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 #include <asm/pdcpat.h> 20 21 static u64 cr16_clock_freq; 22 static unsigned long clocktick; 23 24 int time_keeper_id; /* CPU used for timekeeping */ 25 26 static DEFINE_PER_CPU(struct clock_event_device, parisc_clockevent_device); 27 28 static void parisc_event_handler(struct clock_event_device *dev) 29 { 30 } 31 32 static int parisc_timer_next_event(unsigned long delta, struct clock_event_device *evt) 33 { 34 unsigned long new_cr16; 35 36 new_cr16 = mfctl(16) + delta; 37 mtctl(new_cr16, 16); 38 39 return 0; 40 } 41 42 irqreturn_t timer_interrupt(int irq, void *data) 43 { 44 struct clock_event_device *cd; 45 int cpu = smp_processor_id(); 46 47 cd = &per_cpu(parisc_clockevent_device, cpu); 48 49 if (clockevent_state_periodic(cd)) 50 parisc_timer_next_event(clocktick, cd); 51 52 if (clockevent_state_periodic(cd) || clockevent_state_oneshot(cd)) 53 cd->event_handler(cd); 54 55 return IRQ_HANDLED; 56 } 57 58 static int parisc_set_state_oneshot(struct clock_event_device *evt) 59 { 60 parisc_timer_next_event(clocktick, evt); 61 62 return 0; 63 } 64 65 static int parisc_set_state_periodic(struct clock_event_device *evt) 66 { 67 parisc_timer_next_event(clocktick, evt); 68 69 return 0; 70 } 71 72 static int parisc_set_state_shutdown(struct clock_event_device *evt) 73 { 74 return 0; 75 } 76 77 void parisc_clockevent_init(void) 78 { 79 unsigned int cpu = smp_processor_id(); 80 unsigned long min_delta = 0x600; /* XXX */ 81 unsigned long max_delta = (1UL << (BITS_PER_LONG - 1)); 82 struct clock_event_device *cd; 83 84 cd = &per_cpu(parisc_clockevent_device, cpu); 85 86 cd->name = "cr16_clockevent"; 87 cd->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC | 88 CLOCK_EVT_FEAT_PERCPU; 89 90 cd->irq = TIMER_IRQ; 91 cd->rating = 320; 92 cd->cpumask = cpumask_of(cpu); 93 cd->set_state_oneshot = parisc_set_state_oneshot; 94 cd->set_state_oneshot_stopped = parisc_set_state_shutdown; 95 cd->set_state_periodic = parisc_set_state_periodic; 96 cd->set_state_shutdown = parisc_set_state_shutdown; 97 cd->set_next_event = parisc_timer_next_event; 98 cd->event_handler = parisc_event_handler; 99 100 clockevents_config_and_register(cd, cr16_clock_freq, min_delta, max_delta); 101 } 102 103 static void parisc_find_64bit_counter(void) 104 { 105 #ifdef CONFIG_64BIT 106 uint64_t *pclock; 107 unsigned long freq, unique; 108 int ret; 109 110 ret = pdc_pat_pd_get_platform_counter(&pclock, &freq, &unique); 111 if (ret == PDC_OK) 112 pr_info("64-bit counter found at %px, freq: %lu, unique: %lu\n", 113 pclock, freq, unique); 114 else 115 pr_info("64-bit counter not found.\n"); 116 #endif 117 } 118 119 unsigned long notrace profile_pc(struct pt_regs *regs) 120 { 121 unsigned long pc = instruction_pointer(regs); 122 123 if (regs->gr[0] & PSW_N) 124 pc -= 4; 125 126 #ifdef CONFIG_SMP 127 if (in_lock_functions(pc)) 128 pc = regs->gr[2]; 129 #endif 130 131 return pc; 132 } 133 EXPORT_SYMBOL(profile_pc); 134 135 #if IS_ENABLED(CONFIG_RTC_DRV_GENERIC) 136 static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm) 137 { 138 struct pdc_tod tod_data; 139 140 memset(tm, 0, sizeof(*tm)); 141 if (pdc_tod_read(&tod_data) < 0) 142 return -EOPNOTSUPP; 143 144 /* we treat tod_sec as unsigned, so this can work until year 2106 */ 145 rtc_time64_to_tm(tod_data.tod_sec, tm); 146 return 0; 147 } 148 149 static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm) 150 { 151 time64_t secs = rtc_tm_to_time64(tm); 152 int ret; 153 154 /* hppa has Y2K38 problem: pdc_tod_set() takes an u32 value! */ 155 ret = pdc_tod_set(secs, 0); 156 if (ret != 0) { 157 pr_warn("pdc_tod_set(%lld) returned error %d\n", secs, ret); 158 if (ret == PDC_INVALID_ARG) 159 return -EINVAL; 160 return -EOPNOTSUPP; 161 } 162 163 return 0; 164 } 165 166 static const struct rtc_class_ops rtc_generic_ops = { 167 .read_time = rtc_generic_get_time, 168 .set_time = rtc_generic_set_time, 169 }; 170 171 static int __init rtc_init(void) 172 { 173 struct platform_device *pdev; 174 175 pdev = platform_device_register_data(NULL, "rtc-generic", -1, 176 &rtc_generic_ops, 177 sizeof(rtc_generic_ops)); 178 179 return PTR_ERR_OR_ZERO(pdev); 180 } 181 device_initcall(rtc_init); 182 #endif 183 184 void read_persistent_clock64(struct timespec64 *ts) 185 { 186 static struct pdc_tod tod_data; 187 if (pdc_tod_read(&tod_data) == 0) { 188 ts->tv_sec = tod_data.tod_sec; 189 ts->tv_nsec = tod_data.tod_usec * 1000; 190 } else { 191 printk(KERN_ERR "Error reading tod clock\n"); 192 ts->tv_sec = 0; 193 ts->tv_nsec = 0; 194 } 195 } 196 197 static u64 notrace read_cr16_sched_clock(void) 198 { 199 return get_cycles(); 200 } 201 202 static u64 notrace read_cr16(struct clocksource *cs) 203 { 204 return get_cycles(); 205 } 206 207 static struct clocksource clocksource_cr16 = { 208 .name = "cr16", 209 .rating = 300, 210 .read = read_cr16, 211 .mask = CLOCKSOURCE_MASK(BITS_PER_LONG), 212 .flags = CLOCK_SOURCE_IS_CONTINUOUS | 213 CLOCK_SOURCE_VALID_FOR_HRES | 214 CLOCK_SOURCE_MUST_VERIFY | 215 CLOCK_SOURCE_VERIFY_PERCPU, 216 }; 217 218 219 /* 220 * timer interrupt and sched_clock() initialization 221 */ 222 223 void __init time_init(void) 224 { 225 cr16_clock_freq = 100 * PAGE0->mem_10msec; /* Hz */ 226 clocktick = cr16_clock_freq / HZ; 227 228 /* register as sched_clock source */ 229 sched_clock_register(read_cr16_sched_clock, BITS_PER_LONG, cr16_clock_freq); 230 231 parisc_clockevent_init(); 232 233 /* check for free-running 64-bit platform counter */ 234 parisc_find_64bit_counter(); 235 236 /* register at clocksource framework */ 237 clocksource_register_hz(&clocksource_cr16, cr16_clock_freq); 238 } 239