Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/…

…linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "A rather smalish set of updates for timers and timekeeping:

   - Two core fixes to prevent potential undefinded behaviour about
     which gcc is complaining rightfully.

   - A fix to prevent stopping the tick on an (soon) offline CPU so it
     can complete the shutdown procedure.

   - Wait for clocks to stabilize before making decisions, so a not yet
     validated clock is not rejected.

   - The usual pile of fixes to the various clocksource drivers.

   - Core code typo and include fixlets"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Include the correct header for errno definitions
  clocksource/drivers/ti-32k: Prevent ftrace recursion
  clocksource/mips-gic-timer: Stop checking cpu_has_counter
  clocksource/mips-gic-timer: Print an error if IRQ setup fails
  tick/nohz: Prevent stopping the tick on an offline CPU
  clocksource/drivers/oxnas: Add OX820 compatible
  clocksource/drivers/timer-atmel-pit: Simplify IRQ handler
  clocksource/drivers/timer-atmel-pit: Remove uselesss WARN_ON_ONCE
  clocksource/drivers/timer-atmel-pit: Drop at91sam926x_pit_common_init
  clocksource/drivers/moxart: Replace panic by pr_err
  clocksource/drivers/moxart: Replace setup_irq by request_irq
  clocksource/drivers/moxart: Add Aspeed support
  clocksource/drivers/moxart: Use struct to hold state
  clocksource/drivers/moxart: Refactor enable/disable
  time: Avoid undefined behaviour in ktime_add_safe()
  time: Avoid undefined behaviour in timespec64_add_safe()
  timekeeping: Prints the amounts of time spent during suspend
  clocksource: Defer override invalidation unless clock is unstable
  hrtimer: Spelling fixes

Documentation/devicetree/bindings/timer/moxa,moxart-timer.txt

@@ -2,7 +2,9 @@ MOXA ART timer
 
 Required properties:
 
-- compatible : Must be "moxa,moxart-timer"
+- compatible : Must be one of:
+ 	- "moxa,moxart-timer"
+ 	- "aspeed,ast2400-timer"
 - reg : Should contain registers location and length
 - interrupts : Should contain the timer interrupt number
 - clocks : Should contain phandle for the clock that drives the counter

Documentation/devicetree/bindings/timer/oxsemi,rps-timer.txt

@@ -2,7 +2,7 @@ Oxford Semiconductor OXNAS SoCs Family RPS Timer
 ================================================
 
 Required properties:
-- compatible: Should be "oxsemi,ox810se-rps-timer"
+- compatible: Should be "oxsemi,ox810se-rps-timer" or "oxsemi,ox820-rps-timer"
 - reg : Specifies base physical address and size of the registers.
 - interrupts : The interrupts of the two timers
 - clocks : The phandle of the timer clock source

drivers/clocksource/mips-gic-timer.c

@@ -109,12 +109,15 @@ static int gic_clockevent_init(void)
 {
 	int ret;
 
-	if (!cpu_has_counter || !gic_frequency)
+	if (!gic_frequency)
 		return -ENXIO;
 
 	ret = setup_percpu_irq(gic_timer_irq, &gic_compare_irqaction);
-	if (ret < 0)
+	if (ret < 0) {
+		pr_err("GIC timer IRQ %d setup failed: %d\n",
+		       gic_timer_irq, ret);
 		return ret;
+	}
 
 	cpuhp_setup_state(CPUHP_AP_MIPS_GIC_TIMER_STARTING,
 			  "AP_MIPS_GIC_TIMER_STARTING", gic_starting_cpu,

drivers/clocksource/moxart_timer.c

@@ -21,6 +21,7 @@
 #include <linux/io.h>
 #include <linux/clocksource.h>
 #include <linux/bitops.h>
+#include <linux/slab.h>
 
 #define TIMER1_BASE		0x00
 #define TIMER2_BASE		0x10
@@ -36,97 +37,129 @@
 #define TIMER_INTR_MASK		0x38
 
 /*
- * TIMER_CR flags:
+ * Moxart TIMER_CR flags:
  *
- * TIMEREG_CR_*_CLOCK	0: PCLK, 1: EXT1CLK
- * TIMEREG_CR_*_INT	overflow interrupt enable bit
+ * MOXART_CR_*_CLOCK	0: PCLK, 1: EXT1CLK
+ * MOXART_CR_*_INT	overflow interrupt enable bit
  */
-#define TIMEREG_CR_1_ENABLE	BIT(0)
-#define TIMEREG_CR_1_CLOCK	BIT(1)
-#define TIMEREG_CR_1_INT	BIT(2)
-#define TIMEREG_CR_2_ENABLE	BIT(3)
-#define TIMEREG_CR_2_CLOCK	BIT(4)
-#define TIMEREG_CR_2_INT	BIT(5)
-#define TIMEREG_CR_3_ENABLE	BIT(6)
-#define TIMEREG_CR_3_CLOCK	BIT(7)
-#define TIMEREG_CR_3_INT	BIT(8)
-#define TIMEREG_CR_COUNT_UP	BIT(9)
-
-#define TIMER1_ENABLE		(TIMEREG_CR_2_ENABLE | TIMEREG_CR_1_ENABLE)
-#define TIMER1_DISABLE		(TIMEREG_CR_2_ENABLE)
-
-static void __iomem *base;
-static unsigned int clock_count_per_tick;
+#define MOXART_CR_1_ENABLE	BIT(0)
+#define MOXART_CR_1_CLOCK	BIT(1)
+#define MOXART_CR_1_INT	BIT(2)
+#define MOXART_CR_2_ENABLE	BIT(3)
+#define MOXART_CR_2_CLOCK	BIT(4)
+#define MOXART_CR_2_INT	BIT(5)
+#define MOXART_CR_3_ENABLE	BIT(6)
+#define MOXART_CR_3_CLOCK	BIT(7)
+#define MOXART_CR_3_INT	BIT(8)
+#define MOXART_CR_COUNT_UP	BIT(9)
+
+#define MOXART_TIMER1_ENABLE	(MOXART_CR_2_ENABLE | MOXART_CR_1_ENABLE)
+#define MOXART_TIMER1_DISABLE	(MOXART_CR_2_ENABLE)
+
+/*
+ * The ASpeed variant of the IP block has a different layout
+ * for the control register
+ */
+#define ASPEED_CR_1_ENABLE	BIT(0)
+#define ASPEED_CR_1_CLOCK	BIT(1)
+#define ASPEED_CR_1_INT		BIT(2)
+#define ASPEED_CR_2_ENABLE	BIT(4)
+#define ASPEED_CR_2_CLOCK	BIT(5)
+#define ASPEED_CR_2_INT		BIT(6)
+#define ASPEED_CR_3_ENABLE	BIT(8)
+#define ASPEED_CR_3_CLOCK	BIT(9)
+#define ASPEED_CR_3_INT		BIT(10)
+
+#define ASPEED_TIMER1_ENABLE   (ASPEED_CR_2_ENABLE | ASPEED_CR_1_ENABLE)
+#define ASPEED_TIMER1_DISABLE  (ASPEED_CR_2_ENABLE)
+
+struct moxart_timer {
+	void __iomem *base;
+	unsigned int t1_disable_val;
+	unsigned int t1_enable_val;
+	unsigned int count_per_tick;
+	struct clock_event_device clkevt;
+};
+
+static inline struct moxart_timer *to_moxart(struct clock_event_device *evt)
+{
+	return container_of(evt, struct moxart_timer, clkevt);
+}
+
+static inline void moxart_disable(struct clock_event_device *evt)
+{
+	struct moxart_timer *timer = to_moxart(evt);
+
+	writel(timer->t1_disable_val, timer->base + TIMER_CR);
+}
+
+static inline void moxart_enable(struct clock_event_device *evt)
+{
+	struct moxart_timer *timer = to_moxart(evt);
+
+	writel(timer->t1_enable_val, timer->base + TIMER_CR);
+}
 
 static int moxart_shutdown(struct clock_event_device *evt)
 {
-	writel(TIMER1_DISABLE, base + TIMER_CR);
+	moxart_disable(evt);
 	return 0;
 }
 
 static int moxart_set_oneshot(struct clock_event_device *evt)
 {
-	writel(TIMER1_DISABLE, base + TIMER_CR);
-	writel(~0, base + TIMER1_BASE + REG_LOAD);
+	moxart_disable(evt);
+	writel(~0, to_moxart(evt)->base + TIMER1_BASE + REG_LOAD);
 	return 0;
 }
 
 static int moxart_set_periodic(struct clock_event_device *evt)
 {
-	writel(clock_count_per_tick, base + TIMER1_BASE + REG_LOAD);
-	writel(TIMER1_ENABLE, base + TIMER_CR);
+	struct moxart_timer *timer = to_moxart(evt);
+
+	moxart_disable(evt);
+	writel(timer->count_per_tick, timer->base + TIMER1_BASE + REG_LOAD);
+	writel(0, timer->base + TIMER1_BASE + REG_MATCH1);
+	moxart_enable(evt);
 	return 0;
 }
 
 static int moxart_clkevt_next_event(unsigned long cycles,
-				    struct clock_event_device *unused)
+				    struct clock_event_device *evt)
 {
+	struct moxart_timer *timer = to_moxart(evt);
 	u32 u;
 
-	writel(TIMER1_DISABLE, base + TIMER_CR);
+	moxart_disable(evt);
 
-	u = readl(base + TIMER1_BASE + REG_COUNT) - cycles;
-	writel(u, base + TIMER1_BASE + REG_MATCH1);
+	u = readl(timer->base + TIMER1_BASE + REG_COUNT) - cycles;
+	writel(u, timer->base + TIMER1_BASE + REG_MATCH1);
 
-	writel(TIMER1_ENABLE, base + TIMER_CR);
+	moxart_enable(evt);
 
 	return 0;
 }
 
-static struct clock_event_device moxart_clockevent = {
-	.name			= "moxart_timer",
-	.rating			= 200,
-	.features		= CLOCK_EVT_FEAT_PERIODIC |
-				  CLOCK_EVT_FEAT_ONESHOT,
-	.set_state_shutdown	= moxart_shutdown,
-	.set_state_periodic	= moxart_set_periodic,
-	.set_state_oneshot	= moxart_set_oneshot,
-	.tick_resume		= moxart_set_oneshot,
-	.set_next_event		= moxart_clkevt_next_event,
-};
-
 static irqreturn_t moxart_timer_interrupt(int irq, void *dev_id)
 {
 	struct clock_event_device *evt = dev_id;
 	evt->event_handler(evt);
 	return IRQ_HANDLED;
 }
 
-static struct irqaction moxart_timer_irq = {
-	.name		= "moxart-timer",
-	.flags		= IRQF_TIMER,
-	.handler	= moxart_timer_interrupt,
-	.dev_id		= &moxart_clockevent,
-};
-
 static int __init moxart_timer_init(struct device_node *node)
 {
 	int ret, irq;
 	unsigned long pclk;
 	struct clk *clk;
+	struct moxart_timer *timer;
+
+	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
+	if (!timer)
+		return -ENOMEM;
 
-	base = of_iomap(node, 0);
-	if (!base) {
+	timer->base = of_iomap(node, 0);
+	if (!timer->base) {
 		pr_err("%s: of_iomap failed\n", node->full_name);
 		return -ENXIO;
 	}
@@ -137,12 +170,6 @@ static int __init moxart_timer_init(struct device_node *node)
 		return -EINVAL;
 	}
 
-	ret = setup_irq(irq, &moxart_timer_irq);
-	if (ret) {
-		pr_err("%s: setup_irq failed\n", node->full_name);
-		return ret;
-	}
-
 	clk = of_clk_get(node, 0);
 	if (IS_ERR(clk))  {
 		pr_err("%s: of_clk_get failed\n", node->full_name);
@@ -151,31 +178,69 @@ static int __init moxart_timer_init(struct device_node *node)
 
 	pclk = clk_get_rate(clk);
 
-	ret = clocksource_mmio_init(base + TIMER2_BASE + REG_COUNT,
+	if (of_device_is_compatible(node, "moxa,moxart-timer")) {
+		timer->t1_enable_val = MOXART_TIMER1_ENABLE;
+		timer->t1_disable_val = MOXART_TIMER1_DISABLE;
+	} else if (of_device_is_compatible(node, "aspeed,ast2400-timer")) {
+		timer->t1_enable_val = ASPEED_TIMER1_ENABLE;
+		timer->t1_disable_val = ASPEED_TIMER1_DISABLE;
+	} else {
+		pr_err("%s: unknown platform\n", node->full_name);
+		return -EINVAL;
+	}
+
+	timer->count_per_tick = DIV_ROUND_CLOSEST(pclk, HZ);
+
+	timer->clkevt.name = node->name;
+	timer->clkevt.rating = 200;
+	timer->clkevt.features = CLOCK_EVT_FEAT_PERIODIC |
+					CLOCK_EVT_FEAT_ONESHOT;
+	timer->clkevt.set_state_shutdown = moxart_shutdown;
+	timer->clkevt.set_state_periodic = moxart_set_periodic;
+	timer->clkevt.set_state_oneshot = moxart_set_oneshot;
+	timer->clkevt.tick_resume = moxart_set_oneshot;
+	timer->clkevt.set_next_event = moxart_clkevt_next_event;
+	timer->clkevt.cpumask = cpumask_of(0);
+	timer->clkevt.irq = irq;
+
+	ret = clocksource_mmio_init(timer->base + TIMER2_BASE + REG_COUNT,
 				    "moxart_timer", pclk, 200, 32,
 				    clocksource_mmio_readl_down);
 	if (ret) {
 		pr_err("%s: clocksource_mmio_init failed\n", node->full_name);
 		return ret;
 	}
 
-	clock_count_per_tick = DIV_ROUND_CLOSEST(pclk, HZ);
+	ret = request_irq(irq, moxart_timer_interrupt, IRQF_TIMER,
+			  node->name, &timer->clkevt);
+	if (ret) {
+		pr_err("%s: setup_irq failed\n", node->full_name);
+		return ret;
+	}
 
-	writel(~0, base + TIMER2_BASE + REG_LOAD);
-	writel(TIMEREG_CR_2_ENABLE, base + TIMER_CR);
+	/* Clear match registers */
+	writel(0, timer->base + TIMER1_BASE + REG_MATCH1);
+	writel(0, timer->base + TIMER1_BASE + REG_MATCH2);
+	writel(0, timer->base + TIMER2_BASE + REG_MATCH1);
+	writel(0, timer->base + TIMER2_BASE + REG_MATCH2);
 
-	moxart_clockevent.cpumask = cpumask_of(0);
-	moxart_clockevent.irq = irq;
+	/*
+	 * Start timer 2 rolling as our main wall clock source, keep timer 1
+	 * disabled
+	 */
+	writel(0, timer->base + TIMER_CR);
+	writel(~0, timer->base + TIMER2_BASE + REG_LOAD);
+	writel(timer->t1_disable_val, timer->base + TIMER_CR);
 
 	/*
 	 * documentation is not publicly available:
 	 * min_delta / max_delta obtained by trial-and-error,
 	 * max_delta 0xfffffffe should be ok because count
 	 * register size is u32
 	 */
-	clockevents_config_and_register(&moxart_clockevent, pclk,
-					0x4, 0xfffffffe);
+	clockevents_config_and_register(&timer->clkevt, pclk, 0x4, 0xfffffffe);
 
 	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(moxart, "moxa,moxart-timer", moxart_timer_init);
+CLOCKSOURCE_OF_DECLARE(aspeed, "aspeed,ast2400-timer", moxart_timer_init);