/*
* Clockevent device: interrupts every 1/HZ (== pit_cycles * MCK/16)
*/
static void
pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
{
unsigned long flags;
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
case CLOCK_EVT_MODE_RESUME:
/* update clocksource counter, then enable the IRQ */
raw_local_irq_save(flags);
pit_cnt += pit_cycle * PIT_PICNT(at91_sys_read(AT91_PIT_PIVR));
at91_sys_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN
| AT91_PIT_PITIEN);
raw_local_irq_restore(flags);
break;
case CLOCK_EVT_MODE_ONESHOT:
BUG();
/* FALLTHROUGH */
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
/* disable irq, leaving the clocksource active */
at91_sys_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
break;
}
}
/*
* IRQ handler for the timer.
*/
static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id)
{
/*
* irqs should be disabled here, but as the irq is shared they are only
* guaranteed to be off if the timer irq is registered first.
*/
WARN_ON_ONCE(!irqs_disabled());
/* The PIT interrupt may be disabled, and is shared */
if ((pit_clkevt.mode == CLOCK_EVT_MODE_PERIODIC)
&& (pit_read(AT91_PIT_SR) & AT91_PIT_PITS)) {
unsigned nr_ticks;
/* Get number of ticks performed before irq, and ack it */
nr_ticks = PIT_PICNT(pit_read(AT91_PIT_PIVR));
do {
pit_cnt += pit_cycle;
pit_clkevt.event_handler(&pit_clkevt);
nr_ticks--;
} while (nr_ticks);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
/*
* Clockevent device: interrupts every 1/HZ (== pit_cycles * MCK/16)
*/
static void
pit_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
{
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* Set up irq handler */
setup_irq(AT91_ID_SYS, &at91sam926x_pit_irq);
/* update clocksource counter */
pit_cnt += pit_cycle * PIT_PICNT(at91_sys_read(AT91_PIT_PIVR));
at91_sys_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN
| AT91_PIT_PITIEN);
break;
case CLOCK_EVT_MODE_ONESHOT:
BUG();
/* FALLTHROUGH */
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
/* disable irq, leaving the clocksource active */
at91_sys_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
remove_irq(AT91_ID_SYS, &at91sam926x_pit_irq);
break;
case CLOCK_EVT_MODE_RESUME:
break;
}
}
/*
* Clocksource: just a monotonic counter of MCK/16 cycles.
* We don't care whether or not PIT irqs are enabled.
*/
static cycle_t read_pit_clk(void)
{
unsigned long flags;
u32 elapsed;
u32 t;
raw_local_irq_save(flags);
elapsed = pit_cnt;
t = at91_sys_read(AT91_PIT_PIIR);
raw_local_irq_restore(flags);
elapsed += PIT_PICNT(t) * pit_cycle;
elapsed += PIT_CPIV(t);
return elapsed;
}
/*
* Clocksource: just a monotonic counter of MCK/16 cycles.
* We don't care whether or not PIT irqs are enabled.
*/
static cycle_t read_pit_clk(struct clocksource *cs)
{
unsigned long flags;
u32 elapsed;
u32 t;
raw_local_irq_save(flags);
elapsed = pit_cnt;
t = pit_read(AT91_PIT_PIIR);
raw_local_irq_restore(flags);
elapsed += PIT_PICNT(t) * pit_cycle;
elapsed += PIT_CPIV(t);
return elapsed;
}
static void at91sam926x_pit_reset(void)
{
/* Disable timer and irqs */
at91_sys_write(AT91_PIT_MR, 0);
/* Clear any pending interrupts, wait for PIT to stop counting */
while (PIT_CPIV(at91_sys_read(AT91_PIT_PIVR)) != 0)
;
/* Start PIT but don't enable IRQ */
//at91_sys_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN);
pit_cnt += pit_cycle * PIT_PICNT(at91_sys_read(AT91_PIT_PIVR));
at91_sys_write(AT91_PIT_MR, (pit_cycle - 1) | AT91_PIT_PITEN
| AT91_PIT_PITIEN);
rt_kprintf("PIT_MR=0x%08x\n", at91_sys_read(AT91_PIT_MR));
}
/**
* This function will handle rtos timer
*/
void rt_timer_handler(int vector)
{
#ifdef USE_DBGU
if (at91_sys_read(AT91_DBGU + AT91_US_CSR) & 0x1) {
//rt_kprintf("DBGU interrupt occur\n");
rt_serial_handler(1);
}
#endif
if (at91_sys_read(AT91_PIT_SR) & AT91_PIT_PITS) {
unsigned nr_ticks;
/* Get number of ticks performed before irq, and ack it */
nr_ticks = PIT_PICNT(at91_sys_read(AT91_PIT_PIVR));
rt_tick_increase();
}
}
/*
* IRQ handler for the timer.
*/
static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id)
{
/* The PIT interrupt may be disabled, and is shared */
if ((pit_clkevt.mode == CLOCK_EVT_MODE_PERIODIC)
&& (at91_sys_read(AT91_PIT_SR) & AT91_PIT_PITS)) {
unsigned nr_ticks;
/* Get number of ticks performed before irq, and ack it */
nr_ticks = PIT_PICNT(at91_sys_read(AT91_PIT_PIVR));
do {
pit_cnt += pit_cycle;
pit_clkevt.event_handler(&pit_clkevt);
nr_ticks--;
} while (nr_ticks);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
