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438 lines
9.9 KiB
438 lines
9.9 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* PTP 1588 clock support |
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* |
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* Copyright (C) 2010 OMICRON electronics GmbH |
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*/ |
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#include <linux/idr.h> |
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#include <linux/device.h> |
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#include <linux/err.h> |
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/posix-clock.h> |
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#include <linux/pps_kernel.h> |
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#include <linux/slab.h> |
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#include <linux/syscalls.h> |
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#include <linux/uaccess.h> |
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#include <uapi/linux/sched/types.h> |
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#include "ptp_private.h" |
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#define PTP_MAX_ALARMS 4 |
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#define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT) |
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#define PTP_PPS_EVENT PPS_CAPTUREASSERT |
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#define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC) |
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/* private globals */ |
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static dev_t ptp_devt; |
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static struct class *ptp_class; |
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static DEFINE_IDA(ptp_clocks_map); |
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/* time stamp event queue operations */ |
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static inline int queue_free(struct timestamp_event_queue *q) |
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{ |
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return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1; |
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} |
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static void enqueue_external_timestamp(struct timestamp_event_queue *queue, |
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struct ptp_clock_event *src) |
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{ |
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struct ptp_extts_event *dst; |
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unsigned long flags; |
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s64 seconds; |
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u32 remainder; |
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seconds = div_u64_rem(src->timestamp, 1000000000, &remainder); |
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spin_lock_irqsave(&queue->lock, flags); |
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dst = &queue->buf[queue->tail]; |
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dst->index = src->index; |
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dst->t.sec = seconds; |
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dst->t.nsec = remainder; |
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if (!queue_free(queue)) |
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queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS; |
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queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS; |
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spin_unlock_irqrestore(&queue->lock, flags); |
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} |
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s32 scaled_ppm_to_ppb(long ppm) |
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{ |
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/* |
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* The 'freq' field in the 'struct timex' is in parts per |
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* million, but with a 16 bit binary fractional field. |
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* |
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* We want to calculate |
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* |
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* ppb = scaled_ppm * 1000 / 2^16 |
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* |
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* which simplifies to |
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* |
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* ppb = scaled_ppm * 125 / 2^13 |
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*/ |
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s64 ppb = 1 + ppm; |
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ppb *= 125; |
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ppb >>= 13; |
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return (s32) ppb; |
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} |
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EXPORT_SYMBOL(scaled_ppm_to_ppb); |
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/* posix clock implementation */ |
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static int ptp_clock_getres(struct posix_clock *pc, struct timespec64 *tp) |
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{ |
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tp->tv_sec = 0; |
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tp->tv_nsec = 1; |
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return 0; |
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} |
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static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp) |
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{ |
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struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); |
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return ptp->info->settime64(ptp->info, tp); |
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} |
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static int ptp_clock_gettime(struct posix_clock *pc, struct timespec64 *tp) |
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{ |
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struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); |
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int err; |
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if (ptp->info->gettimex64) |
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err = ptp->info->gettimex64(ptp->info, tp, NULL); |
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else |
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err = ptp->info->gettime64(ptp->info, tp); |
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return err; |
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} |
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static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx) |
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{ |
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struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); |
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struct ptp_clock_info *ops; |
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int err = -EOPNOTSUPP; |
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ops = ptp->info; |
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if (tx->modes & ADJ_SETOFFSET) { |
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struct timespec64 ts; |
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ktime_t kt; |
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s64 delta; |
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ts.tv_sec = tx->time.tv_sec; |
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ts.tv_nsec = tx->time.tv_usec; |
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if (!(tx->modes & ADJ_NANO)) |
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ts.tv_nsec *= 1000; |
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if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC) |
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return -EINVAL; |
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kt = timespec64_to_ktime(ts); |
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delta = ktime_to_ns(kt); |
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err = ops->adjtime(ops, delta); |
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} else if (tx->modes & ADJ_FREQUENCY) { |
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s32 ppb = scaled_ppm_to_ppb(tx->freq); |
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if (ppb > ops->max_adj || ppb < -ops->max_adj) |
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return -ERANGE; |
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if (ops->adjfine) |
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err = ops->adjfine(ops, tx->freq); |
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else |
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err = ops->adjfreq(ops, ppb); |
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ptp->dialed_frequency = tx->freq; |
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} else if (tx->modes & ADJ_OFFSET) { |
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if (ops->adjphase) { |
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s32 offset = tx->offset; |
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if (!(tx->modes & ADJ_NANO)) |
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offset *= NSEC_PER_USEC; |
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err = ops->adjphase(ops, offset); |
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} |
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} else if (tx->modes == 0) { |
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tx->freq = ptp->dialed_frequency; |
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err = 0; |
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} |
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return err; |
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} |
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static struct posix_clock_operations ptp_clock_ops = { |
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.owner = THIS_MODULE, |
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.clock_adjtime = ptp_clock_adjtime, |
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.clock_gettime = ptp_clock_gettime, |
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.clock_getres = ptp_clock_getres, |
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.clock_settime = ptp_clock_settime, |
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.ioctl = ptp_ioctl, |
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.open = ptp_open, |
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.poll = ptp_poll, |
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.read = ptp_read, |
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}; |
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static void ptp_clock_release(struct device *dev) |
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{ |
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struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev); |
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ptp_cleanup_pin_groups(ptp); |
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mutex_destroy(&ptp->tsevq_mux); |
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mutex_destroy(&ptp->pincfg_mux); |
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ida_simple_remove(&ptp_clocks_map, ptp->index); |
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kfree(ptp); |
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} |
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static void ptp_aux_kworker(struct kthread_work *work) |
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{ |
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struct ptp_clock *ptp = container_of(work, struct ptp_clock, |
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aux_work.work); |
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struct ptp_clock_info *info = ptp->info; |
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long delay; |
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delay = info->do_aux_work(info); |
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if (delay >= 0) |
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kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay); |
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} |
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/* public interface */ |
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struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, |
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struct device *parent) |
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{ |
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struct ptp_clock *ptp; |
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int err = 0, index, major = MAJOR(ptp_devt); |
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if (info->n_alarm > PTP_MAX_ALARMS) |
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return ERR_PTR(-EINVAL); |
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/* Initialize a clock structure. */ |
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err = -ENOMEM; |
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ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL); |
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if (ptp == NULL) |
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goto no_memory; |
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index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL); |
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if (index < 0) { |
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err = index; |
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goto no_slot; |
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} |
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ptp->clock.ops = ptp_clock_ops; |
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ptp->info = info; |
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ptp->devid = MKDEV(major, index); |
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ptp->index = index; |
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spin_lock_init(&ptp->tsevq.lock); |
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mutex_init(&ptp->tsevq_mux); |
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mutex_init(&ptp->pincfg_mux); |
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init_waitqueue_head(&ptp->tsev_wq); |
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if (ptp->info->do_aux_work) { |
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kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker); |
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ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index); |
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if (IS_ERR(ptp->kworker)) { |
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err = PTR_ERR(ptp->kworker); |
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pr_err("failed to create ptp aux_worker %d\n", err); |
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goto kworker_err; |
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} |
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} |
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err = ptp_populate_pin_groups(ptp); |
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if (err) |
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goto no_pin_groups; |
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/* Register a new PPS source. */ |
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if (info->pps) { |
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struct pps_source_info pps; |
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memset(&pps, 0, sizeof(pps)); |
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snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index); |
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pps.mode = PTP_PPS_MODE; |
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pps.owner = info->owner; |
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ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS); |
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if (IS_ERR(ptp->pps_source)) { |
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err = PTR_ERR(ptp->pps_source); |
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pr_err("failed to register pps source\n"); |
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goto no_pps; |
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} |
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} |
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/* Initialize a new device of our class in our clock structure. */ |
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device_initialize(&ptp->dev); |
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ptp->dev.devt = ptp->devid; |
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ptp->dev.class = ptp_class; |
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ptp->dev.parent = parent; |
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ptp->dev.groups = ptp->pin_attr_groups; |
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ptp->dev.release = ptp_clock_release; |
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dev_set_drvdata(&ptp->dev, ptp); |
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dev_set_name(&ptp->dev, "ptp%d", ptp->index); |
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/* Create a posix clock and link it to the device. */ |
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err = posix_clock_register(&ptp->clock, &ptp->dev); |
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if (err) { |
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pr_err("failed to create posix clock\n"); |
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goto no_clock; |
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} |
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return ptp; |
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no_clock: |
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if (ptp->pps_source) |
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pps_unregister_source(ptp->pps_source); |
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no_pps: |
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ptp_cleanup_pin_groups(ptp); |
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no_pin_groups: |
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if (ptp->kworker) |
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kthread_destroy_worker(ptp->kworker); |
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kworker_err: |
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mutex_destroy(&ptp->tsevq_mux); |
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mutex_destroy(&ptp->pincfg_mux); |
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ida_simple_remove(&ptp_clocks_map, index); |
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no_slot: |
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kfree(ptp); |
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no_memory: |
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return ERR_PTR(err); |
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} |
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EXPORT_SYMBOL(ptp_clock_register); |
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int ptp_clock_unregister(struct ptp_clock *ptp) |
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{ |
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ptp->defunct = 1; |
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wake_up_interruptible(&ptp->tsev_wq); |
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if (ptp->kworker) { |
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kthread_cancel_delayed_work_sync(&ptp->aux_work); |
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kthread_destroy_worker(ptp->kworker); |
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} |
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/* Release the clock's resources. */ |
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if (ptp->pps_source) |
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pps_unregister_source(ptp->pps_source); |
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posix_clock_unregister(&ptp->clock); |
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return 0; |
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} |
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EXPORT_SYMBOL(ptp_clock_unregister); |
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void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event) |
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{ |
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struct pps_event_time evt; |
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switch (event->type) { |
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case PTP_CLOCK_ALARM: |
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break; |
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case PTP_CLOCK_EXTTS: |
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enqueue_external_timestamp(&ptp->tsevq, event); |
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wake_up_interruptible(&ptp->tsev_wq); |
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break; |
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case PTP_CLOCK_PPS: |
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pps_get_ts(&evt); |
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pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL); |
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break; |
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case PTP_CLOCK_PPSUSR: |
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pps_event(ptp->pps_source, &event->pps_times, |
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PTP_PPS_EVENT, NULL); |
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break; |
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} |
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} |
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EXPORT_SYMBOL(ptp_clock_event); |
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int ptp_clock_index(struct ptp_clock *ptp) |
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{ |
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return ptp->index; |
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} |
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EXPORT_SYMBOL(ptp_clock_index); |
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int ptp_find_pin(struct ptp_clock *ptp, |
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enum ptp_pin_function func, unsigned int chan) |
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{ |
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struct ptp_pin_desc *pin = NULL; |
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int i; |
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for (i = 0; i < ptp->info->n_pins; i++) { |
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if (ptp->info->pin_config[i].func == func && |
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ptp->info->pin_config[i].chan == chan) { |
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pin = &ptp->info->pin_config[i]; |
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break; |
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} |
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} |
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return pin ? i : -1; |
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} |
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EXPORT_SYMBOL(ptp_find_pin); |
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int ptp_find_pin_unlocked(struct ptp_clock *ptp, |
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enum ptp_pin_function func, unsigned int chan) |
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{ |
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int result; |
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mutex_lock(&ptp->pincfg_mux); |
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result = ptp_find_pin(ptp, func, chan); |
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mutex_unlock(&ptp->pincfg_mux); |
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return result; |
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} |
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EXPORT_SYMBOL(ptp_find_pin_unlocked); |
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int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay) |
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{ |
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return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay); |
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} |
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EXPORT_SYMBOL(ptp_schedule_worker); |
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void ptp_cancel_worker_sync(struct ptp_clock *ptp) |
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{ |
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kthread_cancel_delayed_work_sync(&ptp->aux_work); |
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} |
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EXPORT_SYMBOL(ptp_cancel_worker_sync); |
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/* module operations */ |
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static void __exit ptp_exit(void) |
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{ |
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class_destroy(ptp_class); |
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unregister_chrdev_region(ptp_devt, MINORMASK + 1); |
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ida_destroy(&ptp_clocks_map); |
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} |
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static int __init ptp_init(void) |
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{ |
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int err; |
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ptp_class = class_create(THIS_MODULE, "ptp"); |
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if (IS_ERR(ptp_class)) { |
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pr_err("ptp: failed to allocate class\n"); |
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return PTR_ERR(ptp_class); |
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} |
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err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp"); |
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if (err < 0) { |
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pr_err("ptp: failed to allocate device region\n"); |
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goto no_region; |
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} |
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ptp_class->dev_groups = ptp_groups; |
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pr_info("PTP clock support registered\n"); |
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return 0; |
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no_region: |
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class_destroy(ptp_class); |
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return err; |
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} |
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subsys_initcall(ptp_init); |
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module_exit(ptp_exit); |
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MODULE_AUTHOR("Richard Cochran <[email protected]>"); |
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MODULE_DESCRIPTION("PTP clocks support"); |
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MODULE_LICENSE("GPL");
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