1 // SPDX-License-Identifier: GPL-2.0+
2 /* PTP 1588 clock using the Renesas Ethernet AVB
3 *
4 * Copyright (C) 2013-2015 Renesas Electronics Corporation
5 * Copyright (C) 2015 Renesas Solutions Corp.
6 * Copyright (C) 2015-2016 Cogent Embedded, Inc. <source@cogentembedded.com>
7 */
8
9 #include "ravb.h"
10
ravb_ptp_tcr_request(struct ravb_private * priv,u32 request)11 static int ravb_ptp_tcr_request(struct ravb_private *priv, u32 request)
12 {
13 struct net_device *ndev = priv->ndev;
14 int error;
15
16 error = ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
17 if (error)
18 return error;
19
20 ravb_modify(ndev, GCCR, request, request);
21 return ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
22 }
23
24 /* Caller must hold the lock */
ravb_ptp_time_read(struct ravb_private * priv,struct timespec64 * ts)25 static int ravb_ptp_time_read(struct ravb_private *priv, struct timespec64 *ts)
26 {
27 struct net_device *ndev = priv->ndev;
28 int error;
29
30 error = ravb_ptp_tcr_request(priv, GCCR_TCR_CAPTURE);
31 if (error)
32 return error;
33
34 ts->tv_nsec = ravb_read(ndev, GCT0);
35 ts->tv_sec = ravb_read(ndev, GCT1) |
36 ((s64)ravb_read(ndev, GCT2) << 32);
37
38 return 0;
39 }
40
41 /* Caller must hold the lock */
ravb_ptp_time_write(struct ravb_private * priv,const struct timespec64 * ts)42 static int ravb_ptp_time_write(struct ravb_private *priv,
43 const struct timespec64 *ts)
44 {
45 struct net_device *ndev = priv->ndev;
46 int error;
47 u32 gccr;
48
49 error = ravb_ptp_tcr_request(priv, GCCR_TCR_RESET);
50 if (error)
51 return error;
52
53 gccr = ravb_read(ndev, GCCR);
54 if (gccr & GCCR_LTO)
55 return -EBUSY;
56 ravb_write(ndev, ts->tv_nsec, GTO0);
57 ravb_write(ndev, ts->tv_sec, GTO1);
58 ravb_write(ndev, (ts->tv_sec >> 32) & 0xffff, GTO2);
59 ravb_write(ndev, gccr | GCCR_LTO, GCCR);
60
61 return 0;
62 }
63
64 /* Caller must hold the lock */
ravb_ptp_update_compare(struct ravb_private * priv,u32 ns)65 static int ravb_ptp_update_compare(struct ravb_private *priv, u32 ns)
66 {
67 struct net_device *ndev = priv->ndev;
68 /* When the comparison value (GPTC.PTCV) is in range of
69 * [x-1 to x+1] (x is the configured increment value in
70 * GTI.TIV), it may happen that a comparison match is
71 * not detected when the timer wraps around.
72 */
73 u32 gti_ns_plus_1 = (priv->ptp.current_addend >> 20) + 1;
74 u32 gccr;
75
76 if (ns < gti_ns_plus_1)
77 ns = gti_ns_plus_1;
78 else if (ns > 0 - gti_ns_plus_1)
79 ns = 0 - gti_ns_plus_1;
80
81 gccr = ravb_read(ndev, GCCR);
82 if (gccr & GCCR_LPTC)
83 return -EBUSY;
84 ravb_write(ndev, ns, GPTC);
85 ravb_write(ndev, gccr | GCCR_LPTC, GCCR);
86
87 return 0;
88 }
89
90 /* PTP clock operations */
ravb_ptp_adjfreq(struct ptp_clock_info * ptp,s32 ppb)91 static int ravb_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
92 {
93 struct ravb_private *priv = container_of(ptp, struct ravb_private,
94 ptp.info);
95 struct net_device *ndev = priv->ndev;
96 unsigned long flags;
97 u32 diff, addend;
98 bool neg_adj = false;
99 u32 gccr;
100
101 if (ppb < 0) {
102 neg_adj = true;
103 ppb = -ppb;
104 }
105 addend = priv->ptp.default_addend;
106 diff = div_u64((u64)addend * ppb, NSEC_PER_SEC);
107
108 addend = neg_adj ? addend - diff : addend + diff;
109
110 spin_lock_irqsave(&priv->lock, flags);
111
112 priv->ptp.current_addend = addend;
113
114 gccr = ravb_read(ndev, GCCR);
115 if (gccr & GCCR_LTI) {
116 spin_unlock_irqrestore(&priv->lock, flags);
117 return -EBUSY;
118 }
119 ravb_write(ndev, addend & GTI_TIV, GTI);
120 ravb_write(ndev, gccr | GCCR_LTI, GCCR);
121
122 spin_unlock_irqrestore(&priv->lock, flags);
123
124 return 0;
125 }
126
ravb_ptp_adjtime(struct ptp_clock_info * ptp,s64 delta)127 static int ravb_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
128 {
129 struct ravb_private *priv = container_of(ptp, struct ravb_private,
130 ptp.info);
131 struct timespec64 ts;
132 unsigned long flags;
133 int error;
134
135 spin_lock_irqsave(&priv->lock, flags);
136 error = ravb_ptp_time_read(priv, &ts);
137 if (!error) {
138 u64 now = ktime_to_ns(timespec64_to_ktime(ts));
139
140 ts = ns_to_timespec64(now + delta);
141 error = ravb_ptp_time_write(priv, &ts);
142 }
143 spin_unlock_irqrestore(&priv->lock, flags);
144
145 return error;
146 }
147
ravb_ptp_gettime64(struct ptp_clock_info * ptp,struct timespec64 * ts)148 static int ravb_ptp_gettime64(struct ptp_clock_info *ptp, struct timespec64 *ts)
149 {
150 struct ravb_private *priv = container_of(ptp, struct ravb_private,
151 ptp.info);
152 unsigned long flags;
153 int error;
154
155 spin_lock_irqsave(&priv->lock, flags);
156 error = ravb_ptp_time_read(priv, ts);
157 spin_unlock_irqrestore(&priv->lock, flags);
158
159 return error;
160 }
161
ravb_ptp_settime64(struct ptp_clock_info * ptp,const struct timespec64 * ts)162 static int ravb_ptp_settime64(struct ptp_clock_info *ptp,
163 const struct timespec64 *ts)
164 {
165 struct ravb_private *priv = container_of(ptp, struct ravb_private,
166 ptp.info);
167 unsigned long flags;
168 int error;
169
170 spin_lock_irqsave(&priv->lock, flags);
171 error = ravb_ptp_time_write(priv, ts);
172 spin_unlock_irqrestore(&priv->lock, flags);
173
174 return error;
175 }
176
ravb_ptp_extts(struct ptp_clock_info * ptp,struct ptp_extts_request * req,int on)177 static int ravb_ptp_extts(struct ptp_clock_info *ptp,
178 struct ptp_extts_request *req, int on)
179 {
180 struct ravb_private *priv = container_of(ptp, struct ravb_private,
181 ptp.info);
182 struct net_device *ndev = priv->ndev;
183 unsigned long flags;
184
185 /* Reject requests with unsupported flags */
186 if (req->flags & ~(PTP_ENABLE_FEATURE |
187 PTP_RISING_EDGE |
188 PTP_FALLING_EDGE |
189 PTP_STRICT_FLAGS))
190 return -EOPNOTSUPP;
191
192 if (req->index)
193 return -EINVAL;
194
195 if (priv->ptp.extts[req->index] == on)
196 return 0;
197 priv->ptp.extts[req->index] = on;
198
199 spin_lock_irqsave(&priv->lock, flags);
200 if (priv->chip_id == RCAR_GEN2)
201 ravb_modify(ndev, GIC, GIC_PTCE, on ? GIC_PTCE : 0);
202 else if (on)
203 ravb_write(ndev, GIE_PTCS, GIE);
204 else
205 ravb_write(ndev, GID_PTCD, GID);
206 spin_unlock_irqrestore(&priv->lock, flags);
207
208 return 0;
209 }
210
ravb_ptp_perout(struct ptp_clock_info * ptp,struct ptp_perout_request * req,int on)211 static int ravb_ptp_perout(struct ptp_clock_info *ptp,
212 struct ptp_perout_request *req, int on)
213 {
214 struct ravb_private *priv = container_of(ptp, struct ravb_private,
215 ptp.info);
216 struct net_device *ndev = priv->ndev;
217 struct ravb_ptp_perout *perout;
218 unsigned long flags;
219 int error = 0;
220
221 /* Reject requests with unsupported flags */
222 if (req->flags)
223 return -EOPNOTSUPP;
224
225 if (req->index)
226 return -EINVAL;
227
228 if (on) {
229 u64 start_ns;
230 u64 period_ns;
231
232 start_ns = req->start.sec * NSEC_PER_SEC + req->start.nsec;
233 period_ns = req->period.sec * NSEC_PER_SEC + req->period.nsec;
234
235 if (start_ns > U32_MAX) {
236 netdev_warn(ndev,
237 "ptp: start value (nsec) is over limit. Maximum size of start is only 32 bits\n");
238 return -ERANGE;
239 }
240
241 if (period_ns > U32_MAX) {
242 netdev_warn(ndev,
243 "ptp: period value (nsec) is over limit. Maximum size of period is only 32 bits\n");
244 return -ERANGE;
245 }
246
247 spin_lock_irqsave(&priv->lock, flags);
248
249 perout = &priv->ptp.perout[req->index];
250 perout->target = (u32)start_ns;
251 perout->period = (u32)period_ns;
252 error = ravb_ptp_update_compare(priv, (u32)start_ns);
253 if (!error) {
254 /* Unmask interrupt */
255 if (priv->chip_id == RCAR_GEN2)
256 ravb_modify(ndev, GIC, GIC_PTME, GIC_PTME);
257 else
258 ravb_write(ndev, GIE_PTMS0, GIE);
259 }
260 } else {
261 spin_lock_irqsave(&priv->lock, flags);
262
263 perout = &priv->ptp.perout[req->index];
264 perout->period = 0;
265
266 /* Mask interrupt */
267 if (priv->chip_id == RCAR_GEN2)
268 ravb_modify(ndev, GIC, GIC_PTME, 0);
269 else
270 ravb_write(ndev, GID_PTMD0, GID);
271 }
272 spin_unlock_irqrestore(&priv->lock, flags);
273
274 return error;
275 }
276
ravb_ptp_enable(struct ptp_clock_info * ptp,struct ptp_clock_request * req,int on)277 static int ravb_ptp_enable(struct ptp_clock_info *ptp,
278 struct ptp_clock_request *req, int on)
279 {
280 switch (req->type) {
281 case PTP_CLK_REQ_EXTTS:
282 return ravb_ptp_extts(ptp, &req->extts, on);
283 case PTP_CLK_REQ_PEROUT:
284 return ravb_ptp_perout(ptp, &req->perout, on);
285 default:
286 return -EOPNOTSUPP;
287 }
288 }
289
290 static const struct ptp_clock_info ravb_ptp_info = {
291 .owner = THIS_MODULE,
292 .name = "ravb clock",
293 .max_adj = 50000000,
294 .n_ext_ts = N_EXT_TS,
295 .n_per_out = N_PER_OUT,
296 .adjfreq = ravb_ptp_adjfreq,
297 .adjtime = ravb_ptp_adjtime,
298 .gettime64 = ravb_ptp_gettime64,
299 .settime64 = ravb_ptp_settime64,
300 .enable = ravb_ptp_enable,
301 };
302
303 /* Caller must hold the lock */
ravb_ptp_interrupt(struct net_device * ndev)304 void ravb_ptp_interrupt(struct net_device *ndev)
305 {
306 struct ravb_private *priv = netdev_priv(ndev);
307 u32 gis = ravb_read(ndev, GIS);
308
309 gis &= ravb_read(ndev, GIC);
310 if (gis & GIS_PTCF) {
311 struct ptp_clock_event event;
312
313 event.type = PTP_CLOCK_EXTTS;
314 event.index = 0;
315 event.timestamp = ravb_read(ndev, GCPT);
316 ptp_clock_event(priv->ptp.clock, &event);
317 }
318 if (gis & GIS_PTMF) {
319 struct ravb_ptp_perout *perout = priv->ptp.perout;
320
321 if (perout->period) {
322 perout->target += perout->period;
323 ravb_ptp_update_compare(priv, perout->target);
324 }
325 }
326
327 ravb_write(ndev, ~(gis | GIS_RESERVED), GIS);
328 }
329
ravb_ptp_init(struct net_device * ndev,struct platform_device * pdev)330 void ravb_ptp_init(struct net_device *ndev, struct platform_device *pdev)
331 {
332 struct ravb_private *priv = netdev_priv(ndev);
333 unsigned long flags;
334
335 priv->ptp.info = ravb_ptp_info;
336
337 priv->ptp.default_addend = ravb_read(ndev, GTI);
338 priv->ptp.current_addend = priv->ptp.default_addend;
339
340 spin_lock_irqsave(&priv->lock, flags);
341 ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
342 ravb_modify(ndev, GCCR, GCCR_TCSS, GCCR_TCSS_ADJGPTP);
343 spin_unlock_irqrestore(&priv->lock, flags);
344
345 priv->ptp.clock = ptp_clock_register(&priv->ptp.info, &pdev->dev);
346 }
347
ravb_ptp_stop(struct net_device * ndev)348 void ravb_ptp_stop(struct net_device *ndev)
349 {
350 struct ravb_private *priv = netdev_priv(ndev);
351
352 ravb_write(ndev, 0, GIC);
353 ravb_write(ndev, 0, GIS);
354
355 ptp_clock_unregister(priv->ptp.clock);
356 }
357