2 * arch/arch/mach-tegra/timer.c
4 * Copyright (C) 2010 Google, Inc.
7 * Colin Cross <ccross@google.com>
9 * This software is licensed under the terms of the GNU General Public
10 * License version 2, as published by the Free Software Foundation, and
11 * may be copied, distributed, and modified under those terms.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
20 #include <linux/init.h>
21 #include <linux/time.h>
22 #include <linux/interrupt.h>
23 #include <linux/irq.h>
24 #include <linux/clockchips.h>
25 #include <linux/clocksource.h>
26 #include <linux/clk.h>
28 #include <linux/cnt32_to_63.h>
30 #include <asm/mach/time.h>
31 #include <asm/mach/time.h>
32 #include <asm/localtimer.h>
34 #include <mach/iomap.h>
35 #include <mach/irqs.h>
36 #include <mach/suspend.h>
42 #define RTC_SECONDS 0x08
43 #define RTC_SHADOW_SECONDS 0x0c
44 #define RTC_MILLISECONDS 0x10
46 #define TIMERUS_CNTR_1US 0x10
47 #define TIMERUS_USEC_CFG 0x14
48 #define TIMERUS_CNTR_FREEZE 0x4c
50 #define TIMER1_BASE 0x0
51 #define TIMER2_BASE 0x8
52 #define TIMER3_BASE 0x50
53 #define TIMER4_BASE 0x58
58 static void __iomem *timer_base = IO_ADDRESS(TEGRA_TMR1_BASE);
59 static void __iomem *rtc_base = IO_ADDRESS(TEGRA_RTC_BASE);
61 #define timer_writel(value, reg) \
62 __raw_writel(value, (u32)timer_base + (reg))
63 #define timer_readl(reg) \
64 __raw_readl((u32)timer_base + (reg))
66 static int tegra_timer_set_next_event(unsigned long cycles,
67 struct clock_event_device *evt)
71 reg = 0x80000000 | ((cycles > 1) ? (cycles-1) : 0);
72 timer_writel(reg, TIMER3_BASE + TIMER_PTV);
77 static void tegra_timer_set_mode(enum clock_event_mode mode,
78 struct clock_event_device *evt)
82 timer_writel(0, TIMER3_BASE + TIMER_PTV);
85 case CLOCK_EVT_MODE_PERIODIC:
86 reg = 0xC0000000 | ((1000000/HZ)-1);
87 timer_writel(reg, TIMER3_BASE + TIMER_PTV);
89 case CLOCK_EVT_MODE_ONESHOT:
91 case CLOCK_EVT_MODE_UNUSED:
92 case CLOCK_EVT_MODE_SHUTDOWN:
93 case CLOCK_EVT_MODE_RESUME:
98 static u64 tegra_us_clocksource_offset;
99 static u64 tegra_us_resume_offset;
100 static cycle_t tegra_clocksource_us_read(struct clocksource *cs)
102 return tegra_us_clocksource_offset +
103 cnt32_to_63(timer_readl(TIMERUS_CNTR_1US));
106 void tegra_clocksource_us_suspend(struct clocksource *cs)
108 tegra_us_resume_offset = tegra_clocksource_us_read(cs) -
109 tegra_rtc_read_ms() * 1000;
112 void tegra_clocksource_us_resume(struct clocksource *cs)
114 tegra_us_clocksource_offset += tegra_us_resume_offset +
115 tegra_rtc_read_ms() * 1000 -
116 tegra_clocksource_us_read(cs);
119 static struct clock_event_device tegra_clockevent = {
122 .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
123 .set_next_event = tegra_timer_set_next_event,
124 .set_mode = tegra_timer_set_mode,
127 static struct clocksource tegra_clocksource_us = {
130 .read = tegra_clocksource_us_read,
131 .suspend= tegra_clocksource_us_suspend,
132 .resume = tegra_clocksource_us_resume,
133 .mask = 0x7FFFFFFFFFFFFFFFULL,
134 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
137 unsigned long long sched_clock(void)
139 return tegra_clocksource_us.read(&tegra_clocksource_us) * 1000;
144 * tegra_rtc_read - Reads the Tegra RTC registers
145 * Care must be taken that this funciton is not called while the
146 * tegra_rtc driver could be executing to avoid race conditions
147 * on the RTC shadow register
149 u64 tegra_rtc_read_ms(void)
151 u32 ms = readl(rtc_base + RTC_MILLISECONDS);
152 u32 s = readl(rtc_base + RTC_SHADOW_SECONDS);
153 return (u64)s * 1000 + ms;
157 * read_persistent_clock - Return time from a persistent clock.
159 * Reads the time from a source which isn't disabled during PM, the
160 * 32k sync timer. Convert the cycles elapsed since last read into
161 * nsecs and adds to a monotonically increasing timespec.
162 * Care must be taken that this funciton is not called while the
163 * tegra_rtc driver could be executing to avoid race conditions
164 * on the RTC shadow register
166 static struct timespec persistent_ts;
167 static u64 persistent_ms, last_persistent_ms;
168 void read_persistent_clock(struct timespec *ts)
171 struct timespec *tsp = &persistent_ts;
173 last_persistent_ms = persistent_ms;
174 persistent_ms = tegra_rtc_read_ms();
175 delta = persistent_ms - last_persistent_ms;
177 timespec_add_ns(tsp, delta * 1000000);
181 static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id)
183 struct clock_event_device *evt = (struct clock_event_device *)dev_id;
184 timer_writel(1<<30, TIMER3_BASE + TIMER_PCR);
185 evt->event_handler(evt);
189 static struct irqaction tegra_timer_irq = {
191 .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_TRIGGER_HIGH,
192 .handler = tegra_timer_interrupt,
193 .dev_id = &tegra_clockevent,
197 static irqreturn_t tegra_lp2wake_interrupt(int irq, void *dev_id)
199 timer_writel(1<<30, TIMER4_BASE + TIMER_PCR);
203 static struct irqaction tegra_lp2wake_irq = {
204 .name = "timer_lp2wake",
205 .flags = IRQF_DISABLED,
206 .handler = tegra_lp2wake_interrupt,
211 static void __init tegra_init_timer(void)
213 unsigned long rate = clk_measure_input_freq();
216 #ifdef CONFIG_HAVE_ARM_TWD
217 twd_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE + 0x600);
222 timer_writel(0x000b, TIMERUS_USEC_CFG);
225 timer_writel(0x000c, TIMERUS_USEC_CFG);
228 timer_writel(0x045f, TIMERUS_USEC_CFG);
231 timer_writel(0x0019, TIMERUS_USEC_CFG);
234 WARN(1, "Unknown clock rate");
237 if (clocksource_register_hz(&tegra_clocksource_us, 1000000)) {
238 printk(KERN_ERR "Failed to register us clocksource\n");
242 ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq);
244 printk(KERN_ERR "Failed to register timer IRQ: %d\n", ret);
248 ret = setup_irq(tegra_lp2wake_irq.irq, &tegra_lp2wake_irq);
250 printk(KERN_ERR "Failed to register LP2 timer IRQ: %d\n", ret);
254 clockevents_calc_mult_shift(&tegra_clockevent, 1000000, 5);
255 tegra_clockevent.max_delta_ns =
256 clockevent_delta2ns(0x1fffffff, &tegra_clockevent);
257 tegra_clockevent.min_delta_ns =
258 clockevent_delta2ns(0x1, &tegra_clockevent);
259 tegra_clockevent.cpumask = cpu_all_mask;
260 tegra_clockevent.irq = tegra_timer_irq.irq;
261 clockevents_register_device(&tegra_clockevent);
266 struct sys_timer tegra_timer = {
267 .init = tegra_init_timer,
270 void tegra_lp2_set_trigger(unsigned long cycles)
272 timer_writel(0, TIMER4_BASE + TIMER_PTV);
274 u32 reg = 0x80000000ul | min(0x1ffffffful, cycles);
275 timer_writel(reg, TIMER4_BASE + TIMER_PTV);
278 EXPORT_SYMBOL(tegra_lp2_set_trigger);
280 unsigned long tegra_lp2_timer_remain(void)
282 return timer_readl(TIMER4_BASE + TIMER_PCR) & 0x1ffffffful;
285 static u32 usec_config;
286 void tegra_timer_suspend(void)
288 usec_config = timer_readl(TIMERUS_USEC_CFG);
291 void tegra_timer_resume(void)
293 timer_writel(usec_config, TIMERUS_USEC_CFG);