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  * @ppb: desired period change in parts ber billion
18  *
19  * Description: this function will adjust the frequency of hardware clock.
20  */
21 static int stmmac_adjust_freq(struct ptp_clock_info *ptp, s32 ppb)
22 {
23 	struct stmmac_priv *priv =
24 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
25 	unsigned long flags;
26 	u32 diff, addend;
27 	int neg_adj = 0;
28 	u64 adj;
29 
30 	if (ppb < 0) {
31 		neg_adj = 1;
32 		ppb = -ppb;
33 	}
34 
35 	addend = priv->default_addend;
36 	adj = addend;
37 	adj *= ppb;
38 	diff = div_u64(adj, 1000000000ULL);
39 	addend = neg_adj ? (addend - diff) : (addend + diff);
40 
41 	spin_lock_irqsave(&priv->ptp_lock, flags);
42 	stmmac_config_addend(priv, priv->ptpaddr, addend);
43 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
44 
45 	return 0;
46 }
47 
48 /**
49  * stmmac_adjust_time
50  *
51  * @ptp: pointer to ptp_clock_info structure
52  * @delta: desired change in nanoseconds
53  *
54  * Description: this function will shift/adjust the hardware clock time.
55  */
56 static int stmmac_adjust_time(struct ptp_clock_info *ptp, s64 delta)
57 {
58 	struct stmmac_priv *priv =
59 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
60 	unsigned long flags;
61 	u32 sec, nsec;
62 	u32 quotient, reminder;
63 	int neg_adj = 0;
64 	bool xmac;
65 
66 	xmac = priv->plat->has_gmac4 || priv->plat->has_xgmac;
67 
68 	if (delta < 0) {
69 		neg_adj = 1;
70 		delta = -delta;
71 	}
72 
73 	quotient = div_u64_rem(delta, 1000000000ULL, &reminder);
74 	sec = quotient;
75 	nsec = reminder;
76 
77 	spin_lock_irqsave(&priv->ptp_lock, flags);
78 	stmmac_adjust_systime(priv, priv->ptpaddr, sec, nsec, neg_adj, xmac);
79 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
80 
81 	return 0;
82 }
83 
84 /**
85  * stmmac_get_time
86  *
87  * @ptp: pointer to ptp_clock_info structure
88  * @ts: pointer to hold time/result
89  *
90  * Description: this function will read the current time from the
91  * hardware clock and store it in @ts.
92  */
93 static int stmmac_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts)
94 {
95 	struct stmmac_priv *priv =
96 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
97 	unsigned long flags;
98 	u64 ns = 0;
99 
100 	spin_lock_irqsave(&priv->ptp_lock, flags);
101 	stmmac_get_systime(priv, priv->ptpaddr, &ns);
102 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
103 
104 	*ts = ns_to_timespec64(ns);
105 
106 	return 0;
107 }
108 
109 /**
110  * stmmac_set_time
111  *
112  * @ptp: pointer to ptp_clock_info structure
113  * @ts: time value to set
114  *
115  * Description: this function will set the current time on the
116  * hardware clock.
117  */
118 static int stmmac_set_time(struct ptp_clock_info *ptp,
119 			   const struct timespec64 *ts)
120 {
121 	struct stmmac_priv *priv =
122 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
123 	unsigned long flags;
124 
125 	spin_lock_irqsave(&priv->ptp_lock, flags);
126 	stmmac_init_systime(priv, priv->ptpaddr, ts->tv_sec, ts->tv_nsec);
127 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
128 
129 	return 0;
130 }
131 
132 static int stmmac_enable(struct ptp_clock_info *ptp,
133 			 struct ptp_clock_request *rq, int on)
134 {
135 	struct stmmac_priv *priv =
136 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
137 	struct stmmac_pps_cfg *cfg;
138 	int ret = -EOPNOTSUPP;
139 	unsigned long flags;
140 
141 	switch (rq->type) {
142 	case PTP_CLK_REQ_PEROUT:
143 		/* Reject requests with unsupported flags */
144 		if (rq->perout.flags)
145 			return -EOPNOTSUPP;
146 
147 		cfg = &priv->pps[rq->perout.index];
148 
149 		cfg->start.tv_sec = rq->perout.start.sec;
150 		cfg->start.tv_nsec = rq->perout.start.nsec;
151 		cfg->period.tv_sec = rq->perout.period.sec;
152 		cfg->period.tv_nsec = rq->perout.period.nsec;
153 
154 		spin_lock_irqsave(&priv->ptp_lock, flags);
155 		ret = stmmac_flex_pps_config(priv, priv->ioaddr,
156 					     rq->perout.index, cfg, on,
157 					     priv->sub_second_inc,
158 					     priv->systime_flags);
159 		spin_unlock_irqrestore(&priv->ptp_lock, flags);
160 		break;
161 	default:
162 		break;
163 	}
164 
165 	return ret;
166 }
167 
168 /* structure describing a PTP hardware clock */
169 static struct ptp_clock_info stmmac_ptp_clock_ops = {
170 	.owner = THIS_MODULE,
171 	.name = "stmmac ptp",
172 	.max_adj = 62500000,
173 	.n_alarm = 0,
174 	.n_ext_ts = 0,
175 	.n_per_out = 0, /* will be overwritten in stmmac_ptp_register */
176 	.n_pins = 0,
177 	.pps = 0,
178 	.adjfreq = stmmac_adjust_freq,
179 	.adjtime = stmmac_adjust_time,
180 	.gettime64 = stmmac_get_time,
181 	.settime64 = stmmac_set_time,
182 	.enable = stmmac_enable,
183 };
184 
185 /**
186  * stmmac_ptp_register
187  * @priv: driver private structure
188  * Description: this function will register the ptp clock driver
189  * to kernel. It also does some house keeping work.
190  */
191 void stmmac_ptp_register(struct stmmac_priv *priv)
192 {
193 	int i;
194 
195 	for (i = 0; i < priv->dma_cap.pps_out_num; i++) {
196 		if (i >= STMMAC_PPS_MAX)
197 			break;
198 		priv->pps[i].available = true;
199 	}
200 
201 	if (priv->plat->ptp_max_adj)
202 		stmmac_ptp_clock_ops.max_adj = priv->plat->ptp_max_adj;
203 
204 	stmmac_ptp_clock_ops.n_per_out = priv->dma_cap.pps_out_num;
205 
206 	spin_lock_init(&priv->ptp_lock);
207 	priv->ptp_clock_ops = stmmac_ptp_clock_ops;
208 
209 	priv->ptp_clock = ptp_clock_register(&priv->ptp_clock_ops,
210 					     priv->device);
211 	if (IS_ERR(priv->ptp_clock)) {
212 		netdev_err(priv->dev, "ptp_clock_register failed\n");
213 		priv->ptp_clock = NULL;
214 	} else if (priv->ptp_clock)
215 		netdev_info(priv->dev, "registered PTP clock\n");
216 }
217 
218 /**
219  * stmmac_ptp_unregister
220  * @priv: driver private structure
221  * Description: this function will remove/unregister the ptp clock driver
222  * from the kernel.
223  */
224 void stmmac_ptp_unregister(struct stmmac_priv *priv)
225 {
226 	if (priv->ptp_clock) {
227 		ptp_clock_unregister(priv->ptp_clock);
228 		priv->ptp_clock = NULL;
229 		pr_debug("Removed PTP HW clock successfully on %s\n",
230 			 priv->dev->name);
231 	}
232 }
233