doc: remove device_sync_call documentation
This is obsolete and not available anymore in the unified kernel.
Change-Id: I39f6afd5285a2286fe954bd8dc501f888d0d9003
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
diff --git a/doc/drivers/drivers.rst b/doc/drivers/drivers.rst
index d90951b..197f829 100644
--- a/doc/drivers/drivers.rst
+++ b/doc/drivers/drivers.rst
@@ -53,43 +53,6 @@
or spi.h, are usually intended as synchronous. Thus, these calls should be
blocking.
-Due to the fact that Zephyr provides two types of execution contexts (task
-and fiber) on a microkernel, drivers need to act accordingly. For example, a
-nanokernel semaphore cannot be used when the context is a task, so the
-:file:`include/device.h` exposes a helper API to handle this case transparently;
-no other means ought to be used instead.
-
-Zephyr API exposes 1 type and 3 inline functions to solve this issue.
-
-``device_sync_call_t``
-
- This type provides a nanokernel semaphore, always present in both nanokernel
- and microkernel use cases. It is meant to be used within a fiber context.
- Then, and only on a microkernel type, it will provide a kernel semaphore
- meant to be used within a task context. A boolean marker is used to remember
- the caller's context when running a microkernel.
-
-:cpp:func:`device_sync_call_init()`
-
- This function initializes the ``device_sync_call_t`` type semaphores and the
- marker. This function should be used only once in the device driver's instance
- lifetime. Thus, the driver's initialization function is the best place for
- calling it.
-
-:cpp:func:`device_sync_call_wait()`
-
- This function will block - that is, it will perform a "take wait" - on the
- relevant semaphore. The exposed driver's API function can then be used as a
- blocking function until the relevant semaphore is released by a ``give``.
- This is therefore used to start a synchronous call, and waits until being
- signaled for synchronization.
-
-:cpp:func:`device_sync_call_complete()`
-
- This function releases the relevant semaphore and thus will unlock the blocking
- function. Most frequently will it be called in the driver's ISR handler. It is
- used to signal the completion of the synchronous call (error or success).
-
Driver APIs
***********
