1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Common time service routines for parisc machines.
4 * based on arch/loongarch/kernel/time.c
5 *
6 * Copyright (C) 2024 Helge Deller <deller@gmx.de>
7 */
8 #include <linux/clockchips.h>
9 #include <linux/delay.h>
10 #include <linux/export.h>
11 #include <linux/init.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/sched_clock.h>
15 #include <linux/spinlock.h>
16 #include <linux/rtc.h>
17 #include <linux/platform_device.h>
18 #include <asm/processor.h>
19
20 static u64 cr16_clock_freq;
21 static unsigned long clocktick;
22
23 int time_keeper_id; /* CPU used for timekeeping */
24
25 static DEFINE_PER_CPU(struct clock_event_device, parisc_clockevent_device);
26
parisc_event_handler(struct clock_event_device * dev)27 static void parisc_event_handler(struct clock_event_device *dev)
28 {
29 }
30
parisc_timer_next_event(unsigned long delta,struct clock_event_device * evt)31 static int parisc_timer_next_event(unsigned long delta, struct clock_event_device *evt)
32 {
33 unsigned long new_cr16;
34
35 new_cr16 = mfctl(16) + delta;
36 mtctl(new_cr16, 16);
37
38 return 0;
39 }
40
timer_interrupt(int irq,void * data)41 irqreturn_t timer_interrupt(int irq, void *data)
42 {
43 struct clock_event_device *cd;
44 int cpu = smp_processor_id();
45
46 cd = &per_cpu(parisc_clockevent_device, cpu);
47
48 if (clockevent_state_periodic(cd))
49 parisc_timer_next_event(clocktick, cd);
50
51 if (clockevent_state_periodic(cd) || clockevent_state_oneshot(cd))
52 cd->event_handler(cd);
53
54 return IRQ_HANDLED;
55 }
56
parisc_set_state_oneshot(struct clock_event_device * evt)57 static int parisc_set_state_oneshot(struct clock_event_device *evt)
58 {
59 parisc_timer_next_event(clocktick, evt);
60
61 return 0;
62 }
63
parisc_set_state_periodic(struct clock_event_device * evt)64 static int parisc_set_state_periodic(struct clock_event_device *evt)
65 {
66 parisc_timer_next_event(clocktick, evt);
67
68 return 0;
69 }
70
parisc_set_state_shutdown(struct clock_event_device * evt)71 static int parisc_set_state_shutdown(struct clock_event_device *evt)
72 {
73 return 0;
74 }
75
parisc_clockevent_init(void)76 void parisc_clockevent_init(void)
77 {
78 unsigned int cpu = smp_processor_id();
79 unsigned long min_delta = 0x600; /* XXX */
80 unsigned long max_delta = (1UL << (BITS_PER_LONG - 1));
81 struct clock_event_device *cd;
82
83 cd = &per_cpu(parisc_clockevent_device, cpu);
84
85 cd->name = "cr16_clockevent";
86 cd->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC |
87 CLOCK_EVT_FEAT_PERCPU;
88
89 cd->irq = TIMER_IRQ;
90 cd->rating = 320;
91 cd->cpumask = cpumask_of(cpu);
92 cd->set_state_oneshot = parisc_set_state_oneshot;
93 cd->set_state_oneshot_stopped = parisc_set_state_shutdown;
94 cd->set_state_periodic = parisc_set_state_periodic;
95 cd->set_state_shutdown = parisc_set_state_shutdown;
96 cd->set_next_event = parisc_timer_next_event;
97 cd->event_handler = parisc_event_handler;
98
99 clockevents_config_and_register(cd, cr16_clock_freq, min_delta, max_delta);
100 }
101
profile_pc(struct pt_regs * regs)102 unsigned long notrace profile_pc(struct pt_regs *regs)
103 {
104 unsigned long pc = instruction_pointer(regs);
105
106 if (regs->gr[0] & PSW_N)
107 pc -= 4;
108
109 #ifdef CONFIG_SMP
110 if (in_lock_functions(pc))
111 pc = regs->gr[2];
112 #endif
113
114 return pc;
115 }
116 EXPORT_SYMBOL(profile_pc);
117
118 #if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
rtc_generic_get_time(struct device * dev,struct rtc_time * tm)119 static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
120 {
121 struct pdc_tod tod_data;
122
123 memset(tm, 0, sizeof(*tm));
124 if (pdc_tod_read(&tod_data) < 0)
125 return -EOPNOTSUPP;
126
127 /* we treat tod_sec as unsigned, so this can work until year 2106 */
128 rtc_time64_to_tm(tod_data.tod_sec, tm);
129 return 0;
130 }
131
rtc_generic_set_time(struct device * dev,struct rtc_time * tm)132 static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
133 {
134 time64_t secs = rtc_tm_to_time64(tm);
135 int ret;
136
137 /* hppa has Y2K38 problem: pdc_tod_set() takes an u32 value! */
138 ret = pdc_tod_set(secs, 0);
139 if (ret != 0) {
140 pr_warn("pdc_tod_set(%lld) returned error %d\n", secs, ret);
141 if (ret == PDC_INVALID_ARG)
142 return -EINVAL;
143 return -EOPNOTSUPP;
144 }
145
146 return 0;
147 }
148
149 static const struct rtc_class_ops rtc_generic_ops = {
150 .read_time = rtc_generic_get_time,
151 .set_time = rtc_generic_set_time,
152 };
153
rtc_init(void)154 static int __init rtc_init(void)
155 {
156 struct platform_device *pdev;
157
158 pdev = platform_device_register_data(NULL, "rtc-generic", -1,
159 &rtc_generic_ops,
160 sizeof(rtc_generic_ops));
161
162 return PTR_ERR_OR_ZERO(pdev);
163 }
164 device_initcall(rtc_init);
165 #endif
166
read_persistent_clock64(struct timespec64 * ts)167 void read_persistent_clock64(struct timespec64 *ts)
168 {
169 static struct pdc_tod tod_data;
170 if (pdc_tod_read(&tod_data) == 0) {
171 ts->tv_sec = tod_data.tod_sec;
172 ts->tv_nsec = tod_data.tod_usec * 1000;
173 } else {
174 printk(KERN_ERR "Error reading tod clock\n");
175 ts->tv_sec = 0;
176 ts->tv_nsec = 0;
177 }
178 }
179
read_cr16_sched_clock(void)180 static u64 notrace read_cr16_sched_clock(void)
181 {
182 return get_cycles();
183 }
184
read_cr16(struct clocksource * cs)185 static u64 notrace read_cr16(struct clocksource *cs)
186 {
187 return get_cycles();
188 }
189
190 static struct clocksource clocksource_cr16 = {
191 .name = "cr16",
192 .rating = 300,
193 .read = read_cr16,
194 .mask = CLOCKSOURCE_MASK(BITS_PER_LONG),
195 .flags = CLOCK_SOURCE_IS_CONTINUOUS |
196 CLOCK_SOURCE_VALID_FOR_HRES |
197 CLOCK_SOURCE_MUST_VERIFY |
198 CLOCK_SOURCE_VERIFY_PERCPU,
199 };
200
201
202 /*
203 * timer interrupt and sched_clock() initialization
204 */
205
time_init(void)206 void __init time_init(void)
207 {
208 cr16_clock_freq = 100 * PAGE0->mem_10msec; /* Hz */
209 clocktick = cr16_clock_freq / HZ;
210
211 /* register as sched_clock source */
212 sched_clock_register(read_cr16_sched_clock, BITS_PER_LONG, cr16_clock_freq);
213
214 parisc_clockevent_init();
215
216 /* register at clocksource framework */
217 clocksource_register_hz(&clocksource_cr16, cr16_clock_freq);
218 }
219