ssize_t ptp_read(struct posix_clock *pc,
uint rdflags, char __user *buf, size_t cnt)
{
struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
struct timestamp_event_queue *queue = &ptp->tsevq;
struct ptp_extts_event event[PTP_BUF_TIMESTAMPS];
unsigned long flags;
size_t qcnt, i;
if (cnt % sizeof(struct ptp_extts_event) != 0)
return -EINVAL;
if (cnt > sizeof(event))
cnt = sizeof(event);
cnt = cnt / sizeof(struct ptp_extts_event);
if (mutex_lock_interruptible(&ptp->tsevq_mux))
return -ERESTARTSYS;
if (wait_event_interruptible(ptp->tsev_wq, queue_cnt(queue))) {
mutex_unlock(&ptp->tsevq_mux);
return -ERESTARTSYS;
}
spin_lock_irqsave(&queue->lock, flags);
qcnt = queue_cnt(queue);
if (cnt > qcnt)
cnt = qcnt;
for (i = 0; i < cnt; i++) {
event[i] = queue->buf[queue->head];
queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
}
spin_unlock_irqrestore(&queue->lock, flags);
cnt = cnt * sizeof(struct ptp_extts_event);
mutex_unlock(&ptp->tsevq_mux);
if (copy_to_user(buf, event, cnt)) {
mutex_unlock(&ptp->tsevq_mux);
return -EFAULT;
}
return cnt;
}
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;
}
__poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
{
struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
poll_wait(fp, &ptp->tsev_wq, wait);
return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
}
ssize_t ptp_read(struct posix_clock *pc,
uint rdflags, char __user *buf, size_t cnt)
{
struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
struct timestamp_event_queue *queue = &ptp->tsevq;
struct ptp_extts_event *event;
unsigned long flags;
size_t qcnt, i;
int result;
if (cnt % sizeof(struct ptp_extts_event) != 0)
return -EINVAL;
if (cnt > EXTTS_BUFSIZE)
cnt = EXTTS_BUFSIZE;
cnt = cnt / sizeof(struct ptp_extts_event);
if (mutex_lock_interruptible(&ptp->tsevq_mux))
return -ERESTARTSYS;
if (wait_event_interruptible(ptp->tsev_wq,
ptp->defunct || queue_cnt(queue))) {
mutex_unlock(&ptp->tsevq_mux);
return -ERESTARTSYS;
}
if (ptp->defunct) {
mutex_unlock(&ptp->tsevq_mux);
return -ENODEV;
}
event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
if (!event) {
mutex_unlock(&ptp->tsevq_mux);
return -ENOMEM;
}
spin_lock_irqsave(&queue->lock, flags);
qcnt = queue_cnt(queue);
if (cnt > qcnt)
cnt = qcnt;
for (i = 0; i < cnt; i++) {
event[i] = queue->buf[queue->head];
queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
}
spin_unlock_irqrestore(&queue->lock, flags);
cnt = cnt * sizeof(struct ptp_extts_event);
mutex_unlock(&ptp->tsevq_mux);
result = cnt;
if (copy_to_user(buf, event, cnt))
result = -EFAULT;
kfree(event);
return result;
}
static inline int queue_free(struct timestamp_event_queue *q)
{
return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
}
