| // 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); |
| } |
| |
| 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; |
| } |
| 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) { |
| 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 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; |
| |
| 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"); |