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(base: 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(dividend: delta, divisor: 1000000000ULL, remainder: &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(lock: &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(ts: 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(ts: 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(old_base_time: basetime,
99 current_time: 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(lock: &priv->plat->est->lock);
108 if (ret)
109 netdev_err(dev: priv->dev, format: "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(nsec: 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(addr: 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(dev: priv->dev,
205 format: "Cannot enable auxiliary snapshot %d as auxiliary snapshot %d is already enabled",
206 rq->extts.index, channel);
207 mutex_unlock(lock: &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(val: acr_value, addr: ptpaddr + PTP_ACR);
222 mutex_unlock(lock: &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(get_time_fn: stmmac_get_syncdevicetime,
264 ctx: 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(info: &priv->ptp_clock_ops,
317 parent: priv->device);
318 if (IS_ERR(ptr: priv->ptp_clock)) {
319 netdev_err(dev: priv->dev, format: "ptp_clock_register failed\n");
320 priv->ptp_clock = NULL;
321 } else if (priv->ptp_clock)
322 netdev_info(dev: priv->dev, format: "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(ptp: 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(lock: &priv->aux_ts_lock);
341}
342

source code of linux/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c