linux/drivers/net/ethernet/cadence/macb_ptp.c
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   1/**
   2 * 1588 PTP support for Cadence GEM device.
   3 *
   4 * Copyright (C) 2017 Cadence Design Systems - http://www.cadence.com
   5 *
   6 * Authors: Rafal Ozieblo <rafalo@cadence.com>
   7 *          Bartosz Folta <bfolta@cadence.com>
   8 *
   9 * This program is free software: you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2  of
  11 * the License as published by the Free Software Foundation.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21#include <linux/kernel.h>
  22#include <linux/types.h>
  23#include <linux/clk.h>
  24#include <linux/device.h>
  25#include <linux/etherdevice.h>
  26#include <linux/platform_device.h>
  27#include <linux/time64.h>
  28#include <linux/ptp_classify.h>
  29#include <linux/if_ether.h>
  30#include <linux/if_vlan.h>
  31#include <linux/net_tstamp.h>
  32#include <linux/circ_buf.h>
  33#include <linux/spinlock.h>
  34
  35#include "macb.h"
  36
  37#define  GEM_PTP_TIMER_NAME "gem-ptp-timer"
  38
  39static struct macb_dma_desc_ptp *macb_ptp_desc(struct macb *bp,
  40                                               struct macb_dma_desc *desc)
  41{
  42        if (bp->hw_dma_cap == HW_DMA_CAP_PTP)
  43                return (struct macb_dma_desc_ptp *)
  44                                ((u8 *)desc + sizeof(struct macb_dma_desc));
  45        if (bp->hw_dma_cap == HW_DMA_CAP_64B_PTP)
  46                return (struct macb_dma_desc_ptp *)
  47                                ((u8 *)desc + sizeof(struct macb_dma_desc)
  48                                + sizeof(struct macb_dma_desc_64));
  49        return NULL;
  50}
  51
  52static int gem_tsu_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts)
  53{
  54        struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
  55        unsigned long flags;
  56        long first, second;
  57        u32 secl, sech;
  58
  59        spin_lock_irqsave(&bp->tsu_clk_lock, flags);
  60        first = gem_readl(bp, TN);
  61        secl = gem_readl(bp, TSL);
  62        sech = gem_readl(bp, TSH);
  63        second = gem_readl(bp, TN);
  64
  65        /* test for nsec rollover */
  66        if (first > second) {
  67                /* if so, use later read & re-read seconds
  68                 * (assume all done within 1s)
  69                 */
  70                ts->tv_nsec = gem_readl(bp, TN);
  71                secl = gem_readl(bp, TSL);
  72                sech = gem_readl(bp, TSH);
  73        } else {
  74                ts->tv_nsec = first;
  75        }
  76
  77        spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);
  78        ts->tv_sec = (((u64)sech << GEM_TSL_SIZE) | secl)
  79                        & TSU_SEC_MAX_VAL;
  80        return 0;
  81}
  82
  83static int gem_tsu_set_time(struct ptp_clock_info *ptp,
  84                            const struct timespec64 *ts)
  85{
  86        struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
  87        unsigned long flags;
  88        u32 ns, sech, secl;
  89
  90        secl = (u32)ts->tv_sec;
  91        sech = (ts->tv_sec >> GEM_TSL_SIZE) & ((1 << GEM_TSH_SIZE) - 1);
  92        ns = ts->tv_nsec;
  93
  94        spin_lock_irqsave(&bp->tsu_clk_lock, flags);
  95
  96        /* TSH doesn't latch the time and no atomicity! */
  97        gem_writel(bp, TN, 0); /* clear to avoid overflow */
  98        gem_writel(bp, TSH, sech);
  99        /* write lower bits 2nd, for synchronized secs update */
 100        gem_writel(bp, TSL, secl);
 101        gem_writel(bp, TN, ns);
 102
 103        spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);
 104
 105        return 0;
 106}
 107
 108static int gem_tsu_incr_set(struct macb *bp, struct tsu_incr *incr_spec)
 109{
 110        unsigned long flags;
 111
 112        /* tsu_timer_incr register must be written after
 113         * the tsu_timer_incr_sub_ns register and the write operation
 114         * will cause the value written to the tsu_timer_incr_sub_ns register
 115         * to take effect.
 116         */
 117        spin_lock_irqsave(&bp->tsu_clk_lock, flags);
 118        gem_writel(bp, TISUBN, GEM_BF(SUBNSINCR, incr_spec->sub_ns));
 119        gem_writel(bp, TI, GEM_BF(NSINCR, incr_spec->ns));
 120        spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);
 121
 122        return 0;
 123}
 124
 125static int gem_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 126{
 127        struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
 128        struct tsu_incr incr_spec;
 129        bool neg_adj = false;
 130        u32 word;
 131        u64 adj;
 132
 133        if (scaled_ppm < 0) {
 134                neg_adj = true;
 135                scaled_ppm = -scaled_ppm;
 136        }
 137
 138        /* Adjustment is relative to base frequency */
 139        incr_spec.sub_ns = bp->tsu_incr.sub_ns;
 140        incr_spec.ns = bp->tsu_incr.ns;
 141
 142        /* scaling: unused(8bit) | ns(8bit) | fractions(16bit) */
 143        word = ((u64)incr_spec.ns << GEM_SUBNSINCR_SIZE) + incr_spec.sub_ns;
 144        adj = (u64)scaled_ppm * word;
 145        /* Divide with rounding, equivalent to floating dividing:
 146         * (temp / USEC_PER_SEC) + 0.5
 147         */
 148        adj += (USEC_PER_SEC >> 1);
 149        adj >>= GEM_SUBNSINCR_SIZE; /* remove fractions */
 150        adj = div_u64(adj, USEC_PER_SEC);
 151        adj = neg_adj ? (word - adj) : (word + adj);
 152
 153        incr_spec.ns = (adj >> GEM_SUBNSINCR_SIZE)
 154                        & ((1 << GEM_NSINCR_SIZE) - 1);
 155        incr_spec.sub_ns = adj & ((1 << GEM_SUBNSINCR_SIZE) - 1);
 156        gem_tsu_incr_set(bp, &incr_spec);
 157        return 0;
 158}
 159
 160static int gem_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 161{
 162        struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
 163        struct timespec64 now, then = ns_to_timespec64(delta);
 164        u32 adj, sign = 0;
 165
 166        if (delta < 0) {
 167                sign = 1;
 168                delta = -delta;
 169        }
 170
 171        if (delta > TSU_NSEC_MAX_VAL) {
 172                gem_tsu_get_time(&bp->ptp_clock_info, &now);
 173                if (sign)
 174                        now = timespec64_sub(now, then);
 175                else
 176                        now = timespec64_add(now, then);
 177
 178                gem_tsu_set_time(&bp->ptp_clock_info,
 179                                 (const struct timespec64 *)&now);
 180        } else {
 181                adj = (sign << GEM_ADDSUB_OFFSET) | delta;
 182
 183                gem_writel(bp, TA, adj);
 184        }
 185
 186        return 0;
 187}
 188
 189static int gem_ptp_enable(struct ptp_clock_info *ptp,
 190                          struct ptp_clock_request *rq, int on)
 191{
 192        return -EOPNOTSUPP;
 193}
 194
 195static const struct ptp_clock_info gem_ptp_caps_template = {
 196        .owner          = THIS_MODULE,
 197        .name           = GEM_PTP_TIMER_NAME,
 198        .max_adj        = 0,
 199        .n_alarm        = 0,
 200        .n_ext_ts       = 0,
 201        .n_per_out      = 0,
 202        .n_pins         = 0,
 203        .pps            = 1,
 204        .adjfine        = gem_ptp_adjfine,
 205        .adjtime        = gem_ptp_adjtime,
 206        .gettime64      = gem_tsu_get_time,
 207        .settime64      = gem_tsu_set_time,
 208        .enable         = gem_ptp_enable,
 209};
 210
 211static void gem_ptp_init_timer(struct macb *bp)
 212{
 213        u32 rem = 0;
 214        u64 adj;
 215
 216        bp->tsu_incr.ns = div_u64_rem(NSEC_PER_SEC, bp->tsu_rate, &rem);
 217        if (rem) {
 218                adj = rem;
 219                adj <<= GEM_SUBNSINCR_SIZE;
 220                bp->tsu_incr.sub_ns = div_u64(adj, bp->tsu_rate);
 221        } else {
 222                bp->tsu_incr.sub_ns = 0;
 223        }
 224}
 225
 226static void gem_ptp_init_tsu(struct macb *bp)
 227{
 228        struct timespec64 ts;
 229
 230        /* 1. get current system time */
 231        ts = ns_to_timespec64(ktime_to_ns(ktime_get_real()));
 232
 233        /* 2. set ptp timer */
 234        gem_tsu_set_time(&bp->ptp_clock_info, &ts);
 235
 236        /* 3. set PTP timer increment value to BASE_INCREMENT */
 237        gem_tsu_incr_set(bp, &bp->tsu_incr);
 238
 239        gem_writel(bp, TA, 0);
 240}
 241
 242static void gem_ptp_clear_timer(struct macb *bp)
 243{
 244        bp->tsu_incr.sub_ns = 0;
 245        bp->tsu_incr.ns = 0;
 246
 247        gem_writel(bp, TISUBN, GEM_BF(SUBNSINCR, 0));
 248        gem_writel(bp, TI, GEM_BF(NSINCR, 0));
 249        gem_writel(bp, TA, 0);
 250}
 251
 252static int gem_hw_timestamp(struct macb *bp, u32 dma_desc_ts_1,
 253                            u32 dma_desc_ts_2, struct timespec64 *ts)
 254{
 255        struct timespec64 tsu;
 256
 257        ts->tv_sec = (GEM_BFEXT(DMA_SECH, dma_desc_ts_2) << GEM_DMA_SECL_SIZE) |
 258                        GEM_BFEXT(DMA_SECL, dma_desc_ts_1);
 259        ts->tv_nsec = GEM_BFEXT(DMA_NSEC, dma_desc_ts_1);
 260
 261        /* TSU overlapping workaround
 262         * The timestamp only contains lower few bits of seconds,
 263         * so add value from 1588 timer
 264         */
 265        gem_tsu_get_time(&bp->ptp_clock_info, &tsu);
 266
 267        /* If the top bit is set in the timestamp,
 268         * but not in 1588 timer, it has rolled over,
 269         * so subtract max size
 270         */
 271        if ((ts->tv_sec & (GEM_DMA_SEC_TOP >> 1)) &&
 272            !(tsu.tv_sec & (GEM_DMA_SEC_TOP >> 1)))
 273                ts->tv_sec -= GEM_DMA_SEC_TOP;
 274
 275        ts->tv_sec += ((~GEM_DMA_SEC_MASK) & tsu.tv_sec);
 276
 277        return 0;
 278}
 279
 280void gem_ptp_rxstamp(struct macb *bp, struct sk_buff *skb,
 281                     struct macb_dma_desc *desc)
 282{
 283        struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
 284        struct macb_dma_desc_ptp *desc_ptp;
 285        struct timespec64 ts;
 286
 287        if (GEM_BFEXT(DMA_RXVALID, desc->addr)) {
 288                desc_ptp = macb_ptp_desc(bp, desc);
 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        skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 322        desc_ptp = macb_ptp_desc(queue->bp, desc);
 323        tx_timestamp = &queue->tx_timestamps[head];
 324        tx_timestamp->skb = skb;
 325        tx_timestamp->desc_ptp.ts_1 = desc_ptp->ts_1;
 326        tx_timestamp->desc_ptp.ts_2 = desc_ptp->ts_2;
 327        /* move head */
 328        smp_store_release(&queue->tx_ts_head,
 329                          (head + 1) & (PTP_TS_BUFFER_SIZE - 1));
 330
 331        schedule_work(&queue->tx_ts_task);
 332        return 0;
 333}
 334
 335static void gem_tx_timestamp_flush(struct work_struct *work)
 336{
 337        struct macb_queue *queue =
 338                        container_of(work, struct macb_queue, tx_ts_task);
 339        unsigned long head, tail;
 340        struct gem_tx_ts *tx_ts;
 341
 342        /* take current head */
 343        head = smp_load_acquire(&queue->tx_ts_head);
 344        tail = queue->tx_ts_tail;
 345
 346        while (CIRC_CNT(head, tail, PTP_TS_BUFFER_SIZE)) {
 347                tx_ts = &queue->tx_timestamps[tail];
 348                gem_tstamp_tx(queue->bp, tx_ts->skb, &tx_ts->desc_ptp);
 349                /* cleanup */
 350                dev_kfree_skb_any(tx_ts->skb);
 351                /* remove old tail */
 352                smp_store_release(&queue->tx_ts_tail,
 353                                  (tail + 1) & (PTP_TS_BUFFER_SIZE - 1));
 354                tail = queue->tx_ts_tail;
 355        }
 356}
 357
 358void gem_ptp_init(struct net_device *dev)
 359{
 360        struct macb *bp = netdev_priv(dev);
 361        struct macb_queue *queue;
 362        unsigned int q;
 363
 364        bp->ptp_clock_info = gem_ptp_caps_template;
 365
 366        /* nominal frequency and maximum adjustment in ppb */
 367        bp->ptp_clock_info.max_adj = bp->ptp_info->get_ptp_max_adj();
 368        gem_ptp_init_timer(bp);
 369        bp->ptp_clock = ptp_clock_register(&bp->ptp_clock_info, &dev->dev);
 370        if (IS_ERR(bp->ptp_clock)) {
 371                pr_err("ptp clock register failed: %ld\n",
 372                        PTR_ERR(bp->ptp_clock));
 373                bp->ptp_clock = NULL;
 374                return;
 375        } else if (bp->ptp_clock == NULL) {
 376                pr_err("ptp clock register failed\n");
 377                return;
 378        }
 379
 380        spin_lock_init(&bp->tsu_clk_lock);
 381        for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
 382                queue->tx_ts_head = 0;
 383                queue->tx_ts_tail = 0;
 384                INIT_WORK(&queue->tx_ts_task, gem_tx_timestamp_flush);
 385        }
 386
 387        gem_ptp_init_tsu(bp);
 388
 389        dev_info(&bp->pdev->dev, "%s ptp clock registered.\n",
 390                 GEM_PTP_TIMER_NAME);
 391}
 392
 393void gem_ptp_remove(struct net_device *ndev)
 394{
 395        struct macb *bp = netdev_priv(ndev);
 396        unsigned long flags;
 397
 398        if (bp->ptp_clock)
 399                ptp_clock_unregister(bp->ptp_clock);
 400
 401        spin_lock_irqsave(&bp->tsu_clk_lock, flags);
 402        gem_ptp_clear_timer(bp);
 403        spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);
 404
 405        dev_info(&bp->pdev->dev, "%s ptp clock unregistered.\n",
 406                 GEM_PTP_TIMER_NAME);
 407}
 408
 409static int gem_ptp_set_ts_mode(struct macb *bp,
 410                               enum macb_bd_control tx_bd_control,
 411                               enum macb_bd_control rx_bd_control)
 412{
 413        gem_writel(bp, TXBDCTRL, GEM_BF(TXTSMODE, tx_bd_control));
 414        gem_writel(bp, RXBDCTRL, GEM_BF(RXTSMODE, rx_bd_control));
 415
 416        return 0;
 417}
 418
 419int gem_get_hwtst(struct net_device *dev, struct ifreq *rq)
 420{
 421        struct hwtstamp_config *tstamp_config;
 422        struct macb *bp = netdev_priv(dev);
 423
 424        tstamp_config = &bp->tstamp_config;
 425        if ((bp->hw_dma_cap & HW_DMA_CAP_PTP) == 0)
 426                return -EOPNOTSUPP;
 427
 428        if (copy_to_user(rq->ifr_data, tstamp_config, sizeof(*tstamp_config)))
 429                return -EFAULT;
 430        else
 431                return 0;
 432}
 433
 434static int gem_ptp_set_one_step_sync(struct macb *bp, u8 enable)
 435{
 436        u32 reg_val;
 437
 438        reg_val = macb_readl(bp, NCR);
 439
 440        if (enable)
 441                macb_writel(bp, NCR, reg_val | MACB_BIT(OSSMODE));
 442        else
 443                macb_writel(bp, NCR, reg_val & ~MACB_BIT(OSSMODE));
 444
 445        return 0;
 446}
 447
 448int gem_set_hwtst(struct net_device *dev, struct ifreq *ifr, int cmd)
 449{
 450        enum macb_bd_control tx_bd_control = TSTAMP_DISABLED;
 451        enum macb_bd_control rx_bd_control = TSTAMP_DISABLED;
 452        struct hwtstamp_config *tstamp_config;
 453        struct macb *bp = netdev_priv(dev);
 454        u32 regval;
 455
 456        tstamp_config = &bp->tstamp_config;
 457        if ((bp->hw_dma_cap & HW_DMA_CAP_PTP) == 0)
 458                return -EOPNOTSUPP;
 459
 460        if (copy_from_user(tstamp_config, ifr->ifr_data,
 461                           sizeof(*tstamp_config)))
 462                return -EFAULT;
 463
 464        /* reserved for future extensions */
 465        if (tstamp_config->flags)
 466                return -EINVAL;
 467
 468        switch (tstamp_config->tx_type) {
 469        case HWTSTAMP_TX_OFF:
 470                break;
 471        case HWTSTAMP_TX_ONESTEP_SYNC:
 472                if (gem_ptp_set_one_step_sync(bp, 1) != 0)
 473                        return -ERANGE;
 474        case HWTSTAMP_TX_ON:
 475                tx_bd_control = TSTAMP_ALL_FRAMES;
 476                break;
 477        default:
 478                return -ERANGE;
 479        }
 480
 481        switch (tstamp_config->rx_filter) {
 482        case HWTSTAMP_FILTER_NONE:
 483                break;
 484        case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
 485                break;
 486        case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
 487                break;
 488        case HWTSTAMP_FILTER_PTP_V2_EVENT:
 489        case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
 490        case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
 491        case HWTSTAMP_FILTER_PTP_V2_SYNC:
 492        case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
 493        case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
 494        case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
 495        case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
 496        case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
 497                rx_bd_control =  TSTAMP_ALL_PTP_FRAMES;
 498                tstamp_config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
 499                regval = macb_readl(bp, NCR);
 500                macb_writel(bp, NCR, (regval | MACB_BIT(SRTSM)));
 501                break;
 502        case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
 503        case HWTSTAMP_FILTER_ALL:
 504                rx_bd_control = TSTAMP_ALL_FRAMES;
 505                tstamp_config->rx_filter = HWTSTAMP_FILTER_ALL;
 506                break;
 507        default:
 508                tstamp_config->rx_filter = HWTSTAMP_FILTER_NONE;
 509                return -ERANGE;
 510        }
 511
 512        if (gem_ptp_set_ts_mode(bp, tx_bd_control, rx_bd_control) != 0)
 513                return -ERANGE;
 514
 515        if (copy_to_user(ifr->ifr_data, tstamp_config, sizeof(*tstamp_config)))
 516                return -EFAULT;
 517        else
 518                return 0;
 519}
 520
 521