1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Copyright (C) 2014 ARM Limited
5 */
6
7 #include <linux/clocksource.h>
8 #include <linux/io.h>
9 #include <linux/of.h>
10 #include <linux/of_address.h>
11 #include <linux/sched_clock.h>
12
13 #define SYS_24MHZ 0x05c
14
15 static void __iomem *versatile_sys_24mhz;
16
versatile_sys_24mhz_read(void)17 static u64 notrace versatile_sys_24mhz_read(void)
18 {
19 return readl(versatile_sys_24mhz);
20 }
21
versatile_sched_clock_init(struct device_node * node)22 static int __init versatile_sched_clock_init(struct device_node *node)
23 {
24 void __iomem *base = of_iomap(node, 0);
25
26 of_node_clear_flag(node, OF_POPULATED);
27
28 if (!base)
29 return -ENXIO;
30
31 versatile_sys_24mhz = base + SYS_24MHZ;
32
33 sched_clock_register(versatile_sys_24mhz_read, 32, 24000000);
34
35 return 0;
36 }
37 TIMER_OF_DECLARE(vexpress, "arm,vexpress-sysreg",
38 versatile_sched_clock_init);
39 TIMER_OF_DECLARE(versatile, "arm,versatile-sysreg",
40 versatile_sched_clock_init);
41