2 * linux/arch/arm/mach-omap1/time.c
6 * Copyright (C) 2004 Nokia Corporation
7 * Partial timer rewrite and additional dynamic tick timer support by
8 * Tony Lindgen <tony@atomide.com> and
9 * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
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>
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.
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.
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.
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>
42 #include <linux/clk.h>
43 #include <linux/err.h>
44 #include <linux/clocksource.h>
45 #include <linux/clockchips.h>
48 #include <asm/system.h>
49 #include <mach/hardware.h>
52 #include <asm/mach/irq.h>
53 #include <asm/mach/time.h>
55 #include <plat/common.h>
57 #define OMAP_MPU_TIMER_BASE OMAP_MPU_TIMER1_BASE
58 #define OMAP_MPU_TIMER_OFFSET 0x100
61 u32 cntl
; /* CNTL_TIMER, R/W */
62 u32 load_tim
; /* LOAD_TIM, W */
63 u32 read_tim
; /* READ_TIM, R */
64 } omap_mpu_timer_regs_t
;
66 #define omap_mpu_timer_base(n) \
67 ((volatile omap_mpu_timer_regs_t*)OMAP1_IO_ADDRESS(OMAP_MPU_TIMER_BASE + \
68 (n)*OMAP_MPU_TIMER_OFFSET))
70 static inline unsigned long omap_mpu_timer_read(int nr
)
72 volatile omap_mpu_timer_regs_t
* timer
= omap_mpu_timer_base(nr
);
73 return timer
->read_tim
;
76 static inline void omap_mpu_set_autoreset(int nr
)
78 volatile omap_mpu_timer_regs_t
* timer
= omap_mpu_timer_base(nr
);
80 timer
->cntl
= timer
->cntl
| MPU_TIMER_AR
;
83 static inline void omap_mpu_remove_autoreset(int nr
)
85 volatile omap_mpu_timer_regs_t
* timer
= omap_mpu_timer_base(nr
);
87 timer
->cntl
= timer
->cntl
& ~MPU_TIMER_AR
;
90 static inline void omap_mpu_timer_start(int nr
, unsigned long load_val
,
93 volatile omap_mpu_timer_regs_t
* timer
= omap_mpu_timer_base(nr
);
94 unsigned int timerflags
= (MPU_TIMER_CLOCK_ENABLE
| MPU_TIMER_ST
);
96 if (autoreset
) timerflags
|= MPU_TIMER_AR
;
98 timer
->cntl
= MPU_TIMER_CLOCK_ENABLE
;
100 timer
->load_tim
= load_val
;
102 timer
->cntl
= timerflags
;
105 static inline void omap_mpu_timer_stop(int nr
)
107 volatile omap_mpu_timer_regs_t
* timer
= omap_mpu_timer_base(nr
);
109 timer
->cntl
&= ~MPU_TIMER_ST
;
113 * ---------------------------------------------------------------------------
114 * MPU timer 1 ... count down to zero, interrupt, reload
115 * ---------------------------------------------------------------------------
117 static int omap_mpu_set_next_event(unsigned long cycles
,
118 struct clock_event_device
*evt
)
120 omap_mpu_timer_start(0, cycles
, 0);
124 static void omap_mpu_set_mode(enum clock_event_mode mode
,
125 struct clock_event_device
*evt
)
128 case CLOCK_EVT_MODE_PERIODIC
:
129 omap_mpu_set_autoreset(0);
131 case CLOCK_EVT_MODE_ONESHOT
:
132 omap_mpu_timer_stop(0);
133 omap_mpu_remove_autoreset(0);
135 case CLOCK_EVT_MODE_UNUSED
:
136 case CLOCK_EVT_MODE_SHUTDOWN
:
137 case CLOCK_EVT_MODE_RESUME
:
142 static struct clock_event_device clockevent_mpu_timer1
= {
143 .name
= "mpu_timer1",
144 .features
= CLOCK_EVT_FEAT_PERIODIC
| CLOCK_EVT_FEAT_ONESHOT
,
146 .set_next_event
= omap_mpu_set_next_event
,
147 .set_mode
= omap_mpu_set_mode
,
150 static irqreturn_t
omap_mpu_timer1_interrupt(int irq
, void *dev_id
)
152 struct clock_event_device
*evt
= &clockevent_mpu_timer1
;
154 evt
->event_handler(evt
);
159 static struct irqaction omap_mpu_timer1_irq
= {
160 .name
= "mpu_timer1",
161 .flags
= IRQF_DISABLED
| IRQF_TIMER
| IRQF_IRQPOLL
,
162 .handler
= omap_mpu_timer1_interrupt
,
165 static __init
void omap_init_mpu_timer(unsigned long rate
)
167 setup_irq(INT_TIMER1
, &omap_mpu_timer1_irq
);
168 omap_mpu_timer_start(0, (rate
/ HZ
) - 1, 1);
170 clockevent_mpu_timer1
.mult
= div_sc(rate
, NSEC_PER_SEC
,
171 clockevent_mpu_timer1
.shift
);
172 clockevent_mpu_timer1
.max_delta_ns
=
173 clockevent_delta2ns(-1, &clockevent_mpu_timer1
);
174 clockevent_mpu_timer1
.min_delta_ns
=
175 clockevent_delta2ns(1, &clockevent_mpu_timer1
);
177 clockevent_mpu_timer1
.cpumask
= cpumask_of(0);
178 clockevents_register_device(&clockevent_mpu_timer1
);
183 * ---------------------------------------------------------------------------
184 * MPU timer 2 ... free running 32-bit clock source and scheduler clock
185 * ---------------------------------------------------------------------------
188 static unsigned long omap_mpu_timer2_overflows
;
190 static irqreturn_t
omap_mpu_timer2_interrupt(int irq
, void *dev_id
)
192 omap_mpu_timer2_overflows
++;
196 static struct irqaction omap_mpu_timer2_irq
= {
197 .name
= "mpu_timer2",
198 .flags
= IRQF_DISABLED
,
199 .handler
= omap_mpu_timer2_interrupt
,
202 static cycle_t
mpu_read(struct clocksource
*cs
)
204 return ~omap_mpu_timer_read(1);
207 static struct clocksource clocksource_mpu
= {
208 .name
= "mpu_timer2",
211 .mask
= CLOCKSOURCE_MASK(32),
212 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
215 static void __init
omap_init_clocksource(unsigned long rate
)
217 static char err
[] __initdata
= KERN_ERR
218 "%s: can't register clocksource!\n";
220 setup_irq(INT_TIMER2
, &omap_mpu_timer2_irq
);
221 omap_mpu_timer_start(1, ~0, 1);
223 if (clocksource_register_hz(&clocksource_mpu
, rate
))
224 printk(err
, clocksource_mpu
.name
);
228 * ---------------------------------------------------------------------------
229 * Timer initialization
230 * ---------------------------------------------------------------------------
232 static void __init
omap_timer_init(void)
234 struct clk
*ck_ref
= clk_get(NULL
, "ck_ref");
237 BUG_ON(IS_ERR(ck_ref
));
239 rate
= clk_get_rate(ck_ref
);
245 omap_init_mpu_timer(rate
);
246 omap_init_clocksource(rate
);
249 struct sys_timer omap_timer
= {
250 .init
= omap_timer_init
,