From 4247417d8457b326ede001cb74af8570b5aa302b Mon Sep 17 00:00:00 2001
From: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Date: Thu, 24 Apr 2008 09:48:40 +0900
Subject: [MIPS] add DECstation I/O ASIC clocksource
Add DECstation I/O ASIC clocksource
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/kernel/csrc-ioasic.c | 65 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 65 insertions(+)
create mode 100644 arch/mips/kernel/csrc-ioasic.c
(limited to 'arch/mips/kernel/csrc-ioasic.c')
diff --git a/arch/mips/kernel/csrc-ioasic.c b/arch/mips/kernel/csrc-ioasic.c
new file mode 100644
index 000000000000..1d5f63cf8997
--- /dev/null
+++ b/arch/mips/kernel/csrc-ioasic.c
@@ -0,0 +1,65 @@
+/*
+ * DEC I/O ASIC's counter clocksource
+ *
+ * Copyright (C) 2008 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include <linux/clocksource.h>
+#include <linux/init.h>
+
+#include <asm/ds1287.h>
+#include <asm/time.h>
+#include <asm/dec/ioasic.h>
+#include <asm/dec/ioasic_addrs.h>
+
+static cycle_t dec_ioasic_hpt_read(void)
+{
+ return ioasic_read(IO_REG_FCTR);
+}
+
+static struct clocksource clocksource_dec = {
+ .name = "dec-ioasic",
+ .read = dec_ioasic_hpt_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+void __init dec_ioasic_clocksource_init(void)
+{
+ unsigned int freq;
+ u32 start, end;
+ int i = HZ / 10;
+
+
+ while (!ds1287_timer_state())
+ ;
+
+ start = dec_ioasic_hpt_read();
+
+ while (i--)
+ while (!ds1287_timer_state())
+ ;
+
+ end = dec_ioasic_hpt_read();
+
+ freq = (end - start) * 10;
+ printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq);
+
+ clocksource_dec.rating = 200 + freq / 10000000;
+ clocksource_set_clock(&clocksource_dec, freq);
+
+ clocksource_register(&clocksource_dec);
+}
--
cgit