linux/drivers/ptp/ptp_clock.c
Thomas Gleixner 74ba9207e1 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 441 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520071858.739733335@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 17:36:45 +02:00

413 lines
9.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PTP 1588 clock support
*
* Copyright (C) 2010 OMICRON electronics GmbH
*/
#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 <uapi/linux/sched/types.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 timespec64 *tp)
{
tp->tv_sec = 0;
tp->tv_nsec = 1;
return 0;
}
static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp)
{
struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
return ptp->info->settime64(ptp->info, tp);
}
static int ptp_clock_gettime(struct posix_clock *pc, struct timespec64 *tp)
{
struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
int err;
if (ptp->info->gettimex64)
err = ptp->info->gettimex64(ptp->info, tp, NULL);
else
err = ptp->info->gettime64(ptp->info, tp);
return err;
}
static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_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 timespec64 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 = timespec64_to_ktime(ts);
delta = ktime_to_ns(kt);
err = ops->adjtime(ops, delta);
} else if (tx->modes & ADJ_FREQUENCY) {
s32 ppb = scaled_ppm_to_ppb(tx->freq);
if (ppb > ops->max_adj || ppb < -ops->max_adj)
return -ERANGE;
if (ops->adjfine)
err = ops->adjfine(ops, tx->freq);
else
err = ops->adjfreq(ops, ppb);
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);
mutex_destroy(&ptp->pincfg_mux);
ida_simple_remove(&ptp_clocks_map, ptp->index);
kfree(ptp);
}
static void ptp_aux_kworker(struct kthread_work *work)
{
struct ptp_clock *ptp = container_of(work, struct ptp_clock,
aux_work.work);
struct ptp_clock_info *info = ptp->info;
long delay;
delay = info->do_aux_work(info);
if (delay >= 0)
kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay);
}
/* 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);
mutex_init(&ptp->pincfg_mux);
init_waitqueue_head(&ptp->tsev_wq);
if (ptp->info->do_aux_work) {
kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker);
ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index);
if (IS_ERR(ptp->kworker)) {
err = PTR_ERR(ptp->kworker);
pr_err("failed to create ptp aux_worker %d\n", err);
goto kworker_err;
}
}
err = ptp_populate_pin_groups(ptp);
if (err)
goto no_pin_groups;
/* Create a new device in our class. */
ptp->dev = device_create_with_groups(ptp_class, parent, ptp->devid,
ptp, ptp->pin_attr_groups,
"ptp%d", ptp->index);
if (IS_ERR(ptp->dev)) {
err = PTR_ERR(ptp->dev);
goto no_device;
}
/* 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 (IS_ERR(ptp->pps_source)) {
err = PTR_ERR(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:
device_destroy(ptp_class, ptp->devid);
no_device:
ptp_cleanup_pin_groups(ptp);
no_pin_groups:
if (ptp->kworker)
kthread_destroy_worker(ptp->kworker);
kworker_err:
mutex_destroy(&ptp->tsevq_mux);
mutex_destroy(&ptp->pincfg_mux);
ida_simple_remove(&ptp_clocks_map, index);
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);
if (ptp->kworker) {
kthread_cancel_delayed_work_sync(&ptp->aux_work);
kthread_destroy_worker(ptp->kworker);
}
/* Release the clock's resources. */
if (ptp->pps_source)
pps_unregister_source(ptp->pps_source);
device_destroy(ptp_class, ptp->devid);
ptp_cleanup_pin_groups(ptp);
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);
int ptp_find_pin(struct ptp_clock *ptp,
enum ptp_pin_function func, unsigned int chan)
{
struct ptp_pin_desc *pin = NULL;
int i;
mutex_lock(&ptp->pincfg_mux);
for (i = 0; i < ptp->info->n_pins; i++) {
if (ptp->info->pin_config[i].func == func &&
ptp->info->pin_config[i].chan == chan) {
pin = &ptp->info->pin_config[i];
break;
}
}
mutex_unlock(&ptp->pincfg_mux);
return pin ? i : -1;
}
EXPORT_SYMBOL(ptp_find_pin);
int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay)
{
return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay);
}
EXPORT_SYMBOL(ptp_schedule_worker);
/* 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_groups = ptp_groups;
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");