linux/drivers/net/ethernet/cadence/macb_ptp.c
<<
>>
Prefs
   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
  28static 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
  41static 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
  77static 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
 102static 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
 122static 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
 157static 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
 183static int gem_ptp_enable(struct ptp_clock_info *ptp,
 184                          struct ptp_clock_request *rq, int on)
 185{
 186        return -EOPNOTSUPP;
 187}
 188
 189static 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
 205static 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
 220static 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
 236static 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
 246static 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
 274void 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
 295static 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
 307int 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
 340static 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
 363void 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
 399void 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
 412static 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
 422int 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
 437static int 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        return 0;
 449}
 450
 451int gem_set_hwtst(struct net_device *dev, struct ifreq *ifr, int cmd)
 452{
 453        enum macb_bd_control tx_bd_control = TSTAMP_DISABLED;
 454        enum macb_bd_control rx_bd_control = TSTAMP_DISABLED;
 455        struct hwtstamp_config *tstamp_config;
 456        struct macb *bp = netdev_priv(dev);
 457        u32 regval;
 458
 459        tstamp_config = &bp->tstamp_config;
 460        if ((bp->hw_dma_cap & HW_DMA_CAP_PTP) == 0)
 461                return -EOPNOTSUPP;
 462
 463        if (copy_from_user(tstamp_config, ifr->ifr_data,
 464                           sizeof(*tstamp_config)))
 465                return -EFAULT;
 466
 467        switch (tstamp_config->tx_type) {
 468        case HWTSTAMP_TX_OFF:
 469                break;
 470        case HWTSTAMP_TX_ONESTEP_SYNC:
 471                if (gem_ptp_set_one_step_sync(bp, 1) != 0)
 472                        return -ERANGE;
 473                tx_bd_control = TSTAMP_ALL_FRAMES;
 474                break;
 475        case HWTSTAMP_TX_ON:
 476                gem_ptp_set_one_step_sync(bp, 0);
 477                tx_bd_control = TSTAMP_ALL_FRAMES;
 478                break;
 479        default:
 480                return -ERANGE;
 481        }
 482
 483        switch (tstamp_config->rx_filter) {
 484        case HWTSTAMP_FILTER_NONE:
 485                break;
 486        case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
 487                break;
 488        case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
 489                break;
 490        case HWTSTAMP_FILTER_PTP_V2_EVENT:
 491        case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
 492        case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
 493        case HWTSTAMP_FILTER_PTP_V2_SYNC:
 494        case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
 495        case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
 496        case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
 497        case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
 498        case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
 499                rx_bd_control =  TSTAMP_ALL_PTP_FRAMES;
 500                tstamp_config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
 501                regval = macb_readl(bp, NCR);
 502                macb_writel(bp, NCR, (regval | MACB_BIT(SRTSM)));
 503                break;
 504        case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
 505        case HWTSTAMP_FILTER_ALL:
 506                rx_bd_control = TSTAMP_ALL_FRAMES;
 507                tstamp_config->rx_filter = HWTSTAMP_FILTER_ALL;
 508                break;
 509        default:
 510                tstamp_config->rx_filter = HWTSTAMP_FILTER_NONE;
 511                return -ERANGE;
 512        }
 513
 514        if (gem_ptp_set_ts_mode(bp, tx_bd_control, rx_bd_control) != 0)
 515                return -ERANGE;
 516
 517        if (copy_to_user(ifr->ifr_data, tstamp_config, sizeof(*tstamp_config)))
 518                return -EFAULT;
 519        else
 520                return 0;
 521}
 522
 523