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>
23 #include <mach/hardware.h>
24 #include <asm/system.h>
26 #include <asm/mach/irq.h>
27 #include <asm/mach/time.h>
28 #include <asm/errno.h>
30 #include <mach/cputype.h>
33 static struct clock_event_device clockevent_davinci;
35 #define DAVINCI_TIMER0_BASE (IO_PHYS + 0x21400)
36 #define DAVINCI_TIMER1_BASE (IO_PHYS + 0x21800)
37 #define DAVINCI_WDOG_BASE (IO_PHYS + 0x21C00)
40 T0_BOT = 0, T0_TOP, T1_BOT, T1_TOP, NUM_TIMERS,
43 #define IS_TIMER1(id) (id & 0x2)
44 #define IS_TIMER0(id) (!IS_TIMER1(id))
45 #define IS_TIMER_TOP(id) ((id & 0x1))
46 #define IS_TIMER_BOT(id) (!IS_TIMER_TOP(id))
48 static int timer_irqs[NUM_TIMERS] = {
56 * This driver configures the 2 64-bit count-up timers as 4 independent
57 * 32-bit count-up timers used as follows:
59 * T0_BOT: Timer 0, bottom: clockevent source for hrtimers
60 * T0_TOP: Timer 0, top : clocksource for generic timekeeping
61 * T1_BOT: Timer 1, bottom: (used by DSP in TI DSPLink code)
62 * T1_TOP: Timer 1, top : <unused>
64 #define TID_CLOCKEVENT T0_BOT
65 #define TID_CLOCKSOURCE T0_TOP
67 /* Timer register offsets */
77 /* Timer register bitfields */
78 #define TCR_ENAMODE_DISABLE 0x0
79 #define TCR_ENAMODE_ONESHOT 0x1
80 #define TCR_ENAMODE_PERIODIC 0x2
81 #define TCR_ENAMODE_MASK 0x3
83 #define TGCR_TIMMODE_SHIFT 2
84 #define TGCR_TIMMODE_64BIT_GP 0x0
85 #define TGCR_TIMMODE_32BIT_UNCHAINED 0x1
86 #define TGCR_TIMMODE_64BIT_WDOG 0x2
87 #define TGCR_TIMMODE_32BIT_CHAINED 0x3
89 #define TGCR_TIM12RS_SHIFT 0
90 #define TGCR_TIM34RS_SHIFT 1
91 #define TGCR_RESET 0x0
92 #define TGCR_UNRESET 0x1
93 #define TGCR_RESET_MASK 0x3
95 #define WDTCR_WDEN_SHIFT 14
96 #define WDTCR_WDEN_DISABLE 0x0
97 #define WDTCR_WDEN_ENABLE 0x1
98 #define WDTCR_WDKEY_SHIFT 16
99 #define WDTCR_WDKEY_SEQ0 0xa5c6
100 #define WDTCR_WDKEY_SEQ1 0xda7e
105 unsigned long period;
108 unsigned long tim_off;
109 unsigned long prd_off;
110 unsigned long enamode_shift;
111 struct irqaction irqaction;
113 static struct timer_s timers[];
115 /* values for 'opts' field of struct timer_s */
116 #define TIMER_OPTS_DISABLED 0x00
117 #define TIMER_OPTS_ONESHOT 0x01
118 #define TIMER_OPTS_PERIODIC 0x02
120 static int timer32_config(struct timer_s *t)
122 u32 tcr = __raw_readl(t->base + TCR);
125 tcr &= ~(TCR_ENAMODE_MASK << t->enamode_shift);
126 __raw_writel(tcr, t->base + TCR);
128 /* reset counter to zero, set new period */
129 __raw_writel(0, t->base + t->tim_off);
130 __raw_writel(t->period, t->base + t->prd_off);
132 /* Set enable mode */
133 if (t->opts & TIMER_OPTS_ONESHOT) {
134 tcr |= TCR_ENAMODE_ONESHOT << t->enamode_shift;
135 } else if (t->opts & TIMER_OPTS_PERIODIC) {
136 tcr |= TCR_ENAMODE_PERIODIC << t->enamode_shift;
139 __raw_writel(tcr, t->base + TCR);
143 static inline u32 timer32_read(struct timer_s *t)
145 return __raw_readl(t->base + t->tim_off);
148 static irqreturn_t timer_interrupt(int irq, void *dev_id)
150 struct clock_event_device *evt = &clockevent_davinci;
152 evt->event_handler(evt);
156 /* called when 32-bit counter wraps */
157 static irqreturn_t freerun_interrupt(int irq, void *dev_id)
162 static struct timer_s timers[] = {
164 .name = "clockevent",
165 .opts = TIMER_OPTS_DISABLED,
167 .flags = IRQF_DISABLED | IRQF_TIMER,
168 .handler = timer_interrupt,
171 [TID_CLOCKSOURCE] = {
172 .name = "free-run counter",
174 .opts = TIMER_OPTS_PERIODIC,
176 .flags = IRQF_DISABLED | IRQF_TIMER,
177 .handler = freerun_interrupt,
182 static void __init timer_init(void)
184 u32 phys_bases[] = {DAVINCI_TIMER0_BASE, DAVINCI_TIMER1_BASE};
187 /* Global init of each 64-bit timer as a whole */
190 void __iomem *base = IO_ADDRESS(phys_bases[i]);
192 /* Disabled, Internal clock source */
193 __raw_writel(0, base + TCR);
195 /* reset both timers, no pre-scaler for timer34 */
197 __raw_writel(tgcr, base + TGCR);
199 /* Set both timers to unchained 32-bit */
200 tgcr = TGCR_TIMMODE_32BIT_UNCHAINED << TGCR_TIMMODE_SHIFT;
201 __raw_writel(tgcr, base + TGCR);
204 tgcr |= (TGCR_UNRESET << TGCR_TIM12RS_SHIFT) |
205 (TGCR_UNRESET << TGCR_TIM34RS_SHIFT);
206 __raw_writel(tgcr, base + TGCR);
208 /* Init both counters to zero */
209 __raw_writel(0, base + TIM12);
210 __raw_writel(0, base + TIM34);
213 /* Init of each timer as a 32-bit timer */
214 for (i=0; i< ARRAY_SIZE(timers); i++) {
215 struct timer_s *t = &timers[i];
220 phys_base = (IS_TIMER1(t->id) ?
221 DAVINCI_TIMER1_BASE : DAVINCI_TIMER0_BASE);
222 t->base = IO_ADDRESS(phys_base);
224 if (IS_TIMER_BOT(t->id)) {
225 t->enamode_shift = 6;
229 t->enamode_shift = 22;
234 /* Register interrupt */
235 t->irqaction.name = t->name;
236 t->irqaction.dev_id = (void *)t;
237 if (t->irqaction.handler != NULL) {
238 setup_irq(timer_irqs[t->id], &t->irqaction);
241 timer32_config(&timers[i]);
249 static cycle_t read_cycles(struct clocksource *cs)
251 struct timer_s *t = &timers[TID_CLOCKSOURCE];
253 return (cycles_t)timer32_read(t);
256 static struct clocksource clocksource_davinci = {
260 .mask = CLOCKSOURCE_MASK(32),
262 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
268 static int davinci_set_next_event(unsigned long cycles,
269 struct clock_event_device *evt)
271 struct timer_s *t = &timers[TID_CLOCKEVENT];
278 static void davinci_set_mode(enum clock_event_mode mode,
279 struct clock_event_device *evt)
281 struct timer_s *t = &timers[TID_CLOCKEVENT];
284 case CLOCK_EVT_MODE_PERIODIC:
285 t->period = CLOCK_TICK_RATE / (HZ);
286 t->opts = TIMER_OPTS_PERIODIC;
289 case CLOCK_EVT_MODE_ONESHOT:
290 t->opts = TIMER_OPTS_ONESHOT;
292 case CLOCK_EVT_MODE_UNUSED:
293 case CLOCK_EVT_MODE_SHUTDOWN:
294 t->opts = TIMER_OPTS_DISABLED;
296 case CLOCK_EVT_MODE_RESUME:
301 static struct clock_event_device clockevent_davinci = {
303 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
305 .set_next_event = davinci_set_next_event,
306 .set_mode = davinci_set_mode,
310 static void __init davinci_timer_init(void)
312 static char err[] __initdata = KERN_ERR
313 "%s: can't register clocksource!\n";
318 /* setup clocksource */
319 clocksource_davinci.mult =
320 clocksource_khz2mult(CLOCK_TICK_RATE/1000,
321 clocksource_davinci.shift);
322 if (clocksource_register(&clocksource_davinci))
323 printk(err, clocksource_davinci.name);
325 /* setup clockevent */
326 clockevent_davinci.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC,
327 clockevent_davinci.shift);
328 clockevent_davinci.max_delta_ns =
329 clockevent_delta2ns(0xfffffffe, &clockevent_davinci);
330 clockevent_davinci.min_delta_ns =
331 clockevent_delta2ns(1, &clockevent_davinci);
333 clockevent_davinci.cpumask = cpumask_of(0);
334 clockevents_register_device(&clockevent_davinci);
337 struct sys_timer davinci_timer = {
338 .init = davinci_timer_init,
342 /* reset board using watchdog timer */
343 void davinci_watchdog_reset(void) {
345 void __iomem *base = IO_ADDRESS(DAVINCI_WDOG_BASE);
347 /* disable, internal clock source */
348 __raw_writel(0, base + TCR);
350 /* reset timer, set mode to 64-bit watchdog, and unreset */
352 __raw_writel(tgcr, base + TCR);
353 tgcr = TGCR_TIMMODE_64BIT_WDOG << TGCR_TIMMODE_SHIFT;
354 tgcr |= (TGCR_UNRESET << TGCR_TIM12RS_SHIFT) |
355 (TGCR_UNRESET << TGCR_TIM34RS_SHIFT);
356 __raw_writel(tgcr, base + TCR);
358 /* clear counter and period regs */
359 __raw_writel(0, base + TIM12);
360 __raw_writel(0, base + TIM34);
361 __raw_writel(0, base + PRD12);
362 __raw_writel(0, base + PRD34);
365 wdtcr = __raw_readl(base + WDTCR);
366 wdtcr |= WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT;
367 __raw_writel(wdtcr, base + WDTCR);
369 /* put watchdog in pre-active state */
370 wdtcr = (WDTCR_WDKEY_SEQ0 << WDTCR_WDKEY_SHIFT) |
371 (WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT);
372 __raw_writel(wdtcr, base + WDTCR);
374 /* put watchdog in active state */
375 wdtcr = (WDTCR_WDKEY_SEQ1 << WDTCR_WDKEY_SHIFT) |
376 (WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT);
377 __raw_writel(wdtcr, base + WDTCR);
379 /* write an invalid value to the WDKEY field to trigger
380 * a watchdog reset */
382 __raw_writel(wdtcr, base + WDTCR);