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. <[email protected]>
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_adjfine(struct ptp_clock_info * ptp,long scaled_ppm)91 static int ravb_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
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 addend;
98 u32 gccr;
99
100 addend = (u32)adjust_by_scaled_ppm(priv->ptp.default_addend,
101 scaled_ppm);
102
103 spin_lock_irqsave(&priv->lock, flags);
104
105 priv->ptp.current_addend = addend;
106
107 gccr = ravb_read(ndev, GCCR);
108 if (gccr & GCCR_LTI) {
109 spin_unlock_irqrestore(&priv->lock, flags);
110 return -EBUSY;
111 }
112 ravb_write(ndev, addend & GTI_TIV, GTI);
113 ravb_write(ndev, gccr | GCCR_LTI, GCCR);
114
115 spin_unlock_irqrestore(&priv->lock, flags);
116
117 return 0;
118 }
119
ravb_ptp_adjtime(struct ptp_clock_info * ptp,s64 delta)120 static int ravb_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
121 {
122 struct ravb_private *priv = container_of(ptp, struct ravb_private,
123 ptp.info);
124 struct timespec64 ts;
125 unsigned long flags;
126 int error;
127
128 spin_lock_irqsave(&priv->lock, flags);
129 error = ravb_ptp_time_read(priv, &ts);
130 if (!error) {
131 u64 now = ktime_to_ns(timespec64_to_ktime(ts));
132
133 ts = ns_to_timespec64(now + delta);
134 error = ravb_ptp_time_write(priv, &ts);
135 }
136 spin_unlock_irqrestore(&priv->lock, flags);
137
138 return error;
139 }
140
ravb_ptp_gettime64(struct ptp_clock_info * ptp,struct timespec64 * ts)141 static int ravb_ptp_gettime64(struct ptp_clock_info *ptp, struct timespec64 *ts)
142 {
143 struct ravb_private *priv = container_of(ptp, struct ravb_private,
144 ptp.info);
145 unsigned long flags;
146 int error;
147
148 spin_lock_irqsave(&priv->lock, flags);
149 error = ravb_ptp_time_read(priv, ts);
150 spin_unlock_irqrestore(&priv->lock, flags);
151
152 return error;
153 }
154
ravb_ptp_settime64(struct ptp_clock_info * ptp,const struct timespec64 * ts)155 static int ravb_ptp_settime64(struct ptp_clock_info *ptp,
156 const struct timespec64 *ts)
157 {
158 struct ravb_private *priv = container_of(ptp, struct ravb_private,
159 ptp.info);
160 unsigned long flags;
161 int error;
162
163 spin_lock_irqsave(&priv->lock, flags);
164 error = ravb_ptp_time_write(priv, ts);
165 spin_unlock_irqrestore(&priv->lock, flags);
166
167 return error;
168 }
169
ravb_ptp_extts(struct ptp_clock_info * ptp,struct ptp_extts_request * req,int on)170 static int ravb_ptp_extts(struct ptp_clock_info *ptp,
171 struct ptp_extts_request *req, int on)
172 {
173 struct ravb_private *priv = container_of(ptp, struct ravb_private,
174 ptp.info);
175 const struct ravb_hw_info *info = priv->info;
176 struct net_device *ndev = priv->ndev;
177 unsigned long flags;
178
179 /* Reject requests with unsupported flags */
180 if (req->flags & ~(PTP_ENABLE_FEATURE |
181 PTP_RISING_EDGE |
182 PTP_FALLING_EDGE))
183 return -EOPNOTSUPP;
184
185 if (req->index)
186 return -EINVAL;
187
188 if (priv->ptp.extts[req->index] == on)
189 return 0;
190 priv->ptp.extts[req->index] = on;
191
192 spin_lock_irqsave(&priv->lock, flags);
193 if (!info->irq_en_dis)
194 ravb_modify(ndev, GIC, GIC_PTCE, on ? GIC_PTCE : 0);
195 else if (on)
196 ravb_write(ndev, GIE_PTCS, GIE);
197 else
198 ravb_write(ndev, GID_PTCD, GID);
199 spin_unlock_irqrestore(&priv->lock, flags);
200
201 return 0;
202 }
203
ravb_ptp_perout(struct ptp_clock_info * ptp,struct ptp_perout_request * req,int on)204 static int ravb_ptp_perout(struct ptp_clock_info *ptp,
205 struct ptp_perout_request *req, int on)
206 {
207 struct ravb_private *priv = container_of(ptp, struct ravb_private,
208 ptp.info);
209 const struct ravb_hw_info *info = priv->info;
210 struct net_device *ndev = priv->ndev;
211 struct ravb_ptp_perout *perout;
212 unsigned long flags;
213 int error = 0;
214
215 /* Reject requests with unsupported flags */
216 if (req->flags)
217 return -EOPNOTSUPP;
218
219 if (req->index)
220 return -EINVAL;
221
222 if (on) {
223 u64 start_ns;
224 u64 period_ns;
225
226 start_ns = req->start.sec * NSEC_PER_SEC + req->start.nsec;
227 period_ns = req->period.sec * NSEC_PER_SEC + req->period.nsec;
228
229 if (start_ns > U32_MAX) {
230 netdev_warn(ndev,
231 "ptp: start value (nsec) is over limit. Maximum size of start is only 32 bits\n");
232 return -ERANGE;
233 }
234
235 if (period_ns > U32_MAX) {
236 netdev_warn(ndev,
237 "ptp: period value (nsec) is over limit. Maximum size of period is only 32 bits\n");
238 return -ERANGE;
239 }
240
241 spin_lock_irqsave(&priv->lock, flags);
242
243 perout = &priv->ptp.perout[req->index];
244 perout->target = (u32)start_ns;
245 perout->period = (u32)period_ns;
246 error = ravb_ptp_update_compare(priv, (u32)start_ns);
247 if (!error) {
248 /* Unmask interrupt */
249 if (!info->irq_en_dis)
250 ravb_modify(ndev, GIC, GIC_PTME, GIC_PTME);
251 else
252 ravb_write(ndev, GIE_PTMS0, GIE);
253 }
254 } else {
255 spin_lock_irqsave(&priv->lock, flags);
256
257 perout = &priv->ptp.perout[req->index];
258 perout->period = 0;
259
260 /* Mask interrupt */
261 if (!info->irq_en_dis)
262 ravb_modify(ndev, GIC, GIC_PTME, 0);
263 else
264 ravb_write(ndev, GID_PTMD0, GID);
265 }
266 spin_unlock_irqrestore(&priv->lock, flags);
267
268 return error;
269 }
270
ravb_ptp_enable(struct ptp_clock_info * ptp,struct ptp_clock_request * req,int on)271 static int ravb_ptp_enable(struct ptp_clock_info *ptp,
272 struct ptp_clock_request *req, int on)
273 {
274 switch (req->type) {
275 case PTP_CLK_REQ_EXTTS:
276 return ravb_ptp_extts(ptp, &req->extts, on);
277 case PTP_CLK_REQ_PEROUT:
278 return ravb_ptp_perout(ptp, &req->perout, on);
279 default:
280 return -EOPNOTSUPP;
281 }
282 }
283
284 static const struct ptp_clock_info ravb_ptp_info = {
285 .owner = THIS_MODULE,
286 .name = "ravb clock",
287 .max_adj = 50000000,
288 .n_ext_ts = N_EXT_TS,
289 .n_per_out = N_PER_OUT,
290 .adjfine = ravb_ptp_adjfine,
291 .adjtime = ravb_ptp_adjtime,
292 .gettime64 = ravb_ptp_gettime64,
293 .settime64 = ravb_ptp_settime64,
294 .enable = ravb_ptp_enable,
295 };
296
297 /* Caller must hold the lock */
ravb_ptp_interrupt(struct net_device * ndev)298 void ravb_ptp_interrupt(struct net_device *ndev)
299 {
300 struct ravb_private *priv = netdev_priv(ndev);
301 u32 gis = ravb_read(ndev, GIS);
302
303 gis &= ravb_read(ndev, GIC);
304 if (gis & GIS_PTCF) {
305 struct ptp_clock_event event;
306
307 event.type = PTP_CLOCK_EXTTS;
308 event.index = 0;
309 event.timestamp = ravb_read(ndev, GCPT);
310 ptp_clock_event(priv->ptp.clock, &event);
311 }
312 if (gis & GIS_PTMF) {
313 struct ravb_ptp_perout *perout = priv->ptp.perout;
314
315 if (perout->period) {
316 perout->target += perout->period;
317 ravb_ptp_update_compare(priv, perout->target);
318 }
319 }
320
321 ravb_write(ndev, ~(gis | GIS_RESERVED), GIS);
322 }
323
ravb_ptp_init(struct net_device * ndev,struct platform_device * pdev)324 void ravb_ptp_init(struct net_device *ndev, struct platform_device *pdev)
325 {
326 struct ravb_private *priv = netdev_priv(ndev);
327 unsigned long flags;
328
329 priv->ptp.info = ravb_ptp_info;
330
331 priv->ptp.default_addend = ravb_read(ndev, GTI);
332 priv->ptp.current_addend = priv->ptp.default_addend;
333
334 spin_lock_irqsave(&priv->lock, flags);
335 ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
336 ravb_modify(ndev, GCCR, GCCR_TCSS, GCCR_TCSS_ADJGPTP);
337 spin_unlock_irqrestore(&priv->lock, flags);
338
339 priv->ptp.clock = ptp_clock_register(&priv->ptp.info, &pdev->dev);
340 }
341
ravb_ptp_stop(struct net_device * ndev)342 void ravb_ptp_stop(struct net_device *ndev)
343 {
344 struct ravb_private *priv = netdev_priv(ndev);
345
346 ravb_write(ndev, 0, GIC);
347 ravb_write(ndev, 0, GIS);
348
349 ptp_clock_unregister(priv->ptp.clock);
350 }
351