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Diffstat (limited to 'arch/arm/cpu/arm926ejs/mb86r0x/timer.c')
-rw-r--r--arch/arm/cpu/arm926ejs/mb86r0x/timer.c142
1 files changed, 142 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm926ejs/mb86r0x/timer.c b/arch/arm/cpu/arm926ejs/mb86r0x/timer.c
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index 0000000..9175b71
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+++ b/arch/arm/cpu/arm926ejs/mb86r0x/timer.c
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+/*
+ * (C) Copyright 2007-2008
+ * Stelian Pop <stelian.pop@leadtechdesign.com>
+ * Lead Tech Design <www.leadtechdesign.com>
+ *
+ * (C) Copyright 2010
+ * Matthias Weisser, Graf-Syteco <weisserm@arcor.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 <div64.h>
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/hardware.h>
+
+#define TIMER_LOAD_VAL 0xffffffff
+#define TIMER_FREQ (CONFIG_MB86R0x_IOCLK / 256)
+
+static unsigned long long timestamp;
+static ulong lastdec;
+
+static inline unsigned long long tick_to_time(unsigned long long tick)
+{
+ tick *= CONFIG_SYS_HZ;
+ do_div(tick, TIMER_FREQ);
+
+ return tick;
+}
+
+static inline unsigned long long usec_to_tick(unsigned long long usec)
+{
+ usec *= TIMER_FREQ;
+ do_div(usec, 1000000);
+
+ return usec;
+}
+
+/* nothing really to do with interrupts, just starts up a counter. */
+int timer_init(void)
+{
+ struct mb86r0x_timer * timer = (struct mb86r0x_timer *)
+ MB86R0x_TIMER_BASE;
+ ulong ctrl = readl(&timer->control);
+
+ writel(TIMER_LOAD_VAL, &timer->load);
+
+ ctrl |= MB86R0x_TIMER_ENABLE | MB86R0x_TIMER_PRS_8S |
+ MB86R0x_TIMER_SIZE_32;
+
+ writel(ctrl, &timer->control);
+
+ reset_timer_masked();
+
+ return 0;
+}
+
+/*
+ * timer without interrupts
+ */
+unsigned long long get_ticks(void)
+{
+ struct mb86r0x_timer * timer = (struct mb86r0x_timer *)
+ MB86R0x_TIMER_BASE;
+ ulong now = readl(&timer->value);
+
+ if (now <= lastdec) {
+ /* normal mode (non roll) */
+ /* move stamp forward with absolut diff ticks */
+ timestamp += lastdec - now;
+ } else {
+ /* we have rollover of incrementer */
+ timestamp += lastdec + TIMER_LOAD_VAL - now;
+ }
+ lastdec = now;
+ return timestamp;
+}
+
+void reset_timer_masked(void)
+{
+ struct mb86r0x_timer * timer = (struct mb86r0x_timer *)
+ MB86R0x_TIMER_BASE;
+
+ /* capture current value time */
+ lastdec = readl(&timer->value);
+ timestamp = 0; /* start "advancing" time stamp from 0 */
+}
+
+ulong get_timer_masked(void)
+{
+ return tick_to_time(get_ticks());
+}
+
+void __udelay(unsigned long usec)
+{
+ unsigned long long tmp;
+ ulong tmo;
+
+ tmo = usec_to_tick(usec);
+ tmp = get_ticks(); /* get current timestamp */
+
+ while ((get_ticks() - tmp) < tmo) /* loop till event */
+ /*NOP*/;
+}
+
+void reset_timer(void)
+{
+ reset_timer_masked();
+}
+
+ulong get_timer(ulong base)
+{
+ return get_timer_masked() - base;
+}
+
+/*
+ * 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_FREQ;
+ return tbclk;
+}