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authorShinya Kuribayashi <skuribay@pobox.com>2011-05-07 00:18:13 +0900
committerShinya Kuribayashi <skuribay@pobox.com>2011-05-10 00:12:31 +0900
commit68cebb8027c282a949ac0ca7dcb5baabd1c6879a (patch)
tree43082c3da2b94caab4622480520465e0855e65a9 /arch/mips/cpu
parent660da0947abff3bc98bb0baa37a6db5050ff46d6 (diff)
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MIPS: Move timer code to arch/mips/cpu/$(CPU)/
Current timer routines (arch/mips/lib/timer.c) are implemented assuming that MIPS32 coprocessor (CP0) resources, Counter and Compare registers in this case, are available. But this doesn't always work. We need to make sure that all MIPS-based systems don't necessarily use CP0 counter/compare registers as time keeping resources. And some MIPS variant processors might come with different hardware specs with genuine MIPS32 CP0 registers. With this change, each $(CPU)/ directory can have its own timer code. Signed-off-by: Shinya Kuribayashi <skuribay@pobox.com>
Diffstat (limited to 'arch/mips/cpu')
-rw-r--r--arch/mips/cpu/mips32/Makefile2
-rw-r--r--arch/mips/cpu/mips32/time.c98
2 files changed, 99 insertions, 1 deletions
diff --git a/arch/mips/cpu/mips32/Makefile b/arch/mips/cpu/mips32/Makefile
index e315c1b..eb8e005 100644
--- a/arch/mips/cpu/mips32/Makefile
+++ b/arch/mips/cpu/mips32/Makefile
@@ -27,7 +27,7 @@ LIB = $(obj)lib$(CPU).o
START = start.o
SOBJS-y = cache.o
-COBJS-y = cpu.o interrupts.o
+COBJS-y = cpu.o interrupts.o time.o
SRCS := $(START:.o=.S) $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
OBJS := $(addprefix $(obj),$(SOBJS-y) $(COBJS-y))
diff --git a/arch/mips/cpu/mips32/time.c b/arch/mips/cpu/mips32/time.c
new file mode 100644
index 0000000..0e66441
--- /dev/null
+++ b/arch/mips/cpu/mips32/time.c
@@ -0,0 +1,98 @@
+/*
+ * (C) Copyright 2003
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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 <asm/mipsregs.h>
+
+static unsigned long timestamp;
+
+/* how many counter cycles in a jiffy */
+#define CYCLES_PER_JIFFY (CONFIG_SYS_MIPS_TIMER_FREQ + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ
+
+/*
+ * timer without interrupts
+ */
+
+int timer_init(void)
+{
+ /* Set up the timer for the first expiration. */
+ timestamp = 0;
+ write_c0_compare(read_c0_count() + CYCLES_PER_JIFFY);
+
+ return 0;
+}
+
+void reset_timer(void)
+{
+ timestamp = 0;
+ write_c0_compare(read_c0_count() + CYCLES_PER_JIFFY);
+}
+
+ulong get_timer(ulong base)
+{
+ unsigned int count;
+ unsigned int expirelo = read_c0_compare();
+
+ /* Check to see if we have missed any timestamps. */
+ count = read_c0_count();
+ while ((count - expirelo) < 0x7fffffff) {
+ expirelo += CYCLES_PER_JIFFY;
+ timestamp++;
+ }
+ write_c0_compare(expirelo);
+
+ return (timestamp - base);
+}
+
+void set_timer(ulong t)
+{
+ timestamp = t;
+ write_c0_compare(read_c0_count() + CYCLES_PER_JIFFY);
+}
+
+void __udelay(unsigned long usec)
+{
+ unsigned int tmo;
+
+ tmo = read_c0_count() + (usec * (CONFIG_SYS_MIPS_TIMER_FREQ / 1000000));
+ while ((tmo - read_c0_count()) < 0x7fffffff)
+ /*NOP*/;
+}
+
+/*
+ * This function is derived from PowerPC code (read timebase as long long).
+ * On MIPS it just returns the timer value.
+ */
+unsigned long long get_ticks(void)
+{
+ return get_timer(0);
+}
+
+/*
+ * This function is derived from PowerPC code (timebase clock frequency).
+ * On MIPS it returns the number of timer ticks per second.
+ */
+ulong get_tbclk(void)
+{
+ return CONFIG_SYS_HZ;
+}