summaryrefslogtreecommitdiff
path: root/arch/arm/cpu/s3c44b0/timer.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/cpu/s3c44b0/timer.c')
-rw-r--r--arch/arm/cpu/s3c44b0/timer.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/arch/arm/cpu/s3c44b0/timer.c b/arch/arm/cpu/s3c44b0/timer.c
new file mode 100644
index 0000000..6f1d8f6
--- /dev/null
+++ b/arch/arm/cpu/s3c44b0/timer.c
@@ -0,0 +1,136 @@
+/*
+ * (C) Copyright 2004
+ * DAVE Srl
+ * http://www.dave-tech.it
+ * http://www.wawnet.biz
+ * mailto:info@wawnet.biz
+ *
+ * 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 <asm/hardware.h>
+
+/* we always count down the max. */
+#define TIMER_LOAD_VAL 0xffff
+
+/* macro to read the 16 bit timer */
+#define READ_TIMER (TCNTO1 & 0xffff)
+
+#ifdef CONFIG_USE_IRQ
+#error CONFIG_USE_IRQ NOT supported
+#endif
+
+static ulong timestamp;
+static ulong lastdec;
+
+int timer_init (void)
+{
+ TCFG0 = 0x000000E9;
+ TCFG1 = 0x00000004;
+ TCON = 0x00000900;
+ TCNTB1 = TIMER_LOAD_VAL;
+ TCMPB1 = 0;
+ TCON = 0x00000B00;
+ TCON = 0x00000900;
+
+
+ lastdec = TCNTB1 = TIMER_LOAD_VAL;
+ 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;
+
+ tmo = usec / 1000;
+ tmo *= CONFIG_SYS_HZ;
+ tmo /= 8;
+
+ tmo += get_timer (0);
+
+ while (get_timer_masked () < tmo)
+ /*NOP*/;
+}
+
+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;
+
+ if (usec >= 1000) {
+ tmo = usec / 1000;
+ tmo *= CONFIG_SYS_HZ;
+ tmo /= 8;
+ } else {
+ tmo = usec * CONFIG_SYS_HZ;
+ tmo /= (1000*8);
+ }
+
+ endtime = get_timer(0) + tmo;
+
+ do {
+ ulong now = get_timer_masked ();
+ diff = endtime - now;
+ } while (diff >= 0);
+}