/* * PTP 1588 clock support * * Copyright (C) 2010 OMICRON electronics GmbH * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/idr.h> #include <linux/device.h> #include <linux/err.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/posix-clock.h> #include <linux/pps_kernel.h> #include <linux/slab.h> #include <linux/syscalls.h> #include <linux/uaccess.h> #include "ptp_private.h" #define PTP_MAX_ALARMS 4 #define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT) #define PTP_PPS_EVENT PPS_CAPTUREASSERT #define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC) /* private globals */ static dev_t ptp_devt; static struct class *ptp_class; static DEFINE_IDA(ptp_clocks_map); /* time stamp event queue operations */ static inline int queue_free(struct timestamp_event_queue *q) { return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1; } static void enqueue_external_timestamp(struct timestamp_event_queue *queue, struct ptp_clock_event *src) { struct ptp_extts_event *dst; unsigned long flags; s64 seconds; u32 remainder; seconds = div_u64_rem(src->timestamp, 1000000000, &remainder); spin_lock_irqsave(&queue->lock, flags); dst = &queue->buf[queue->tail]; dst->index = src->index; dst->t.sec = seconds; dst->t.nsec = remainder; if (!queue_free(queue)) queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS; queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS; spin_unlock_irqrestore(&queue->lock, flags); } static s32 scaled_ppm_to_ppb(long ppm) { /* * The 'freq' field in the 'struct timex' is in parts per * million, but with a 16 bit binary fractional field. * * We want to calculate * * ppb = scaled_ppm * 1000 / 2^16 * * which simplifies to * * ppb = scaled_ppm * 125 / 2^13 */ s64 ppb = 1 + ppm; ppb *= 125; ppb >>= 13; return (s32) ppb; } /* posix clock implementation */ static int ptp_clock_getres(struct posix_clock *pc, struct timespec *tp) { tp->tv_sec = 0; tp->tv_nsec = 1; return 0; } static int ptp_clock_settime(struct posix_clock *pc, const struct timespec *tp) { struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); return ptp->info->settime(ptp->info, tp); } static int ptp_clock_gettime(struct posix_clock *pc, struct timespec *tp) { struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); return ptp->info->gettime(ptp->info, tp); } static int ptp_clock_adjtime(struct posix_clock *pc, struct timex *tx) { struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); struct ptp_clock_info *ops; int err = -EOPNOTSUPP; ops = ptp->info; if (tx->modes & ADJ_SETOFFSET) { struct timespec ts; ktime_t kt; s64 delta; ts.tv_sec = tx->time.tv_sec; ts.tv_nsec = tx->time.tv_usec; if (!(tx->modes & ADJ_NANO)) ts.tv_nsec *= 1000; if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC) return -EINVAL; kt = timespec_to_ktime(ts); delta = ktime_to_ns(kt); err = ops->adjtime(ops, delta); } else if (tx->modes & ADJ_FREQUENCY) { err = ops->adjfreq(ops, scaled_ppm_to_ppb(tx->freq)); ptp->dialed_frequency = tx->freq; } else if (tx->modes == 0) { tx->freq = ptp->dialed_frequency; err = 0; } return err; } static struct posix_clock_operations ptp_clock_ops = { .owner = THIS_MODULE, .clock_adjtime = ptp_clock_adjtime, .clock_gettime = ptp_clock_gettime, .clock_getres = ptp_clock_getres, .clock_settime = ptp_clock_settime, .ioctl = ptp_ioctl, .open = ptp_open, .poll = ptp_poll, .read = ptp_read, }; static void delete_ptp_clock(struct posix_clock *pc) { struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); mutex_destroy(&ptp->tsevq_mux); ida_simple_remove(&ptp_clocks_map, ptp->index); kfree(ptp); } /* public interface */ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, struct device *parent) { struct ptp_clock *ptp; int err = 0, index, major = MAJOR(ptp_devt); if (info->n_alarm > PTP_MAX_ALARMS) return ERR_PTR(-EINVAL); /* Initialize a clock structure. */ err = -ENOMEM; ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL); if (ptp == NULL) goto no_memory; index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL); if (index < 0) { err = index; goto no_slot; } ptp->clock.ops = ptp_clock_ops; ptp->clock.release = delete_ptp_clock; ptp->info = info; ptp->devid = MKDEV(major, index); ptp->index = index; spin_lock_init(&ptp->tsevq.lock); mutex_init(&ptp->tsevq_mux); init_waitqueue_head(&ptp->tsev_wq); /* Create a new device in our class. */ ptp->dev = device_create(ptp_class, parent, ptp->devid, ptp, "ptp%d", ptp->index); if (IS_ERR(ptp->dev)) goto no_device; dev_set_drvdata(ptp->dev, ptp); err = ptp_populate_sysfs(ptp); if (err) goto no_sysfs; /* Register a new PPS source. */ if (info->pps) { struct pps_source_info pps; memset(&pps, 0, sizeof(pps)); snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index); pps.mode = PTP_PPS_MODE; pps.owner = info->owner; ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS); if (!ptp->pps_source) { pr_err("failed to register pps source\n"); goto no_pps; } } /* Create a posix clock. */ err = posix_clock_register(&ptp->clock, ptp->devid); if (err) { pr_err("failed to create posix clock\n"); goto no_clock; } return ptp; no_clock: if (ptp->pps_source) pps_unregister_source(ptp->pps_source); no_pps: ptp_cleanup_sysfs(ptp); no_sysfs: device_destroy(ptp_class, ptp->devid); no_device: mutex_destroy(&ptp->tsevq_mux); no_slot: kfree(ptp); no_memory: return ERR_PTR(err); } EXPORT_SYMBOL(ptp_clock_register); int ptp_clock_unregister(struct ptp_clock *ptp) { ptp->defunct = 1; wake_up_interruptible(&ptp->tsev_wq); /* Release the clock's resources. */ if (ptp->pps_source) pps_unregister_source(ptp->pps_source); ptp_cleanup_sysfs(ptp); device_destroy(ptp_class, ptp->devid); posix_clock_unregister(&ptp->clock); return 0; } EXPORT_SYMBOL(ptp_clock_unregister); void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event) { struct pps_event_time evt; switch (event->type) { case PTP_CLOCK_ALARM: break; case PTP_CLOCK_EXTTS: enqueue_external_timestamp(&ptp->tsevq, event); wake_up_interruptible(&ptp->tsev_wq); break; case PTP_CLOCK_PPS: pps_get_ts(&evt); pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL); break; case PTP_CLOCK_PPSUSR: pps_event(ptp->pps_source, &event->pps_times, PTP_PPS_EVENT, NULL); break; } } EXPORT_SYMBOL(ptp_clock_event); int ptp_clock_index(struct ptp_clock *ptp) { return ptp->index; } EXPORT_SYMBOL(ptp_clock_index); /* module operations */ static void __exit ptp_exit(void) { class_destroy(ptp_class); unregister_chrdev_region(ptp_devt, MINORMASK + 1); ida_destroy(&ptp_clocks_map); } static int __init ptp_init(void) { int err; ptp_class = class_create(THIS_MODULE, "ptp"); if (IS_ERR(ptp_class)) { pr_err("ptp: failed to allocate class\n"); return PTR_ERR(ptp_class); } err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp"); if (err < 0) { pr_err("ptp: failed to allocate device region\n"); goto no_region; } ptp_class->dev_attrs = ptp_dev_attrs; pr_info("PTP clock support registered\n"); return 0; no_region: class_destroy(ptp_class); return err; } subsys_initcall(ptp_init); module_exit(ptp_exit); MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>"); MODULE_DESCRIPTION("PTP clocks support"); MODULE_LICENSE("GPL");