summaryrefslogtreecommitdiff
path: root/cpu/lh7a40x/timer.c
diff options
context:
space:
mode:
Diffstat (limited to 'cpu/lh7a40x/timer.c')
-rw-r--r--cpu/lh7a40x/timer.c194
1 files changed, 194 insertions, 0 deletions
diff --git a/cpu/lh7a40x/timer.c b/cpu/lh7a40x/timer.c
new file mode 100644
index 0000000..f0baf14
--- /dev/null
+++ b/cpu/lh7a40x/timer.c
@@ -0,0 +1,194 @@
+/*
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Alex Zuepke <azu@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <arm920t.h>
+#include <lh7a40x.h>
+
+static ulong timer_load_val = 0;
+
+/* macro to read the 16 bit timer */
+static inline ulong READ_TIMER(void)
+{
+ lh7a40x_timers_t* timers = LH7A40X_TIMERS_PTR;
+ lh7a40x_timer_t* timer = &timers->timer1;
+
+ return (timer->value & 0x0000ffff);
+}
+
+static ulong timestamp;
+static ulong lastdec;
+
+int timer_init (void)
+{
+ lh7a40x_timers_t* timers = LH7A40X_TIMERS_PTR;
+ lh7a40x_timer_t* timer = &timers->timer1;
+
+ /* a periodic timer using the 508kHz source */
+ timer->control = (TIMER_PER | TIMER_CLK508K);
+
+ if (timer_load_val == 0) {
+ /*
+ * 10ms period with 508.469kHz clock = 5084
+ */
+ timer_load_val = CONFIG_SYS_HZ/100;
+ }
+
+ /* load value for 10 ms timeout */
+ lastdec = timer->load = timer_load_val;
+
+ /* auto load, start timer */
+ timer->control = timer->control | TIMER_EN;
+ timestamp = 0;
+
+ return (0);
+}
+
+/*
+ * timer without interrupts
+ */
+
+void reset_timer (void)
+{
+ reset_timer_masked ();
+}
+
+ulong get_timer (ulong base)
+{
+ return (get_timer_masked() - base);
+}
+
+void set_timer (ulong t)
+{
+ timestamp = t;
+}
+
+void udelay (unsigned long usec)
+{
+ ulong tmo,tmp;
+
+ /* normalize */
+ if (usec >= 1000) {
+ tmo = usec / 1000;
+ tmo *= CONFIG_SYS_HZ;
+ tmo /= 1000;
+ }
+ else {
+ if (usec > 1) {
+ tmo = usec * CONFIG_SYS_HZ;
+ tmo /= (1000*1000);
+ }
+ else
+ tmo = 1;
+ }
+
+ /* check for rollover during this delay */
+ tmp = get_timer (0);
+ if ((tmp + tmo) < tmp )
+ reset_timer_masked(); /* timer would roll over */
+ else
+ tmo += tmp;
+
+ while (get_timer_masked () < tmo);
+}
+
+void reset_timer_masked (void)
+{
+ /* reset time */
+ lastdec = READ_TIMER();
+ timestamp = 0;
+}
+
+ulong get_timer_masked (void)
+{
+ ulong now = READ_TIMER();
+
+ if (lastdec >= now) {
+ /* normal mode */
+ timestamp += (lastdec - now);
+ } else {
+ /* we have an overflow ... */
+ timestamp += ((lastdec + timer_load_val) - now);
+ }
+ lastdec = now;
+
+ return timestamp;
+}
+
+void udelay_masked (unsigned long usec)
+{
+ ulong tmo;
+ ulong endtime;
+ signed long diff;
+
+ /* normalize */
+ if (usec >= 1000) {
+ tmo = usec / 1000;
+ tmo *= CONFIG_SYS_HZ;
+ tmo /= 1000;
+ } else {
+ if (usec > 1) {
+ tmo = usec * CONFIG_SYS_HZ;
+ tmo /= (1000*1000);
+ } else {
+ tmo = 1;
+ }
+ }
+
+ endtime = get_timer_masked () + tmo;
+
+ do {
+ ulong now = get_timer_masked ();
+ diff = endtime - now;
+ } while (diff >= 0);
+}
+
+/*
+ * 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);
+}
+
+/*
+ * This function is derived from PowerPC code (timebase clock frequency).
+ * On ARM it returns the number of timer ticks per second.
+ */
+ulong get_tbclk (void)
+{
+ ulong tbclk;
+
+ tbclk = timer_load_val * 100;
+
+ return tbclk;
+}