msm: timer: SMP timer support for msm
The msm provides timer hardware that is private to each core. Each
timer has separate counter and match registers, so we create separate
clock_event_devices for each core. For the global clocksource, use
cpu 0's counter.
Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c
index 595be7f..c105d28 100644
--- a/arch/arm/mach-msm/timer.c
+++ b/arch/arm/mach-msm/timer.c
@@ -47,6 +47,19 @@
#define GPT_HZ 32768
+enum timer_location {
+ LOCAL_TIMER = 0,
+ GLOBAL_TIMER = 1,
+};
+
+#ifdef MSM_TMR0_BASE
+#define MSM_TMR_GLOBAL (MSM_TMR0_BASE - MSM_TMR_BASE)
+#else
+#define MSM_TMR_GLOBAL 0
+#endif
+
+#define MSM_GLOBAL_TIMER MSM_CLOCK_DGT
+
#if defined(CONFIG_ARCH_QSD8X50)
#define DGT_HZ (19200000 / 4) /* 19.2 MHz / 4 by default */
#define MSM_DGT_SHIFT (0)
@@ -65,49 +78,67 @@
void __iomem *regbase;
uint32_t freq;
uint32_t shift;
+ void __iomem *global_counter;
+ void __iomem *local_counter;
};
+enum {
+ MSM_CLOCK_GPT,
+ MSM_CLOCK_DGT,
+ NR_TIMERS,
+};
+
+
+static struct msm_clock msm_clocks[];
+static struct clock_event_device *local_clock_event;
+
static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
+ if (smp_processor_id() != 0)
+ evt = local_clock_event;
+ if (evt->event_handler == NULL)
+ return IRQ_HANDLED;
evt->event_handler(evt);
return IRQ_HANDLED;
}
-static cycle_t msm_gpt_read(struct clocksource *cs)
+static cycle_t msm_read_timer_count(struct clocksource *cs)
{
- return readl(MSM_GPT_BASE + TIMER_COUNT_VAL);
+ struct msm_clock *clk = container_of(cs, struct msm_clock, clocksource);
+
+ return readl(clk->global_counter);
}
-static cycle_t msm_dgt_read(struct clocksource *cs)
+static struct msm_clock *clockevent_to_clock(struct clock_event_device *evt)
{
- return readl(MSM_DGT_BASE + TIMER_COUNT_VAL) >> MSM_DGT_SHIFT;
+#ifdef CONFIG_SMP
+ int i;
+ for (i = 0; i < NR_TIMERS; i++)
+ if (evt == &(msm_clocks[i].clockevent))
+ return &msm_clocks[i];
+ return &msm_clocks[MSM_GLOBAL_TIMER];
+#else
+ return container_of(evt, struct msm_clock, clockevent);
+#endif
}
static int msm_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
- struct msm_clock *clock = container_of(evt, struct msm_clock, clockevent);
- uint32_t now = readl(clock->regbase + TIMER_COUNT_VAL);
+ struct msm_clock *clock = clockevent_to_clock(evt);
+ uint32_t now = readl(clock->local_counter);
uint32_t alarm = now + (cycles << clock->shift);
- int late;
writel(alarm, clock->regbase + TIMER_MATCH_VAL);
- now = readl(clock->regbase + TIMER_COUNT_VAL);
- late = now - alarm;
- if (late >= (-2 << clock->shift) && late < DGT_HZ*5) {
- printk(KERN_NOTICE "msm_timer_set_next_event(%lu) clock %s, "
- "alarm already expired, now %x, alarm %x, late %d\n",
- cycles, clock->clockevent.name, now, alarm, late);
- return -ETIME;
- }
return 0;
}
static void msm_timer_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
- struct msm_clock *clock = container_of(evt, struct msm_clock, clockevent);
+ struct msm_clock *clock = clockevent_to_clock(evt);
+
switch (mode) {
case CLOCK_EVT_MODE_RESUME:
case CLOCK_EVT_MODE_PERIODIC:
@@ -123,7 +154,7 @@
}
static struct msm_clock msm_clocks[] = {
- {
+ [MSM_CLOCK_GPT] = {
.clockevent = {
.name = "gp_timer",
.features = CLOCK_EVT_FEAT_ONESHOT,
@@ -135,7 +166,7 @@
.clocksource = {
.name = "gp_timer",
.rating = 200,
- .read = msm_gpt_read,
+ .read = msm_read_timer_count,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
},
@@ -147,9 +178,12 @@
.irq = INT_GP_TIMER_EXP
},
.regbase = MSM_GPT_BASE,
- .freq = GPT_HZ
+ .freq = GPT_HZ,
+ .local_counter = MSM_GPT_BASE + TIMER_COUNT_VAL,
+ .global_counter = MSM_GPT_BASE + TIMER_COUNT_VAL +
+ MSM_TMR_GLOBAL,
},
- {
+ [MSM_CLOCK_DGT] = {
.clockevent = {
.name = "dg_timer",
.features = CLOCK_EVT_FEAT_ONESHOT,
@@ -161,7 +195,7 @@
.clocksource = {
.name = "dg_timer",
.rating = 300,
- .read = msm_dgt_read,
+ .read = msm_read_timer_count,
.mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT)),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
},
@@ -174,7 +208,10 @@
},
.regbase = MSM_DGT_BASE,
.freq = DGT_HZ >> MSM_DGT_SHIFT,
- .shift = MSM_DGT_SHIFT
+ .shift = MSM_DGT_SHIFT,
+ .local_counter = MSM_DGT_BASE + TIMER_COUNT_VAL,
+ .global_counter = MSM_DGT_BASE + TIMER_COUNT_VAL +
+ MSM_TMR_GLOBAL,
}
};
@@ -183,7 +220,7 @@
int i;
int res;
-#ifdef CONFIG_ARCH_MSM8X60
+#ifdef CONFIG_ARCH_MSM_SCORPIONMP
writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
#endif
@@ -217,6 +254,48 @@
}
}
+#ifdef CONFIG_SMP
+void __cpuinit local_timer_setup(struct clock_event_device *evt)
+{
+ struct msm_clock *clock = &msm_clocks[MSM_GLOBAL_TIMER];
+
+ /* Use existing clock_event for cpu 0 */
+ if (!smp_processor_id())
+ return;
+
+ writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
+
+ if (!local_clock_event) {
+ writel(0, clock->regbase + TIMER_ENABLE);
+ writel(0, clock->regbase + TIMER_CLEAR);
+ writel(~0, clock->regbase + TIMER_MATCH_VAL);
+ }
+ evt->irq = clock->irq.irq;
+ evt->name = "local_timer";
+ evt->features = CLOCK_EVT_FEAT_ONESHOT;
+ evt->rating = clock->clockevent.rating;
+ evt->set_mode = msm_timer_set_mode;
+ evt->set_next_event = msm_timer_set_next_event;
+ evt->shift = clock->clockevent.shift;
+ evt->mult = div_sc(clock->freq, NSEC_PER_SEC, evt->shift);
+ evt->max_delta_ns =
+ clockevent_delta2ns(0xf0000000 >> clock->shift, evt);
+ evt->min_delta_ns = clockevent_delta2ns(4, evt);
+
+ local_clock_event = evt;
+
+ gic_enable_ppi(clock->irq.irq);
+
+ clockevents_register_device(evt);
+}
+
+inline int local_timer_ack(void)
+{
+ return 1;
+}
+
+#endif
+
struct sys_timer msm_timer = {
.init = msm_timer_init
};