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[net-next-2.6.git] / arch / arm / mach-msm / timer.c
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1/* linux/arch/arm/mach-msm/timer.c
2 *
3 * Copyright (C) 2007 Google, Inc.
4 *
5 * This software is licensed under the terms of the GNU General Public
6 * License version 2, as published by the Free Software Foundation, and
7 * may be copied, distributed, and modified under those terms.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 */
15
16#include <linux/init.h>
17#include <linux/time.h>
18#include <linux/interrupt.h>
19#include <linux/irq.h>
20#include <linux/clk.h>
21#include <linux/clockchips.h>
22#include <linux/delay.h>
fced80c7 23#include <linux/io.h>
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24
25#include <asm/mach/time.h>
a09e64fb 26#include <mach/msm_iomap.h>
3e4ea372 27
83a2c0e4 28#ifndef MSM_DGT_BASE
3e4ea372 29#define MSM_DGT_BASE (MSM_GPT_BASE + 0x10)
83a2c0e4 30#endif
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31
32#define TIMER_MATCH_VAL 0x0000
33#define TIMER_COUNT_VAL 0x0004
34#define TIMER_ENABLE 0x0008
35#define TIMER_ENABLE_CLR_ON_MATCH_EN 2
36#define TIMER_ENABLE_EN 1
37#define TIMER_CLEAR 0x000C
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38#define DGT_CLK_CTL 0x0034
39enum {
40 DGT_CLK_CTL_DIV_1 = 0,
41 DGT_CLK_CTL_DIV_2 = 1,
42 DGT_CLK_CTL_DIV_3 = 2,
43 DGT_CLK_CTL_DIV_4 = 3,
44};
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45#define CSR_PROTECTION 0x0020
46#define CSR_PROTECTION_EN 1
47
48#define GPT_HZ 32768
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49
50#if defined(CONFIG_ARCH_QSD8X50)
51#define DGT_HZ (19200000 / 4) /* 19.2 MHz / 4 by default */
52#define MSM_DGT_SHIFT (0)
53#elif defined(CONFIG_ARCH_MSM7X30) || defined(CONFIG_ARCH_MSM8X60)
54#define DGT_HZ (24576000 / 4) /* 24.576 MHz (LPXO) / 4 by default */
55#define MSM_DGT_SHIFT (0)
56#else
3e4ea372 57#define DGT_HZ 19200000 /* 19.2 MHz or 600 KHz after shift */
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58#define MSM_DGT_SHIFT (5)
59#endif
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60
61struct msm_clock {
62 struct clock_event_device clockevent;
63 struct clocksource clocksource;
64 struct irqaction irq;
bcc0f6af 65 void __iomem *regbase;
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66 uint32_t freq;
67 uint32_t shift;
68};
69
70static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
71{
72 struct clock_event_device *evt = dev_id;
73 evt->event_handler(evt);
74 return IRQ_HANDLED;
75}
76
8e19608e 77static cycle_t msm_gpt_read(struct clocksource *cs)
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78{
79 return readl(MSM_GPT_BASE + TIMER_COUNT_VAL);
80}
81
8e19608e 82static cycle_t msm_dgt_read(struct clocksource *cs)
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83{
84 return readl(MSM_DGT_BASE + TIMER_COUNT_VAL) >> MSM_DGT_SHIFT;
85}
86
87static int msm_timer_set_next_event(unsigned long cycles,
88 struct clock_event_device *evt)
89{
90 struct msm_clock *clock = container_of(evt, struct msm_clock, clockevent);
91 uint32_t now = readl(clock->regbase + TIMER_COUNT_VAL);
92 uint32_t alarm = now + (cycles << clock->shift);
93 int late;
94
95 writel(alarm, clock->regbase + TIMER_MATCH_VAL);
96 now = readl(clock->regbase + TIMER_COUNT_VAL);
97 late = now - alarm;
98 if (late >= (-2 << clock->shift) && late < DGT_HZ*5) {
99 printk(KERN_NOTICE "msm_timer_set_next_event(%lu) clock %s, "
100 "alarm already expired, now %x, alarm %x, late %d\n",
101 cycles, clock->clockevent.name, now, alarm, late);
102 return -ETIME;
103 }
104 return 0;
105}
106
107static void msm_timer_set_mode(enum clock_event_mode mode,
108 struct clock_event_device *evt)
109{
110 struct msm_clock *clock = container_of(evt, struct msm_clock, clockevent);
111 switch (mode) {
112 case CLOCK_EVT_MODE_RESUME:
113 case CLOCK_EVT_MODE_PERIODIC:
114 break;
115 case CLOCK_EVT_MODE_ONESHOT:
116 writel(TIMER_ENABLE_EN, clock->regbase + TIMER_ENABLE);
117 break;
118 case CLOCK_EVT_MODE_UNUSED:
119 case CLOCK_EVT_MODE_SHUTDOWN:
120 writel(0, clock->regbase + TIMER_ENABLE);
121 break;
122 }
123}
124
125static struct msm_clock msm_clocks[] = {
126 {
127 .clockevent = {
128 .name = "gp_timer",
129 .features = CLOCK_EVT_FEAT_ONESHOT,
130 .shift = 32,
131 .rating = 200,
132 .set_next_event = msm_timer_set_next_event,
133 .set_mode = msm_timer_set_mode,
134 },
135 .clocksource = {
136 .name = "gp_timer",
137 .rating = 200,
138 .read = msm_gpt_read,
139 .mask = CLOCKSOURCE_MASK(32),
6f941961 140 .shift = 17,
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141 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
142 },
143 .irq = {
144 .name = "gp_timer",
145 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_TRIGGER_RISING,
146 .handler = msm_timer_interrupt,
147 .dev_id = &msm_clocks[0].clockevent,
148 .irq = INT_GP_TIMER_EXP
149 },
150 .regbase = MSM_GPT_BASE,
151 .freq = GPT_HZ
152 },
153 {
154 .clockevent = {
155 .name = "dg_timer",
156 .features = CLOCK_EVT_FEAT_ONESHOT,
157 .shift = 32 + MSM_DGT_SHIFT,
158 .rating = 300,
159 .set_next_event = msm_timer_set_next_event,
160 .set_mode = msm_timer_set_mode,
161 },
162 .clocksource = {
163 .name = "dg_timer",
164 .rating = 300,
165 .read = msm_dgt_read,
166 .mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT)),
167 .shift = 24 - MSM_DGT_SHIFT,
168 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
169 },
170 .irq = {
171 .name = "dg_timer",
172 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_TRIGGER_RISING,
173 .handler = msm_timer_interrupt,
174 .dev_id = &msm_clocks[1].clockevent,
175 .irq = INT_DEBUG_TIMER_EXP
176 },
177 .regbase = MSM_DGT_BASE,
178 .freq = DGT_HZ >> MSM_DGT_SHIFT,
179 .shift = MSM_DGT_SHIFT
180 }
181};
182
183static void __init msm_timer_init(void)
184{
185 int i;
186 int res;
187
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188#ifdef CONFIG_ARCH_MSM8X60
189 writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
190#endif
191
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192 for (i = 0; i < ARRAY_SIZE(msm_clocks); i++) {
193 struct msm_clock *clock = &msm_clocks[i];
194 struct clock_event_device *ce = &clock->clockevent;
195 struct clocksource *cs = &clock->clocksource;
196 writel(0, clock->regbase + TIMER_ENABLE);
197 writel(0, clock->regbase + TIMER_CLEAR);
198 writel(~0, clock->regbase + TIMER_MATCH_VAL);
199
200 ce->mult = div_sc(clock->freq, NSEC_PER_SEC, ce->shift);
201 /* allow at least 10 seconds to notice that the timer wrapped */
202 ce->max_delta_ns =
203 clockevent_delta2ns(0xf0000000 >> clock->shift, ce);
204 /* 4 gets rounded down to 3 */
205 ce->min_delta_ns = clockevent_delta2ns(4, ce);
320ab2b0 206 ce->cpumask = cpumask_of(0);
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207
208 cs->mult = clocksource_hz2mult(clock->freq, cs->shift);
209 res = clocksource_register(cs);
210 if (res)
211 printk(KERN_ERR "msm_timer_init: clocksource_register "
212 "failed for %s\n", cs->name);
213
214 res = setup_irq(clock->irq.irq, &clock->irq);
215 if (res)
216 printk(KERN_ERR "msm_timer_init: setup_irq "
217 "failed for %s\n", cs->name);
218
219 clockevents_register_device(ce);
220 }
221}
222
223struct sys_timer msm_timer = {
224 .init = msm_timer_init
225};