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-rw-r--r--arch/arm/cpu/arm925t/timer.c137
1 files changed, 137 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm925t/timer.c b/arch/arm/cpu/arm925t/timer.c
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+++ b/arch/arm/cpu/arm925t/timer.c
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+/*
+ * (C) Copyright 2009
+ * 2N Telekomunikace, <www.2n.cz>
+ *
+ * (C) Copyright 2003
+ * Texas Instruments, <www.ti.com>
+ *
+ * (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 <arm925t.h>
+#include <configs/omap1510.h>
+#include <asm/io.h>
+
+#define TIMER_LOAD_VAL 0xffffffff
+#define TIMER_CLOCK (CONFIG_SYS_CLK_FREQ / (2 << CONFIG_SYS_PTV))
+
+static uint32_t timestamp;
+static uint32_t lastdec;
+
+/* nothing really to do with interrupts, just starts up a counter. */
+int timer_init (void)
+{
+ /* Start the decrementer ticking down from 0xffffffff */
+ __raw_writel(TIMER_LOAD_VAL, CONFIG_SYS_TIMERBASE + LOAD_TIM);
+ __raw_writel(MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE |
+ (CONFIG_SYS_PTV << MPUTIM_PTV_BIT),
+ CONFIG_SYS_TIMERBASE + CNTL_TIMER);
+
+ /* init the timestamp and lastdec value */
+ reset_timer_masked();
+
+ 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;
+}
+
+/* delay x useconds AND preserve advance timestamp value */
+void __udelay (unsigned long usec)
+{
+ int32_t tmo = usec * (TIMER_CLOCK / 1000) / 1000;
+ uint32_t now, last = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
+
+ while (tmo > 0) {
+ now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
+ if (last < now) /* count down timer underflow */
+ tmo -= TIMER_LOAD_VAL - now + last;
+ else
+ tmo -= last - now;
+ last = now;
+ }
+}
+
+void reset_timer_masked (void)
+{
+ /* reset time */
+ lastdec = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM) /
+ (TIMER_CLOCK / CONFIG_SYS_HZ);
+ timestamp = 0; /* start "advancing" time stamp from 0 */
+}
+
+ulong get_timer_masked (void)
+{
+ uint32_t now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM) /
+ (TIMER_CLOCK / CONFIG_SYS_HZ);
+ if (lastdec < now) /* count down timer underflow */
+ timestamp += TIMER_LOAD_VAL / (TIMER_CLOCK / CONFIG_SYS_HZ) -
+ now + lastdec;
+ else
+ timestamp += lastdec - now;
+ lastdec = now;
+
+ return timestamp;
+}
+
+/*
+ * 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)
+{
+ return CONFIG_SYS_HZ;
+}