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 */
21static 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 */
56static 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 */
93static 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 */
118static 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
132static 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 */
169static 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 */
191void 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 */
224void 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