diff options
Diffstat (limited to 'drivers/sn/ioc4.c')
| -rw-r--r-- | drivers/sn/ioc4.c | 36 |
1 files changed, 17 insertions, 19 deletions
diff --git a/drivers/sn/ioc4.c b/drivers/sn/ioc4.c index 8562821e6498..83d2e90c581c 100644 --- a/drivers/sn/ioc4.c +++ b/drivers/sn/ioc4.c @@ -3,7 +3,7 @@ * License. See the file "COPYING" in the main directory of this archive * for more details. * - * Copyright (C) 2005 Silicon Graphics, Inc. All Rights Reserved. + * Copyright (C) 2005-2006 Silicon Graphics, Inc. All Rights Reserved. */ /* This file contains the master driver module for use by SGI IOC4 subdrivers. @@ -29,9 +29,9 @@ #include <linux/module.h> #include <linux/pci.h> #include <linux/ioc4.h> -#include <linux/mmtimer.h> -#include <linux/rtc.h> +#include <linux/ktime.h> #include <linux/mutex.h> +#include <linux/time.h> #include <asm/sn/addrs.h> #include <asm/sn/clksupport.h> #include <asm/sn/shub_mmr.h> @@ -43,7 +43,7 @@ /* Tweakable values */ /* PCI bus speed detection/calibration */ -#define IOC4_CALIBRATE_COUNT 63 /* Calibration cycle period */ +#define IOC4_CALIBRATE_COUNT 63 /* Calibration cycle period */ #define IOC4_CALIBRATE_CYCLES 256 /* Average over this many cycles */ #define IOC4_CALIBRATE_DISCARD 2 /* Discard first few cycles */ #define IOC4_CALIBRATE_LOW_MHZ 25 /* Lower bound on bus speed sanity */ @@ -143,11 +143,11 @@ ioc4_unregister_submodule(struct ioc4_submodule *is) static void ioc4_clock_calibrate(struct ioc4_driver_data *idd) { - extern unsigned long sn_rtc_cycles_per_second; union ioc4_int_out int_out; union ioc4_gpcr gpcr; unsigned int state, last_state = 1; - uint64_t start = 0, end, period; + struct timespec start_ts, end_ts; + uint64_t start, end, period; unsigned int count = 0; /* Enable output */ @@ -175,30 +175,28 @@ ioc4_clock_calibrate(struct ioc4_driver_data *idd) if (!last_state && state) { count++; if (count == IOC4_CALIBRATE_END) { - end = rtc_time(); + ktime_get_ts(&end_ts); break; } else if (count == IOC4_CALIBRATE_DISCARD) - start = rtc_time(); + ktime_get_ts(&start_ts); } last_state = state; } while (1); /* Calculation rearranged to preserve intermediate precision. * Logically: - * 1. "end - start" gives us number of RTC cycles over all the - * square wave cycles measured. - * 2. Divide by number of square wave cycles to get number of - * RTC cycles per square wave cycle. + * 1. "end - start" gives us the measurement period over all + * the square wave cycles. + * 2. Divide by number of square wave cycles to get the period + * of a square wave cycle. * 3. Divide by 2*(int_out.fields.count+1), which is the formula * by which the IOC4 generates the square wave, to get the - * number of RTC cycles per IOC4 INT_OUT count. - * 4. Divide by sn_rtc_cycles_per_second to get seconds per - * count. - * 5. Multiply by 1E9 to get nanoseconds per count. + * period of an IOC4 INT_OUT count. */ - period = ((end - start) * 1000000000) / - (IOC4_CALIBRATE_CYCLES * 2 * (IOC4_CALIBRATE_COUNT + 1) - * sn_rtc_cycles_per_second); + end = end_ts.tv_sec * NSEC_PER_SEC + end_ts.tv_nsec; + start = start_ts.tv_sec * NSEC_PER_SEC + start_ts.tv_nsec; + period = (end - start) / + (IOC4_CALIBRATE_CYCLES * 2 * (IOC4_CALIBRATE_COUNT + 1)); /* Bounds check the result. */ if (period > IOC4_CALIBRATE_LOW_LIMIT || |