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Diffstat (limited to 'arch/arm/mach-omap2/timer.c')
-rw-r--r--arch/arm/mach-omap2/timer.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
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+++ b/arch/arm/mach-omap2/timer.c
@@ -0,0 +1,103 @@
+/*
+ * (C) Copyright 2008
+ * Texas Instruments
+ *
+ * Richard Woodruff <r-woodruff2@ti.com>
+ * Syed Moahmmed Khasim <khasim@ti.com>
+ *
+ * (C) Copyright 2002
+ * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ * Alex Zuepke <azu@sysgo.de>
+ *
+ * (C) Copyright 2002
+ * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/clock.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE;
+
+/*
+ * Nothing really to do with interrupts, just starts up a counter.
+ */
+
+#define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV))
+#define TIMER_OVERFLOW_VAL 0xffffffff
+#define TIMER_LOAD_VAL 0
+
+int timer_init(void)
+{
+ /* start the counter ticking up, reload value on overflow */
+ writel(TIMER_LOAD_VAL, &timer_base->tldr);
+ /* enable timer */
+ writel((CONFIG_SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST,
+ &timer_base->tclr);
+
+ return 0;
+}
+
+/*
+ * timer without interrupts
+ */
+ulong get_timer(ulong base)
+{
+ return get_timer_masked() - base;
+}
+
+/* delay x useconds */
+void __udelay(unsigned long usec)
+{
+ long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
+ unsigned long now, last = readl(&timer_base->tcrr);
+
+ while (tmo > 0) {
+ now = readl(&timer_base->tcrr);
+ if (last > now) /* count up timer overflow */
+ tmo -= TIMER_OVERFLOW_VAL - last + now + 1;
+ else
+ tmo -= now - last;
+ last = now;
+ }
+}
+
+ulong get_timer_masked(void)
+{
+ /* current tick value */
+ ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
+
+ if (now >= gd->arch.lastinc) { /* normal mode (non roll) */
+ /* move stamp fordward with absoulte diff ticks */
+ gd->arch.tbl += (now - gd->arch.lastinc);
+ } else { /* we have rollover of incrementer */
+ gd->arch.tbl += ((TIMER_OVERFLOW_VAL / (TIMER_CLOCK /
+ CONFIG_SYS_HZ)) - gd->arch.lastinc) + now;
+ }
+ gd->arch.lastinc = now;
+ return gd->arch.tbl;
+}
+
+/*
+ * 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;
+}