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 17 static u64 notrace versatile_sys_24mhz_read(void) 18 { 19 return readl(versatile_sys_24mhz); 20 } 21 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