xref: /linux/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*******************************************************************************
3   PTP 1588 clock using the STMMAC.
4 
5   Copyright (C) 2013  Vayavya Labs Pvt Ltd
6 
7 
8   Author: Rayagond Kokatanur <rayagond@vayavyalabs.com>
9 *******************************************************************************/
10 #include "stmmac.h"
11 #include "stmmac_ptp.h"
12 
13 /**
14  * stmmac_adjust_freq
15  *
16  * @ptp: pointer to ptp_clock_info structure
17  * @scaled_ppm: desired period change in scaled parts per million
18  *
19  * Description: this function will adjust the frequency of hardware clock.
20  *
21  * Scaled parts per million is ppm with a 16-bit binary fractional field.
22  */
23 static int stmmac_adjust_freq(struct ptp_clock_info *ptp, long scaled_ppm)
24 {
25 	struct stmmac_priv *priv =
26 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
27 	unsigned long flags;
28 	u32 addend;
29 
30 	addend = adjust_by_scaled_ppm(priv->default_addend, scaled_ppm);
31 
32 	write_lock_irqsave(&priv->ptp_lock, flags);
33 	stmmac_config_addend(priv, priv->ptpaddr, addend);
34 	write_unlock_irqrestore(&priv->ptp_lock, flags);
35 
36 	return 0;
37 }
38 
39 /**
40  * stmmac_adjust_time
41  *
42  * @ptp: pointer to ptp_clock_info structure
43  * @delta: desired change in nanoseconds
44  *
45  * Description: this function will shift/adjust the hardware clock time.
46  */
47 static int stmmac_adjust_time(struct ptp_clock_info *ptp, s64 delta)
48 {
49 	struct stmmac_priv *priv =
50 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
51 	unsigned long flags;
52 	u32 sec, nsec;
53 	u32 quotient, reminder;
54 	int neg_adj = 0;
55 	bool xmac, est_rst = false;
56 	int ret;
57 
58 	xmac = priv->plat->has_gmac4 || priv->plat->has_xgmac;
59 
60 	if (delta < 0) {
61 		neg_adj = 1;
62 		delta = -delta;
63 	}
64 
65 	quotient = div_u64_rem(delta, 1000000000ULL, &reminder);
66 	sec = quotient;
67 	nsec = reminder;
68 
69 	/* If EST is enabled, disabled it before adjust ptp time. */
70 	if (priv->est && priv->est->enable) {
71 		est_rst = true;
72 		mutex_lock(&priv->est_lock);
73 		priv->est->enable = false;
74 		stmmac_est_configure(priv, priv, priv->est,
75 				     priv->plat->clk_ptp_rate);
76 		mutex_unlock(&priv->est_lock);
77 	}
78 
79 	write_lock_irqsave(&priv->ptp_lock, flags);
80 	stmmac_adjust_systime(priv, priv->ptpaddr, sec, nsec, neg_adj, xmac);
81 	write_unlock_irqrestore(&priv->ptp_lock, flags);
82 
83 	/* Calculate new basetime and re-configured EST after PTP time adjust. */
84 	if (est_rst) {
85 		struct timespec64 current_time, time;
86 		ktime_t current_time_ns, basetime;
87 		u64 cycle_time;
88 
89 		mutex_lock(&priv->est_lock);
90 		priv->ptp_clock_ops.gettime64(&priv->ptp_clock_ops, &current_time);
91 		current_time_ns = timespec64_to_ktime(current_time);
92 		time.tv_nsec = priv->est->btr_reserve[0];
93 		time.tv_sec = priv->est->btr_reserve[1];
94 		basetime = timespec64_to_ktime(time);
95 		cycle_time = (u64)priv->est->ctr[1] * NSEC_PER_SEC +
96 			     priv->est->ctr[0];
97 		time = stmmac_calc_tas_basetime(basetime,
98 						current_time_ns,
99 						cycle_time);
100 
101 		priv->est->btr[0] = (u32)time.tv_nsec;
102 		priv->est->btr[1] = (u32)time.tv_sec;
103 		priv->est->enable = true;
104 		ret = stmmac_est_configure(priv, priv, priv->est,
105 					   priv->plat->clk_ptp_rate);
106 		mutex_unlock(&priv->est_lock);
107 		if (ret)
108 			netdev_err(priv->dev, "failed to configure EST\n");
109 	}
110 
111 	return 0;
112 }
113 
114 /**
115  * stmmac_get_time
116  *
117  * @ptp: pointer to ptp_clock_info structure
118  * @ts: pointer to hold time/result
119  *
120  * Description: this function will read the current time from the
121  * hardware clock and store it in @ts.
122  */
123 static int stmmac_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts)
124 {
125 	struct stmmac_priv *priv =
126 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
127 	unsigned long flags;
128 	u64 ns = 0;
129 
130 	read_lock_irqsave(&priv->ptp_lock, flags);
131 	stmmac_get_systime(priv, priv->ptpaddr, &ns);
132 	read_unlock_irqrestore(&priv->ptp_lock, flags);
133 
134 	*ts = ns_to_timespec64(ns);
135 
136 	return 0;
137 }
138 
139 /**
140  * stmmac_set_time
141  *
142  * @ptp: pointer to ptp_clock_info structure
143  * @ts: time value to set
144  *
145  * Description: this function will set the current time on the
146  * hardware clock.
147  */
148 static int stmmac_set_time(struct ptp_clock_info *ptp,
149 			   const struct timespec64 *ts)
150 {
151 	struct stmmac_priv *priv =
152 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
153 	unsigned long flags;
154 
155 	write_lock_irqsave(&priv->ptp_lock, flags);
156 	stmmac_init_systime(priv, priv->ptpaddr, ts->tv_sec, ts->tv_nsec);
157 	write_unlock_irqrestore(&priv->ptp_lock, flags);
158 
159 	return 0;
160 }
161 
162 static int stmmac_enable(struct ptp_clock_info *ptp,
163 			 struct ptp_clock_request *rq, int on)
164 {
165 	struct stmmac_priv *priv =
166 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
167 	void __iomem *ptpaddr = priv->ptpaddr;
168 	struct stmmac_pps_cfg *cfg;
169 	int ret = -EOPNOTSUPP;
170 	unsigned long flags;
171 	u32 acr_value;
172 
173 	switch (rq->type) {
174 	case PTP_CLK_REQ_PEROUT:
175 		/* Reject requests with unsupported flags */
176 		if (rq->perout.flags)
177 			return -EOPNOTSUPP;
178 
179 		cfg = &priv->pps[rq->perout.index];
180 
181 		cfg->start.tv_sec = rq->perout.start.sec;
182 		cfg->start.tv_nsec = rq->perout.start.nsec;
183 		cfg->period.tv_sec = rq->perout.period.sec;
184 		cfg->period.tv_nsec = rq->perout.period.nsec;
185 
186 		write_lock_irqsave(&priv->ptp_lock, flags);
187 		ret = stmmac_flex_pps_config(priv, priv->ioaddr,
188 					     rq->perout.index, cfg, on,
189 					     priv->sub_second_inc,
190 					     priv->systime_flags);
191 		write_unlock_irqrestore(&priv->ptp_lock, flags);
192 		break;
193 	case PTP_CLK_REQ_EXTTS: {
194 		u8 channel;
195 
196 		mutex_lock(&priv->aux_ts_lock);
197 		acr_value = readl(ptpaddr + PTP_ACR);
198 		channel = ilog2(FIELD_GET(PTP_ACR_MASK, acr_value));
199 		acr_value &= ~PTP_ACR_MASK;
200 
201 		if (on) {
202 			if (FIELD_GET(PTP_ACR_MASK, acr_value)) {
203 				netdev_err(priv->dev,
204 					   "Cannot enable auxiliary snapshot %d as auxiliary snapshot %d is already enabled",
205 					rq->extts.index, channel);
206 				mutex_unlock(&priv->aux_ts_lock);
207 				return -EBUSY;
208 			}
209 
210 			priv->plat->flags |= STMMAC_FLAG_EXT_SNAPSHOT_EN;
211 
212 			/* Enable External snapshot trigger */
213 			acr_value |= PTP_ACR_ATSEN(rq->extts.index);
214 			acr_value |= PTP_ACR_ATSFC;
215 		} else {
216 			priv->plat->flags &= ~STMMAC_FLAG_EXT_SNAPSHOT_EN;
217 		}
218 		netdev_dbg(priv->dev, "Auxiliary Snapshot %d %s.\n",
219 			   rq->extts.index, on ? "enabled" : "disabled");
220 		writel(acr_value, ptpaddr + PTP_ACR);
221 		mutex_unlock(&priv->aux_ts_lock);
222 		/* wait for auxts fifo clear to finish */
223 		ret = readl_poll_timeout(ptpaddr + PTP_ACR, acr_value,
224 					 !(acr_value & PTP_ACR_ATSFC),
225 					 10, 10000);
226 		break;
227 	}
228 
229 	default:
230 		break;
231 	}
232 
233 	return ret;
234 }
235 
236 /**
237  * stmmac_get_syncdevicetime
238  * @device: current device time
239  * @system: system counter value read synchronously with device time
240  * @ctx: context provided by timekeeping code
241  * Description: Read device and system clock simultaneously and return the
242  * corrected clock values in ns.
243  **/
244 static int stmmac_get_syncdevicetime(ktime_t *device,
245 				     struct system_counterval_t *system,
246 				     void *ctx)
247 {
248 	struct stmmac_priv *priv = (struct stmmac_priv *)ctx;
249 
250 	if (priv->plat->crosststamp)
251 		return priv->plat->crosststamp(device, system, ctx);
252 	else
253 		return -EOPNOTSUPP;
254 }
255 
256 static int stmmac_getcrosststamp(struct ptp_clock_info *ptp,
257 				 struct system_device_crosststamp *xtstamp)
258 {
259 	struct stmmac_priv *priv =
260 		container_of(ptp, struct stmmac_priv, ptp_clock_ops);
261 
262 	return get_device_system_crosststamp(stmmac_get_syncdevicetime,
263 					     priv, NULL, xtstamp);
264 }
265 
266 /* structure describing a PTP hardware clock */
267 const struct ptp_clock_info stmmac_ptp_clock_ops = {
268 	.owner = THIS_MODULE,
269 	.name = "stmmac ptp",
270 	.max_adj = 62500000,
271 	.n_alarm = 0,
272 	.n_ext_ts = 0, /* will be overwritten in stmmac_ptp_register */
273 	.n_per_out = 0, /* will be overwritten in stmmac_ptp_register */
274 	.n_pins = 0,
275 	.pps = 0,
276 	.adjfine = stmmac_adjust_freq,
277 	.adjtime = stmmac_adjust_time,
278 	.gettime64 = stmmac_get_time,
279 	.settime64 = stmmac_set_time,
280 	.enable = stmmac_enable,
281 	.getcrosststamp = stmmac_getcrosststamp,
282 };
283 
284 /* structure describing a PTP hardware clock */
285 const struct ptp_clock_info dwmac1000_ptp_clock_ops = {
286 	.owner = THIS_MODULE,
287 	.name = "stmmac ptp",
288 	.max_adj = 62500000,
289 	.n_alarm = 0,
290 	.n_ext_ts = 1,
291 	.n_per_out = 0,
292 	.n_pins = 0,
293 	.pps = 0,
294 	.adjfine = stmmac_adjust_freq,
295 	.adjtime = stmmac_adjust_time,
296 	.gettime64 = stmmac_get_time,
297 	.settime64 = stmmac_set_time,
298 	.enable = dwmac1000_ptp_enable,
299 	.getcrosststamp = stmmac_getcrosststamp,
300 };
301 
302 /**
303  * stmmac_ptp_register
304  * @priv: driver private structure
305  * Description: this function will register the ptp clock driver
306  * to kernel. It also does some house keeping work.
307  */
308 void stmmac_ptp_register(struct stmmac_priv *priv)
309 {
310 	int i;
311 
312 	for (i = 0; i < priv->dma_cap.pps_out_num; i++) {
313 		if (i >= STMMAC_PPS_MAX)
314 			break;
315 		priv->pps[i].available = true;
316 	}
317 
318 	/* Calculate the clock domain crossing (CDC) error if necessary */
319 	priv->plat->cdc_error_adj = 0;
320 	if (priv->plat->has_gmac4 && priv->plat->clk_ptp_rate)
321 		priv->plat->cdc_error_adj = (2 * NSEC_PER_SEC) / priv->plat->clk_ptp_rate;
322 
323 	/* Update the ptp clock parameters based on feature discovery, when
324 	 * available
325 	 */
326 	if (priv->dma_cap.pps_out_num)
327 		priv->ptp_clock_ops.n_per_out = priv->dma_cap.pps_out_num;
328 
329 	if (priv->dma_cap.aux_snapshot_n)
330 		priv->ptp_clock_ops.n_ext_ts = priv->dma_cap.aux_snapshot_n;
331 
332 	if (priv->plat->ptp_max_adj)
333 		priv->ptp_clock_ops.max_adj = priv->plat->ptp_max_adj;
334 
335 	rwlock_init(&priv->ptp_lock);
336 	mutex_init(&priv->aux_ts_lock);
337 
338 	priv->ptp_clock = ptp_clock_register(&priv->ptp_clock_ops,
339 					     priv->device);
340 	if (IS_ERR(priv->ptp_clock)) {
341 		netdev_err(priv->dev, "ptp_clock_register failed\n");
342 		priv->ptp_clock = NULL;
343 	} else if (priv->ptp_clock)
344 		netdev_info(priv->dev, "registered PTP clock\n");
345 }
346 
347 /**
348  * stmmac_ptp_unregister
349  * @priv: driver private structure
350  * Description: this function will remove/unregister the ptp clock driver
351  * from the kernel.
352  */
353 void stmmac_ptp_unregister(struct stmmac_priv *priv)
354 {
355 	if (priv->ptp_clock) {
356 		ptp_clock_unregister(priv->ptp_clock);
357 		priv->ptp_clock = NULL;
358 		pr_debug("Removed PTP HW clock successfully on %s\n",
359 			 priv->dev->name);
360 	}
361 
362 	mutex_destroy(&priv->aux_ts_lock);
363 }
364