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authorYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>2008-04-24 09:48:40 +0900
committerRalf Baechle <ralf@linux-mips.org>2008-04-28 17:14:32 +0100
commit4247417d8457b326ede001cb74af8570b5aa302b (patch)
treed52e4b8e5c7a8fe6d353234984d6414c9982b987 /arch/mips/kernel
parent05a96fae433a662e12879b543a6838b6c2129402 (diff)
[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>
Diffstat (limited to 'arch/mips/kernel')
-rw-r--r--arch/mips/kernel/Makefile1
-rw-r--r--arch/mips/kernel/csrc-ioasic.c65
2 files changed, 66 insertions, 0 deletions
diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile
index 87067e8fee9e..00ac35e501b3 100644
--- a/arch/mips/kernel/Makefile
+++ b/arch/mips/kernel/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_CEVT_GT641XX) += cevt-gt641xx.o
obj-$(CONFIG_CEVT_SB1250) += cevt-sb1250.o
obj-$(CONFIG_CEVT_TXX9) += cevt-txx9.o
obj-$(CONFIG_CSRC_BCM1480) += csrc-bcm1480.o
+obj-$(CONFIG_CSRC_IOASIC) += csrc-ioasic.o
obj-$(CONFIG_CSRC_R4K) += csrc-r4k.o
obj-$(CONFIG_CSRC_SB1250) += csrc-sb1250.o
obj-$(CONFIG_SYNC_R4K) += sync-r4k.o
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);
+}