drivers/ptp/ptp_sysfs.c

   1 /*
   2  * PTP 1588 clock support - sysfs interface.
   3  *
   4  * Copyright (C) 2010 OMICRON electronics GmbH
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20 #include <linux/capability.h>
  21
  22 #include "ptp_private.h"
  23
  24 static ssize_t clock_name_show(struct device *dev,
  25                                struct device_attribute *attr, char *page)
  26 {
  27         struct ptp_clock *ptp = dev_get_drvdata(dev);
  28         return snprintf(page, PAGE_SIZE-1, "%s\n", ptp->info->name);
  29 }
  30 static DEVICE_ATTR(clock_name, 0444, clock_name_show, NULL);
  31
  32 #define PTP_SHOW_INT(name, var)                                         \
  33 static ssize_t var##_show(struct device *dev,                           \
  34                            struct device_attribute *attr, char *page)   \
  35 {                                                                       \
  36         struct ptp_clock *ptp = dev_get_drvdata(dev);                   \
  37         return snprintf(page, PAGE_SIZE-1, "%d\n", ptp->info->var);     \
  38 }                                                                       \
  39 static DEVICE_ATTR(name, 0444, var##_show, NULL);
  40
  41 PTP_SHOW_INT(max_adjustment, max_adj);
  42 PTP_SHOW_INT(n_alarms, n_alarm);
  43 PTP_SHOW_INT(n_external_timestamps, n_ext_ts);
  44 PTP_SHOW_INT(n_periodic_outputs, n_per_out);
  45 PTP_SHOW_INT(pps_available, pps);
  46
  47 static struct attribute *ptp_attrs[] = {
  48         &dev_attr_clock_name.attr,
  49         &dev_attr_max_adjustment.attr,
  50         &dev_attr_n_alarms.attr,
  51         &dev_attr_n_external_timestamps.attr,
  52         &dev_attr_n_periodic_outputs.attr,
  53         &dev_attr_pps_available.attr,
  54         NULL,
  55 };
  56
  57 static const struct attribute_group ptp_group = {
  58         .attrs = ptp_attrs,
  59 };
  60
  61 const struct attribute_group *ptp_groups[] = {
  62         &ptp_group,
  63         NULL,
  64 };
  65
  66
  67 static ssize_t extts_enable_store(struct device *dev,
  68                                   struct device_attribute *attr,
  69                                   const char *buf, size_t count)
  70 {
  71         struct ptp_clock *ptp = dev_get_drvdata(dev);
  72         struct ptp_clock_info *ops = ptp->info;
  73         struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
  74         int cnt, enable;
  75         int err = -EINVAL;
  76
  77         cnt = sscanf(buf, "%u %d", &req.extts.index, &enable);
  78         if (cnt != 2)
  79                 goto out;
  80         if (req.extts.index >= ops->n_ext_ts)
  81                 goto out;
  82
  83         err = ops->enable(ops, &req, enable ? 1 : 0);
  84         if (err)
  85                 goto out;
  86
  87         return count;
  88 out:
  89         return err;
  90 }
  91
  92 static ssize_t extts_fifo_show(struct device *dev,
  93                                struct device_attribute *attr, char *page)
  94 {
  95         struct ptp_clock *ptp = dev_get_drvdata(dev);
  96         struct timestamp_event_queue *queue = &ptp->tsevq;
  97         struct ptp_extts_event event;
  98         unsigned long flags;
  99         size_t qcnt;
 100         int cnt = 0;
 101
 102         memset(&event, 0, sizeof(event));
 103
 104         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 105                 return -ERESTARTSYS;
 106
 107         spin_lock_irqsave(&queue->lock, flags);
 108         qcnt = queue_cnt(queue);
 109         if (qcnt) {
 110                 event = queue->buf[queue->head];
 111                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 112         }
 113         spin_unlock_irqrestore(&queue->lock, flags);
 114
 115         if (!qcnt)
 116                 goto out;
 117
 118         cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
 119                        event.index, event.t.sec, event.t.nsec);
 120 out:
 121         mutex_unlock(&ptp->tsevq_mux);
 122         return cnt;
 123 }
 124
 125 static ssize_t period_store(struct device *dev,
 126                             struct device_attribute *attr,
 127                             const char *buf, size_t count)
 128 {
 129         struct ptp_clock *ptp = dev_get_drvdata(dev);
 130         struct ptp_clock_info *ops = ptp->info;
 131         struct ptp_clock_request req = { .type = PTP_CLK_REQ_PEROUT };
 132         int cnt, enable, err = -EINVAL;
 133
 134         cnt = sscanf(buf, "%u %lld %u %lld %u", &req.perout.index,
 135                      &req.perout.start.sec, &req.perout.start.nsec,
 136                      &req.perout.period.sec, &req.perout.period.nsec);
 137         if (cnt != 5)
 138                 goto out;
 139         if (req.perout.index >= ops->n_per_out)
 140                 goto out;
 141
 142         enable = req.perout.period.sec || req.perout.period.nsec;
 143         err = ops->enable(ops, &req, enable);
 144         if (err)
 145                 goto out;
 146
 147         return count;
 148 out:
 149         return err;
 150 }
 151
 152 static ssize_t pps_enable_store(struct device *dev,
 153                                 struct device_attribute *attr,
 154                                 const char *buf, size_t count)
 155 {
 156         struct ptp_clock *ptp = dev_get_drvdata(dev);
 157         struct ptp_clock_info *ops = ptp->info;
 158         struct ptp_clock_request req = { .type = PTP_CLK_REQ_PPS };
 159         int cnt, enable;
 160         int err = -EINVAL;
 161
 162         if (!capable(CAP_SYS_TIME))
 163                 return -EPERM;
 164
 165         cnt = sscanf(buf, "%d", &enable);
 166         if (cnt != 1)
 167                 goto out;
 168
 169         err = ops->enable(ops, &req, enable ? 1 : 0);
 170         if (err)
 171                 goto out;
 172
 173         return count;
 174 out:
 175         return err;
 176 }
 177
 178 static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
 179 static DEVICE_ATTR(fifo,         0444, extts_fifo_show, NULL);
 180 static DEVICE_ATTR(period,       0220, NULL, period_store);
 181 static DEVICE_ATTR(pps_enable,   0220, NULL, pps_enable_store);
 182
 183 int ptp_cleanup_sysfs(struct ptp_clock *ptp)
 184 {
 185         struct device *dev = ptp->dev;
 186         struct ptp_clock_info *info = ptp->info;
 187
 188         if (info->n_ext_ts) {
 189                 device_remove_file(dev, &dev_attr_extts_enable);
 190                 device_remove_file(dev, &dev_attr_fifo);
 191         }
 192         if (info->n_per_out)
 193                 device_remove_file(dev, &dev_attr_period);
 194
 195         if (info->pps)
 196                 device_remove_file(dev, &dev_attr_pps_enable);
 197
 198         return 0;
 199 }
 200
 201 int ptp_populate_sysfs(struct ptp_clock *ptp)
 202 {
 203         struct device *dev = ptp->dev;
 204         struct ptp_clock_info *info = ptp->info;
 205         int err;
 206
 207         if (info->n_ext_ts) {
 208                 err = device_create_file(dev, &dev_attr_extts_enable);
 209                 if (err)
 210                         goto out1;
 211                 err = device_create_file(dev, &dev_attr_fifo);
 212                 if (err)
 213                         goto out2;
 214         }
 215         if (info->n_per_out) {
 216                 err = device_create_file(dev, &dev_attr_period);
 217                 if (err)
 218                         goto out3;
 219         }
 220         if (info->pps) {
 221                 err = device_create_file(dev, &dev_attr_pps_enable);
 222                 if (err)
 223                         goto out4;
 224         }
 225         return 0;
 226 out4:
 227         if (info->n_per_out)
 228                 device_remove_file(dev, &dev_attr_period);
 229 out3:
 230         if (info->n_ext_ts)
 231                 device_remove_file(dev, &dev_attr_fifo);
 232 out2:
 233         if (info->n_ext_ts)
 234                 device_remove_file(dev, &dev_attr_extts_enable);
 235 out1:
 236         return err;
 237 }