1 files changed, 119 insertions, 0 deletions
diff --git a/drivers/clocksource/cyclone.c b/drivers/clocksource/cyclone.c
new file mode 100644
index 00000000000..bf4d3d50d1c
--- /dev/null
+++ b/drivers/clocksource/cyclone.c
@@ -0,0 +1,119 @@
+#include <linux/clocksource.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/timex.h>
+#include <linux/init.h>
+
+#include <asm/pgtable.h>
+#include <asm/io.h>
+
+#include "mach_timer.h"
+
+#define CYCLONE_CBAR_ADDR	0xFEB00CD0	/* base address ptr */
+#define CYCLONE_PMCC_OFFSET	0x51A0		/* offset to control register */
+#define CYCLONE_MPCS_OFFSET	0x51A8		/* offset to select register */
+#define CYCLONE_MPMC_OFFSET	0x51D0		/* offset to count register */
+#define CYCLONE_TIMER_FREQ	99780000	/* 100Mhz, but not really */
+#define CYCLONE_TIMER_MASK	CLOCKSOURCE_MASK(32) /* 32 bit mask */
+
+int use_cyclone = 0;
+static void __iomem *cyclone_ptr;
+
+static cycle_t read_cyclone(void)
+{
+	return (cycle_t)readl(cyclone_ptr);
+}
+
+static struct clocksource clocksource_cyclone = {
+	.name		= "cyclone",
+	.rating		= 250,
+	.read		= read_cyclone,
+	.mask		= CYCLONE_TIMER_MASK,
+	.mult		= 10,
+	.shift		= 0,
+	.is_continuous	= 1,
+};
+
+static int __init init_cyclone_clocksource(void)
+{
+	unsigned long base;	/* saved value from CBAR */
+	unsigned long offset;
+	u32 __iomem* volatile cyclone_timer;	/* Cyclone MPMC0 register */
+	u32 __iomem* reg;
+	int i;
+
+	/* 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: */
+	offset = CYCLONE_CBAR_ADDR;
+	reg = ioremap_nocache(offset, sizeof(reg));
+	if (!reg) {
+		printk(KERN_ERR "Summit chipset: Could not find valid CBAR register.\n");
+		return -ENODEV;
+	}
+	/* even on 64bit systems, this is only 32bits: */
+	base = readl(reg);
+	if (!base) {
+		printk(KERN_ERR "Summit chipset: Could not find valid CBAR value.\n");
+		return -ENODEV;
+	}
+	iounmap(reg);
+
+	/* setup PMCC: */
+	offset = base + CYCLONE_PMCC_OFFSET;
+	reg = ioremap_nocache(offset, sizeof(reg));
+	if (!reg) {
+		printk(KERN_ERR "Summit chipset: Could not find valid PMCC register.\n");
+		return -ENODEV;
+	}
+	writel(0x00000001,reg);
+	iounmap(reg);
+
+	/* setup MPCS: */
+	offset = base + CYCLONE_MPCS_OFFSET;
+	reg = ioremap_nocache(offset, sizeof(reg));
+	if (!reg) {
+		printk(KERN_ERR "Summit chipset: Could not find valid MPCS register.\n");
+		return -ENODEV;
+	}
+	writel(0x00000001,reg);
+	iounmap(reg);
+
+	/* map in cyclone_timer: */
+	offset = base + CYCLONE_MPMC_OFFSET;
+	cyclone_timer = ioremap_nocache(offset, sizeof(u64));
+	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 = readl(cyclone_timer);
+		int stall = 100;
+
+		while (stall--)
+			barrier();
+
+		if (readl(cyclone_timer) == old) {
+			printk(KERN_ERR "Summit chipset: Counter not counting! DISABLED\n");
+			iounmap(cyclone_timer);
+			cyclone_timer = NULL;
+			return -ENODEV;
+		}
+	}
+	cyclone_ptr = cyclone_timer;
+
+	/* sort out mult/shift values: */
+	clocksource_cyclone.shift = 22;
+	clocksource_cyclone.mult = clocksource_hz2mult(CYCLONE_TIMER_FREQ,
+						clocksource_cyclone.shift);
+
+	return clocksource_register(&clocksource_cyclone);
+}
+
+module_init(init_cyclone_clocksource);