1#include <linux/clocksource.h>
 2#include <linux/sched_clock.h>
 3#include <linux/of_address.h>
 4#include <linux/printk.h>
 5#include <linux/delay.h>
 6#include <linux/init.h>
 7#include <linux/clk.h>
 8
 9static void __iomem *xtal_in_cnt;
10static struct delay_timer delay_timer;
11
12static unsigned long notrace read_xtal_counter(void)
13{
14	return readl_relaxed(xtal_in_cnt);
15}
16
17static u64 notrace read_sched_clock(void)
18{
19	return read_xtal_counter();
20}
21
22static void __init tango_clocksource_init(struct device_node *np)
23{
24	struct clk *clk;
25	int xtal_freq, ret;
26
27	xtal_in_cnt = of_iomap(np, 0);
28	if (xtal_in_cnt == NULL) {
29		pr_err("%s: invalid address\n", np->full_name);
30		return;
31	}
32
33	clk = of_clk_get(np, 0);
34	if (IS_ERR(clk)) {
35		pr_err("%s: invalid clock\n", np->full_name);
36		return;
37	}
38
39	xtal_freq = clk_get_rate(clk);
40	delay_timer.freq = xtal_freq;
41	delay_timer.read_current_timer = read_xtal_counter;
42
43	ret = clocksource_mmio_init(xtal_in_cnt, "tango-xtal", xtal_freq, 350,
44				    32, clocksource_mmio_readl_up);
45	if (ret) {
46		pr_err("%s: registration failed\n", np->full_name);
47		return;
48	}
49
50	sched_clock_register(read_sched_clock, 32, xtal_freq);
51	register_current_timer_delay(&delay_timer);
52}
53
54CLOCKSOURCE_OF_DECLARE(tango, "sigma,tick-counter", tango_clocksource_init);