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 #include "dwmac4.h"
13 
14 /**
15  * stmmac_adjust_freq
16  *
17  * @ptp: pointer to ptp_clock_info structure
18  * @ppb: desired period change in parts ber billion
19  *
20  * Description: this function will adjust the frequency of hardware clock.
21  */
22 static int stmmac_adjust_freq(struct ptp_clock_info *ptp, s32 ppb)
23 {
24 	struct stmmac_priv *priv =
25 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
26 	unsigned long flags;
27 	u32 diff, addend;
28 	int neg_adj = 0;
29 	u64 adj;
30 
31 	if (ppb < 0) {
32 		neg_adj = 1;
33 		ppb = -ppb;
34 	}
35 
36 	addend = priv->default_addend;
37 	adj = addend;
38 	adj *= ppb;
39 	diff = div_u64(adj, 1000000000ULL);
40 	addend = neg_adj ? (addend - diff) : (addend + diff);
41 
42 	spin_lock_irqsave(&priv->ptp_lock, flags);
43 	stmmac_config_addend(priv, priv->ptpaddr, addend);
44 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
45 
46 	return 0;
47 }
48 
49 /**
50  * stmmac_adjust_time
51  *
52  * @ptp: pointer to ptp_clock_info structure
53  * @delta: desired change in nanoseconds
54  *
55  * Description: this function will shift/adjust the hardware clock time.
56  */
57 static int stmmac_adjust_time(struct ptp_clock_info *ptp, s64 delta)
58 {
59 	struct stmmac_priv *priv =
60 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
61 	unsigned long flags;
62 	u32 sec, nsec;
63 	u32 quotient, reminder;
64 	int neg_adj = 0;
65 	bool xmac, est_rst = false;
66 	int ret;
67 
68 	xmac = priv->plat->has_gmac4 || priv->plat->has_xgmac;
69 
70 	if (delta < 0) {
71 		neg_adj = 1;
72 		delta = -delta;
73 	}
74 
75 	quotient = div_u64_rem(delta, 1000000000ULL, &reminder);
76 	sec = quotient;
77 	nsec = reminder;
78 
79 	/* If EST is enabled, disabled it before adjust ptp time. */
80 	if (priv->plat->est && priv->plat->est->enable) {
81 		est_rst = true;
82 		mutex_lock(&priv->plat->est->lock);
83 		priv->plat->est->enable = false;
84 		stmmac_est_configure(priv, priv->ioaddr, priv->plat->est,
85 				     priv->plat->clk_ptp_rate);
86 		mutex_unlock(&priv->plat->est->lock);
87 	}
88 
89 	spin_lock_irqsave(&priv->ptp_lock, flags);
90 	stmmac_adjust_systime(priv, priv->ptpaddr, sec, nsec, neg_adj, xmac);
91 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
92 
93 	/* Caculate new basetime and re-configured EST after PTP time adjust. */
94 	if (est_rst) {
95 		struct timespec64 current_time, time;
96 		ktime_t current_time_ns, basetime;
97 		u64 cycle_time;
98 
99 		mutex_lock(&priv->plat->est->lock);
100 		priv->ptp_clock_ops.gettime64(&priv->ptp_clock_ops, &current_time);
101 		current_time_ns = timespec64_to_ktime(current_time);
102 		time.tv_nsec = priv->plat->est->btr_reserve[0];
103 		time.tv_sec = priv->plat->est->btr_reserve[1];
104 		basetime = timespec64_to_ktime(time);
105 		cycle_time = (u64)priv->plat->est->ctr[1] * NSEC_PER_SEC +
106 			     priv->plat->est->ctr[0];
107 		time = stmmac_calc_tas_basetime(basetime,
108 						current_time_ns,
109 						cycle_time);
110 
111 		priv->plat->est->btr[0] = (u32)time.tv_nsec;
112 		priv->plat->est->btr[1] = (u32)time.tv_sec;
113 		priv->plat->est->enable = true;
114 		ret = stmmac_est_configure(priv, priv->ioaddr, priv->plat->est,
115 					   priv->plat->clk_ptp_rate);
116 		mutex_unlock(&priv->plat->est->lock);
117 		if (ret)
118 			netdev_err(priv->dev, "failed to configure EST\n");
119 	}
120 
121 	return 0;
122 }
123 
124 /**
125  * stmmac_get_time
126  *
127  * @ptp: pointer to ptp_clock_info structure
128  * @ts: pointer to hold time/result
129  *
130  * Description: this function will read the current time from the
131  * hardware clock and store it in @ts.
132  */
133 static int stmmac_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts)
134 {
135 	struct stmmac_priv *priv =
136 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
137 	unsigned long flags;
138 	u64 ns = 0;
139 
140 	spin_lock_irqsave(&priv->ptp_lock, flags);
141 	stmmac_get_systime(priv, priv->ptpaddr, &ns);
142 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
143 
144 	*ts = ns_to_timespec64(ns);
145 
146 	return 0;
147 }
148 
149 /**
150  * stmmac_set_time
151  *
152  * @ptp: pointer to ptp_clock_info structure
153  * @ts: time value to set
154  *
155  * Description: this function will set the current time on the
156  * hardware clock.
157  */
158 static int stmmac_set_time(struct ptp_clock_info *ptp,
159 			   const struct timespec64 *ts)
160 {
161 	struct stmmac_priv *priv =
162 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
163 	unsigned long flags;
164 
165 	spin_lock_irqsave(&priv->ptp_lock, flags);
166 	stmmac_init_systime(priv, priv->ptpaddr, ts->tv_sec, ts->tv_nsec);
167 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
168 
169 	return 0;
170 }
171 
172 static int stmmac_enable(struct ptp_clock_info *ptp,
173 			 struct ptp_clock_request *rq, int on)
174 {
175 	struct stmmac_priv *priv =
176 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
177 	void __iomem *ptpaddr = priv->ptpaddr;
178 	void __iomem *ioaddr = priv->hw->pcsr;
179 	struct stmmac_pps_cfg *cfg;
180 	u32 intr_value, acr_value;
181 	int ret = -EOPNOTSUPP;
182 	unsigned long flags;
183 
184 	switch (rq->type) {
185 	case PTP_CLK_REQ_PEROUT:
186 		/* Reject requests with unsupported flags */
187 		if (rq->perout.flags)
188 			return -EOPNOTSUPP;
189 
190 		cfg = &priv->pps[rq->perout.index];
191 
192 		cfg->start.tv_sec = rq->perout.start.sec;
193 		cfg->start.tv_nsec = rq->perout.start.nsec;
194 		cfg->period.tv_sec = rq->perout.period.sec;
195 		cfg->period.tv_nsec = rq->perout.period.nsec;
196 
197 		spin_lock_irqsave(&priv->ptp_lock, flags);
198 		ret = stmmac_flex_pps_config(priv, priv->ioaddr,
199 					     rq->perout.index, cfg, on,
200 					     priv->sub_second_inc,
201 					     priv->systime_flags);
202 		spin_unlock_irqrestore(&priv->ptp_lock, flags);
203 		break;
204 	case PTP_CLK_REQ_EXTTS:
205 		priv->plat->ext_snapshot_en = on;
206 		mutex_lock(&priv->aux_ts_lock);
207 		acr_value = readl(ptpaddr + PTP_ACR);
208 		acr_value &= ~PTP_ACR_MASK;
209 		if (on) {
210 			/* Enable External snapshot trigger */
211 			acr_value |= priv->plat->ext_snapshot_num;
212 			acr_value |= PTP_ACR_ATSFC;
213 			netdev_dbg(priv->dev, "Auxiliary Snapshot %d enabled.\n",
214 				   priv->plat->ext_snapshot_num >>
215 				   PTP_ACR_ATSEN_SHIFT);
216 			/* Enable Timestamp Interrupt */
217 			intr_value = readl(ioaddr + GMAC_INT_EN);
218 			intr_value |= GMAC_INT_TSIE;
219 			writel(intr_value, ioaddr + GMAC_INT_EN);
220 
221 		} else {
222 			netdev_dbg(priv->dev, "Auxiliary Snapshot %d disabled.\n",
223 				   priv->plat->ext_snapshot_num >>
224 				   PTP_ACR_ATSEN_SHIFT);
225 			/* Disable Timestamp Interrupt */
226 			intr_value = readl(ioaddr + GMAC_INT_EN);
227 			intr_value &= ~GMAC_INT_TSIE;
228 			writel(intr_value, ioaddr + GMAC_INT_EN);
229 		}
230 		writel(acr_value, ptpaddr + PTP_ACR);
231 		mutex_unlock(&priv->aux_ts_lock);
232 		ret = 0;
233 		break;
234 
235 	default:
236 		break;
237 	}
238 
239 	return ret;
240 }
241 
242 /**
243  * stmmac_get_syncdevicetime
244  * @device: current device time
245  * @system: system counter value read synchronously with device time
246  * @ctx: context provided by timekeeping code
247  * Description: Read device and system clock simultaneously and return the
248  * corrected clock values in ns.
249  **/
250 static int stmmac_get_syncdevicetime(ktime_t *device,
251 				     struct system_counterval_t *system,
252 				     void *ctx)
253 {
254 	struct stmmac_priv *priv = (struct stmmac_priv *)ctx;
255 
256 	if (priv->plat->crosststamp)
257 		return priv->plat->crosststamp(device, system, ctx);
258 	else
259 		return -EOPNOTSUPP;
260 }
261 
262 static int stmmac_getcrosststamp(struct ptp_clock_info *ptp,
263 				 struct system_device_crosststamp *xtstamp)
264 {
265 	struct stmmac_priv *priv =
266 		container_of(ptp, struct stmmac_priv, ptp_clock_ops);
267 
268 	return get_device_system_crosststamp(stmmac_get_syncdevicetime,
269 					     priv, NULL, xtstamp);
270 }
271 
272 /* structure describing a PTP hardware clock */
273 static struct ptp_clock_info stmmac_ptp_clock_ops = {
274 	.owner = THIS_MODULE,
275 	.name = "stmmac ptp",
276 	.max_adj = 62500000,
277 	.n_alarm = 0,
278 	.n_ext_ts = 0, /* will be overwritten in stmmac_ptp_register */
279 	.n_per_out = 0, /* will be overwritten in stmmac_ptp_register */
280 	.n_pins = 0,
281 	.pps = 0,
282 	.adjfreq = stmmac_adjust_freq,
283 	.adjtime = stmmac_adjust_time,
284 	.gettime64 = stmmac_get_time,
285 	.settime64 = stmmac_set_time,
286 	.enable = stmmac_enable,
287 	.getcrosststamp = stmmac_getcrosststamp,
288 };
289 
290 /**
291  * stmmac_ptp_register
292  * @priv: driver private structure
293  * Description: this function will register the ptp clock driver
294  * to kernel. It also does some house keeping work.
295  */
296 void stmmac_ptp_register(struct stmmac_priv *priv)
297 {
298 	int i;
299 
300 	for (i = 0; i < priv->dma_cap.pps_out_num; i++) {
301 		if (i >= STMMAC_PPS_MAX)
302 			break;
303 		priv->pps[i].available = true;
304 	}
305 
306 	if (priv->plat->ptp_max_adj)
307 		stmmac_ptp_clock_ops.max_adj = priv->plat->ptp_max_adj;
308 
309 	/* Calculate the clock domain crossing (CDC) error if necessary */
310 	priv->plat->cdc_error_adj = 0;
311 	if (priv->plat->has_gmac4 && priv->plat->clk_ptp_rate)
312 		priv->plat->cdc_error_adj = (2 * NSEC_PER_SEC) / priv->plat->clk_ptp_rate;
313 
314 	stmmac_ptp_clock_ops.n_per_out = priv->dma_cap.pps_out_num;
315 	stmmac_ptp_clock_ops.n_ext_ts = priv->dma_cap.aux_snapshot_n;
316 
317 	spin_lock_init(&priv->ptp_lock);
318 	mutex_init(&priv->aux_ts_lock);
319 	priv->ptp_clock_ops = stmmac_ptp_clock_ops;
320 
321 	priv->ptp_clock = ptp_clock_register(&priv->ptp_clock_ops,
322 					     priv->device);
323 	if (IS_ERR(priv->ptp_clock)) {
324 		netdev_err(priv->dev, "ptp_clock_register failed\n");
325 		priv->ptp_clock = NULL;
326 	} else if (priv->ptp_clock)
327 		netdev_info(priv->dev, "registered PTP clock\n");
328 }
329 
330 /**
331  * stmmac_ptp_unregister
332  * @priv: driver private structure
333  * Description: this function will remove/unregister the ptp clock driver
334  * from the kernel.
335  */
336 void stmmac_ptp_unregister(struct stmmac_priv *priv)
337 {
338 	if (priv->ptp_clock) {
339 		ptp_clock_unregister(priv->ptp_clock);
340 		priv->ptp_clock = NULL;
341 		pr_debug("Removed PTP HW clock successfully on %s\n",
342 			 priv->dev->name);
343 	}
344 
345 	mutex_destroy(&priv->aux_ts_lock);
346 }
347