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 
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 */
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 */
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 */
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 */
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 
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 
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 
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 
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 			   PTP_STRICT_FLAGS))
184 		return -EOPNOTSUPP;
185 
186 	if (req->index)
187 		return -EINVAL;
188 
189 	if (priv->ptp.extts[req->index] == on)
190 		return 0;
191 	priv->ptp.extts[req->index] = on;
192 
193 	spin_lock_irqsave(&priv->lock, flags);
194 	if (!info->irq_en_dis)
195 		ravb_modify(ndev, GIC, GIC_PTCE, on ? GIC_PTCE : 0);
196 	else if (on)
197 		ravb_write(ndev, GIE_PTCS, GIE);
198 	else
199 		ravb_write(ndev, GID_PTCD, GID);
200 	spin_unlock_irqrestore(&priv->lock, flags);
201 
202 	return 0;
203 }
204 
205 static int ravb_ptp_perout(struct ptp_clock_info *ptp,
206 			   struct ptp_perout_request *req, int on)
207 {
208 	struct ravb_private *priv = container_of(ptp, struct ravb_private,
209 						 ptp.info);
210 	const struct ravb_hw_info *info = priv->info;
211 	struct net_device *ndev = priv->ndev;
212 	struct ravb_ptp_perout *perout;
213 	unsigned long flags;
214 	int error = 0;
215 
216 	/* Reject requests with unsupported flags */
217 	if (req->flags)
218 		return -EOPNOTSUPP;
219 
220 	if (req->index)
221 		return -EINVAL;
222 
223 	if (on) {
224 		u64 start_ns;
225 		u64 period_ns;
226 
227 		start_ns = req->start.sec * NSEC_PER_SEC + req->start.nsec;
228 		period_ns = req->period.sec * NSEC_PER_SEC + req->period.nsec;
229 
230 		if (start_ns > U32_MAX) {
231 			netdev_warn(ndev,
232 				    "ptp: start value (nsec) is over limit. Maximum size of start is only 32 bits\n");
233 			return -ERANGE;
234 		}
235 
236 		if (period_ns > U32_MAX) {
237 			netdev_warn(ndev,
238 				    "ptp: period value (nsec) is over limit. Maximum size of period is only 32 bits\n");
239 			return -ERANGE;
240 		}
241 
242 		spin_lock_irqsave(&priv->lock, flags);
243 
244 		perout = &priv->ptp.perout[req->index];
245 		perout->target = (u32)start_ns;
246 		perout->period = (u32)period_ns;
247 		error = ravb_ptp_update_compare(priv, (u32)start_ns);
248 		if (!error) {
249 			/* Unmask interrupt */
250 			if (!info->irq_en_dis)
251 				ravb_modify(ndev, GIC, GIC_PTME, GIC_PTME);
252 			else
253 				ravb_write(ndev, GIE_PTMS0, GIE);
254 		}
255 	} else	{
256 		spin_lock_irqsave(&priv->lock, flags);
257 
258 		perout = &priv->ptp.perout[req->index];
259 		perout->period = 0;
260 
261 		/* Mask interrupt */
262 		if (!info->irq_en_dis)
263 			ravb_modify(ndev, GIC, GIC_PTME, 0);
264 		else
265 			ravb_write(ndev, GID_PTMD0, GID);
266 	}
267 	spin_unlock_irqrestore(&priv->lock, flags);
268 
269 	return error;
270 }
271 
272 static int ravb_ptp_enable(struct ptp_clock_info *ptp,
273 			   struct ptp_clock_request *req, int on)
274 {
275 	switch (req->type) {
276 	case PTP_CLK_REQ_EXTTS:
277 		return ravb_ptp_extts(ptp, &req->extts, on);
278 	case PTP_CLK_REQ_PEROUT:
279 		return ravb_ptp_perout(ptp, &req->perout, on);
280 	default:
281 		return -EOPNOTSUPP;
282 	}
283 }
284 
285 static const struct ptp_clock_info ravb_ptp_info = {
286 	.owner		= THIS_MODULE,
287 	.name		= "ravb clock",
288 	.max_adj	= 50000000,
289 	.n_ext_ts	= N_EXT_TS,
290 	.n_per_out	= N_PER_OUT,
291 	.adjfine	= ravb_ptp_adjfine,
292 	.adjtime	= ravb_ptp_adjtime,
293 	.gettime64	= ravb_ptp_gettime64,
294 	.settime64	= ravb_ptp_settime64,
295 	.enable		= ravb_ptp_enable,
296 };
297 
298 /* Caller must hold the lock */
299 void ravb_ptp_interrupt(struct net_device *ndev)
300 {
301 	struct ravb_private *priv = netdev_priv(ndev);
302 	u32 gis = ravb_read(ndev, GIS);
303 
304 	gis &= ravb_read(ndev, GIC);
305 	if (gis & GIS_PTCF) {
306 		struct ptp_clock_event event;
307 
308 		event.type = PTP_CLOCK_EXTTS;
309 		event.index = 0;
310 		event.timestamp = ravb_read(ndev, GCPT);
311 		ptp_clock_event(priv->ptp.clock, &event);
312 	}
313 	if (gis & GIS_PTMF) {
314 		struct ravb_ptp_perout *perout = priv->ptp.perout;
315 
316 		if (perout->period) {
317 			perout->target += perout->period;
318 			ravb_ptp_update_compare(priv, perout->target);
319 		}
320 	}
321 
322 	ravb_write(ndev, ~(gis | GIS_RESERVED), GIS);
323 }
324 
325 void ravb_ptp_init(struct net_device *ndev, struct platform_device *pdev)
326 {
327 	struct ravb_private *priv = netdev_priv(ndev);
328 	unsigned long flags;
329 
330 	priv->ptp.info = ravb_ptp_info;
331 
332 	priv->ptp.default_addend = ravb_read(ndev, GTI);
333 	priv->ptp.current_addend = priv->ptp.default_addend;
334 
335 	spin_lock_irqsave(&priv->lock, flags);
336 	ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
337 	ravb_modify(ndev, GCCR, GCCR_TCSS, GCCR_TCSS_ADJGPTP);
338 	spin_unlock_irqrestore(&priv->lock, flags);
339 
340 	priv->ptp.clock = ptp_clock_register(&priv->ptp.info, &pdev->dev);
341 }
342 
343 void ravb_ptp_stop(struct net_device *ndev)
344 {
345 	struct ravb_private *priv = netdev_priv(ndev);
346 
347 	ravb_write(ndev, 0, GIC);
348 	ravb_write(ndev, 0, GIS);
349 
350 	ptp_clock_unregister(priv->ptp.clock);
351 }
352