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bsp-howto: Document clock driver arg parameter

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Close #4862.
This commit is contained in:
Sebastian Huber
2024-03-22 08:10:14 +01:00
parent 150c2e8b55
commit 7fafbede33
1 changed files with 22 additions and 12 deletions
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34
bsp-howto/clock.rst
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@@ -139,6 +139,9 @@ Simple Timecounter Variant
For an example see the `ERC32 clock driver
<https://git.rtems.org/rtems/tree/bsps/sparc/erc32/clock/ckinit.c>`_.
The argument parameter of ``Clock_driver_timecounter_tick( arg )`` is the
argument used to install the clock interrupt handler. Device drivers may use
this argument to access their control state.
.. code-block:: c
@@ -165,9 +168,9 @@ For an example see the `ERC32 clock driver
);
}
static void some_tc_tick( void )
static void some_tc_tick( rtems_timecounter_simple *tc )
{
rtems_timecounter_simple_downcounter_tick( &some_tc, some_tc_get );
rtems_timecounter_simple_downcounter_tick( tc, some_tc_get );
}
static void some_support_initialize_hardware( void )
@@ -193,8 +196,8 @@ For an example see the `ERC32 clock driver
#define Clock_driver_support_initialize_hardware() \
some_support_initialize_hardware()
#define Clock_driver_timecounter_tick() \
some_tc_tick()
#define Clock_driver_timecounter_tick( arg ) \
some_tc_tick( arg )
#include "../../../shared/dev/clock/clockimpl.h"
@@ -224,15 +227,20 @@ Install Clock Tick Interrupt Service Routine
============================================
The clock driver may provide a function to install the clock tick interrupt
service routine via ``Clock_driver_support_install_isr()``. The clock tick
interrupt service routine is passed as the one and only parameter to this
macro. The default implementation will do nothing.
service routine via ``Clock_driver_support_install_isr( isr )``. The clock
tick interrupt service routine is passed as the one and only parameter to this
macro. The default implementation will do nothing. The argument parameter (in
the code below ``&some_instance``) for the installed interrupt handler is
available in the ``Clock_driver_support_at_tick( arg )`` and
``Clock_driver_support_initialize_hardware( arg )`` customization macros.
.. code-block:: c
#include <bsp/irq.h>
#include <bsp/fatal.h>
static some_control some_instance;
static void some_support_install_isr( rtems_interrupt_handler isr )
{
rtems_status_code sc;
@@ -241,7 +249,7 @@ macro. The default implementation will do nothing.
"Clock",
RTEMS_INTERRUPT_UNIQUE,
isr,
NULL
&some_instance
);
if ( sc != RTEMS_SUCCESSFUL ) {
bsp_fatal( SOME_FATAL_IRQ_INSTALL );
@@ -257,17 +265,19 @@ Support At Tick
===============
The hardware-specific support at tick is specified by
``Clock_driver_support_at_tick()``.
``Clock_driver_support_at_tick( arg )``. The ``arg`` is the argument used to
install the clock interrupt handler. Device drivers may use this argument to
access their control state.
.. code-block:: c
static void some_support_at_tick( void )
static void some_support_at_tick( some_control *arg )
{
/* Clear interrupt */
}
#define Clock_driver_support_at_tick() \
some_support_at_tick()
#define Clock_driver_support_at_tick( arg ) \
some_support_at_tick( arg )
#include "../../../shared/dev/clock/clockimpl.h"