arm: add support for arch timer

This patch add basic support for the architecture timer found on recent
ARMv7 based SoCs.

Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>

arch/arm/cpu/armv7/Makefile

@@ -25,6 +25,7 @@ endif
 
 obj-$(CONFIG_KONA) += kona-common/
 obj-$(CONFIG_OMAP_COMMON) += omap-common/
+obj-$(CONFIG_SYS_ARCH_TIMER) += arch_timer.o
 obj-$(CONFIG_TEGRA) += tegra-common/
 
 ifneq (,$(filter s5pc1xx exynos,$(SOC)))

arch/arm/cpu/armv7/arch_timer.c

@@ -0,0 +1,58 @@
+/*
+ * (C) Copyright 2012-2014
+ *     Texas Instruments Incorporated, <www.ti.com>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <div64.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int timer_init(void)
+{
+	gd->arch.tbl = 0;
+	gd->arch.tbu = 0;
+
+	gd->arch.timer_rate_hz = CONFIG_SYS_HZ_CLOCK / CONFIG_SYS_HZ;
+
+	return 0;
+}
+
+unsigned long long get_ticks(void)
+{
+	ulong nowl, nowu;
+
+	asm volatile("mrrc p15, 0, %0, %1, c14" : "=r" (nowl), "=r" (nowu));
+
+	gd->arch.tbl = nowl;
+	gd->arch.tbu = nowu;
+
+	return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
+}
+
+
+ulong get_timer(ulong base)
+{
+	return lldiv(get_ticks(), gd->arch.timer_rate_hz) - base;
+}
+
+void __udelay(unsigned long usec)
+{
+	unsigned long long endtime;
+
+	endtime = lldiv((unsigned long long)usec * gd->arch.timer_rate_hz,
+			1000UL);
+
+	endtime += get_ticks();
+
+	while (get_ticks() < endtime)
+		;
+}
+
+ulong get_tbclk(void)
+{
+	return gd->arch.timer_rate_hz;
+}