/*
- * linux/arch/kernel/time-ts.c
- *
* Based on arm clockevents implementation and old bfin time tick.
*
- * Copyright(C) 2008, GeoTechnologies, Vitja Makarov
+ * Copyright 2008-2009 Analog Devics Inc.
+ * 2008 GeoTechnologies
+ * Vitja Makarov
*
- * This code is licenced under the GPL version 2. For details see
- * kernel-base/COPYING.
+ * Licensed under the GPL-2
*/
+
#include <linux/module.h>
#include <linux/profile.h>
#include <linux/interrupt.h>
#include <linux/time.h>
+#include <linux/timex.h>
#include <linux/irq.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
+#include <linux/cpufreq.h>
#include <asm/blackfin.h>
+#include <asm/time.h>
+#include <asm/gptimers.h>
-#ifdef CONFIG_CYCLES_CLOCKSOURCE
+#if defined(CONFIG_CYCLES_CLOCKSOURCE)
+
+/* Accelerators for sched_clock()
+ * convert from cycles(64bits) => nanoseconds (64bits)
+ * basic equation:
+ * ns = cycles / (freq / ns_per_sec)
+ * ns = cycles * (ns_per_sec / freq)
+ * ns = cycles * (10^9 / (cpu_khz * 10^3))
+ * ns = cycles * (10^6 / cpu_khz)
+ *
+ * Then we use scaling math (suggested by george@mvista.com) to get:
+ * ns = cycles * (10^6 * SC / cpu_khz) / SC
+ * ns = cycles * cyc2ns_scale / SC
+ *
+ * And since SC is a constant power of two, we can convert the div
+ * into a shift.
+ *
+ * We can use khz divisor instead of mhz to keep a better precision, since
+ * cyc2ns_scale is limited to 10^6 * 2^10, which fits in 32 bits.
+ * (mathieu.desnoyers@polymtl.ca)
+ *
+ * -johnstul@us.ibm.com "math is hard, lets go shopping!"
+ */
static unsigned long cyc2ns_scale;
#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
}
-static cycle_t read_cycles(void)
+static cycle_t bfin_read_cycles(struct clocksource *cs)
{
- unsigned long tmp, tmp2;
- asm("%0 = cycles; %1 = cycles2;" : "=d"(tmp), "=d"(tmp2));
- return tmp | ((cycle_t)tmp2 << 32);
+ return __bfin_cycles_off + (get_cycles() << __bfin_cycles_mod);
}
+static struct clocksource bfin_cs_cycles = {
+ .name = "bfin_cs_cycles",
+ .rating = 400,
+ .read = bfin_read_cycles,
+ .mask = CLOCKSOURCE_MASK(64),
+ .shift = 22,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
unsigned long long sched_clock(void)
{
- return cycles_2_ns(read_cycles());
+ return cycles_2_ns(bfin_read_cycles(&bfin_cs_cycles));
}
-static struct clocksource clocksource_bfin = {
- .name = "bfin_cycles",
+static int __init bfin_cs_cycles_init(void)
+{
+ set_cyc2ns_scale(get_cclk() / 1000);
+
+ bfin_cs_cycles.mult = \
+ clocksource_hz2mult(get_cclk(), bfin_cs_cycles.shift);
+
+ if (clocksource_register(&bfin_cs_cycles))
+ panic("failed to register clocksource");
+
+ return 0;
+}
+#else
+# define bfin_cs_cycles_init()
+#endif
+
+#ifdef CONFIG_GPTMR0_CLOCKSOURCE
+
+void __init setup_gptimer0(void)
+{
+ disable_gptimers(TIMER0bit);
+
+ set_gptimer_config(TIMER0_id, \
+ TIMER_OUT_DIS | TIMER_PERIOD_CNT | TIMER_MODE_PWM);
+ set_gptimer_period(TIMER0_id, -1);
+ set_gptimer_pwidth(TIMER0_id, -2);
+ SSYNC();
+ enable_gptimers(TIMER0bit);
+}
+
+static cycle_t bfin_read_gptimer0(void)
+{
+ return bfin_read_TIMER0_COUNTER();
+}
+
+static struct clocksource bfin_cs_gptimer0 = {
+ .name = "bfin_cs_gptimer0",
.rating = 350,
- .read = read_cycles,
- .mask = CLOCKSOURCE_MASK(64),
+ .read = bfin_read_gptimer0,
+ .mask = CLOCKSOURCE_MASK(32),
.shift = 22,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
-static int __init bfin_clocksource_init(void)
+static int __init bfin_cs_gptimer0_init(void)
{
- set_cyc2ns_scale(get_cclk() / 1000);
+ setup_gptimer0();
- clocksource_bfin.mult = clocksource_hz2mult(get_cclk(), clocksource_bfin.shift);
+ bfin_cs_gptimer0.mult = \
+ clocksource_hz2mult(get_sclk(), bfin_cs_gptimer0.shift);
- if (clocksource_register(&clocksource_bfin))
+ if (clocksource_register(&bfin_cs_gptimer0))
panic("failed to register clocksource");
return 0;
}
+#else
+# define bfin_cs_gptimer0_init()
+#endif
+
+#ifdef CONFIG_CORE_TIMER_IRQ_L1
+__attribute__((l1_text))
+#endif
+irqreturn_t timer_interrupt(int irq, void *dev_id);
+
+static int bfin_timer_set_next_event(unsigned long, \
+ struct clock_event_device *);
+
+static void bfin_timer_set_mode(enum clock_event_mode, \
+ struct clock_event_device *);
+
+static struct clock_event_device clockevent_bfin = {
+#if defined(CONFIG_TICKSOURCE_GPTMR0)
+ .name = "bfin_gptimer0",
+ .rating = 300,
+ .irq = IRQ_TIMER0,
+#else
+ .name = "bfin_core_timer",
+ .rating = 350,
+ .irq = IRQ_CORETMR,
+#endif
+ .shift = 32,
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .set_next_event = bfin_timer_set_next_event,
+ .set_mode = bfin_timer_set_mode,
+};
+static struct irqaction bfin_timer_irq = {
+#if defined(CONFIG_TICKSOURCE_GPTMR0)
+ .name = "Blackfin GPTimer0",
#else
-# define bfin_clocksource_init()
+ .name = "Blackfin CoreTimer",
#endif
+ .flags = IRQF_DISABLED | IRQF_TIMER | \
+ IRQF_IRQPOLL | IRQF_PERCPU,
+ .handler = timer_interrupt,
+ .dev_id = &clockevent_bfin,
+};
+#if defined(CONFIG_TICKSOURCE_GPTMR0)
static int bfin_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
+ disable_gptimers(TIMER0bit);
+
+ /* it starts counting three SCLK cycles after the TIMENx bit is set */
+ set_gptimer_pwidth(TIMER0_id, cycles - 3);
+ enable_gptimers(TIMER0bit);
+ return 0;
+}
+
+static void bfin_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC: {
+ set_gptimer_config(TIMER0_id, \
+ TIMER_OUT_DIS | TIMER_IRQ_ENA | \
+ TIMER_PERIOD_CNT | TIMER_MODE_PWM);
+ set_gptimer_period(TIMER0_id, get_sclk() / HZ);
+ set_gptimer_pwidth(TIMER0_id, get_sclk() / HZ - 1);
+ enable_gptimers(TIMER0bit);
+ break;
+ }
+ case CLOCK_EVT_MODE_ONESHOT:
+ disable_gptimers(TIMER0bit);
+ set_gptimer_config(TIMER0_id, \
+ TIMER_OUT_DIS | TIMER_IRQ_ENA | TIMER_MODE_PWM);
+ set_gptimer_period(TIMER0_id, 0);
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ disable_gptimers(TIMER0bit);
+ break;
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+ }
+}
+
+static void bfin_timer_ack(void)
+{
+ set_gptimer_status(TIMER_GROUP1, TIMER_STATUS_TIMIL0);
+}
+
+static void __init bfin_timer_init(void)
+{
+ disable_gptimers(TIMER0bit);
+}
+
+static unsigned long __init bfin_clockevent_check(void)
+{
+ setup_irq(IRQ_TIMER0, &bfin_timer_irq);
+ return get_sclk();
+}
+
+#else /* CONFIG_TICKSOURCE_CORETMR */
+
+static int bfin_timer_set_next_event(unsigned long cycles,
+ struct clock_event_device *evt)
+{
+ bfin_write_TCNTL(TMPWR);
+ CSYNC();
bfin_write_TCOUNT(cycles);
CSYNC();
+ bfin_write_TCNTL(TMPWR | TMREN);
return 0;
}
static void bfin_timer_set_mode(enum clock_event_mode mode,
- struct clock_event_device *evt)
+ struct clock_event_device *evt)
{
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC: {
- unsigned long tcount = ((get_cclk() / (HZ * 1)) - 1);
+ unsigned long tcount = ((get_cclk() / (HZ * TIME_SCALE)) - 1);
bfin_write_TCNTL(TMPWR);
CSYNC();
+ bfin_write_TSCALE(TIME_SCALE - 1);
bfin_write_TPERIOD(tcount);
bfin_write_TCOUNT(tcount);
- bfin_write_TCNTL(TMPWR | TMREN | TAUTORLD);
CSYNC();
+ bfin_write_TCNTL(TMPWR | TMREN | TAUTORLD);
break;
}
case CLOCK_EVT_MODE_ONESHOT:
- bfin_write_TCOUNT(0);
- bfin_write_TCNTL(TMPWR | TMREN);
+ bfin_write_TCNTL(TMPWR);
CSYNC();
+ bfin_write_TSCALE(TIME_SCALE - 1);
+ bfin_write_TPERIOD(0);
+ bfin_write_TCOUNT(0);
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
}
}
+static void bfin_timer_ack(void)
+{
+}
+
static void __init bfin_timer_init(void)
{
/* power up the timer, but don't enable it just yet */
/*
* the TSCALE prescaler counter.
*/
- bfin_write_TSCALE(0);
+ bfin_write_TSCALE(TIME_SCALE - 1);
bfin_write_TPERIOD(0);
bfin_write_TCOUNT(0);
- /* now enable the timer */
CSYNC();
}
+static unsigned long __init bfin_clockevent_check(void)
+{
+ setup_irq(IRQ_CORETMR, &bfin_timer_irq);
+ return get_cclk() / TIME_SCALE;
+}
+
+void __init setup_core_timer(void)
+{
+ bfin_timer_init();
+ bfin_timer_set_mode(CLOCK_EVT_MODE_PERIODIC, NULL);
+}
+#endif /* CONFIG_TICKSOURCE_GPTMR0 */
+
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
*/
-#ifdef CONFIG_CORE_TIMER_IRQ_L1
-__attribute__((l1_text))
-#endif
-irqreturn_t timer_interrupt(int irq, void *dev_id);
-
-static struct clock_event_device clockevent_bfin = {
- .name = "bfin_core_timer",
- .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
- .shift = 32,
- .cpumask = CPU_MASK_CPU0,
- .set_next_event = bfin_timer_set_next_event,
- .set_mode = bfin_timer_set_mode,
-};
-
-static struct irqaction bfin_timer_irq = {
- .name = "Blackfin Core Timer",
- .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
- .handler = timer_interrupt,
- .dev_id = &clockevent_bfin,
-};
-
irqreturn_t timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
+ smp_mb();
evt->event_handler(evt);
+ bfin_timer_ack();
return IRQ_HANDLED;
}
static int __init bfin_clockevent_init(void)
{
- setup_irq(IRQ_CORETMR, &bfin_timer_irq);
+ unsigned long timer_clk;
+
+ timer_clk = bfin_clockevent_check();
+
bfin_timer_init();
- clockevent_bfin.mult = div_sc(get_cclk(), NSEC_PER_SEC, clockevent_bfin.shift);
+ clockevent_bfin.mult = div_sc(timer_clk, NSEC_PER_SEC, clockevent_bfin.shift);
clockevent_bfin.max_delta_ns = clockevent_delta2ns(-1, &clockevent_bfin);
clockevent_bfin.min_delta_ns = clockevent_delta2ns(100, &clockevent_bfin);
+ clockevent_bfin.cpumask = cpumask_of(0);
clockevents_register_device(&clockevent_bfin);
return 0;
xtime.tv_nsec = 0;
set_normalized_timespec(&wall_to_monotonic, -xtime.tv_sec, -xtime.tv_nsec);
- bfin_clocksource_init();
+ bfin_cs_cycles_init();
+ bfin_cs_gptimer0_init();
bfin_clockevent_init();
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff