1 files changed, 259 insertions, 0 deletions
diff --git a/arch/i386/kernel/timers/timer_cyclone.c b/arch/i386/kernel/timers/timer_cyclone.c
new file mode 100644
index 000000000000..f6f1206a11bb
--- /dev/null
+++ b/arch/i386/kernel/timers/timer_cyclone.c
@@ -0,0 +1,259 @@
+/*	Cyclone-timer: 
+ *		This code implements timer_ops for the cyclone counter found
+ *		on IBM x440, x360, and other Summit based systems.
+ *
+ *	Copyright (C) 2002 IBM, John Stultz (johnstul@us.ibm.com)
+ */
+
+
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/timex.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/jiffies.h>
+
+#include <asm/timer.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/fixmap.h>
+#include "io_ports.h"
+
+extern spinlock_t i8253_lock;
+
+/* Number of usecs that the last interrupt was delayed */
+static int delay_at_last_interrupt;
+
+#define CYCLONE_CBAR_ADDR 0xFEB00CD0
+#define CYCLONE_PMCC_OFFSET 0x51A0
+#define CYCLONE_MPMC_OFFSET 0x51D0
+#define CYCLONE_MPCS_OFFSET 0x51A8
+#define CYCLONE_TIMER_FREQ 100000000
+#define CYCLONE_TIMER_MASK (((u64)1<<40)-1) /* 40 bit mask */
+int use_cyclone = 0;
+
+static u32* volatile cyclone_timer;	/* Cyclone MPMC0 register */
+static u32 last_cyclone_low;
+static u32 last_cyclone_high;
+static unsigned long long monotonic_base;
+static seqlock_t monotonic_lock = SEQLOCK_UNLOCKED;
+
+/* helper macro to atomically read both cyclone counter registers */
+#define read_cyclone_counter(low,high) \
+	do{ \
+		high = cyclone_timer[1]; low = cyclone_timer[0]; \
+	} while (high != cyclone_timer[1]);
+
+
+static void mark_offset_cyclone(void)
+{
+	unsigned long lost, delay;
+	unsigned long delta = last_cyclone_low;
+	int count;
+	unsigned long long this_offset, last_offset;
+
+	write_seqlock(&monotonic_lock);
+	last_offset = ((unsigned long long)last_cyclone_high<<32)|last_cyclone_low;
+	
+	spin_lock(&i8253_lock);
+	read_cyclone_counter(last_cyclone_low,last_cyclone_high);
+
+	/* read values for delay_at_last_interrupt */
+	outb_p(0x00, 0x43);     /* latch the count ASAP */
+
+	count = inb_p(0x40);    /* read the latched count */
+	count |= inb(0x40) << 8;
+
+	/*
+	 * VIA686a test code... reset the latch if count > max + 1
+	 * from timer_pit.c - cjb
+	 */
+	if (count > LATCH) {
+		outb_p(0x34, PIT_MODE);
+		outb_p(LATCH & 0xff, PIT_CH0);
+		outb(LATCH >> 8, PIT_CH0);
+		count = LATCH - 1;
+	}
+	spin_unlock(&i8253_lock);
+
+	/* lost tick compensation */
+	delta = last_cyclone_low - delta;	
+	delta /= (CYCLONE_TIMER_FREQ/1000000);
+	delta += delay_at_last_interrupt;
+	lost = delta/(1000000/HZ);
+	delay = delta%(1000000/HZ);
+	if (lost >= 2)
+		jiffies_64 += lost-1;
+	
+	/* update the monotonic base value */
+	this_offset = ((unsigned long long)last_cyclone_high<<32)|last_cyclone_low;
+	monotonic_base += (this_offset - last_offset) & CYCLONE_TIMER_MASK;
+	write_sequnlock(&monotonic_lock);
+
+	/* calculate delay_at_last_interrupt */
+	count = ((LATCH-1) - count) * TICK_SIZE;
+	delay_at_last_interrupt = (count + LATCH/2) / LATCH;
+
+
+	/* catch corner case where tick rollover occured 
+	 * between cyclone and pit reads (as noted when 
+	 * usec delta is > 90% # of usecs/tick)
+	 */
+	if (lost && abs(delay - delay_at_last_interrupt) > (900000/HZ))
+		jiffies_64++;
+}
+
+static unsigned long get_offset_cyclone(void)
+{
+	u32 offset;
+
+	if(!cyclone_timer)
+		return delay_at_last_interrupt;
+
+	/* Read the cyclone timer */
+	offset = cyclone_timer[0];
+
+	/* .. relative to previous jiffy */
+	offset = offset - last_cyclone_low;
+
+	/* convert cyclone ticks to microseconds */	
+	/* XXX slow, can we speed this up? */
+	offset = offset/(CYCLONE_TIMER_FREQ/1000000);
+
+	/* our adjusted time offset in microseconds */
+	return delay_at_last_interrupt + offset;
+}
+
+static unsigned long long monotonic_clock_cyclone(void)
+{
+	u32 now_low, now_high;
+	unsigned long long last_offset, this_offset, base;
+	unsigned long long ret;
+	unsigned seq;
+
+	/* atomically read monotonic base & last_offset */
+	do {
+		seq = read_seqbegin(&monotonic_lock);
+		last_offset = ((unsigned long long)last_cyclone_high<<32)|last_cyclone_low;
+		base = monotonic_base;
+	} while (read_seqretry(&monotonic_lock, seq));
+
+
+	/* Read the cyclone counter */
+	read_cyclone_counter(now_low,now_high);
+	this_offset = ((unsigned long long)now_high<<32)|now_low;
+
+	/* convert to nanoseconds */
+	ret = base + ((this_offset - last_offset)&CYCLONE_TIMER_MASK);
+	return ret * (1000000000 / CYCLONE_TIMER_FREQ);
+}
+
+static int __init init_cyclone(char* override)
+{
+	u32* reg;	
+	u32 base;		/* saved cyclone base address */
+	u32 pageaddr;	/* page that contains cyclone_timer register */
+	u32 offset;		/* offset from pageaddr to cyclone_timer register */
+	int i;
+	
+	/* check clock override */
+	if (override[0] && strncmp(override,"cyclone",7))
+			return -ENODEV;
+
+	/*make sure we're on a summit box*/
+	if(!use_cyclone) return -ENODEV; 
+	
+	printk(KERN_INFO "Summit chipset: Starting Cyclone Counter.\n");
+
+	/* find base address */
+	pageaddr = (CYCLONE_CBAR_ADDR)&PAGE_MASK;
+	offset = (CYCLONE_CBAR_ADDR)&(~PAGE_MASK);
+	set_fixmap_nocache(FIX_CYCLONE_TIMER, pageaddr);
+	reg = (u32*)(fix_to_virt(FIX_CYCLONE_TIMER) + offset);
+	if(!reg){
+		printk(KERN_ERR "Summit chipset: Could not find valid CBAR register.\n");
+		return -ENODEV;
+	}
+	base = *reg;	
+	if(!base){
+		printk(KERN_ERR "Summit chipset: Could not find valid CBAR value.\n");
+		return -ENODEV;
+	}
+	
+	/* setup PMCC */
+	pageaddr = (base + CYCLONE_PMCC_OFFSET)&PAGE_MASK;
+	offset = (base + CYCLONE_PMCC_OFFSET)&(~PAGE_MASK);
+	set_fixmap_nocache(FIX_CYCLONE_TIMER, pageaddr);
+	reg = (u32*)(fix_to_virt(FIX_CYCLONE_TIMER) + offset);
+	if(!reg){
+		printk(KERN_ERR "Summit chipset: Could not find valid PMCC register.\n");
+		return -ENODEV;
+	}
+	reg[0] = 0x00000001;
+
+	/* setup MPCS */
+	pageaddr = (base + CYCLONE_MPCS_OFFSET)&PAGE_MASK;
+	offset = (base + CYCLONE_MPCS_OFFSET)&(~PAGE_MASK);
+	set_fixmap_nocache(FIX_CYCLONE_TIMER, pageaddr);
+	reg = (u32*)(fix_to_virt(FIX_CYCLONE_TIMER) + offset);
+	if(!reg){
+		printk(KERN_ERR "Summit chipset: Could not find valid MPCS register.\n");
+		return -ENODEV;
+	}
+	reg[0] = 0x00000001;
+
+	/* map in cyclone_timer */
+	pageaddr = (base + CYCLONE_MPMC_OFFSET)&PAGE_MASK;
+	offset = (base + CYCLONE_MPMC_OFFSET)&(~PAGE_MASK);
+	set_fixmap_nocache(FIX_CYCLONE_TIMER, pageaddr);
+	cyclone_timer = (u32*)(fix_to_virt(FIX_CYCLONE_TIMER) + offset);
+	if(!cyclone_timer){
+		printk(KERN_ERR "Summit chipset: Could not find valid MPMC register.\n");
+		return -ENODEV;
+	}
+
+	/*quick test to make sure its ticking*/
+	for(i=0; i<3; i++){
+		u32 old = cyclone_timer[0];
+		int stall = 100;
+		while(stall--) barrier();
+		if(cyclone_timer[0] == old){
+			printk(KERN_ERR "Summit chipset: Counter not counting! DISABLED\n");
+			cyclone_timer = 0;
+			return -ENODEV;
+		}
+	}
+
+	init_cpu_khz();
+
+	/* Everything looks good! */
+	return 0;
+}
+
+
+static void delay_cyclone(unsigned long loops)
+{
+	unsigned long bclock, now;
+	if(!cyclone_timer)
+		return;
+	bclock = cyclone_timer[0];
+	do {
+		rep_nop();
+		now = cyclone_timer[0];
+	} while ((now-bclock) < loops);
+}
+/************************************************************/
+
+/* cyclone timer_opts struct */
+static struct timer_opts timer_cyclone = {
+	.name = "cyclone",
+	.mark_offset = mark_offset_cyclone, 
+	.get_offset = get_offset_cyclone,
+	.monotonic_clock =	monotonic_clock_cyclone,
+	.delay = delay_cyclone,
+};
+
+struct init_timer_opts __initdata timer_cyclone_init = {
+	.init = init_cyclone,
+	.opts = &timer_cyclone,
+};