[ARM] tegra: timer: Add suspend wakeup and 32khz timers

the LP2 idle state can not be woken by the internal ARM timers,
so reserve the last APB system timer for use as an LP2 wakeup
trigger

Signed-off-by: Colin Cross <ccross@android.com>

1 files changed, 123 insertions, 13 deletions

diff --git a/arch/arm/mach-tegra/timer.c b/arch/arm/mach-tegra/timer.c
index 363217308285..cc9ec7020533 100644
--- a/arch/arm/mach-tegra/timer.c
+++ b/arch/arm/mach-tegra/timer.c
@@ -38,6 +38,10 @@
 #include "board.h"
 #include "clock.h"
 
+#define RTC_SECONDS		0x08
+#define RTC_SHADOW_SECONDS	0x0c
+#define RTC_MILLISECONDS	0x10
+
 #define TIMERUS_CNTR_1US 0x10
 #define TIMERUS_USEC_CFG 0x14
 #define TIMERUS_CNTR_FREEZE 0x4c
@@ -50,14 +54,13 @@
 #define TIMER_PTV 0x0
 #define TIMER_PCR 0x4
 
-struct tegra_timer;
-
-static void __iomem *timer_reg_base = IO_ADDRESS(TEGRA_TMR1_BASE);
+static void __iomem *timer_base = IO_ADDRESS(TEGRA_TMR1_BASE);
+static void __iomem *rtc_base = IO_ADDRESS(TEGRA_RTC_BASE);
 
 #define timer_writel(value, reg) \
-	__raw_writel(value, (u32)timer_reg_base + (reg))
+	__raw_writel(value, (u32)timer_base + (reg))
 #define timer_readl(reg) \
-	__raw_readl((u32)timer_reg_base + (reg))
+	__raw_readl((u32)timer_base + (reg))
 
 static int tegra_timer_set_next_event(unsigned long cycles,
 					 struct clock_event_device *evt)
@@ -91,9 +94,29 @@ static void tegra_timer_set_mode(enum clock_event_mode mode,
 	}
 }
 
-static cycle_t tegra_clocksource_read(struct clocksource *cs)
+static u64 tegra_us_clocksource_offset;
+static u64 tegra_us_resume_offset;
+static cycle_t tegra_clocksource_us_read(struct clocksource *cs)
 {
-	return cnt32_to_63(timer_readl(TIMERUS_CNTR_1US));
+	return tegra_us_clocksource_offset +
+		cnt32_to_63(timer_readl(TIMERUS_CNTR_1US));
+}
+
+void tegra_clocksource_us_suspend(struct clocksource *cs)
+{
+	tegra_us_resume_offset = tegra_clocksource_us_read(cs);
+}
+
+void tegra_clocksource_us_resume(struct clocksource *cs)
+{
+	tegra_us_clocksource_offset = tegra_us_resume_offset;
+}
+
+static cycle_t tegra_clocksource_32k_read(struct clocksource *cs)
+{
+	u32 ms = readl(rtc_base + RTC_MILLISECONDS);
+	u32 s = readl(rtc_base + RTC_SHADOW_SECONDS);
+	return (u64)s * 1000 + ms;
 }
 
 static struct clock_event_device tegra_clockevent = {
@@ -104,18 +127,54 @@ static struct clock_event_device tegra_clockevent = {
 	.set_mode	= tegra_timer_set_mode,
 };
 
-static struct clocksource tegra_clocksource = {
+static struct clocksource tegra_clocksource_us = {
 	.name	= "timer_us",
 	.rating	= 300,
-	.read	= tegra_clocksource_read,
+	.read	= tegra_clocksource_us_read,
+	.suspend= tegra_clocksource_us_suspend,
+	.resume	= tegra_clocksource_us_resume,
+	.mask	= 0x7FFFFFFFFFFFFFFFULL,
+	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static struct clocksource tegra_clocksource_32k = {
+	.name	= "rtc_32k",
+	.rating	= 100,
+	.read	= tegra_clocksource_32k_read,
 	.mask	= 0x7FFFFFFFFFFFFFFFULL,
 	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
 unsigned long long sched_clock(void)
 {
-	return clocksource_cyc2ns(tegra_clocksource.read(&tegra_clocksource),
-		tegra_clocksource.mult, tegra_clocksource.shift);
+	return tegra_clocksource_us.read(&tegra_clocksource_us) * 1000;
+}
+
+/**
+ * read_persistent_clock -  Return time from a persistent clock.
+ *
+ * Reads the time from a source which isn't disabled during PM, the
+ * 32k sync timer.  Convert the cycles elapsed since last read into
+ * nsecs and adds to a monotonically increasing timespec.
+ */
+static struct timespec persistent_ts;
+static cycles_t cycles, last_cycles;
+void read_persistent_clock(struct timespec *ts)
+{
+	unsigned long long nsecs;
+	cycles_t delta;
+	struct timespec *tsp = &persistent_ts;
+
+	last_cycles = cycles;
+	cycles = tegra_clocksource_32k.read(&tegra_clocksource_32k);
+	delta = cycles - last_cycles;
+
+	nsecs = clocksource_cyc2ns(delta,
+				   tegra_clocksource_32k.mult,
+				   tegra_clocksource_32k.shift);
+
+	timespec_add_ns(tsp, nsecs);
+	*ts = *tsp;
 }
 
 static irqreturn_t tegra_timer_interrupt(int irq, void *dev_id)
@@ -134,6 +193,20 @@ static struct irqaction tegra_timer_irq = {
 	.irq		= INT_TMR3,
 };
 
+static irqreturn_t tegra_lp2wake_interrupt(int irq, void *dev_id)
+{
+	timer_writel(1<<30, TIMER4_BASE + TIMER_PCR);
+	return IRQ_HANDLED;
+}
+
+static struct irqaction tegra_lp2wake_irq = {
+	.name		= "timer_lp2wake",
+	.flags		= IRQF_DISABLED,
+	.handler	= tegra_lp2wake_interrupt,
+	.dev_id		= NULL,
+	.irq		= INT_TMR4,
+};
+
 static void __init tegra_init_timer(void)
 {
 	unsigned long rate = clk_measure_input_freq();
@@ -160,8 +233,13 @@ static void __init tegra_init_timer(void)
 		WARN(1, "Unknown clock rate");
 	}
 
-	if (clocksource_register_hz(&tegra_clocksource, 1000000)) {
-		printk(KERN_ERR "Failed to register clocksource\n");
+	if (clocksource_register_hz(&tegra_clocksource_us, 1000000)) {
+		printk(KERN_ERR "Failed to register us clocksource\n");
+		BUG();
+	}
+
+	if (clocksource_register_hz(&tegra_clocksource_32k, 1000)) {
+		printk(KERN_ERR "Failed to register 32k clocksource\n");
 		BUG();
 	}
 
@@ -171,6 +249,12 @@ static void __init tegra_init_timer(void)
 		BUG();
 	}
 
+	ret = setup_irq(tegra_lp2wake_irq.irq, &tegra_lp2wake_irq);
+	if (ret) {
+		printk(KERN_ERR "Failed to register LP2 timer IRQ: %d\n", ret);
+		BUG();
+	}
+
 	clockevents_calc_mult_shift(&tegra_clockevent, 1000000, 5);
 	tegra_clockevent.max_delta_ns =
 		clockevent_delta2ns(0x1fffffff, &tegra_clockevent);
@@ -186,3 +270,29 @@ static void __init tegra_init_timer(void)
 struct sys_timer tegra_timer = {
 	.init = tegra_init_timer,
 };
+
+void tegra_lp2_set_trigger(unsigned long cycles)
+{
+	timer_writel(0, TIMER4_BASE + TIMER_PTV);
+	if (cycles) {
+		u32 reg = 0x80000000ul | min(0x1ffffffful, cycles);
+		timer_writel(reg, TIMER4_BASE + TIMER_PTV);
+	}
+}
+EXPORT_SYMBOL(tegra_lp2_set_trigger);
+
+unsigned long tegra_lp2_timer_remain(void)
+{
+	return timer_readl(TIMER4_BASE + TIMER_PCR) & 0x1ffffffful;
+}
+
+static u32 usec_config;
+void tegra_timer_suspend(void)
+{
+	usec_config = timer_readl(TIMERUS_USEC_CFG);
+}
+
+void tegra_timer_resume(void)
+{
+	timer_writel(usec_config, TIMERUS_USEC_CFG);
+}