1 files changed, 107 insertions, 0 deletions
diff --git a/arch/x86/lib/tsc_timer.c b/arch/x86/lib/tsc_timer.c
new file mode 100644
index 0000000000..c509801f9e
--- /dev/null
+++ b/arch/x86/lib/tsc_timer.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2012 The Chromium OS Authors.
+ *
+ * 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 <malloc.h>
+#include <asm/io.h>
+#include <asm/i8254.h>
+#include <asm/ibmpc.h>
+#include <asm/msr.h>
+#include <asm/u-boot-x86.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+void timer_set_base(u64 base)
+{
+	gd->arch.tsc_base = base;
+}
+
+/*
+ * Get the number of CPU time counter ticks since it was read first time after
+ * restart. This yields a free running counter guaranteed to take almost 6
+ * years to wrap around even at 100GHz clock rate.
+ */
+u64 get_ticks(void)
+{
+	u64 now_tick = rdtsc();
+
+	/* We assume that 0 means the base hasn't been set yet */
+	if (!gd->arch.tsc_base)
+		panic("No tick base available");
+	return now_tick - gd->arch.tsc_base;
+}
+
+#define PLATFORM_INFO_MSR 0xce
+
+/* Get the speed of the TSC timer in MHz */
+unsigned long get_tbclk_mhz(void)
+{
+	u32 ratio;
+	u64 platform_info = native_read_msr(PLATFORM_INFO_MSR);
+
+	/* 100MHz times Max Non Turbo ratio */
+	ratio = (platform_info >> 8) & 0xff;
+	return 100 * ratio;
+}
+
+unsigned long get_tbclk(void)
+{
+	return get_tbclk_mhz() * 1000 * 1000;
+}
+
+static ulong get_ms_timer(void)
+{
+	return (get_ticks() * 1000) / get_tbclk();
+}
+
+ulong get_timer(ulong base)
+{
+	return get_ms_timer() - base;
+}
+
+ulong timer_get_us(void)
+{
+	return get_ticks() / get_tbclk_mhz();
+}
+
+ulong timer_get_boot_us(void)
+{
+	return timer_get_us();
+}
+
+void __udelay(unsigned long usec)
+{
+	u64 now = get_ticks();
+	u64 stop;
+
+	stop = now + usec * get_tbclk_mhz();
+
+	while ((int64_t)(stop - get_ticks()) > 0)
+		;
+}
+
+int timer_init(void)
+{
+#ifdef CONFIG_SYS_PCAT_TIMER
+	/* Set up the PCAT timer if required */
+	pcat_timer_init();
+#endif
+
+	return 0;
+}