drivers/ptp/ptp_clock.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * PTP 1588 clock support
0004  *
0005  * Copyright (C) 2010 OMICRON electronics GmbH
0006  */
0007 #include <linux/idr.h>
0008 #include <linux/device.h>
0009 #include <linux/err.h>
0010 #include <linux/init.h>
0011 #include <linux/kernel.h>
0012 #include <linux/module.h>
0013 #include <linux/posix-clock.h>
0014 #include <linux/pps_kernel.h>
0015 #include <linux/slab.h>
0016 #include <linux/syscalls.h>
0017 #include <linux/uaccess.h>
0018 #include <uapi/linux/sched/types.h>
0019
0020 #include "ptp_private.h"
0021
0022 #define PTP_MAX_ALARMS 4
0023 #define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT)
0024 #define PTP_PPS_EVENT PPS_CAPTUREASSERT
0025 #define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC)
0026
0027 struct class *ptp_class;
0028
0029 /* private globals */
0030
0031 static dev_t ptp_devt;
0032
0033 static DEFINE_IDA(ptp_clocks_map);
0034
0035 /* time stamp event queue operations */
0036
0037 static inline int queue_free(struct timestamp_event_queue *q)
0038 {
0039     return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
0040 }
0041
0042 static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
0043                        struct ptp_clock_event *src)
0044 {
0045     struct ptp_extts_event *dst;
0046     unsigned long flags;
0047     s64 seconds;
0048     u32 remainder;
0049
0050     seconds = div_u64_rem(src->timestamp, 1000000000, &remainder);
0051
0052     spin_lock_irqsave(&queue->lock, flags);
0053
0054     dst = &queue->buf[queue->tail];
0055     dst->index = src->index;
0056     dst->t.sec = seconds;
0057     dst->t.nsec = remainder;
0058
0059     if (!queue_free(queue))
0060         queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
0061
0062     queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS;
0063
0064     spin_unlock_irqrestore(&queue->lock, flags);
0065 }
0066
0067 /* posix clock implementation */
0068
0069 static int ptp_clock_getres(struct posix_clock *pc, struct timespec64 *tp)
0070 {
0071     tp->tv_sec = 0;
0072     tp->tv_nsec = 1;
0073     return 0;
0074 }
0075
0076 static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp)
0077 {
0078     struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
0079
0080     if (ptp_clock_freerun(ptp)) {
0081         pr_err("ptp: physical clock is free running\n");
0082         return -EBUSY;
0083     }
0084
0085     return  ptp->info->settime64(ptp->info, tp);
0086 }
0087
0088 static int ptp_clock_gettime(struct posix_clock *pc, struct timespec64 *tp)
0089 {
0090     struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
0091     int err;
0092
0093     if (ptp->info->gettimex64)
0094         err = ptp->info->gettimex64(ptp->info, tp, NULL);
0095     else
0096         err = ptp->info->gettime64(ptp->info, tp);
0097     return err;
0098 }
0099
0100 static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx)
0101 {
0102     struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
0103     struct ptp_clock_info *ops;
0104     int err = -EOPNOTSUPP;
0105
0106     if (ptp_clock_freerun(ptp)) {
0107         pr_err("ptp: physical clock is free running\n");
0108         return -EBUSY;
0109     }
0110
0111     ops = ptp->info;
0112
0113     if (tx->modes & ADJ_SETOFFSET) {
0114         struct timespec64 ts;
0115         ktime_t kt;
0116         s64 delta;
0117
0118         ts.tv_sec  = tx->time.tv_sec;
0119         ts.tv_nsec = tx->time.tv_usec;
0120
0121         if (!(tx->modes & ADJ_NANO))
0122             ts.tv_nsec *= 1000;
0123
0124         if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
0125             return -EINVAL;
0126
0127         kt = timespec64_to_ktime(ts);
0128         delta = ktime_to_ns(kt);
0129         err = ops->adjtime(ops, delta);
0130     } else if (tx->modes & ADJ_FREQUENCY) {
0131         long ppb = scaled_ppm_to_ppb(tx->freq);
0132         if (ppb > ops->max_adj || ppb < -ops->max_adj)
0133             return -ERANGE;
0134         if (ops->adjfine)
0135             err = ops->adjfine(ops, tx->freq);
0136         else
0137             err = ops->adjfreq(ops, ppb);
0138         ptp->dialed_frequency = tx->freq;
0139     } else if (tx->modes & ADJ_OFFSET) {
0140         if (ops->adjphase) {
0141             s32 offset = tx->offset;
0142
0143             if (!(tx->modes & ADJ_NANO))
0144                 offset *= NSEC_PER_USEC;
0145
0146             err = ops->adjphase(ops, offset);
0147         }
0148     } else if (tx->modes == 0) {
0149         tx->freq = ptp->dialed_frequency;
0150         err = 0;
0151     }
0152
0153     return err;
0154 }
0155
0156 static struct posix_clock_operations ptp_clock_ops = {
0157     .owner      = THIS_MODULE,
0158     .clock_adjtime  = ptp_clock_adjtime,
0159     .clock_gettime  = ptp_clock_gettime,
0160     .clock_getres   = ptp_clock_getres,
0161     .clock_settime  = ptp_clock_settime,
0162     .ioctl      = ptp_ioctl,
0163     .open       = ptp_open,
0164     .poll       = ptp_poll,
0165     .read       = ptp_read,
0166 };
0167
0168 static void ptp_clock_release(struct device *dev)
0169 {
0170     struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev);
0171
0172     ptp_cleanup_pin_groups(ptp);
0173     kfree(ptp->vclock_index);
0174     mutex_destroy(&ptp->tsevq_mux);
0175     mutex_destroy(&ptp->pincfg_mux);
0176     mutex_destroy(&ptp->n_vclocks_mux);
0177     ida_simple_remove(&ptp_clocks_map, ptp->index);
0178     kfree(ptp);
0179 }
0180
0181 static int ptp_getcycles64(struct ptp_clock_info *info, struct timespec64 *ts)
0182 {
0183     if (info->getcyclesx64)
0184         return info->getcyclesx64(info, ts, NULL);
0185     else
0186         return info->gettime64(info, ts);
0187 }
0188
0189 static void ptp_aux_kworker(struct kthread_work *work)
0190 {
0191     struct ptp_clock *ptp = container_of(work, struct ptp_clock,
0192                          aux_work.work);
0193     struct ptp_clock_info *info = ptp->info;
0194     long delay;
0195
0196     delay = info->do_aux_work(info);
0197
0198     if (delay >= 0)
0199         kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay);
0200 }
0201
0202 /* public interface */
0203
0204 struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
0205                      struct device *parent)
0206 {
0207     struct ptp_clock *ptp;
0208     int err = 0, index, major = MAJOR(ptp_devt);
0209     size_t size;
0210
0211     if (info->n_alarm > PTP_MAX_ALARMS)
0212         return ERR_PTR(-EINVAL);
0213
0214     /* Initialize a clock structure. */
0215     err = -ENOMEM;
0216     ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
0217     if (ptp == NULL)
0218         goto no_memory;
0219
0220     index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL);
0221     if (index < 0) {
0222         err = index;
0223         goto no_slot;
0224     }
0225
0226     ptp->clock.ops = ptp_clock_ops;
0227     ptp->info = info;
0228     ptp->devid = MKDEV(major, index);
0229     ptp->index = index;
0230     spin_lock_init(&ptp->tsevq.lock);
0231     mutex_init(&ptp->tsevq_mux);
0232     mutex_init(&ptp->pincfg_mux);
0233     mutex_init(&ptp->n_vclocks_mux);
0234     init_waitqueue_head(&ptp->tsev_wq);
0235
0236     if (ptp->info->getcycles64 || ptp->info->getcyclesx64) {
0237         ptp->has_cycles = true;
0238         if (!ptp->info->getcycles64 && ptp->info->getcyclesx64)
0239             ptp->info->getcycles64 = ptp_getcycles64;
0240     } else {
0241         /* Free running cycle counter not supported, use time. */
0242         ptp->info->getcycles64 = ptp_getcycles64;
0243
0244         if (ptp->info->gettimex64)
0245             ptp->info->getcyclesx64 = ptp->info->gettimex64;
0246
0247         if (ptp->info->getcrosststamp)
0248             ptp->info->getcrosscycles = ptp->info->getcrosststamp;
0249     }
0250
0251     if (ptp->info->do_aux_work) {
0252         kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker);
0253         ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index);
0254         if (IS_ERR(ptp->kworker)) {
0255             err = PTR_ERR(ptp->kworker);
0256             pr_err("failed to create ptp aux_worker %d\n", err);
0257             goto kworker_err;
0258         }
0259     }
0260
0261     /* PTP virtual clock is being registered under physical clock */
0262     if (parent && parent->class && parent->class->name &&
0263         strcmp(parent->class->name, "ptp") == 0)
0264         ptp->is_virtual_clock = true;
0265
0266     if (!ptp->is_virtual_clock) {
0267         ptp->max_vclocks = PTP_DEFAULT_MAX_VCLOCKS;
0268
0269         size = sizeof(int) * ptp->max_vclocks;
0270         ptp->vclock_index = kzalloc(size, GFP_KERNEL);
0271         if (!ptp->vclock_index) {
0272             err = -ENOMEM;
0273             goto no_mem_for_vclocks;
0274         }
0275     }
0276
0277     err = ptp_populate_pin_groups(ptp);
0278     if (err)
0279         goto no_pin_groups;
0280
0281     /* Register a new PPS source. */
0282     if (info->pps) {
0283         struct pps_source_info pps;
0284         memset(&pps, 0, sizeof(pps));
0285         snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
0286         pps.mode = PTP_PPS_MODE;
0287         pps.owner = info->owner;
0288         ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
0289         if (IS_ERR(ptp->pps_source)) {
0290             err = PTR_ERR(ptp->pps_source);
0291             pr_err("failed to register pps source\n");
0292             goto no_pps;
0293         }
0294         ptp->pps_source->lookup_cookie = ptp;
0295     }
0296
0297     /* Initialize a new device of our class in our clock structure. */
0298     device_initialize(&ptp->dev);
0299     ptp->dev.devt = ptp->devid;
0300     ptp->dev.class = ptp_class;
0301     ptp->dev.parent = parent;
0302     ptp->dev.groups = ptp->pin_attr_groups;
0303     ptp->dev.release = ptp_clock_release;
0304     dev_set_drvdata(&ptp->dev, ptp);
0305     dev_set_name(&ptp->dev, "ptp%d", ptp->index);
0306
0307     /* Create a posix clock and link it to the device. */
0308     err = posix_clock_register(&ptp->clock, &ptp->dev);
0309     if (err) {
0310         if (ptp->pps_source)
0311             pps_unregister_source(ptp->pps_source);
0312
0313         if (ptp->kworker)
0314             kthread_destroy_worker(ptp->kworker);
0315
0316         put_device(&ptp->dev);
0317
0318         pr_err("failed to create posix clock\n");
0319         return ERR_PTR(err);
0320     }
0321
0322     return ptp;
0323
0324 no_pps:
0325     ptp_cleanup_pin_groups(ptp);
0326 no_pin_groups:
0327     kfree(ptp->vclock_index);
0328 no_mem_for_vclocks:
0329     if (ptp->kworker)
0330         kthread_destroy_worker(ptp->kworker);
0331 kworker_err:
0332     mutex_destroy(&ptp->tsevq_mux);
0333     mutex_destroy(&ptp->pincfg_mux);
0334     mutex_destroy(&ptp->n_vclocks_mux);
0335     ida_simple_remove(&ptp_clocks_map, index);
0336 no_slot:
0337     kfree(ptp);
0338 no_memory:
0339     return ERR_PTR(err);
0340 }
0341 EXPORT_SYMBOL(ptp_clock_register);
0342
0343 static int unregister_vclock(struct device *dev, void *data)
0344 {
0345     struct ptp_clock *ptp = dev_get_drvdata(dev);
0346
0347     ptp_vclock_unregister(info_to_vclock(ptp->info));
0348     return 0;
0349 }
0350
0351 int ptp_clock_unregister(struct ptp_clock *ptp)
0352 {
0353     if (ptp_vclock_in_use(ptp)) {
0354         device_for_each_child(&ptp->dev, NULL, unregister_vclock);
0355     }
0356
0357     ptp->defunct = 1;
0358     wake_up_interruptible(&ptp->tsev_wq);
0359
0360     if (ptp->kworker) {
0361         kthread_cancel_delayed_work_sync(&ptp->aux_work);
0362         kthread_destroy_worker(ptp->kworker);
0363     }
0364
0365     /* Release the clock's resources. */
0366     if (ptp->pps_source)
0367         pps_unregister_source(ptp->pps_source);
0368
0369     posix_clock_unregister(&ptp->clock);
0370
0371     return 0;
0372 }
0373 EXPORT_SYMBOL(ptp_clock_unregister);
0374
0375 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
0376 {
0377     struct pps_event_time evt;
0378
0379     switch (event->type) {
0380
0381     case PTP_CLOCK_ALARM:
0382         break;
0383
0384     case PTP_CLOCK_EXTTS:
0385         enqueue_external_timestamp(&ptp->tsevq, event);
0386         wake_up_interruptible(&ptp->tsev_wq);
0387         break;
0388
0389     case PTP_CLOCK_PPS:
0390         pps_get_ts(&evt);
0391         pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
0392         break;
0393
0394     case PTP_CLOCK_PPSUSR:
0395         pps_event(ptp->pps_source, &event->pps_times,
0396               PTP_PPS_EVENT, NULL);
0397         break;
0398     }
0399 }
0400 EXPORT_SYMBOL(ptp_clock_event);
0401
0402 int ptp_clock_index(struct ptp_clock *ptp)
0403 {
0404     return ptp->index;
0405 }
0406 EXPORT_SYMBOL(ptp_clock_index);
0407
0408 int ptp_find_pin(struct ptp_clock *ptp,
0409          enum ptp_pin_function func, unsigned int chan)
0410 {
0411     struct ptp_pin_desc *pin = NULL;
0412     int i;
0413
0414     for (i = 0; i < ptp->info->n_pins; i++) {
0415         if (ptp->info->pin_config[i].func == func &&
0416             ptp->info->pin_config[i].chan == chan) {
0417             pin = &ptp->info->pin_config[i];
0418             break;
0419         }
0420     }
0421
0422     return pin ? i : -1;
0423 }
0424 EXPORT_SYMBOL(ptp_find_pin);
0425
0426 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
0427               enum ptp_pin_function func, unsigned int chan)
0428 {
0429     int result;
0430
0431     mutex_lock(&ptp->pincfg_mux);
0432
0433     result = ptp_find_pin(ptp, func, chan);
0434
0435     mutex_unlock(&ptp->pincfg_mux);
0436
0437     return result;
0438 }
0439 EXPORT_SYMBOL(ptp_find_pin_unlocked);
0440
0441 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay)
0442 {
0443     return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay);
0444 }
0445 EXPORT_SYMBOL(ptp_schedule_worker);
0446
0447 void ptp_cancel_worker_sync(struct ptp_clock *ptp)
0448 {
0449     kthread_cancel_delayed_work_sync(&ptp->aux_work);
0450 }
0451 EXPORT_SYMBOL(ptp_cancel_worker_sync);
0452
0453 /* module operations */
0454
0455 static void __exit ptp_exit(void)
0456 {
0457     class_destroy(ptp_class);
0458     unregister_chrdev_region(ptp_devt, MINORMASK + 1);
0459     ida_destroy(&ptp_clocks_map);
0460 }
0461
0462 static int __init ptp_init(void)
0463 {
0464     int err;
0465
0466     ptp_class = class_create(THIS_MODULE, "ptp");
0467     if (IS_ERR(ptp_class)) {
0468         pr_err("ptp: failed to allocate class\n");
0469         return PTR_ERR(ptp_class);
0470     }
0471
0472     err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
0473     if (err < 0) {
0474         pr_err("ptp: failed to allocate device region\n");
0475         goto no_region;
0476     }
0477
0478     ptp_class->dev_groups = ptp_groups;
0479     pr_info("PTP clock support registered\n");
0480     return 0;
0481
0482 no_region:
0483     class_destroy(ptp_class);
0484     return err;
0485 }
0486
0487 subsys_initcall(ptp_init);
0488 module_exit(ptp_exit);
0489
0490 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
0491 MODULE_DESCRIPTION("PTP clocks support");
0492 MODULE_LICENSE("GPL");