xref: /openbmc/linux/drivers/ptp/ptp_sysfs.c (revision 63dc02bd)
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 
31 #define PTP_SHOW_INT(name)						\
32 static ssize_t name##_show(struct device *dev,				\
33 			   struct device_attribute *attr, char *page)	\
34 {									\
35 	struct ptp_clock *ptp = dev_get_drvdata(dev);			\
36 	return snprintf(page, PAGE_SIZE-1, "%d\n", ptp->info->name);	\
37 }
38 
39 PTP_SHOW_INT(max_adj);
40 PTP_SHOW_INT(n_alarm);
41 PTP_SHOW_INT(n_ext_ts);
42 PTP_SHOW_INT(n_per_out);
43 PTP_SHOW_INT(pps);
44 
45 #define PTP_RO_ATTR(_var, _name) {				\
46 	.attr	= { .name = __stringify(_name), .mode = 0444 },	\
47 	.show	= _var##_show,					\
48 }
49 
50 struct device_attribute ptp_dev_attrs[] = {
51 	PTP_RO_ATTR(clock_name,	clock_name),
52 	PTP_RO_ATTR(max_adj,	max_adjustment),
53 	PTP_RO_ATTR(n_alarm,	n_alarms),
54 	PTP_RO_ATTR(n_ext_ts,	n_external_timestamps),
55 	PTP_RO_ATTR(n_per_out,	n_periodic_outputs),
56 	PTP_RO_ATTR(pps,	pps_available),
57 	__ATTR_NULL,
58 };
59 
60 static ssize_t extts_enable_store(struct device *dev,
61 				  struct device_attribute *attr,
62 				  const char *buf, size_t count)
63 {
64 	struct ptp_clock *ptp = dev_get_drvdata(dev);
65 	struct ptp_clock_info *ops = ptp->info;
66 	struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
67 	int cnt, enable;
68 	int err = -EINVAL;
69 
70 	cnt = sscanf(buf, "%u %d", &req.extts.index, &enable);
71 	if (cnt != 2)
72 		goto out;
73 	if (req.extts.index >= ops->n_ext_ts)
74 		goto out;
75 
76 	err = ops->enable(ops, &req, enable ? 1 : 0);
77 	if (err)
78 		goto out;
79 
80 	return count;
81 out:
82 	return err;
83 }
84 
85 static ssize_t extts_fifo_show(struct device *dev,
86 			       struct device_attribute *attr, char *page)
87 {
88 	struct ptp_clock *ptp = dev_get_drvdata(dev);
89 	struct timestamp_event_queue *queue = &ptp->tsevq;
90 	struct ptp_extts_event event;
91 	unsigned long flags;
92 	size_t qcnt;
93 	int cnt = 0;
94 
95 	memset(&event, 0, sizeof(event));
96 
97 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
98 		return -ERESTARTSYS;
99 
100 	spin_lock_irqsave(&queue->lock, flags);
101 	qcnt = queue_cnt(queue);
102 	if (qcnt) {
103 		event = queue->buf[queue->head];
104 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
105 	}
106 	spin_unlock_irqrestore(&queue->lock, flags);
107 
108 	if (!qcnt)
109 		goto out;
110 
111 	cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
112 		       event.index, event.t.sec, event.t.nsec);
113 out:
114 	mutex_unlock(&ptp->tsevq_mux);
115 	return cnt;
116 }
117 
118 static ssize_t period_store(struct device *dev,
119 			    struct device_attribute *attr,
120 			    const char *buf, size_t count)
121 {
122 	struct ptp_clock *ptp = dev_get_drvdata(dev);
123 	struct ptp_clock_info *ops = ptp->info;
124 	struct ptp_clock_request req = { .type = PTP_CLK_REQ_PEROUT };
125 	int cnt, enable, err = -EINVAL;
126 
127 	cnt = sscanf(buf, "%u %lld %u %lld %u", &req.perout.index,
128 		     &req.perout.start.sec, &req.perout.start.nsec,
129 		     &req.perout.period.sec, &req.perout.period.nsec);
130 	if (cnt != 5)
131 		goto out;
132 	if (req.perout.index >= ops->n_per_out)
133 		goto out;
134 
135 	enable = req.perout.period.sec || req.perout.period.nsec;
136 	err = ops->enable(ops, &req, enable);
137 	if (err)
138 		goto out;
139 
140 	return count;
141 out:
142 	return err;
143 }
144 
145 static ssize_t pps_enable_store(struct device *dev,
146 				struct device_attribute *attr,
147 				const char *buf, size_t count)
148 {
149 	struct ptp_clock *ptp = dev_get_drvdata(dev);
150 	struct ptp_clock_info *ops = ptp->info;
151 	struct ptp_clock_request req = { .type = PTP_CLK_REQ_PPS };
152 	int cnt, enable;
153 	int err = -EINVAL;
154 
155 	if (!capable(CAP_SYS_TIME))
156 		return -EPERM;
157 
158 	cnt = sscanf(buf, "%d", &enable);
159 	if (cnt != 1)
160 		goto out;
161 
162 	err = ops->enable(ops, &req, enable ? 1 : 0);
163 	if (err)
164 		goto out;
165 
166 	return count;
167 out:
168 	return err;
169 }
170 
171 static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
172 static DEVICE_ATTR(fifo,         0444, extts_fifo_show, NULL);
173 static DEVICE_ATTR(period,       0220, NULL, period_store);
174 static DEVICE_ATTR(pps_enable,   0220, NULL, pps_enable_store);
175 
176 int ptp_cleanup_sysfs(struct ptp_clock *ptp)
177 {
178 	struct device *dev = ptp->dev;
179 	struct ptp_clock_info *info = ptp->info;
180 
181 	if (info->n_ext_ts) {
182 		device_remove_file(dev, &dev_attr_extts_enable);
183 		device_remove_file(dev, &dev_attr_fifo);
184 	}
185 	if (info->n_per_out)
186 		device_remove_file(dev, &dev_attr_period);
187 
188 	if (info->pps)
189 		device_remove_file(dev, &dev_attr_pps_enable);
190 
191 	return 0;
192 }
193 
194 int ptp_populate_sysfs(struct ptp_clock *ptp)
195 {
196 	struct device *dev = ptp->dev;
197 	struct ptp_clock_info *info = ptp->info;
198 	int err;
199 
200 	if (info->n_ext_ts) {
201 		err = device_create_file(dev, &dev_attr_extts_enable);
202 		if (err)
203 			goto out1;
204 		err = device_create_file(dev, &dev_attr_fifo);
205 		if (err)
206 			goto out2;
207 	}
208 	if (info->n_per_out) {
209 		err = device_create_file(dev, &dev_attr_period);
210 		if (err)
211 			goto out3;
212 	}
213 	if (info->pps) {
214 		err = device_create_file(dev, &dev_attr_pps_enable);
215 		if (err)
216 			goto out4;
217 	}
218 	return 0;
219 out4:
220 	if (info->n_per_out)
221 		device_remove_file(dev, &dev_attr_period);
222 out3:
223 	if (info->n_ext_ts)
224 		device_remove_file(dev, &dev_attr_fifo);
225 out2:
226 	if (info->n_ext_ts)
227 		device_remove_file(dev, &dev_attr_extts_enable);
228 out1:
229 	return err;
230 }
231