1 files changed, 77 insertions, 73 deletions

diff --git a/arch/avr32/kernel/time.c b/arch/avr32/kernel/time.c
index c10833f2ee0c..7014a3571ec0 100644
--- a/arch/avr32/kernel/time.c
+++ b/arch/avr32/kernel/time.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2004-2006 Atmel Corporation
+ * Copyright (C) 2004-2007 Atmel Corporation
  *
  * Based on MIPS implementation arch/mips/kernel/time.c
  *   Copyright 2001 MontaVista Software Inc.
@@ -20,18 +20,25 @@
 #include <linux/init.h>
 #include <linux/profile.h>
 #include <linux/sysdev.h>
+#include <linux/err.h>
 
 #include <asm/div64.h>
 #include <asm/sysreg.h>
 #include <asm/io.h>
 #include <asm/sections.h>
 
-static cycle_t read_cycle_count(void)
+/* how many counter cycles in a jiffy? */
+static u32 cycles_per_jiffy;
+
+/* the count value for the next timer interrupt */
+static u32 expirelo;
+
+cycle_t __weak read_cycle_count(void)
 {
         return (cycle_t)sysreg_read(COUNT);
 }
 
-static struct clocksource clocksource_avr32 = {
+struct clocksource __weak clocksource_avr32 = {
         .name           = "avr32",
         .rating         = 350,
         .read           = read_cycle_count,
@@ -40,12 +47,20 @@ static struct clocksource clocksource_avr32 = {
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
+irqreturn_t __weak timer_interrupt(int irq, void *dev_id);
+
+struct irqaction timer_irqaction = {
+        .handler        = timer_interrupt,
+        .flags          = IRQF_DISABLED,
+        .name           = "timer",
+};
+
 /*
  * By default we provide the null RTC ops
  */
 static unsigned long null_rtc_get_time(void)
 {
-        return mktime(2004, 1, 1, 0, 0, 0);
+        return mktime(2007, 1, 1, 0, 0, 0);
 }
 
 static int null_rtc_set_time(unsigned long sec)
@@ -56,23 +71,14 @@ static int null_rtc_set_time(unsigned long sec)
 static unsigned long (*rtc_get_time)(void) = null_rtc_get_time;
 static int (*rtc_set_time)(unsigned long) = null_rtc_set_time;
 
-/* how many counter cycles in a jiffy? */
-static unsigned long cycles_per_jiffy;
-
-/* cycle counter value at the previous timer interrupt */
-static unsigned int timerhi, timerlo;
-
-/* the count value for the next timer interrupt */
-static unsigned int expirelo;
-
 static void avr32_timer_ack(void)
 {
-        unsigned int count;
+        u32 count;
 
         /* Ack this timer interrupt and set the next one */
         expirelo += cycles_per_jiffy;
+        /* setting COMPARE to 0 stops the COUNT-COMPARE */
         if (expirelo == 0) {
-                printk(KERN_DEBUG "expirelo == 0\n");
                 sysreg_write(COMPARE, expirelo + 1);
         } else {
                 sysreg_write(COMPARE, expirelo);
@@ -86,27 +92,56 @@ static void avr32_timer_ack(void)
         }
 }
 
-static unsigned int avr32_hpt_read(void)
+int __weak avr32_hpt_init(void)
 {
-        return sysreg_read(COUNT);
+        int ret;
+        unsigned long mult, shift, count_hz;
+
+        count_hz = clk_get_rate(boot_cpu_data.clk);
+        shift = clocksource_avr32.shift;
+        mult = clocksource_hz2mult(count_hz, shift);
+        clocksource_avr32.mult = mult;
+
+        {
+                u64 tmp;
+
+                tmp = TICK_NSEC;
+                tmp <<= shift;
+                tmp += mult / 2;
+                do_div(tmp, mult);
+
+                cycles_per_jiffy = tmp;
+        }
+
+        ret = setup_irq(0, &timer_irqaction);
+        if (ret) {
+                pr_debug("timer: could not request IRQ 0: %d\n", ret);
+                return -ENODEV;
+        }
+
+        printk(KERN_INFO "timer: AT32AP COUNT-COMPARE at irq 0, "
+                        "%lu.%03lu MHz\n",
+                        ((count_hz + 500) / 1000) / 1000,
+                        ((count_hz + 500) / 1000) % 1000);
+
+        return 0;
 }
 
 /*
  * Taken from MIPS c0_hpt_timer_init().
  *
- * Why is it so complicated, and what is "count"?  My assumption is
- * that `count' specifies the "reference cycle", i.e. the cycle since
- * reset that should mean "zero". The reason COUNT is written twice is
- * probably to make sure we don't get any timer interrupts while we
- * are messing with the counter.
+ * The reason COUNT is written twice is probably to make sure we don't get any
+ * timer interrupts while we are messing with the counter.
  */
-static void avr32_hpt_init(unsigned int count)
+int __weak avr32_hpt_start(void)
 {
-        count = sysreg_read(COUNT) - count;
+        u32 count = sysreg_read(COUNT);
         expirelo = (count / cycles_per_jiffy + 1) * cycles_per_jiffy;
         sysreg_write(COUNT, expirelo - cycles_per_jiffy);
         sysreg_write(COMPARE, expirelo);
         sysreg_write(COUNT, count);
+
+        return 0;
 }
 
 /*
@@ -115,26 +150,18 @@ static void avr32_hpt_init(unsigned int count)
  *
  * In UP mode, it is invoked from the (global) timer_interrupt.
  */
-static void local_timer_interrupt(int irq, void *dev_id)
+void local_timer_interrupt(int irq, void *dev_id)
 {
         if (current->pid)
                 profile_tick(CPU_PROFILING);
         update_process_times(user_mode(get_irq_regs()));
 }
 
-static irqreturn_t
-timer_interrupt(int irq, void *dev_id)
+irqreturn_t __weak timer_interrupt(int irq, void *dev_id)
 {
-        unsigned int count;
-
         /* ack timer interrupt and try to set next interrupt */
-        count = avr32_hpt_read();
         avr32_timer_ack();
 
-        /* Update timerhi/timerlo for intra-jiffy calibration */
-        timerhi += count < timerlo;     /* Wrap around */
-        timerlo = count;
-
         /*
          * Call the generic timer interrupt handler
          */
@@ -153,60 +180,37 @@ timer_interrupt(int irq, void *dev_id)
         return IRQ_HANDLED;
 }
 
-static struct irqaction timer_irqaction = {
-        .handler        = timer_interrupt,
-        .flags          = IRQF_DISABLED,
-        .name           = "timer",
-};
-
 void __init time_init(void)
 {
-        unsigned long mult, shift, count_hz;
         int ret;
 
+        /*
+         * Make sure we don't get any COMPARE interrupts before we can
+         * handle them.
+         */
+        sysreg_write(COMPARE, 0);
+
         xtime.tv_sec = rtc_get_time();
         xtime.tv_nsec = 0;
 
         set_normalized_timespec(&wall_to_monotonic,
                                 -xtime.tv_sec, -xtime.tv_nsec);
 
-        printk("Before time_init: count=%08lx, compare=%08lx\n",
-               (unsigned long)sysreg_read(COUNT),
-               (unsigned long)sysreg_read(COMPARE));
-
-        count_hz = clk_get_rate(boot_cpu_data.clk);
-        shift = clocksource_avr32.shift;
-        mult = clocksource_hz2mult(count_hz, shift);
-        clocksource_avr32.mult = mult;
-
-        printk("Cycle counter: mult=%lu, shift=%lu\n", mult, shift);
-
-        {
-                u64 tmp;
-
-                tmp = TICK_NSEC;
-                tmp <<= shift;
-                tmp += mult / 2;
-                do_div(tmp, mult);
-
-                cycles_per_jiffy = tmp;
+        ret = avr32_hpt_init();
+        if (ret) {
+                pr_debug("timer: failed setup: %d\n", ret);
+                return;
         }
 
-        /* This sets up the high precision timer for the first interrupt. */
-        avr32_hpt_init(avr32_hpt_read());
-
-        printk("After time_init: count=%08lx, compare=%08lx\n",
-               (unsigned long)sysreg_read(COUNT),
-               (unsigned long)sysreg_read(COMPARE));
-
         ret = clocksource_register(&clocksource_avr32);
         if (ret)
-                printk(KERN_ERR
-                       "timer: could not register clocksource: %d\n", ret);
+                pr_debug("timer: could not register clocksource: %d\n", ret);
 
-        ret = setup_irq(0, &timer_irqaction);
-        if (ret)
-                printk("timer: could not request IRQ 0: %d\n", ret);
+        ret = avr32_hpt_start();
+        if (ret) {
+                pr_debug("timer: failed starting: %d\n", ret);
+                return;
+        }
 }
 
 static struct sysdev_class timer_class = {