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 * @scaled_ppm: desired period change in scaled parts per million
19 *
20 * Description: this function will adjust the frequency of hardware clock.
21 *
22 * Scaled parts per million is ppm with a 16-bit binary fractional field.
23 */
24static int stmmac_adjust_freq(struct ptp_clock_info *ptp, long scaled_ppm)
25{
26	struct stmmac_priv *priv =
27	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
28	unsigned long flags;
29	u32 addend;
30
31	addend = adjust_by_scaled_ppm(priv->default_addend, scaled_ppm);
32
33	write_lock_irqsave(&priv->ptp_lock, flags);
34	stmmac_config_addend(priv, priv->ptpaddr, addend);
35	write_unlock_irqrestore(&priv->ptp_lock, flags);
36
37	return 0;
38}
39
40/**
41 * stmmac_adjust_time
42 *
43 * @ptp: pointer to ptp_clock_info structure
44 * @delta: desired change in nanoseconds
45 *
46 * Description: this function will shift/adjust the hardware clock time.
47 */
48static int stmmac_adjust_time(struct ptp_clock_info *ptp, s64 delta)
49{
50	struct stmmac_priv *priv =
51	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
52	unsigned long flags;
53	u32 sec, nsec;
54	u32 quotient, reminder;
55	int neg_adj = 0;
56	bool xmac, est_rst = false;
57	int ret;
58
59	xmac = priv->plat->has_gmac4 || priv->plat->has_xgmac;
60
61	if (delta < 0) {
62		neg_adj = 1;
63		delta = -delta;
64	}
65
66	quotient = div_u64_rem(delta, 1000000000ULL, &reminder);
67	sec = quotient;
68	nsec = reminder;
69
70	/* If EST is enabled, disabled it before adjust ptp time. */
71	if (priv->plat->est && priv->plat->est->enable) {
72		est_rst = true;
73		mutex_lock(&priv->plat->est->lock);
74		priv->plat->est->enable = false;
75		stmmac_est_configure(priv, priv, priv->plat->est,
76				     priv->plat->clk_ptp_rate);
77		mutex_unlock(&priv->plat->est->lock);
78	}
79
80	write_lock_irqsave(&priv->ptp_lock, flags);
81	stmmac_adjust_systime(priv, priv->ptpaddr, sec, nsec, neg_adj, xmac);
82	write_unlock_irqrestore(&priv->ptp_lock, flags);
83
84	/* Calculate new basetime and re-configured EST after PTP time adjust. */
85	if (est_rst) {
86		struct timespec64 current_time, time;
87		ktime_t current_time_ns, basetime;
88		u64 cycle_time;
89
90		mutex_lock(&priv->plat->est->lock);
91		priv->ptp_clock_ops.gettime64(&priv->ptp_clock_ops, &current_time);
92		current_time_ns = timespec64_to_ktime(current_time);
93		time.tv_nsec = priv->plat->est->btr_reserve[0];
94		time.tv_sec = priv->plat->est->btr_reserve[1];
95		basetime = timespec64_to_ktime(time);
96		cycle_time = (u64)priv->plat->est->ctr[1] * NSEC_PER_SEC +
97			     priv->plat->est->ctr[0];
98		time = stmmac_calc_tas_basetime(basetime,
99						current_time_ns,
100						cycle_time);
101
102		priv->plat->est->btr[0] = (u32)time.tv_nsec;
103		priv->plat->est->btr[1] = (u32)time.tv_sec;
104		priv->plat->est->enable = true;
105		ret = stmmac_est_configure(priv, priv, priv->plat->est,
106					   priv->plat->clk_ptp_rate);
107		mutex_unlock(&priv->plat->est->lock);
108		if (ret)
109			netdev_err(priv->dev, "failed to configure EST\n");
110	}
111
112	return 0;
113}
114
115/**
116 * stmmac_get_time
117 *
118 * @ptp: pointer to ptp_clock_info structure
119 * @ts: pointer to hold time/result
120 *
121 * Description: this function will read the current time from the
122 * hardware clock and store it in @ts.
123 */
124static int stmmac_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts)
125{
126	struct stmmac_priv *priv =
127	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
128	unsigned long flags;
129	u64 ns = 0;
130
131	read_lock_irqsave(&priv->ptp_lock, flags);
132	stmmac_get_systime(priv, priv->ptpaddr, &ns);
133	read_unlock_irqrestore(&priv->ptp_lock, flags);
134
135	*ts = ns_to_timespec64(ns);
136
137	return 0;
138}
139
140/**
141 * stmmac_set_time
142 *
143 * @ptp: pointer to ptp_clock_info structure
144 * @ts: time value to set
145 *
146 * Description: this function will set the current time on the
147 * hardware clock.
148 */
149static int stmmac_set_time(struct ptp_clock_info *ptp,
150			   const struct timespec64 *ts)
151{
152	struct stmmac_priv *priv =
153	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
154	unsigned long flags;
155
156	write_lock_irqsave(&priv->ptp_lock, flags);
157	stmmac_init_systime(priv, priv->ptpaddr, ts->tv_sec, ts->tv_nsec);
158	write_unlock_irqrestore(&priv->ptp_lock, flags);
159
160	return 0;
161}
162
163static int stmmac_enable(struct ptp_clock_info *ptp,
164			 struct ptp_clock_request *rq, int on)
165{
166	struct stmmac_priv *priv =
167	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
168	void __iomem *ptpaddr = priv->ptpaddr;
169	struct stmmac_pps_cfg *cfg;
170	int ret = -EOPNOTSUPP;
171	unsigned long flags;
172	u32 acr_value;
173
174	switch (rq->type) {
175	case PTP_CLK_REQ_PEROUT:
176		/* Reject requests with unsupported flags */
177		if (rq->perout.flags)
178			return -EOPNOTSUPP;
179
180		cfg = &priv->pps[rq->perout.index];
181
182		cfg->start.tv_sec = rq->perout.start.sec;
183		cfg->start.tv_nsec = rq->perout.start.nsec;
184		cfg->period.tv_sec = rq->perout.period.sec;
185		cfg->period.tv_nsec = rq->perout.period.nsec;
186
187		write_lock_irqsave(&priv->ptp_lock, flags);
188		ret = stmmac_flex_pps_config(priv, priv->ioaddr,
189					     rq->perout.index, cfg, on,
190					     priv->sub_second_inc,
191					     priv->systime_flags);
192		write_unlock_irqrestore(&priv->ptp_lock, flags);
193		break;
194	case PTP_CLK_REQ_EXTTS: {
195		u8 channel;
196
197		mutex_lock(&priv->aux_ts_lock);
198		acr_value = readl(ptpaddr + PTP_ACR);
199		channel = ilog2(FIELD_GET(PTP_ACR_MASK, acr_value));
200		acr_value &= ~PTP_ACR_MASK;
201
202		if (on) {
203			if (FIELD_GET(PTP_ACR_MASK, acr_value)) {
204				netdev_err(priv->dev,
205					   "Cannot enable auxiliary snapshot %d as auxiliary snapshot %d is already enabled",
206					rq->extts.index, channel);
207				mutex_unlock(&priv->aux_ts_lock);
208				return -EBUSY;
209			}
210
211			priv->plat->flags |= STMMAC_FLAG_EXT_SNAPSHOT_EN;
212
213			/* Enable External snapshot trigger */
214			acr_value |= PTP_ACR_ATSEN(rq->extts.index);
215			acr_value |= PTP_ACR_ATSFC;
216		} else {
217			priv->plat->flags &= ~STMMAC_FLAG_EXT_SNAPSHOT_EN;
218		}
219		netdev_dbg(priv->dev, "Auxiliary Snapshot %d %s.\n",
220			   rq->extts.index, on ? "enabled" : "disabled");
221		writel(acr_value, ptpaddr + PTP_ACR);
222		mutex_unlock(&priv->aux_ts_lock);
223		/* wait for auxts fifo clear to finish */
224		ret = readl_poll_timeout(ptpaddr + PTP_ACR, acr_value,
225					 !(acr_value & PTP_ACR_ATSFC),
226					 10, 10000);
227		break;
228	}
229
230	default:
231		break;
232	}
233
234	return ret;
235}
236
237/**
238 * stmmac_get_syncdevicetime
239 * @device: current device time
240 * @system: system counter value read synchronously with device time
241 * @ctx: context provided by timekeeping code
242 * Description: Read device and system clock simultaneously and return the
243 * corrected clock values in ns.
244 **/
245static int stmmac_get_syncdevicetime(ktime_t *device,
246				     struct system_counterval_t *system,
247				     void *ctx)
248{
249	struct stmmac_priv *priv = (struct stmmac_priv *)ctx;
250
251	if (priv->plat->crosststamp)
252		return priv->plat->crosststamp(device, system, ctx);
253	else
254		return -EOPNOTSUPP;
255}
256
257static int stmmac_getcrosststamp(struct ptp_clock_info *ptp,
258				 struct system_device_crosststamp *xtstamp)
259{
260	struct stmmac_priv *priv =
261		container_of(ptp, struct stmmac_priv, ptp_clock_ops);
262
263	return get_device_system_crosststamp(stmmac_get_syncdevicetime,
264					     priv, NULL, xtstamp);
265}
266
267/* structure describing a PTP hardware clock */
268static struct ptp_clock_info stmmac_ptp_clock_ops = {
269	.owner = THIS_MODULE,
270	.name = "stmmac ptp",
271	.max_adj = 62500000,
272	.n_alarm = 0,
273	.n_ext_ts = 0, /* will be overwritten in stmmac_ptp_register */
274	.n_per_out = 0, /* will be overwritten in stmmac_ptp_register */
275	.n_pins = 0,
276	.pps = 0,
277	.adjfine = stmmac_adjust_freq,
278	.adjtime = stmmac_adjust_time,
279	.gettime64 = stmmac_get_time,
280	.settime64 = stmmac_set_time,
281	.enable = stmmac_enable,
282	.getcrosststamp = stmmac_getcrosststamp,
283};
284
285/**
286 * stmmac_ptp_register
287 * @priv: driver private structure
288 * Description: this function will register the ptp clock driver
289 * to kernel. It also does some house keeping work.
290 */
291void stmmac_ptp_register(struct stmmac_priv *priv)
292{
293	int i;
294
295	for (i = 0; i < priv->dma_cap.pps_out_num; i++) {
296		if (i >= STMMAC_PPS_MAX)
297			break;
298		priv->pps[i].available = true;
299	}
300
301	if (priv->plat->ptp_max_adj)
302		stmmac_ptp_clock_ops.max_adj = priv->plat->ptp_max_adj;
303
304	/* Calculate the clock domain crossing (CDC) error if necessary */
305	priv->plat->cdc_error_adj = 0;
306	if (priv->plat->has_gmac4 && priv->plat->clk_ptp_rate)
307		priv->plat->cdc_error_adj = (2 * NSEC_PER_SEC) / priv->plat->clk_ptp_rate;
308
309	stmmac_ptp_clock_ops.n_per_out = priv->dma_cap.pps_out_num;
310	stmmac_ptp_clock_ops.n_ext_ts = priv->dma_cap.aux_snapshot_n;
311
312	rwlock_init(&priv->ptp_lock);
313	mutex_init(&priv->aux_ts_lock);
314	priv->ptp_clock_ops = stmmac_ptp_clock_ops;
315
316	priv->ptp_clock = ptp_clock_register(&priv->ptp_clock_ops,
317					     priv->device);
318	if (IS_ERR(priv->ptp_clock)) {
319		netdev_err(priv->dev, "ptp_clock_register failed\n");
320		priv->ptp_clock = NULL;
321	} else if (priv->ptp_clock)
322		netdev_info(priv->dev, "registered PTP clock\n");
323}
324
325/**
326 * stmmac_ptp_unregister
327 * @priv: driver private structure
328 * Description: this function will remove/unregister the ptp clock driver
329 * from the kernel.
330 */
331void stmmac_ptp_unregister(struct stmmac_priv *priv)
332{
333	if (priv->ptp_clock) {
334		ptp_clock_unregister(priv->ptp_clock);
335		priv->ptp_clock = NULL;
336		pr_debug("Removed PTP HW clock successfully on %s\n",
337			 priv->dev->name);
338	}
339
340	mutex_destroy(&priv->aux_ts_lock);
341}
342