diff options
Diffstat (limited to 'drivers/ptp/ptp_vclock.c')
| -rw-r--r-- | drivers/ptp/ptp_vclock.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/ptp/ptp_vclock.c b/drivers/ptp/ptp_vclock.c new file mode 100644 index 000000000000..e0f87c57749a --- /dev/null +++ b/drivers/ptp/ptp_vclock.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * PTP virtual clock driver + * + * Copyright 2021 NXP + */ +#include <linux/slab.h> +#include "ptp_private.h" + +#define PTP_VCLOCK_CC_SHIFT 31 +#define PTP_VCLOCK_CC_MULT (1 << PTP_VCLOCK_CC_SHIFT) +#define PTP_VCLOCK_FADJ_SHIFT 9 +#define PTP_VCLOCK_FADJ_DENOMINATOR 15625ULL +#define PTP_VCLOCK_REFRESH_INTERVAL (HZ * 2) + +static int ptp_vclock_adjfine(struct ptp_clock_info *ptp, long scaled_ppm) +{ + struct ptp_vclock *vclock = info_to_vclock(ptp); + unsigned long flags; + s64 adj; + + adj = (s64)scaled_ppm << PTP_VCLOCK_FADJ_SHIFT; + adj = div_s64(adj, PTP_VCLOCK_FADJ_DENOMINATOR); + + spin_lock_irqsave(&vclock->lock, flags); + timecounter_read(&vclock->tc); + vclock->cc.mult = PTP_VCLOCK_CC_MULT + adj; + spin_unlock_irqrestore(&vclock->lock, flags); + + return 0; +} + +static int ptp_vclock_adjtime(struct ptp_clock_info *ptp, s64 delta) +{ + struct ptp_vclock *vclock = info_to_vclock(ptp); + unsigned long flags; + + spin_lock_irqsave(&vclock->lock, flags); + timecounter_adjtime(&vclock->tc, delta); + spin_unlock_irqrestore(&vclock->lock, flags); + + return 0; +} + +static int ptp_vclock_gettime(struct ptp_clock_info *ptp, + struct timespec64 *ts) +{ + struct ptp_vclock *vclock = info_to_vclock(ptp); + unsigned long flags; + u64 ns; + + spin_lock_irqsave(&vclock->lock, flags); + ns = timecounter_read(&vclock->tc); + spin_unlock_irqrestore(&vclock->lock, flags); + *ts = ns_to_timespec64(ns); + + return 0; +} + +static int ptp_vclock_settime(struct ptp_clock_info *ptp, + const struct timespec64 *ts) +{ + struct ptp_vclock *vclock = info_to_vclock(ptp); + u64 ns = timespec64_to_ns(ts); + unsigned long flags; + + spin_lock_irqsave(&vclock->lock, flags); + timecounter_init(&vclock->tc, &vclock->cc, ns); + spin_unlock_irqrestore(&vclock->lock, flags); + + return 0; +} + +static long ptp_vclock_refresh(struct ptp_clock_info *ptp) +{ + struct ptp_vclock *vclock = info_to_vclock(ptp); + struct timespec64 ts; + + ptp_vclock_gettime(&vclock->info, &ts); + + return PTP_VCLOCK_REFRESH_INTERVAL; +} + +static const struct ptp_clock_info ptp_vclock_info = { + .owner = THIS_MODULE, + .name = "ptp virtual clock", + /* The maximum ppb value that long scaled_ppm can support */ + .max_adj = 32767999, + .adjfine = ptp_vclock_adjfine, + .adjtime = ptp_vclock_adjtime, + .gettime64 = ptp_vclock_gettime, + .settime64 = ptp_vclock_settime, + .do_aux_work = ptp_vclock_refresh, +}; + +static u64 ptp_vclock_read(const struct cyclecounter *cc) +{ + struct ptp_vclock *vclock = cc_to_vclock(cc); + struct ptp_clock *ptp = vclock->pclock; + struct timespec64 ts = {}; + + if (ptp->info->gettimex64) + ptp->info->gettimex64(ptp->info, &ts, NULL); + else + ptp->info->gettime64(ptp->info, &ts); + + return timespec64_to_ns(&ts); +} + +static const struct cyclecounter ptp_vclock_cc = { + .read = ptp_vclock_read, + .mask = CYCLECOUNTER_MASK(32), + .mult = PTP_VCLOCK_CC_MULT, + .shift = PTP_VCLOCK_CC_SHIFT, +}; + +struct ptp_vclock *ptp_vclock_register(struct ptp_clock *pclock) +{ + struct ptp_vclock *vclock; + + vclock = kzalloc(sizeof(*vclock), GFP_KERNEL); + if (!vclock) + return NULL; + + vclock->pclock = pclock; + vclock->info = ptp_vclock_info; + vclock->cc = ptp_vclock_cc; + + snprintf(vclock->info.name, PTP_CLOCK_NAME_LEN, "ptp%d_virt", + pclock->index); + + spin_lock_init(&vclock->lock); + + vclock->clock = ptp_clock_register(&vclock->info, &pclock->dev); + if (IS_ERR_OR_NULL(vclock->clock)) { + kfree(vclock); + return NULL; + } + + timecounter_init(&vclock->tc, &vclock->cc, 0); + ptp_schedule_worker(vclock->clock, PTP_VCLOCK_REFRESH_INTERVAL); + + return vclock; +} + +void ptp_vclock_unregister(struct ptp_vclock *vclock) +{ + ptp_clock_unregister(vclock->clock); + kfree(vclock); +} + +int ptp_get_vclocks_index(int pclock_index, int **vclock_index) +{ + char name[PTP_CLOCK_NAME_LEN] = ""; + struct ptp_clock *ptp; + struct device *dev; + int num = 0; + + if (pclock_index < 0) + return num; + + snprintf(name, PTP_CLOCK_NAME_LEN, "ptp%d", pclock_index); + dev = class_find_device_by_name(ptp_class, name); + if (!dev) + return num; + + ptp = dev_get_drvdata(dev); + + if (mutex_lock_interruptible(&ptp->n_vclocks_mux)) { + put_device(dev); + return num; + } + + *vclock_index = kzalloc(sizeof(int) * ptp->n_vclocks, GFP_KERNEL); + if (!(*vclock_index)) + goto out; + + memcpy(*vclock_index, ptp->vclock_index, sizeof(int) * ptp->n_vclocks); + num = ptp->n_vclocks; +out: + mutex_unlock(&ptp->n_vclocks_mux); + put_device(dev); + return num; +} +EXPORT_SYMBOL(ptp_get_vclocks_index); + +void ptp_convert_timestamp(struct skb_shared_hwtstamps *hwtstamps, + int vclock_index) +{ + char name[PTP_CLOCK_NAME_LEN] = ""; + struct ptp_vclock *vclock; + struct ptp_clock *ptp; + unsigned long flags; + struct device *dev; + u64 ns; + + snprintf(name, PTP_CLOCK_NAME_LEN, "ptp%d", vclock_index); + dev = class_find_device_by_name(ptp_class, name); + if (!dev) + return; + + ptp = dev_get_drvdata(dev); + if (!ptp->is_virtual_clock) { + put_device(dev); + return; + } + + vclock = info_to_vclock(ptp->info); + + ns = ktime_to_ns(hwtstamps->hwtstamp); + + spin_lock_irqsave(&vclock->lock, flags); + ns = timecounter_cyc2time(&vclock->tc, ns); + spin_unlock_irqrestore(&vclock->lock, flags); + + put_device(dev); + hwtstamps->hwtstamp = ns_to_ktime(ns); +} +EXPORT_SYMBOL(ptp_convert_timestamp); |