v4.19.13 snapshot.
diff --git a/drivers/clocksource/timer-atlas7.c b/drivers/clocksource/timer-atlas7.c
new file mode 100644
index 0000000..62c4bbc
--- /dev/null
+++ b/drivers/clocksource/timer-atlas7.c
@@ -0,0 +1,286 @@
+/*
+ * System timer for CSR SiRFprimaII
+ *
+ * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/cpu.h>
+#include <linux/bitops.h>
+#include <linux/irq.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/sched_clock.h>
+
+#define SIRFSOC_TIMER_32COUNTER_0_CTRL			0x0000
+#define SIRFSOC_TIMER_32COUNTER_1_CTRL			0x0004
+#define SIRFSOC_TIMER_MATCH_0				0x0018
+#define SIRFSOC_TIMER_MATCH_1				0x001c
+#define SIRFSOC_TIMER_COUNTER_0				0x0048
+#define SIRFSOC_TIMER_COUNTER_1				0x004c
+#define SIRFSOC_TIMER_INTR_STATUS			0x0060
+#define SIRFSOC_TIMER_WATCHDOG_EN			0x0064
+#define SIRFSOC_TIMER_64COUNTER_CTRL			0x0068
+#define SIRFSOC_TIMER_64COUNTER_LO			0x006c
+#define SIRFSOC_TIMER_64COUNTER_HI			0x0070
+#define SIRFSOC_TIMER_64COUNTER_LOAD_LO			0x0074
+#define SIRFSOC_TIMER_64COUNTER_LOAD_HI			0x0078
+#define SIRFSOC_TIMER_64COUNTER_RLATCHED_LO		0x007c
+#define SIRFSOC_TIMER_64COUNTER_RLATCHED_HI		0x0080
+
+#define SIRFSOC_TIMER_REG_CNT 6
+
+static unsigned long atlas7_timer_rate;
+
+static const u32 sirfsoc_timer_reg_list[SIRFSOC_TIMER_REG_CNT] = {
+	SIRFSOC_TIMER_WATCHDOG_EN,
+	SIRFSOC_TIMER_32COUNTER_0_CTRL,
+	SIRFSOC_TIMER_32COUNTER_1_CTRL,
+	SIRFSOC_TIMER_64COUNTER_CTRL,
+	SIRFSOC_TIMER_64COUNTER_RLATCHED_LO,
+	SIRFSOC_TIMER_64COUNTER_RLATCHED_HI,
+};
+
+static u32 sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT];
+
+static void __iomem *sirfsoc_timer_base;
+
+/* disable count and interrupt */
+static inline void sirfsoc_timer_count_disable(int idx)
+{
+	writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx) & ~0x7,
+		sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx);
+}
+
+/* enable count and interrupt */
+static inline void sirfsoc_timer_count_enable(int idx)
+{
+	writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx) | 0x3,
+		sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx);
+}
+
+/* timer interrupt handler */
+static irqreturn_t sirfsoc_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *ce = dev_id;
+	int cpu = smp_processor_id();
+
+	/* clear timer interrupt */
+	writel_relaxed(BIT(cpu), sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS);
+
+	if (clockevent_state_oneshot(ce))
+		sirfsoc_timer_count_disable(cpu);
+
+	ce->event_handler(ce);
+
+	return IRQ_HANDLED;
+}
+
+/* read 64-bit timer counter */
+static u64 sirfsoc_timer_read(struct clocksource *cs)
+{
+	u64 cycles;
+
+	writel_relaxed((readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) |
+			BIT(0)) & ~BIT(1), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
+
+	cycles = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_RLATCHED_HI);
+	cycles = (cycles << 32) | readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_RLATCHED_LO);
+
+	return cycles;
+}
+
+static int sirfsoc_timer_set_next_event(unsigned long delta,
+	struct clock_event_device *ce)
+{
+	int cpu = smp_processor_id();
+
+	/* disable timer first, then modify the related registers */
+	sirfsoc_timer_count_disable(cpu);
+
+	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_0 +
+		4 * cpu);
+	writel_relaxed(delta, sirfsoc_timer_base + SIRFSOC_TIMER_MATCH_0 +
+		4 * cpu);
+
+	/* enable the tick */
+	sirfsoc_timer_count_enable(cpu);
+
+	return 0;
+}
+
+/* Oneshot is enabled in set_next_event */
+static int sirfsoc_timer_shutdown(struct clock_event_device *evt)
+{
+	sirfsoc_timer_count_disable(smp_processor_id());
+	return 0;
+}
+
+static void sirfsoc_clocksource_suspend(struct clocksource *cs)
+{
+	int i;
+
+	for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++)
+		sirfsoc_timer_reg_val[i] = readl_relaxed(sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
+}
+
+static void sirfsoc_clocksource_resume(struct clocksource *cs)
+{
+	int i;
+
+	for (i = 0; i < SIRFSOC_TIMER_REG_CNT - 2; i++)
+		writel_relaxed(sirfsoc_timer_reg_val[i], sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
+
+	writel_relaxed(sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT - 2],
+		sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_LO);
+	writel_relaxed(sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT - 1],
+		sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_HI);
+
+	writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) |
+		BIT(1) | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
+}
+
+static struct clock_event_device __percpu *sirfsoc_clockevent;
+
+static struct clocksource sirfsoc_clocksource = {
+	.name = "sirfsoc_clocksource",
+	.rating = 200,
+	.mask = CLOCKSOURCE_MASK(64),
+	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
+	.read = sirfsoc_timer_read,
+	.suspend = sirfsoc_clocksource_suspend,
+	.resume = sirfsoc_clocksource_resume,
+};
+
+static struct irqaction sirfsoc_timer_irq = {
+	.name = "sirfsoc_timer0",
+	.flags = IRQF_TIMER | IRQF_NOBALANCING,
+	.handler = sirfsoc_timer_interrupt,
+};
+
+static struct irqaction sirfsoc_timer1_irq = {
+	.name = "sirfsoc_timer1",
+	.flags = IRQF_TIMER | IRQF_NOBALANCING,
+	.handler = sirfsoc_timer_interrupt,
+};
+
+static int sirfsoc_local_timer_starting_cpu(unsigned int cpu)
+{
+	struct clock_event_device *ce = per_cpu_ptr(sirfsoc_clockevent, cpu);
+	struct irqaction *action;
+
+	if (cpu == 0)
+		action = &sirfsoc_timer_irq;
+	else
+		action = &sirfsoc_timer1_irq;
+
+	ce->irq = action->irq;
+	ce->name = "local_timer";
+	ce->features = CLOCK_EVT_FEAT_ONESHOT;
+	ce->rating = 200;
+	ce->set_state_shutdown = sirfsoc_timer_shutdown;
+	ce->set_state_oneshot = sirfsoc_timer_shutdown;
+	ce->tick_resume = sirfsoc_timer_shutdown;
+	ce->set_next_event = sirfsoc_timer_set_next_event;
+	clockevents_calc_mult_shift(ce, atlas7_timer_rate, 60);
+	ce->max_delta_ns = clockevent_delta2ns(-2, ce);
+	ce->max_delta_ticks = (unsigned long)-2;
+	ce->min_delta_ns = clockevent_delta2ns(2, ce);
+	ce->min_delta_ticks = 2;
+	ce->cpumask = cpumask_of(cpu);
+
+	action->dev_id = ce;
+	BUG_ON(setup_irq(ce->irq, action));
+	irq_force_affinity(action->irq, cpumask_of(cpu));
+
+	clockevents_register_device(ce);
+	return 0;
+}
+
+static int sirfsoc_local_timer_dying_cpu(unsigned int cpu)
+{
+	sirfsoc_timer_count_disable(1);
+
+	if (cpu == 0)
+		remove_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq);
+	else
+		remove_irq(sirfsoc_timer1_irq.irq, &sirfsoc_timer1_irq);
+	return 0;
+}
+
+static int __init sirfsoc_clockevent_init(void)
+{
+	sirfsoc_clockevent = alloc_percpu(struct clock_event_device);
+	BUG_ON(!sirfsoc_clockevent);
+
+	/* Install and invoke hotplug callbacks */
+	return cpuhp_setup_state(CPUHP_AP_MARCO_TIMER_STARTING,
+				 "clockevents/marco:starting",
+				 sirfsoc_local_timer_starting_cpu,
+				 sirfsoc_local_timer_dying_cpu);
+}
+
+/* initialize the kernel jiffy timer source */
+static int __init sirfsoc_atlas7_timer_init(struct device_node *np)
+{
+	struct clk *clk;
+
+	clk = of_clk_get(np, 0);
+	BUG_ON(IS_ERR(clk));
+
+	BUG_ON(clk_prepare_enable(clk));
+
+	atlas7_timer_rate = clk_get_rate(clk);
+
+	/* timer dividers: 0, not divided */
+	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
+	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL);
+	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_1_CTRL);
+
+	/* Initialize timer counters to 0 */
+	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_LO);
+	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_HI);
+	writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) |
+		BIT(1) | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
+	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_0);
+	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_1);
+
+	/* Clear all interrupts */
+	writel_relaxed(0xFFFF, sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS);
+
+	BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, atlas7_timer_rate));
+
+	return sirfsoc_clockevent_init();
+}
+
+static int __init sirfsoc_of_timer_init(struct device_node *np)
+{
+	sirfsoc_timer_base = of_iomap(np, 0);
+	if (!sirfsoc_timer_base) {
+		pr_err("unable to map timer cpu registers\n");
+		return -ENXIO;
+	}
+
+	sirfsoc_timer_irq.irq = irq_of_parse_and_map(np, 0);
+	if (!sirfsoc_timer_irq.irq) {
+		pr_err("No irq passed for timer0 via DT\n");
+		return -EINVAL;
+	}
+
+	sirfsoc_timer1_irq.irq = irq_of_parse_and_map(np, 1);
+	if (!sirfsoc_timer1_irq.irq) {
+		pr_err("No irq passed for timer1 via DT\n");
+		return -EINVAL;
+	}
+
+	return sirfsoc_atlas7_timer_init(np);
+}
+TIMER_OF_DECLARE(sirfsoc_atlas7_timer, "sirf,atlas7-tick", sirfsoc_of_timer_init);