2 * Based on arm clockevents implementation and old bfin time tick.
4 * Copyright 2008-2009 Analog Devics Inc.
8 * Licensed under the GPL-2
11 #include <linux/module.h>
12 #include <linux/profile.h>
13 #include <linux/interrupt.h>
14 #include <linux/time.h>
15 #include <linux/timex.h>
16 #include <linux/irq.h>
17 #include <linux/clocksource.h>
18 #include <linux/clockchips.h>
19 #include <linux/cpufreq.h>
21 #include <asm/blackfin.h>
23 #include <asm/gptimers.h>
27 #if defined(CONFIG_CYCLES_CLOCKSOURCE)
29 static notrace cycle_t bfin_read_cycles(struct clocksource *cs)
31 #ifdef CONFIG_CPU_FREQ
32 return __bfin_cycles_off + (get_cycles() << __bfin_cycles_mod);
38 static struct clocksource bfin_cs_cycles = {
39 .name = "bfin_cs_cycles",
41 .read = bfin_read_cycles,
42 .mask = CLOCKSOURCE_MASK(64),
43 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
46 static inline unsigned long long bfin_cs_cycles_sched_clock(void)
48 return clocksource_cyc2ns(bfin_read_cycles(&bfin_cs_cycles),
49 bfin_cs_cycles.mult, bfin_cs_cycles.shift);
52 static int __init bfin_cs_cycles_init(void)
54 if (clocksource_register_hz(&bfin_cs_cycles, get_cclk()))
55 panic("failed to register clocksource");
60 # define bfin_cs_cycles_init()
63 #ifdef CONFIG_GPTMR0_CLOCKSOURCE
65 void __init setup_gptimer0(void)
67 disable_gptimers(TIMER0bit);
69 set_gptimer_config(TIMER0_id, \
70 TIMER_OUT_DIS | TIMER_PERIOD_CNT | TIMER_MODE_PWM);
71 set_gptimer_period(TIMER0_id, -1);
72 set_gptimer_pwidth(TIMER0_id, -2);
74 enable_gptimers(TIMER0bit);
77 static cycle_t bfin_read_gptimer0(struct clocksource *cs)
79 return bfin_read_TIMER0_COUNTER();
82 static struct clocksource bfin_cs_gptimer0 = {
83 .name = "bfin_cs_gptimer0",
85 .read = bfin_read_gptimer0,
86 .mask = CLOCKSOURCE_MASK(32),
87 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
90 static inline unsigned long long bfin_cs_gptimer0_sched_clock(void)
92 return clocksource_cyc2ns(bfin_read_TIMER0_COUNTER(),
93 bfin_cs_gptimer0.mult, bfin_cs_gptimer0.shift);
96 static int __init bfin_cs_gptimer0_init(void)
100 if (clocksource_register_hz(&bfin_cs_gptimer0, get_sclk()))
101 panic("failed to register clocksource");
106 # define bfin_cs_gptimer0_init()
109 #if defined(CONFIG_GPTMR0_CLOCKSOURCE) || defined(CONFIG_CYCLES_CLOCKSOURCE)
110 /* prefer to use cycles since it has higher rating */
111 notrace unsigned long long sched_clock(void)
113 #if defined(CONFIG_CYCLES_CLOCKSOURCE)
114 return bfin_cs_cycles_sched_clock();
116 return bfin_cs_gptimer0_sched_clock();
121 #if defined(CONFIG_TICKSOURCE_GPTMR0)
122 static int bfin_gptmr0_set_next_event(unsigned long cycles,
123 struct clock_event_device *evt)
125 disable_gptimers(TIMER0bit);
127 /* it starts counting three SCLK cycles after the TIMENx bit is set */
128 set_gptimer_pwidth(TIMER0_id, cycles - 3);
129 enable_gptimers(TIMER0bit);
133 static void bfin_gptmr0_set_mode(enum clock_event_mode mode,
134 struct clock_event_device *evt)
137 case CLOCK_EVT_MODE_PERIODIC: {
138 set_gptimer_config(TIMER0_id, \
139 TIMER_OUT_DIS | TIMER_IRQ_ENA | \
140 TIMER_PERIOD_CNT | TIMER_MODE_PWM);
141 set_gptimer_period(TIMER0_id, get_sclk() / HZ);
142 set_gptimer_pwidth(TIMER0_id, get_sclk() / HZ - 1);
143 enable_gptimers(TIMER0bit);
146 case CLOCK_EVT_MODE_ONESHOT:
147 disable_gptimers(TIMER0bit);
148 set_gptimer_config(TIMER0_id, \
149 TIMER_OUT_DIS | TIMER_IRQ_ENA | TIMER_MODE_PWM);
150 set_gptimer_period(TIMER0_id, 0);
152 case CLOCK_EVT_MODE_UNUSED:
153 case CLOCK_EVT_MODE_SHUTDOWN:
154 disable_gptimers(TIMER0bit);
156 case CLOCK_EVT_MODE_RESUME:
161 static void bfin_gptmr0_ack(void)
163 set_gptimer_status(TIMER_GROUP1, TIMER_STATUS_TIMIL0);
166 static void __init bfin_gptmr0_init(void)
168 disable_gptimers(TIMER0bit);
171 #ifdef CONFIG_CORE_TIMER_IRQ_L1
172 __attribute__((l1_text))
174 irqreturn_t bfin_gptmr0_interrupt(int irq, void *dev_id)
176 struct clock_event_device *evt = dev_id;
178 evt->event_handler(evt);
183 static struct irqaction gptmr0_irq = {
184 .name = "Blackfin GPTimer0",
185 .flags = IRQF_DISABLED | IRQF_TIMER | \
186 IRQF_IRQPOLL | IRQF_PERCPU,
187 .handler = bfin_gptmr0_interrupt,
190 static struct clock_event_device clockevent_gptmr0 = {
191 .name = "bfin_gptimer0",
195 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
196 .set_next_event = bfin_gptmr0_set_next_event,
197 .set_mode = bfin_gptmr0_set_mode,
200 static void __init bfin_gptmr0_clockevent_init(struct clock_event_device *evt)
202 unsigned long clock_tick;
204 clock_tick = get_sclk();
205 evt->mult = div_sc(clock_tick, NSEC_PER_SEC, evt->shift);
206 evt->max_delta_ns = clockevent_delta2ns(-1, evt);
207 evt->min_delta_ns = clockevent_delta2ns(100, evt);
209 evt->cpumask = cpumask_of(0);
211 clockevents_register_device(evt);
213 #endif /* CONFIG_TICKSOURCE_GPTMR0 */
215 #if defined(CONFIG_TICKSOURCE_CORETMR)
216 /* per-cpu local core timer */
217 static DEFINE_PER_CPU(struct clock_event_device, coretmr_events);
219 static int bfin_coretmr_set_next_event(unsigned long cycles,
220 struct clock_event_device *evt)
222 bfin_write_TCNTL(TMPWR);
224 bfin_write_TCOUNT(cycles);
226 bfin_write_TCNTL(TMPWR | TMREN);
230 static void bfin_coretmr_set_mode(enum clock_event_mode mode,
231 struct clock_event_device *evt)
234 case CLOCK_EVT_MODE_PERIODIC: {
235 unsigned long tcount = ((get_cclk() / (HZ * TIME_SCALE)) - 1);
236 bfin_write_TCNTL(TMPWR);
238 bfin_write_TSCALE(TIME_SCALE - 1);
239 bfin_write_TPERIOD(tcount);
240 bfin_write_TCOUNT(tcount);
242 bfin_write_TCNTL(TMPWR | TMREN | TAUTORLD);
245 case CLOCK_EVT_MODE_ONESHOT:
246 bfin_write_TCNTL(TMPWR);
248 bfin_write_TSCALE(TIME_SCALE - 1);
249 bfin_write_TPERIOD(0);
250 bfin_write_TCOUNT(0);
252 case CLOCK_EVT_MODE_UNUSED:
253 case CLOCK_EVT_MODE_SHUTDOWN:
257 case CLOCK_EVT_MODE_RESUME:
262 void bfin_coretmr_init(void)
264 /* power up the timer, but don't enable it just yet */
265 bfin_write_TCNTL(TMPWR);
268 /* the TSCALE prescaler counter. */
269 bfin_write_TSCALE(TIME_SCALE - 1);
270 bfin_write_TPERIOD(0);
271 bfin_write_TCOUNT(0);
276 #ifdef CONFIG_CORE_TIMER_IRQ_L1
277 __attribute__((l1_text))
279 irqreturn_t bfin_coretmr_interrupt(int irq, void *dev_id)
281 int cpu = smp_processor_id();
282 struct clock_event_device *evt = &per_cpu(coretmr_events, cpu);
285 evt->event_handler(evt);
287 touch_nmi_watchdog();
292 static struct irqaction coretmr_irq = {
293 .name = "Blackfin CoreTimer",
294 .flags = IRQF_DISABLED | IRQF_TIMER | \
295 IRQF_IRQPOLL | IRQF_PERCPU,
296 .handler = bfin_coretmr_interrupt,
299 void bfin_coretmr_clockevent_init(void)
301 unsigned long clock_tick;
302 unsigned int cpu = smp_processor_id();
303 struct clock_event_device *evt = &per_cpu(coretmr_events, cpu);
305 evt->name = "bfin_core_timer";
309 evt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
310 evt->set_next_event = bfin_coretmr_set_next_event;
311 evt->set_mode = bfin_coretmr_set_mode;
313 clock_tick = get_cclk() / TIME_SCALE;
314 evt->mult = div_sc(clock_tick, NSEC_PER_SEC, evt->shift);
315 evt->max_delta_ns = clockevent_delta2ns(-1, evt);
316 evt->min_delta_ns = clockevent_delta2ns(100, evt);
318 evt->cpumask = cpumask_of(cpu);
320 clockevents_register_device(evt);
322 #endif /* CONFIG_TICKSOURCE_CORETMR */
325 void read_persistent_clock(struct timespec *ts)
327 time_t secs_since_1970 = (365 * 37 + 9) * 24 * 60 * 60; /* 1 Jan 2007 */
328 ts->tv_sec = secs_since_1970;
332 void __init time_init(void)
335 #ifdef CONFIG_RTC_DRV_BFIN
336 /* [#2663] hack to filter junk RTC values that would cause
337 * userspace to have to deal with time values greater than
338 * 2^31 seconds (which uClibc cannot cope with yet)
340 if ((bfin_read_RTC_STAT() & 0xC0000000) == 0xC0000000) {
341 printk(KERN_NOTICE "bfin-rtc: invalid date; resetting\n");
342 bfin_write_RTC_STAT(0);
346 bfin_cs_cycles_init();
347 bfin_cs_gptimer0_init();
349 #if defined(CONFIG_TICKSOURCE_CORETMR)
351 setup_irq(IRQ_CORETMR, &coretmr_irq);
352 bfin_coretmr_clockevent_init();
355 #if defined(CONFIG_TICKSOURCE_GPTMR0)
357 setup_irq(IRQ_TIMER0, &gptmr0_irq);
358 gptmr0_irq.dev_id = &clockevent_gptmr0;
359 bfin_gptmr0_clockevent_init(&clockevent_gptmr0);
362 #if !defined(CONFIG_TICKSOURCE_CORETMR) && !defined(CONFIG_TICKSOURCE_GPTMR0)
363 # error at least one clock event device is required