ptp: Added a brand new class driver for ptp clocks.
This patch adds an infrastructure for hardware clocks that implement
IEEE 1588, the Precision Time Protocol (PTP). A class driver offers a
registration method to particular hardware clock drivers. Each clock is
presented as a standard POSIX clock.
The ancillary clock features are exposed in two different ways, via
the sysfs and by a character device.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John Stultz <john.stultz@linaro.org>
diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c
new file mode 100644
index 0000000..2f93926
--- /dev/null
+++ b/drivers/ptp/ptp_sysfs.c
@@ -0,0 +1,230 @@
+/*
+ * PTP 1588 clock support - sysfs interface.
+ *
+ * Copyright (C) 2010 OMICRON electronics GmbH
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/capability.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 snprintf(page, PAGE_SIZE-1, "%s\n", ptp->info->name);
+}
+
+#define PTP_SHOW_INT(name) \
+static ssize_t name##_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->name); \
+}
+
+PTP_SHOW_INT(max_adj);
+PTP_SHOW_INT(n_alarm);
+PTP_SHOW_INT(n_ext_ts);
+PTP_SHOW_INT(n_per_out);
+PTP_SHOW_INT(pps);
+
+#define PTP_RO_ATTR(_var, _name) { \
+ .attr = { .name = __stringify(_name), .mode = 0444 }, \
+ .show = _var##_show, \
+}
+
+struct device_attribute ptp_dev_attrs[] = {
+ PTP_RO_ATTR(clock_name, clock_name),
+ PTP_RO_ATTR(max_adj, max_adjustment),
+ PTP_RO_ATTR(n_alarm, n_alarms),
+ PTP_RO_ATTR(n_ext_ts, n_external_timestamps),
+ PTP_RO_ATTR(n_per_out, n_periodic_outputs),
+ PTP_RO_ATTR(pps, pps_available),
+ __ATTR_NULL,
+};
+
+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 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 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 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(extts_enable, 0220, NULL, extts_enable_store);
+static DEVICE_ATTR(fifo, 0444, extts_fifo_show, NULL);
+static DEVICE_ATTR(period, 0220, NULL, period_store);
+static DEVICE_ATTR(pps_enable, 0220, NULL, pps_enable_store);
+
+int ptp_cleanup_sysfs(struct ptp_clock *ptp)
+{
+ struct device *dev = ptp->dev;
+ struct ptp_clock_info *info = ptp->info;
+
+ if (info->n_ext_ts) {
+ device_remove_file(dev, &dev_attr_extts_enable);
+ device_remove_file(dev, &dev_attr_fifo);
+ }
+ if (info->n_per_out)
+ device_remove_file(dev, &dev_attr_period);
+
+ if (info->pps)
+ device_remove_file(dev, &dev_attr_pps_enable);
+
+ return 0;
+}
+
+int ptp_populate_sysfs(struct ptp_clock *ptp)
+{
+ struct device *dev = ptp->dev;
+ struct ptp_clock_info *info = ptp->info;
+ int err;
+
+ if (info->n_ext_ts) {
+ err = device_create_file(dev, &dev_attr_extts_enable);
+ if (err)
+ goto out1;
+ err = device_create_file(dev, &dev_attr_fifo);
+ if (err)
+ goto out2;
+ }
+ if (info->n_per_out) {
+ err = device_create_file(dev, &dev_attr_period);
+ if (err)
+ goto out3;
+ }
+ if (info->pps) {
+ err = device_create_file(dev, &dev_attr_pps_enable);
+ if (err)
+ goto out4;
+ }
+ return 0;
+out4:
+ if (info->n_per_out)
+ device_remove_file(dev, &dev_attr_period);
+out3:
+ if (info->n_ext_ts)
+ device_remove_file(dev, &dev_attr_fifo);
+out2:
+ if (info->n_ext_ts)
+ device_remove_file(dev, &dev_attr_extts_enable);
+out1:
+ return err;
+}