doc: fix usage of :c:type

Fixing issues with recent versions of breathe 4.19.2:

 WARNING: Unparseable C cross-reference: 'struct device'
 Invalid C declaration: Expected identifier in nested name, got keyword:
 struct [error at 6]
   struct device
     ------^

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

doc/reference/kernel/data_passing/fifos.rst

@@ -62,7 +62,7 @@ Implementation
 Defining a FIFO
 ===============
 
-A FIFO is defined using a variable of type :c:type:`struct k_fifo`.
+A FIFO is defined using a variable of type :c:type:`k_fifo`.
 It must then be initialized by calling :cpp:func:`k_fifo_init()`.
 
 The following code defines and initializes an empty FIFO.

doc/reference/kernel/data_passing/lifos.rst

@@ -53,7 +53,7 @@ Implementation
 Defining a LIFO
 ===============
 
-A LIFO is defined using a variable of type :c:type:`struct k_lifo`.
+A LIFO is defined using a variable of type :c:type:`k_lifo`.
 It must then be initialized by calling :cpp:func:`k_lifo_init()`.
 
 The following defines and initializes an empty LIFO.

doc/reference/kernel/data_passing/mailboxes.rst

@@ -118,7 +118,7 @@ Implementation
 Defining a Mailbox
 ==================
 
-A mailbox is defined using a variable of type :c:type:`struct k_mbox`.
+A mailbox is defined using a variable of type :c:type:`k_mbox`.
 It must then be initialized by calling :cpp:func:`k_mbox_init()`.
 
 The following code defines and initializes an empty mailbox.
@@ -141,7 +141,7 @@ The following code has the same effect as the code segment above.
 Message Descriptors
 ===================
 
-A message descriptor is a structure of type :c:type:`struct k_mbox_msg`.
+A message descriptor is a structure of type :c:type:`k_mbox_msg`.
 Only the fields listed below should be used; any other fields are for
 internal mailbox use only.
 

doc/reference/kernel/data_passing/message_queues.rst

@@ -70,7 +70,7 @@ Implementation
 Defining a Message Queue
 ========================
 
-A message queue is defined using a variable of type :c:type:`struct k_msgq`.
+A message queue is defined using a variable of type :c:type:`k_msgq`.
 It must then be initialized by calling :cpp:func:`k_msgq_init()`.
 
 The following code defines and initializes an empty message queue

doc/reference/kernel/data_passing/pipes.rst

@@ -52,8 +52,8 @@ waiting sender(s).
 Implementation
 **************
 
-A pipe is defined using a variable of type :c:type:`struct k_pipe` and an
-optional character buffer of type :c:type:`unsigned char`. It must then be
+A pipe is defined using a variable of type :c:type:`k_pipe` and an
+optional character buffer of type ``unsigned char``. It must then be
 initialized by calling :cpp:func:`k_pipe_init()`.
 
 The following code defines and initializes an empty pipe that has a ring

doc/reference/kernel/data_passing/stacks.rst

@@ -55,7 +55,7 @@ Implementation
 Defining a Stack
 ================
 
-A stack is defined using a variable of type :c:type:`struct k_stack`.
+A stack is defined using a variable of type :c:type:`k_stack`.
 It must then be initialized by calling :cpp:func:`k_stack_init()` or
 :cpp:func:`k_stack_alloc_init()`. In the latter case, a buffer is not
 provided and it is instead allocated from the calling thread's resource

doc/reference/kernel/memory/heap.rst

@@ -13,8 +13,8 @@ Creating a Heap
 ===============
 
 The simplest way to define a heap is statically, with the
-:c:macro:`K_HEAP_DEFINE` macro.  This creates a static :c:type:`struct
-k_heap` variable with a given name that manages a memory region of the
+:c:macro:`K_HEAP_DEFINE` macro.  This creates a static :c:type:`k_heap` variable
+with a given name that manages a memory region of the
 specified size.
 
 Heaps can also be created to manage arbitrary regions of
@@ -46,9 +46,9 @@ returned by :cpp:func:`k_heap_alloc()` for the same heap.  Freeing a
 Low Level Heap Allocator
 ************************
 
-The underlying implementation of the :c:type:`struct k_heap`
-abstraction is provided a data structure named :c:type:`struct
-sys_heap`.  This implements exactly the same allocation semantics, but
+The underlying implementation of the :c:type:`k_heap`
+abstraction is provided a data structure named :c:type:`sys_heap`.  This
+implements exactly the same allocation semantics, but
 provides no kernel synchronization tools.  It is available for
 applications that want to manage their own blocks of memory in
 contexts (for example, userspace) where synchronization is unavailable
@@ -79,7 +79,7 @@ combined with adjacent free blocks to prevent fragmentation.
 All metadata is stored at the beginning of the contiguous block of
 heap memory, including the variable-length list of bucket list heads
 (which depend on heap size).  The only external memory required is the
-:c:type:`struct sys_heap` structure itself.
+:c:type:`sys_heap` structure itself.
 
 The ``sys_heap`` functions are unsynchronized.  Care must be taken by
 any users to prevent concurrent access.  Only one context may be

doc/reference/kernel/memory/pools.rst

@@ -5,12 +5,12 @@ Memory Pools
 
 .. note::
 
-    The ``k_mem_pool`` data structure defined here has been deprecated
+    The :c:type:`k_mem_pool` data structure defined here has been deprecated
     in current Zephyr code.  It still exists for applications which
     require the specific memory allocation and alignment patterns
     detailed below, but the default heap implementation (including the
-    default backend to the k_mem_pool APIs) is now a :c:type:`struct
-    k_heap` allocator, which is a better choice for general purpose
+    default backend to the k_mem_pool APIs) is now a :c:type:` k_heap`
+    allocator, which is a better choice for general purpose
     code.
 
 A :dfn:`memory pool` is a kernel object that allows memory blocks
@@ -119,7 +119,7 @@ Implementation
 Defining a Memory Pool
 ======================
 
-A memory pool is defined using a variable of type :c:type:`struct k_mem_pool`.
+A memory pool is defined using a variable of type :c:type:`k_mem_pool`.
 However, since a memory pool also requires a number of variable-size data
 structures to represent its block sets and the status of its quad-blocks,
 the kernel does not support the runtime definition of a memory pool.

doc/reference/kernel/memory/slabs.rst

@@ -67,7 +67,7 @@ Implementation
 Defining a Memory Slab
 ======================
 
-A memory slab is defined using a variable of type :c:type:`struct k_mem_slab`.
+A memory slab is defined using a variable of type :c:type:`k_mem_slab`.
 It must then be initialized by calling :cpp:func:`k_mem_slab_init()`.
 
 The following code defines and initializes a memory slab that has 6 blocks

doc/reference/kernel/other/polling.rst

@@ -68,7 +68,7 @@ Using k_poll()
 ==============
 
 The main API is :cpp:func:`k_poll()`, which operates on an array of poll events
-of type :c:type:`struct k_poll_event`. Each entry in the array represents one
+of type :c:type:`k_poll_event`. Each entry in the array represents one
 event a call to :cpp:func:`k_poll()` will wait for its condition to be
 fulfilled.
 
@@ -82,7 +82,7 @@ this). The user **tag** is optional and completely opaque to the API: it is
 there to help a user to group similar events together. Being optional, it is
 passed to the static initializer, but not the runtime ones for performance
 reasons. If using runtime initializers, the user must set it separately in the
-:c:type:`struct k_poll_event` data structure. If an event in the array is to be
+:c:type:`k_poll_event` data structure. If an event in the array is to be
 ignored, most likely temporarily, its type can be set to K_POLL_TYPE_IGNORE.
 
 .. code-block:: c
@@ -125,12 +125,12 @@ satisfied and not sooner.
 
 Only one thread can poll on a semaphore or a FIFO at a time. If a second thread
 tries to poll on the same semaphore or FIFO, :cpp:func:`k_poll()` immediately
-returns with the return value :c:macro:`-EADDRINUSE`. In that case, if other
+returns with the return value -:c:macro:`EADDRINUSE`. In that case, if other
 conditions passed to :cpp:func:`k_poll` were met, their state will be set in
 the corresponding poll event.
 
 In case of success, :cpp:func:`k_poll()` returns 0. If it times out, it returns
-:c:macro:`-EAGAIN`.
+-:c:macro:`EAGAIN`.
 
 .. code-block:: c
 
@@ -179,7 +179,7 @@ One of the types of events is :c:macro:`K_POLL_TYPE_SIGNAL`: this is a "direct"
 signal to a poll event. This can be seen as a lightweight binary semaphore only
 one thread can wait for.
 
-A poll signal is a separate object of type :c:type:`struct k_poll_signal` that
+A poll signal is a separate object of type :c:type:`k_poll_signal` that
 must be attached to a k_poll_event, similar to a semaphore or FIFO. It must
 first be initialized either via :c:macro:`K_POLL_SIGNAL_INITIALIZER()` or
 :cpp:func:`k_poll_signal_init()`.

doc/reference/kernel/other/ring_buffers.rst

@@ -117,7 +117,7 @@ Implementation
 Defining a Ring Buffer
 ======================
 
-A ring buffer is defined using a variable of type :c:type:`struct ring_buf`.
+A ring buffer is defined using a variable of type :c:type:`ring_buf`.
 It must then be initialized by calling :cpp:func:`ring_buf_init()`.
 
 The following code defines and initializes an empty **data item mode** ring

doc/reference/kernel/synchronization/mutexes.rst

@@ -93,7 +93,7 @@ Implementation
 Defining a Mutex
 ================
 
-A mutex is defined using a variable of type :c:type:`struct k_mutex`.
+A mutex is defined using a variable of type :c:type:`k_mutex`.
 It must then be initialized by calling :cpp:func:`k_mutex_init()`.
 
 The following code defines and initializes a mutex.

doc/reference/kernel/synchronization/semaphores.rst

@@ -47,7 +47,7 @@ Implementation
 Defining a Semaphore
 ====================
 
-A semaphore is defined using a variable of type :c:type:`struct k_sem`.
+A semaphore is defined using a variable of type :c:type:`k_sem`.
 It must then be initialized by calling :cpp:func:`k_sem_init()`.
 
 The following code defines a semaphore, then configures it as a binary

doc/reference/kernel/threads/index.rst

@@ -24,7 +24,7 @@ A thread has the following key properties:
   stack memory regions.
 
 * A **thread control block** for private kernel bookkeeping of the thread's
-  metadata. This is an instance of type :c:type:`struct k_thread`.
+  metadata. This is an instance of type :c:type:`k_thread`.
 
 * An **entry point function**, which is invoked when the thread is started.
   Up to 3 **argument values** can be passed to this function.

doc/reference/kernel/threads/workqueue.rst

@@ -179,7 +179,7 @@ Implementation
 Defining a Workqueue
 ====================
 
-A workqueue is defined using a variable of type :c:type:`struct k_work_q`.
+A workqueue is defined using a variable of type :c:type:`k_work_q`.
 The workqueue is initialized by defining the stack area used by its thread
 and then calling :cpp:func:`k_work_q_start()`. The stack area must be defined
 using :c:macro:`K_THREAD_STACK_DEFINE` to ensure it is properly set up in
@@ -202,7 +202,7 @@ The following code defines and initializes a workqueue.
 Submitting a Work Item
 ======================
 
-A work item is defined using a variable of type :c:type:`struct k_work`.
+A work item is defined using a variable of type :c:type:`k_work`.
 It must then be initialized by calling :cpp:func:`k_work_init()`.
 
 An initialized work item can be submitted to the system workqueue by
@@ -250,7 +250,7 @@ Submitting a Delayed Work Item
 ==============================
 
 A delayed work item is defined using a variable of type
-:c:type:`struct k_delayed_work`. It must then be initialized by calling
+:c:type:`k_delayed_work`. It must then be initialized by calling
 :cpp:func:`k_delayed_work_init()`.
 
 An initialized delayed work item can be submitted to the system workqueue by

doc/reference/kernel/timing/timers.rst

@@ -103,7 +103,7 @@ Implementation
 Defining a Timer
 ================
 
-A timer is defined using a variable of type :c:type:`struct k_timer`.
+A timer is defined using a variable of type :c:type:`k_timer`.
 It must then be initialized by calling :cpp:func:`k_timer_init()`.
 
 The following code defines and initializes a timer.

doc/reference/misc/notify.rst

@@ -21,7 +21,7 @@ API.
 A limitation is that this API is not suitable for :ref:`syscalls`
 because:
 
-* :c:type:`struct sys_notify` is not a kernel object;
+* :c:type:`sys_notify` is not a kernel object;
 * copying the notification content from userspace will break use of
   :c:macro:`CONTAINER_OF` in the implementing function;
 * neither the spin-wait nor callback notification methods can be
@@ -29,7 +29,7 @@ because:
 
 Where a notification is required for an asynchronous operation invoked
 from a user mode thread the subsystem or driver should provide a syscall
-API that uses :c:type:`struct k_poll_signal` for notification.
+API that uses :c:type:`k_poll_signal` for notification.
 
 API Reference
 *************

doc/reference/networking/lwm2m.rst

@@ -247,7 +247,7 @@ Sample usage
 ************
 
 To use the LwM2M library, start by creating an LwM2M client context
-:c:type:`struct lwm2m_ctx` structure:
+:c:type:`lwm2m_ctx` structure:
 
 .. code-block:: c
 

doc/reference/networking/net_l2.rst

@@ -12,12 +12,12 @@ Overview
 
 The L2 stack is designed to hide the whole networking link-layer part
 and the related device drivers from the upper network stack. This is made
-through a :c:type:`struct net_if` declared in
+through a :c:type:`net_if` declared in
 :zephyr_file:`include/net/net_if.h`.
 
 The upper layers are unaware of implementation details beyond the net_if
 object and the generic API provided by the L2 layer in
-:zephyr_file:`include/net/net_l2.h` as :c:type:`struct net_l2`.
+:zephyr_file:`include/net/net_l2.h` as :c:type:`net_l2`.
 
 Only the L2 layer can talk to the device driver, linked to the net_if
 object. The L2 layer dictates the API provided by the device driver,
@@ -39,7 +39,7 @@ See also :ref:`network stack architecture <network_stack_architecture>` for
 more details. The generic L2 API has these functions:
 
 - ``recv()``: All device drivers, once they receive a packet which they put
-  into a :c:type:`struct net_pkt`, will push this buffer to the network
+  into a :c:type:`net_pkt`, will push this buffer to the network
   stack via :c:func:`net_recv_data()`. At this point, the network
   stack does not know what to do with it. Instead, it passes the
   buffer along to the L2 stack's ``recv()`` function for handling.
@@ -69,13 +69,13 @@ basis. Please refer to :ref:`device_model_api`.
 
 There are, however, two differences:
 
-- The driver_api pointer must point to a valid :c:type:`struct net_if_api`
+- The driver_api pointer must point to a valid :c:type:`net_if_api`
   pointer.
 
 - The network device driver must use ``NET_DEVICE_INIT_INSTANCE()``
   or ``ETH_NET_DEVICE_INIT()`` for Ethernet devices. These
   macros will call the ``DEVICE_AND_API_INIT()`` macro, and also
-  instantiate a unique :c:type:`struct net_if` related to the created
+  instantiate a unique :c:type:`net_if` related to the created
   device driver instance.
 
 Implementing a network device driver depends on the L2 stack it
@@ -90,7 +90,7 @@ Ethernet device driver
 
 On reception, it is up to the device driver to fill-in the network packet with
 as many data buffers as required. The network packet itself is a
-:c:type:`struct net_pkt` and should be allocated through
+:c:type:`net_pkt` and should be allocated through
 :c:func:`net_pkt_rx_alloc_with_buffer()`. Then all data buffers will be
 automatically allocated and filled by :c:func:`net_pkt_write()`.
 
@@ -116,9 +116,8 @@ Device drivers for IEEE 802.15.4 L2 work basically the same as for
 Ethernet.  What has been described above, especially for ``recv()``, applies
 here as well.  There are two specific differences however:
 
-- It requires a dedicated device driver API: :c:type:`struct
-  ieee802154_radio_api`, which overloads :c:type:`struct
-  net_if_api`. This is because 802.15.4 L2 needs more from the device
+- It requires a dedicated device driver API: :c:type:`ieee802154_radio_api`,
+  which overloads :c:type:`net_if_api`. This is because 802.15.4 L2 needs more from the device
   driver than just ``send()`` and ``recv()`` functions.  This dedicated API is
   declared in :zephyr_file:`include/net/ieee802154_radio.h`. Each and every
   IEEE 802.15.4 device driver must provide a valid pointer on such
@@ -129,15 +128,15 @@ here as well.  There are two specific differences however:
   payload and frame checksum.  Buffers are meant to fit such
   frame size limitation.  But a buffer containing an IPv6/UDP packet
   might have more than one fragment. IEEE 802.15.4 drivers
-  handle only one buffer at a time.  This is why the :c:type:`struct
-  ieee802154_radio_api` requires a tx function pointer which differs
-  from the :c:type:`struct net_if_api` send function pointer.
+  handle only one buffer at a time.  This is why the
+  :c:type:`ieee802154_radio_api` requires a tx function pointer which differs
+  from the :c:type:`net_if_api` send function pointer.
   Instead, the IEEE 802.15.4 L2, provides a generic
   :c:func:`ieee802154_radio_send()` meant to be given as
-  :c:type:`struct net_if` send function. It turn, the implementation
+  :c:type:`net_if` send function. It turn, the implementation
   of :c:func:`ieee802154_radio_send()` will ensure the same behavior:
-  sending one buffer at a time through :c:type:`struct
-  ieee802154_radio_api` tx function, and unreferencing the network packet
+  sending one buffer at a time through :c:type:`ieee802154_radio_api` tx
+  function, and unreferencing the network packet
   only when all the transmission were successful.
 
 Each IEEE 802.15.4 device driver, in the end, will need to call

doc/reference/networking/net_pkt.rst

@@ -74,7 +74,7 @@ Buffer allocation
 =================
 
 The net_pkt object does not define its own buffer, but instead uses an
-existing object for this: :c:type:`struct net_buf`. (See
+existing object for this: :c:type:`net_buf`. (See
 :ref:`net_buf_interface` for more information). However, it mostly
 hides the usage of such a buffer because net_pkt brings network
 awareness to buffer allocation and, as we will see later, its

doc/reference/peripherals/sensor.rst

@@ -29,7 +29,7 @@ description and units of measurement:
 Values
 ======
 
-Sensor devices return results as :c:type:`struct sensor_value`.  This
+Sensor devices return results as :c:type:`sensor_value`.  This
 representation avoids use of floating point values as they may not be
 supported on certain setups.
 
@@ -41,7 +41,7 @@ application instructs the driver to fetch a sample of all its channels.
 Then, individual channels may be read.  In the case of channels with
 multiple axes, they can be read in a single operation by supplying
 the corresponding :literal:`_XYZ` channel type and a buffer of 3
-:c:type:`struct sensor_value` objects.  This approach ensures consistency
+:c:type:`sensor_value` objects.  This approach ensures consistency
 of channels between reads and efficiency of communication by issuing a
 single transaction on the underlying bus.
 
@@ -55,8 +55,8 @@ compensates data for both channels.
    :lines: 12-
    :linenos:
 
-The example assumes that the returned values have type :c:type:`struct
-sensor_value`, which is the case for BME280.  A real application
+The example assumes that the returned values have type :c:type:`sensor_value`,
+which is the case for BME280.  A real application
 supporting multiple sensors should inspect the :c:data:`type` field of
 the :c:data:`temp` and :c:data:`press` values and use the other fields
 of the structure accordingly.
@@ -89,9 +89,9 @@ Many sensor chips support one or more triggers. Some examples of triggers
 include: new data is ready for reading, a channel value has crossed a
 threshold, or the device has sensed motion.
 
-To configure a trigger, an application needs to supply a :c:type:`struct
-sensor_trigger` and a handler function.  The structure contains the trigger
-type and the channel on which the trigger must be configured.
+To configure a trigger, an application needs to supply a
+:c:type:`sensor_trigger` and a handler function.  The structure contains the
+trigger type and the channel on which the trigger must be configured.
 
 Because most sensors are connected via SPI or I2C busses, it is not possible
 to communicate with them from the interrupt execution context.  The

doc/reference/usermode/kernelobjects.rst

@@ -6,7 +6,7 @@ Kernel Objects
 A kernel object can be one of three classes of data:
 
 * A core kernel object, such as a semaphore, thread, pipe, etc.
-* A thread stack, which is an array of :c:type:`struct z_thread_stack_element`
+* A thread stack, which is an array of :c:type:`z_thread_stack_element`
   and declared with :c:macro:`K_THREAD_STACK_DEFINE()`
 * A device driver instance (struct device) that belongs to one of a defined
   set of subsystems
@@ -109,14 +109,14 @@ When a system call is made and the kernel is presented with a memory address
 of what may or may not be a valid kernel object, the address can be validated
 with a constant-time lookup in this table.
 
-Drivers are a special case. All drivers are instances of :c:type:`struct
-device`, but it is important to know what subsystem a driver belongs to so that
+Drivers are a special case. All drivers are instances of :c:type:`device`, but
+it is important to know what subsystem a driver belongs to so that
 incorrect operations, such as calling a UART API on a sensor driver object, can
 be prevented. When a device struct is found, its API pointer is examined to
 determine what subsystem the driver belongs to.
 
 The table itself maps kernel object memory addresses to instances of
-:c:type:`struct z_object`, which has all the metadata for that object. This
+:c:type:`z_object`, which has all the metadata for that object. This
 includes:
 
 * A bitfield indicating permissions on that object. All threads have a
@@ -129,7 +129,7 @@ includes:
 * A set of flags for that object. This is currently used to track
   initialization state and whether an object is public or not.
 * An extra data field. The semantics of this field vary by object type, see
-  the definition of :c:type:`union z_object_data`.
+  the definition of :c:type:`z_object_data`.
 
 Dynamic objects allocated at runtime are tracked in a runtime red/black tree
 which is used in parallel to the gperf table when validating object pointers.
@@ -250,7 +250,7 @@ Instances of the new struct should now be tracked.
 Creating New Driver Subsystem Kernel Objects
 ============================================
 
-All driver instances are :c:type:`struct device`. They are differentiated by
+All driver instances are :c:type:`device`. They are differentiated by
 what API struct they are set to.
 
 * In ``scripts/gen_kobject_list.py``, add the name of the API struct for the

doc/reference/usermode/memory_domain.rst

@@ -324,7 +324,7 @@ Create a Memory Domain
 ----------------------
 
 A memory domain is defined using a variable of type
-:c:type:`struct k_mem_domain`. It must then be initialized by calling
+:c:type:`k_mem_domain`. It must then be initialized by calling
 :cpp:func:`k_mem_domain_init()`.
 
 The following code defines and initializes an empty memory domain.

include/kernel.h

@@ -4299,7 +4299,7 @@ struct k_pipe {
 	struct {
 		_wait_q_t      readers; /**< Reader wait queue */
 		_wait_q_t      writers; /**< Writer wait queue */
-	} wait_q;
+	} wait_q;			/** Wait queue */
 
 	_OBJECT_TRACING_NEXT_PTR(k_pipe)
 	_OBJECT_TRACING_LINKED_FLAG