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 #include <linux/slab.h>
  22
  23 #include "ptp_private.h"
  24
  25 static ssize_t clock_name_show(struct device *dev,
  26                                struct device_attribute *attr, char *page)
  27 {
  28         struct ptp_clock *ptp = dev_get_drvdata(dev);
  29         return snprintf(page, PAGE_SIZE-1, "%s\n", ptp->info->name);
  30 }
  31 static DEVICE_ATTR(clock_name, 0444, clock_name_show, NULL);
  32
  33 #define PTP_SHOW_INT(name, var)                                         \
  34 static ssize_t var##_show(struct device *dev,                           \
  35                            struct device_attribute *attr, char *page)   \
  36 {                                                                       \
  37         struct ptp_clock *ptp = dev_get_drvdata(dev);                   \
  38         return snprintf(page, PAGE_SIZE-1, "%d\n", ptp->info->var);     \
  39 }                                                                       \
  40 static DEVICE_ATTR(name, 0444, var##_show, NULL);
  41
  42 PTP_SHOW_INT(max_adjustment, max_adj);
  43 PTP_SHOW_INT(n_alarms, n_alarm);
  44 PTP_SHOW_INT(n_external_timestamps, n_ext_ts);
  45 PTP_SHOW_INT(n_periodic_outputs, n_per_out);
  46 PTP_SHOW_INT(n_programmable_pins, n_pins);
  47 PTP_SHOW_INT(pps_available, pps);
  48
  49 static struct attribute *ptp_attrs[] = {
  50         &dev_attr_clock_name.attr,
  51         &dev_attr_max_adjustment.attr,
  52         &dev_attr_n_alarms.attr,
  53         &dev_attr_n_external_timestamps.attr,
  54         &dev_attr_n_periodic_outputs.attr,
  55         &dev_attr_n_programmable_pins.attr,
  56         &dev_attr_pps_available.attr,
  57         NULL,
  58 };
  59
  60 static const struct attribute_group ptp_group = {
  61         .attrs = ptp_attrs,
  62 };
  63
  64 const struct attribute_group *ptp_groups[] = {
  65         &ptp_group,
  66         NULL,
  67 };
  68
  69
  70 static ssize_t extts_enable_store(struct device *dev,
  71                                   struct device_attribute *attr,
  72                                   const char *buf, size_t count)
  73 {
  74         struct ptp_clock *ptp = dev_get_drvdata(dev);
  75         struct ptp_clock_info *ops = ptp->info;
  76         struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
  77         int cnt, enable;
  78         int err = -EINVAL;
  79
  80         cnt = sscanf(buf, "%u %d", &req.extts.index, &enable);
  81         if (cnt != 2)
  82                 goto out;
  83         if (req.extts.index >= ops->n_ext_ts)
  84                 goto out;
  85
  86         err = ops->enable(ops, &req, enable ? 1 : 0);
  87         if (err)
  88                 goto out;
  89
  90         return count;
  91 out:
  92         return err;
  93 }
  94
  95 static ssize_t extts_fifo_show(struct device *dev,
  96                                struct device_attribute *attr, char *page)
  97 {
  98         struct ptp_clock *ptp = dev_get_drvdata(dev);
  99         struct timestamp_event_queue *queue = &ptp->tsevq;
 100         struct ptp_extts_event event;
 101         unsigned long flags;
 102         size_t qcnt;
 103         int cnt = 0;
 104
 105         memset(&event, 0, sizeof(event));
 106
 107         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 108                 return -ERESTARTSYS;
 109
 110         spin_lock_irqsave(&queue->lock, flags);
 111         qcnt = queue_cnt(queue);
 112         if (qcnt) {
 113                 event = queue->buf[queue->head];
 114                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 115         }
 116         spin_unlock_irqrestore(&queue->lock, flags);
 117
 118         if (!qcnt)
 119                 goto out;
 120
 121         cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
 122                        event.index, event.t.sec, event.t.nsec);
 123 out:
 124         mutex_unlock(&ptp->tsevq_mux);
 125         return cnt;
 126 }
 127
 128 static ssize_t period_store(struct device *dev,
 129                             struct device_attribute *attr,
 130                             const char *buf, size_t count)
 131 {
 132         struct ptp_clock *ptp = dev_get_drvdata(dev);
 133         struct ptp_clock_info *ops = ptp->info;
 134         struct ptp_clock_request req = { .type = PTP_CLK_REQ_PEROUT };
 135         int cnt, enable, err = -EINVAL;
 136
 137         cnt = sscanf(buf, "%u %lld %u %lld %u", &req.perout.index,
 138                      &req.perout.start.sec, &req.perout.start.nsec,
 139                      &req.perout.period.sec, &req.perout.period.nsec);
 140         if (cnt != 5)
 141                 goto out;
 142         if (req.perout.index >= ops->n_per_out)
 143                 goto out;
 144
 145         enable = req.perout.period.sec || req.perout.period.nsec;
 146         err = ops->enable(ops, &req, enable);
 147         if (err)
 148                 goto out;
 149
 150         return count;
 151 out:
 152         return err;
 153 }
 154
 155 static ssize_t pps_enable_store(struct device *dev,
 156                                 struct device_attribute *attr,
 157                                 const char *buf, size_t count)
 158 {
 159         struct ptp_clock *ptp = dev_get_drvdata(dev);
 160         struct ptp_clock_info *ops = ptp->info;
 161         struct ptp_clock_request req = { .type = PTP_CLK_REQ_PPS };
 162         int cnt, enable;
 163         int err = -EINVAL;
 164
 165         if (!capable(CAP_SYS_TIME))
 166                 return -EPERM;
 167
 168         cnt = sscanf(buf, "%d", &enable);
 169         if (cnt != 1)
 170                 goto out;
 171
 172         err = ops->enable(ops, &req, enable ? 1 : 0);
 173         if (err)
 174                 goto out;
 175
 176         return count;
 177 out:
 178         return err;
 179 }
 180
 181 static int ptp_pin_name2index(struct ptp_clock *ptp, const char *name)
 182 {
 183         int i;
 184         for (i = 0; i < ptp->info->n_pins; i++) {
 185                 if (!strcmp(ptp->info->pin_config[i].name, name))
 186                         return i;
 187         }
 188         return -1;
 189 }
 190
 191 static ssize_t ptp_pin_show(struct device *dev, struct device_attribute *attr,
 192                             char *page)
 193 {
 194         struct ptp_clock *ptp = dev_get_drvdata(dev);
 195         unsigned int func, chan;
 196         int index;
 197
 198         index = ptp_pin_name2index(ptp, attr->attr.name);
 199         if (index < 0)
 200                 return -EINVAL;
 201
 202         if (mutex_lock_interruptible(&ptp->pincfg_mux))
 203                 return -ERESTARTSYS;
 204
 205         func = ptp->info->pin_config[index].func;
 206         chan = ptp->info->pin_config[index].chan;
 207
 208         mutex_unlock(&ptp->pincfg_mux);
 209
 210         return snprintf(page, PAGE_SIZE, "%u %u\n", func, chan);
 211 }
 212
 213 static ssize_t ptp_pin_store(struct device *dev, struct device_attribute *attr,
 214                              const char *buf, size_t count)
 215 {
 216         struct ptp_clock *ptp = dev_get_drvdata(dev);
 217         unsigned int func, chan;
 218         int cnt, err, index;
 219
 220         cnt = sscanf(buf, "%u %u", &func, &chan);
 221         if (cnt != 2)
 222                 return -EINVAL;
 223
 224         index = ptp_pin_name2index(ptp, attr->attr.name);
 225         if (index < 0)
 226                 return -EINVAL;
 227
 228         if (mutex_lock_interruptible(&ptp->pincfg_mux))
 229                 return -ERESTARTSYS;
 230         err = ptp_set_pinfunc(ptp, index, func, chan);
 231         mutex_unlock(&ptp->pincfg_mux);
 232         if (err)
 233                 return err;
 234
 235         return count;
 236 }
 237
 238 static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
 239 static DEVICE_ATTR(fifo,         0444, extts_fifo_show, NULL);
 240 static DEVICE_ATTR(period,       0220, NULL, period_store);
 241 static DEVICE_ATTR(pps_enable,   0220, NULL, pps_enable_store);
 242
 243 int ptp_cleanup_sysfs(struct ptp_clock *ptp)
 244 {
 245         struct device *dev = ptp->dev;
 246         struct ptp_clock_info *info = ptp->info;
 247
 248         if (info->n_ext_ts) {
 249                 device_remove_file(dev, &dev_attr_extts_enable);
 250                 device_remove_file(dev, &dev_attr_fifo);
 251         }
 252         if (info->n_per_out)
 253                 device_remove_file(dev, &dev_attr_period);
 254
 255         if (info->pps)
 256                 device_remove_file(dev, &dev_attr_pps_enable);
 257
 258         if (info->n_pins) {
 259                 sysfs_remove_group(&dev->kobj, &ptp->pin_attr_group);
 260                 kfree(ptp->pin_attr);
 261                 kfree(ptp->pin_dev_attr);
 262         }
 263         return 0;
 264 }
 265
 266 static int ptp_populate_pins(struct ptp_clock *ptp)
 267 {
 268         struct device *dev = ptp->dev;
 269         struct ptp_clock_info *info = ptp->info;
 270         int err = -ENOMEM, i, n_pins = info->n_pins;
 271
 272         ptp->pin_dev_attr = kzalloc(n_pins * sizeof(*ptp->pin_dev_attr),
 273                                     GFP_KERNEL);
 274         if (!ptp->pin_dev_attr)
 275                 goto no_dev_attr;
 276
 277         ptp->pin_attr = kzalloc((1 + n_pins) * sizeof(struct attribute *),
 278                                 GFP_KERNEL);
 279         if (!ptp->pin_attr)
 280                 goto no_pin_attr;
 281
 282         for (i = 0; i < n_pins; i++) {
 283                 struct device_attribute *da = &ptp->pin_dev_attr[i];
 284                 sysfs_attr_init(&da->attr);
 285                 da->attr.name = info->pin_config[i].name;
 286                 da->attr.mode = 0644;
 287                 da->show = ptp_pin_show;
 288                 da->store = ptp_pin_store;
 289                 ptp->pin_attr[i] = &da->attr;
 290         }
 291
 292         ptp->pin_attr_group.name = "pins";
 293         ptp->pin_attr_group.attrs = ptp->pin_attr;
 294
 295         err = sysfs_create_group(&dev->kobj, &ptp->pin_attr_group);
 296         if (err)
 297                 goto no_group;
 298         return 0;
 299
 300 no_group:
 301         kfree(ptp->pin_attr);
 302 no_pin_attr:
 303         kfree(ptp->pin_dev_attr);
 304 no_dev_attr:
 305         return err;
 306 }
 307
 308 int ptp_populate_sysfs(struct ptp_clock *ptp)
 309 {
 310         struct device *dev = ptp->dev;
 311         struct ptp_clock_info *info = ptp->info;
 312         int err;
 313
 314         if (info->n_ext_ts) {
 315                 err = device_create_file(dev, &dev_attr_extts_enable);
 316                 if (err)
 317                         goto out1;
 318                 err = device_create_file(dev, &dev_attr_fifo);
 319                 if (err)
 320                         goto out2;
 321         }
 322         if (info->n_per_out) {
 323                 err = device_create_file(dev, &dev_attr_period);
 324                 if (err)
 325                         goto out3;
 326         }
 327         if (info->pps) {
 328                 err = device_create_file(dev, &dev_attr_pps_enable);
 329                 if (err)
 330                         goto out4;
 331         }
 332         if (info->n_pins) {
 333                 err = ptp_populate_pins(ptp);
 334                 if (err)
 335                         goto out5;
 336         }
 337         return 0;
 338 out5:
 339         if (info->pps)
 340                 device_remove_file(dev, &dev_attr_pps_enable);
 341 out4:
 342         if (info->n_per_out)
 343                 device_remove_file(dev, &dev_attr_period);
 344 out3:
 345         if (info->n_ext_ts)
 346                 device_remove_file(dev, &dev_attr_fifo);
 347 out2:
 348         if (info->n_ext_ts)
 349                 device_remove_file(dev, &dev_attr_extts_enable);
 350 out1:
 351         return err;
 352 }