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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/ptp/ptp_clock.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/ptp/ptp_clock.c')
-rw-r--r-- | drivers/ptp/ptp_clock.c | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c new file mode 100644 index 000000000..ed766943a --- /dev/null +++ b/drivers/ptp/ptp_clock.c @@ -0,0 +1,439 @@ +// 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; + + /* Both WRITE_ONCE() are paired with READ_ONCE() in queue_cnt() */ + if (!queue_free(queue)) + WRITE_ONCE(queue->head, (queue->head + 1) % PTP_MAX_TIMESTAMPS); + + WRITE_ONCE(queue->tail, (queue->tail + 1) % PTP_MAX_TIMESTAMPS); + + spin_unlock_irqrestore(&queue->lock, flags); +} + +long 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 (long) ppb; +} +EXPORT_SYMBOL(scaled_ppm_to_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) { + long 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 & ADJ_OFFSET) { + if (ops->adjphase) { + s32 offset = tx->offset; + + if (!(tx->modes & ADJ_NANO)) + offset *= NSEC_PER_USEC; + + err = ops->adjphase(ops, offset); + } + } 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 ptp_clock_release(struct device *dev) +{ + struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev); + + ptp_cleanup_pin_groups(ptp); + 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->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; + + /* 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; + } + } + + /* Initialize a new device of our class in our clock structure. */ + device_initialize(&ptp->dev); + ptp->dev.devt = ptp->devid; + ptp->dev.class = ptp_class; + ptp->dev.parent = parent; + ptp->dev.groups = ptp->pin_attr_groups; + ptp->dev.release = ptp_clock_release; + dev_set_drvdata(&ptp->dev, ptp); + dev_set_name(&ptp->dev, "ptp%d", ptp->index); + + /* Create a posix clock and link it to the device. */ + err = posix_clock_register(&ptp->clock, &ptp->dev); + 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_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); + + 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; + + 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; + } + } + + return pin ? i : -1; +} +EXPORT_SYMBOL(ptp_find_pin); + +int ptp_find_pin_unlocked(struct ptp_clock *ptp, + enum ptp_pin_function func, unsigned int chan) +{ + int result; + + mutex_lock(&ptp->pincfg_mux); + + result = ptp_find_pin(ptp, func, chan); + + mutex_unlock(&ptp->pincfg_mux); + + return result; +} +EXPORT_SYMBOL(ptp_find_pin_unlocked); + +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); + +void ptp_cancel_worker_sync(struct ptp_clock *ptp) +{ + kthread_cancel_delayed_work_sync(&ptp->aux_work); +} +EXPORT_SYMBOL(ptp_cancel_worker_sync); + +/* 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"); |