1 /*
2 * TI Common Platform Time Sync
3 *
4 * Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20 #include <linux/err.h>
21 #include <linux/if.h>
22 #include <linux/hrtimer.h>
23 #include <linux/module.h>
24 #include <linux/net_tstamp.h>
25 #include <linux/ptp_classify.h>
26 #include <linux/time.h>
27 #include <linux/uaccess.h>
28 #include <linux/workqueue.h>
29 #include <linux/if_ether.h>
30 #include <linux/if_vlan.h>
31
32 #include "cpts.h"
33
34 #ifdef CONFIG_TI_CPTS
35
36 #define cpts_read32(c, r) __raw_readl(&c->reg->r)
37 #define cpts_write32(c, v, r) __raw_writel(v, &c->reg->r)
38
event_expired(struct cpts_event * event)39 static int event_expired(struct cpts_event *event)
40 {
41 return time_after(jiffies, event->tmo);
42 }
43
event_type(struct cpts_event * event)44 static int event_type(struct cpts_event *event)
45 {
46 return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK;
47 }
48
cpts_fifo_pop(struct cpts * cpts,u32 * high,u32 * low)49 static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low)
50 {
51 u32 r = cpts_read32(cpts, intstat_raw);
52
53 if (r & TS_PEND_RAW) {
54 *high = cpts_read32(cpts, event_high);
55 *low = cpts_read32(cpts, event_low);
56 cpts_write32(cpts, EVENT_POP, event_pop);
57 return 0;
58 }
59 return -1;
60 }
61
62 /*
63 * Returns zero if matching event type was found.
64 */
cpts_fifo_read(struct cpts * cpts,int match)65 static int cpts_fifo_read(struct cpts *cpts, int match)
66 {
67 int i, type = -1;
68 u32 hi, lo;
69 struct cpts_event *event;
70
71 for (i = 0; i < CPTS_FIFO_DEPTH; i++) {
72 if (cpts_fifo_pop(cpts, &hi, &lo))
73 break;
74 if (list_empty(&cpts->pool)) {
75 pr_err("cpts: event pool is empty\n");
76 return -1;
77 }
78 event = list_first_entry(&cpts->pool, struct cpts_event, list);
79 event->tmo = jiffies + 2;
80 event->high = hi;
81 event->low = lo;
82 type = event_type(event);
83 switch (type) {
84 case CPTS_EV_PUSH:
85 case CPTS_EV_RX:
86 case CPTS_EV_TX:
87 list_del_init(&event->list);
88 list_add_tail(&event->list, &cpts->events);
89 break;
90 case CPTS_EV_ROLL:
91 case CPTS_EV_HALF:
92 case CPTS_EV_HW:
93 break;
94 default:
95 pr_err("cpts: unknown event type\n");
96 break;
97 }
98 if (type == match)
99 break;
100 }
101 return type == match ? 0 : -1;
102 }
103
cpts_systim_read(const struct cyclecounter * cc)104 static cycle_t cpts_systim_read(const struct cyclecounter *cc)
105 {
106 u64 val = 0;
107 struct cpts_event *event;
108 struct list_head *this, *next;
109 struct cpts *cpts = container_of(cc, struct cpts, cc);
110
111 cpts_write32(cpts, TS_PUSH, ts_push);
112 if (cpts_fifo_read(cpts, CPTS_EV_PUSH))
113 pr_err("cpts: unable to obtain a time stamp\n");
114
115 list_for_each_safe(this, next, &cpts->events) {
116 event = list_entry(this, struct cpts_event, list);
117 if (event_type(event) == CPTS_EV_PUSH) {
118 list_del_init(&event->list);
119 list_add(&event->list, &cpts->pool);
120 val = event->low;
121 break;
122 }
123 }
124
125 return val;
126 }
127
128 /* PTP clock operations */
129
cpts_ptp_adjfreq(struct ptp_clock_info * ptp,s32 ppb)130 static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
131 {
132 u64 adj;
133 u32 diff, mult;
134 int neg_adj = 0;
135 unsigned long flags;
136 struct cpts *cpts = container_of(ptp, struct cpts, info);
137
138 if (ppb < 0) {
139 neg_adj = 1;
140 ppb = -ppb;
141 }
142 mult = cpts->cc_mult;
143 adj = mult;
144 adj *= ppb;
145 diff = div_u64(adj, 1000000000ULL);
146
147 spin_lock_irqsave(&cpts->lock, flags);
148
149 timecounter_read(&cpts->tc);
150
151 cpts->cc.mult = neg_adj ? mult - diff : mult + diff;
152
153 spin_unlock_irqrestore(&cpts->lock, flags);
154
155 return 0;
156 }
157
cpts_ptp_adjtime(struct ptp_clock_info * ptp,s64 delta)158 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
159 {
160 s64 now;
161 unsigned long flags;
162 struct cpts *cpts = container_of(ptp, struct cpts, info);
163
164 spin_lock_irqsave(&cpts->lock, flags);
165 now = timecounter_read(&cpts->tc);
166 now += delta;
167 timecounter_init(&cpts->tc, &cpts->cc, now);
168 spin_unlock_irqrestore(&cpts->lock, flags);
169
170 return 0;
171 }
172
cpts_ptp_gettime(struct ptp_clock_info * ptp,struct timespec * ts)173 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
174 {
175 u64 ns;
176 u32 remainder;
177 unsigned long flags;
178 struct cpts *cpts = container_of(ptp, struct cpts, info);
179
180 spin_lock_irqsave(&cpts->lock, flags);
181 ns = timecounter_read(&cpts->tc);
182 spin_unlock_irqrestore(&cpts->lock, flags);
183
184 ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
185 ts->tv_nsec = remainder;
186
187 return 0;
188 }
189
cpts_ptp_settime(struct ptp_clock_info * ptp,const struct timespec * ts)190 static int cpts_ptp_settime(struct ptp_clock_info *ptp,
191 const struct timespec *ts)
192 {
193 u64 ns;
194 unsigned long flags;
195 struct cpts *cpts = container_of(ptp, struct cpts, info);
196
197 ns = ts->tv_sec * 1000000000ULL;
198 ns += ts->tv_nsec;
199
200 spin_lock_irqsave(&cpts->lock, flags);
201 timecounter_init(&cpts->tc, &cpts->cc, ns);
202 spin_unlock_irqrestore(&cpts->lock, flags);
203
204 return 0;
205 }
206
cpts_ptp_enable(struct ptp_clock_info * ptp,struct ptp_clock_request * rq,int on)207 static int cpts_ptp_enable(struct ptp_clock_info *ptp,
208 struct ptp_clock_request *rq, int on)
209 {
210 return -EOPNOTSUPP;
211 }
212
213 static struct ptp_clock_info cpts_info = {
214 .owner = THIS_MODULE,
215 .name = "CTPS timer",
216 .max_adj = 1000000,
217 .n_ext_ts = 0,
218 .n_pins = 0,
219 .pps = 0,
220 .adjfreq = cpts_ptp_adjfreq,
221 .adjtime = cpts_ptp_adjtime,
222 .gettime = cpts_ptp_gettime,
223 .settime = cpts_ptp_settime,
224 .enable = cpts_ptp_enable,
225 };
226
cpts_overflow_check(struct work_struct * work)227 static void cpts_overflow_check(struct work_struct *work)
228 {
229 struct timespec ts;
230 struct cpts *cpts = container_of(work, struct cpts, overflow_work.work);
231
232 cpts_write32(cpts, CPTS_EN, control);
233 cpts_write32(cpts, TS_PEND_EN, int_enable);
234 cpts_ptp_gettime(&cpts->info, &ts);
235 pr_debug("cpts overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec);
236 schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
237 }
238
cpts_clk_init(struct device * dev,struct cpts * cpts)239 static void cpts_clk_init(struct device *dev, struct cpts *cpts)
240 {
241 cpts->refclk = devm_clk_get(dev, "cpts");
242 if (IS_ERR(cpts->refclk)) {
243 dev_err(dev, "Failed to get cpts refclk\n");
244 cpts->refclk = NULL;
245 return;
246 }
247 clk_prepare_enable(cpts->refclk);
248 }
249
cpts_clk_release(struct cpts * cpts)250 static void cpts_clk_release(struct cpts *cpts)
251 {
252 clk_disable(cpts->refclk);
253 }
254
cpts_match(struct sk_buff * skb,unsigned int ptp_class,u16 ts_seqid,u8 ts_msgtype)255 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
256 u16 ts_seqid, u8 ts_msgtype)
257 {
258 u16 *seqid;
259 unsigned int offset = 0;
260 u8 *msgtype, *data = skb->data;
261
262 if (ptp_class & PTP_CLASS_VLAN)
263 offset += VLAN_HLEN;
264
265 switch (ptp_class & PTP_CLASS_PMASK) {
266 case PTP_CLASS_IPV4:
267 offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN;
268 break;
269 case PTP_CLASS_IPV6:
270 offset += ETH_HLEN + IP6_HLEN + UDP_HLEN;
271 break;
272 case PTP_CLASS_L2:
273 offset += ETH_HLEN;
274 break;
275 default:
276 return 0;
277 }
278
279 if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid))
280 return 0;
281
282 if (unlikely(ptp_class & PTP_CLASS_V1))
283 msgtype = data + offset + OFF_PTP_CONTROL;
284 else
285 msgtype = data + offset;
286
287 seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID);
288
289 return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid));
290 }
291
cpts_find_ts(struct cpts * cpts,struct sk_buff * skb,int ev_type)292 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type)
293 {
294 u64 ns = 0;
295 struct cpts_event *event;
296 struct list_head *this, *next;
297 unsigned int class = ptp_classify_raw(skb);
298 unsigned long flags;
299 u16 seqid;
300 u8 mtype;
301
302 if (class == PTP_CLASS_NONE)
303 return 0;
304
305 spin_lock_irqsave(&cpts->lock, flags);
306 cpts_fifo_read(cpts, CPTS_EV_PUSH);
307 list_for_each_safe(this, next, &cpts->events) {
308 event = list_entry(this, struct cpts_event, list);
309 if (event_expired(event)) {
310 list_del_init(&event->list);
311 list_add(&event->list, &cpts->pool);
312 continue;
313 }
314 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
315 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;
316 if (ev_type == event_type(event) &&
317 cpts_match(skb, class, seqid, mtype)) {
318 ns = timecounter_cyc2time(&cpts->tc, event->low);
319 list_del_init(&event->list);
320 list_add(&event->list, &cpts->pool);
321 break;
322 }
323 }
324 spin_unlock_irqrestore(&cpts->lock, flags);
325
326 return ns;
327 }
328
cpts_rx_timestamp(struct cpts * cpts,struct sk_buff * skb)329 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
330 {
331 u64 ns;
332 struct skb_shared_hwtstamps *ssh;
333
334 if (!cpts->rx_enable)
335 return;
336 ns = cpts_find_ts(cpts, skb, CPTS_EV_RX);
337 if (!ns)
338 return;
339 ssh = skb_hwtstamps(skb);
340 memset(ssh, 0, sizeof(*ssh));
341 ssh->hwtstamp = ns_to_ktime(ns);
342 }
343
cpts_tx_timestamp(struct cpts * cpts,struct sk_buff * skb)344 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
345 {
346 u64 ns;
347 struct skb_shared_hwtstamps ssh;
348
349 if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
350 return;
351 ns = cpts_find_ts(cpts, skb, CPTS_EV_TX);
352 if (!ns)
353 return;
354 memset(&ssh, 0, sizeof(ssh));
355 ssh.hwtstamp = ns_to_ktime(ns);
356 skb_tstamp_tx(skb, &ssh);
357 }
358
359 #endif /*CONFIG_TI_CPTS*/
360
cpts_register(struct device * dev,struct cpts * cpts,u32 mult,u32 shift)361 int cpts_register(struct device *dev, struct cpts *cpts,
362 u32 mult, u32 shift)
363 {
364 #ifdef CONFIG_TI_CPTS
365 int err, i;
366 unsigned long flags;
367
368 cpts->info = cpts_info;
369 cpts->clock = ptp_clock_register(&cpts->info, dev);
370 if (IS_ERR(cpts->clock)) {
371 err = PTR_ERR(cpts->clock);
372 cpts->clock = NULL;
373 return err;
374 }
375 spin_lock_init(&cpts->lock);
376
377 cpts->cc.read = cpts_systim_read;
378 cpts->cc.mask = CLOCKSOURCE_MASK(32);
379 cpts->cc_mult = mult;
380 cpts->cc.mult = mult;
381 cpts->cc.shift = shift;
382
383 INIT_LIST_HEAD(&cpts->events);
384 INIT_LIST_HEAD(&cpts->pool);
385 for (i = 0; i < CPTS_MAX_EVENTS; i++)
386 list_add(&cpts->pool_data[i].list, &cpts->pool);
387
388 cpts_clk_init(dev, cpts);
389 cpts_write32(cpts, CPTS_EN, control);
390 cpts_write32(cpts, TS_PEND_EN, int_enable);
391
392 spin_lock_irqsave(&cpts->lock, flags);
393 timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real()));
394 spin_unlock_irqrestore(&cpts->lock, flags);
395
396 INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check);
397 schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
398
399 cpts->phc_index = ptp_clock_index(cpts->clock);
400 #endif
401 return 0;
402 }
403
cpts_unregister(struct cpts * cpts)404 void cpts_unregister(struct cpts *cpts)
405 {
406 #ifdef CONFIG_TI_CPTS
407 if (cpts->clock) {
408 ptp_clock_unregister(cpts->clock);
409 cancel_delayed_work_sync(&cpts->overflow_work);
410 }
411 if (cpts->refclk)
412 cpts_clk_release(cpts);
413 #endif
414 }
415