Add qemu 2.4.0

[kvmfornfv.git] / qemu / roms / u-boot / arch / arm / cpu / arm926ejs / nomadik / timer.c

diff --git a/qemu/roms/u-boot/arch/arm/cpu/arm926ejs/nomadik/timer.c b/qemu/roms/u-boot/arch/arm/cpu/arm926ejs/nomadik/timer.c
new file mode 100644 (file)
index 0000000..775d0b7
--- /dev/null
+++ b/qemu/roms/u-boot/arch/arm/cpu/arm926ejs/nomadik/timer.c
@@ -0,0 +1,71 @@
+/*
+ * (C) Copyright 2009 Alessandro Rubini
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/mtu.h>
+
+/*
+ * The timer is a decrementer, we'll left it free running at 2.4MHz.
+ * We have 2.4 ticks per microsecond and an overflow in almost 30min
+ */
+#define TIMER_CLOCK            (24 * 100 * 1000)
+#define COUNT_TO_USEC(x)       ((x) * 5 / 12)  /* overflows at 6min */
+#define USEC_TO_COUNT(x)       ((x) * 12 / 5)  /* overflows at 6min */
+#define TICKS_PER_HZ           (TIMER_CLOCK / CONFIG_SYS_HZ)
+#define TICKS_TO_HZ(x)         ((x) / TICKS_PER_HZ)
+
+/* macro to read the decrementing 32 bit timer as an increasing count */
+#define READ_TIMER() (0 - readl(CONFIG_SYS_TIMERBASE + MTU_VAL(0)))
+
+/* Configure a free-running, auto-wrap counter with no prescaler */
+int timer_init(void)
+{
+       ulong val;
+
+       writel(MTU_CRn_ENA | MTU_CRn_PRESCALE_1 | MTU_CRn_32BITS,
+              CONFIG_SYS_TIMERBASE + MTU_CR(0));
+
+       /* Reset the timer */
+       writel(0, CONFIG_SYS_TIMERBASE + MTU_LR(0));
+       /*
+        * The load-register isn't really immediate: it changes on clock
+        * edges, so we must wait for our newly-written value to appear.
+        * Since we might miss reading 0, wait for any change in value.
+        */
+       val = READ_TIMER();
+       while (READ_TIMER() == val)
+               ;
+
+       return 0;
+}
+
+/* Return how many HZ passed since "base" */
+ulong get_timer(ulong base)
+{
+       return  TICKS_TO_HZ(READ_TIMER()) - base;
+}
+
+/* Delay x useconds */
+void __udelay(unsigned long usec)
+{
+       ulong ini, end;
+
+       ini = READ_TIMER();
+       end = ini + USEC_TO_COUNT(usec);
+       while ((signed)(end - READ_TIMER()) > 0)
+               ;
+}
+
+unsigned long long get_ticks(void)
+{
+       return get_timer(0);
+}
+
+ulong get_tbclk(void)
+{
+       return CONFIG_SYS_HZ;
+}