xref: /openbmc/linux/drivers/ptp/ptp_sysfs.c (revision be2b81b5)
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  * Copyright 2021 NXP
7  */
8 #include <linux/capability.h>
9 #include <linux/slab.h>
10 
11 #include "ptp_private.h"
12 
13 static ssize_t clock_name_show(struct device *dev,
14 			       struct device_attribute *attr, char *page)
15 {
16 	struct ptp_clock *ptp = dev_get_drvdata(dev);
17 	return sysfs_emit(page, "%s\n", ptp->info->name);
18 }
19 static DEVICE_ATTR_RO(clock_name);
20 
21 #define PTP_SHOW_INT(name, var)						\
22 static ssize_t var##_show(struct device *dev,				\
23 			   struct device_attribute *attr, char *page)	\
24 {									\
25 	struct ptp_clock *ptp = dev_get_drvdata(dev);			\
26 	return snprintf(page, PAGE_SIZE-1, "%d\n", ptp->info->var);	\
27 }									\
28 static DEVICE_ATTR(name, 0444, var##_show, NULL);
29 
30 PTP_SHOW_INT(max_adjustment, max_adj);
31 PTP_SHOW_INT(n_alarms, n_alarm);
32 PTP_SHOW_INT(n_external_timestamps, n_ext_ts);
33 PTP_SHOW_INT(n_periodic_outputs, n_per_out);
34 PTP_SHOW_INT(n_programmable_pins, n_pins);
35 PTP_SHOW_INT(pps_available, pps);
36 
37 static ssize_t extts_enable_store(struct device *dev,
38 				  struct device_attribute *attr,
39 				  const char *buf, size_t count)
40 {
41 	struct ptp_clock *ptp = dev_get_drvdata(dev);
42 	struct ptp_clock_info *ops = ptp->info;
43 	struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
44 	int cnt, enable;
45 	int err = -EINVAL;
46 
47 	cnt = sscanf(buf, "%u %d", &req.extts.index, &enable);
48 	if (cnt != 2)
49 		goto out;
50 	if (req.extts.index >= ops->n_ext_ts)
51 		goto out;
52 
53 	err = ops->enable(ops, &req, enable ? 1 : 0);
54 	if (err)
55 		goto out;
56 
57 	return count;
58 out:
59 	return err;
60 }
61 static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
62 
63 static ssize_t extts_fifo_show(struct device *dev,
64 			       struct device_attribute *attr, char *page)
65 {
66 	struct ptp_clock *ptp = dev_get_drvdata(dev);
67 	struct timestamp_event_queue *queue = &ptp->tsevq;
68 	struct ptp_extts_event event;
69 	unsigned long flags;
70 	size_t qcnt;
71 	int cnt = 0;
72 
73 	memset(&event, 0, sizeof(event));
74 
75 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
76 		return -ERESTARTSYS;
77 
78 	spin_lock_irqsave(&queue->lock, flags);
79 	qcnt = queue_cnt(queue);
80 	if (qcnt) {
81 		event = queue->buf[queue->head];
82 		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 int unregister_vclock(struct device *dev, void *data)
153 {
154 	struct ptp_clock *ptp = dev_get_drvdata(dev);
155 	struct ptp_clock_info *info = ptp->info;
156 	struct ptp_vclock *vclock;
157 	u32 *num = data;
158 
159 	vclock = info_to_vclock(info);
160 	dev_info(dev->parent, "delete virtual clock ptp%d\n",
161 		 vclock->clock->index);
162 
163 	ptp_vclock_unregister(vclock);
164 	(*num)--;
165 
166 	/* For break. Not error. */
167 	if (*num == 0)
168 		return -EINVAL;
169 
170 	return 0;
171 }
172 
173 static ssize_t n_vclocks_show(struct device *dev,
174 			      struct device_attribute *attr, char *page)
175 {
176 	struct ptp_clock *ptp = dev_get_drvdata(dev);
177 	ssize_t size;
178 
179 	if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
180 		return -ERESTARTSYS;
181 
182 	size = snprintf(page, PAGE_SIZE - 1, "%u\n", ptp->n_vclocks);
183 
184 	mutex_unlock(&ptp->n_vclocks_mux);
185 
186 	return size;
187 }
188 
189 static ssize_t n_vclocks_store(struct device *dev,
190 			       struct device_attribute *attr,
191 			       const char *buf, size_t count)
192 {
193 	struct ptp_clock *ptp = dev_get_drvdata(dev);
194 	struct ptp_vclock *vclock;
195 	int err = -EINVAL;
196 	u32 num, i;
197 
198 	if (kstrtou32(buf, 0, &num))
199 		return err;
200 
201 	if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
202 		return -ERESTARTSYS;
203 
204 	if (num > ptp->max_vclocks) {
205 		dev_err(dev, "max value is %d\n", ptp->max_vclocks);
206 		goto out;
207 	}
208 
209 	/* Need to create more vclocks */
210 	if (num > ptp->n_vclocks) {
211 		for (i = 0; i < num - ptp->n_vclocks; i++) {
212 			vclock = ptp_vclock_register(ptp);
213 			if (!vclock)
214 				goto out;
215 
216 			*(ptp->vclock_index + ptp->n_vclocks + i) =
217 				vclock->clock->index;
218 
219 			dev_info(dev, "new virtual clock ptp%d\n",
220 				 vclock->clock->index);
221 		}
222 	}
223 
224 	/* Need to delete vclocks */
225 	if (num < ptp->n_vclocks) {
226 		i = ptp->n_vclocks - num;
227 		device_for_each_child_reverse(dev, &i,
228 					      unregister_vclock);
229 
230 		for (i = 1; i <= ptp->n_vclocks - num; i++)
231 			*(ptp->vclock_index + ptp->n_vclocks - i) = -1;
232 	}
233 
234 	/* Need to inform about changed physical clock behavior */
235 	if (!ptp->has_cycles) {
236 		if (num == 0)
237 			dev_info(dev, "only physical clock in use now\n");
238 		else
239 			dev_info(dev, "guarantee physical clock free running\n");
240 	}
241 
242 	ptp->n_vclocks = num;
243 	mutex_unlock(&ptp->n_vclocks_mux);
244 
245 	return count;
246 out:
247 	mutex_unlock(&ptp->n_vclocks_mux);
248 	return err;
249 }
250 static DEVICE_ATTR_RW(n_vclocks);
251 
252 static ssize_t max_vclocks_show(struct device *dev,
253 				struct device_attribute *attr, char *page)
254 {
255 	struct ptp_clock *ptp = dev_get_drvdata(dev);
256 	ssize_t size;
257 
258 	size = snprintf(page, PAGE_SIZE - 1, "%u\n", ptp->max_vclocks);
259 
260 	return size;
261 }
262 
263 static ssize_t max_vclocks_store(struct device *dev,
264 				 struct device_attribute *attr,
265 				 const char *buf, size_t count)
266 {
267 	struct ptp_clock *ptp = dev_get_drvdata(dev);
268 	unsigned int *vclock_index;
269 	int err = -EINVAL;
270 	size_t size;
271 	u32 max;
272 
273 	if (kstrtou32(buf, 0, &max) || max == 0)
274 		return -EINVAL;
275 
276 	if (max == ptp->max_vclocks)
277 		return count;
278 
279 	if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
280 		return -ERESTARTSYS;
281 
282 	if (max < ptp->n_vclocks)
283 		goto out;
284 
285 	size = sizeof(int) * max;
286 	vclock_index = kzalloc(size, GFP_KERNEL);
287 	if (!vclock_index) {
288 		err = -ENOMEM;
289 		goto out;
290 	}
291 
292 	size = sizeof(int) * ptp->n_vclocks;
293 	memcpy(vclock_index, ptp->vclock_index, size);
294 
295 	kfree(ptp->vclock_index);
296 	ptp->vclock_index = vclock_index;
297 	ptp->max_vclocks = max;
298 
299 	mutex_unlock(&ptp->n_vclocks_mux);
300 
301 	return count;
302 out:
303 	mutex_unlock(&ptp->n_vclocks_mux);
304 	return err;
305 }
306 static DEVICE_ATTR_RW(max_vclocks);
307 
308 static struct attribute *ptp_attrs[] = {
309 	&dev_attr_clock_name.attr,
310 
311 	&dev_attr_max_adjustment.attr,
312 	&dev_attr_n_alarms.attr,
313 	&dev_attr_n_external_timestamps.attr,
314 	&dev_attr_n_periodic_outputs.attr,
315 	&dev_attr_n_programmable_pins.attr,
316 	&dev_attr_pps_available.attr,
317 
318 	&dev_attr_extts_enable.attr,
319 	&dev_attr_fifo.attr,
320 	&dev_attr_period.attr,
321 	&dev_attr_pps_enable.attr,
322 	&dev_attr_n_vclocks.attr,
323 	&dev_attr_max_vclocks.attr,
324 	NULL
325 };
326 
327 static umode_t ptp_is_attribute_visible(struct kobject *kobj,
328 					struct attribute *attr, int n)
329 {
330 	struct device *dev = kobj_to_dev(kobj);
331 	struct ptp_clock *ptp = dev_get_drvdata(dev);
332 	struct ptp_clock_info *info = ptp->info;
333 	umode_t mode = attr->mode;
334 
335 	if (attr == &dev_attr_extts_enable.attr ||
336 	    attr == &dev_attr_fifo.attr) {
337 		if (!info->n_ext_ts)
338 			mode = 0;
339 	} else if (attr == &dev_attr_period.attr) {
340 		if (!info->n_per_out)
341 			mode = 0;
342 	} else if (attr == &dev_attr_pps_enable.attr) {
343 		if (!info->pps)
344 			mode = 0;
345 	} else if (attr == &dev_attr_n_vclocks.attr ||
346 		   attr == &dev_attr_max_vclocks.attr) {
347 		if (ptp->is_virtual_clock)
348 			mode = 0;
349 	}
350 
351 	return mode;
352 }
353 
354 static const struct attribute_group ptp_group = {
355 	.is_visible	= ptp_is_attribute_visible,
356 	.attrs		= ptp_attrs,
357 };
358 
359 const struct attribute_group *ptp_groups[] = {
360 	&ptp_group,
361 	NULL
362 };
363 
364 static int ptp_pin_name2index(struct ptp_clock *ptp, const char *name)
365 {
366 	int i;
367 	for (i = 0; i < ptp->info->n_pins; i++) {
368 		if (!strcmp(ptp->info->pin_config[i].name, name))
369 			return i;
370 	}
371 	return -1;
372 }
373 
374 static ssize_t ptp_pin_show(struct device *dev, struct device_attribute *attr,
375 			    char *page)
376 {
377 	struct ptp_clock *ptp = dev_get_drvdata(dev);
378 	unsigned int func, chan;
379 	int index;
380 
381 	index = ptp_pin_name2index(ptp, attr->attr.name);
382 	if (index < 0)
383 		return -EINVAL;
384 
385 	if (mutex_lock_interruptible(&ptp->pincfg_mux))
386 		return -ERESTARTSYS;
387 
388 	func = ptp->info->pin_config[index].func;
389 	chan = ptp->info->pin_config[index].chan;
390 
391 	mutex_unlock(&ptp->pincfg_mux);
392 
393 	return sysfs_emit(page, "%u %u\n", func, chan);
394 }
395 
396 static ssize_t ptp_pin_store(struct device *dev, struct device_attribute *attr,
397 			     const char *buf, size_t count)
398 {
399 	struct ptp_clock *ptp = dev_get_drvdata(dev);
400 	unsigned int func, chan;
401 	int cnt, err, index;
402 
403 	cnt = sscanf(buf, "%u %u", &func, &chan);
404 	if (cnt != 2)
405 		return -EINVAL;
406 
407 	index = ptp_pin_name2index(ptp, attr->attr.name);
408 	if (index < 0)
409 		return -EINVAL;
410 
411 	if (mutex_lock_interruptible(&ptp->pincfg_mux))
412 		return -ERESTARTSYS;
413 	err = ptp_set_pinfunc(ptp, index, func, chan);
414 	mutex_unlock(&ptp->pincfg_mux);
415 	if (err)
416 		return err;
417 
418 	return count;
419 }
420 
421 int ptp_populate_pin_groups(struct ptp_clock *ptp)
422 {
423 	struct ptp_clock_info *info = ptp->info;
424 	int err = -ENOMEM, i, n_pins = info->n_pins;
425 
426 	if (!n_pins)
427 		return 0;
428 
429 	ptp->pin_dev_attr = kcalloc(n_pins, sizeof(*ptp->pin_dev_attr),
430 				    GFP_KERNEL);
431 	if (!ptp->pin_dev_attr)
432 		goto no_dev_attr;
433 
434 	ptp->pin_attr = kcalloc(1 + n_pins, sizeof(*ptp->pin_attr), GFP_KERNEL);
435 	if (!ptp->pin_attr)
436 		goto no_pin_attr;
437 
438 	for (i = 0; i < n_pins; i++) {
439 		struct device_attribute *da = &ptp->pin_dev_attr[i];
440 		sysfs_attr_init(&da->attr);
441 		da->attr.name = info->pin_config[i].name;
442 		da->attr.mode = 0644;
443 		da->show = ptp_pin_show;
444 		da->store = ptp_pin_store;
445 		ptp->pin_attr[i] = &da->attr;
446 	}
447 
448 	ptp->pin_attr_group.name = "pins";
449 	ptp->pin_attr_group.attrs = ptp->pin_attr;
450 
451 	ptp->pin_attr_groups[0] = &ptp->pin_attr_group;
452 
453 	return 0;
454 
455 no_pin_attr:
456 	kfree(ptp->pin_dev_attr);
457 no_dev_attr:
458 	return err;
459 }
460 
461 void ptp_cleanup_pin_groups(struct ptp_clock *ptp)
462 {
463 	kfree(ptp->pin_attr);
464 	kfree(ptp->pin_dev_attr);
465 }
466