[src/trunk]: src/sys/arch/arm/s3c2xx0 - use a correct bit mask to pick SRCPND...

[nisimura <nisimura%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/81978319ceb4
branches:  trunk
changeset: 773627:81978319ceb4
user:      nisimura <nisimura%NetBSD.org@localhost>
date:      Fri Feb 10 09:17:49 2012 +0000

description:
- use a correct bit mask to pick SRCPND register indication.
- reading timer#4 possibly returns value '0'.  Having the
  '0' and a timer reload interrupt results in a too large
  number, meaning the next get_timecounter() call will
  return a smaller one than the previous, effectively kill
  things.  Handle this case.

ping(8) now shows better precisions.  Fixes from Paul Fleischer.

Ok by releng.

diffstat:

 sys/arch/arm/s3c2xx0/s3c24x0_clk.c |  28 ++++++++++++++--------------
 1 files changed, 14 insertions(+), 14 deletions(-)

diffs (90 lines):

diff -r 18a488b2ecf4 -r 81978319ceb4 sys/arch/arm/s3c2xx0/s3c24x0_clk.c
--- a/sys/arch/arm/s3c2xx0/s3c24x0_clk.c        Fri Feb 10 06:28:39 2012 +0000
+++ b/sys/arch/arm/s3c2xx0/s3c24x0_clk.c        Fri Feb 10 09:17:49 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: s3c24x0_clk.c,v 1.13 2012/02/07 09:06:05 nisimura Exp $ */
+/*     $NetBSD: s3c24x0_clk.c,v 1.14 2012/02/10 09:17:49 nisimura Exp $ */
 
 /*
  * Copyright (c) 2003  Genetec corporation.  All rights reserved.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: s3c24x0_clk.c,v 1.13 2012/02/07 09:06:05 nisimura Exp $");
+__KERNEL_RCSID(0, "$NetBSD: s3c24x0_clk.c,v 1.14 2012/02/10 09:17:49 nisimura Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -53,9 +53,9 @@
 
 #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;
+static uint32_t timer4_reload_value;
+static uint32_t timer4_prescaler;
+static uint32_t timer4_mseccount;
 
 #define usec_to_counter(t)     \
        ((timer4_mseccount*(t))/1000)
@@ -68,7 +68,7 @@
 static struct timecounter s3c24x0_timecounter = {
        s3c24x0_get_timecount,  /* get_timecount */
        0,                      /* no poll_pps */
-       0xfff,                  /* counter_mask */
+       0xffffffff,             /* counter_mask */
        0,                      /* frequency */
        "s3c24x0",              /* name */
        100,                    /* quality */
@@ -83,21 +83,22 @@
 {
        struct s3c24x0_softc *sc = (struct s3c24x0_softc *) s3c2xx0_softc;
        int save, int_pend0, int_pend1, count;
+       int int_pend;
 
        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,
+       int_pend = bus_space_read_4(sc->sc_sx.sc_iot, sc->sc_sx.sc_intctl_ioh,
                INTCTL_SRCPND);
+       int_pend0 = (1<<S3C24X0_INT_TIMER4) & int_pend;
        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);
+               int_pend1 = bus_space_read_4(sc->sc_sx.sc_iot,
+                       sc->sc_sx.sc_intctl_ioh, INTCTL_SRCPND);
+               int_pend1 &= (1<<S3C24X0_INT_TIMER4);
                if( int_pend0 == int_pend1 )
                        break;
 
@@ -122,11 +123,10 @@
 
        restore_interrupts(save);
 
-       if (int_pend1) {
+       if (int_pend1 && count > 0) {
                count -= timer4_reload_value;
        }
 
-       //printf("delta: %u\n", (s3c24x0_base - count));
        return s3c24x0_base - count;
 }
 
@@ -250,7 +250,7 @@
        calc_time_constant(h);
 
        timer4_prescaler = prescaler;
-       timer4_reload_value = TIMER_FREQUENCY(pclk) / hz / prescaler;
+       timer4_reload_value = (TIMER_FREQUENCY(pclk) / hz / prescaler) - 1;
        timer4_mseccount = TIMER_FREQUENCY(pclk)/timer4_prescaler/1000 ;
 
        bus_space_write_4(iot, ioh, TIMER_TCNTB(4),