ravb_ptp.c

  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
 11static 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 */
 25static 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 */
 42static 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 */
 65static 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 */
 91static 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
120static 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
141static 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
155static 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
170static 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	if (req->index)
180		return -EINVAL;
181
182	if (priv->ptp.extts[req->index] == on)
183		return 0;
184	priv->ptp.extts[req->index] = on;
185
186	spin_lock_irqsave(&priv->lock, flags);
187	if (!info->irq_en_dis)
188		ravb_modify(ndev, GIC, GIC_PTCE, on ? GIC_PTCE : 0);
189	else if (on)
190		ravb_write(ndev, GIE_PTCS, GIE);
191	else
192		ravb_write(ndev, GID_PTCD, GID);
193	spin_unlock_irqrestore(&priv->lock, flags);
194
195	return 0;
196}
197
198static int ravb_ptp_perout(struct ptp_clock_info *ptp,
199			   struct ptp_perout_request *req, int on)
200{
201	struct ravb_private *priv = container_of(ptp, struct ravb_private,
202						 ptp.info);
203	const struct ravb_hw_info *info = priv->info;
204	struct net_device *ndev = priv->ndev;
205	struct ravb_ptp_perout *perout;
206	unsigned long flags;
207	int error = 0;
208
209	if (req->index)
210		return -EINVAL;
211
212	if (on) {
213		u64 start_ns;
214		u64 period_ns;
215
216		start_ns = req->start.sec * NSEC_PER_SEC + req->start.nsec;
217		period_ns = req->period.sec * NSEC_PER_SEC + req->period.nsec;
218
219		if (start_ns > U32_MAX) {
220			netdev_warn(ndev,
221				    "ptp: start value (nsec) is over limit. Maximum size of start is only 32 bits\n");
222			return -ERANGE;
223		}
224
225		if (period_ns > U32_MAX) {
226			netdev_warn(ndev,
227				    "ptp: period value (nsec) is over limit. Maximum size of period is only 32 bits\n");
228			return -ERANGE;
229		}
230
231		spin_lock_irqsave(&priv->lock, flags);
232
233		perout = &priv->ptp.perout[req->index];
234		perout->target = (u32)start_ns;
235		perout->period = (u32)period_ns;
236		error = ravb_ptp_update_compare(priv, (u32)start_ns);
237		if (!error) {
238			/* Unmask interrupt */
239			if (!info->irq_en_dis)
240				ravb_modify(ndev, GIC, GIC_PTME, GIC_PTME);
241			else
242				ravb_write(ndev, GIE_PTMS0, GIE);
243		}
244	} else	{
245		spin_lock_irqsave(&priv->lock, flags);
246
247		perout = &priv->ptp.perout[req->index];
248		perout->period = 0;
249
250		/* Mask interrupt */
251		if (!info->irq_en_dis)
252			ravb_modify(ndev, GIC, GIC_PTME, 0);
253		else
254			ravb_write(ndev, GID_PTMD0, GID);
255	}
256	spin_unlock_irqrestore(&priv->lock, flags);
257
258	return error;
259}
260
261static int ravb_ptp_enable(struct ptp_clock_info *ptp,
262			   struct ptp_clock_request *req, int on)
263{
264	switch (req->type) {
265	case PTP_CLK_REQ_EXTTS:
266		return ravb_ptp_extts(ptp, &req->extts, on);
267	case PTP_CLK_REQ_PEROUT:
268		return ravb_ptp_perout(ptp, &req->perout, on);
269	default:
270		return -EOPNOTSUPP;
271	}
272}
273
274static const struct ptp_clock_info ravb_ptp_info = {
275	.owner		= THIS_MODULE,
276	.name		= "ravb clock",
277	.max_adj	= 50000000,
278	.n_ext_ts	= N_EXT_TS,
279	.n_per_out	= N_PER_OUT,
280	.supported_extts_flags = PTP_RISING_EDGE | PTP_FALLING_EDGE,
281	.adjfine	= ravb_ptp_adjfine,
282	.adjtime	= ravb_ptp_adjtime,
283	.gettime64	= ravb_ptp_gettime64,
284	.settime64	= ravb_ptp_settime64,
285	.enable		= ravb_ptp_enable,
286};
287
288/* Caller must hold the lock */
289void ravb_ptp_interrupt(struct net_device *ndev)
290{
291	struct ravb_private *priv = netdev_priv(ndev);
292	u32 gis = ravb_read(ndev, GIS);
293
294	gis &= ravb_read(ndev, GIC);
295	if (gis & GIS_PTCF) {
296		struct ptp_clock_event event;
297
298		event.type = PTP_CLOCK_EXTTS;
299		event.index = 0;
300		event.timestamp = ravb_read(ndev, GCPT);
301		ptp_clock_event(priv->ptp.clock, &event);
302	}
303	if (gis & GIS_PTMF) {
304		struct ravb_ptp_perout *perout = priv->ptp.perout;
305
306		if (perout->period) {
307			perout->target += perout->period;
308			ravb_ptp_update_compare(priv, perout->target);
309		}
310	}
311
312	ravb_write(ndev, ~(gis | GIS_RESERVED), GIS);
313}
314
315void ravb_ptp_init(struct net_device *ndev, struct platform_device *pdev)
316{
317	struct ravb_private *priv = netdev_priv(ndev);
318	unsigned long flags;
319
320	priv->ptp.info = ravb_ptp_info;
321
322	priv->ptp.default_addend = ravb_read(ndev, GTI);
323	priv->ptp.current_addend = priv->ptp.default_addend;
324
325	spin_lock_irqsave(&priv->lock, flags);
326	ravb_wait(ndev, GCCR, GCCR_TCR, GCCR_TCR_NOREQ);
327	ravb_modify(ndev, GCCR, GCCR_TCSS, GCCR_TCSS_ADJGPTP);
328	spin_unlock_irqrestore(&priv->lock, flags);
329
330	priv->ptp.clock = ptp_clock_register(&priv->ptp.info, &pdev->dev);
331}
332
333void ravb_ptp_stop(struct net_device *ndev)
334{
335	struct ravb_private *priv = netdev_priv(ndev);
336
337	ravb_write(ndev, 0, GIC);
338	ravb_write(ndev, 0, GIS);
339
340	ptp_clock_unregister(priv->ptp.clock);
341}