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
  31 #define PTP_SHOW_INT(name)                                              \
  32 static ssize_t name##_show(struct device *dev,                          \
  33                            struct device_attribute *attr, char *page)   \
  34 {                                                                       \
  35         struct ptp_clock *ptp = dev_get_drvdata(dev);                   \
  36         return snprintf(page, PAGE_SIZE-1, "%d\n", ptp->info->name);    \
  37 }
  38
  39 PTP_SHOW_INT(max_adj);
  40 PTP_SHOW_INT(n_alarm);
  41 PTP_SHOW_INT(n_ext_ts);
  42 PTP_SHOW_INT(n_per_out);
  43 PTP_SHOW_INT(pps);
  44
  45 #define PTP_RO_ATTR(_var, _name) {                              \
  46         .attr   = { .name = __stringify(_name), .mode = 0444 }, \
  47         .show   = _var##_show,                                  \
  48 }
  49
  50 struct device_attribute ptp_dev_attrs[] = {
  51         PTP_RO_ATTR(clock_name, clock_name),
  52         PTP_RO_ATTR(max_adj,    max_adjustment),
  53         PTP_RO_ATTR(n_alarm,    n_alarms),
  54         PTP_RO_ATTR(n_ext_ts,   n_external_timestamps),
  55         PTP_RO_ATTR(n_per_out,  n_periodic_outputs),
  56         PTP_RO_ATTR(pps,        pps_available),
  57         __ATTR_NULL,
  58 };
  59
  60 static ssize_t extts_enable_store(struct device *dev,
  61                                   struct device_attribute *attr,
  62                                   const char *buf, size_t count)
  63 {
  64         struct ptp_clock *ptp = dev_get_drvdata(dev);
  65         struct ptp_clock_info *ops = ptp->info;
  66         struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
  67         int cnt, enable;
  68         int err = -EINVAL;
  69
  70         cnt = sscanf(buf, "%u %d", &req.extts.index, &enable);
  71         if (cnt != 2)
  72                 goto out;
  73         if (req.extts.index >= ops->n_ext_ts)
  74                 goto out;
  75
  76         err = ops->enable(ops, &req, enable ? 1 : 0);
  77         if (err)
  78                 goto out;
  79
  80         return count;
  81 out:
  82         return err;
  83 }
  84
  85 static ssize_t extts_fifo_show(struct device *dev,
  86                                struct device_attribute *attr, char *page)
  87 {
  88         struct ptp_clock *ptp = dev_get_drvdata(dev);
  89         struct timestamp_event_queue *queue = &ptp->tsevq;
  90         struct ptp_extts_event event;
  91         unsigned long flags;
  92         size_t qcnt;
  93         int cnt = 0;
  94
  95         memset(&event, 0, sizeof(event));
  96
  97         if (mutex_lock_interruptible(&ptp->tsevq_mux))
  98                 return -ERESTARTSYS;
  99
 100         spin_lock_irqsave(&queue->lock, flags);
 101         qcnt = queue_cnt(queue);
 102         if (qcnt) {
 103                 event = queue->buf[queue->head];
 104                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 105         }
 106         spin_unlock_irqrestore(&queue->lock, flags);
 107
 108         if (!qcnt)
 109                 goto out;
 110
 111         cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
 112                        event.index, event.t.sec, event.t.nsec);
 113 out:
 114         mutex_unlock(&ptp->tsevq_mux);
 115         return cnt;
 116 }
 117
 118 static ssize_t period_store(struct device *dev,
 119                             struct device_attribute *attr,
 120                             const char *buf, size_t count)
 121 {
 122         struct ptp_clock *ptp = dev_get_drvdata(dev);
 123         struct ptp_clock_info *ops = ptp->info;
 124         struct ptp_clock_request req = { .type = PTP_CLK_REQ_PEROUT };
 125         int cnt, enable, err = -EINVAL;
 126
 127         cnt = sscanf(buf, "%u %lld %u %lld %u", &req.perout.index,
 128                      &req.perout.start.sec, &req.perout.start.nsec,
 129                      &req.perout.period.sec, &req.perout.period.nsec);
 130         if (cnt != 5)
 131                 goto out;
 132         if (req.perout.index >= ops->n_per_out)
 133                 goto out;
 134
 135         enable = req.perout.period.sec || req.perout.period.nsec;
 136         err = ops->enable(ops, &req, enable);
 137         if (err)
 138                 goto out;
 139
 140         return count;
 141 out:
 142         return err;
 143 }
 144
 145 static ssize_t pps_enable_store(struct device *dev,
 146                                 struct device_attribute *attr,
 147                                 const char *buf, size_t count)
 148 {
 149         struct ptp_clock *ptp = dev_get_drvdata(dev);
 150         struct ptp_clock_info *ops = ptp->info;
 151         struct ptp_clock_request req = { .type = PTP_CLK_REQ_PPS };
 152         int cnt, enable;
 153         int err = -EINVAL;
 154
 155         if (!capable(CAP_SYS_TIME))
 156                 return -EPERM;
 157
 158         cnt = sscanf(buf, "%d", &enable);
 159         if (cnt != 1)
 160                 goto out;
 161
 162         err = ops->enable(ops, &req, enable ? 1 : 0);
 163         if (err)
 164                 goto out;
 165
 166         return count;
 167 out:
 168         return err;
 169 }
 170
 171 static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
 172 static DEVICE_ATTR(fifo,         0444, extts_fifo_show, NULL);
 173 static DEVICE_ATTR(period,       0220, NULL, period_store);
 174 static DEVICE_ATTR(pps_enable,   0220, NULL, pps_enable_store);
 175
 176 int ptp_cleanup_sysfs(struct ptp_clock *ptp)
 177 {
 178         struct device *dev = ptp->dev;
 179         struct ptp_clock_info *info = ptp->info;
 180
 181         if (info->n_ext_ts) {
 182                 device_remove_file(dev, &dev_attr_extts_enable);
 183                 device_remove_file(dev, &dev_attr_fifo);
 184         }
 185         if (info->n_per_out)
 186                 device_remove_file(dev, &dev_attr_period);
 187
 188         if (info->pps)
 189                 device_remove_file(dev, &dev_attr_pps_enable);
 190
 191         return 0;
 192 }
 193
 194 int ptp_populate_sysfs(struct ptp_clock *ptp)
 195 {
 196         struct device *dev = ptp->dev;
 197         struct ptp_clock_info *info = ptp->info;
 198         int err;
 199
 200         if (info->n_ext_ts) {
 201                 err = device_create_file(dev, &dev_attr_extts_enable);
 202                 if (err)
 203                         goto out1;
 204                 err = device_create_file(dev, &dev_attr_fifo);
 205                 if (err)
 206                         goto out2;
 207         }
 208         if (info->n_per_out) {
 209                 err = device_create_file(dev, &dev_attr_period);
 210                 if (err)
 211                         goto out3;
 212         }
 213         if (info->pps) {
 214                 err = device_create_file(dev, &dev_attr_pps_enable);
 215                 if (err)
 216                         goto out4;
 217         }
 218         return 0;
 219 out4:
 220         if (info->n_per_out)
 221                 device_remove_file(dev, &dev_attr_period);
 222 out3:
 223         if (info->n_ext_ts)
 224                 device_remove_file(dev, &dev_attr_fifo);
 225 out2:
 226         if (info->n_ext_ts)
 227                 device_remove_file(dev, &dev_attr_extts_enable);
 228 out1:
 229         return err;
 230 }