diff options
author | Richard Cochran <richardcochran@gmail.com> | 2011-04-22 12:03:08 +0200 |
---|---|---|
committer | John Stultz <john.stultz@linaro.org> | 2011-05-23 13:01:00 -0700 |
commit | d94ba80ebbea17f036cecb104398fbcd788aa742 (patch) | |
tree | 7fe40228c5ea2bb77f2892b722d27155df8c1157 /drivers/ptp/ptp_sysfs.c | |
parent | caebc160ce3f76761cc62ad96ef6d6f30f54e3dd (diff) | |
download | linux-d94ba80ebbea17f036cecb104398fbcd788aa742.tar.gz linux-d94ba80ebbea17f036cecb104398fbcd788aa742.tar.bz2 linux-d94ba80ebbea17f036cecb104398fbcd788aa742.zip |
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>
Diffstat (limited to 'drivers/ptp/ptp_sysfs.c')
-rw-r--r-- | drivers/ptp/ptp_sysfs.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c new file mode 100644 index 000000000000..2f93926ac976 --- /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; +} |