xref: /openbmc/linux/drivers/ptp/ptp_sysfs.c (revision cd5d5810)
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 
22 #include "ptp_private.h"
23 
24 static ssize_t clock_name_show(struct device *dev,
25 			       struct device_attribute *attr, char *page)
26 {
27 	struct ptp_clock *ptp = dev_get_drvdata(dev);
28 	return snprintf(page, PAGE_SIZE-1, "%s\n", ptp->info->name);
29 }
30 static DEVICE_ATTR(clock_name, 0444, clock_name_show, NULL);
31 
32 #define PTP_SHOW_INT(name, var)						\
33 static ssize_t var##_show(struct device *dev,				\
34 			   struct device_attribute *attr, char *page)	\
35 {									\
36 	struct ptp_clock *ptp = dev_get_drvdata(dev);			\
37 	return snprintf(page, PAGE_SIZE-1, "%d\n", ptp->info->var);	\
38 }									\
39 static DEVICE_ATTR(name, 0444, var##_show, NULL);
40 
41 PTP_SHOW_INT(max_adjustment, max_adj);
42 PTP_SHOW_INT(n_alarms, n_alarm);
43 PTP_SHOW_INT(n_external_timestamps, n_ext_ts);
44 PTP_SHOW_INT(n_periodic_outputs, n_per_out);
45 PTP_SHOW_INT(pps_available, pps);
46 
47 static struct attribute *ptp_attrs[] = {
48 	&dev_attr_clock_name.attr,
49 	&dev_attr_max_adjustment.attr,
50 	&dev_attr_n_alarms.attr,
51 	&dev_attr_n_external_timestamps.attr,
52 	&dev_attr_n_periodic_outputs.attr,
53 	&dev_attr_pps_available.attr,
54 	NULL,
55 };
56 
57 static const struct attribute_group ptp_group = {
58 	.attrs = ptp_attrs,
59 };
60 
61 const struct attribute_group *ptp_groups[] = {
62 	&ptp_group,
63 	NULL,
64 };
65 
66 
67 static ssize_t extts_enable_store(struct device *dev,
68 				  struct device_attribute *attr,
69 				  const char *buf, size_t count)
70 {
71 	struct ptp_clock *ptp = dev_get_drvdata(dev);
72 	struct ptp_clock_info *ops = ptp->info;
73 	struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
74 	int cnt, enable;
75 	int err = -EINVAL;
76 
77 	cnt = sscanf(buf, "%u %d", &req.extts.index, &enable);
78 	if (cnt != 2)
79 		goto out;
80 	if (req.extts.index >= ops->n_ext_ts)
81 		goto out;
82 
83 	err = ops->enable(ops, &req, enable ? 1 : 0);
84 	if (err)
85 		goto out;
86 
87 	return count;
88 out:
89 	return err;
90 }
91 
92 static ssize_t extts_fifo_show(struct device *dev,
93 			       struct device_attribute *attr, char *page)
94 {
95 	struct ptp_clock *ptp = dev_get_drvdata(dev);
96 	struct timestamp_event_queue *queue = &ptp->tsevq;
97 	struct ptp_extts_event event;
98 	unsigned long flags;
99 	size_t qcnt;
100 	int cnt = 0;
101 
102 	memset(&event, 0, sizeof(event));
103 
104 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
105 		return -ERESTARTSYS;
106 
107 	spin_lock_irqsave(&queue->lock, flags);
108 	qcnt = queue_cnt(queue);
109 	if (qcnt) {
110 		event = queue->buf[queue->head];
111 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
112 	}
113 	spin_unlock_irqrestore(&queue->lock, flags);
114 
115 	if (!qcnt)
116 		goto out;
117 
118 	cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
119 		       event.index, event.t.sec, event.t.nsec);
120 out:
121 	mutex_unlock(&ptp->tsevq_mux);
122 	return cnt;
123 }
124 
125 static ssize_t period_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_PEROUT };
132 	int cnt, enable, err = -EINVAL;
133 
134 	cnt = sscanf(buf, "%u %lld %u %lld %u", &req.perout.index,
135 		     &req.perout.start.sec, &req.perout.start.nsec,
136 		     &req.perout.period.sec, &req.perout.period.nsec);
137 	if (cnt != 5)
138 		goto out;
139 	if (req.perout.index >= ops->n_per_out)
140 		goto out;
141 
142 	enable = req.perout.period.sec || req.perout.period.nsec;
143 	err = ops->enable(ops, &req, enable);
144 	if (err)
145 		goto out;
146 
147 	return count;
148 out:
149 	return err;
150 }
151 
152 static ssize_t pps_enable_store(struct device *dev,
153 				struct device_attribute *attr,
154 				const char *buf, size_t count)
155 {
156 	struct ptp_clock *ptp = dev_get_drvdata(dev);
157 	struct ptp_clock_info *ops = ptp->info;
158 	struct ptp_clock_request req = { .type = PTP_CLK_REQ_PPS };
159 	int cnt, enable;
160 	int err = -EINVAL;
161 
162 	if (!capable(CAP_SYS_TIME))
163 		return -EPERM;
164 
165 	cnt = sscanf(buf, "%d", &enable);
166 	if (cnt != 1)
167 		goto out;
168 
169 	err = ops->enable(ops, &req, enable ? 1 : 0);
170 	if (err)
171 		goto out;
172 
173 	return count;
174 out:
175 	return err;
176 }
177 
178 static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
179 static DEVICE_ATTR(fifo,         0444, extts_fifo_show, NULL);
180 static DEVICE_ATTR(period,       0220, NULL, period_store);
181 static DEVICE_ATTR(pps_enable,   0220, NULL, pps_enable_store);
182 
183 int ptp_cleanup_sysfs(struct ptp_clock *ptp)
184 {
185 	struct device *dev = ptp->dev;
186 	struct ptp_clock_info *info = ptp->info;
187 
188 	if (info->n_ext_ts) {
189 		device_remove_file(dev, &dev_attr_extts_enable);
190 		device_remove_file(dev, &dev_attr_fifo);
191 	}
192 	if (info->n_per_out)
193 		device_remove_file(dev, &dev_attr_period);
194 
195 	if (info->pps)
196 		device_remove_file(dev, &dev_attr_pps_enable);
197 
198 	return 0;
199 }
200 
201 int ptp_populate_sysfs(struct ptp_clock *ptp)
202 {
203 	struct device *dev = ptp->dev;
204 	struct ptp_clock_info *info = ptp->info;
205 	int err;
206 
207 	if (info->n_ext_ts) {
208 		err = device_create_file(dev, &dev_attr_extts_enable);
209 		if (err)
210 			goto out1;
211 		err = device_create_file(dev, &dev_attr_fifo);
212 		if (err)
213 			goto out2;
214 	}
215 	if (info->n_per_out) {
216 		err = device_create_file(dev, &dev_attr_period);
217 		if (err)
218 			goto out3;
219 	}
220 	if (info->pps) {
221 		err = device_create_file(dev, &dev_attr_pps_enable);
222 		if (err)
223 			goto out4;
224 	}
225 	return 0;
226 out4:
227 	if (info->n_per_out)
228 		device_remove_file(dev, &dev_attr_period);
229 out3:
230 	if (info->n_ext_ts)
231 		device_remove_file(dev, &dev_attr_fifo);
232 out2:
233 	if (info->n_ext_ts)
234 		device_remove_file(dev, &dev_attr_extts_enable);
235 out1:
236 	return err;
237 }
238