diff options
Diffstat (limited to 'bsp-howto/clock.rst')
| -rw-r--r-- | bsp-howto/clock.rst | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/bsp-howto/clock.rst b/bsp-howto/clock.rst index f3d30ce..ed83472 100644 --- a/bsp-howto/clock.rst +++ b/bsp-howto/clock.rst @@ -65,8 +65,8 @@ Clock Tick Only Initialization ============== -The clock driver is initialized by a dedicated system initialization handler if -requested by the application configuration option +The clock driver is initialized by the ``_Clock_Initialize()`` system +initialization handler if requested by the application configuration option ``CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER``. The clock driver does not use the legacy IO driver framework. @@ -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" |