1 files changed, 148 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-imx-sysctr.c b/drivers/clocksource/timer-imx-sysctr.c
new file mode 100644
index 000000000..18b90fc56
--- /dev/null
+++ b/drivers/clocksource/timer-imx-sysctr.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// Copyright 2017-2019 NXP
+
+#include <linux/interrupt.h>
+#include <linux/clockchips.h>
+
+#include "timer-of.h"
+
+#define CMP_OFFSET	0x10000
+
+#define CNTCV_LO	0x8
+#define CNTCV_HI	0xc
+#define CMPCV_LO	(CMP_OFFSET + 0x20)
+#define CMPCV_HI	(CMP_OFFSET + 0x24)
+#define CMPCR		(CMP_OFFSET + 0x2c)
+
+#define SYS_CTR_EN		0x1
+#define SYS_CTR_IRQ_MASK	0x2
+
+#define SYS_CTR_CLK_DIV		0x3
+
+static void __iomem *sys_ctr_base;
+static u32 cmpcr;
+
+static void sysctr_timer_enable(bool enable)
+{
+	writel(enable ? cmpcr | SYS_CTR_EN : cmpcr, sys_ctr_base + CMPCR);
+}
+
+static void sysctr_irq_acknowledge(void)
+{
+	/*
+	 * clear the enable bit(EN =0) will clear
+	 * the status bit(ISTAT = 0), then the interrupt
+	 * signal will be negated(acknowledged).
+	 */
+	sysctr_timer_enable(false);
+}
+
+static inline u64 sysctr_read_counter(void)
+{
+	u32 cnt_hi, tmp_hi, cnt_lo;
+
+	do {
+		cnt_hi = readl_relaxed(sys_ctr_base + CNTCV_HI);
+		cnt_lo = readl_relaxed(sys_ctr_base + CNTCV_LO);
+		tmp_hi = readl_relaxed(sys_ctr_base + CNTCV_HI);
+	} while (tmp_hi != cnt_hi);
+
+	return  ((u64) cnt_hi << 32) | cnt_lo;
+}
+
+static int sysctr_set_next_event(unsigned long delta,
+				 struct clock_event_device *evt)
+{
+	u32 cmp_hi, cmp_lo;
+	u64 next;
+
+	sysctr_timer_enable(false);
+
+	next = sysctr_read_counter();
+
+	next += delta;
+
+	cmp_hi = (next >> 32) & 0x00fffff;
+	cmp_lo = next & 0xffffffff;
+
+	writel_relaxed(cmp_hi, sys_ctr_base + CMPCV_HI);
+	writel_relaxed(cmp_lo, sys_ctr_base + CMPCV_LO);
+
+	sysctr_timer_enable(true);
+
+	return 0;
+}
+
+static int sysctr_set_state_oneshot(struct clock_event_device *evt)
+{
+	return 0;
+}
+
+static int sysctr_set_state_shutdown(struct clock_event_device *evt)
+{
+	sysctr_timer_enable(false);
+
+	return 0;
+}
+
+static irqreturn_t sysctr_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = dev_id;
+
+	sysctr_irq_acknowledge();
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static struct timer_of to_sysctr = {
+	.flags = TIMER_OF_IRQ | TIMER_OF_CLOCK | TIMER_OF_BASE,
+	.clkevt = {
+		.name			= "i.MX system counter timer",
+		.features		= CLOCK_EVT_FEAT_ONESHOT |
+						CLOCK_EVT_FEAT_DYNIRQ,
+		.set_state_oneshot	= sysctr_set_state_oneshot,
+		.set_next_event		= sysctr_set_next_event,
+		.set_state_shutdown	= sysctr_set_state_shutdown,
+		.rating			= 200,
+	},
+	.of_irq = {
+		.handler		= sysctr_timer_interrupt,
+		.flags			= IRQF_TIMER | IRQF_IRQPOLL,
+	},
+	.of_clk = {
+		.name = "per",
+	},
+};
+
+static void __init sysctr_clockevent_init(void)
+{
+	to_sysctr.clkevt.cpumask = cpumask_of(0);
+
+	clockevents_config_and_register(&to_sysctr.clkevt,
+					timer_of_rate(&to_sysctr),
+					0xff, 0x7fffffff);
+}
+
+static int __init sysctr_timer_init(struct device_node *np)
+{
+	int ret = 0;
+
+	ret = timer_of_init(np, &to_sysctr);
+	if (ret)
+		return ret;
+
+	/* system counter clock is divided by 3 internally */
+	to_sysctr.of_clk.rate /= SYS_CTR_CLK_DIV;
+
+	sys_ctr_base = timer_of_base(&to_sysctr);
+	cmpcr = readl(sys_ctr_base + CMPCR);
+	cmpcr &= ~SYS_CTR_EN;
+
+	sysctr_clockevent_init();
+
+	return 0;
+}
+TIMER_OF_DECLARE(sysctr_timer, "nxp,sysctr-timer", sysctr_timer_init);