1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * 1588 PTP support for Cadence GEM device.
4 *
5 * Copyright (C) 2017 Cadence Design Systems - https://www.cadence.com
6 *
7 * Authors: Rafal Ozieblo <rafalo@cadence.com>
8 * Bartosz Folta <bfolta@cadence.com>
9 */
10 #include <linux/kernel.h>
11 #include <linux/types.h>
12 #include <linux/clk.h>
13 #include <linux/device.h>
14 #include <linux/etherdevice.h>
15 #include <linux/platform_device.h>
16 #include <linux/time64.h>
17 #include <linux/ptp_classify.h>
18 #include <linux/if_ether.h>
19 #include <linux/if_vlan.h>
20 #include <linux/net_tstamp.h>
21 #include <linux/circ_buf.h>
22 #include <linux/spinlock.h>
23
24 #include "macb.h"
25
26 #define GEM_PTP_TIMER_NAME "gem-ptp-timer"
27
macb_ptp_desc(struct macb * bp,struct macb_dma_desc * desc)28 static struct macb_dma_desc_ptp *macb_ptp_desc(struct macb *bp,
29 struct macb_dma_desc *desc)
30 {
31 if (bp->hw_dma_cap == HW_DMA_CAP_PTP)
32 return (struct macb_dma_desc_ptp *)
33 ((u8 *)desc + sizeof(struct macb_dma_desc));
34 if (bp->hw_dma_cap == HW_DMA_CAP_64B_PTP)
35 return (struct macb_dma_desc_ptp *)
36 ((u8 *)desc + sizeof(struct macb_dma_desc)
37 + sizeof(struct macb_dma_desc_64));
38 return NULL;
39 }
40
gem_tsu_get_time(struct ptp_clock_info * ptp,struct timespec64 * ts,struct ptp_system_timestamp * sts)41 static int gem_tsu_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts,
42 struct ptp_system_timestamp *sts)
43 {
44 struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
45 unsigned long flags;
46 long first, second;
47 u32 secl, sech;
48
49 spin_lock_irqsave(&bp->tsu_clk_lock, flags);
50 ptp_read_system_prets(sts);
51 first = gem_readl(bp, TN);
52 ptp_read_system_postts(sts);
53 secl = gem_readl(bp, TSL);
54 sech = gem_readl(bp, TSH);
55 second = gem_readl(bp, TN);
56
57 /* test for nsec rollover */
58 if (first > second) {
59 /* if so, use later read & re-read seconds
60 * (assume all done within 1s)
61 */
62 ptp_read_system_prets(sts);
63 ts->tv_nsec = gem_readl(bp, TN);
64 ptp_read_system_postts(sts);
65 secl = gem_readl(bp, TSL);
66 sech = gem_readl(bp, TSH);
67 } else {
68 ts->tv_nsec = first;
69 }
70
71 spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);
72 ts->tv_sec = (((u64)sech << GEM_TSL_SIZE) | secl)
73 & TSU_SEC_MAX_VAL;
74 return 0;
75 }
76
gem_tsu_set_time(struct ptp_clock_info * ptp,const struct timespec64 * ts)77 static int gem_tsu_set_time(struct ptp_clock_info *ptp,
78 const struct timespec64 *ts)
79 {
80 struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
81 unsigned long flags;
82 u32 ns, sech, secl;
83
84 secl = (u32)ts->tv_sec;
85 sech = (ts->tv_sec >> GEM_TSL_SIZE) & ((1 << GEM_TSH_SIZE) - 1);
86 ns = ts->tv_nsec;
87
88 spin_lock_irqsave(&bp->tsu_clk_lock, flags);
89
90 /* TSH doesn't latch the time and no atomicity! */
91 gem_writel(bp, TN, 0); /* clear to avoid overflow */
92 gem_writel(bp, TSH, sech);
93 /* write lower bits 2nd, for synchronized secs update */
94 gem_writel(bp, TSL, secl);
95 gem_writel(bp, TN, ns);
96
97 spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);
98
99 return 0;
100 }
101
gem_tsu_incr_set(struct macb * bp,struct tsu_incr * incr_spec)102 static int gem_tsu_incr_set(struct macb *bp, struct tsu_incr *incr_spec)
103 {
104 unsigned long flags;
105
106 /* tsu_timer_incr register must be written after
107 * the tsu_timer_incr_sub_ns register and the write operation
108 * will cause the value written to the tsu_timer_incr_sub_ns register
109 * to take effect.
110 */
111 spin_lock_irqsave(&bp->tsu_clk_lock, flags);
112 /* RegBit[15:0] = Subns[23:8]; RegBit[31:24] = Subns[7:0] */
113 gem_writel(bp, TISUBN, GEM_BF(SUBNSINCRL, incr_spec->sub_ns) |
114 GEM_BF(SUBNSINCRH, (incr_spec->sub_ns >>
115 GEM_SUBNSINCRL_SIZE)));
116 gem_writel(bp, TI, GEM_BF(NSINCR, incr_spec->ns));
117 spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);
118
119 return 0;
120 }
121
gem_ptp_adjfine(struct ptp_clock_info * ptp,long scaled_ppm)122 static int gem_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
123 {
124 struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
125 struct tsu_incr incr_spec;
126 bool neg_adj = false;
127 u32 word;
128 u64 adj;
129
130 if (scaled_ppm < 0) {
131 neg_adj = true;
132 scaled_ppm = -scaled_ppm;
133 }
134
135 /* Adjustment is relative to base frequency */
136 incr_spec.sub_ns = bp->tsu_incr.sub_ns;
137 incr_spec.ns = bp->tsu_incr.ns;
138
139 /* scaling: unused(8bit) | ns(8bit) | fractions(16bit) */
140 word = ((u64)incr_spec.ns << GEM_SUBNSINCR_SIZE) + incr_spec.sub_ns;
141 adj = (u64)scaled_ppm * word;
142 /* Divide with rounding, equivalent to floating dividing:
143 * (temp / USEC_PER_SEC) + 0.5
144 */
145 adj += (USEC_PER_SEC >> 1);
146 adj >>= PPM_FRACTION; /* remove fractions */
147 adj = div_u64(adj, USEC_PER_SEC);
148 adj = neg_adj ? (word - adj) : (word + adj);
149
150 incr_spec.ns = (adj >> GEM_SUBNSINCR_SIZE)
151 & ((1 << GEM_NSINCR_SIZE) - 1);
152 incr_spec.sub_ns = adj & ((1 << GEM_SUBNSINCR_SIZE) - 1);
153 gem_tsu_incr_set(bp, &incr_spec);
154 return 0;
155 }
156
gem_ptp_adjtime(struct ptp_clock_info * ptp,s64 delta)157 static int gem_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
158 {
159 struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
160 struct timespec64 now, then = ns_to_timespec64(delta);
161 u32 adj, sign = 0;
162
163 if (delta < 0) {
164 sign = 1;
165 delta = -delta;
166 }
167
168 if (delta > TSU_NSEC_MAX_VAL) {
169 gem_tsu_get_time(&bp->ptp_clock_info, &now, NULL);
170 now = timespec64_add(now, then);
171
172 gem_tsu_set_time(&bp->ptp_clock_info,
173 (const struct timespec64 *)&now);
174 } else {
175 adj = (sign << GEM_ADDSUB_OFFSET) | delta;
176
177 gem_writel(bp, TA, adj);
178 }
179
180 return 0;
181 }
182
gem_ptp_enable(struct ptp_clock_info * ptp,struct ptp_clock_request * rq,int on)183 static int gem_ptp_enable(struct ptp_clock_info *ptp,
184 struct ptp_clock_request *rq, int on)
185 {
186 return -EOPNOTSUPP;
187 }
188
189 static const struct ptp_clock_info gem_ptp_caps_template = {
190 .owner = THIS_MODULE,
191 .name = GEM_PTP_TIMER_NAME,
192 .max_adj = 0,
193 .n_alarm = 0,
194 .n_ext_ts = 0,
195 .n_per_out = 0,
196 .n_pins = 0,
197 .pps = 1,
198 .adjfine = gem_ptp_adjfine,
199 .adjtime = gem_ptp_adjtime,
200 .gettimex64 = gem_tsu_get_time,
201 .settime64 = gem_tsu_set_time,
202 .enable = gem_ptp_enable,
203 };
204
gem_ptp_init_timer(struct macb * bp)205 static void gem_ptp_init_timer(struct macb *bp)
206 {
207 u32 rem = 0;
208 u64 adj;
209
210 bp->tsu_incr.ns = div_u64_rem(NSEC_PER_SEC, bp->tsu_rate, &rem);
211 if (rem) {
212 adj = rem;
213 adj <<= GEM_SUBNSINCR_SIZE;
214 bp->tsu_incr.sub_ns = div_u64(adj, bp->tsu_rate);
215 } else {
216 bp->tsu_incr.sub_ns = 0;
217 }
218 }
219
gem_ptp_init_tsu(struct macb * bp)220 static void gem_ptp_init_tsu(struct macb *bp)
221 {
222 struct timespec64 ts;
223
224 /* 1. get current system time */
225 ts = ns_to_timespec64(ktime_to_ns(ktime_get_real()));
226
227 /* 2. set ptp timer */
228 gem_tsu_set_time(&bp->ptp_clock_info, &ts);
229
230 /* 3. set PTP timer increment value to BASE_INCREMENT */
231 gem_tsu_incr_set(bp, &bp->tsu_incr);
232
233 gem_writel(bp, TA, 0);
234 }
235
gem_ptp_clear_timer(struct macb * bp)236 static void gem_ptp_clear_timer(struct macb *bp)
237 {
238 bp->tsu_incr.sub_ns = 0;
239 bp->tsu_incr.ns = 0;
240
241 gem_writel(bp, TISUBN, GEM_BF(SUBNSINCR, 0));
242 gem_writel(bp, TI, GEM_BF(NSINCR, 0));
243 gem_writel(bp, TA, 0);
244 }
245
gem_hw_timestamp(struct macb * bp,u32 dma_desc_ts_1,u32 dma_desc_ts_2,struct timespec64 * ts)246 static int gem_hw_timestamp(struct macb *bp, u32 dma_desc_ts_1,
247 u32 dma_desc_ts_2, struct timespec64 *ts)
248 {
249 struct timespec64 tsu;
250
251 ts->tv_sec = (GEM_BFEXT(DMA_SECH, dma_desc_ts_2) << GEM_DMA_SECL_SIZE) |
252 GEM_BFEXT(DMA_SECL, dma_desc_ts_1);
253 ts->tv_nsec = GEM_BFEXT(DMA_NSEC, dma_desc_ts_1);
254
255 /* TSU overlapping workaround
256 * The timestamp only contains lower few bits of seconds,
257 * so add value from 1588 timer
258 */
259 gem_tsu_get_time(&bp->ptp_clock_info, &tsu, NULL);
260
261 /* If the top bit is set in the timestamp,
262 * but not in 1588 timer, it has rolled over,
263 * so subtract max size
264 */
265 if ((ts->tv_sec & (GEM_DMA_SEC_TOP >> 1)) &&
266 !(tsu.tv_sec & (GEM_DMA_SEC_TOP >> 1)))
267 ts->tv_sec -= GEM_DMA_SEC_TOP;
268
269 ts->tv_sec += ((~GEM_DMA_SEC_MASK) & tsu.tv_sec);
270
271 return 0;
272 }
273
gem_ptp_rxstamp(struct macb * bp,struct sk_buff * skb,struct macb_dma_desc * desc)274 void gem_ptp_rxstamp(struct macb *bp, struct sk_buff *skb,
275 struct macb_dma_desc *desc)
276 {
277 struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
278 struct macb_dma_desc_ptp *desc_ptp;
279 struct timespec64 ts;
280
281 if (GEM_BFEXT(DMA_RXVALID, desc->addr)) {
282 desc_ptp = macb_ptp_desc(bp, desc);
283 /* Unlikely but check */
284 if (!desc_ptp) {
285 dev_warn_ratelimited(&bp->pdev->dev,
286 "Timestamp not supported in BD\n");
287 return;
288 }
289 gem_hw_timestamp(bp, desc_ptp->ts_1, desc_ptp->ts_2, &ts);
290 memset(shhwtstamps, 0, sizeof(struct skb_shared_hwtstamps));
291 shhwtstamps->hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
292 }
293 }
294
gem_tstamp_tx(struct macb * bp,struct sk_buff * skb,struct macb_dma_desc_ptp * desc_ptp)295 static void gem_tstamp_tx(struct macb *bp, struct sk_buff *skb,
296 struct macb_dma_desc_ptp *desc_ptp)
297 {
298 struct skb_shared_hwtstamps shhwtstamps;
299 struct timespec64 ts;
300
301 gem_hw_timestamp(bp, desc_ptp->ts_1, desc_ptp->ts_2, &ts);
302 memset(&shhwtstamps, 0, sizeof(shhwtstamps));
303 shhwtstamps.hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
304 skb_tstamp_tx(skb, &shhwtstamps);
305 }
306
gem_ptp_txstamp(struct macb_queue * queue,struct sk_buff * skb,struct macb_dma_desc * desc)307 int gem_ptp_txstamp(struct macb_queue *queue, struct sk_buff *skb,
308 struct macb_dma_desc *desc)
309 {
310 unsigned long tail = READ_ONCE(queue->tx_ts_tail);
311 unsigned long head = queue->tx_ts_head;
312 struct macb_dma_desc_ptp *desc_ptp;
313 struct gem_tx_ts *tx_timestamp;
314
315 if (!GEM_BFEXT(DMA_TXVALID, desc->ctrl))
316 return -EINVAL;
317
318 if (CIRC_SPACE(head, tail, PTP_TS_BUFFER_SIZE) == 0)
319 return -ENOMEM;
320
321 desc_ptp = macb_ptp_desc(queue->bp, desc);
322 /* Unlikely but check */
323 if (!desc_ptp)
324 return -EINVAL;
325 skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
326 tx_timestamp = &queue->tx_timestamps[head];
327 tx_timestamp->skb = skb;
328 /* ensure ts_1/ts_2 is loaded after ctrl (TX_USED check) */
329 dma_rmb();
330 tx_timestamp->desc_ptp.ts_1 = desc_ptp->ts_1;
331 tx_timestamp->desc_ptp.ts_2 = desc_ptp->ts_2;
332 /* move head */
333 smp_store_release(&queue->tx_ts_head,
334 (head + 1) & (PTP_TS_BUFFER_SIZE - 1));
335
336 schedule_work(&queue->tx_ts_task);
337 return 0;
338 }
339
gem_tx_timestamp_flush(struct work_struct * work)340 static void gem_tx_timestamp_flush(struct work_struct *work)
341 {
342 struct macb_queue *queue =
343 container_of(work, struct macb_queue, tx_ts_task);
344 unsigned long head, tail;
345 struct gem_tx_ts *tx_ts;
346
347 /* take current head */
348 head = smp_load_acquire(&queue->tx_ts_head);
349 tail = queue->tx_ts_tail;
350
351 while (CIRC_CNT(head, tail, PTP_TS_BUFFER_SIZE)) {
352 tx_ts = &queue->tx_timestamps[tail];
353 gem_tstamp_tx(queue->bp, tx_ts->skb, &tx_ts->desc_ptp);
354 /* cleanup */
355 dev_kfree_skb_any(tx_ts->skb);
356 /* remove old tail */
357 smp_store_release(&queue->tx_ts_tail,
358 (tail + 1) & (PTP_TS_BUFFER_SIZE - 1));
359 tail = queue->tx_ts_tail;
360 }
361 }
362
gem_ptp_init(struct net_device * dev)363 void gem_ptp_init(struct net_device *dev)
364 {
365 struct macb *bp = netdev_priv(dev);
366 struct macb_queue *queue;
367 unsigned int q;
368
369 bp->ptp_clock_info = gem_ptp_caps_template;
370
371 /* nominal frequency and maximum adjustment in ppb */
372 bp->tsu_rate = bp->ptp_info->get_tsu_rate(bp);
373 bp->ptp_clock_info.max_adj = bp->ptp_info->get_ptp_max_adj();
374 gem_ptp_init_timer(bp);
375 bp->ptp_clock = ptp_clock_register(&bp->ptp_clock_info, &dev->dev);
376 if (IS_ERR(bp->ptp_clock)) {
377 pr_err("ptp clock register failed: %ld\n",
378 PTR_ERR(bp->ptp_clock));
379 bp->ptp_clock = NULL;
380 return;
381 } else if (bp->ptp_clock == NULL) {
382 pr_err("ptp clock register failed\n");
383 return;
384 }
385
386 spin_lock_init(&bp->tsu_clk_lock);
387 for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
388 queue->tx_ts_head = 0;
389 queue->tx_ts_tail = 0;
390 INIT_WORK(&queue->tx_ts_task, gem_tx_timestamp_flush);
391 }
392
393 gem_ptp_init_tsu(bp);
394
395 dev_info(&bp->pdev->dev, "%s ptp clock registered.\n",
396 GEM_PTP_TIMER_NAME);
397 }
398
gem_ptp_remove(struct net_device * ndev)399 void gem_ptp_remove(struct net_device *ndev)
400 {
401 struct macb *bp = netdev_priv(ndev);
402
403 if (bp->ptp_clock)
404 ptp_clock_unregister(bp->ptp_clock);
405
406 gem_ptp_clear_timer(bp);
407
408 dev_info(&bp->pdev->dev, "%s ptp clock unregistered.\n",
409 GEM_PTP_TIMER_NAME);
410 }
411
gem_ptp_set_ts_mode(struct macb * bp,enum macb_bd_control tx_bd_control,enum macb_bd_control rx_bd_control)412 static int gem_ptp_set_ts_mode(struct macb *bp,
413 enum macb_bd_control tx_bd_control,
414 enum macb_bd_control rx_bd_control)
415 {
416 gem_writel(bp, TXBDCTRL, GEM_BF(TXTSMODE, tx_bd_control));
417 gem_writel(bp, RXBDCTRL, GEM_BF(RXTSMODE, rx_bd_control));
418
419 return 0;
420 }
421
gem_get_hwtst(struct net_device * dev,struct ifreq * rq)422 int gem_get_hwtst(struct net_device *dev, struct ifreq *rq)
423 {
424 struct hwtstamp_config *tstamp_config;
425 struct macb *bp = netdev_priv(dev);
426
427 tstamp_config = &bp->tstamp_config;
428 if ((bp->hw_dma_cap & HW_DMA_CAP_PTP) == 0)
429 return -EOPNOTSUPP;
430
431 if (copy_to_user(rq->ifr_data, tstamp_config, sizeof(*tstamp_config)))
432 return -EFAULT;
433 else
434 return 0;
435 }
436
gem_ptp_set_one_step_sync(struct macb * bp,u8 enable)437 static void gem_ptp_set_one_step_sync(struct macb *bp, u8 enable)
438 {
439 u32 reg_val;
440
441 reg_val = macb_readl(bp, NCR);
442
443 if (enable)
444 macb_writel(bp, NCR, reg_val | MACB_BIT(OSSMODE));
445 else
446 macb_writel(bp, NCR, reg_val & ~MACB_BIT(OSSMODE));
447 }
448
gem_set_hwtst(struct net_device * dev,struct ifreq * ifr,int cmd)449 int gem_set_hwtst(struct net_device *dev, struct ifreq *ifr, int cmd)
450 {
451 enum macb_bd_control tx_bd_control = TSTAMP_DISABLED;
452 enum macb_bd_control rx_bd_control = TSTAMP_DISABLED;
453 struct hwtstamp_config *tstamp_config;
454 struct macb *bp = netdev_priv(dev);
455 u32 regval;
456
457 tstamp_config = &bp->tstamp_config;
458 if ((bp->hw_dma_cap & HW_DMA_CAP_PTP) == 0)
459 return -EOPNOTSUPP;
460
461 if (copy_from_user(tstamp_config, ifr->ifr_data,
462 sizeof(*tstamp_config)))
463 return -EFAULT;
464
465 switch (tstamp_config->tx_type) {
466 case HWTSTAMP_TX_OFF:
467 break;
468 case HWTSTAMP_TX_ONESTEP_SYNC:
469 gem_ptp_set_one_step_sync(bp, 1);
470 tx_bd_control = TSTAMP_ALL_FRAMES;
471 break;
472 case HWTSTAMP_TX_ON:
473 gem_ptp_set_one_step_sync(bp, 0);
474 tx_bd_control = TSTAMP_ALL_FRAMES;
475 break;
476 default:
477 return -ERANGE;
478 }
479
480 switch (tstamp_config->rx_filter) {
481 case HWTSTAMP_FILTER_NONE:
482 break;
483 case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
484 break;
485 case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
486 break;
487 case HWTSTAMP_FILTER_PTP_V2_EVENT:
488 case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
489 case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
490 case HWTSTAMP_FILTER_PTP_V2_SYNC:
491 case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
492 case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
493 case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
494 case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
495 case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
496 rx_bd_control = TSTAMP_ALL_PTP_FRAMES;
497 tstamp_config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
498 regval = macb_readl(bp, NCR);
499 macb_writel(bp, NCR, (regval | MACB_BIT(SRTSM)));
500 break;
501 case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
502 case HWTSTAMP_FILTER_ALL:
503 rx_bd_control = TSTAMP_ALL_FRAMES;
504 tstamp_config->rx_filter = HWTSTAMP_FILTER_ALL;
505 break;
506 default:
507 tstamp_config->rx_filter = HWTSTAMP_FILTER_NONE;
508 return -ERANGE;
509 }
510
511 if (gem_ptp_set_ts_mode(bp, tx_bd_control, rx_bd_control) != 0)
512 return -ERANGE;
513
514 if (copy_to_user(ifr->ifr_data, tstamp_config, sizeof(*tstamp_config)))
515 return -EFAULT;
516 else
517 return 0;
518 }
519
520
