1 /*
2 * linux/arch/arm/mach-footbridge/dc21285-timer.c
3 *
4 * Copyright (C) 1998 Russell King.
5 * Copyright (C) 1998 Phil Blundell
6 */
7 #include <linux/clockchips.h>
8 #include <linux/clocksource.h>
9 #include <linux/init.h>
10 #include <linux/interrupt.h>
11 #include <linux/irq.h>
12
13 #include <asm/irq.h>
14
15 #include <asm/hardware/dec21285.h>
16 #include <asm/mach/time.h>
17 #include <asm/system_info.h>
18
19 #include "common.h"
20
cksrc_dc21285_read(struct clocksource * cs)21 static cycle_t cksrc_dc21285_read(struct clocksource *cs)
22 {
23 return cs->mask - *CSR_TIMER2_VALUE;
24 }
25
cksrc_dc21285_enable(struct clocksource * cs)26 static int cksrc_dc21285_enable(struct clocksource *cs)
27 {
28 *CSR_TIMER2_LOAD = cs->mask;
29 *CSR_TIMER2_CLR = 0;
30 *CSR_TIMER2_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_DIV16;
31 return 0;
32 }
33
cksrc_dc21285_disable(struct clocksource * cs)34 static void cksrc_dc21285_disable(struct clocksource *cs)
35 {
36 *CSR_TIMER2_CNTL = 0;
37 }
38
39 static struct clocksource cksrc_dc21285 = {
40 .name = "dc21285_timer2",
41 .rating = 200,
42 .read = cksrc_dc21285_read,
43 .enable = cksrc_dc21285_enable,
44 .disable = cksrc_dc21285_disable,
45 .mask = CLOCKSOURCE_MASK(24),
46 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
47 };
48
ckevt_dc21285_set_mode(enum clock_event_mode mode,struct clock_event_device * c)49 static void ckevt_dc21285_set_mode(enum clock_event_mode mode,
50 struct clock_event_device *c)
51 {
52 switch (mode) {
53 case CLOCK_EVT_MODE_RESUME:
54 case CLOCK_EVT_MODE_PERIODIC:
55 *CSR_TIMER1_CLR = 0;
56 *CSR_TIMER1_LOAD = (mem_fclk_21285 + 8 * HZ) / (16 * HZ);
57 *CSR_TIMER1_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD |
58 TIMER_CNTL_DIV16;
59 break;
60
61 default:
62 *CSR_TIMER1_CNTL = 0;
63 break;
64 }
65 }
66
67 static struct clock_event_device ckevt_dc21285 = {
68 .name = "dc21285_timer1",
69 .features = CLOCK_EVT_FEAT_PERIODIC,
70 .rating = 200,
71 .irq = IRQ_TIMER1,
72 .set_mode = ckevt_dc21285_set_mode,
73 };
74
timer1_interrupt(int irq,void * dev_id)75 static irqreturn_t timer1_interrupt(int irq, void *dev_id)
76 {
77 struct clock_event_device *ce = dev_id;
78
79 *CSR_TIMER1_CLR = 0;
80
81 ce->event_handler(ce);
82
83 return IRQ_HANDLED;
84 }
85
86 static struct irqaction footbridge_timer_irq = {
87 .name = "dc21285_timer1",
88 .handler = timer1_interrupt,
89 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
90 .dev_id = &ckevt_dc21285,
91 };
92
93 /*
94 * Set up timer interrupt.
95 */
footbridge_timer_init(void)96 static void __init footbridge_timer_init(void)
97 {
98 struct clock_event_device *ce = &ckevt_dc21285;
99
100 clocksource_register_hz(&cksrc_dc21285, (mem_fclk_21285 + 8) / 16);
101
102 setup_irq(ce->irq, &footbridge_timer_irq);
103
104 clockevents_calc_mult_shift(ce, mem_fclk_21285, 5);
105 ce->max_delta_ns = clockevent_delta2ns(0xffffff, ce);
106 ce->min_delta_ns = clockevent_delta2ns(0x000004, ce);
107 ce->cpumask = cpumask_of(smp_processor_id());
108
109 clockevents_register_device(ce);
110 }
111
112 struct sys_timer footbridge_timer = {
113 .init = footbridge_timer_init,
114 };
115