summaryrefslogtreecommitdiff
path: root/board/integratorap/integratorap.c
diff options
context:
space:
mode:
Diffstat (limited to 'board/integratorap/integratorap.c')
-rw-r--r--board/integratorap/integratorap.c137
1 files changed, 137 insertions, 0 deletions
diff --git a/board/integratorap/integratorap.c b/board/integratorap/integratorap.c
index fb83c82..6140a7a 100644
--- a/board/integratorap/integratorap.c
+++ b/board/integratorap/integratorap.c
@@ -477,3 +477,140 @@ int dram_init (void)
{
return 0;
}
+
+/* The Integrator/AP timer1 is clocked at 24MHz
+ * can be divided by 16 or 256
+ * and is a 16-bit counter
+ */
+/* U-Boot expects a 32 bit timer running at CFG_HZ*/
+static ulong timestamp; /* U-Boot ticks since startup */
+static ulong total_count = 0; /* Total timer count */
+static ulong lastdec; /* Timer reading at last call */
+static ulong div_clock = 256; /* Divisor applied to the timer clock */
+static ulong div_timer = 1; /* Divisor to convert timer reading
+ * change to U-Boot ticks
+ */
+/* CFG_HZ = CFG_HZ_CLOCK/(div_clock * div_timer) */
+
+#define TIMER_LOAD_VAL 0x0000FFFFL
+#define READ_TIMER ((*(volatile ulong *)(CFG_TIMERBASE+4)) & 0x0000FFFFL)
+
+/* all function return values in U-Boot ticks i.e. (1/CFG_HZ) sec
+ * - unless otherwise stated
+ */
+
+/* starts a counter
+ * - the Integrator/AP timer issues an interrupt
+ * each time it reaches zero
+ */
+int interrupt_init (void)
+{
+ /* Load timer with initial value */
+ *(volatile ulong *)(CFG_TIMERBASE + 0) = TIMER_LOAD_VAL;
+ /* Set timer to be
+ * enabled 1
+ * free-running 0
+ * XX 00
+ * divider 256 10
+ * XX 00
+ */
+ *(volatile ulong *)(CFG_TIMERBASE + 8) = 0x00000088;
+ total_count = 0;
+ /* init the timestamp and lastdec value */
+ reset_timer_masked();
+
+ div_timer = CFG_HZ_CLOCK / CFG_HZ;
+ div_timer /= div_clock;
+
+ return (0);
+}
+
+/*
+ * timer without interrupts
+ */
+void reset_timer (void)
+{
+ reset_timer_masked ();
+}
+
+ulong get_timer (ulong base_ticks)
+{
+ return get_timer_masked () - base_ticks;
+}
+
+void set_timer (ulong ticks)
+{
+ timestamp = ticks;
+ total_count = ticks * div_timer;
+ reset_timer_masked();
+}
+
+/* delay x useconds */
+void udelay (unsigned long usec)
+{
+ ulong tmo, tmp;
+
+ /* Convert to U-Boot ticks */
+ tmo = usec * CFG_HZ;
+ tmo /= (1000000L);
+
+ tmp = get_timer_masked(); /* get current timestamp */
+ tmo += tmp; /* wake up timestamp */
+
+ while (get_timer_masked () < tmo)/* loop till event */
+ {
+ /*NOP*/;
+ }
+}
+
+void reset_timer_masked (void)
+{
+ /* reset time */
+ lastdec = READ_TIMER; /* capture current decrementer value */
+ timestamp = 0; /* start "advancing" time stamp from 0 */
+}
+
+/* converts the timer reading to U-Boot ticks */
+/* the timestamp is the number of ticks since reset */
+/* This routine does not detect wraps unless called regularly
+ ASSUMES a call at least every 16 seconds to detect every reload */
+ulong get_timer_masked (void)
+{
+ ulong now = READ_TIMER; /* current count */
+
+ if(now > lastdec)
+ {
+ /* Must have wrapped */
+ total_count += lastdec + TIMER_LOAD_VAL + 1 - now;
+ } else {
+ total_count += lastdec - now;
+ }
+ lastdec = now;
+ timestamp = total_count/div_timer;
+
+ return timestamp;
+}
+
+/* waits specified delay value and resets timestamp */
+void udelay_masked (unsigned long usec)
+{
+ udelay(usec);
+}
+
+/*
+ * This function is derived from PowerPC code (read timebase as long long).
+ * On ARM it just returns the timer value.
+ */
+unsigned long long get_ticks(void)
+{
+ return get_timer(0);
+}
+
+/*
+ * Return the timebase clock frequency
+ * i.e. how often the timer decrements
+ */
+ulong get_tbclk (void)
+{
+ return CFG_HZ_CLOCK/div_clock;
+}