omap1: Fix sched_clock for the MPU timer
[deliverable/linux.git] / arch / arm / mach-omap1 / time.c
CommitLineData
1da177e4 1/*
3b59b6be 2 * linux/arch/arm/mach-omap1/time.c
1da177e4
LT
3 *
4 * OMAP Timers
5 *
6 * Copyright (C) 2004 Nokia Corporation
b3402cf5 7 * Partial timer rewrite and additional dynamic tick timer support by
1da177e4
LT
8 * Tony Lindgen <tony@atomide.com> and
9 * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
10 *
11 * MPU timer code based on the older MPU timer code for OMAP
12 * Copyright (C) 2000 RidgeRun, Inc.
13 * Author: Greg Lonnon <glonnon@ridgerun.com>
14 *
15 * This program is free software; you can redistribute it and/or modify it
16 * under the terms of the GNU General Public License as published by the
17 * Free Software Foundation; either version 2 of the License, or (at your
18 * option) any later version.
19 *
20 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
21 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
22 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
23 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
26 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
27 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * You should have received a copy of the GNU General Public License along
32 * with this program; if not, write to the Free Software Foundation, Inc.,
33 * 675 Mass Ave, Cambridge, MA 02139, USA.
34 */
35
1da177e4
LT
36#include <linux/kernel.h>
37#include <linux/init.h>
38#include <linux/delay.h>
39#include <linux/interrupt.h>
40#include <linux/sched.h>
41#include <linux/spinlock.h>
075192ae
KH
42#include <linux/clk.h>
43#include <linux/err.h>
44#include <linux/clocksource.h>
45#include <linux/clockchips.h>
fced80c7 46#include <linux/io.h>
f376ea17 47#include <linux/sched.h>
1da177e4
LT
48
49#include <asm/system.h>
a09e64fb 50#include <mach/hardware.h>
1da177e4
LT
51#include <asm/leds.h>
52#include <asm/irq.h>
f376ea17
TL
53#include <asm/sched_clock.h>
54
1da177e4
LT
55#include <asm/mach/irq.h>
56#include <asm/mach/time.h>
57
706afdda 58#include <plat/common.h>
1da177e4 59
1da177e4
LT
60#define OMAP_MPU_TIMER_BASE OMAP_MPU_TIMER1_BASE
61#define OMAP_MPU_TIMER_OFFSET 0x100
62
1da177e4
LT
63typedef struct {
64 u32 cntl; /* CNTL_TIMER, R/W */
65 u32 load_tim; /* LOAD_TIM, W */
66 u32 read_tim; /* READ_TIM, R */
67} omap_mpu_timer_regs_t;
68
94113260
TL
69#define omap_mpu_timer_base(n) \
70((volatile omap_mpu_timer_regs_t*)OMAP1_IO_ADDRESS(OMAP_MPU_TIMER_BASE + \
1da177e4
LT
71 (n)*OMAP_MPU_TIMER_OFFSET))
72
f376ea17 73static inline unsigned long notrace omap_mpu_timer_read(int nr)
1da177e4
LT
74{
75 volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
76 return timer->read_tim;
77}
78
075192ae 79static inline void omap_mpu_set_autoreset(int nr)
1da177e4
LT
80{
81 volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
82
075192ae 83 timer->cntl = timer->cntl | MPU_TIMER_AR;
1da177e4
LT
84}
85
075192ae 86static inline void omap_mpu_remove_autoreset(int nr)
1da177e4 87{
075192ae 88 volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
1da177e4 89
075192ae 90 timer->cntl = timer->cntl & ~MPU_TIMER_AR;
1da177e4
LT
91}
92
075192ae
KH
93static inline void omap_mpu_timer_start(int nr, unsigned long load_val,
94 int autoreset)
95{
96 volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
97 unsigned int timerflags = (MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_ST);
98
99 if (autoreset) timerflags |= MPU_TIMER_AR;
100
101 timer->cntl = MPU_TIMER_CLOCK_ENABLE;
102 udelay(1);
103 timer->load_tim = load_val;
104 udelay(1);
105 timer->cntl = timerflags;
106}
1da177e4 107
06cad098
KH
108static inline void omap_mpu_timer_stop(int nr)
109{
110 volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
111
112 timer->cntl &= ~MPU_TIMER_ST;
113}
114
1da177e4 115/*
075192ae
KH
116 * ---------------------------------------------------------------------------
117 * MPU timer 1 ... count down to zero, interrupt, reload
118 * ---------------------------------------------------------------------------
1da177e4 119 */
075192ae 120static int omap_mpu_set_next_event(unsigned long cycles,
06cad098 121 struct clock_event_device *evt)
1da177e4 122{
075192ae
KH
123 omap_mpu_timer_start(0, cycles, 0);
124 return 0;
125}
1da177e4 126
075192ae
KH
127static void omap_mpu_set_mode(enum clock_event_mode mode,
128 struct clock_event_device *evt)
129{
130 switch (mode) {
131 case CLOCK_EVT_MODE_PERIODIC:
132 omap_mpu_set_autoreset(0);
133 break;
134 case CLOCK_EVT_MODE_ONESHOT:
06cad098 135 omap_mpu_timer_stop(0);
075192ae
KH
136 omap_mpu_remove_autoreset(0);
137 break;
138 case CLOCK_EVT_MODE_UNUSED:
139 case CLOCK_EVT_MODE_SHUTDOWN:
18de5bc4 140 case CLOCK_EVT_MODE_RESUME:
075192ae
KH
141 break;
142 }
1da177e4
LT
143}
144
075192ae
KH
145static struct clock_event_device clockevent_mpu_timer1 = {
146 .name = "mpu_timer1",
c6b349ed 147 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
075192ae
KH
148 .shift = 32,
149 .set_next_event = omap_mpu_set_next_event,
150 .set_mode = omap_mpu_set_mode,
151};
152
153static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id)
1da177e4 154{
075192ae 155 struct clock_event_device *evt = &clockevent_mpu_timer1;
1da177e4 156
075192ae 157 evt->event_handler(evt);
1da177e4
LT
158
159 return IRQ_HANDLED;
160}
161
075192ae
KH
162static struct irqaction omap_mpu_timer1_irq = {
163 .name = "mpu_timer1",
b30fabad 164 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
075192ae 165 .handler = omap_mpu_timer1_interrupt,
1da177e4
LT
166};
167
075192ae
KH
168static __init void omap_init_mpu_timer(unsigned long rate)
169{
075192ae
KH
170 setup_irq(INT_TIMER1, &omap_mpu_timer1_irq);
171 omap_mpu_timer_start(0, (rate / HZ) - 1, 1);
172
173 clockevent_mpu_timer1.mult = div_sc(rate, NSEC_PER_SEC,
174 clockevent_mpu_timer1.shift);
175 clockevent_mpu_timer1.max_delta_ns =
176 clockevent_delta2ns(-1, &clockevent_mpu_timer1);
177 clockevent_mpu_timer1.min_delta_ns =
178 clockevent_delta2ns(1, &clockevent_mpu_timer1);
179
320ab2b0 180 clockevent_mpu_timer1.cpumask = cpumask_of(0);
075192ae
KH
181 clockevents_register_device(&clockevent_mpu_timer1);
182}
183
184
185/*
186 * ---------------------------------------------------------------------------
187 * MPU timer 2 ... free running 32-bit clock source and scheduler clock
188 * ---------------------------------------------------------------------------
189 */
190
191static unsigned long omap_mpu_timer2_overflows;
192
193static irqreturn_t omap_mpu_timer2_interrupt(int irq, void *dev_id)
1da177e4 194{
075192ae 195 omap_mpu_timer2_overflows++;
1da177e4
LT
196 return IRQ_HANDLED;
197}
198
075192ae
KH
199static struct irqaction omap_mpu_timer2_irq = {
200 .name = "mpu_timer2",
52e405ea 201 .flags = IRQF_DISABLED,
075192ae 202 .handler = omap_mpu_timer2_interrupt,
1da177e4
LT
203};
204
8e19608e 205static cycle_t mpu_read(struct clocksource *cs)
1da177e4 206{
075192ae
KH
207 return ~omap_mpu_timer_read(1);
208}
209
210static struct clocksource clocksource_mpu = {
211 .name = "mpu_timer2",
212 .rating = 300,
213 .read = mpu_read,
214 .mask = CLOCKSOURCE_MASK(32),
075192ae
KH
215 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
216};
217
f376ea17
TL
218static DEFINE_CLOCK_DATA(cd);
219
220static void notrace mpu_update_sched_clock(void)
221{
222 u32 cyc = mpu_read(&clocksource_mpu);
223 update_sched_clock(&cd, cyc, (u32)~0);
224}
225
075192ae
KH
226static void __init omap_init_clocksource(unsigned long rate)
227{
228 static char err[] __initdata = KERN_ERR
229 "%s: can't register clocksource!\n";
230
075192ae
KH
231 setup_irq(INT_TIMER2, &omap_mpu_timer2_irq);
232 omap_mpu_timer_start(1, ~0, 1);
f376ea17 233 init_sched_clock(&cd, mpu_update_sched_clock, 32, rate);
075192ae 234
8437c25e 235 if (clocksource_register_hz(&clocksource_mpu, rate))
075192ae 236 printk(err, clocksource_mpu.name);
1da177e4
LT
237}
238
1da177e4
LT
239/*
240 * ---------------------------------------------------------------------------
241 * Timer initialization
242 * ---------------------------------------------------------------------------
243 */
3b59b6be 244static void __init omap_timer_init(void)
1da177e4 245{
075192ae
KH
246 struct clk *ck_ref = clk_get(NULL, "ck_ref");
247 unsigned long rate;
248
249 BUG_ON(IS_ERR(ck_ref));
250
251 rate = clk_get_rate(ck_ref);
252 clk_put(ck_ref);
253
254 /* PTV = 0 */
255 rate /= 2;
256
257 omap_init_mpu_timer(rate);
258 omap_init_clocksource(rate);
d8328f3b
PW
259 /*
260 * XXX Since this file seems to deal mostly with the MPU timer,
261 * this doesn't seem like the correct place for the sync timer
262 * clocksource init.
263 */
264 if (!cpu_is_omap7xx() && !cpu_is_omap15xx())
265 omap_init_clocksource_32k();
1da177e4
LT
266}
267
268struct sys_timer omap_timer = {
269 .init = omap_timer_init,
1da177e4 270};
This page took 0.495571 seconds and 5 git commands to generate.