implementing it.

If the CONFIG_NET_L2_OPENTHREAD Kconfig option is
not set, the opentherad_init function will be called at
system boot in the POST_KERNEL phase.

While most of the functions in include/net/openthread.h
have been deprecated, they are still available for use to
maintain backwards compatibility.
These functions now act as an interface to the new ones
defined in modules/openthread.

Signed-off-by: Arkadiusz Balys <[email protected]>

Author: ArekBalysNordic

include/zephyr/net/openthread.h

@@ -44,9 +44,6 @@ struct pkt_list_elem {
  * @brief OpenThread l2 private data.
  */
 struct openthread_context {
-	/** Pointer to OpenThread stack instance */
-	otInstance *instance;
-
 	/** Pointer to OpenThread network interface */
 	struct net_if *iface;
 
@@ -62,23 +59,10 @@ struct openthread_context {
 	/** Array for storing net_pkt for OpenThread internal usage */
 	struct pkt_list_elem pkt_list[CONFIG_OPENTHREAD_PKT_LIST_SIZE];
 
-	/** A mutex to protect API calls from being preempted. */
-	struct k_mutex api_lock;
-
-	/** A work queue for all OpenThread activity */
-	struct k_work_q work_q;
-
-	/** Work object for OpenThread internal usage */
-	struct k_work api_work;
-
-	/** A list for state change callbacks */
-	sys_slist_t state_change_cbs;
+	/** @deprecated A list for state change callbacks */
+	sys_slist_t ot_state_change_cbs;
 };
-/**
- * INTERNAL_HIDDEN @endcond
- */
 
-/** OpenThread state change callback  */
 
 /**
  * @brief OpenThread state change callback structure
@@ -111,29 +95,34 @@ struct openthread_state_changed_cb {
 };
 
 /**
+ * INTERNAL_HIDDEN @endcond
+ */
+
+/** OpenThread state change callback  */
+
+/**
+ * @deprecated use @ref openthread_state_changed_callback_register from modules/openthread instead.
+ *
  * @brief Registers callbacks which will be called when certain configuration
  * or state changes occur within OpenThread.
  *
  * @param ot_context the OpenThread context to register the callback with.
  * @param cb callback struct to register.
  */
-int openthread_state_changed_cb_register(struct openthread_context *ot_context,
+__deprecated int openthread_state_changed_cb_register(struct openthread_context *ot_context,
 					 struct openthread_state_changed_cb *cb);
 
 /**
+ * @deprecated use @ref openthread_state_changed_callback_unregister from modules/openthread instead.
+ *
  * @brief Unregisters OpenThread configuration or state changed callbacks.
  *
  * @param ot_context the OpenThread context to unregister the callback from.
  * @param cb callback struct to unregister.
  */
-int openthread_state_changed_cb_unregister(struct openthread_context *ot_context,
+__deprecated int openthread_state_changed_cb_unregister(struct openthread_context *ot_context,
 					   struct openthread_state_changed_cb *cb);
 
-/**
- * @brief Get OpenThread thread identification.
- */
-k_tid_t openthread_thread_id_get(void);
-
 /**
  * @brief Get pointer to default OpenThread context.
  *
@@ -143,25 +132,8 @@ k_tid_t openthread_thread_id_get(void);
 struct openthread_context *openthread_get_default_context(void);
 
 /**
- * @brief Get pointer to default OpenThread instance.
+ * @deprecated use @ref openthread_mutex_lock from modules/openthread instead.
  *
- * @retval !NULL On success.
- * @retval NULL  On failure.
- */
-struct otInstance *openthread_get_default_instance(void);
-
-/**
- * @brief Starts the OpenThread network.
- *
- * @details Depends on active settings: it uses stored network configuration,
- * start joining procedure or uses default network configuration. Additionally
- * when the device is MTD, it sets the SED mode to properly attach the network.
- *
- * @param ot_context
- */
-int openthread_start(struct openthread_context *ot_context);
-
-/**
  * @brief Lock internal mutex before accessing OT API.
  *
  * @details OpenThread API is not thread-safe, therefore before accessing any
@@ -170,9 +142,11 @@ int openthread_start(struct openthread_context *ot_context);
  *
  * @param ot_context Context to lock.
  */
-void openthread_api_mutex_lock(struct openthread_context *ot_context);
+__deprecated void openthread_api_mutex_lock(struct openthread_context *ot_context);
 
 /**
+ * @deprecated use @ref openthread_mutex_try_lock from modules/openthread instead.
+ *
  * @brief Try to lock internal mutex before accessing OT API.
  *
  * @details This function behaves like openthread_api_mutex_lock() provided that
@@ -183,14 +157,16 @@ void openthread_api_mutex_lock(struct openthread_context *ot_context);
  * @retval 0  On success.
  * @retval <0 On failure.
  */
-int openthread_api_mutex_try_lock(struct openthread_context *ot_context);
+__deprecated int openthread_api_mutex_try_lock(struct openthread_context *ot_context);
 
 /**
+ * @deprecated use @ref openthread_mutex_unlock from modules/openthread instead.
+ *
  * @brief Unlock internal mutex after accessing OT API.
  *
  * @param ot_context Context to unlock.
  */
-void openthread_api_mutex_unlock(struct openthread_context *ot_context);
+__deprecated void openthread_api_mutex_unlock(struct openthread_context *ot_context);
 
 /** @cond INTERNAL_HIDDEN */
 

modules/openthread/Kconfig

@@ -8,6 +8,14 @@ config OPENTHREAD
 
 if OPENTHREAD
 
+config OPENTHREAD_AUTO_INITIALIZE
+	bool "Automatically initialize OpenThread"
+	default y
+	depends on !NET_L2_OPENTHREAD
+	help
+	  This option automatically initializes OpenThread when the the
+	  Zephyr's networking layer is not enabled.
+
 menu "OpenThread stack features"
 rsource "Kconfig.features"
 endmenu