summaryrefslogtreecommitdiff
path: root/board/armltd/integrator/timer.c
diff options
context:
space:
mode:
Diffstat (limited to 'board/armltd/integrator/timer.c')
-rw-r--r--board/armltd/integrator/timer.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/board/armltd/integrator/timer.c b/board/armltd/integrator/timer.c
new file mode 100644
index 0000000000..087cf59622
--- /dev/null
+++ b/board/armltd/integrator/timer.c
@@ -0,0 +1,200 @@
+/*
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * David Mueller, ELSOFT AG, <d.mueller@elsoft.ch>
+ *
+ * (C) Copyright 2003
+ * Texas Instruments, <www.ti.com>
+ * Kshitij Gupta <Kshitij@ti.com>
+ *
+ * (C) Copyright 2004
+ * ARM Ltd.
+ * Philippe Robin, <philippe.robin@arm.com>
+ *
+ * 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 <div64.h>
+
+#ifdef CONFIG_ARCH_CINTEGRATOR
+#define DIV_CLOCK_INIT 1
+#define TIMER_LOAD_VAL 0xFFFFFFFFL
+#else
+#define DIV_CLOCK_INIT 256
+#define TIMER_LOAD_VAL 0x0000FFFFL
+#endif
+/* The Integrator/CP timer1 is clocked at 1MHz
+ * can be divided by 16 or 256
+ * and can be set up as a 32-bit timer
+ */
+/* U-Boot expects a 32 bit timer, running at CONFIG_SYS_HZ */
+/* Keep total timer count to avoid losing decrements < div_timer */
+static unsigned long long total_count = 0;
+static unsigned long long lastdec; /* Timer reading at last call */
+/* Divisor applied to timer clock */
+static unsigned long long div_clock = DIV_CLOCK_INIT;
+static unsigned long long div_timer = 1; /* Divisor to convert timer reading
+ * change to U-Boot ticks
+ */
+/* CONFIG_SYS_HZ = CONFIG_SYS_HZ_CLOCK/(div_clock * div_timer) */
+static ulong timestamp; /* U-Boot ticks since startup */
+
+#define READ_TIMER (*(volatile ulong *)(CONFIG_SYS_TIMERBASE+4))
+
+/* all function return values in U-Boot ticks i.e. (1/CONFIG_SYS_HZ) sec
+ * - unless otherwise stated
+ */
+
+/* starts up a counter
+ * - the Integrator/CP timer can be set up to issue an interrupt */
+int timer_init (void)
+{
+ /* Load timer with initial value */
+ *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 0) = TIMER_LOAD_VAL;
+#ifdef CONFIG_ARCH_CINTEGRATOR
+ /* Set timer to be
+ * enabled 1
+ * periodic 1
+ * no interrupts 0
+ * X 0
+ * divider 1 00 == less rounding error
+ * 32 bit 1
+ * wrapping 0
+ */
+ *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8) = 0x000000C2;
+#else
+ /* Set timer to be
+ * enabled 1
+ * free-running 0
+ * XX 00
+ * divider 256 10
+ * XX 00
+ */
+ *(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8) = 0x00000088;
+#endif
+
+ /* init the timestamp */
+ total_count = 0ULL;
+ reset_timer_masked();
+
+ div_timer = CONFIG_SYS_HZ_CLOCK;
+ do_div(div_timer, CONFIG_SYS_HZ);
+ do_div(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;
+}
+
+/* delay usec useconds */
+void udelay (unsigned long usec)
+{
+ ulong tmo, tmp;
+
+ /* Convert to U-Boot ticks */
+ tmo = usec * CONFIG_SYS_HZ;
+ tmo /= (1000000L);
+
+ tmp = get_timer_masked(); /* get current timestamp */
+ tmo += tmp; /* form target timestamp */
+
+ while (get_timer_masked () < tmo) {/* loop till event */
+ /*NOP*/;
+ }
+}
+
+void reset_timer_masked (void)
+{
+ /* capure current decrementer value */
+ lastdec = READ_TIMER;
+ /* start "advancing" time stamp from 0 */
+ timestamp = 0L;
+}
+
+/* converts the timer reading to U-Boot ticks */
+/* the timestamp is the number of ticks since reset */
+ulong get_timer_masked (void)
+{
+ /* get current count */
+ unsigned long long now = READ_TIMER;
+
+ if(now > lastdec) {
+ /* Must have wrapped */
+ total_count += lastdec + TIMER_LOAD_VAL + 1 - now;
+ } else {
+ total_count += lastdec - now;
+ }
+ lastdec = now;
+
+ /* Reuse "now" */
+ now = total_count;
+ do_div(now, div_timer);
+ timestamp = now;
+
+ 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)
+{
+ unsigned long long tmp = CONFIG_SYS_HZ_CLOCK;
+
+ do_div(tmp, div_clock);
+
+ return tmp;
+}