1 files changed, 57 insertions, 0 deletions
diff --git a/drivers/clocksource/tango_xtal.c b/drivers/clocksource/tango_xtal.c
new file mode 100644
index 000000000..3f94e454e
--- /dev/null
+++ b/drivers/clocksource/tango_xtal.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/clocksource.h>
+#include <linux/sched_clock.h>
+#include <linux/of_address.h>
+#include <linux/printk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+
+static void __iomem *xtal_in_cnt;
+static struct delay_timer delay_timer;
+
+static unsigned long notrace read_xtal_counter(void)
+{
+	return readl_relaxed(xtal_in_cnt);
+}
+
+static u64 notrace read_sched_clock(void)
+{
+	return read_xtal_counter();
+}
+
+static int __init tango_clocksource_init(struct device_node *np)
+{
+	struct clk *clk;
+	int xtal_freq, ret;
+
+	xtal_in_cnt = of_iomap(np, 0);
+	if (xtal_in_cnt == NULL) {
+		pr_err("%pOF: invalid address\n", np);
+		return -ENXIO;
+	}
+
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		pr_err("%pOF: invalid clock\n", np);
+		return PTR_ERR(clk);
+	}
+
+	xtal_freq = clk_get_rate(clk);
+	delay_timer.freq = xtal_freq;
+	delay_timer.read_current_timer = read_xtal_counter;
+
+	ret = clocksource_mmio_init(xtal_in_cnt, "tango-xtal", xtal_freq, 350,
+				    32, clocksource_mmio_readl_up);
+	if (ret) {
+		pr_err("%pOF: registration failed\n", np);
+		return ret;
+	}
+
+	sched_clock_register(read_sched_clock, 32, xtal_freq);
+	register_current_timer_delay(&delay_timer);
+
+	return 0;
+}
+
+TIMER_OF_DECLARE(tango, "sigma,tick-counter", tango_clocksource_init);