xref: /openbmc/linux/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c (revision 023e41632e065d49bcbe31b3c4b336217f96a271)
1 /*******************************************************************************
2   PTP 1588 clock using the STMMAC.
3 
4   Copyright (C) 2013  Vayavya Labs Pvt Ltd
5 
6   This program is free software; you can redistribute it and/or modify it
7   under the terms and conditions of the GNU General Public License,
8   version 2, as published by the Free Software Foundation.
9 
10   This program is distributed in the hope it will be useful, but WITHOUT
11   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13   more details.
14 
15   The full GNU General Public License is included in this distribution in
16   the file called "COPYING".
17 
18   Author: Rayagond Kokatanur <rayagond@vayavyalabs.com>
19 *******************************************************************************/
20 #include "stmmac.h"
21 #include "stmmac_ptp.h"
22 
23 /**
24  * stmmac_adjust_freq
25  *
26  * @ptp: pointer to ptp_clock_info structure
27  * @ppb: desired period change in parts ber billion
28  *
29  * Description: this function will adjust the frequency of hardware clock.
30  */
31 static int stmmac_adjust_freq(struct ptp_clock_info *ptp, s32 ppb)
32 {
33 	struct stmmac_priv *priv =
34 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
35 	unsigned long flags;
36 	u32 diff, addend;
37 	int neg_adj = 0;
38 	u64 adj;
39 
40 	if (ppb < 0) {
41 		neg_adj = 1;
42 		ppb = -ppb;
43 	}
44 
45 	addend = priv->default_addend;
46 	adj = addend;
47 	adj *= ppb;
48 	diff = div_u64(adj, 1000000000ULL);
49 	addend = neg_adj ? (addend - diff) : (addend + diff);
50 
51 	spin_lock_irqsave(&priv->ptp_lock, flags);
52 	stmmac_config_addend(priv, priv->ptpaddr, addend);
53 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
54 
55 	return 0;
56 }
57 
58 /**
59  * stmmac_adjust_time
60  *
61  * @ptp: pointer to ptp_clock_info structure
62  * @delta: desired change in nanoseconds
63  *
64  * Description: this function will shift/adjust the hardware clock time.
65  */
66 static int stmmac_adjust_time(struct ptp_clock_info *ptp, s64 delta)
67 {
68 	struct stmmac_priv *priv =
69 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
70 	unsigned long flags;
71 	u32 sec, nsec;
72 	u32 quotient, reminder;
73 	int neg_adj = 0;
74 	bool xmac;
75 
76 	xmac = priv->plat->has_gmac4 || priv->plat->has_xgmac;
77 
78 	if (delta < 0) {
79 		neg_adj = 1;
80 		delta = -delta;
81 	}
82 
83 	quotient = div_u64_rem(delta, 1000000000ULL, &reminder);
84 	sec = quotient;
85 	nsec = reminder;
86 
87 	spin_lock_irqsave(&priv->ptp_lock, flags);
88 	stmmac_adjust_systime(priv, priv->ptpaddr, sec, nsec, neg_adj, xmac);
89 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
90 
91 	return 0;
92 }
93 
94 /**
95  * stmmac_get_time
96  *
97  * @ptp: pointer to ptp_clock_info structure
98  * @ts: pointer to hold time/result
99  *
100  * Description: this function will read the current time from the
101  * hardware clock and store it in @ts.
102  */
103 static int stmmac_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts)
104 {
105 	struct stmmac_priv *priv =
106 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
107 	unsigned long flags;
108 	u64 ns = 0;
109 
110 	spin_lock_irqsave(&priv->ptp_lock, flags);
111 	stmmac_get_systime(priv, priv->ptpaddr, &ns);
112 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
113 
114 	*ts = ns_to_timespec64(ns);
115 
116 	return 0;
117 }
118 
119 /**
120  * stmmac_set_time
121  *
122  * @ptp: pointer to ptp_clock_info structure
123  * @ts: time value to set
124  *
125  * Description: this function will set the current time on the
126  * hardware clock.
127  */
128 static int stmmac_set_time(struct ptp_clock_info *ptp,
129 			   const struct timespec64 *ts)
130 {
131 	struct stmmac_priv *priv =
132 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
133 	unsigned long flags;
134 
135 	spin_lock_irqsave(&priv->ptp_lock, flags);
136 	stmmac_init_systime(priv, priv->ptpaddr, ts->tv_sec, ts->tv_nsec);
137 	spin_unlock_irqrestore(&priv->ptp_lock, flags);
138 
139 	return 0;
140 }
141 
142 static int stmmac_enable(struct ptp_clock_info *ptp,
143 			 struct ptp_clock_request *rq, int on)
144 {
145 	struct stmmac_priv *priv =
146 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
147 	struct stmmac_pps_cfg *cfg;
148 	int ret = -EOPNOTSUPP;
149 	unsigned long flags;
150 
151 	switch (rq->type) {
152 	case PTP_CLK_REQ_PEROUT:
153 		cfg = &priv->pps[rq->perout.index];
154 
155 		cfg->start.tv_sec = rq->perout.start.sec;
156 		cfg->start.tv_nsec = rq->perout.start.nsec;
157 		cfg->period.tv_sec = rq->perout.period.sec;
158 		cfg->period.tv_nsec = rq->perout.period.nsec;
159 
160 		spin_lock_irqsave(&priv->ptp_lock, flags);
161 		ret = stmmac_flex_pps_config(priv, priv->ioaddr,
162 					     rq->perout.index, cfg, on,
163 					     priv->sub_second_inc,
164 					     priv->systime_flags);
165 		spin_unlock_irqrestore(&priv->ptp_lock, flags);
166 		break;
167 	default:
168 		break;
169 	}
170 
171 	return ret;
172 }
173 
174 /* structure describing a PTP hardware clock */
175 static struct ptp_clock_info stmmac_ptp_clock_ops = {
176 	.owner = THIS_MODULE,
177 	.name = "stmmac_ptp_clock",
178 	.max_adj = 62500000,
179 	.n_alarm = 0,
180 	.n_ext_ts = 0,
181 	.n_per_out = 0, /* will be overwritten in stmmac_ptp_register */
182 	.n_pins = 0,
183 	.pps = 0,
184 	.adjfreq = stmmac_adjust_freq,
185 	.adjtime = stmmac_adjust_time,
186 	.gettime64 = stmmac_get_time,
187 	.settime64 = stmmac_set_time,
188 	.enable = stmmac_enable,
189 };
190 
191 /**
192  * stmmac_ptp_register
193  * @priv: driver private structure
194  * Description: this function will register the ptp clock driver
195  * to kernel. It also does some house keeping work.
196  */
197 void stmmac_ptp_register(struct stmmac_priv *priv)
198 {
199 	int i;
200 
201 	for (i = 0; i < priv->dma_cap.pps_out_num; i++) {
202 		if (i >= STMMAC_PPS_MAX)
203 			break;
204 		priv->pps[i].available = true;
205 	}
206 
207 	stmmac_ptp_clock_ops.n_per_out = priv->dma_cap.pps_out_num;
208 
209 	spin_lock_init(&priv->ptp_lock);
210 	priv->ptp_clock_ops = stmmac_ptp_clock_ops;
211 
212 	priv->ptp_clock = ptp_clock_register(&priv->ptp_clock_ops,
213 					     priv->device);
214 	if (IS_ERR(priv->ptp_clock)) {
215 		netdev_err(priv->dev, "ptp_clock_register failed\n");
216 		priv->ptp_clock = NULL;
217 	} else if (priv->ptp_clock)
218 		netdev_info(priv->dev, "registered PTP clock\n");
219 }
220 
221 /**
222  * stmmac_ptp_unregister
223  * @priv: driver private structure
224  * Description: this function will remove/unregister the ptp clock driver
225  * from the kernel.
226  */
227 void stmmac_ptp_unregister(struct stmmac_priv *priv)
228 {
229 	if (priv->ptp_clock) {
230 		ptp_clock_unregister(priv->ptp_clock);
231 		priv->ptp_clock = NULL;
232 		pr_debug("Removed PTP HW clock successfully on %s\n",
233 			 priv->dev->name);
234 	}
235 }
236