This builds on some of the clock framework code to support a simple
system timer interface.
Signed-off-by: Paul Mundt <[email protected]>
---
arch/sh/kernel/timers/Makefile | 8 +
arch/sh/kernel/timers/timer-tmu.c | 229 ++++++++++++++++++++++++++++++++++++++
arch/sh/kernel/timers/timer.c | 50 ++++++++
include/asm-sh/timer.h | 42 ++++++
4 files changed, 329 insertions(+)
diff -urN -X exclude linux-2.6.15/arch/sh/kernel/timers/Makefile sh-2.6.15/arch/sh/kernel/timers/Makefile
--- linux-2.6.15/arch/sh/kernel/timers/Makefile 1970-01-01 02:00:00.000000000 +0200
+++ sh-2.6.15/arch/sh/kernel/timers/Makefile 2006-01-04 00:15:28.000000000 +0200
@@ -0,0 +1,8 @@
+#
+# Makefile for the various Linux/SuperH timers
+#
+
+obj-y := timer.o
+
+obj-$(CONFIG_SH_TMU) += timer-tmu.o
+
diff -urN -X exclude linux-2.6.15/arch/sh/kernel/timers/timer-tmu.c sh-2.6.15/arch/sh/kernel/timers/timer-tmu.c
--- linux-2.6.15/arch/sh/kernel/timers/timer-tmu.c 1970-01-01 02:00:00.000000000 +0200
+++ sh-2.6.15/arch/sh/kernel/timers/timer-tmu.c 2006-01-04 00:15:28.000000000 +0200
@@ -0,0 +1,229 @@
+/*
+ * arch/sh/kernel/timers/timer-tmu.c - TMU Timer Support
+ *
+ * Copyright (C) 2005 Paul Mundt
+ *
+ * TMU handling code hacked out of arch/sh/kernel/time.c
+ *
+ * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
+ * Copyright (C) 2000 Philipp Rumpf <[email protected]>
+ * Copyright (C) 2002, 2003, 2004 Paul Mundt
+ * Copyright (C) 2002 M. R. Brown <[email protected]>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/seqlock.h>
+#include <asm/timer.h>
+#include <asm/rtc.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/clock.h>
+
+#define TMU_TOCR_INIT 0x00
+#define TMU0_TCR_INIT 0x0020
+#define TMU_TSTR_INIT 1
+
+#define TMU0_TCR_CALIB 0x0000
+
+static DEFINE_SPINLOCK(tmu0_lock);
+
+static unsigned long tmu_timer_get_offset(void)
+{
+ int count;
+ unsigned long flags;
+
+ static int count_p = 0x7fffffff; /* for the first call after boot */
+ static unsigned long jiffies_p = 0;
+
+ /*
+ * cache volatile jiffies temporarily; we have IRQs turned off.
+ */
+ unsigned long jiffies_t;
+
+ spin_lock_irqsave(&tmu0_lock, flags);
+ /* timer count may underflow right here */
+ count = ctrl_inl(TMU0_TCNT); /* read the latched count */
+
+ jiffies_t = jiffies;
+
+ /*
+ * avoiding timer inconsistencies (they are rare, but they happen)...
+ * there is one kind of problem that must be avoided here:
+ * 1. the timer counter underflows
+ */
+
+ if (jiffies_t == jiffies_p) {
+ if (count > count_p) {
+ /* the nutcase */
+ if (ctrl_inw(TMU0_TCR) & 0x100) { /* Check UNF bit */
+ count -= LATCH;
+ } else {
+ printk("%s (): hardware timer problem?\n",
+ __FUNCTION__);
+ }
+ }
+ } else
+ jiffies_p = jiffies_t;
+
+ count_p = count;
+ spin_unlock_irqrestore(&tmu0_lock, flags);
+
+ count = ((LATCH-1) - count) * TICK_SIZE;
+ count = (count + LATCH/2) / LATCH;
+
+ return count;
+}
+
+static irqreturn_t tmu_timer_interrupt(int irq, void *dev_id,
+ struct pt_regs *regs)
+{
+ unsigned long timer_status;
+
+ /* Clear UNF bit */
+ timer_status = ctrl_inw(TMU0_TCR);
+ timer_status &= ~0x100;
+ ctrl_outw(timer_status, TMU0_TCR);
+
+ /*
+ * Here we are in the timer irq handler. We just have irqs locally
+ * disabled but we don't know if the timer_bh is running on the other
+ * CPU. We need to avoid to SMP race with it. NOTE: we don' t need
+ * the irq version of write_lock because as just said we have irq
+ * locally disabled. -arca
+ */
+ write_seqlock(&xtime_lock);
+ handle_timer_tick(regs);
+ write_sequnlock(&xtime_lock);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction tmu_irq = {
+ .name = "timer",
+ .handler = tmu_timer_interrupt,
+ .flags = SA_INTERRUPT,
+ .mask = CPU_MASK_NONE,
+};
+
+/*
+ * Hah! We'll see if this works (switching from usecs to nsecs).
+ */
+static unsigned long tmu_timer_get_frequency(void)
+{
+ u32 freq;
+ struct timespec ts1, ts2;
+ unsigned long diff_nsec;
+ unsigned long factor;
+
+ /* Setup the timer: We don't want to generate interrupts, just
+ * have it count down at its natural rate.
+ */
+ ctrl_outb(0, TMU_TSTR);
+#if !defined(CONFIG_CPU_SUBTYPE_SH7300) && !defined(CONFIG_CPU_SUBTYPE_SH7760)
+ ctrl_outb(TMU_TOCR_INIT, TMU_TOCR);
+#endif
+ ctrl_outw(TMU0_TCR_CALIB, TMU0_TCR);
+ ctrl_outl(0xffffffff, TMU0_TCOR);
+ ctrl_outl(0xffffffff, TMU0_TCNT);
+
+ rtc_get_time(&ts2);
+
+ do {
+ rtc_get_time(&ts1);
+ } while (ts1.tv_nsec == ts2.tv_nsec && ts1.tv_sec == ts2.tv_sec);
+
+ /* actually start the timer */
+ ctrl_outb(TMU_TSTR_INIT, TMU_TSTR);
+
+ do {
+ rtc_get_time(&ts2);
+ } while (ts1.tv_nsec == ts2.tv_nsec && ts1.tv_sec == ts2.tv_sec);
+
+ freq = 0xffffffff - ctrl_inl(TMU0_TCNT);
+ if (ts2.tv_nsec < ts1.tv_nsec) {
+ ts2.tv_nsec += 1000000000;
+ ts2.tv_sec--;
+ }
+
+ diff_nsec = (ts2.tv_sec - ts1.tv_sec) * 1000000000 + (ts2.tv_nsec - ts1.tv_nsec);
+
+ /* this should work well if the RTC has a precision of n Hz, where
+ * n is an integer. I don't think we have to worry about the other
+ * cases. */
+ factor = (1000000000 + diff_nsec/2) / diff_nsec;
+
+ if (factor * diff_nsec > 1100000000 ||
+ factor * diff_nsec < 900000000)
+ panic("weird RTC (diff_nsec %ld)", diff_nsec);
+
+ return freq * factor;
+}
+
+static void tmu_clk_init(struct clk *clk)
+{
+ u8 divisor = TMU0_TCR_INIT & 0x7;
+ ctrl_outw(TMU0_TCR_INIT, TMU0_TCR);
+ clk->rate = clk->parent->rate / (4 << (divisor << 1));
+}
+
+static void tmu_clk_recalc(struct clk *clk)
+{
+ u8 divisor = ctrl_inw(TMU0_TCR) & 0x7;
+ clk->rate = clk->parent->rate / (4 << (divisor << 1));
+}
+
+static struct clk_ops tmu_clk_ops = {
+ .init = tmu_clk_init,
+ .recalc = tmu_clk_recalc,
+};
+
+static struct clk tmu0_clk = {
+ .name = "tmu0_clk",
+ .ops = &tmu_clk_ops,
+};
+
+static int tmu_timer_init(void)
+{
+ unsigned long interval;
+
+ setup_irq(TIMER_IRQ, &tmu_irq);
+
+ tmu0_clk.parent = clk_get("module_clk");
+
+ /* Start TMU0 */
+ ctrl_outb(0, TMU_TSTR);
+#if !defined(CONFIG_CPU_SUBTYPE_SH7300) && !defined(CONFIG_CPU_SUBTYPE_SH7760)
+ ctrl_outb(TMU_TOCR_INIT, TMU_TOCR);
+#endif
+
+ clk_register(&tmu0_clk);
+ clk_enable(&tmu0_clk);
+
+ interval = (clk_get_rate(&tmu0_clk) + HZ / 2) / HZ;
+ printk(KERN_INFO "Interval = %ld\n", interval);
+
+ ctrl_outl(interval, TMU0_TCOR);
+ ctrl_outl(interval, TMU0_TCNT);
+
+ ctrl_outb(TMU_TSTR_INIT, TMU_TSTR);
+
+ return 0;
+}
+
+struct sys_timer_ops tmu_timer_ops = {
+ .init = tmu_timer_init,
+ .get_frequency = tmu_timer_get_frequency,
+ .get_offset = tmu_timer_get_offset,
+};
+
+struct sys_timer tmu_timer = {
+ .name = "tmu",
+ .ops = &tmu_timer_ops,
+};
+
diff -urN -X exclude linux-2.6.15/arch/sh/kernel/timers/timer.c sh-2.6.15/arch/sh/kernel/timers/timer.c
--- linux-2.6.15/arch/sh/kernel/timers/timer.c 1970-01-01 02:00:00.000000000 +0200
+++ sh-2.6.15/arch/sh/kernel/timers/timer.c 2006-01-04 00:15:28.000000000 +0200
@@ -0,0 +1,50 @@
+/*
+ * arch/sh/kernel/timers/timer.c - Common timer code
+ *
+ * Copyright (C) 2005 Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <asm/timer.h>
+
+static struct sys_timer *sys_timers[] __initdata = {
+#ifdef CONFIG_SH_TMU
+ &tmu_timer,
+#endif
+ NULL,
+};
+
+static char timer_override[10] __initdata;
+static int __init timer_setup(char *str)
+{
+ if (str)
+ strlcpy(timer_override, str, sizeof(timer_override));
+ return 1;
+}
+__setup("timer=", timer_setup);
+
+struct sys_timer *get_sys_timer(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(sys_timers); i++) {
+ struct sys_timer *t = sys_timers[i];
+
+ if (unlikely(!t))
+ break;
+ if (unlikely(timer_override[0]))
+ if ((strcmp(timer_override, t->name) != 0))
+ continue;
+ if (likely(t->ops->init() == 0))
+ return t;
+ }
+
+ return NULL;
+}
+
diff -urN -X exclude linux-2.6.15/include/asm-sh/timer.h sh-2.6.15/include/asm-sh/timer.h
--- linux-2.6.15/include/asm-sh/timer.h 1970-01-01 02:00:00.000000000 +0200
+++ sh-2.6.15/include/asm-sh/timer.h 2006-01-04 00:15:30.000000000 +0200
@@ -0,0 +1,42 @@
+#ifndef __ASM_SH_TIMER_H
+#define __ASM_SH_TIMER_H
+
+#include <linux/sysdev.h>
+#include <asm/cpu/timer.h>
+
+struct sys_timer_ops {
+ int (*init)(void);
+ unsigned long (*get_offset)(void);
+ unsigned long (*get_frequency)(void);
+};
+
+struct sys_timer {
+ const char *name;
+
+ struct sys_device dev;
+ struct sys_timer_ops *ops;
+};
+
+#define TICK_SIZE (tick_nsec / 1000)
+
+extern struct sys_timer tmu_timer;
+extern struct sys_timer *sys_timer;
+
+static inline unsigned long get_timer_offset(void)
+{
+ return sys_timer->ops->get_offset();
+}
+
+static inline unsigned long get_timer_frequency(void)
+{
+ return sys_timer->ops->get_frequency();
+}
+
+/* arch/sh/kernel/timers/timer.c */
+struct sys_timer *get_sys_timer(void);
+
+/* arch/sh/kernel/time.c */
+void handle_timer_tick(struct pt_regs *);
+
+#endif /* __ASM_SH_TIMER_H */
+
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
