Support ptp physical/virtual clocks conversion via sysfs.
There will be a new attribute n_vclocks under ptp physical
clock sysfs.
- In default, the value is 0 meaning only ptp physical clock
is in use.
- Setting the value can create corresponding number of ptp
virtual clocks to use. But current physical clock is guaranteed
to stay free running.
- Setting the value back to 0 can delete virtual clocks and back
use physical clock again.
Signed-off-by: Yangbo Lu <yangbo.lu@xxxxxxx>
---
Changes for v2:
- Split from v1 patch #2.
- Converted to num_vclocks for creating virtual clocks.
- Guranteed physical clock free running when using virtual
clocks.
- Fixed build warning.
- Updated copyright.
Changes for v3:
- Protected concurrency of ptp->num_vclocks accessing.
---
Documentation/ABI/testing/sysfs-ptp | 13 +++++
drivers/ptp/ptp_clock.c | 22 +++++++
drivers/ptp/ptp_private.h | 15 +++++
drivers/ptp/ptp_sysfs.c | 89 +++++++++++++++++++++++++++++
include/uapi/linux/ptp_clock.h | 5 ++
5 files changed, 144 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-ptp b/Documentation/ABI/testing/sysfs-ptp
index 2363ad810ddb..2ef11b775f47 100644
--- a/Documentation/ABI/testing/sysfs-ptp
+++ b/Documentation/ABI/testing/sysfs-ptp
@@ -61,6 +61,19 @@ Description:
This file contains the number of programmable pins
offered by the PTP hardware clock.
+What: /sys/class/ptp/ptpN/n_vclocks
+Date: May 2021
+Contact: Yangbo Lu <yangbo.lu@xxxxxxx>
+Description:
+ This file contains the ptp virtual clocks number in use,
+ based on current ptp physical clock. In default, the
+ value is 0 meaning only ptp physical clock is in use.
+ Setting the value can create corresponding number of ptp
+ virtual clocks to use. But current ptp physical clock is
+ guaranteed to stay free running. Setting the value back
+ to 0 can delete ptp virtual clocks and back use ptp
+ physical clock again.
+
What: /sys/class/ptp/ptpN/pins
Date: March 2014
Contact: Richard Cochran <richardcochran@xxxxxxxxx>
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index a780435331c8..78414b3e16dd 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -76,6 +76,11 @@ static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp
{
struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
+ if (ptp_guaranteed_pclock(ptp)) {
+ pr_err("ptp: virtual clock in use, guarantee physical clock free running\n");
+ return -EBUSY;
+ }
+
return ptp->info->settime64(ptp->info, tp);
}
@@ -97,6 +102,11 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx)
struct ptp_clock_info *ops;
int err = -EOPNOTSUPP;
+ if (ptp_guaranteed_pclock(ptp)) {
+ pr_err("ptp: virtual clock in use, guarantee physical clock free running\n");
+ return -EBUSY;
+ }
+
ops = ptp->info;
if (tx->modes & ADJ_SETOFFSET) {
@@ -161,6 +171,7 @@ static void ptp_clock_release(struct device *dev)
ptp_cleanup_pin_groups(ptp);
mutex_destroy(&ptp->tsevq_mux);
mutex_destroy(&ptp->pincfg_mux);
+ mutex_destroy(&ptp->n_vclocks_mux);
ida_simple_remove(&ptp_clocks_map, ptp->index);
kfree(ptp);
}
@@ -208,6 +219,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
spin_lock_init(&ptp->tsevq.lock);
mutex_init(&ptp->tsevq_mux);
mutex_init(&ptp->pincfg_mux);
+ mutex_init(&ptp->n_vclocks_mux);
init_waitqueue_head(&ptp->tsev_wq);
if (ptp->info->do_aux_work) {
@@ -220,6 +232,10 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
}
}
+ /* PTP virtual clock is being registered under physical clock */
+ if (parent->class && strcmp(parent->class->name, "ptp") == 0)
+ ptp->vclock_flag = true;
+
err = ptp_populate_pin_groups(ptp);
if (err)
goto no_pin_groups;
@@ -269,6 +285,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
kworker_err:
mutex_destroy(&ptp->tsevq_mux);
mutex_destroy(&ptp->pincfg_mux);
+ mutex_destroy(&ptp->n_vclocks_mux);
ida_simple_remove(&ptp_clocks_map, index);
no_slot:
kfree(ptp);
@@ -279,6 +296,11 @@ EXPORT_SYMBOL(ptp_clock_register);
int ptp_clock_unregister(struct ptp_clock *ptp)
{
+ if (ptp_guaranteed_pclock(ptp)) {
+ pr_err("ptp: virtual clock in use, guarantee physical clock free running\n");
+ return -EBUSY;
+ }
+
ptp->defunct = 1;
wake_up_interruptible(&ptp->tsev_wq);
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 3f388d63904c..6949afc9d733 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -46,6 +46,9 @@ struct ptp_clock {
const struct attribute_group *pin_attr_groups[2];
struct kthread_worker *kworker;
struct kthread_delayed_work aux_work;
+ u8 n_vclocks;
+ struct mutex n_vclocks_mux; /* protect concurrent n_vclocks access */
+ bool vclock_flag;
};
#define info_to_vclock(d) container_of((d), struct ptp_vclock, info)
@@ -75,6 +78,18 @@ static inline int queue_cnt(struct timestamp_event_queue *q)
return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt;
}
+/*
+ * Guarantee physical clock to stay free running, if ptp virtual clocks
+ * on it are in use.
+ */
+static inline bool ptp_guaranteed_pclock(struct ptp_clock *ptp)
+{
+ if (!ptp->vclock_flag && ptp->n_vclocks)
+ return true;
+
+ return false;
+}
+
/*
* see ptp_chardev.c
*/
diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c
index be076a91e20e..600edd7a90af 100644
--- a/drivers/ptp/ptp_sysfs.c
+++ b/drivers/ptp/ptp_sysfs.c
@@ -3,6 +3,7 @@
* PTP 1588 clock support - sysfs interface.
*
* Copyright (C) 2010 OMICRON electronics GmbH
+ * Copyright 2021 NXP
*/
#include <linux/capability.h>
#include <linux/slab.h>
@@ -148,6 +149,90 @@ static ssize_t pps_enable_store(struct device *dev,
}
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;
+ u8 *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);
+
+ return snprintf(page, PAGE_SIZE-1, "%d\n", ptp->n_vclocks);
+}
+
+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;
+ u8 num, i;
+
+ if (kstrtou8(buf, 0, &num))
+ goto out;
+
+ if (num > PTP_MAX_VCLOCKS) {
+ dev_err(dev, "max value is %d\n", PTP_MAX_VCLOCKS);
+ goto out;
+ }
+
+ if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
+ return -ERESTARTSYS;
+
+ /* 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) {
+ mutex_unlock(&ptp->n_vclocks_mux);
+ goto out;
+ }
+
+ 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);
+ }
+
+ 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:
+ return err;
+}
+static DEVICE_ATTR_RW(n_vclocks);
+
static struct attribute *ptp_attrs[] = {
&dev_attr_clock_name.attr,
@@ -162,6 +247,7 @@ static struct attribute *ptp_attrs[] = {
&dev_attr_fifo.attr,
&dev_attr_period.attr,
&dev_attr_pps_enable.attr,
+ &dev_attr_n_vclocks.attr,
NULL
};
@@ -183,6 +269,9 @@ static umode_t ptp_is_attribute_visible(struct kobject *kobj,
} else if (attr == &dev_attr_pps_enable.attr) {
if (!info->pps)
mode = 0;
+ } else if (attr == &dev_attr_n_vclocks.attr) {
+ if (ptp->vclock_flag)
+ mode = 0;
}
return mode;
diff --git a/include/uapi/linux/ptp_clock.h b/include/uapi/linux/ptp_clock.h
index 1d108d597f66..4b933dc1b81b 100644
--- a/include/uapi/linux/ptp_clock.h
+++ b/include/uapi/linux/ptp_clock.h
@@ -69,6 +69,11 @@
*/
#define PTP_PEROUT_V1_VALID_FLAGS (0)
+/*
+ * Max number of PTP virtual clocks per PTP physical clock
+ */
+#define PTP_MAX_VCLOCKS 20
+
/*
* struct ptp_clock_time - represents a time value
*
--
2.25.1
