i.MX31: Add reset_timer() and modify get_timer_masked().

[platform/kernel/u-boot.git] / cpu / arm1136 / mx31 / interrupts.c

diff --git a/cpu/arm1136/mx31/interrupts.c b/cpu/arm1136/mx31/interrupts.c
index 189f601..6e08c71 100644 (file)
--- a/cpu/arm1136/mx31/interrupts.c
+++ b/cpu/arm1136/mx31/interrupts.c
@@ -38,76 +38,81 @@
 #define GPTCR_CLKSOURCE_32 (4<<6)  /* Clock source */
 #define GPTCR_TEN       (1)     /* Timer enable */
 
-/*
- * nothing really to do with interrupts, just starts up a counter.
- */
-int interrupt_init(void)
+static ulong timestamp;
+static ulong lastinc;
+
+/* nothing really to do with interrupts, just starts up a counter. */
+int interrupt_init (void)
 {
        int i;
 
        /* setup GP Timer 1 */
        GPTCR = GPTCR_SWR;
-       for (i = 0; i < 100; i++) GPTCR = 0; /* We have no udelay by now */
+       for ( i=0; i<100; i++) GPTCR = 0; /* We have no udelay by now */
        GPTPR = 0; /* 32Khz */
-       /* Freerun Mode, PERCLK1 input */
-       GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN;
+       GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN; /* Freerun Mode, PERCLK1 input */
 
        return 0;
 }
 
-void reset_timer_masked(void)
+void reset_timer_masked (void)
 {
-       GPTCR = 0;
-       /* Freerun Mode, PERCLK1 input*/
-       GPTCR = GPTCR_CLKSOURCE_32 | GPTCR_TEN;
+       /* reset time */
+       lastinc = GPTCNT; /* capture current incrementer value time */
+       timestamp = 0; /* start "advancing" time stamp from 0 */
 }
 
-ulong get_timer_masked(void)
+void reset_timer(void)
 {
-       ulong val = GPTCNT;
-       return val;
+       reset_timer_masked();
+}
+
+ulong get_timer_masked (void)
+{
+       ulong now = GPTCNT; /* current tick value */
+
+       if (now >= lastinc)     /* normal mode (non roll) */
+               /* move stamp forward with absolut diff ticks */
+               timestamp += (now - lastinc);
+       else                    /* we have rollover of incrementer */
+               timestamp += (0xFFFFFFFF - lastinc) + now;
+       lastinc = now;
+       return timestamp;
 }
 
-ulong get_timer(ulong base)
+ulong get_timer (ulong base)
 {
-       return get_timer_masked() - base;
+       return get_timer_masked () - base;
 }
 
-void set_timer(ulong t)
+void set_timer (ulong t)
 {
 }
 
 /* delay x useconds AND perserve advance timstamp value */
-void udelay(unsigned long usec)
+void udelay (unsigned long usec)
 {
        ulong tmo, tmp;
 
-       if (usec >= 1000) {
-       /* "big" number, spread normalization to seconds */
-               /* start to normalize for usec to ticks per sec */
-               tmo = usec / 1000;
-               /* find number of "ticks" to wait to achieve target */
-               tmo *= CFG_HZ;
-               tmo /= 1000;    /* finish normalize. */
-       } else {
-               /* else small number, don't kill it prior to HZ multiply */
+       if (usec >= 1000) {                     /* if "big" number, spread normalization to seconds */
+               tmo = usec / 1000;              /* start to normalize for usec to ticks per sec */
+               tmo *= CFG_HZ;                  /* find number of "ticks" to wait to achieve target */
+               tmo /= 1000;                    /* finish normalize. */
+       } else {                                        /* else small number, don't kill it prior to HZ multiply */
                tmo = usec * CFG_HZ;
                tmo /= (1000*1000);
        }
 
-       tmp = get_timer(0);             /* get current timestamp */
-       if ((tmo + tmp + 1) < tmp)
-               /* setting this forward will roll time stamp */
-               /* reset "advancing" timestamp to 0, set lastinc value */
-               reset_timer_masked();
+       tmp = get_timer (0);            /* get current timestamp */
+       if ( (tmo + tmp + 1) < tmp )/* if setting this forward will roll time stamp */
+               reset_timer_masked ();  /* reset "advancing" timestamp to 0, set lastinc value */
        else
-               /* else, set advancing stamp wake up time */
-               tmo     += tmp;
-       while (get_timer_masked() < tmo)/* loop till event */
+               tmo     += tmp;                         /* else, set advancing stamp wake up time */
+       while (get_timer_masked () < tmo)/* loop till event */
                /*NOP*/;
 }
 
-void reset_cpu(ulong addr)
+void reset_cpu (ulong addr)
 {
        __REG16(WDOG_BASE) = 4;
 }