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42704b26b0
linux/drivers/ptp/ptp_sysfs.c
Gerhard Engleder 42704b26b0 ptp: Add cycles support for virtual clocks 
ptp vclocks require a free running time for their timecounter.
Currently only a physical clock forced to free running is supported.
If vclocks are used, then the physical clock cannot be synchronized
anymore. The synchronized time is not available in hardware in this
case. As a result, timed transmission with TAPRIO hardware support
is not possible anymore.

If hardware would support a free running time additionally to the
physical clock, then the physical clock does not need to be forced to
free running. Thus, the physical clocks can still be synchronized
while vclocks are in use.

The physical clock could be used to synchronize the time domain of the
TSN network and trigger TAPRIO. In parallel vclocks can be used to
synchronize other time domains.

Introduce support for a free running cycle counter called cycles to
physical clocks. Rework ptp vclocks to use this free running cycle
counter. Default implementation is based on time of physical clock.
Thus, behavior of ptp vclocks based on physical clocks without free
running cycle counter is identical to previous behavior.

Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-05-10 09:48:08 +02:00

466 lines
11 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PTP 1588 clock support - sysfs interface.
*
* Copyright (C) 2010 OMICRON electronics GmbH
* Copyright 2021 NXP
*/
#include <linux/capability.h>
#include <linux/slab.h>
#include "ptp_private.h"
static ssize_t clock_name_show(struct device *dev,
struct device_attribute *attr, char *page)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
return sysfs_emit(page, "%s\n", ptp->info->name);
}
static DEVICE_ATTR_RO(clock_name);
#define PTP_SHOW_INT(name, var) \
static ssize_t var##_show(struct device *dev, \
struct device_attribute *attr, char *page) \
{ \
struct ptp_clock *ptp = dev_get_drvdata(dev); \
return snprintf(page, PAGE_SIZE-1, "%d\n", ptp->info->var); \
} \
static DEVICE_ATTR(name, 0444, var##_show, NULL);
PTP_SHOW_INT(max_adjustment, max_adj);
PTP_SHOW_INT(n_alarms, n_alarm);
PTP_SHOW_INT(n_external_timestamps, n_ext_ts);
PTP_SHOW_INT(n_periodic_outputs, n_per_out);
PTP_SHOW_INT(n_programmable_pins, n_pins);
PTP_SHOW_INT(pps_available, pps);
static ssize_t extts_enable_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
struct ptp_clock_info *ops = ptp->info;
struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
int cnt, enable;
int err = -EINVAL;
cnt = sscanf(buf, "%u %d", &req.extts.index, &enable);
if (cnt != 2)
goto out;
if (req.extts.index >= ops->n_ext_ts)
goto out;
err = ops->enable(ops, &req, enable ? 1 : 0);
if (err)
goto out;
return count;
out:
return err;
}
static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
static ssize_t extts_fifo_show(struct device *dev,
struct device_attribute *attr, char *page)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
struct timestamp_event_queue *queue = &ptp->tsevq;
struct ptp_extts_event event;
unsigned long flags;
size_t qcnt;
int cnt = 0;
memset(&event, 0, sizeof(event));
if (mutex_lock_interruptible(&ptp->tsevq_mux))
return -ERESTARTSYS;
spin_lock_irqsave(&queue->lock, flags);
qcnt = queue_cnt(queue);
if (qcnt) {
event = queue->buf[queue->head];
queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
}
spin_unlock_irqrestore(&queue->lock, flags);
if (!qcnt)
goto out;
cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
event.index, event.t.sec, event.t.nsec);
out:
mutex_unlock(&ptp->tsevq_mux);
return cnt;
}
static DEVICE_ATTR(fifo, 0444, extts_fifo_show, NULL);
static ssize_t period_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
struct ptp_clock_info *ops = ptp->info;
struct ptp_clock_request req = { .type = PTP_CLK_REQ_PEROUT };
int cnt, enable, err = -EINVAL;
cnt = sscanf(buf, "%u %lld %u %lld %u", &req.perout.index,
&req.perout.start.sec, &req.perout.start.nsec,
&req.perout.period.sec, &req.perout.period.nsec);
if (cnt != 5)
goto out;
if (req.perout.index >= ops->n_per_out)
goto out;
enable = req.perout.period.sec || req.perout.period.nsec;
err = ops->enable(ops, &req, enable);
if (err)
goto out;
return count;
out:
return err;
}
static DEVICE_ATTR(period, 0220, NULL, period_store);
static ssize_t pps_enable_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
struct ptp_clock_info *ops = ptp->info;
struct ptp_clock_request req = { .type = PTP_CLK_REQ_PPS };
int cnt, enable;
int err = -EINVAL;
if (!capable(CAP_SYS_TIME))
return -EPERM;
cnt = sscanf(buf, "%d", &enable);
if (cnt != 1)
goto out;
err = ops->enable(ops, &req, enable ? 1 : 0);
if (err)
goto out;
return count;
out:
return err;
}
static DEVICE_ATTR(pps_enable, 0220, NULL, pps_enable_store);
static int unregister_vclock(struct device *dev, void *data)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
struct ptp_clock_info *info = ptp->info;
struct ptp_vclock *vclock;
u32 *num = data;
vclock = info_to_vclock(info);
dev_info(dev->parent, "delete virtual clock ptp%d\n",
vclock->clock->index);
ptp_vclock_unregister(vclock);
(*num)--;
/* For break. Not error. */
if (*num == 0)
return -EINVAL;
return 0;
}
static ssize_t n_vclocks_show(struct device *dev,
struct device_attribute *attr, char *page)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
ssize_t size;
if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
return -ERESTARTSYS;
size = snprintf(page, PAGE_SIZE - 1, "%u\n", ptp->n_vclocks);
mutex_unlock(&ptp->n_vclocks_mux);
return size;
}
static ssize_t n_vclocks_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
struct ptp_vclock *vclock;
int err = -EINVAL;
u32 num, i;
if (kstrtou32(buf, 0, &num))
return err;
if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
return -ERESTARTSYS;
if (num > ptp->max_vclocks) {
dev_err(dev, "max value is %d\n", ptp->max_vclocks);
goto out;
}
/* Need to create more vclocks */
if (num > ptp->n_vclocks) {
for (i = 0; i < num - ptp->n_vclocks; i++) {
vclock = ptp_vclock_register(ptp);
if (!vclock)
goto out;
*(ptp->vclock_index + ptp->n_vclocks + i) =
vclock->clock->index;
dev_info(dev, "new virtual clock ptp%d\n",
vclock->clock->index);
}
}
/* Need to delete vclocks */
if (num < ptp->n_vclocks) {
i = ptp->n_vclocks - num;
device_for_each_child_reverse(dev, &i,
unregister_vclock);
for (i = 1; i <= ptp->n_vclocks - num; i++)
*(ptp->vclock_index + ptp->n_vclocks - i) = -1;
}
/* Need to inform about changed physical clock behavior */
if (!ptp->has_cycles) {
if (num == 0)
dev_info(dev, "only physical clock in use now\n");
else
dev_info(dev, "guarantee physical clock free running\n");
}
ptp->n_vclocks = num;
mutex_unlock(&ptp->n_vclocks_mux);
return count;
out:
mutex_unlock(&ptp->n_vclocks_mux);
return err;
}
static DEVICE_ATTR_RW(n_vclocks);
static ssize_t max_vclocks_show(struct device *dev,
struct device_attribute *attr, char *page)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
ssize_t size;
size = snprintf(page, PAGE_SIZE - 1, "%u\n", ptp->max_vclocks);
return size;
}
static ssize_t max_vclocks_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
unsigned int *vclock_index;
int err = -EINVAL;
size_t size;
u32 max;
if (kstrtou32(buf, 0, &max) || max == 0)
return -EINVAL;
if (max == ptp->max_vclocks)
return count;
if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
return -ERESTARTSYS;
if (max < ptp->n_vclocks)
goto out;
size = sizeof(int) * max;
vclock_index = kzalloc(size, GFP_KERNEL);
if (!vclock_index) {
err = -ENOMEM;
goto out;
}
size = sizeof(int) * ptp->n_vclocks;
memcpy(vclock_index, ptp->vclock_index, size);
kfree(ptp->vclock_index);
ptp->vclock_index = vclock_index;
ptp->max_vclocks = max;
mutex_unlock(&ptp->n_vclocks_mux);
return count;
out:
mutex_unlock(&ptp->n_vclocks_mux);
return err;
}
static DEVICE_ATTR_RW(max_vclocks);
static struct attribute *ptp_attrs[] = {
&dev_attr_clock_name.attr,
&dev_attr_max_adjustment.attr,
&dev_attr_n_alarms.attr,
&dev_attr_n_external_timestamps.attr,
&dev_attr_n_periodic_outputs.attr,
&dev_attr_n_programmable_pins.attr,
&dev_attr_pps_available.attr,
&dev_attr_extts_enable.attr,
&dev_attr_fifo.attr,
&dev_attr_period.attr,
&dev_attr_pps_enable.attr,
&dev_attr_n_vclocks.attr,
&dev_attr_max_vclocks.attr,
NULL
};
static umode_t ptp_is_attribute_visible(struct kobject *kobj,
struct attribute *attr, int n)
{
struct device *dev = kobj_to_dev(kobj);
struct ptp_clock *ptp = dev_get_drvdata(dev);
struct ptp_clock_info *info = ptp->info;
umode_t mode = attr->mode;
if (attr == &dev_attr_extts_enable.attr ||
attr == &dev_attr_fifo.attr) {
if (!info->n_ext_ts)
mode = 0;
} else if (attr == &dev_attr_period.attr) {
if (!info->n_per_out)
mode = 0;
} else if (attr == &dev_attr_pps_enable.attr) {
if (!info->pps)
mode = 0;
} else if (attr == &dev_attr_n_vclocks.attr ||
attr == &dev_attr_max_vclocks.attr) {
if (ptp->is_virtual_clock)
mode = 0;
}
return mode;
}
static const struct attribute_group ptp_group = {
.is_visible = ptp_is_attribute_visible,
.attrs = ptp_attrs,
};
const struct attribute_group *ptp_groups[] = {
&ptp_group,
NULL
};
static int ptp_pin_name2index(struct ptp_clock *ptp, const char *name)
{
int i;
for (i = 0; i < ptp->info->n_pins; i++) {
if (!strcmp(ptp->info->pin_config[i].name, name))
return i;
}
return -1;
}
static ssize_t ptp_pin_show(struct device *dev, struct device_attribute *attr,
char *page)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
unsigned int func, chan;
int index;
index = ptp_pin_name2index(ptp, attr->attr.name);
if (index < 0)
return -EINVAL;
if (mutex_lock_interruptible(&ptp->pincfg_mux))
return -ERESTARTSYS;
func = ptp->info->pin_config[index].func;
chan = ptp->info->pin_config[index].chan;
mutex_unlock(&ptp->pincfg_mux);
return sysfs_emit(page, "%u %u\n", func, chan);
}
static ssize_t ptp_pin_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
unsigned int func, chan;
int cnt, err, index;
cnt = sscanf(buf, "%u %u", &func, &chan);
if (cnt != 2)
return -EINVAL;
index = ptp_pin_name2index(ptp, attr->attr.name);
if (index < 0)
return -EINVAL;
if (mutex_lock_interruptible(&ptp->pincfg_mux))
return -ERESTARTSYS;
err = ptp_set_pinfunc(ptp, index, func, chan);
mutex_unlock(&ptp->pincfg_mux);
if (err)
return err;
return count;
}
int ptp_populate_pin_groups(struct ptp_clock *ptp)
{
struct ptp_clock_info *info = ptp->info;
int err = -ENOMEM, i, n_pins = info->n_pins;
if (!n_pins)
return 0;
ptp->pin_dev_attr = kcalloc(n_pins, sizeof(*ptp->pin_dev_attr),
GFP_KERNEL);
if (!ptp->pin_dev_attr)
goto no_dev_attr;
ptp->pin_attr = kcalloc(1 + n_pins, sizeof(*ptp->pin_attr), GFP_KERNEL);
if (!ptp->pin_attr)
goto no_pin_attr;
for (i = 0; i < n_pins; i++) {
struct device_attribute *da = &ptp->pin_dev_attr[i];
sysfs_attr_init(&da->attr);
da->attr.name = info->pin_config[i].name;
da->attr.mode = 0644;
da->show = ptp_pin_show;
da->store = ptp_pin_store;
ptp->pin_attr[i] = &da->attr;
}
ptp->pin_attr_group.name = "pins";
ptp->pin_attr_group.attrs = ptp->pin_attr;
ptp->pin_attr_groups[0] = &ptp->pin_attr_group;
return 0;
no_pin_attr:
kfree(ptp->pin_dev_attr);
no_dev_attr:
return err;
}
void ptp_cleanup_pin_groups(struct ptp_clock *ptp)
{
kfree(ptp->pin_attr);
kfree(ptp->pin_dev_attr);
}
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