1 files changed, 119 insertions, 0 deletions

diff --git a/drivers/clocksource/cyclone.c b/drivers/clocksource/cyclone.c
new file mode 100644
index 000000000000..bf4d3d50d1c4
--- /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);