xref: /openbmc/linux/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c (revision 8b0adbe3e38dbe5aae9edf6f5159ffdca7cfbdf1)
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;
66 
67 	xmac = priv->plat->has_gmac4 || priv->plat->has_xgmac;
68 
69 	if (delta < 0) {
70 		neg_adj = 1;
71 		delta = -delta;
72 	}
73 
74 	quotient = div_u64_rem(delta, 1000000000ULL, &reminder);
75 	sec = quotient;
76 	nsec = reminder;
77 
78 	spin_lock_irqsave(&priv->ptp_lock, flags);
79 	stmmac_adjust_systime(priv, priv->ptpaddr, sec, nsec, neg_adj, xmac);
80 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
81 
82 	return 0;
83 }
84 
85 /**
86  * stmmac_get_time
87  *
88  * @ptp: pointer to ptp_clock_info structure
89  * @ts: pointer to hold time/result
90  *
91  * Description: this function will read the current time from the
92  * hardware clock and store it in @ts.
93  */
94 static int stmmac_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts)
95 {
96 	struct stmmac_priv *priv =
97 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
98 	unsigned long flags;
99 	u64 ns = 0;
100 
101 	spin_lock_irqsave(&priv->ptp_lock, flags);
102 	stmmac_get_systime(priv, priv->ptpaddr, &ns);
103 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
104 
105 	*ts = ns_to_timespec64(ns);
106 
107 	return 0;
108 }
109 
110 /**
111  * stmmac_set_time
112  *
113  * @ptp: pointer to ptp_clock_info structure
114  * @ts: time value to set
115  *
116  * Description: this function will set the current time on the
117  * hardware clock.
118  */
119 static int stmmac_set_time(struct ptp_clock_info *ptp,
120 			   const struct timespec64 *ts)
121 {
122 	struct stmmac_priv *priv =
123 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
124 	unsigned long flags;
125 
126 	spin_lock_irqsave(&priv->ptp_lock, flags);
127 	stmmac_init_systime(priv, priv->ptpaddr, ts->tv_sec, ts->tv_nsec);
128 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
129 
130 	return 0;
131 }
132 
133 static int stmmac_enable(struct ptp_clock_info *ptp,
134 			 struct ptp_clock_request *rq, int on)
135 {
136 	struct stmmac_priv *priv =
137 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
138 	struct stmmac_pps_cfg *cfg;
139 	int ret = -EOPNOTSUPP;
140 	unsigned long flags;
141 
142 	switch (rq->type) {
143 	case PTP_CLK_REQ_PEROUT:
144 		/* Reject requests with unsupported flags */
145 		if (rq->perout.flags)
146 			return -EOPNOTSUPP;
147 
148 		cfg = &priv->pps[rq->perout.index];
149 
150 		cfg->start.tv_sec = rq->perout.start.sec;
151 		cfg->start.tv_nsec = rq->perout.start.nsec;
152 		cfg->period.tv_sec = rq->perout.period.sec;
153 		cfg->period.tv_nsec = rq->perout.period.nsec;
154 
155 		spin_lock_irqsave(&priv->ptp_lock, flags);
156 		ret = stmmac_flex_pps_config(priv, priv->ioaddr,
157 					     rq->perout.index, cfg, on,
158 					     priv->sub_second_inc,
159 					     priv->systime_flags);
160 		spin_unlock_irqrestore(&priv->ptp_lock, flags);
161 		break;
162 	default:
163 		break;
164 	}
165 
166 	return ret;
167 }
168 
169 /**
170  * stmmac_get_syncdevicetime
171  * @device: current device time
172  * @system: system counter value read synchronously with device time
173  * @ctx: context provided by timekeeping code
174  * Description: Read device and system clock simultaneously and return the
175  * corrected clock values in ns.
176  **/
177 static int stmmac_get_syncdevicetime(ktime_t *device,
178 				     struct system_counterval_t *system,
179 				     void *ctx)
180 {
181 	struct stmmac_priv *priv = (struct stmmac_priv *)ctx;
182 
183 	if (priv->plat->crosststamp)
184 		return priv->plat->crosststamp(device, system, ctx);
185 	else
186 		return -EOPNOTSUPP;
187 }
188 
189 static int stmmac_getcrosststamp(struct ptp_clock_info *ptp,
190 				 struct system_device_crosststamp *xtstamp)
191 {
192 	struct stmmac_priv *priv =
193 		container_of(ptp, struct stmmac_priv, ptp_clock_ops);
194 
195 	return get_device_system_crosststamp(stmmac_get_syncdevicetime,
196 					     priv, NULL, xtstamp);
197 }
198 
199 /* structure describing a PTP hardware clock */
200 static struct ptp_clock_info stmmac_ptp_clock_ops = {
201 	.owner = THIS_MODULE,
202 	.name = "stmmac ptp",
203 	.max_adj = 62500000,
204 	.n_alarm = 0,
205 	.n_ext_ts = 0,
206 	.n_per_out = 0, /* will be overwritten in stmmac_ptp_register */
207 	.n_pins = 0,
208 	.pps = 0,
209 	.adjfreq = stmmac_adjust_freq,
210 	.adjtime = stmmac_adjust_time,
211 	.gettime64 = stmmac_get_time,
212 	.settime64 = stmmac_set_time,
213 	.enable = stmmac_enable,
214 	.getcrosststamp = stmmac_getcrosststamp,
215 };
216 
217 /**
218  * stmmac_ptp_register
219  * @priv: driver private structure
220  * Description: this function will register the ptp clock driver
221  * to kernel. It also does some house keeping work.
222  */
223 void stmmac_ptp_register(struct stmmac_priv *priv)
224 {
225 	int i;
226 
227 	if (priv->plat->ptp_clk_freq_config)
228 		priv->plat->ptp_clk_freq_config(priv);
229 
230 	for (i = 0; i < priv->dma_cap.pps_out_num; i++) {
231 		if (i >= STMMAC_PPS_MAX)
232 			break;
233 		priv->pps[i].available = true;
234 	}
235 
236 	if (priv->plat->ptp_max_adj)
237 		stmmac_ptp_clock_ops.max_adj = priv->plat->ptp_max_adj;
238 
239 	stmmac_ptp_clock_ops.n_per_out = priv->dma_cap.pps_out_num;
240 
241 	spin_lock_init(&priv->ptp_lock);
242 	priv->ptp_clock_ops = stmmac_ptp_clock_ops;
243 
244 	priv->ptp_clock = ptp_clock_register(&priv->ptp_clock_ops,
245 					     priv->device);
246 	if (IS_ERR(priv->ptp_clock)) {
247 		netdev_err(priv->dev, "ptp_clock_register failed\n");
248 		priv->ptp_clock = NULL;
249 	} else if (priv->ptp_clock)
250 		netdev_info(priv->dev, "registered PTP clock\n");
251 }
252 
253 /**
254  * stmmac_ptp_unregister
255  * @priv: driver private structure
256  * Description: this function will remove/unregister the ptp clock driver
257  * from the kernel.
258  */
259 void stmmac_ptp_unregister(struct stmmac_priv *priv)
260 {
261 	if (priv->ptp_clock) {
262 		ptp_clock_unregister(priv->ptp_clock);
263 		priv->ptp_clock = NULL;
264 		pr_debug("Removed PTP HW clock successfully on %s\n",
265 			 priv->dev->name);
266 	}
267 }
268