GNU Linux-libre 4.4.295-gnu1
[releases.git] / arch / arm / mach-omap1 / time.c
1 /*
2  * linux/arch/arm/mach-omap1/time.c
3  *
4  * OMAP Timers
5  *
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>
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
36 #include <linux/kernel.h>
37 #include <linux/init.h>
38 #include <linux/delay.h>
39 #include <linux/interrupt.h>
40 #include <linux/spinlock.h>
41 #include <linux/clk.h>
42 #include <linux/err.h>
43 #include <linux/clocksource.h>
44 #include <linux/clockchips.h>
45 #include <linux/io.h>
46 #include <linux/sched_clock.h>
47
48 #include <asm/irq.h>
49
50 #include <mach/hardware.h>
51 #include <asm/mach/irq.h>
52 #include <asm/mach/time.h>
53
54 #include "iomap.h"
55 #include "common.h"
56
57 #ifdef CONFIG_OMAP_MPU_TIMER
58
59 #define OMAP_MPU_TIMER_BASE             OMAP_MPU_TIMER1_BASE
60 #define OMAP_MPU_TIMER_OFFSET           0x100
61
62 typedef struct {
63         u32 cntl;                       /* CNTL_TIMER, R/W */
64         u32 load_tim;                   /* LOAD_TIM,   W */
65         u32 read_tim;                   /* READ_TIM,   R */
66 } omap_mpu_timer_regs_t;
67
68 #define omap_mpu_timer_base(n)                                                  \
69 ((omap_mpu_timer_regs_t __iomem *)OMAP1_IO_ADDRESS(OMAP_MPU_TIMER_BASE +        \
70                                  (n)*OMAP_MPU_TIMER_OFFSET))
71
72 static inline unsigned long notrace omap_mpu_timer_read(int nr)
73 {
74         omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
75         return readl(&timer->read_tim);
76 }
77
78 static inline void omap_mpu_set_autoreset(int nr)
79 {
80         omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
81
82         writel(readl(&timer->cntl) | MPU_TIMER_AR, &timer->cntl);
83 }
84
85 static inline void omap_mpu_remove_autoreset(int nr)
86 {
87         omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
88
89         writel(readl(&timer->cntl) & ~MPU_TIMER_AR, &timer->cntl);
90 }
91
92 static inline void omap_mpu_timer_start(int nr, unsigned long load_val,
93                                         int autoreset)
94 {
95         omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
96         unsigned int timerflags = MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_ST;
97
98         if (autoreset)
99                 timerflags |= MPU_TIMER_AR;
100
101         writel(MPU_TIMER_CLOCK_ENABLE, &timer->cntl);
102         udelay(1);
103         writel(load_val, &timer->load_tim);
104         udelay(1);
105         writel(timerflags, &timer->cntl);
106 }
107
108 static inline void omap_mpu_timer_stop(int nr)
109 {
110         omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(nr);
111
112         writel(readl(&timer->cntl) & ~MPU_TIMER_ST, &timer->cntl);
113 }
114
115 /*
116  * ---------------------------------------------------------------------------
117  * MPU timer 1 ... count down to zero, interrupt, reload
118  * ---------------------------------------------------------------------------
119  */
120 static int omap_mpu_set_next_event(unsigned long cycles,
121                                    struct clock_event_device *evt)
122 {
123         omap_mpu_timer_start(0, cycles, 0);
124         return 0;
125 }
126
127 static int omap_mpu_set_oneshot(struct clock_event_device *evt)
128 {
129         omap_mpu_timer_stop(0);
130         omap_mpu_remove_autoreset(0);
131         return 0;
132 }
133
134 static int omap_mpu_set_periodic(struct clock_event_device *evt)
135 {
136         omap_mpu_set_autoreset(0);
137         return 0;
138 }
139
140 static struct clock_event_device clockevent_mpu_timer1 = {
141         .name                   = "mpu_timer1",
142         .features               = CLOCK_EVT_FEAT_PERIODIC |
143                                   CLOCK_EVT_FEAT_ONESHOT,
144         .set_next_event         = omap_mpu_set_next_event,
145         .set_state_periodic     = omap_mpu_set_periodic,
146         .set_state_oneshot      = omap_mpu_set_oneshot,
147 };
148
149 static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id)
150 {
151         struct clock_event_device *evt = &clockevent_mpu_timer1;
152
153         evt->event_handler(evt);
154
155         return IRQ_HANDLED;
156 }
157
158 static struct irqaction omap_mpu_timer1_irq = {
159         .name           = "mpu_timer1",
160         .flags          = IRQF_TIMER | IRQF_IRQPOLL,
161         .handler        = omap_mpu_timer1_interrupt,
162 };
163
164 static __init void omap_init_mpu_timer(unsigned long rate)
165 {
166         setup_irq(INT_TIMER1, &omap_mpu_timer1_irq);
167         omap_mpu_timer_start(0, (rate / HZ) - 1, 1);
168
169         clockevent_mpu_timer1.cpumask = cpumask_of(0);
170         clockevents_config_and_register(&clockevent_mpu_timer1, rate,
171                                         1, -1);
172 }
173
174
175 /*
176  * ---------------------------------------------------------------------------
177  * MPU timer 2 ... free running 32-bit clock source and scheduler clock
178  * ---------------------------------------------------------------------------
179  */
180
181 static u64 notrace omap_mpu_read_sched_clock(void)
182 {
183         return ~omap_mpu_timer_read(1);
184 }
185
186 static void __init omap_init_clocksource(unsigned long rate)
187 {
188         omap_mpu_timer_regs_t __iomem *timer = omap_mpu_timer_base(1);
189         static char err[] __initdata = KERN_ERR
190                         "%s: can't register clocksource!\n";
191
192         omap_mpu_timer_start(1, ~0, 1);
193         sched_clock_register(omap_mpu_read_sched_clock, 32, rate);
194
195         if (clocksource_mmio_init(&timer->read_tim, "mpu_timer2", rate,
196                         300, 32, clocksource_mmio_readl_down))
197                 printk(err, "mpu_timer2");
198 }
199
200 static void __init omap_mpu_timer_init(void)
201 {
202         struct clk      *ck_ref = clk_get(NULL, "ck_ref");
203         unsigned long   rate;
204
205         BUG_ON(IS_ERR(ck_ref));
206
207         rate = clk_get_rate(ck_ref);
208         clk_put(ck_ref);
209
210         /* PTV = 0 */
211         rate /= 2;
212
213         omap_init_mpu_timer(rate);
214         omap_init_clocksource(rate);
215 }
216
217 #else
218 static inline void omap_mpu_timer_init(void)
219 {
220         pr_err("Bogus timer, should not happen\n");
221 }
222 #endif  /* CONFIG_OMAP_MPU_TIMER */
223
224 /*
225  * ---------------------------------------------------------------------------
226  * Timer initialization
227  * ---------------------------------------------------------------------------
228  */
229 void __init omap1_timer_init(void)
230 {
231         if (omap_32k_timer_init() != 0)
232                 omap_mpu_timer_init();
233 }