1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/module.h>
4 #include <linux/time.h>
5 #include <linux/errno.h>
6 #include <linux/timex.h>
7 #include <linux/clocksource.h>
10 /* IBM Summit (EXA) Cyclone counter code*/
11 #define CYCLONE_CBAR_ADDR 0xFEB00CD0
12 #define CYCLONE_PMCC_OFFSET 0x51A0
13 #define CYCLONE_MPMC_OFFSET 0x51D0
14 #define CYCLONE_MPCS_OFFSET 0x51A8
15 #define CYCLONE_TIMER_FREQ 100000000
18 void __init cyclone_setup(void)
23 static void __iomem *cyclone_mc;
25 static u64 read_cyclone(struct clocksource *cs)
27 return (u64)readq((void __iomem *)cyclone_mc);
30 static struct clocksource clocksource_cyclone = {
34 .mask = (1LL << 40) - 1,
35 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
38 int __init init_cyclone_clock(void)
41 u64 base; /* saved cyclone base address */
42 u64 offset; /* offset from pageaddr to cyclone_timer register */
44 u32 __iomem *cyclone_timer; /* Cyclone MPMC0 register */
49 printk(KERN_INFO "Summit chipset: Starting Cyclone Counter.\n");
51 /* find base address */
52 offset = (CYCLONE_CBAR_ADDR);
53 reg = ioremap_nocache(offset, sizeof(u64));
55 printk(KERN_ERR "Summit chipset: Could not find valid CBAR"
63 printk(KERN_ERR "Summit chipset: Could not find valid CBAR"
70 offset = (base + CYCLONE_PMCC_OFFSET);
71 reg = ioremap_nocache(offset, sizeof(u64));
73 printk(KERN_ERR "Summit chipset: Could not find valid PMCC"
78 writel(0x00000001,reg);
82 offset = (base + CYCLONE_MPCS_OFFSET);
83 reg = ioremap_nocache(offset, sizeof(u64));
85 printk(KERN_ERR "Summit chipset: Could not find valid MPCS"
90 writel(0x00000001,reg);
93 /* map in cyclone_timer */
94 offset = (base + CYCLONE_MPMC_OFFSET);
95 cyclone_timer = ioremap_nocache(offset, sizeof(u32));
97 printk(KERN_ERR "Summit chipset: Could not find valid MPMC"
103 /*quick test to make sure its ticking*/
105 u32 old = readl(cyclone_timer);
107 while(stall--) barrier();
108 if(readl(cyclone_timer) == old){
109 printk(KERN_ERR "Summit chipset: Counter not counting!"
111 iounmap(cyclone_timer);
112 cyclone_timer = NULL;
117 /* initialize last tick */
118 cyclone_mc = cyclone_timer;
119 clocksource_cyclone.archdata.fsys_mmio = cyclone_timer;
120 clocksource_register_hz(&clocksource_cyclone, CYCLONE_TIMER_FREQ);
125 __initcall(init_cyclone_clock);