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[platform][stellaris] get systick firing properly

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This commit is contained in:
Travis Geiselbrecht
2013-02-17 18:41:27 -08:00
parent 4b403554e8
commit 70b074bf6f
3 changed files with 20 additions and 14 deletions
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1
platform/stellaris/include/ti_driverlib.h
View File

@@ -52,7 +52,6 @@ __BEGIN_CDECLS
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/sysctl.h"
#include "driverlib/systick.h"
#include "driverlib/uart.h"
__END_CDECLS

4
platform/stellaris/ti/rules.mk
View File

@@ -26,9 +26,11 @@ MODULE_SRCS += \
$(LOCAL_DIR)/driverlib/ssi.c \
$(LOCAL_DIR)/driverlib/sysctl.c \
$(LOCAL_DIR)/driverlib/sysexc.c \
$(LOCAL_DIR)/driverlib/systick.c \
$(LOCAL_DIR)/driverlib/timer.c \
$(LOCAL_DIR)/driverlib/uart.c \
$(LOCAL_DIR)/driverlib/udma.c \
$(LOCAL_DIR)/driverlib/usb.c \
$(LOCAL_DIR)/driverlib/watchdog.c
# UNUSED
# $(LOCAL_DIR)/driverlib/systick.c

29
platform/stellaris/timer.c
View File

@@ -31,13 +31,12 @@
#include <inc/hw_types.h>
#include "ti_driverlib.h"
#define MCLK 84000000 /* XXX read this */
#define TICK_RATE (MCLK / 2)
#define LOCAL_TRACE 0
static volatile uint64_t ticks = 0;
static uint32_t tick_rate_mhz = 0;
static platform_timer_callback cb;
static void *cb_args;
@@ -47,6 +46,7 @@ void _systick(void)
inc_critical_section();
bool resched = false;
ticks += 10000;
if (cb) {
lk_time_t now = current_time();
if (cb(cb_args, now) == INT_RESCHEDULE)
@@ -65,15 +65,21 @@ status_t platform_set_periodic_timer(platform_timer_callback callback, void *arg
{
LTRACEF("callback %p, arg %p, interval %ld\n", callback, arg, interval);
enter_critical_section();
cb = callback;
cb_args = arg;
cm3_systick_set_periodic(/* XXX */ MCLK, interval);
uint32_t clock_rate = SysCtlClockGet();
tick_rate_mhz = clock_rate / 1000000;
cm3_systick_set_periodic(clock_rate, interval);
exit_critical_section();
return NO_ERROR;
}
lk_time_t current_time(void)
{
return current_time_hires() / 1000;
@@ -81,32 +87,31 @@ lk_time_t current_time(void)
lk_bigtime_t current_time_hires(void)
{
uint32_t reload = SysTick->LOAD & SysTick_LOAD_RELOAD_Msk;
uint64_t t;
uint32_t delta;
do {
t = ticks;
uint16_t delta = SysTickValueGet();
delta = (volatile uint32_t)SysTick->VAL;
if (ticks != t)
continue;
t += delta;
} while (0);
/* convert ticks to usec */
lk_bigtime_t res = t / (TICK_RATE / 1000000);
delta = (reload - delta) / tick_rate_mhz;
lk_bigtime_t res = t + delta;
return res;
}
void stellaris_timer_early_init(void)
{
SysTickPeriodSet(SysCtlClockGet() / TICK_RATE);
}
void stellaris_timer_init(void)
{
SysTickIntEnable();
SysTickEnable();
}