linux/drivers/ptp/ptp_sysfs.c
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   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
  12static 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 snprintf(page, PAGE_SIZE-1, "%s\n", ptp->info->name);
  17}
  18static DEVICE_ATTR_RO(clock_name);
  19
  20#define PTP_SHOW_INT(name, var)                                         \
  21static 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}                                                                       \
  27static DEVICE_ATTR(name, 0444, var##_show, NULL);
  28
  29PTP_SHOW_INT(max_adjustment, max_adj);
  30PTP_SHOW_INT(n_alarms, n_alarm);
  31PTP_SHOW_INT(n_external_timestamps, n_ext_ts);
  32PTP_SHOW_INT(n_periodic_outputs, n_per_out);
  33PTP_SHOW_INT(n_programmable_pins, n_pins);
  34PTP_SHOW_INT(pps_available, pps);
  35
  36static 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;
  57out:
  58        return err;
  59}
  60static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
  61
  62static 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                queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
  82        }
  83        spin_unlock_irqrestore(&queue->lock, flags);
  84
  85        if (!qcnt)
  86                goto out;
  87
  88        cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
  89                       event.index, event.t.sec, event.t.nsec);
  90out:
  91        mutex_unlock(&ptp->tsevq_mux);
  92        return cnt;
  93}
  94static DEVICE_ATTR(fifo, 0444, extts_fifo_show, NULL);
  95
  96static ssize_t period_store(struct device *dev,
  97                            struct device_attribute *attr,
  98                            const char *buf, size_t count)
  99{
 100        struct ptp_clock *ptp = dev_get_drvdata(dev);
 101        struct ptp_clock_info *ops = ptp->info;
 102        struct ptp_clock_request req = { .type = PTP_CLK_REQ_PEROUT };
 103        int cnt, enable, err = -EINVAL;
 104
 105        cnt = sscanf(buf, "%u %lld %u %lld %u", &req.perout.index,
 106                     &req.perout.start.sec, &req.perout.start.nsec,
 107                     &req.perout.period.sec, &req.perout.period.nsec);
 108        if (cnt != 5)
 109                goto out;
 110        if (req.perout.index >= ops->n_per_out)
 111                goto out;
 112
 113        enable = req.perout.period.sec || req.perout.period.nsec;
 114        err = ops->enable(ops, &req, enable);
 115        if (err)
 116                goto out;
 117
 118        return count;
 119out:
 120        return err;
 121}
 122static DEVICE_ATTR(period, 0220, NULL, period_store);
 123
 124static ssize_t pps_enable_store(struct device *dev,
 125                                struct device_attribute *attr,
 126                                const char *buf, size_t count)
 127{
 128        struct ptp_clock *ptp = dev_get_drvdata(dev);
 129        struct ptp_clock_info *ops = ptp->info;
 130        struct ptp_clock_request req = { .type = PTP_CLK_REQ_PPS };
 131        int cnt, enable;
 132        int err = -EINVAL;
 133
 134        if (!capable(CAP_SYS_TIME))
 135                return -EPERM;
 136
 137        cnt = sscanf(buf, "%d", &enable);
 138        if (cnt != 1)
 139                goto out;
 140
 141        err = ops->enable(ops, &req, enable ? 1 : 0);
 142        if (err)
 143                goto out;
 144
 145        return count;
 146out:
 147        return err;
 148}
 149static DEVICE_ATTR(pps_enable, 0220, NULL, pps_enable_store);
 150
 151static struct attribute *ptp_attrs[] = {
 152        &dev_attr_clock_name.attr,
 153
 154        &dev_attr_max_adjustment.attr,
 155        &dev_attr_n_alarms.attr,
 156        &dev_attr_n_external_timestamps.attr,
 157        &dev_attr_n_periodic_outputs.attr,
 158        &dev_attr_n_programmable_pins.attr,
 159        &dev_attr_pps_available.attr,
 160
 161        &dev_attr_extts_enable.attr,
 162        &dev_attr_fifo.attr,
 163        &dev_attr_period.attr,
 164        &dev_attr_pps_enable.attr,
 165        NULL
 166};
 167
 168static umode_t ptp_is_attribute_visible(struct kobject *kobj,
 169                                        struct attribute *attr, int n)
 170{
 171        struct device *dev = kobj_to_dev(kobj);
 172        struct ptp_clock *ptp = dev_get_drvdata(dev);
 173        struct ptp_clock_info *info = ptp->info;
 174        umode_t mode = attr->mode;
 175
 176        if (attr == &dev_attr_extts_enable.attr ||
 177            attr == &dev_attr_fifo.attr) {
 178                if (!info->n_ext_ts)
 179                        mode = 0;
 180        } else if (attr == &dev_attr_period.attr) {
 181                if (!info->n_per_out)
 182                        mode = 0;
 183        } else if (attr == &dev_attr_pps_enable.attr) {
 184                if (!info->pps)
 185                        mode = 0;
 186        }
 187
 188        return mode;
 189}
 190
 191static const struct attribute_group ptp_group = {
 192        .is_visible     = ptp_is_attribute_visible,
 193        .attrs          = ptp_attrs,
 194};
 195
 196const struct attribute_group *ptp_groups[] = {
 197        &ptp_group,
 198        NULL
 199};
 200
 201static int ptp_pin_name2index(struct ptp_clock *ptp, const char *name)
 202{
 203        int i;
 204        for (i = 0; i < ptp->info->n_pins; i++) {
 205                if (!strcmp(ptp->info->pin_config[i].name, name))
 206                        return i;
 207        }
 208        return -1;
 209}
 210
 211static ssize_t ptp_pin_show(struct device *dev, struct device_attribute *attr,
 212                            char *page)
 213{
 214        struct ptp_clock *ptp = dev_get_drvdata(dev);
 215        unsigned int func, chan;
 216        int index;
 217
 218        index = ptp_pin_name2index(ptp, attr->attr.name);
 219        if (index < 0)
 220                return -EINVAL;
 221
 222        if (mutex_lock_interruptible(&ptp->pincfg_mux))
 223                return -ERESTARTSYS;
 224
 225        func = ptp->info->pin_config[index].func;
 226        chan = ptp->info->pin_config[index].chan;
 227
 228        mutex_unlock(&ptp->pincfg_mux);
 229
 230        return snprintf(page, PAGE_SIZE, "%u %u\n", func, chan);
 231}
 232
 233static ssize_t ptp_pin_store(struct device *dev, struct device_attribute *attr,
 234                             const char *buf, size_t count)
 235{
 236        struct ptp_clock *ptp = dev_get_drvdata(dev);
 237        unsigned int func, chan;
 238        int cnt, err, index;
 239
 240        cnt = sscanf(buf, "%u %u", &func, &chan);
 241        if (cnt != 2)
 242                return -EINVAL;
 243
 244        index = ptp_pin_name2index(ptp, attr->attr.name);
 245        if (index < 0)
 246                return -EINVAL;
 247
 248        if (mutex_lock_interruptible(&ptp->pincfg_mux))
 249                return -ERESTARTSYS;
 250        err = ptp_set_pinfunc(ptp, index, func, chan);
 251        mutex_unlock(&ptp->pincfg_mux);
 252        if (err)
 253                return err;
 254
 255        return count;
 256}
 257
 258int ptp_populate_pin_groups(struct ptp_clock *ptp)
 259{
 260        struct ptp_clock_info *info = ptp->info;
 261        int err = -ENOMEM, i, n_pins = info->n_pins;
 262
 263        if (!n_pins)
 264                return 0;
 265
 266        ptp->pin_dev_attr = kcalloc(n_pins, sizeof(*ptp->pin_dev_attr),
 267                                    GFP_KERNEL);
 268        if (!ptp->pin_dev_attr)
 269                goto no_dev_attr;
 270
 271        ptp->pin_attr = kcalloc(1 + n_pins, sizeof(*ptp->pin_attr), GFP_KERNEL);
 272        if (!ptp->pin_attr)
 273                goto no_pin_attr;
 274
 275        for (i = 0; i < n_pins; i++) {
 276                struct device_attribute *da = &ptp->pin_dev_attr[i];
 277                sysfs_attr_init(&da->attr);
 278                da->attr.name = info->pin_config[i].name;
 279                da->attr.mode = 0644;
 280                da->show = ptp_pin_show;
 281                da->store = ptp_pin_store;
 282                ptp->pin_attr[i] = &da->attr;
 283        }
 284
 285        ptp->pin_attr_group.name = "pins";
 286        ptp->pin_attr_group.attrs = ptp->pin_attr;
 287
 288        ptp->pin_attr_groups[0] = &ptp->pin_attr_group;
 289
 290        return 0;
 291
 292no_pin_attr:
 293        kfree(ptp->pin_dev_attr);
 294no_dev_attr:
 295        return err;
 296}
 297
 298void ptp_cleanup_pin_groups(struct ptp_clock *ptp)
 299{
 300        kfree(ptp->pin_attr);
 301        kfree(ptp->pin_dev_attr);
 302}
 303