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Tiva Timers: Add interfaces to read the current timer value

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This commit is contained in:
Gregory Nutt 2015-01-12 09:18:38 -06:00
parent 9d64fc6fcf
commit 487f9a3be9
2 changed files with 176 additions and 7 deletions
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134
arch/arm/src/tiva/tiva_timer.c
View File

@ -1958,6 +1958,131 @@ void tiva_timer16_stop(TIMER_HANDLE handle, int tmndx)
tiva_gptm_modifyreg(handle, TIVA_TIMER_CTL_OFFSET, clrbits, 0);
}
/****************************************************************************
* Name: tiva_timer16_counter
*
* Description:
* Return the current 24-bit counter value of the 16-bit timer.
*
* The timer 24-bit value is the 16-bit counter value AND the 8-bit
* prescaler value. From the caller's point of view the match value is
* the 24-bit timer at the timer input clock frequency.
*
* When counting down in periodic modes, the prescaler contains the
* least-significant bits of the count. When counting up, the prescaler
* holds the most-significant bits of the count. But the caller is
* protected from this complexity.
*
* Input Parameters:
* handle - The handle value returned by tiva_gptm_configure()
* tmndx - Either TIMER16A or TIMER16B to select the 16-bit timer
*
* Returned Value:
* The current 24-bit counter value.
*
****************************************************************************/
uint32_t tiva_timer16_counter(TIMER_HANDLE handle, int tmndx)
{
struct tiva_gptmstate_s *priv = (struct tiva_gptmstate_s *)handle;
const struct tiva_gptm16config_s *gptm;
const struct tiva_timer16config_s *config;
irqstate_t flags;
uintptr_t base;
uintptr_t timerr;
uintptr_t prescr;
uint32_t timerv;
uint32_t prescv;
uint32_t checkv;
uint32_t counter;
DEBUGASSERT(priv && priv->attr && priv->config &&
priv->config->mode == TIMER16_MODE && (unsigned)tmndx < 2);
/* Get settings common to both 16-bit timers */
gptm = (const struct tiva_gptm16config_s *)priv->config;
base = priv->attr->base;
/* Get settings unique to one of the 16-bit timers */
if (tmndx)
{
/* Get the Timer B configuration */
config = &gptm->config[TIMER16B];
/* Get Timer B register addresses */
timerr = base + TIVA_TIMER_TBR_OFFSET;
prescr = base + TIVA_TIMER_TBPR_OFFSET;
}
else
{
/* Get the Timer A configuration */
config = &gptm->config[TIMER16A];
/* Get Timer A register addresses */
timerr = base + TIVA_TIMER_TAR_OFFSET;
prescr = base + TIVA_TIMER_TAPR_OFFSET;
}
/* Are we counting up or down? */
if (TIMER_ISCOUNTUP(config))
{
/* We are counting up. The prescaler holds the most-significant bits of
* the count. Sample these registers until we are assured that there
* is no roll-over from the counter to the prescaler register.
*/
do
{
flags = irqsave();
checkv = getreg32(prescr);
timerv = getreg32(timerr);
prescv = getreg32(prescr);
irqrestore(flags);
}
while (checkv != prescv);
/* Then form the 32-bit counter value with the prescaler as the most
* significant 8-bits.
*/
counter = (prescv & 0xff) << 16 | (timerv & 0xffff);
}
else
{
/* We are counting down. The prescaler contains the least-significant
* bits of the count. Sample these registers until we are assured that
* there is no roll-over from the counter to the counter register.
*/
do
{
flags = irqsave();
checkv = getreg32(timerr);
prescv = getreg32(prescr);
timerv = getreg32(timerr);
irqrestore(flags);
}
while (checkv != timerv);
/* Then form the 32-bit counter value with the counter as the most
* significant 8-bits.
*/
counter = (timerv & 0xffff) << 8 | (prescv & 0xff);
}
/* Return the counter value */
return counter;
}
/****************************************************************************
* Name: tiva_rtc_setalarm
*
@ -2161,8 +2286,8 @@ void tiva_timer32_relmatch(TIMER_HANDLE handle, uint32_t relmatch)
* periodic timer.
*
* NOTE: The relmatch input is a really a 24-bit value; it is the 16-bit
* match counter match value AND the 8-bit prescaler value. From the
* callers point of view the match value is the 24-bit time to match
* match counter match value AND the 8-bit prescaler match value. From
* the caller's point of view the match value is the 24-bit time to match
* driven at the timer input clock frequency.
*
* When counting down in periodic modes, the prescaler contains the
@ -2208,8 +2333,7 @@ void tiva_timer16_relmatch(TIMER_HANDLE handle, uint32_t relmatch, int tmndx)
DEBUGASSERT(priv && priv->attr && priv->config &&
priv->config->mode == TIMER16_MODE && (unsigned)tmndx < 2);
/* Precalculate as much as possible before entering the critical section */
/* Pre-calculate as much as possible before entering the critical section */
gptm = (const struct tiva_gptm16config_s *)priv->config;
base = priv->attr->base;
@ -2249,7 +2373,7 @@ void tiva_timer16_relmatch(TIMER_HANDLE handle, uint32_t relmatch, int tmndx)
priv->imr |= TIMER_INT_TAM;
}
/* Get Timer B register addresses */
/* Get Timer A register addresses */
timerr = base + TIVA_TIMER_TAR_OFFSET;
prescr = base + TIVA_TIMER_TAPR_OFFSET;

49
arch/arm/src/tiva/tiva_timer.h
View File

@ -458,6 +458,51 @@ void tiva_timer16_stop(TIMER_HANDLE handle, int tmndx);
#define tiva_timer16a_stop(h) tiva_timer16_stop(h, TIMER16A)
#define tiva_timer16b_stop(h) tiva_timer16_stop(h, TIMER16B)
/****************************************************************************
* Name: tiva_timer32_counter
*
* Description:
* Return the current 32-bit counter value of the 32-bit timer.
*
* Input Parameters:
* handle - The handle value returned by tiva_gptm_configure()
*
* Returned Value:
* The current 32-bit counter value.
*
****************************************************************************/
static inline uint32_t tiva_timer32_counter(TIMER_HANDLE handle)
{
return tiva_gptm_getreg(handle, TIVA_TIMER_TAR_OFFSET);
}
/****************************************************************************
* Name: tiva_timer16_counter
*
* Description:
* Return the current 24-bit counter value of the 16-bit timer.
*
* The timer 24-bit value is the 16-bit counter value AND the 8-bit
* prescaler value. From the caller's point of view the match value is
* the 24-bit timer at the timer input clock frequency.
*
* When counting down in periodic modes, the prescaler contains the
* least-significant bits of the count. When counting up, the prescaler
* holds the most-significant bits of the count. But the caller is
* protected from this complexity.
*
* Input Parameters:
* handle - The handle value returned by tiva_gptm_configure()
* tmndx - Either TIMER16A or TIMER16B to select the 16-bit timer
*
* Returned Value:
* The current 24-bit counter value.
*
****************************************************************************/
uint32_t tiva_timer16_counter(TIMER_HANDLE handle, int tmndx);
/****************************************************************************
* Name: tiva_timer32_setload
*
@ -676,8 +721,8 @@ void tiva_timer32_relmatch(TIMER_HANDLE handle, uint32_t relmatch);
* runnning, periodic timer.
*
* NOTE: The relmatch input is a really a 24-bit value; it is the 16-bit
* match counter match value AND the 8-bit prescaler value. From the
* callers point of view the match value is the 24-bit time to match
* match counter match value AND the 8-bit prescaler match value. From
* the caller's point of view the match value is the 24-bit time to match
* driven at the timer input clock frequency.
*
* When counting down in periodic modes, the prescaler contains the