Merge branch 'linus' into timers/core

Make sure the upstream fixes are applied before adding further
modifications.

4 files changed, 335 insertions, 27 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index b4ac7cf..51d7865f 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -143,6 +143,11 @@ config ATMEL_PIT
 	select CLKSRC_OF if OF
 	def_bool SOC_AT91SAM9 || SOC_SAMA5
 
+config ATMEL_ST
+	bool
+	select CLKSRC_OF
+	select MFD_SYSCON
+
 config CLKSRC_METAG_GENERIC
 	def_bool y if METAG
 	help
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 752d5c7..5b85f6a 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -1,5 +1,6 @@
 obj-$(CONFIG_CLKSRC_OF)	+= clksrc-of.o
 obj-$(CONFIG_ATMEL_PIT)		+= timer-atmel-pit.o
+obj-$(CONFIG_ATMEL_ST)		+= timer-atmel-st.o
 obj-$(CONFIG_ATMEL_TCB_CLKSRC)	+= tcb_clksrc.o
 obj-$(CONFIG_X86_PM_TIMER)	+= acpi_pm.o
 obj-$(CONFIG_SCx200HR_TIMER)	+= scx200_hrt.o
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 2664696..0aa135d 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -22,6 +22,7 @@
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/sched_clock.h>
+#include <linux/acpi.h>
 
 #include <asm/arch_timer.h>
 #include <asm/virt.h>
@@ -371,8 +372,12 @@ arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np)
 	if (arch_timer_rate)
 		return;
 
-	/* Try to determine the frequency from the device tree or CNTFRQ */
-	if (of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
+	/*
+	 * Try to determine the frequency from the device tree or CNTFRQ,
+	 * if ACPI is enabled, get the frequency from CNTFRQ ONLY.
+	 */
+	if (!acpi_disabled ||
+	    of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
 		if (cntbase)
 			arch_timer_rate = readl_relaxed(cntbase + CNTFRQ);
 		else
@@ -691,28 +696,8 @@ static void __init arch_timer_common_init(void)
 	arch_timer_arch_init();
 }
 
-static void __init arch_timer_init(struct device_node *np)
+static void __init arch_timer_init(void)
 {
-	int i;
-
-	if (arch_timers_present & ARCH_CP15_TIMER) {
-		pr_warn("arch_timer: multiple nodes in dt, skipping\n");
-		return;
-	}
-
-	arch_timers_present |= ARCH_CP15_TIMER;
-	for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
-		arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
-	arch_timer_detect_rate(NULL, np);
-
-	/*
-	 * If we cannot rely on firmware initializing the timer registers then
-	 * we should use the physical timers instead.
-	 */
-	if (IS_ENABLED(CONFIG_ARM) &&
-	    of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
-			arch_timer_use_virtual = false;
-
 	/*
 	 * If HYP mode is available, we know that the physical timer
 	 * has been configured to be accessible from PL1. Use it, so
@@ -731,13 +716,39 @@ static void __init arch_timer_init(struct device_node *np)
 		}
 	}
 
-	arch_timer_c3stop = !of_property_read_bool(np, "always-on");
-
 	arch_timer_register();
 	arch_timer_common_init();
 }
-CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_init);
-CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_init);
+
+static void __init arch_timer_of_init(struct device_node *np)
+{
+	int i;
+
+	if (arch_timers_present & ARCH_CP15_TIMER) {
+		pr_warn("arch_timer: multiple nodes in dt, skipping\n");
+		return;
+	}
+
+	arch_timers_present |= ARCH_CP15_TIMER;
+	for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
+		arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
+
+	arch_timer_detect_rate(NULL, np);
+
+	arch_timer_c3stop = !of_property_read_bool(np, "always-on");
+
+	/*
+	 * If we cannot rely on firmware initializing the timer registers then
+	 * we should use the physical timers instead.
+	 */
+	if (IS_ENABLED(CONFIG_ARM) &&
+	    of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
+			arch_timer_use_virtual = false;
+
+	arch_timer_init();
+}
+CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init);
+CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);
 
 static void __init arch_timer_mem_init(struct device_node *np)
 {
@@ -804,3 +815,70 @@ static void __init arch_timer_mem_init(struct device_node *np)
 }
 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
 		       arch_timer_mem_init);
+
+#ifdef CONFIG_ACPI
+static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags)
+{
+	int trigger, polarity;
+
+	if (!interrupt)
+		return 0;
+
+	trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
+			: ACPI_LEVEL_SENSITIVE;
+
+	polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
+			: ACPI_ACTIVE_HIGH;
+
+	return acpi_register_gsi(NULL, interrupt, trigger, polarity);
+}
+
+/* Initialize per-processor generic timer */
+static int __init arch_timer_acpi_init(struct acpi_table_header *table)
+{
+	struct acpi_table_gtdt *gtdt;
+
+	if (arch_timers_present & ARCH_CP15_TIMER) {
+		pr_warn("arch_timer: already initialized, skipping\n");
+		return -EINVAL;
+	}
+
+	gtdt = container_of(table, struct acpi_table_gtdt, header);
+
+	arch_timers_present |= ARCH_CP15_TIMER;
+
+	arch_timer_ppi[PHYS_SECURE_PPI] =
+		map_generic_timer_interrupt(gtdt->secure_el1_interrupt,
+		gtdt->secure_el1_flags);
+
+	arch_timer_ppi[PHYS_NONSECURE_PPI] =
+		map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt,
+		gtdt->non_secure_el1_flags);
+
+	arch_timer_ppi[VIRT_PPI] =
+		map_generic_timer_interrupt(gtdt->virtual_timer_interrupt,
+		gtdt->virtual_timer_flags);
+
+	arch_timer_ppi[HYP_PPI] =
+		map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt,
+		gtdt->non_secure_el2_flags);
+
+	/* Get the frequency from CNTFRQ */
+	arch_timer_detect_rate(NULL, NULL);
+
+	/* Always-on capability */
+	arch_timer_c3stop = !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
+
+	arch_timer_init();
+	return 0;
+}
+
+/* Initialize all the generic timers presented in GTDT */
+void __init acpi_generic_timer_init(void)
+{
+	if (acpi_disabled)
+		return;
+
+	acpi_table_parse(ACPI_SIG_GTDT, arch_timer_acpi_init);
+}
+#endif
diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c
new file mode 100644
index 0000000..1692e17
--- /dev/null
+++ b/drivers/clocksource/timer-atmel-st.c
@@ -0,0 +1,224 @@
+/*
+ * linux/arch/arm/mach-at91/at91rm9200_time.c
+ *
+ *  Copyright (C) 2003 SAN People
+ *  Copyright (C) 2003 ATMEL
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/clockchips.h>
+#include <linux/export.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-st.h>
+#include <linux/of_irq.h>
+#include <linux/regmap.h>
+
+static unsigned long last_crtr;
+static u32 irqmask;
+static struct clock_event_device clkevt;
+static struct regmap *regmap_st;
+
+#define AT91_SLOW_CLOCK		32768
+#define RM9200_TIMER_LATCH	((AT91_SLOW_CLOCK + HZ/2) / HZ)
+
+/*
+ * The ST_CRTR is updated asynchronously to the master clock ... but
+ * the updates as seen by the CPU don't seem to be strictly monotonic.
+ * Waiting until we read the same value twice avoids glitching.
+ */
+static inline unsigned long read_CRTR(void)
+{
+	unsigned int x1, x2;
+
+	regmap_read(regmap_st, AT91_ST_CRTR, &x1);
+	do {
+		regmap_read(regmap_st, AT91_ST_CRTR, &x2);
+		if (x1 == x2)
+			break;
+		x1 = x2;
+	} while (1);
+	return x1;
+}
+
+/*
+ * IRQ handler for the timer.
+ */
+static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id)
+{
+	u32 sr;
+
+	regmap_read(regmap_st, AT91_ST_SR, &sr);
+	sr &= irqmask;
+
+	/*
+	 * irqs should be disabled here, but as the irq is shared they are only
+	 * guaranteed to be off if the timer irq is registered first.
+	 */
+	WARN_ON_ONCE(!irqs_disabled());
+
+	/* simulate "oneshot" timer with alarm */
+	if (sr & AT91_ST_ALMS) {
+		clkevt.event_handler(&clkevt);
+		return IRQ_HANDLED;
+	}
+
+	/* periodic mode should handle delayed ticks */
+	if (sr & AT91_ST_PITS) {
+		u32	crtr = read_CRTR();
+
+		while (((crtr - last_crtr) & AT91_ST_CRTV) >= RM9200_TIMER_LATCH) {
+			last_crtr += RM9200_TIMER_LATCH;
+			clkevt.event_handler(&clkevt);
+		}
+		return IRQ_HANDLED;
+	}
+
+	/* this irq is shared ... */
+	return IRQ_NONE;
+}
+
+static cycle_t read_clk32k(struct clocksource *cs)
+{
+	return read_CRTR();
+}
+
+static struct clocksource clk32k = {
+	.name		= "32k_counter",
+	.rating		= 150,
+	.read		= read_clk32k,
+	.mask		= CLOCKSOURCE_MASK(20),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void
+clkevt32k_mode(enum clock_event_mode mode, struct clock_event_device *dev)
+{
+	unsigned int val;
+
+	/* Disable and flush pending timer interrupts */
+	regmap_write(regmap_st, AT91_ST_IDR, AT91_ST_PITS | AT91_ST_ALMS);
+	regmap_read(regmap_st, AT91_ST_SR, &val);
+
+	last_crtr = read_CRTR();
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		/* PIT for periodic irqs; fixed rate of 1/HZ */
+		irqmask = AT91_ST_PITS;
+		regmap_write(regmap_st, AT91_ST_PIMR, RM9200_TIMER_LATCH);
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+		/* ALM for oneshot irqs, set by next_event()
+		 * before 32 seconds have passed
+		 */
+		irqmask = AT91_ST_ALMS;
+		regmap_write(regmap_st, AT91_ST_RTAR, last_crtr);
+		break;
+	case CLOCK_EVT_MODE_SHUTDOWN:
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_RESUME:
+		irqmask = 0;
+		break;
+	}
+	regmap_write(regmap_st, AT91_ST_IER, irqmask);
+}
+
+static int
+clkevt32k_next_event(unsigned long delta, struct clock_event_device *dev)
+{
+	u32		alm;
+	int		status = 0;
+	unsigned int	val;
+
+	BUG_ON(delta < 2);
+
+	/* The alarm IRQ uses absolute time (now+delta), not the relative
+	 * time (delta) in our calling convention.  Like all clockevents
+	 * using such "match" hardware, we have a race to defend against.
+	 *
+	 * Our defense here is to have set up the clockevent device so the
+	 * delta is at least two.  That way we never end up writing RTAR
+	 * with the value then held in CRTR ... which would mean the match
+	 * wouldn't trigger until 32 seconds later, after CRTR wraps.
+	 */
+	alm = read_CRTR();
+
+	/* Cancel any pending alarm; flush any pending IRQ */
+	regmap_write(regmap_st, AT91_ST_RTAR, alm);
+	regmap_read(regmap_st, AT91_ST_SR, &val);
+
+	/* Schedule alarm by writing RTAR. */
+	alm += delta;
+	regmap_write(regmap_st, AT91_ST_RTAR, alm);
+
+	return status;
+}
+
+static struct clock_event_device clkevt = {
+	.name		= "at91_tick",
+	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.rating		= 150,
+	.set_next_event	= clkevt32k_next_event,
+	.set_mode	= clkevt32k_mode,
+};
+
+/*
+ * ST (system timer) module supports both clockevents and clocksource.
+ */
+static void __init atmel_st_timer_init(struct device_node *node)
+{
+	unsigned int val;
+	int irq, ret;
+
+	regmap_st = syscon_node_to_regmap(node);
+	if (IS_ERR(regmap_st))
+		panic(pr_fmt("Unable to get regmap\n"));
+
+	/* Disable all timer interrupts, and clear any pending ones */
+	regmap_write(regmap_st, AT91_ST_IDR,
+		AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS);
+	regmap_read(regmap_st, AT91_ST_SR, &val);
+
+	/* Get the interrupts property */
+	irq  = irq_of_parse_and_map(node, 0);
+	if (!irq)
+		panic(pr_fmt("Unable to get IRQ from DT\n"));
+
+	/* Make IRQs happen for the system timer */
+	ret = request_irq(irq, at91rm9200_timer_interrupt,
+			  IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
+			  "at91_tick", regmap_st);
+	if (ret)
+		panic(pr_fmt("Unable to setup IRQ\n"));
+
+	/* The 32KiHz "Slow Clock" (tick every 30517.58 nanoseconds) is used
+	 * directly for the clocksource and all clockevents, after adjusting
+	 * its prescaler from the 1 Hz default.
+	 */
+	regmap_write(regmap_st, AT91_ST_RTMR, 1);
+
+	/* Setup timer clockevent, with minimum of two ticks (important!!) */
+	clkevt.cpumask = cpumask_of(0);
+	clockevents_config_and_register(&clkevt, AT91_SLOW_CLOCK,
+					2, AT91_ST_ALMV);
+
+	/* register clocksource */
+	clocksource_register_hz(&clk32k, AT91_SLOW_CLOCK);
+}
+CLOCKSOURCE_OF_DECLARE(atmel_st_timer, "atmel,at91rm9200-st",
+		       atmel_st_timer_init);