* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
#include <asm/system.h>
#include <asm/hardware.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
-struct sys_timer omap_timer;
-#ifdef CONFIG_OMAP_MPU_TIMER
-
-/*
- * ---------------------------------------------------------------------------
- * MPU timer
- * ---------------------------------------------------------------------------
- */
#define OMAP_MPU_TIMER_BASE OMAP_MPU_TIMER1_BASE
#define OMAP_MPU_TIMER_OFFSET 0x100
return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
}
-/*
- * MPU_TICKS_PER_SEC must be an even number, otherwise machinecycles_to_usecs
- * will break. On P2, the timer count rate is 6.5 MHz after programming PTV
- * with 0. This divides the 13MHz input by 2, and is undocumented.
- */
-#ifdef CONFIG_MACH_OMAP_PERSEUS2
-/* REVISIT: This ifdef construct should be replaced by a query to clock
- * framework to see if timer base frequency is 12.0, 13.0 or 19.2 MHz.
- */
-#define MPU_TICKS_PER_SEC (13000000 / 2)
-#else
-#define MPU_TICKS_PER_SEC (12000000 / 2)
-#endif
-
-#define MPU_TIMER_TICK_PERIOD ((MPU_TICKS_PER_SEC / HZ) - 1)
typedef struct {
u32 cntl; /* CNTL_TIMER, R/W */
return timer->read_tim;
}
-static inline void omap_mpu_timer_start(int nr, unsigned long load_val)
+static inline void omap_mpu_set_autoreset(int nr)
{
volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
- timer->cntl = MPU_TIMER_CLOCK_ENABLE;
- udelay(1);
- timer->load_tim = load_val;
- udelay(1);
- timer->cntl = (MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_AR | MPU_TIMER_ST);
+ timer->cntl = timer->cntl | MPU_TIMER_AR;
}
-unsigned long omap_mpu_timer_ticks_to_usecs(unsigned long nr_ticks)
+static inline void omap_mpu_remove_autoreset(int nr)
{
- unsigned long long nsec;
+ volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
- nsec = cycles_2_ns((unsigned long long)nr_ticks);
- return (unsigned long)nsec / 1000;
+ timer->cntl = timer->cntl & ~MPU_TIMER_AR;
}
-/*
- * Last processed system timer interrupt
- */
-static unsigned long omap_mpu_timer_last = 0;
-
-/*
- * Returns elapsed usecs since last system timer interrupt
- */
-static unsigned long omap_mpu_timer_gettimeoffset(void)
+static inline void omap_mpu_timer_start(int nr, unsigned long load_val,
+ int autoreset)
{
- unsigned long now = 0 - omap_mpu_timer_read(0);
- unsigned long elapsed = now - omap_mpu_timer_last;
+ volatile omap_mpu_timer_regs_t* timer = omap_mpu_timer_base(nr);
+ unsigned int timerflags = (MPU_TIMER_CLOCK_ENABLE | MPU_TIMER_ST);
+
+ if (autoreset) timerflags |= MPU_TIMER_AR;
- return omap_mpu_timer_ticks_to_usecs(elapsed);
+ timer->cntl = MPU_TIMER_CLOCK_ENABLE;
+ udelay(1);
+ timer->load_tim = load_val;
+ udelay(1);
+ timer->cntl = timerflags;
}
/*
- * Elapsed time between interrupts is calculated using timer0.
- * Latency during the interrupt is calculated using timer1.
- * Both timer0 and timer1 are counting at 6MHz (P2 6.5MHz).
+ * ---------------------------------------------------------------------------
+ * MPU timer 1 ... count down to zero, interrupt, reload
+ * ---------------------------------------------------------------------------
*/
-static irqreturn_t omap_mpu_timer_interrupt(int irq, void *dev_id,
- struct pt_regs *regs)
+static int omap_mpu_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
{
- unsigned long now, latency;
-
- write_seqlock(&xtime_lock);
- now = 0 - omap_mpu_timer_read(0);
- latency = MPU_TICKS_PER_SEC / HZ - omap_mpu_timer_read(1);
- omap_mpu_timer_last = now - latency;
- timer_tick(regs);
- write_sequnlock(&xtime_lock);
+ omap_mpu_timer_start(0, cycles, 0);
+ return 0;
+}
- return IRQ_HANDLED;
+static void omap_mpu_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ omap_mpu_set_autoreset(0);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ omap_mpu_remove_autoreset(0);
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+ }
}
-static struct irqaction omap_mpu_timer_irq = {
- .name = "mpu timer",
- .flags = SA_INTERRUPT | SA_TIMER,
- .handler = omap_mpu_timer_interrupt,
+static struct clock_event_device clockevent_mpu_timer1 = {
+ .name = "mpu_timer1",
+ .features = CLOCK_EVT_FEAT_PERIODIC, CLOCK_EVT_FEAT_ONESHOT,
+ .shift = 32,
+ .set_next_event = omap_mpu_set_next_event,
+ .set_mode = omap_mpu_set_mode,
};
-static unsigned long omap_mpu_timer1_overflows;
-static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id,
- struct pt_regs *regs)
+static irqreturn_t omap_mpu_timer1_interrupt(int irq, void *dev_id)
{
- omap_mpu_timer1_overflows++;
+ struct clock_event_device *evt = &clockevent_mpu_timer1;
+
+ evt->event_handler(evt);
+
return IRQ_HANDLED;
}
static struct irqaction omap_mpu_timer1_irq = {
- .name = "mpu timer1 overflow",
- .flags = SA_INTERRUPT,
+ .name = "mpu_timer1",
+ .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = omap_mpu_timer1_interrupt,
};
-static __init void omap_init_mpu_timer(void)
+static __init void omap_init_mpu_timer(unsigned long rate)
{
- set_cyc2ns_scale(MPU_TICKS_PER_SEC / 1000);
- omap_timer.offset = omap_mpu_timer_gettimeoffset;
+ set_cyc2ns_scale(rate / 1000);
+
setup_irq(INT_TIMER1, &omap_mpu_timer1_irq);
- setup_irq(INT_TIMER2, &omap_mpu_timer_irq);
- omap_mpu_timer_start(0, 0xffffffff);
- omap_mpu_timer_start(1, MPU_TIMER_TICK_PERIOD);
-}
+ omap_mpu_timer_start(0, (rate / HZ) - 1, 1);
-/*
- * Scheduler clock - returns current time in nanosec units.
- */
-unsigned long long sched_clock(void)
-{
- unsigned long ticks = 0 - omap_mpu_timer_read(0);
- unsigned long long ticks64;
+ clockevent_mpu_timer1.mult = div_sc(rate, NSEC_PER_SEC,
+ clockevent_mpu_timer1.shift);
+ clockevent_mpu_timer1.max_delta_ns =
+ clockevent_delta2ns(-1, &clockevent_mpu_timer1);
+ clockevent_mpu_timer1.min_delta_ns =
+ clockevent_delta2ns(1, &clockevent_mpu_timer1);
- ticks64 = omap_mpu_timer1_overflows;
- ticks64 <<= 32;
- ticks64 |= ticks;
-
- return cycles_2_ns(ticks64);
+ clockevent_mpu_timer1.cpumask = cpumask_of_cpu(0);
+ clockevents_register_device(&clockevent_mpu_timer1);
}
-#endif /* CONFIG_OMAP_MPU_TIMER */
-#ifdef CONFIG_OMAP_32K_TIMER
-
-#ifdef CONFIG_ARCH_OMAP1510
-#error OMAP 32KHz timer does not currently work on 1510!
-#endif
/*
* ---------------------------------------------------------------------------
- * 32KHz OS timer
- *
- * This currently works only on 16xx, as 1510 does not have the continuous
- * 32KHz synchronous timer. The 32KHz synchronous timer is used to keep track
- * of time in addition to the 32KHz OS timer. Using only the 32KHz OS timer
- * on 1510 would be possible, but the timer would not be as accurate as
- * with the 32KHz synchronized timer.
+ * MPU timer 2 ... free running 32-bit clock source and scheduler clock
* ---------------------------------------------------------------------------
*/
-#define OMAP_32K_TIMER_BASE 0xfffb9000
-#define OMAP_32K_TIMER_CR 0x08
-#define OMAP_32K_TIMER_TVR 0x00
-#define OMAP_32K_TIMER_TCR 0x04
-
-#define OMAP_32K_TICKS_PER_HZ (32768 / HZ)
-
-/*
- * TRM says 1 / HZ = ( TVR + 1) / 32768, so TRV = (32768 / HZ) - 1
- * so with HZ = 100, TVR = 327.68.
- */
-#define OMAP_32K_TIMER_TICK_PERIOD ((32768 / HZ) - 1)
-#define TIMER_32K_SYNCHRONIZED 0xfffbc410
-
-#define JIFFIES_TO_HW_TICKS(nr_jiffies, clock_rate) \
- (((nr_jiffies) * (clock_rate)) / HZ)
-static inline void omap_32k_timer_write(int val, int reg)
-{
- omap_writew(val, reg + OMAP_32K_TIMER_BASE);
-}
+static unsigned long omap_mpu_timer2_overflows;
-static inline unsigned long omap_32k_timer_read(int reg)
+static irqreturn_t omap_mpu_timer2_interrupt(int irq, void *dev_id)
{
- return omap_readl(reg + OMAP_32K_TIMER_BASE) & 0xffffff;
-}
-
-/*
- * The 32KHz synchronized timer is an additional timer on 16xx.
- * It is always running.
- */
-static inline unsigned long omap_32k_sync_timer_read(void)
-{
- return omap_readl(TIMER_32K_SYNCHRONIZED);
+ omap_mpu_timer2_overflows++;
+ return IRQ_HANDLED;
}
-static inline void omap_32k_timer_start(unsigned long load_val)
-{
- omap_32k_timer_write(load_val, OMAP_32K_TIMER_TVR);
- omap_32k_timer_write(0x0f, OMAP_32K_TIMER_CR);
-}
+static struct irqaction omap_mpu_timer2_irq = {
+ .name = "mpu_timer2",
+ .flags = IRQF_DISABLED,
+ .handler = omap_mpu_timer2_interrupt,
+};
-static inline void omap_32k_timer_stop(void)
+static cycle_t mpu_read(void)
{
- omap_32k_timer_write(0x0, OMAP_32K_TIMER_CR);
+ return ~omap_mpu_timer_read(1);
}
-/*
- * Rounds down to nearest usec. Note that this will overflow for larger values.
- */
-static inline unsigned long omap_32k_ticks_to_usecs(unsigned long ticks_32k)
-{
- return (ticks_32k * 5*5*5*5*5*5) >> 9;
-}
+static struct clocksource clocksource_mpu = {
+ .name = "mpu_timer2",
+ .rating = 300,
+ .read = mpu_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .shift = 24,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
-/*
- * Rounds down to nearest nsec.
- */
-static inline unsigned long long
-omap_32k_ticks_to_nsecs(unsigned long ticks_32k)
+static void __init omap_init_clocksource(unsigned long rate)
{
- return (unsigned long long) ticks_32k * 1000 * 5*5*5*5*5*5 >> 9;
-}
+ static char err[] __initdata = KERN_ERR
+ "%s: can't register clocksource!\n";
-static unsigned long omap_32k_last_tick = 0;
+ clocksource_mpu.mult
+ = clocksource_khz2mult(rate/1000, clocksource_mpu.shift);
-/*
- * Returns elapsed usecs since last 32k timer interrupt
- */
-static unsigned long omap_32k_timer_gettimeoffset(void)
-{
- unsigned long now = omap_32k_sync_timer_read();
- return omap_32k_ticks_to_usecs(now - omap_32k_last_tick);
-}
+ setup_irq(INT_TIMER2, &omap_mpu_timer2_irq);
+ omap_mpu_timer_start(1, ~0, 1);
-/*
- * Returns current time from boot in nsecs. It's OK for this to wrap
- * around for now, as it's just a relative time stamp.
- */
-unsigned long long sched_clock(void)
-{
- return omap_32k_ticks_to_nsecs(omap_32k_sync_timer_read());
+ if (clocksource_register(&clocksource_mpu))
+ printk(err, clocksource_mpu.name);
}
-/*
- * Timer interrupt for 32KHz timer. When dynamic tick is enabled, this
- * function is also called from other interrupts to remove latency
- * issues with dynamic tick. In the dynamic tick case, we need to lock
- * with irqsave.
- */
-static irqreturn_t omap_32k_timer_interrupt(int irq, void *dev_id,
- struct pt_regs *regs)
-{
- unsigned long flags;
- unsigned long now;
-
- write_seqlock_irqsave(&xtime_lock, flags);
- now = omap_32k_sync_timer_read();
-
- while (now - omap_32k_last_tick >= OMAP_32K_TICKS_PER_HZ) {
- omap_32k_last_tick += OMAP_32K_TICKS_PER_HZ;
- timer_tick(regs);
- }
-
- /* Restart timer so we don't drift off due to modulo or dynamic tick.
- * By default we program the next timer to be continuous to avoid
- * latencies during high system load. During dynamic tick operation the
- * continuous timer can be overridden from pm_idle to be longer.
- */
- omap_32k_timer_start(omap_32k_last_tick + OMAP_32K_TICKS_PER_HZ - now);
- write_sequnlock_irqrestore(&xtime_lock, flags);
- return IRQ_HANDLED;
-}
-
-#ifdef CONFIG_NO_IDLE_HZ
/*
- * Programs the next timer interrupt needed. Called when dynamic tick is
- * enabled, and to reprogram the ticks to skip from pm_idle. Note that
- * we can keep the timer continuous, and don't need to set it to run in
- * one-shot mode. This is because the timer will get reprogrammed again
- * after next interrupt.
+ * Scheduler clock - returns current time in nanosec units.
*/
-void omap_32k_timer_reprogram(unsigned long next_tick)
-{
- omap_32k_timer_start(JIFFIES_TO_HW_TICKS(next_tick, 32768) + 1);
-}
-
-static struct irqaction omap_32k_timer_irq;
-extern struct timer_update_handler timer_update;
-
-static int omap_32k_timer_enable_dyn_tick(void)
-{
- /* No need to reprogram timer, just use the next interrupt */
- return 0;
-}
-
-static int omap_32k_timer_disable_dyn_tick(void)
-{
- omap_32k_timer_start(OMAP_32K_TIMER_TICK_PERIOD);
- return 0;
-}
-
-static struct dyn_tick_timer omap_dyn_tick_timer = {
- .enable = omap_32k_timer_enable_dyn_tick,
- .disable = omap_32k_timer_disable_dyn_tick,
- .reprogram = omap_32k_timer_reprogram,
- .handler = omap_32k_timer_interrupt,
-};
-#endif /* CONFIG_NO_IDLE_HZ */
-
-static struct irqaction omap_32k_timer_irq = {
- .name = "32KHz timer",
- .flags = SA_INTERRUPT | SA_TIMER,
- .handler = omap_32k_timer_interrupt,
-};
-
-static __init void omap_init_32k_timer(void)
+unsigned long long sched_clock(void)
{
+ unsigned long ticks = 0 - omap_mpu_timer_read(1);
+ unsigned long long ticks64;
-#ifdef CONFIG_NO_IDLE_HZ
- omap_timer.dyn_tick = &omap_dyn_tick_timer;
-#endif
+ ticks64 = omap_mpu_timer2_overflows;
+ ticks64 <<= 32;
+ ticks64 |= ticks;
- setup_irq(INT_OS_TIMER, &omap_32k_timer_irq);
- omap_timer.offset = omap_32k_timer_gettimeoffset;
- omap_32k_last_tick = omap_32k_sync_timer_read();
- omap_32k_timer_start(OMAP_32K_TIMER_TICK_PERIOD);
+ return cycles_2_ns(ticks64);
}
-#endif /* CONFIG_OMAP_32K_TIMER */
/*
* ---------------------------------------------------------------------------
*/
static void __init omap_timer_init(void)
{
-#if defined(CONFIG_OMAP_MPU_TIMER)
- omap_init_mpu_timer();
-#elif defined(CONFIG_OMAP_32K_TIMER)
- omap_init_32k_timer();
-#else
-#error No system timer selected in Kconfig!
-#endif
+ struct clk *ck_ref = clk_get(NULL, "ck_ref");
+ unsigned long rate;
+
+ BUG_ON(IS_ERR(ck_ref));
+
+ rate = clk_get_rate(ck_ref);
+ clk_put(ck_ref);
+
+ /* PTV = 0 */
+ rate /= 2;
+
+ omap_init_mpu_timer(rate);
+ omap_init_clocksource(rate);
}
struct sys_timer omap_timer = {
.init = omap_timer_init,
- .offset = NULL, /* Initialized later */
};
projects / linux-2.6-omap-h63xx.git / blobdiff