NetBSD/sys/arch/arm/s3c2xx0/s3c24x0_clk.c

370 lines
8.7 KiB
C

/* $NetBSD: s3c24x0_clk.c,v 1.6 2005/12/24 20:06:52 perry Exp $ */
/*
* Copyright (c) 2003 Genetec corporation. All rights reserved.
* Written by Hiroyuki Bessho for Genetec corporation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of Genetec corporation may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY GENETEC CORP. ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GENETEC CORP.
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: s3c24x0_clk.c,v 1.6 2005/12/24 20:06:52 perry Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/time.h>
#include <machine/bus.h>
#include <machine/intr.h>
#include <arm/cpufunc.h>
#include <arm/s3c2xx0/s3c24x0reg.h>
#include <arm/s3c2xx0/s3c24x0var.h>
#ifndef STATHZ
#define STATHZ 64
#endif
#define TIMER_FREQUENCY(pclk) ((pclk)/16) /* divider=1/16 */
static unsigned int timer4_reload_value;
static unsigned int timer4_prescaler;
static unsigned int timer4_mseccount;
#define usec_to_counter(t) \
((timer4_mseccount*(t))/1000)
#define counter_to_usec(c,pclk) \
(((c)*timer4_prescaler*1000)/(TIMER_FREQUENCY(pclk)/1000))
/*
* microtime:
*
* Fill in the specified timeval struct with the current time
* accurate to the microsecond.
*/
void
microtime(struct timeval *tvp)
{
struct s3c24x0_softc *sc = (struct s3c24x0_softc *) s3c2xx0_softc;
int save, int_pend0, int_pend1, count, delta;
static struct timeval last;
int pclk = s3c2xx0_softc->sc_pclk;
if( timer4_reload_value == 0 ){
/* not initialized yet */
tvp->tv_sec = 0;
tvp->tv_usec = 0;
return;
}
save = disable_interrupts(I32_bit);
again:
int_pend0 = S3C24X0_INT_TIMER4 &
bus_space_read_4(sc->sc_sx.sc_iot, sc->sc_sx.sc_intctl_ioh,
INTCTL_SRCPND);
count = bus_space_read_2(sc->sc_sx.sc_iot, sc->sc_timer_ioh,
TIMER_TCNTO(4));
for (;;){
int_pend1 = S3C24X0_INT_TIMER4 &
bus_space_read_4(sc->sc_sx.sc_iot, sc->sc_sx.sc_intctl_ioh,
INTCTL_SRCPND);
if( int_pend0 == int_pend1 )
break;
/*
* Down counter reached to zero while we were reading
* timer values. do it again to get consistent values.
*/
int_pend0 = int_pend1;
count = bus_space_read_2(sc->sc_sx.sc_iot, sc->sc_timer_ioh,
TIMER_TCNTO(4));
}
if( __predict_false(count > timer4_reload_value) ){
/*
* Buggy Hardware Warning --- sometimes timer counter
* reads bogus value like 0xffff. I guess it happens when
* the timer is reloaded.
*/
printf( "Bogus value from timer counter: %d\n", count );
goto again;
}
/* copy system time */
*tvp = time;
restore_interrupts(save);
delta = timer4_reload_value - count;
if( int_pend1 ){
/*
* down counter underflow, but
* clock interrupt have not serviced yet
*/
tvp->tv_usec += tick;
}
tvp->tv_usec += counter_to_usec(delta, pclk);
/* Make sure microseconds doesn't overflow. */
tvp->tv_sec += tvp->tv_usec / 1000000;
tvp->tv_usec = tvp->tv_usec % 1000000;
if (last.tv_sec &&
(tvp->tv_sec < last.tv_sec ||
(tvp->tv_sec == last.tv_sec &&
tvp->tv_usec < last.tv_usec) ) ){
/* XXX: This happens very often when the kernel runs
under Multi-ICE */
#if 0
printf("time reversal: %ld.%06ld(%d,%d) -> %ld.%06ld(%d,%d)\n",
last.tv_sec, last.tv_usec,
last_count, last_pend,
tvp->tv_sec, tvp->tv_usec,
count, int_pend1 );
#endif
/* make sure the time has advanced. */
*tvp = last;
tvp->tv_usec++;
if( tvp->tv_usec >= 1000000 ){
tvp->tv_usec -= 1000000;
tvp->tv_sec++;
}
}
last = *tvp;
}
static inline int
read_timer(struct s3c24x0_softc *sc)
{
int count;
do {
count = bus_space_read_2(sc->sc_sx.sc_iot, sc->sc_timer_ioh,
TIMER_TCNTO(4));
} while ( __predict_false(count > timer4_reload_value) );
return count;
}
/*
* delay:
*
* Delay for at least N microseconds.
*/
void
delay(u_int n)
{
struct s3c24x0_softc *sc = (struct s3c24x0_softc *) s3c2xx0_softc;
int v0, v1, delta;
u_int ucnt;
if ( timer4_reload_value == 0 ){
/* not initialized yet */
while ( n-- > 0 ){
int m;
for (m=0; m<100; ++m )
;
}
return;
}
/* read down counter */
v0 = read_timer(sc);
ucnt = usec_to_counter(n);
while( ucnt > 0 ) {
v1 = read_timer(sc);
delta = v0 - v1;
if ( delta < 0 )
delta += timer4_reload_value;
#ifdef DEBUG
if (delta < 0 || delta > timer4_reload_value)
panic("wrong value from timer counter");
#endif
if((u_int)delta < ucnt){
ucnt -= (u_int)delta;
v0 = v1;
}
else {
ucnt = 0;
}
}
/*NOTREACHED*/
}
/*
* inittodr:
*
* Initialize time from the time-of-day register.
*/
void
inittodr(time_t base)
{
time.tv_sec = base;
time.tv_usec = 0;
}
/*
* resettodr:
*
* Reset the time-of-day register with the current time.
*/
void
resettodr(void)
{
}
void
setstatclockrate(int newhz)
{
}
#define hardintr (int (*)(void *))hardclock
#define statintr (int (*)(void *))statclock
void
cpu_initclocks(void)
{
struct s3c24x0_softc *sc = (struct s3c24x0_softc *)s3c2xx0_softc;
long tc;
int prescaler, h;
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;
stathz = STATHZ;
profhz = stathz;
#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 */
h = MIN(hz,stathz);
calc_time_constant(h);
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 stathz = %d PCLK=%d prescaler=%d tc=%ld\n",
hz, stathz, pclk, prescaler, tc);
bus_space_write_4(iot, ioh, TIMER_TCNTB(3),
((prescaler - 1) << 16) | (time_constant(stathz) - 1));
s3c24x0_intr_establish(S3C24X0_INT_TIMER4, IPL_CLOCK,
IST_NONE, hardintr, 0);
s3c24x0_intr_establish(S3C24X0_INT_TIMER3, IPL_STATCLOCK,
IST_NONE, statintr, 0);
/* 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 #3 and #4 */
reg = bus_space_read_4(iot, ioh, TIMER_TCFG1);
bus_space_write_4(iot, ioh, TIMER_TCFG1,
(reg & ~(TCFG1_MUX_MASK(3)|TCFG1_MUX_MASK(4))) |
(TCFG1_MUX_DIV16 << TCFG1_MUX_SHIFT(3)) |
(TCFG1_MUX_DIV16 << TCFG1_MUX_SHIFT(4)) );
/* start timers */
reg = bus_space_read_4(iot, ioh, TIMER_TCON);
reg &= ~(TCON_MASK(3)|TCON_MASK(4));
/* load the time constant */
bus_space_write_4(iot, ioh, TIMER_TCON, reg |
TCON_MANUALUPDATE(3) | TCON_MANUALUPDATE(4));
/* set auto reload and start */
bus_space_write_4(iot, ioh, TIMER_TCON, reg |
TCON_AUTORELOAD(3) | TCON_START(3) |
TCON_AUTORELOAD(4) | TCON_START(4) );
}
#if 0
/* test routine for delay() */
void delay_test(void);
void
delay_test(void)
{
struct s3c2xx0_softc *sc = s3c2xx0_softc;
volatile int *pdatc = (volatile int *)
((char *)bus_space_vaddr(sc->sc_iot, sc->sc_gpio_ioh) + GPIO_PDATC);
static const int d[] = {0, 1, 5, 10, 50, 100, 500, 1000, -1};
int i;
int v = *pdatc & ~0x07;
for (;;) {
*pdatc = v | 2;
for (i=0; d[i] >= 0; ++i) {
*pdatc = v | 3;
delay(d[i]);
*pdatc = v | 2;
}
*pdatc = v;
}
}
#endif