3 * Copyright (C) 2007 Google, Inc.
4 * Copyright (c) 2009-2011, Code Aurora Forum. All rights reserved.
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
17 #include <linux/clocksource.h>
18 #include <linux/clockchips.h>
19 #include <linux/init.h>
20 #include <linux/interrupt.h>
21 #include <linux/irq.h>
24 #include <asm/mach/time.h>
25 #include <asm/hardware/gic.h>
26 #include <asm/localtimer.h>
28 #include <mach/msm_iomap.h>
30 #include <mach/board.h>
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 BIT(1)
36 #define TIMER_ENABLE_EN BIT(0)
37 #define TIMER_CLEAR 0x000C
38 #define DGT_CLK_CTL 0x0034
39 #define DGT_CLK_CTL_DIV_4 0x3
43 /* TODO: Remove these ifdefs */
44 #if defined(CONFIG_ARCH_QSD8X50)
45 #define DGT_HZ (19200000 / 4) /* 19.2 MHz / 4 by default */
46 #define MSM_DGT_SHIFT (0)
47 #elif defined(CONFIG_ARCH_MSM7X30)
48 #define DGT_HZ (24576000 / 4) /* 24.576 MHz (LPXO) / 4 by default */
49 #define MSM_DGT_SHIFT (0)
50 #elif defined(CONFIG_ARCH_MSM8X60) || defined(CONFIG_ARCH_MSM8960)
51 #define DGT_HZ (27000000 / 4) /* 27 MHz (PXO) / 4 by default */
52 #define MSM_DGT_SHIFT (0)
54 #define DGT_HZ 19200000 /* 19.2 MHz or 600 KHz after shift */
55 #define MSM_DGT_SHIFT (5)
58 static void __iomem *event_base;
60 static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
62 struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
63 if (evt->event_handler == NULL)
65 /* Stop the timer tick */
66 if (evt->mode == CLOCK_EVT_MODE_ONESHOT) {
67 u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
68 ctrl &= ~TIMER_ENABLE_EN;
69 writel_relaxed(ctrl, event_base + TIMER_ENABLE);
71 evt->event_handler(evt);
75 static int msm_timer_set_next_event(unsigned long cycles,
76 struct clock_event_device *evt)
78 u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
80 writel_relaxed(0, event_base + TIMER_CLEAR);
81 writel_relaxed(cycles, event_base + TIMER_MATCH_VAL);
82 writel_relaxed(ctrl | TIMER_ENABLE_EN, event_base + TIMER_ENABLE);
86 static void msm_timer_set_mode(enum clock_event_mode mode,
87 struct clock_event_device *evt)
91 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
92 ctrl &= ~(TIMER_ENABLE_EN | TIMER_ENABLE_CLR_ON_MATCH_EN);
95 case CLOCK_EVT_MODE_RESUME:
96 case CLOCK_EVT_MODE_PERIODIC:
98 case CLOCK_EVT_MODE_ONESHOT:
99 /* Timer is enabled in set_next_event */
101 case CLOCK_EVT_MODE_UNUSED:
102 case CLOCK_EVT_MODE_SHUTDOWN:
105 writel_relaxed(ctrl, event_base + TIMER_ENABLE);
108 static struct clock_event_device msm_clockevent = {
110 .features = CLOCK_EVT_FEAT_ONESHOT,
113 .set_next_event = msm_timer_set_next_event,
114 .set_mode = msm_timer_set_mode,
118 struct clock_event_device *evt;
119 struct clock_event_device __percpu **percpu_evt;
122 static void __iomem *source_base;
124 static cycle_t msm_read_timer_count(struct clocksource *cs)
127 * Shift timer count down by a constant due to unreliable lower bits
130 return readl_relaxed(source_base + TIMER_COUNT_VAL) >> MSM_DGT_SHIFT;
133 static struct clocksource msm_clocksource = {
136 .read = msm_read_timer_count,
137 .mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT)),
138 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
141 static void __init msm_timer_init(void)
143 struct clock_event_device *ce = &msm_clockevent;
144 struct clocksource *cs = &msm_clocksource;
147 if (cpu_is_msm7x01()) {
148 event_base = MSM_CSR_BASE;
149 source_base = MSM_CSR_BASE + 0x10;
150 } else if (cpu_is_msm7x30()) {
151 event_base = MSM_CSR_BASE + 0x04;
152 source_base = MSM_CSR_BASE + 0x24;
153 } else if (cpu_is_qsd8x50()) {
154 event_base = MSM_CSR_BASE;
155 source_base = MSM_CSR_BASE + 0x10;
156 } else if (cpu_is_msm8x60() || cpu_is_msm8960()) {
157 event_base = MSM_TMR_BASE + 0x04;
158 /* Use CPU0's timer as the global clock source. */
159 source_base = MSM_TMR0_BASE + 0x24;
163 #ifdef CONFIG_ARCH_MSM_SCORPIONMP
164 writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
167 writel_relaxed(0, event_base + TIMER_ENABLE);
168 writel_relaxed(0, event_base + TIMER_CLEAR);
169 writel_relaxed(~0, event_base + TIMER_MATCH_VAL);
170 ce->mult = div_sc(GPT_HZ, NSEC_PER_SEC, ce->shift);
172 * allow at least 10 seconds to notice that the timer
175 ce->max_delta_ns = clockevent_delta2ns(0xf0000000, ce);
176 /* 4 gets rounded down to 3 */
177 ce->min_delta_ns = clockevent_delta2ns(4, ce);
178 ce->cpumask = cpumask_of(0);
180 ce->irq = INT_GP_TIMER_EXP;
181 if (cpu_is_msm8x60() || cpu_is_msm8960()) {
182 msm_evt.percpu_evt = alloc_percpu(struct clock_event_device *);
183 if (!msm_evt.percpu_evt) {
184 pr_err("memory allocation failed for %s\n", ce->name);
187 *__this_cpu_ptr(msm_evt.percpu_evt) = ce;
188 res = request_percpu_irq(ce->irq, msm_timer_interrupt,
189 ce->name, msm_evt.percpu_evt);
191 enable_percpu_irq(ce->irq, 0);
194 res = request_irq(ce->irq, msm_timer_interrupt,
195 IRQF_TIMER | IRQF_NOBALANCING |
196 IRQF_TRIGGER_RISING, ce->name, &msm_evt.evt);
200 pr_err("request_irq failed for %s\n", ce->name);
201 clockevents_register_device(ce);
203 writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
204 res = clocksource_register_hz(cs, DGT_HZ >> MSM_DGT_SHIFT);
206 pr_err("clocksource_register failed\n");
209 #ifdef CONFIG_LOCAL_TIMERS
210 int __cpuinit local_timer_setup(struct clock_event_device *evt)
212 /* Use existing clock_event for cpu 0 */
213 if (!smp_processor_id())
216 writel_relaxed(0, event_base + TIMER_ENABLE);
217 writel_relaxed(0, event_base + TIMER_CLEAR);
218 writel_relaxed(~0, event_base + TIMER_MATCH_VAL);
219 evt->irq = msm_clockevent.irq;
220 evt->name = "local_timer";
221 evt->features = msm_clockevent.features;
222 evt->rating = msm_clockevent.rating;
223 evt->set_mode = msm_timer_set_mode;
224 evt->set_next_event = msm_timer_set_next_event;
225 evt->shift = msm_clockevent.shift;
226 evt->mult = div_sc(GPT_HZ, NSEC_PER_SEC, evt->shift);
227 evt->max_delta_ns = clockevent_delta2ns(0xf0000000, evt);
228 evt->min_delta_ns = clockevent_delta2ns(4, evt);
230 *__this_cpu_ptr(msm_evt.percpu_evt) = evt;
231 enable_percpu_irq(evt->irq, 0);
232 clockevents_register_device(evt);
236 void local_timer_stop(struct clock_event_device *evt)
238 evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
239 disable_percpu_irq(evt->irq);
241 #endif /* CONFIG_LOCAL_TIMERS */
243 struct sys_timer msm_timer = {
244 .init = msm_timer_init