void
cpu_initclocks(void)
{
struct s3c24x0_softc *sc = (struct s3c24x0_softc *)s3c2xx0_softc;
long tc;
struct resource *irq;
int rid = 0;
void *ihl;
int err, prescaler;
int pclk = s3c2xx0_softc->sc_pclk;
bus_space_tag_t iot = sc->sc_sx.sc_iot;
bus_space_handle_t ioh = sc->sc_timer_ioh;
uint32_t reg;
device_t dev = timer_softc.dev;
/* We have already been initialized */
if (timer4_reload_value != 0)
return;
#define time_constant(hz) (TIMER_FREQUENCY(pclk) /(hz)/ prescaler)
#define calc_time_constant(hz) \
do { \
prescaler = 1; \
do { \
++prescaler; \
tc = time_constant(hz); \
} while( tc > 65536 ); \
} while(0)
/* Use the channels 4 and 3 for hardclock and statclock, respectively */
/* stop all timers */
bus_space_write_4(iot, ioh, TIMER_TCON, 0);
/* calc suitable prescaler value */
calc_time_constant(hz);
timer4_prescaler = prescaler;
timer4_reload_value = TIMER_FREQUENCY(pclk) / hz / prescaler;
timer4_mseccount = TIMER_FREQUENCY(pclk)/timer4_prescaler/1000 ;
bus_space_write_4(iot, ioh, TIMER_TCNTB(4),
((prescaler - 1) << 16) | (timer4_reload_value - 1));
printf("clock: hz=%d PCLK=%d prescaler=%d tc=%ld\n",
hz, pclk, prescaler, tc);
irq = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, S3C24X0_INT_TIMER4,
S3C24X0_INT_TIMER4, 1, RF_ACTIVE);
if (!irq)
panic("Unable to allocate the clock irq handler.\n");
err = bus_setup_intr(dev, irq, INTR_TYPE_CLK,
clock_intr, NULL, NULL, &ihl);
if (err != 0)
panic("Unable to setup the clock irq handler.\n");
/* set prescaler1 */
reg = bus_space_read_4(iot, ioh, TIMER_TCFG0);
bus_space_write_4(iot, ioh, TIMER_TCFG0,
(reg & ~0xff00) | ((prescaler-1) << 8));
/* divider 1/16 for ch #4 */
reg = bus_space_read_4(iot, ioh, TIMER_TCFG1);
bus_space_write_4(iot, ioh, TIMER_TCFG1,
(reg & ~(TCFG1_MUX_MASK(4))) |
(TCFG1_MUX_DIV16 << TCFG1_MUX_SHIFT(4)) );
/* start timers */
reg = bus_space_read_4(iot, ioh, TIMER_TCON);
reg &= ~(TCON_MASK(4));
/* load the time constant */
bus_space_write_4(iot, ioh, TIMER_TCON, reg | TCON_MANUALUPDATE(4));
/* set auto reload and start */
bus_space_write_4(iot, ioh, TIMER_TCON, reg |
TCON_AUTORELOAD(4) | TCON_START(4) );
s3c24x0_timer_timecounter.tc_frequency = TIMER_FREQUENCY(pclk) /
timer4_prescaler;
tc_init(&s3c24x0_timer_timecounter);
}
void s5p6818_timer_count(virtual_addr_t virt, int ch, u32_t cnt)
{
write32(virt + TIMER_TCNTB(ch), cnt);
write32(virt + TIMER_TCMPB(ch), cnt);
}