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 @@ | |||
3 | * License. See the file "COPYING" in the main directory of this archive | 3 | * License. See the file "COPYING" in the main directory of this archive |
4 | * for more details. | 4 | * for more details. |
5 | * | 5 | * |
6 | * Copyright (C) 2005 Silicon Graphics, Inc. All Rights Reserved. | 6 | * Copyright (C) 2005-2006 Silicon Graphics, Inc. All Rights Reserved. |
7 | */ | 7 | */ |
8 | 8 | ||
9 | /* This file contains the master driver module for use by SGI IOC4 subdrivers. | 9 | /* This file contains the master driver module for use by SGI IOC4 subdrivers. |
@@ -29,9 +29,9 @@ | |||
29 | #include <linux/module.h> | 29 | #include <linux/module.h> |
30 | #include <linux/pci.h> | 30 | #include <linux/pci.h> |
31 | #include <linux/ioc4.h> | 31 | #include <linux/ioc4.h> |
32 | #include <linux/mmtimer.h> | 32 | #include <linux/ktime.h> |
33 | #include <linux/rtc.h> | ||
34 | #include <linux/mutex.h> | 33 | #include <linux/mutex.h> |
34 | #include <linux/time.h> | ||
35 | #include <asm/sn/addrs.h> | 35 | #include <asm/sn/addrs.h> |
36 | #include <asm/sn/clksupport.h> | 36 | #include <asm/sn/clksupport.h> |
37 | #include <asm/sn/shub_mmr.h> | 37 | #include <asm/sn/shub_mmr.h> |
@@ -43,7 +43,7 @@ | |||
43 | /* Tweakable values */ | 43 | /* Tweakable values */ |
44 | 44 | ||
45 | /* PCI bus speed detection/calibration */ | 45 | /* PCI bus speed detection/calibration */ |
46 | #define IOC4_CALIBRATE_COUNT 63 /* Calibration cycle period */ | 46 | #define IOC4_CALIBRATE_COUNT 63 /* Calibration cycle period */ |
47 | #define IOC4_CALIBRATE_CYCLES 256 /* Average over this many cycles */ | 47 | #define IOC4_CALIBRATE_CYCLES 256 /* Average over this many cycles */ |
48 | #define IOC4_CALIBRATE_DISCARD 2 /* Discard first few cycles */ | 48 | #define IOC4_CALIBRATE_DISCARD 2 /* Discard first few cycles */ |
49 | #define IOC4_CALIBRATE_LOW_MHZ 25 /* Lower bound on bus speed sanity */ | 49 | #define IOC4_CALIBRATE_LOW_MHZ 25 /* Lower bound on bus speed sanity */ |
@@ -143,11 +143,11 @@ ioc4_unregister_submodule(struct ioc4_submodule *is) | |||
143 | static void | 143 | static void |
144 | ioc4_clock_calibrate(struct ioc4_driver_data *idd) | 144 | ioc4_clock_calibrate(struct ioc4_driver_data *idd) |
145 | { | 145 | { |
146 | extern unsigned long sn_rtc_cycles_per_second; | ||
147 | union ioc4_int_out int_out; | 146 | union ioc4_int_out int_out; |
148 | union ioc4_gpcr gpcr; | 147 | union ioc4_gpcr gpcr; |
149 | unsigned int state, last_state = 1; | 148 | unsigned int state, last_state = 1; |
150 | uint64_t start = 0, end, period; | 149 | struct timespec start_ts, end_ts; |
150 | uint64_t start, end, period; | ||
151 | unsigned int count = 0; | 151 | unsigned int count = 0; |
152 | 152 | ||
153 | /* Enable output */ | 153 | /* Enable output */ |
@@ -175,30 +175,28 @@ ioc4_clock_calibrate(struct ioc4_driver_data *idd) | |||
175 | if (!last_state && state) { | 175 | if (!last_state && state) { |
176 | count++; | 176 | count++; |
177 | if (count == IOC4_CALIBRATE_END) { | 177 | if (count == IOC4_CALIBRATE_END) { |
178 | end = rtc_time(); | 178 | ktime_get_ts(&end_ts); |
179 | break; | 179 | break; |
180 | } else if (count == IOC4_CALIBRATE_DISCARD) | 180 | } else if (count == IOC4_CALIBRATE_DISCARD) |
181 | start = rtc_time(); | 181 | ktime_get_ts(&start_ts); |
182 | } | 182 | } |
183 | last_state = state; | 183 | last_state = state; |
184 | } while (1); | 184 | } while (1); |
185 | 185 | ||
186 | /* Calculation rearranged to preserve intermediate precision. | 186 | /* Calculation rearranged to preserve intermediate precision. |
187 | * Logically: | 187 | * Logically: |
188 | * 1. "end - start" gives us number of RTC cycles over all the | 188 | * 1. "end - start" gives us the measurement period over all |
189 | * square wave cycles measured. | 189 | * the square wave cycles. |
190 | * 2. Divide by number of square wave cycles to get number of | 190 | * 2. Divide by number of square wave cycles to get the period |
191 | * RTC cycles per square wave cycle. | 191 | * of a square wave cycle. |
192 | * 3. Divide by 2*(int_out.fields.count+1), which is the formula | 192 | * 3. Divide by 2*(int_out.fields.count+1), which is the formula |
193 | * by which the IOC4 generates the square wave, to get the | 193 | * by which the IOC4 generates the square wave, to get the |
194 | * number of RTC cycles per IOC4 INT_OUT count. | 194 | * period of an IOC4 INT_OUT count. |
195 | * 4. Divide by sn_rtc_cycles_per_second to get seconds per | ||
196 | * count. | ||
197 | * 5. Multiply by 1E9 to get nanoseconds per count. | ||
198 | */ | 195 | */ |
199 | period = ((end - start) * 1000000000) / | 196 | end = end_ts.tv_sec * NSEC_PER_SEC + end_ts.tv_nsec; |
200 | (IOC4_CALIBRATE_CYCLES * 2 * (IOC4_CALIBRATE_COUNT + 1) | 197 | start = start_ts.tv_sec * NSEC_PER_SEC + start_ts.tv_nsec; |
201 | * sn_rtc_cycles_per_second); | 198 | period = (end - start) / |
199 | (IOC4_CALIBRATE_CYCLES * 2 * (IOC4_CALIBRATE_COUNT + 1)); | ||
202 | 200 | ||
203 | /* Bounds check the result. */ | 201 | /* Bounds check the result. */ |
204 | if (period > IOC4_CALIBRATE_LOW_LIMIT || | 202 | if (period > IOC4_CALIBRATE_LOW_LIMIT || |