[PATCH 4/4] bsp clock configs
Gedare Bloom
gedare at rtems.org
Wed Apr 1 15:04:36 UTC 2015
This patch could use some more explanation, and probably some
documentation in the BSP guide. Why is erc32 being changed, for what
purpose?
On Wed, Apr 1, 2015 at 10:37 AM, Alexander Krutwig
<alexander.krutwig at embedded-brains.de> wrote:
> ---
> c/src/lib/libbsp/shared/clockdrv_shell.h | 31 ++++++++++++-----
> c/src/lib/libbsp/sparc/erc32/clock/ckinit.c | 54 +++++++++++++++++++++++------
> 2 files changed, 66 insertions(+), 19 deletions(-)
>
> diff --git a/c/src/lib/libbsp/shared/clockdrv_shell.h b/c/src/lib/libbsp/shared/clockdrv_shell.h
> index 5dbea13..cf3237d 100644
> --- a/c/src/lib/libbsp/shared/clockdrv_shell.h
> +++ b/c/src/lib/libbsp/shared/clockdrv_shell.h
> @@ -20,6 +20,10 @@
> #include <bsp.h>
> #include <rtems/clockdrv.h>
>
> +#ifdef Clock_driver_nanoseconds_since_last_tick
> +#error "adjust your clock driver"
Please make error message more informative. I have no idea what it
should be adjusted to.
> +#endif
> +
> /**
> * @defgroup bsp_clock Clock Support
> *
> @@ -39,6 +43,14 @@
> #define Clock_driver_support_find_timer()
> #endif
>
> +/*
> + * A specialized clock driver may use for example _Timecounter_Tick_simple()
> + * instead of the default.
> + */
> +#ifndef Clock_driver_timecounter_tick
> + Clock_driver_timecounter_tick() _Timecounter_Tick()
> +#endif
> +
> /**
> * @brief ISRs until next clock tick
> */
> @@ -53,6 +65,12 @@ volatile uint32_t Clock_driver_ticks;
>
> void Clock_exit( void );
>
> +static void Clock_tick( void )
> +{
> + Clock_driver_timecounter_tick();
> + rtems_clock_tick();
> +}
> +
> /**
> * @brief Clock_isr
> *
> @@ -79,7 +97,7 @@ rtems_isr Clock_isr(
>
> #if CLOCK_DRIVER_USE_FAST_IDLE
> do {
> - rtems_clock_tick();
> + Clock_tick();
> } while (
> _Thread_Heir == _Thread_Executing
> && _Thread_Executing->Start.entry_point
> @@ -101,7 +119,7 @@ rtems_isr Clock_isr(
> * The driver is multiple ISRs per clock tick.
> */
> if ( !Clock_driver_isrs ) {
> - rtems_clock_tick();
> + Clock_tick();
>
> Clock_driver_isrs = CLOCK_DRIVER_ISRS_PER_TICK;
> }
> @@ -110,7 +128,7 @@ rtems_isr Clock_isr(
> /*
> * The driver is one ISR per clock tick.
> */
> - rtems_clock_tick();
> + Clock_tick();
> #endif
> #endif
> }
> @@ -149,6 +167,7 @@ rtems_device_driver Clock_initialize(
>
> Clock_driver_ticks = 0;
>
> +
> /*
> * Find timer -- some BSPs search buses for hardware timer
> */
> @@ -160,12 +179,6 @@ rtems_device_driver Clock_initialize(
> (void) Old_ticker;
> Clock_driver_support_install_isr( Clock_isr, Old_ticker );
>
> - #if defined(Clock_driver_nanoseconds_since_last_tick)
> - rtems_clock_set_nanoseconds_extension(
> - Clock_driver_nanoseconds_since_last_tick
> - );
> - #endif
> -
> /*
> * Now initialize the hardware that is the source of the tick ISR.
> */
> diff --git a/c/src/lib/libbsp/sparc/erc32/clock/ckinit.c b/c/src/lib/libbsp/sparc/erc32/clock/ckinit.c
> index 2afe770..1fb186c 100644
> --- a/c/src/lib/libbsp/sparc/erc32/clock/ckinit.c
> +++ b/c/src/lib/libbsp/sparc/erc32/clock/ckinit.c
> @@ -25,6 +25,7 @@
> #include <bsp.h>
> #include <bspopts.h>
> #include <rtems/counter.h>
> +#include <rtems/score/timecounterimpl.h>
>
> #if SIMSPARC_FAST_IDLE==1
> #define CLOCK_DRIVER_USE_FAST_IDLE 1
> @@ -44,25 +45,33 @@
>
> extern int CLOCK_SPEED;
>
> -static uint32_t bsp_clock_nanoseconds_since_last_tick(void)
> +static struct timecounter erc32_tc;
> +
> +static uint64_t erc32_tc_scaler;
> +
> +static uint32_t erc32_tc_interval;
> +
> +static uint32_t erc32_tc_current(void)
> +{
> + return (ERC32_MEC.Real_Time_Clock_Counter * erc32_tc_scaler) >> 32;
> +}
> +
> +static u_int erc32_get_timecount(struct timecounter *tc)
> {
> uint32_t clicks;
> - uint32_t usecs;
> + uint32_t interval;
>
> - clicks = ERC32_MEC.Real_Time_Clock_Counter;
> + interval = erc32_tc_interval;
> + clicks = erc32_tc_current();
>
> if ( ERC32_Is_interrupt_pending( ERC32_INTERRUPT_REAL_TIME_CLOCK ) ) {
> - clicks = ERC32_MEC.Real_Time_Clock_Counter;
> - usecs = (2*rtems_configuration_get_microseconds_per_tick() - clicks);
> + clicks = erc32_tc_current();
> + return (2 * interval - clicks);
> } else {
> - usecs = (rtems_configuration_get_microseconds_per_tick() - clicks);
> + return (interval - clicks);
> }
> - return usecs * 1000;
> }
>
> -#define Clock_driver_nanoseconds_since_last_tick \
> - bsp_clock_nanoseconds_since_last_tick
> -
> static CPU_Counter_ticks erc32_counter_difference(
> CPU_Counter_ticks second,
> CPU_Counter_ticks first
> @@ -75,6 +84,7 @@ static CPU_Counter_ticks erc32_counter_difference(
>
> #define Clock_driver_support_initialize_hardware() \
> do { \
> + uint32_t mask; \
> /* approximately 1 us per countdown */ \
> ERC32_MEC.Real_Time_Clock_Scalar = CLOCK_SPEED - 1; \
> ERC32_MEC.Real_Time_Clock_Counter = \
> @@ -89,7 +99,18 @@ static CPU_Counter_ticks erc32_counter_difference(
> ERC32_MEC_Set_Real_Time_Clock_Timer_Control( \
> ERC32_MEC_TIMER_COUNTER_ENABLE_COUNTING | \
> ERC32_MEC_TIMER_COUNTER_RELOAD_AT_ZERO \
> + ); \
> + _Timecounter_Get_binary_scaler_and_mask( \
> + rtems_configuration_get_microseconds_per_tick(), \
> + &erc32_tc_scaler, \
> + &mask \
> ); \
> + erc32_tc_interval = (mask + 1) / 2; \
> + erc32_tc.tc_get_timecount = erc32_get_timecount; \
> + erc32_tc.tc_counter_mask = mask; \
> + erc32_tc.tc_frequency = (1000000 * erc32_tc_scaler) >> 32; \
> + erc32_tc.tc_quality = TIMECOUNTER_DEFAULT_DRIVER_QUALITY; \
> + _Timecounter_Install(&erc32_tc); \
> _SPARC_Counter_initialize( \
> &ERC32_MEC.Real_Time_Clock_Counter, \
> erc32_counter_difference \
> @@ -97,6 +118,19 @@ static CPU_Counter_ticks erc32_counter_difference(
> rtems_counter_initialize_converter(1000000); \
> } while (0)
>
> +static void erc32_tc_tick(void)
> +{
> + uint32_t clicks;
> + uint32_t interval;
> +
> + interval = erc32_tc_interval;
> + clicks = interval - erc32_tc_current();
> +
> + _Timecounter_Tick_simple(interval + clicks, clicks);
> +}
> +
> +#define Clock_driver_timecounter_tick() erc32_tc_tick()
> +
> #define Clock_driver_support_shutdown_hardware() \
> do { \
> ERC32_Mask_interrupt( ERC32_INTERRUPT_REAL_TIME_CLOCK ); \
> --
> 1.8.4.5
>
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