2 * DaVinci timer subsystem
4 * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
6 * 2007 (c) MontaVista Software, Inc. This file is licensed under
7 * the terms of the GNU General Public License version 2. This program
8 * is licensed "as is" without any warranty of any kind, whether express
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/types.h>
14 #include <linux/interrupt.h>
15 #include <linux/clocksource.h>
16 #include <linux/clockchips.h>
17 #include <linux/spinlock.h>
19 #include <linux/clk.h>
20 #include <linux/err.h>
21 #include <linux/device.h>
22 #include <linux/platform_device.h>
24 #include <mach/hardware.h>
25 #include <asm/system.h>
27 #include <asm/mach/irq.h>
28 #include <asm/mach/time.h>
29 #include <asm/errno.h>
31 #include <mach/cputype.h>
34 static struct clock_event_device clockevent_davinci;
35 static unsigned int davinci_clock_tick_rate;
37 #define DAVINCI_TIMER0_BASE (IO_PHYS + 0x21400)
38 #define DAVINCI_TIMER1_BASE (IO_PHYS + 0x21800)
39 #define DAVINCI_WDOG_BASE (IO_PHYS + 0x21C00)
42 T0_BOT = 0, T0_TOP, T1_BOT, T1_TOP, NUM_TIMERS,
45 #define IS_TIMER1(id) (id & 0x2)
46 #define IS_TIMER0(id) (!IS_TIMER1(id))
47 #define IS_TIMER_TOP(id) ((id & 0x1))
48 #define IS_TIMER_BOT(id) (!IS_TIMER_TOP(id))
50 static int timer_irqs[NUM_TIMERS] = {
58 * This driver configures the 2 64-bit count-up timers as 4 independent
59 * 32-bit count-up timers used as follows:
61 * T0_BOT: Timer 0, bottom: clockevent source for hrtimers
62 * T0_TOP: Timer 0, top : clocksource for generic timekeeping
63 * T1_BOT: Timer 1, bottom: (used by DSP in TI DSPLink code)
64 * T1_TOP: Timer 1, top : <unused>
66 #define TID_CLOCKEVENT T0_BOT
67 #define TID_CLOCKSOURCE T0_TOP
69 /* Timer register offsets */
79 /* Timer register bitfields */
80 #define TCR_ENAMODE_DISABLE 0x0
81 #define TCR_ENAMODE_ONESHOT 0x1
82 #define TCR_ENAMODE_PERIODIC 0x2
83 #define TCR_ENAMODE_MASK 0x3
85 #define TGCR_TIMMODE_SHIFT 2
86 #define TGCR_TIMMODE_64BIT_GP 0x0
87 #define TGCR_TIMMODE_32BIT_UNCHAINED 0x1
88 #define TGCR_TIMMODE_64BIT_WDOG 0x2
89 #define TGCR_TIMMODE_32BIT_CHAINED 0x3
91 #define TGCR_TIM12RS_SHIFT 0
92 #define TGCR_TIM34RS_SHIFT 1
93 #define TGCR_RESET 0x0
94 #define TGCR_UNRESET 0x1
95 #define TGCR_RESET_MASK 0x3
97 #define WDTCR_WDEN_SHIFT 14
98 #define WDTCR_WDEN_DISABLE 0x0
99 #define WDTCR_WDEN_ENABLE 0x1
100 #define WDTCR_WDKEY_SHIFT 16
101 #define WDTCR_WDKEY_SEQ0 0xa5c6
102 #define WDTCR_WDKEY_SEQ1 0xda7e
107 unsigned long period;
110 unsigned long tim_off;
111 unsigned long prd_off;
112 unsigned long enamode_shift;
113 struct irqaction irqaction;
115 static struct timer_s timers[];
117 /* values for 'opts' field of struct timer_s */
118 #define TIMER_OPTS_DISABLED 0x00
119 #define TIMER_OPTS_ONESHOT 0x01
120 #define TIMER_OPTS_PERIODIC 0x02
122 static int timer32_config(struct timer_s *t)
124 u32 tcr = __raw_readl(t->base + TCR);
127 tcr &= ~(TCR_ENAMODE_MASK << t->enamode_shift);
128 __raw_writel(tcr, t->base + TCR);
130 /* reset counter to zero, set new period */
131 __raw_writel(0, t->base + t->tim_off);
132 __raw_writel(t->period, t->base + t->prd_off);
134 /* Set enable mode */
135 if (t->opts & TIMER_OPTS_ONESHOT) {
136 tcr |= TCR_ENAMODE_ONESHOT << t->enamode_shift;
137 } else if (t->opts & TIMER_OPTS_PERIODIC) {
138 tcr |= TCR_ENAMODE_PERIODIC << t->enamode_shift;
141 __raw_writel(tcr, t->base + TCR);
145 static inline u32 timer32_read(struct timer_s *t)
147 return __raw_readl(t->base + t->tim_off);
150 static irqreturn_t timer_interrupt(int irq, void *dev_id)
152 struct clock_event_device *evt = &clockevent_davinci;
154 evt->event_handler(evt);
158 /* called when 32-bit counter wraps */
159 static irqreturn_t freerun_interrupt(int irq, void *dev_id)
164 static struct timer_s timers[] = {
166 .name = "clockevent",
167 .opts = TIMER_OPTS_DISABLED,
169 .flags = IRQF_DISABLED | IRQF_TIMER,
170 .handler = timer_interrupt,
173 [TID_CLOCKSOURCE] = {
174 .name = "free-run counter",
176 .opts = TIMER_OPTS_PERIODIC,
178 .flags = IRQF_DISABLED | IRQF_TIMER,
179 .handler = freerun_interrupt,
184 static void __init timer_init(void)
186 u32 phys_bases[] = {DAVINCI_TIMER0_BASE, DAVINCI_TIMER1_BASE};
189 /* Global init of each 64-bit timer as a whole */
192 void __iomem *base = IO_ADDRESS(phys_bases[i]);
194 /* Disabled, Internal clock source */
195 __raw_writel(0, base + TCR);
197 /* reset both timers, no pre-scaler for timer34 */
199 __raw_writel(tgcr, base + TGCR);
201 /* Set both timers to unchained 32-bit */
202 tgcr = TGCR_TIMMODE_32BIT_UNCHAINED << TGCR_TIMMODE_SHIFT;
203 __raw_writel(tgcr, base + TGCR);
206 tgcr |= (TGCR_UNRESET << TGCR_TIM12RS_SHIFT) |
207 (TGCR_UNRESET << TGCR_TIM34RS_SHIFT);
208 __raw_writel(tgcr, base + TGCR);
210 /* Init both counters to zero */
211 __raw_writel(0, base + TIM12);
212 __raw_writel(0, base + TIM34);
215 /* Init of each timer as a 32-bit timer */
216 for (i=0; i< ARRAY_SIZE(timers); i++) {
217 struct timer_s *t = &timers[i];
222 phys_base = (IS_TIMER1(t->id) ?
223 DAVINCI_TIMER1_BASE : DAVINCI_TIMER0_BASE);
224 t->base = IO_ADDRESS(phys_base);
226 if (IS_TIMER_BOT(t->id)) {
227 t->enamode_shift = 6;
231 t->enamode_shift = 22;
236 /* Register interrupt */
237 t->irqaction.name = t->name;
238 t->irqaction.dev_id = (void *)t;
239 if (t->irqaction.handler != NULL) {
240 setup_irq(timer_irqs[t->id], &t->irqaction);
243 timer32_config(&timers[i]);
251 static cycle_t read_cycles(struct clocksource *cs)
253 struct timer_s *t = &timers[TID_CLOCKSOURCE];
255 return (cycles_t)timer32_read(t);
258 static struct clocksource clocksource_davinci = {
262 .mask = CLOCKSOURCE_MASK(32),
264 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
270 static int davinci_set_next_event(unsigned long cycles,
271 struct clock_event_device *evt)
273 struct timer_s *t = &timers[TID_CLOCKEVENT];
280 static void davinci_set_mode(enum clock_event_mode mode,
281 struct clock_event_device *evt)
283 struct timer_s *t = &timers[TID_CLOCKEVENT];
286 case CLOCK_EVT_MODE_PERIODIC:
287 t->period = davinci_clock_tick_rate / (HZ);
288 t->opts = TIMER_OPTS_PERIODIC;
291 case CLOCK_EVT_MODE_ONESHOT:
292 t->opts = TIMER_OPTS_ONESHOT;
294 case CLOCK_EVT_MODE_UNUSED:
295 case CLOCK_EVT_MODE_SHUTDOWN:
296 t->opts = TIMER_OPTS_DISABLED;
298 case CLOCK_EVT_MODE_RESUME:
303 static struct clock_event_device clockevent_davinci = {
305 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
307 .set_next_event = davinci_set_next_event,
308 .set_mode = davinci_set_mode,
312 static void __init davinci_timer_init(void)
314 struct clk *timer_clk;
316 static char err[] __initdata = KERN_ERR
317 "%s: can't register clocksource!\n";
322 timer_clk = clk_get(NULL, "timer0");
323 BUG_ON(IS_ERR(timer_clk));
324 clk_enable(timer_clk);
326 davinci_clock_tick_rate = clk_get_rate(timer_clk);
328 /* setup clocksource */
329 clocksource_davinci.mult =
330 clocksource_khz2mult(davinci_clock_tick_rate/1000,
331 clocksource_davinci.shift);
332 if (clocksource_register(&clocksource_davinci))
333 printk(err, clocksource_davinci.name);
335 /* setup clockevent */
336 clockevent_davinci.mult = div_sc(davinci_clock_tick_rate, NSEC_PER_SEC,
337 clockevent_davinci.shift);
338 clockevent_davinci.max_delta_ns =
339 clockevent_delta2ns(0xfffffffe, &clockevent_davinci);
340 clockevent_davinci.min_delta_ns =
341 clockevent_delta2ns(1, &clockevent_davinci);
343 clockevent_davinci.cpumask = cpumask_of(0);
344 clockevents_register_device(&clockevent_davinci);
347 struct sys_timer davinci_timer = {
348 .init = davinci_timer_init,
352 /* reset board using watchdog timer */
353 void davinci_watchdog_reset(void)
356 void __iomem *base = IO_ADDRESS(DAVINCI_WDOG_BASE);
359 wd_clk = clk_get(&davinci_wdt_device.dev, NULL);
360 if (WARN_ON(IS_ERR(wd_clk)))
364 /* disable, internal clock source */
365 __raw_writel(0, base + TCR);
367 /* reset timer, set mode to 64-bit watchdog, and unreset */
369 __raw_writel(tgcr, base + TCR);
370 tgcr = TGCR_TIMMODE_64BIT_WDOG << TGCR_TIMMODE_SHIFT;
371 tgcr |= (TGCR_UNRESET << TGCR_TIM12RS_SHIFT) |
372 (TGCR_UNRESET << TGCR_TIM34RS_SHIFT);
373 __raw_writel(tgcr, base + TCR);
375 /* clear counter and period regs */
376 __raw_writel(0, base + TIM12);
377 __raw_writel(0, base + TIM34);
378 __raw_writel(0, base + PRD12);
379 __raw_writel(0, base + PRD34);
382 wdtcr = __raw_readl(base + WDTCR);
383 wdtcr |= WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT;
384 __raw_writel(wdtcr, base + WDTCR);
386 /* put watchdog in pre-active state */
387 wdtcr = (WDTCR_WDKEY_SEQ0 << WDTCR_WDKEY_SHIFT) |
388 (WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT);
389 __raw_writel(wdtcr, base + WDTCR);
391 /* put watchdog in active state */
392 wdtcr = (WDTCR_WDKEY_SEQ1 << WDTCR_WDKEY_SHIFT) |
393 (WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT);
394 __raw_writel(wdtcr, base + WDTCR);
396 /* write an invalid value to the WDKEY field to trigger
397 * a watchdog reset */
399 __raw_writel(wdtcr, base + WDTCR);