drivers/ptp/ptp_sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * PTP 1588 clock support - sysfs interface.
   4  *
   5  * Copyright (C) 2010 OMICRON electronics GmbH
   6  */
   7 #include <linux/capability.h>
   8 #include <linux/slab.h>
   9
  10 #include "ptp_private.h"
  11
  12 static ssize_t clock_name_show(struct device *dev,
  13                                struct device_attribute *attr, char *page)
  14 {
  15         struct ptp_clock *ptp = dev_get_drvdata(dev);
  16         return sysfs_emit(page, "%s\n", ptp->info->name);
  17 }
  18 static DEVICE_ATTR_RO(clock_name);
  19
  20 #define PTP_SHOW_INT(name, var)                                         \
  21 static ssize_t var##_show(struct device *dev,                           \
  22                            struct device_attribute *attr, char *page)   \
  23 {                                                                       \
  24         struct ptp_clock *ptp = dev_get_drvdata(dev);                   \
  25         return snprintf(page, PAGE_SIZE-1, "%d\n", ptp->info->var);     \
  26 }                                                                       \
  27 static DEVICE_ATTR(name, 0444, var##_show, NULL);
  28
  29 PTP_SHOW_INT(max_adjustment, max_adj);
  30 PTP_SHOW_INT(n_alarms, n_alarm);
  31 PTP_SHOW_INT(n_external_timestamps, n_ext_ts);
  32 PTP_SHOW_INT(n_periodic_outputs, n_per_out);
  33 PTP_SHOW_INT(n_programmable_pins, n_pins);
  34 PTP_SHOW_INT(pps_available, pps);
  35
  36 static ssize_t extts_enable_store(struct device *dev,
  37                                   struct device_attribute *attr,
  38                                   const char *buf, size_t count)
  39 {
  40         struct ptp_clock *ptp = dev_get_drvdata(dev);
  41         struct ptp_clock_info *ops = ptp->info;
  42         struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
  43         int cnt, enable;
  44         int err = -EINVAL;
  45
  46         cnt = sscanf(buf, "%u %d", &req.extts.index, &enable);
  47         if (cnt != 2)
  48                 goto out;
  49         if (req.extts.index >= ops->n_ext_ts)
  50                 goto out;
  51
  52         err = ops->enable(ops, &req, enable ? 1 : 0);
  53         if (err)
  54                 goto out;
  55
  56         return count;
  57 out:
  58         return err;
  59 }
  60 static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
  61
  62 static ssize_t extts_fifo_show(struct device *dev,
  63                                struct device_attribute *attr, char *page)
  64 {
  65         struct ptp_clock *ptp = dev_get_drvdata(dev);
  66         struct timestamp_event_queue *queue = &ptp->tsevq;
  67         struct ptp_extts_event event;
  68         unsigned long flags;
  69         size_t qcnt;
  70         int cnt = 0;
  71
  72         memset(&event, 0, sizeof(event));
  73
  74         if (mutex_lock_interruptible(&ptp->tsevq_mux))
  75                 return -ERESTARTSYS;
  76
  77         spin_lock_irqsave(&queue->lock, flags);
  78         qcnt = queue_cnt(queue);
  79         if (qcnt) {
  80                 event = queue->buf[queue->head];
  81                 /* Paired with READ_ONCE() in queue_cnt() */
  82                 WRITE_ONCE(queue->head, (queue->head + 1) % PTP_MAX_TIMESTAMPS);
  83         }
  84         spin_unlock_irqrestore(&queue->lock, flags);
  85
  86         if (!qcnt)
  87                 goto out;
  88
  89         cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
  90                        event.index, event.t.sec, event.t.nsec);
  91 out:
  92         mutex_unlock(&ptp->tsevq_mux);
  93         return cnt;
  94 }
  95 static DEVICE_ATTR(fifo, 0444, extts_fifo_show, NULL);
  96
  97 static ssize_t period_store(struct device *dev,
  98                             struct device_attribute *attr,
  99                             const char *buf, size_t count)
 100 {
 101         struct ptp_clock *ptp = dev_get_drvdata(dev);
 102         struct ptp_clock_info *ops = ptp->info;
 103         struct ptp_clock_request req = { .type = PTP_CLK_REQ_PEROUT };
 104         int cnt, enable, err = -EINVAL;
 105
 106         cnt = sscanf(buf, "%u %lld %u %lld %u", &req.perout.index,
 107                      &req.perout.start.sec, &req.perout.start.nsec,
 108                      &req.perout.period.sec, &req.perout.period.nsec);
 109         if (cnt != 5)
 110                 goto out;
 111         if (req.perout.index >= ops->n_per_out)
 112                 goto out;
 113
 114         enable = req.perout.period.sec || req.perout.period.nsec;
 115         err = ops->enable(ops, &req, enable);
 116         if (err)
 117                 goto out;
 118
 119         return count;
 120 out:
 121         return err;
 122 }
 123 static DEVICE_ATTR(period, 0220, NULL, period_store);
 124
 125 static ssize_t pps_enable_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_PPS };
 132         int cnt, enable;
 133         int err = -EINVAL;
 134
 135         if (!capable(CAP_SYS_TIME))
 136                 return -EPERM;
 137
 138         cnt = sscanf(buf, "%d", &enable);
 139         if (cnt != 1)
 140                 goto out;
 141
 142         err = ops->enable(ops, &req, enable ? 1 : 0);
 143         if (err)
 144                 goto out;
 145
 146         return count;
 147 out:
 148         return err;
 149 }
 150 static DEVICE_ATTR(pps_enable, 0220, NULL, pps_enable_store);
 151
 152 static struct attribute *ptp_attrs[] = {
 153         &dev_attr_clock_name.attr,
 154
 155         &dev_attr_max_adjustment.attr,
 156         &dev_attr_n_alarms.attr,
 157         &dev_attr_n_external_timestamps.attr,
 158         &dev_attr_n_periodic_outputs.attr,
 159         &dev_attr_n_programmable_pins.attr,
 160         &dev_attr_pps_available.attr,
 161
 162         &dev_attr_extts_enable.attr,
 163         &dev_attr_fifo.attr,
 164         &dev_attr_period.attr,
 165         &dev_attr_pps_enable.attr,
 166         NULL
 167 };
 168
 169 static umode_t ptp_is_attribute_visible(struct kobject *kobj,
 170                                         struct attribute *attr, int n)
 171 {
 172         struct device *dev = kobj_to_dev(kobj);
 173         struct ptp_clock *ptp = dev_get_drvdata(dev);
 174         struct ptp_clock_info *info = ptp->info;
 175         umode_t mode = attr->mode;
 176
 177         if (attr == &dev_attr_extts_enable.attr ||
 178             attr == &dev_attr_fifo.attr) {
 179                 if (!info->n_ext_ts)
 180                         mode = 0;
 181         } else if (attr == &dev_attr_period.attr) {
 182                 if (!info->n_per_out)
 183                         mode = 0;
 184         } else if (attr == &dev_attr_pps_enable.attr) {
 185                 if (!info->pps)
 186                         mode = 0;
 187         }
 188
 189         return mode;
 190 }
 191
 192 static const struct attribute_group ptp_group = {
 193         .is_visible     = ptp_is_attribute_visible,
 194         .attrs          = ptp_attrs,
 195 };
 196
 197 const struct attribute_group *ptp_groups[] = {
 198         &ptp_group,
 199         NULL
 200 };
 201
 202 static int ptp_pin_name2index(struct ptp_clock *ptp, const char *name)
 203 {
 204         int i;
 205         for (i = 0; i < ptp->info->n_pins; i++) {
 206                 if (!strcmp(ptp->info->pin_config[i].name, name))
 207                         return i;
 208         }
 209         return -1;
 210 }
 211
 212 static ssize_t ptp_pin_show(struct device *dev, struct device_attribute *attr,
 213                             char *page)
 214 {
 215         struct ptp_clock *ptp = dev_get_drvdata(dev);
 216         unsigned int func, chan;
 217         int index;
 218
 219         index = ptp_pin_name2index(ptp, attr->attr.name);
 220         if (index < 0)
 221                 return -EINVAL;
 222
 223         if (mutex_lock_interruptible(&ptp->pincfg_mux))
 224                 return -ERESTARTSYS;
 225
 226         func = ptp->info->pin_config[index].func;
 227         chan = ptp->info->pin_config[index].chan;
 228
 229         mutex_unlock(&ptp->pincfg_mux);
 230
 231         return sysfs_emit(page, "%u %u\n", func, chan);
 232 }
 233
 234 static ssize_t ptp_pin_store(struct device *dev, struct device_attribute *attr,
 235                              const char *buf, size_t count)
 236 {
 237         struct ptp_clock *ptp = dev_get_drvdata(dev);
 238         unsigned int func, chan;
 239         int cnt, err, index;
 240
 241         cnt = sscanf(buf, "%u %u", &func, &chan);
 242         if (cnt != 2)
 243                 return -EINVAL;
 244
 245         index = ptp_pin_name2index(ptp, attr->attr.name);
 246         if (index < 0)
 247                 return -EINVAL;
 248
 249         if (mutex_lock_interruptible(&ptp->pincfg_mux))
 250                 return -ERESTARTSYS;
 251         err = ptp_set_pinfunc(ptp, index, func, chan);
 252         mutex_unlock(&ptp->pincfg_mux);
 253         if (err)
 254                 return err;
 255
 256         return count;
 257 }
 258
 259 int ptp_populate_pin_groups(struct ptp_clock *ptp)
 260 {
 261         struct ptp_clock_info *info = ptp->info;
 262         int err = -ENOMEM, i, n_pins = info->n_pins;
 263
 264         if (!n_pins)
 265                 return 0;
 266
 267         ptp->pin_dev_attr = kcalloc(n_pins, sizeof(*ptp->pin_dev_attr),
 268                                     GFP_KERNEL);
 269         if (!ptp->pin_dev_attr)
 270                 goto no_dev_attr;
 271
 272         ptp->pin_attr = kcalloc(1 + n_pins, sizeof(*ptp->pin_attr), GFP_KERNEL);
 273         if (!ptp->pin_attr)
 274                 goto no_pin_attr;
 275
 276         for (i = 0; i < n_pins; i++) {
 277                 struct device_attribute *da = &ptp->pin_dev_attr[i];
 278                 sysfs_attr_init(&da->attr);
 279                 da->attr.name = info->pin_config[i].name;
 280                 da->attr.mode = 0644;
 281                 da->show = ptp_pin_show;
 282                 da->store = ptp_pin_store;
 283                 ptp->pin_attr[i] = &da->attr;
 284         }
 285
 286         ptp->pin_attr_group.name = "pins";
 287         ptp->pin_attr_group.attrs = ptp->pin_attr;
 288
 289         ptp->pin_attr_groups[0] = &ptp->pin_attr_group;
 290
 291         return 0;
 292
 293 no_pin_attr:
 294         kfree(ptp->pin_dev_attr);
 295 no_dev_attr:
 296         return err;
 297 }
 298
 299 void ptp_cleanup_pin_groups(struct ptp_clock *ptp)
 300 {
 301         kfree(ptp->pin_attr);
 302         kfree(ptp->pin_dev_attr);
 303 }