1 /*
2 * GT641xx clockevent routines.
3 *
4 * Copyright (C) 2007 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20 #include <linux/clockchips.h>
21 #include <linux/init.h>
22 #include <linux/interrupt.h>
23 #include <linux/spinlock.h>
24
25 #include <asm/gt64120.h>
26 #include <asm/time.h>
27
28 static DEFINE_SPINLOCK(gt641xx_timer_lock);
29 static unsigned int gt641xx_base_clock;
30
gt641xx_set_base_clock(unsigned int clock)31 void gt641xx_set_base_clock(unsigned int clock)
32 {
33 gt641xx_base_clock = clock;
34 }
35
gt641xx_timer0_state(void)36 int gt641xx_timer0_state(void)
37 {
38 if (GT_READ(GT_TC0_OFS))
39 return 0;
40
41 GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
42 GT_WRITE(GT_TC_CONTROL_OFS, GT_TC_CONTROL_ENTC0_MSK);
43
44 return 1;
45 }
46
gt641xx_timer0_set_next_event(unsigned long delta,struct clock_event_device * evt)47 static int gt641xx_timer0_set_next_event(unsigned long delta,
48 struct clock_event_device *evt)
49 {
50 u32 ctrl;
51
52 spin_lock(>641xx_timer_lock);
53
54 ctrl = GT_READ(GT_TC_CONTROL_OFS);
55 ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
56 ctrl |= GT_TC_CONTROL_ENTC0_MSK;
57
58 GT_WRITE(GT_TC0_OFS, delta);
59 GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
60
61 spin_unlock(>641xx_timer_lock);
62
63 return 0;
64 }
65
gt641xx_timer0_set_mode(enum clock_event_mode mode,struct clock_event_device * evt)66 static void gt641xx_timer0_set_mode(enum clock_event_mode mode,
67 struct clock_event_device *evt)
68 {
69 u32 ctrl;
70
71 spin_lock(>641xx_timer_lock);
72
73 ctrl = GT_READ(GT_TC_CONTROL_OFS);
74 ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
75
76 switch (mode) {
77 case CLOCK_EVT_MODE_PERIODIC:
78 ctrl |= GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK;
79 break;
80 case CLOCK_EVT_MODE_ONESHOT:
81 ctrl |= GT_TC_CONTROL_ENTC0_MSK;
82 break;
83 default:
84 break;
85 }
86
87 GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
88
89 spin_unlock(>641xx_timer_lock);
90 }
91
gt641xx_timer0_event_handler(struct clock_event_device * dev)92 static void gt641xx_timer0_event_handler(struct clock_event_device *dev)
93 {
94 }
95
96 static struct clock_event_device gt641xx_timer0_clockevent = {
97 .name = "gt641xx-timer0",
98 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
99 .irq = GT641XX_TIMER0_IRQ,
100 .set_next_event = gt641xx_timer0_set_next_event,
101 .set_mode = gt641xx_timer0_set_mode,
102 .event_handler = gt641xx_timer0_event_handler,
103 };
104
gt641xx_timer0_interrupt(int irq,void * dev_id)105 static irqreturn_t gt641xx_timer0_interrupt(int irq, void *dev_id)
106 {
107 struct clock_event_device *cd = >641xx_timer0_clockevent;
108
109 cd->event_handler(cd);
110
111 return IRQ_HANDLED;
112 }
113
114 static struct irqaction gt641xx_timer0_irqaction = {
115 .handler = gt641xx_timer0_interrupt,
116 .flags = IRQF_DISABLED | IRQF_PERCPU,
117 .name = "gt641xx_timer0",
118 };
119
gt641xx_timer0_clockevent_init(void)120 static int __init gt641xx_timer0_clockevent_init(void)
121 {
122 struct clock_event_device *cd;
123
124 if (!gt641xx_base_clock)
125 return 0;
126
127 GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
128
129 cd = >641xx_timer0_clockevent;
130 cd->rating = 200 + gt641xx_base_clock / 10000000;
131 clockevent_set_clock(cd, gt641xx_base_clock);
132 cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
133 cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
134 cd->cpumask = cpumask_of(0);
135
136 clockevents_register_device(>641xx_timer0_clockevent);
137
138 return setup_irq(GT641XX_TIMER0_IRQ, >641xx_timer0_irqaction);
139 }
140 arch_initcall(gt641xx_timer0_clockevent_init);
141