ravb_ptp.c 8.55 KB
Newer Older
1
// SPDX-License-Identifier: GPL-2.0+
2
3
4
5
/* PTP 1588 clock using the Renesas Ethernet AVB
 *
 * Copyright (C) 2013-2015 Renesas Electronics Corporation
 * Copyright (C) 2015 Renesas Solutions Corp.
6
 * Copyright (C) 2015-2016 Cogent Embedded, Inc. <source@cogentembedded.com>
7
8
9
10
11
12
13
14
15
16
17
18
19
 */

#include "ravb.h"

static int ravb_ptp_tcr_request(struct ravb_private *priv, u32 request)
{
	struct net_device *ndev = priv->ndev;
	int error;

	error = ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
	if (error)
		return error;

20
	ravb_modify(ndev, GCCR, request, request);
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
	return ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
}

/* Caller must hold the lock */
static int ravb_ptp_time_read(struct ravb_private *priv, struct timespec64 *ts)
{
	struct net_device *ndev = priv->ndev;
	int error;

	error = ravb_ptp_tcr_request(priv, GCCR_TCR_CAPTURE);
	if (error)
		return error;

	ts->tv_nsec = ravb_read(ndev, GCT0);
	ts->tv_sec  = ravb_read(ndev, GCT1) |
		((s64)ravb_read(ndev, GCT2) << 32);

	return 0;
}

/* Caller must hold the lock */
static int ravb_ptp_time_write(struct ravb_private *priv,
				const struct timespec64 *ts)
{
	struct net_device *ndev = priv->ndev;
	int error;
	u32 gccr;

	error = ravb_ptp_tcr_request(priv, GCCR_TCR_RESET);
	if (error)
		return error;

	gccr = ravb_read(ndev, GCCR);
	if (gccr & GCCR_LTO)
		return -EBUSY;
	ravb_write(ndev, ts->tv_nsec, GTO0);
	ravb_write(ndev, ts->tv_sec,  GTO1);
	ravb_write(ndev, (ts->tv_sec >> 32) & 0xffff, GTO2);
	ravb_write(ndev, gccr | GCCR_LTO, GCCR);

	return 0;
}

/* Caller must hold the lock */
static int ravb_ptp_update_compare(struct ravb_private *priv, u32 ns)
{
	struct net_device *ndev = priv->ndev;
	/* When the comparison value (GPTC.PTCV) is in range of
	 * [x-1 to x+1] (x is the configured increment value in
	 * GTI.TIV), it may happen that a comparison match is
	 * not detected when the timer wraps around.
	 */
	u32 gti_ns_plus_1 = (priv->ptp.current_addend >> 20) + 1;
	u32 gccr;

	if (ns < gti_ns_plus_1)
		ns = gti_ns_plus_1;
	else if (ns > 0 - gti_ns_plus_1)
		ns = 0 - gti_ns_plus_1;

	gccr = ravb_read(ndev, GCCR);
	if (gccr & GCCR_LPTC)
		return -EBUSY;
	ravb_write(ndev, ns, GPTC);
	ravb_write(ndev, gccr | GCCR_LPTC, GCCR);

	return 0;
}

/* PTP clock operations */
static int ravb_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
{
	struct ravb_private *priv = container_of(ptp, struct ravb_private,
						 ptp.info);
	struct net_device *ndev = priv->ndev;
	unsigned long flags;
	u32 diff, addend;
	bool neg_adj = false;
	u32 gccr;

	if (ppb < 0) {
		neg_adj = true;
		ppb = -ppb;
	}
	addend = priv->ptp.default_addend;
	diff = div_u64((u64)addend * ppb, NSEC_PER_SEC);

	addend = neg_adj ? addend - diff : addend + diff;

	spin_lock_irqsave(&priv->lock, flags);

	priv->ptp.current_addend = addend;

	gccr = ravb_read(ndev, GCCR);
115
116
	if (gccr & GCCR_LTI) {
		spin_unlock_irqrestore(&priv->lock, flags);
117
		return -EBUSY;
118
	}
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
	ravb_write(ndev, addend & GTI_TIV, GTI);
	ravb_write(ndev, gccr | GCCR_LTI, GCCR);

	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static int ravb_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
	struct ravb_private *priv = container_of(ptp, struct ravb_private,
						 ptp.info);
	struct timespec64 ts;
	unsigned long flags;
	int error;

	spin_lock_irqsave(&priv->lock, flags);
	error = ravb_ptp_time_read(priv, &ts);
	if (!error) {
		u64 now = ktime_to_ns(timespec64_to_ktime(ts));

		ts = ns_to_timespec64(now + delta);
		error = ravb_ptp_time_write(priv, &ts);
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	return error;
}

static int ravb_ptp_gettime64(struct ptp_clock_info *ptp, struct timespec64 *ts)
{
	struct ravb_private *priv = container_of(ptp, struct ravb_private,
						 ptp.info);
	unsigned long flags;
	int error;

	spin_lock_irqsave(&priv->lock, flags);
	error = ravb_ptp_time_read(priv, ts);
	spin_unlock_irqrestore(&priv->lock, flags);

	return error;
}

static int ravb_ptp_settime64(struct ptp_clock_info *ptp,
			      const struct timespec64 *ts)
{
	struct ravb_private *priv = container_of(ptp, struct ravb_private,
						 ptp.info);
	unsigned long flags;
	int error;

	spin_lock_irqsave(&priv->lock, flags);
	error = ravb_ptp_time_write(priv, ts);
	spin_unlock_irqrestore(&priv->lock, flags);

	return error;
}

static int ravb_ptp_extts(struct ptp_clock_info *ptp,
			  struct ptp_extts_request *req, int on)
{
	struct ravb_private *priv = container_of(ptp, struct ravb_private,
						 ptp.info);
	struct net_device *ndev = priv->ndev;
	unsigned long flags;

185
186
187
	/* Reject requests with unsupported flags */
	if (req->flags & ~(PTP_ENABLE_FEATURE |
			   PTP_RISING_EDGE |
188
189
			   PTP_FALLING_EDGE |
			   PTP_STRICT_FLAGS))
190
191
		return -EOPNOTSUPP;

192
193
194
195
196
197
198
199
	if (req->index)
		return -EINVAL;

	if (priv->ptp.extts[req->index] == on)
		return 0;
	priv->ptp.extts[req->index] = on;

	spin_lock_irqsave(&priv->lock, flags);
200
201
202
203
204
205
	if (priv->chip_id == RCAR_GEN2)
		ravb_modify(ndev, GIC, GIC_PTCE, on ? GIC_PTCE : 0);
	else if (on)
		ravb_write(ndev, GIE_PTCS, GIE);
	else
		ravb_write(ndev, GID_PTCD, GID);
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static int ravb_ptp_perout(struct ptp_clock_info *ptp,
			   struct ptp_perout_request *req, int on)
{
	struct ravb_private *priv = container_of(ptp, struct ravb_private,
						 ptp.info);
	struct net_device *ndev = priv->ndev;
	struct ravb_ptp_perout *perout;
	unsigned long flags;
	int error = 0;

221
222
223
224
	/* Reject requests with unsupported flags */
	if (req->flags)
		return -EOPNOTSUPP;

225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
	if (req->index)
		return -EINVAL;

	if (on) {
		u64 start_ns;
		u64 period_ns;

		start_ns = req->start.sec * NSEC_PER_SEC + req->start.nsec;
		period_ns = req->period.sec * NSEC_PER_SEC + req->period.nsec;

		if (start_ns > U32_MAX) {
			netdev_warn(ndev,
				    "ptp: start value (nsec) is over limit. Maximum size of start is only 32 bits\n");
			return -ERANGE;
		}

		if (period_ns > U32_MAX) {
			netdev_warn(ndev,
				    "ptp: period value (nsec) is over limit. Maximum size of period is only 32 bits\n");
			return -ERANGE;
		}

		spin_lock_irqsave(&priv->lock, flags);

		perout = &priv->ptp.perout[req->index];
		perout->target = (u32)start_ns;
		perout->period = (u32)period_ns;
		error = ravb_ptp_update_compare(priv, (u32)start_ns);
		if (!error) {
			/* Unmask interrupt */
255
256
257
258
			if (priv->chip_id == RCAR_GEN2)
				ravb_modify(ndev, GIC, GIC_PTME, GIC_PTME);
			else
				ravb_write(ndev, GIE_PTMS0, GIE);
259
260
261
262
263
264
265
266
		}
	} else	{
		spin_lock_irqsave(&priv->lock, flags);

		perout = &priv->ptp.perout[req->index];
		perout->period = 0;

		/* Mask interrupt */
267
268
269
270
		if (priv->chip_id == RCAR_GEN2)
			ravb_modify(ndev, GIC, GIC_PTME, 0);
		else
			ravb_write(ndev, GID_PTMD0, GID);
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	return error;
}

static int ravb_ptp_enable(struct ptp_clock_info *ptp,
			   struct ptp_clock_request *req, int on)
{
	switch (req->type) {
	case PTP_CLK_REQ_EXTTS:
		return ravb_ptp_extts(ptp, &req->extts, on);
	case PTP_CLK_REQ_PEROUT:
		return ravb_ptp_perout(ptp, &req->perout, on);
	default:
		return -EOPNOTSUPP;
	}
}

static const struct ptp_clock_info ravb_ptp_info = {
	.owner		= THIS_MODULE,
	.name		= "ravb clock",
	.max_adj	= 50000000,
	.n_ext_ts	= N_EXT_TS,
	.n_per_out	= N_PER_OUT,
	.adjfreq	= ravb_ptp_adjfreq,
	.adjtime	= ravb_ptp_adjtime,
	.gettime64	= ravb_ptp_gettime64,
	.settime64	= ravb_ptp_settime64,
	.enable		= ravb_ptp_enable,
};

/* Caller must hold the lock */
304
void ravb_ptp_interrupt(struct net_device *ndev)
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
{
	struct ravb_private *priv = netdev_priv(ndev);
	u32 gis = ravb_read(ndev, GIS);

	gis &= ravb_read(ndev, GIC);
	if (gis & GIS_PTCF) {
		struct ptp_clock_event event;

		event.type = PTP_CLOCK_EXTTS;
		event.index = 0;
		event.timestamp = ravb_read(ndev, GCPT);
		ptp_clock_event(priv->ptp.clock, &event);
	}
	if (gis & GIS_PTMF) {
		struct ravb_ptp_perout *perout = priv->ptp.perout;

		if (perout->period) {
			perout->target += perout->period;
			ravb_ptp_update_compare(priv, perout->target);
		}
	}

327
	ravb_write(ndev, ~(gis | GIS_RESERVED), GIS);
328
329
330
331
332
333
334
335
336
337
338
339
340
341
}

void ravb_ptp_init(struct net_device *ndev, struct platform_device *pdev)
{
	struct ravb_private *priv = netdev_priv(ndev);
	unsigned long flags;

	priv->ptp.info = ravb_ptp_info;

	priv->ptp.default_addend = ravb_read(ndev, GTI);
	priv->ptp.current_addend = priv->ptp.default_addend;

	spin_lock_irqsave(&priv->lock, flags);
	ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
342
	ravb_modify(ndev, GCCR, GCCR_TCSS, GCCR_TCSS_ADJGPTP);
343
344
345
346
347
348
349
350
351
352
353
354
355
356
	spin_unlock_irqrestore(&priv->lock, flags);

	priv->ptp.clock = ptp_clock_register(&priv->ptp.info, &pdev->dev);
}

void ravb_ptp_stop(struct net_device *ndev)
{
	struct ravb_private *priv = netdev_priv(ndev);

	ravb_write(ndev, 0, GIC);
	ravb_write(ndev, 0, GIS);

	ptp_clock_unregister(priv->ptp.clock);
}