1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/clocksource.h>
3*4882a593Smuzhiyun #include <linux/sched_clock.h>
4*4882a593Smuzhiyun #include <linux/of_address.h>
5*4882a593Smuzhiyun #include <linux/printk.h>
6*4882a593Smuzhiyun #include <linux/delay.h>
7*4882a593Smuzhiyun #include <linux/init.h>
8*4882a593Smuzhiyun #include <linux/clk.h>
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun static void __iomem *xtal_in_cnt;
11*4882a593Smuzhiyun static struct delay_timer delay_timer;
12*4882a593Smuzhiyun
read_xtal_counter(void)13*4882a593Smuzhiyun static unsigned long notrace read_xtal_counter(void)
14*4882a593Smuzhiyun {
15*4882a593Smuzhiyun return readl_relaxed(xtal_in_cnt);
16*4882a593Smuzhiyun }
17*4882a593Smuzhiyun
read_sched_clock(void)18*4882a593Smuzhiyun static u64 notrace read_sched_clock(void)
19*4882a593Smuzhiyun {
20*4882a593Smuzhiyun return read_xtal_counter();
21*4882a593Smuzhiyun }
22*4882a593Smuzhiyun
tango_clocksource_init(struct device_node * np)23*4882a593Smuzhiyun static int __init tango_clocksource_init(struct device_node *np)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun struct clk *clk;
26*4882a593Smuzhiyun int xtal_freq, ret;
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun xtal_in_cnt = of_iomap(np, 0);
29*4882a593Smuzhiyun if (xtal_in_cnt == NULL) {
30*4882a593Smuzhiyun pr_err("%pOF: invalid address\n", np);
31*4882a593Smuzhiyun return -ENXIO;
32*4882a593Smuzhiyun }
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun clk = of_clk_get(np, 0);
35*4882a593Smuzhiyun if (IS_ERR(clk)) {
36*4882a593Smuzhiyun pr_err("%pOF: invalid clock\n", np);
37*4882a593Smuzhiyun return PTR_ERR(clk);
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun xtal_freq = clk_get_rate(clk);
41*4882a593Smuzhiyun delay_timer.freq = xtal_freq;
42*4882a593Smuzhiyun delay_timer.read_current_timer = read_xtal_counter;
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun ret = clocksource_mmio_init(xtal_in_cnt, "tango-xtal", xtal_freq, 350,
45*4882a593Smuzhiyun 32, clocksource_mmio_readl_up);
46*4882a593Smuzhiyun if (ret) {
47*4882a593Smuzhiyun pr_err("%pOF: registration failed\n", np);
48*4882a593Smuzhiyun return ret;
49*4882a593Smuzhiyun }
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun sched_clock_register(read_sched_clock, 32, xtal_freq);
52*4882a593Smuzhiyun register_current_timer_delay(&delay_timer);
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun return 0;
55*4882a593Smuzhiyun }
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun TIMER_OF_DECLARE(tango, "sigma,tick-counter", tango_clocksource_init);
58