Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / u-boot / arch / arm / cpu / arm920t / ep93xx / timer.c

diff --git a/qemu/roms/u-boot/arch/arm/cpu/arm920t/ep93xx/timer.c b/qemu/roms/u-boot/arch/arm/cpu/arm920t/ep93xx/timer.c
new file mode 100644 (file)
index 0000000..c2f239a
--- /dev/null
+++ b/qemu/roms/u-boot/arch/arm/cpu/arm920t/ep93xx/timer.c
@@ -0,0 +1,120 @@
+/*
+ * Cirrus Logic EP93xx timer support.
+ *
+ * Copyright (C) 2009, 2010 Matthias Kaehlcke <matthias@kaehlcke.net>
+ *
+ * Copyright (C) 2004, 2005
+ * Cory T. Tusar, Videon Central, Inc., <ctusar@videon-central.com>
+ *
+ * Based on the original intr.c Cirrus Logic EP93xx Rev D. interrupt support,
+ * author unknown.
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <linux/types.h>
+#include <asm/arch/ep93xx.h>
+#include <asm/io.h>
+#include <div64.h>
+
+#define TIMER_CLKSEL   (1 << 3)
+#define TIMER_ENABLE   (1 << 7)
+
+#define TIMER_FREQ                     508469          /* ticks / second */
+#define TIMER_MAX_VAL                  0xFFFFFFFF
+
+static struct ep93xx_timer
+{
+       unsigned long long ticks;
+       unsigned long last_read;
+} timer;
+
+static inline unsigned long long usecs_to_ticks(unsigned long usecs)
+{
+       unsigned long long ticks = (unsigned long long)usecs * TIMER_FREQ;
+       do_div(ticks, 1000 * 1000);
+
+       return ticks;
+}
+
+static inline void read_timer(void)
+{
+       struct timer_regs *timer_regs = (struct timer_regs *)TIMER_BASE;
+       const unsigned long now = TIMER_MAX_VAL - readl(&timer_regs->timer3.value);
+
+       if (now >= timer.last_read)
+               timer.ticks += now - timer.last_read;
+       else
+               /* an overflow occurred */
+               timer.ticks += TIMER_MAX_VAL - timer.last_read + now;
+
+       timer.last_read = now;
+}
+
+/*
+ * Get the number of ticks (in CONFIG_SYS_HZ resolution)
+ */
+unsigned long long get_ticks(void)
+{
+       unsigned long long sys_ticks;
+
+       read_timer();
+
+       sys_ticks = timer.ticks * CONFIG_SYS_HZ;
+       do_div(sys_ticks, TIMER_FREQ);
+
+       return sys_ticks;
+}
+
+unsigned long get_timer_masked(void)
+{
+       return get_ticks();
+}
+
+unsigned long get_timer(unsigned long base)
+{
+       return get_timer_masked() - base;
+}
+
+void __udelay(unsigned long usec)
+{
+       unsigned long long target;
+
+       read_timer();
+
+       target = timer.ticks + usecs_to_ticks(usec);
+
+       while (timer.ticks < target)
+               read_timer();
+}
+
+int timer_init(void)
+{
+       struct timer_regs *timer_regs = (struct timer_regs *)TIMER_BASE;
+
+       /* use timer 3 with 508KHz and free running, not enabled now */
+       writel(TIMER_CLKSEL, &timer_regs->timer3.control);
+
+       /* set initial timer value */
+       writel(TIMER_MAX_VAL, &timer_regs->timer3.load);
+
+       /* Enable the timer */
+       writel(TIMER_ENABLE | TIMER_CLKSEL,
+               &timer_regs->timer3.control);
+
+       /* Reset the timer */
+       read_timer();
+       timer.ticks = 0;
+
+       return 0;
+}
+
+/*
+ * This function is derived from PowerPC code (timebase clock frequency).
+ * On ARM it returns the number of timer ticks per second.
+ */
+unsigned long get_tbclk(void)
+{
+       return CONFIG_SYS_HZ;
+}