xref: /openbmc/linux/drivers/ptp/ptp_sysfs.c (revision 4f6cce39)
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_RO(clock_name);
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 ssize_t extts_enable_store(struct device *dev,
50 				  struct device_attribute *attr,
51 				  const char *buf, size_t count)
52 {
53 	struct ptp_clock *ptp = dev_get_drvdata(dev);
54 	struct ptp_clock_info *ops = ptp->info;
55 	struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
56 	int cnt, enable;
57 	int err = -EINVAL;
58 
59 	cnt = sscanf(buf, "%u %d", &req.extts.index, &enable);
60 	if (cnt != 2)
61 		goto out;
62 	if (req.extts.index >= ops->n_ext_ts)
63 		goto out;
64 
65 	err = ops->enable(ops, &req, enable ? 1 : 0);
66 	if (err)
67 		goto out;
68 
69 	return count;
70 out:
71 	return err;
72 }
73 static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
74 
75 static ssize_t extts_fifo_show(struct device *dev,
76 			       struct device_attribute *attr, char *page)
77 {
78 	struct ptp_clock *ptp = dev_get_drvdata(dev);
79 	struct timestamp_event_queue *queue = &ptp->tsevq;
80 	struct ptp_extts_event event;
81 	unsigned long flags;
82 	size_t qcnt;
83 	int cnt = 0;
84 
85 	memset(&event, 0, sizeof(event));
86 
87 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
88 		return -ERESTARTSYS;
89 
90 	spin_lock_irqsave(&queue->lock, flags);
91 	qcnt = queue_cnt(queue);
92 	if (qcnt) {
93 		event = queue->buf[queue->head];
94 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
95 	}
96 	spin_unlock_irqrestore(&queue->lock, flags);
97 
98 	if (!qcnt)
99 		goto out;
100 
101 	cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
102 		       event.index, event.t.sec, event.t.nsec);
103 out:
104 	mutex_unlock(&ptp->tsevq_mux);
105 	return cnt;
106 }
107 static DEVICE_ATTR(fifo, 0444, extts_fifo_show, NULL);
108 
109 static ssize_t period_store(struct device *dev,
110 			    struct device_attribute *attr,
111 			    const char *buf, size_t count)
112 {
113 	struct ptp_clock *ptp = dev_get_drvdata(dev);
114 	struct ptp_clock_info *ops = ptp->info;
115 	struct ptp_clock_request req = { .type = PTP_CLK_REQ_PEROUT };
116 	int cnt, enable, err = -EINVAL;
117 
118 	cnt = sscanf(buf, "%u %lld %u %lld %u", &req.perout.index,
119 		     &req.perout.start.sec, &req.perout.start.nsec,
120 		     &req.perout.period.sec, &req.perout.period.nsec);
121 	if (cnt != 5)
122 		goto out;
123 	if (req.perout.index >= ops->n_per_out)
124 		goto out;
125 
126 	enable = req.perout.period.sec || req.perout.period.nsec;
127 	err = ops->enable(ops, &req, enable);
128 	if (err)
129 		goto out;
130 
131 	return count;
132 out:
133 	return err;
134 }
135 static DEVICE_ATTR(period, 0220, NULL, period_store);
136 
137 static ssize_t pps_enable_store(struct device *dev,
138 				struct device_attribute *attr,
139 				const char *buf, size_t count)
140 {
141 	struct ptp_clock *ptp = dev_get_drvdata(dev);
142 	struct ptp_clock_info *ops = ptp->info;
143 	struct ptp_clock_request req = { .type = PTP_CLK_REQ_PPS };
144 	int cnt, enable;
145 	int err = -EINVAL;
146 
147 	if (!capable(CAP_SYS_TIME))
148 		return -EPERM;
149 
150 	cnt = sscanf(buf, "%d", &enable);
151 	if (cnt != 1)
152 		goto out;
153 
154 	err = ops->enable(ops, &req, enable ? 1 : 0);
155 	if (err)
156 		goto out;
157 
158 	return count;
159 out:
160 	return err;
161 }
162 static DEVICE_ATTR(pps_enable, 0220, NULL, pps_enable_store);
163 
164 static struct attribute *ptp_attrs[] = {
165 	&dev_attr_clock_name.attr,
166 
167 	&dev_attr_max_adjustment.attr,
168 	&dev_attr_n_alarms.attr,
169 	&dev_attr_n_external_timestamps.attr,
170 	&dev_attr_n_periodic_outputs.attr,
171 	&dev_attr_n_programmable_pins.attr,
172 	&dev_attr_pps_available.attr,
173 
174 	&dev_attr_extts_enable.attr,
175 	&dev_attr_fifo.attr,
176 	&dev_attr_period.attr,
177 	&dev_attr_pps_enable.attr,
178 	NULL
179 };
180 
181 static umode_t ptp_is_attribute_visible(struct kobject *kobj,
182 					struct attribute *attr, int n)
183 {
184 	struct device *dev = kobj_to_dev(kobj);
185 	struct ptp_clock *ptp = dev_get_drvdata(dev);
186 	struct ptp_clock_info *info = ptp->info;
187 	umode_t mode = attr->mode;
188 
189 	if (attr == &dev_attr_extts_enable.attr ||
190 	    attr == &dev_attr_fifo.attr) {
191 		if (!info->n_ext_ts)
192 			mode = 0;
193 	} else if (attr == &dev_attr_period.attr) {
194 		if (!info->n_per_out)
195 			mode = 0;
196 	} else if (attr == &dev_attr_pps_enable.attr) {
197 		if (!info->pps)
198 			mode = 0;
199 	}
200 
201 	return mode;
202 }
203 
204 static const struct attribute_group ptp_group = {
205 	.is_visible	= ptp_is_attribute_visible,
206 	.attrs		= ptp_attrs,
207 };
208 
209 const struct attribute_group *ptp_groups[] = {
210 	&ptp_group,
211 	NULL
212 };
213 
214 static int ptp_pin_name2index(struct ptp_clock *ptp, const char *name)
215 {
216 	int i;
217 	for (i = 0; i < ptp->info->n_pins; i++) {
218 		if (!strcmp(ptp->info->pin_config[i].name, name))
219 			return i;
220 	}
221 	return -1;
222 }
223 
224 static ssize_t ptp_pin_show(struct device *dev, struct device_attribute *attr,
225 			    char *page)
226 {
227 	struct ptp_clock *ptp = dev_get_drvdata(dev);
228 	unsigned int func, chan;
229 	int index;
230 
231 	index = ptp_pin_name2index(ptp, attr->attr.name);
232 	if (index < 0)
233 		return -EINVAL;
234 
235 	if (mutex_lock_interruptible(&ptp->pincfg_mux))
236 		return -ERESTARTSYS;
237 
238 	func = ptp->info->pin_config[index].func;
239 	chan = ptp->info->pin_config[index].chan;
240 
241 	mutex_unlock(&ptp->pincfg_mux);
242 
243 	return snprintf(page, PAGE_SIZE, "%u %u\n", func, chan);
244 }
245 
246 static ssize_t ptp_pin_store(struct device *dev, struct device_attribute *attr,
247 			     const char *buf, size_t count)
248 {
249 	struct ptp_clock *ptp = dev_get_drvdata(dev);
250 	unsigned int func, chan;
251 	int cnt, err, index;
252 
253 	cnt = sscanf(buf, "%u %u", &func, &chan);
254 	if (cnt != 2)
255 		return -EINVAL;
256 
257 	index = ptp_pin_name2index(ptp, attr->attr.name);
258 	if (index < 0)
259 		return -EINVAL;
260 
261 	if (mutex_lock_interruptible(&ptp->pincfg_mux))
262 		return -ERESTARTSYS;
263 	err = ptp_set_pinfunc(ptp, index, func, chan);
264 	mutex_unlock(&ptp->pincfg_mux);
265 	if (err)
266 		return err;
267 
268 	return count;
269 }
270 
271 int ptp_populate_pin_groups(struct ptp_clock *ptp)
272 {
273 	struct ptp_clock_info *info = ptp->info;
274 	int err = -ENOMEM, i, n_pins = info->n_pins;
275 
276 	if (!n_pins)
277 		return 0;
278 
279 	ptp->pin_dev_attr = kcalloc(n_pins, sizeof(*ptp->pin_dev_attr),
280 				    GFP_KERNEL);
281 	if (!ptp->pin_dev_attr)
282 		goto no_dev_attr;
283 
284 	ptp->pin_attr = kcalloc(1 + n_pins, sizeof(*ptp->pin_attr), GFP_KERNEL);
285 	if (!ptp->pin_attr)
286 		goto no_pin_attr;
287 
288 	for (i = 0; i < n_pins; i++) {
289 		struct device_attribute *da = &ptp->pin_dev_attr[i];
290 		sysfs_attr_init(&da->attr);
291 		da->attr.name = info->pin_config[i].name;
292 		da->attr.mode = 0644;
293 		da->show = ptp_pin_show;
294 		da->store = ptp_pin_store;
295 		ptp->pin_attr[i] = &da->attr;
296 	}
297 
298 	ptp->pin_attr_group.name = "pins";
299 	ptp->pin_attr_group.attrs = ptp->pin_attr;
300 
301 	ptp->pin_attr_groups[0] = &ptp->pin_attr_group;
302 
303 	return 0;
304 
305 no_pin_attr:
306 	kfree(ptp->pin_dev_attr);
307 no_dev_attr:
308 	return err;
309 }
310 
311 void ptp_cleanup_pin_groups(struct ptp_clock *ptp)
312 {
313 	kfree(ptp->pin_attr);
314 	kfree(ptp->pin_dev_attr);
315 }
316