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iPod Classic: update timer API using 32-bit timers.

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Change-Id: I49dab8ae955a339ad0a27402fa21caa411c4ecf6
Reviewed-on: http://gerrit.rockbox.org/1032
Reviewed-by: Marcin Bukat <marcin.bukat@gmail.com>
This commit is contained in:
Cástor Muñoz 2014-11-10 02:39:16 +01:00 • committed by Marcin Bukat
parent 229a02a4ee
commit 57969698ce
3 changed files with 69 additions and 47 deletions
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57
firmware/target/arm/s5l8702/timer-s5l8702.c
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@ -26,13 +26,11 @@
#include "system.h"
#include "timer.h"
//TODO: This needs calibration once we figure out the clocking
void INT_TIMERC(void)
void INT_TIMERF(void)
{
/* clear interrupt */
TCCON = TCCON;
TSTAT = (0x07 << 16);
if (pfn_timer != NULL) {
pfn_timer();
}
@ -40,12 +38,8 @@ void INT_TIMERC(void)
bool timer_set(long cycles, bool start)
{
static const int cs_table[] = {1, 2, 4, 6};
int prescale, cs;
long count;
/* stop and clear timer */
TCCMD = (1 << 1); /* TD_CLR */
/* stop timer */
TFCMD = (0 << 0); /* TF_ENABLE */
/* optionally unregister any previously registered timer user */
if (start) {
@ -55,40 +49,33 @@ bool timer_set(long cycles, bool start)
}
}
/* scale the count down with the clock select */
for (cs = 0; cs < 4; cs++) {
count = cycles >> cs_table[cs];
if ((count < 65536) || (cs == 3)) {
break;
}
}
/* scale the count down with the prescaler */
prescale = 1;
while (count >= 65536) {
count >>= 1;
prescale <<= 1;
}
/* There is an odd behaviour when the 32-bit timers are launched
for the first time, the interrupt status bits are set and an
unexpected interrupt is generated if they are enabled. A way to
workaround this is to write the data registers before clearing
the counter. */
TFDATA0 = cycles;
TFCMD = (1 << 1); /* TF_CLR */
/* configure timer */
TCCON = (1 << 12) | /* TD_INT0_EN */
(cs << 8) | /* TS_CS */
(0 << 4); /* TD_MODE_SEL, 0 = interval mode */
TCPRE = prescale - 1;
TCDATA0 = count;
TCCMD = (1 << 0); /* TD_ENABLE */
TFCON = (1 << 12) | /* TF_INT0_EN */
(4 << 8) | /* TF_CS, 4 = ECLK / 1 */
(1 << 6) | /* use ECLK (12MHz) */
(0 << 4); /* TF_MODE_SEL, 0 = interval mode */
TFPRE = 0; /* no prescaler */
TFCMD = (1 << 0); /* TF_ENABLE */
return true;
}
bool timer_start(void)
{
TCCMD = (1 << 0); /* TD_ENABLE */
TFCMD = (1 << 0); /* TF_ENABLE */
return true;
}
void timer_stop(void)
{
TCCMD = (0 << 0); /* TD_ENABLE */
TFCMD = (0 << 0); /* TF_ENABLE */
}