linux/drivers/net/ethernet/arc/emac_main.c
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   1/*
   2 * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 *
   8 * Driver for the ARC EMAC 10100 (hardware revision 5)
   9 *
  10 * Contributors:
  11 *              Amit Bhor
  12 *              Sameer Dhavale
  13 *              Vineet Gupta
  14 */
  15
  16#include <linux/crc32.h>
  17#include <linux/etherdevice.h>
  18#include <linux/interrupt.h>
  19#include <linux/io.h>
  20#include <linux/module.h>
  21#include <linux/of_address.h>
  22#include <linux/of_irq.h>
  23#include <linux/of_mdio.h>
  24#include <linux/of_net.h>
  25#include <linux/of_platform.h>
  26
  27#include "emac.h"
  28
  29/**
  30 * arc_emac_tx_avail - Return the number of available slots in the tx ring.
  31 * @priv: Pointer to ARC EMAC private data structure.
  32 *
  33 * returns: the number of slots available for transmission in tx the ring.
  34 */
  35static inline int arc_emac_tx_avail(struct arc_emac_priv *priv)
  36{
  37        return (priv->txbd_dirty + TX_BD_NUM - priv->txbd_curr - 1) % TX_BD_NUM;
  38}
  39
  40/**
  41 * arc_emac_adjust_link - Adjust the PHY link duplex.
  42 * @ndev:       Pointer to the net_device structure.
  43 *
  44 * This function is called to change the duplex setting after auto negotiation
  45 * is done by the PHY.
  46 */
  47static void arc_emac_adjust_link(struct net_device *ndev)
  48{
  49        struct arc_emac_priv *priv = netdev_priv(ndev);
  50        struct phy_device *phy_dev = priv->phy_dev;
  51        unsigned int reg, state_changed = 0;
  52
  53        if (priv->link != phy_dev->link) {
  54                priv->link = phy_dev->link;
  55                state_changed = 1;
  56        }
  57
  58        if (priv->speed != phy_dev->speed) {
  59                priv->speed = phy_dev->speed;
  60                state_changed = 1;
  61                if (priv->set_mac_speed)
  62                        priv->set_mac_speed(priv, priv->speed);
  63        }
  64
  65        if (priv->duplex != phy_dev->duplex) {
  66                reg = arc_reg_get(priv, R_CTRL);
  67
  68                if (phy_dev->duplex == DUPLEX_FULL)
  69                        reg |= ENFL_MASK;
  70                else
  71                        reg &= ~ENFL_MASK;
  72
  73                arc_reg_set(priv, R_CTRL, reg);
  74                priv->duplex = phy_dev->duplex;
  75                state_changed = 1;
  76        }
  77
  78        if (state_changed)
  79                phy_print_status(phy_dev);
  80}
  81
  82/**
  83 * arc_emac_get_settings - Get PHY settings.
  84 * @ndev:       Pointer to net_device structure.
  85 * @cmd:        Pointer to ethtool_cmd structure.
  86 *
  87 * This implements ethtool command for getting PHY settings. If PHY could
  88 * not be found, the function returns -ENODEV. This function calls the
  89 * relevant PHY ethtool API to get the PHY settings.
  90 * Issue "ethtool ethX" under linux prompt to execute this function.
  91 */
  92static int arc_emac_get_settings(struct net_device *ndev,
  93                                 struct ethtool_cmd *cmd)
  94{
  95        struct arc_emac_priv *priv = netdev_priv(ndev);
  96
  97        return phy_ethtool_gset(priv->phy_dev, cmd);
  98}
  99
 100/**
 101 * arc_emac_set_settings - Set PHY settings as passed in the argument.
 102 * @ndev:       Pointer to net_device structure.
 103 * @cmd:        Pointer to ethtool_cmd structure.
 104 *
 105 * This implements ethtool command for setting various PHY settings. If PHY
 106 * could not be found, the function returns -ENODEV. This function calls the
 107 * relevant PHY ethtool API to set the PHY.
 108 * Issue e.g. "ethtool -s ethX speed 1000" under linux prompt to execute this
 109 * function.
 110 */
 111static int arc_emac_set_settings(struct net_device *ndev,
 112                                 struct ethtool_cmd *cmd)
 113{
 114        struct arc_emac_priv *priv = netdev_priv(ndev);
 115
 116        if (!capable(CAP_NET_ADMIN))
 117                return -EPERM;
 118
 119        return phy_ethtool_sset(priv->phy_dev, cmd);
 120}
 121
 122/**
 123 * arc_emac_get_drvinfo - Get EMAC driver information.
 124 * @ndev:       Pointer to net_device structure.
 125 * @info:       Pointer to ethtool_drvinfo structure.
 126 *
 127 * This implements ethtool command for getting the driver information.
 128 * Issue "ethtool -i ethX" under linux prompt to execute this function.
 129 */
 130static void arc_emac_get_drvinfo(struct net_device *ndev,
 131                                 struct ethtool_drvinfo *info)
 132{
 133        struct arc_emac_priv *priv = netdev_priv(ndev);
 134
 135        strlcpy(info->driver, priv->drv_name, sizeof(info->driver));
 136        strlcpy(info->version, priv->drv_version, sizeof(info->version));
 137}
 138
 139static const struct ethtool_ops arc_emac_ethtool_ops = {
 140        .get_settings   = arc_emac_get_settings,
 141        .set_settings   = arc_emac_set_settings,
 142        .get_drvinfo    = arc_emac_get_drvinfo,
 143        .get_link       = ethtool_op_get_link,
 144};
 145
 146#define FIRST_OR_LAST_MASK      (FIRST_MASK | LAST_MASK)
 147
 148/**
 149 * arc_emac_tx_clean - clears processed by EMAC Tx BDs.
 150 * @ndev:       Pointer to the network device.
 151 */
 152static void arc_emac_tx_clean(struct net_device *ndev)
 153{
 154        struct arc_emac_priv *priv = netdev_priv(ndev);
 155        struct net_device_stats *stats = &ndev->stats;
 156        unsigned int i;
 157
 158        for (i = 0; i < TX_BD_NUM; i++) {
 159                unsigned int *txbd_dirty = &priv->txbd_dirty;
 160                struct arc_emac_bd *txbd = &priv->txbd[*txbd_dirty];
 161                struct buffer_state *tx_buff = &priv->tx_buff[*txbd_dirty];
 162                struct sk_buff *skb = tx_buff->skb;
 163                unsigned int info = le32_to_cpu(txbd->info);
 164
 165                if ((info & FOR_EMAC) || !txbd->data || !skb)
 166                        break;
 167
 168                if (unlikely(info & (DROP | DEFR | LTCL | UFLO))) {
 169                        stats->tx_errors++;
 170                        stats->tx_dropped++;
 171
 172                        if (info & DEFR)
 173                                stats->tx_carrier_errors++;
 174
 175                        if (info & LTCL)
 176                                stats->collisions++;
 177
 178                        if (info & UFLO)
 179                                stats->tx_fifo_errors++;
 180                } else if (likely(info & FIRST_OR_LAST_MASK)) {
 181                        stats->tx_packets++;
 182                        stats->tx_bytes += skb->len;
 183                }
 184
 185                dma_unmap_single(&ndev->dev, dma_unmap_addr(tx_buff, addr),
 186                                 dma_unmap_len(tx_buff, len), DMA_TO_DEVICE);
 187
 188                /* return the sk_buff to system */
 189                dev_kfree_skb_irq(skb);
 190
 191                txbd->data = 0;
 192                txbd->info = 0;
 193                tx_buff->skb = NULL;
 194
 195                *txbd_dirty = (*txbd_dirty + 1) % TX_BD_NUM;
 196        }
 197
 198        /* Ensure that txbd_dirty is visible to tx() before checking
 199         * for queue stopped.
 200         */
 201        smp_mb();
 202
 203        if (netif_queue_stopped(ndev) && arc_emac_tx_avail(priv))
 204                netif_wake_queue(ndev);
 205}
 206
 207/**
 208 * arc_emac_rx - processing of Rx packets.
 209 * @ndev:       Pointer to the network device.
 210 * @budget:     How many BDs to process on 1 call.
 211 *
 212 * returns:     Number of processed BDs
 213 *
 214 * Iterate through Rx BDs and deliver received packages to upper layer.
 215 */
 216static int arc_emac_rx(struct net_device *ndev, int budget)
 217{
 218        struct arc_emac_priv *priv = netdev_priv(ndev);
 219        unsigned int work_done;
 220
 221        for (work_done = 0; work_done < budget; work_done++) {
 222                unsigned int *last_rx_bd = &priv->last_rx_bd;
 223                struct net_device_stats *stats = &ndev->stats;
 224                struct buffer_state *rx_buff = &priv->rx_buff[*last_rx_bd];
 225                struct arc_emac_bd *rxbd = &priv->rxbd[*last_rx_bd];
 226                unsigned int pktlen, info = le32_to_cpu(rxbd->info);
 227                struct sk_buff *skb;
 228                dma_addr_t addr;
 229
 230                if (unlikely((info & OWN_MASK) == FOR_EMAC))
 231                        break;
 232
 233                /* Make a note that we saw a packet at this BD.
 234                 * So next time, driver starts from this + 1
 235                 */
 236                *last_rx_bd = (*last_rx_bd + 1) % RX_BD_NUM;
 237
 238                if (unlikely((info & FIRST_OR_LAST_MASK) !=
 239                             FIRST_OR_LAST_MASK)) {
 240                        /* We pre-allocate buffers of MTU size so incoming
 241                         * packets won't be split/chained.
 242                         */
 243                        if (net_ratelimit())
 244                                netdev_err(ndev, "incomplete packet received\n");
 245
 246                        /* Return ownership to EMAC */
 247                        rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
 248                        stats->rx_errors++;
 249                        stats->rx_length_errors++;
 250                        continue;
 251                }
 252
 253                pktlen = info & LEN_MASK;
 254                stats->rx_packets++;
 255                stats->rx_bytes += pktlen;
 256                skb = rx_buff->skb;
 257                skb_put(skb, pktlen);
 258                skb->dev = ndev;
 259                skb->protocol = eth_type_trans(skb, ndev);
 260
 261                dma_unmap_single(&ndev->dev, dma_unmap_addr(rx_buff, addr),
 262                                 dma_unmap_len(rx_buff, len), DMA_FROM_DEVICE);
 263
 264                /* Prepare the BD for next cycle */
 265                rx_buff->skb = netdev_alloc_skb_ip_align(ndev,
 266                                                         EMAC_BUFFER_SIZE);
 267                if (unlikely(!rx_buff->skb)) {
 268                        stats->rx_errors++;
 269                        /* Because receive_skb is below, increment rx_dropped */
 270                        stats->rx_dropped++;
 271                        continue;
 272                }
 273
 274                /* receive_skb only if new skb was allocated to avoid holes */
 275                netif_receive_skb(skb);
 276
 277                addr = dma_map_single(&ndev->dev, (void *)rx_buff->skb->data,
 278                                      EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
 279                if (dma_mapping_error(&ndev->dev, addr)) {
 280                        if (net_ratelimit())
 281                                netdev_err(ndev, "cannot dma map\n");
 282                        dev_kfree_skb(rx_buff->skb);
 283                        stats->rx_errors++;
 284                        continue;
 285                }
 286                dma_unmap_addr_set(rx_buff, addr, addr);
 287                dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);
 288
 289                rxbd->data = cpu_to_le32(addr);
 290
 291                /* Make sure pointer to data buffer is set */
 292                wmb();
 293
 294                /* Return ownership to EMAC */
 295                rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
 296        }
 297
 298        return work_done;
 299}
 300
 301/**
 302 * arc_emac_poll - NAPI poll handler.
 303 * @napi:       Pointer to napi_struct structure.
 304 * @budget:     How many BDs to process on 1 call.
 305 *
 306 * returns:     Number of processed BDs
 307 */
 308static int arc_emac_poll(struct napi_struct *napi, int budget)
 309{
 310        struct net_device *ndev = napi->dev;
 311        struct arc_emac_priv *priv = netdev_priv(ndev);
 312        unsigned int work_done;
 313
 314        arc_emac_tx_clean(ndev);
 315
 316        work_done = arc_emac_rx(ndev, budget);
 317        if (work_done < budget) {
 318                napi_complete(napi);
 319                arc_reg_or(priv, R_ENABLE, RXINT_MASK | TXINT_MASK);
 320        }
 321
 322        return work_done;
 323}
 324
 325/**
 326 * arc_emac_intr - Global interrupt handler for EMAC.
 327 * @irq:                irq number.
 328 * @dev_instance:       device instance.
 329 *
 330 * returns: IRQ_HANDLED for all cases.
 331 *
 332 * ARC EMAC has only 1 interrupt line, and depending on bits raised in
 333 * STATUS register we may tell what is a reason for interrupt to fire.
 334 */
 335static irqreturn_t arc_emac_intr(int irq, void *dev_instance)
 336{
 337        struct net_device *ndev = dev_instance;
 338        struct arc_emac_priv *priv = netdev_priv(ndev);
 339        struct net_device_stats *stats = &ndev->stats;
 340        unsigned int status;
 341
 342        status = arc_reg_get(priv, R_STATUS);
 343        status &= ~MDIO_MASK;
 344
 345        /* Reset all flags except "MDIO complete" */
 346        arc_reg_set(priv, R_STATUS, status);
 347
 348        if (status & (RXINT_MASK | TXINT_MASK)) {
 349                if (likely(napi_schedule_prep(&priv->napi))) {
 350                        arc_reg_clr(priv, R_ENABLE, RXINT_MASK | TXINT_MASK);
 351                        __napi_schedule(&priv->napi);
 352                }
 353        }
 354
 355        if (status & ERR_MASK) {
 356                /* MSER/RXCR/RXFR/RXFL interrupt fires on corresponding
 357                 * 8-bit error counter overrun.
 358                 */
 359
 360                if (status & MSER_MASK) {
 361                        stats->rx_missed_errors += 0x100;
 362                        stats->rx_errors += 0x100;
 363                }
 364
 365                if (status & RXCR_MASK) {
 366                        stats->rx_crc_errors += 0x100;
 367                        stats->rx_errors += 0x100;
 368                }
 369
 370                if (status & RXFR_MASK) {
 371                        stats->rx_frame_errors += 0x100;
 372                        stats->rx_errors += 0x100;
 373                }
 374
 375                if (status & RXFL_MASK) {
 376                        stats->rx_over_errors += 0x100;
 377                        stats->rx_errors += 0x100;
 378                }
 379        }
 380
 381        return IRQ_HANDLED;
 382}
 383
 384#ifdef CONFIG_NET_POLL_CONTROLLER
 385static void arc_emac_poll_controller(struct net_device *dev)
 386{
 387        disable_irq(dev->irq);
 388        arc_emac_intr(dev->irq, dev);
 389        enable_irq(dev->irq);
 390}
 391#endif
 392
 393/**
 394 * arc_emac_open - Open the network device.
 395 * @ndev:       Pointer to the network device.
 396 *
 397 * returns: 0, on success or non-zero error value on failure.
 398 *
 399 * This function sets the MAC address, requests and enables an IRQ
 400 * for the EMAC device and starts the Tx queue.
 401 * It also connects to the phy device.
 402 */
 403static int arc_emac_open(struct net_device *ndev)
 404{
 405        struct arc_emac_priv *priv = netdev_priv(ndev);
 406        struct phy_device *phy_dev = priv->phy_dev;
 407        int i;
 408
 409        phy_dev->autoneg = AUTONEG_ENABLE;
 410        phy_dev->speed = 0;
 411        phy_dev->duplex = 0;
 412        phy_dev->advertising &= phy_dev->supported;
 413
 414        priv->last_rx_bd = 0;
 415
 416        /* Allocate and set buffers for Rx BD's */
 417        for (i = 0; i < RX_BD_NUM; i++) {
 418                dma_addr_t addr;
 419                unsigned int *last_rx_bd = &priv->last_rx_bd;
 420                struct arc_emac_bd *rxbd = &priv->rxbd[*last_rx_bd];
 421                struct buffer_state *rx_buff = &priv->rx_buff[*last_rx_bd];
 422
 423                rx_buff->skb = netdev_alloc_skb_ip_align(ndev,
 424                                                         EMAC_BUFFER_SIZE);
 425                if (unlikely(!rx_buff->skb))
 426                        return -ENOMEM;
 427
 428                addr = dma_map_single(&ndev->dev, (void *)rx_buff->skb->data,
 429                                      EMAC_BUFFER_SIZE, DMA_FROM_DEVICE);
 430                if (dma_mapping_error(&ndev->dev, addr)) {
 431                        netdev_err(ndev, "cannot dma map\n");
 432                        dev_kfree_skb(rx_buff->skb);
 433                        return -ENOMEM;
 434                }
 435                dma_unmap_addr_set(rx_buff, addr, addr);
 436                dma_unmap_len_set(rx_buff, len, EMAC_BUFFER_SIZE);
 437
 438                rxbd->data = cpu_to_le32(addr);
 439
 440                /* Make sure pointer to data buffer is set */
 441                wmb();
 442
 443                /* Return ownership to EMAC */
 444                rxbd->info = cpu_to_le32(FOR_EMAC | EMAC_BUFFER_SIZE);
 445
 446                *last_rx_bd = (*last_rx_bd + 1) % RX_BD_NUM;
 447        }
 448
 449        priv->txbd_curr = 0;
 450        priv->txbd_dirty = 0;
 451
 452        /* Clean Tx BD's */
 453        memset(priv->txbd, 0, TX_RING_SZ);
 454
 455        /* Initialize logical address filter */
 456        arc_reg_set(priv, R_LAFL, 0);
 457        arc_reg_set(priv, R_LAFH, 0);
 458
 459        /* Set BD ring pointers for device side */
 460        arc_reg_set(priv, R_RX_RING, (unsigned int)priv->rxbd_dma);
 461        arc_reg_set(priv, R_TX_RING, (unsigned int)priv->txbd_dma);
 462
 463        /* Enable interrupts */
 464        arc_reg_set(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);
 465
 466        /* Set CONTROL */
 467        arc_reg_set(priv, R_CTRL,
 468                    (RX_BD_NUM << 24) | /* RX BD table length */
 469                    (TX_BD_NUM << 16) | /* TX BD table length */
 470                    TXRN_MASK | RXRN_MASK);
 471
 472        napi_enable(&priv->napi);
 473
 474        /* Enable EMAC */
 475        arc_reg_or(priv, R_CTRL, EN_MASK);
 476
 477        phy_start_aneg(priv->phy_dev);
 478
 479        netif_start_queue(ndev);
 480
 481        return 0;
 482}
 483
 484/**
 485 * arc_emac_set_rx_mode - Change the receive filtering mode.
 486 * @ndev:       Pointer to the network device.
 487 *
 488 * This function enables/disables promiscuous or all-multicast mode
 489 * and updates the multicast filtering list of the network device.
 490 */
 491static void arc_emac_set_rx_mode(struct net_device *ndev)
 492{
 493        struct arc_emac_priv *priv = netdev_priv(ndev);
 494
 495        if (ndev->flags & IFF_PROMISC) {
 496                arc_reg_or(priv, R_CTRL, PROM_MASK);
 497        } else {
 498                arc_reg_clr(priv, R_CTRL, PROM_MASK);
 499
 500                if (ndev->flags & IFF_ALLMULTI) {
 501                        arc_reg_set(priv, R_LAFL, ~0);
 502                        arc_reg_set(priv, R_LAFH, ~0);
 503                } else {
 504                        struct netdev_hw_addr *ha;
 505                        unsigned int filter[2] = { 0, 0 };
 506                        int bit;
 507
 508                        netdev_for_each_mc_addr(ha, ndev) {
 509                                bit = ether_crc_le(ETH_ALEN, ha->addr) >> 26;
 510                                filter[bit >> 5] |= 1 << (bit & 31);
 511                        }
 512
 513                        arc_reg_set(priv, R_LAFL, filter[0]);
 514                        arc_reg_set(priv, R_LAFH, filter[1]);
 515                }
 516        }
 517}
 518
 519/**
 520 * arc_free_tx_queue - free skb from tx queue
 521 * @ndev:       Pointer to the network device.
 522 *
 523 * This function must be called while EMAC disable
 524 */
 525static void arc_free_tx_queue(struct net_device *ndev)
 526{
 527        struct arc_emac_priv *priv = netdev_priv(ndev);
 528        unsigned int i;
 529
 530        for (i = 0; i < TX_BD_NUM; i++) {
 531                struct arc_emac_bd *txbd = &priv->txbd[i];
 532                struct buffer_state *tx_buff = &priv->tx_buff[i];
 533
 534                if (tx_buff->skb) {
 535                        dma_unmap_single(&ndev->dev,
 536                                         dma_unmap_addr(tx_buff, addr),
 537                                         dma_unmap_len(tx_buff, len),
 538                                         DMA_TO_DEVICE);
 539
 540                        /* return the sk_buff to system */
 541                        dev_kfree_skb_irq(tx_buff->skb);
 542                }
 543
 544                txbd->info = 0;
 545                txbd->data = 0;
 546                tx_buff->skb = NULL;
 547        }
 548}
 549
 550/**
 551 * arc_free_rx_queue - free skb from rx queue
 552 * @ndev:       Pointer to the network device.
 553 *
 554 * This function must be called while EMAC disable
 555 */
 556static void arc_free_rx_queue(struct net_device *ndev)
 557{
 558        struct arc_emac_priv *priv = netdev_priv(ndev);
 559        unsigned int i;
 560
 561        for (i = 0; i < RX_BD_NUM; i++) {
 562                struct arc_emac_bd *rxbd = &priv->rxbd[i];
 563                struct buffer_state *rx_buff = &priv->rx_buff[i];
 564
 565                if (rx_buff->skb) {
 566                        dma_unmap_single(&ndev->dev,
 567                                         dma_unmap_addr(rx_buff, addr),
 568                                         dma_unmap_len(rx_buff, len),
 569                                         DMA_FROM_DEVICE);
 570
 571                        /* return the sk_buff to system */
 572                        dev_kfree_skb_irq(rx_buff->skb);
 573                }
 574
 575                rxbd->info = 0;
 576                rxbd->data = 0;
 577                rx_buff->skb = NULL;
 578        }
 579}
 580
 581/**
 582 * arc_emac_stop - Close the network device.
 583 * @ndev:       Pointer to the network device.
 584 *
 585 * This function stops the Tx queue, disables interrupts and frees the IRQ for
 586 * the EMAC device.
 587 * It also disconnects the PHY device associated with the EMAC device.
 588 */
 589static int arc_emac_stop(struct net_device *ndev)
 590{
 591        struct arc_emac_priv *priv = netdev_priv(ndev);
 592
 593        napi_disable(&priv->napi);
 594        netif_stop_queue(ndev);
 595
 596        /* Disable interrupts */
 597        arc_reg_clr(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);
 598
 599        /* Disable EMAC */
 600        arc_reg_clr(priv, R_CTRL, EN_MASK);
 601
 602        /* Return the sk_buff to system */
 603        arc_free_tx_queue(ndev);
 604        arc_free_rx_queue(ndev);
 605
 606        return 0;
 607}
 608
 609/**
 610 * arc_emac_stats - Get system network statistics.
 611 * @ndev:       Pointer to net_device structure.
 612 *
 613 * Returns the address of the device statistics structure.
 614 * Statistics are updated in interrupt handler.
 615 */
 616static struct net_device_stats *arc_emac_stats(struct net_device *ndev)
 617{
 618        struct arc_emac_priv *priv = netdev_priv(ndev);
 619        struct net_device_stats *stats = &ndev->stats;
 620        unsigned long miss, rxerr;
 621        u8 rxcrc, rxfram, rxoflow;
 622
 623        rxerr = arc_reg_get(priv, R_RXERR);
 624        miss = arc_reg_get(priv, R_MISS);
 625
 626        rxcrc = rxerr;
 627        rxfram = rxerr >> 8;
 628        rxoflow = rxerr >> 16;
 629
 630        stats->rx_errors += miss;
 631        stats->rx_errors += rxcrc + rxfram + rxoflow;
 632
 633        stats->rx_over_errors += rxoflow;
 634        stats->rx_frame_errors += rxfram;
 635        stats->rx_crc_errors += rxcrc;
 636        stats->rx_missed_errors += miss;
 637
 638        return stats;
 639}
 640
 641/**
 642 * arc_emac_tx - Starts the data transmission.
 643 * @skb:        sk_buff pointer that contains data to be Transmitted.
 644 * @ndev:       Pointer to net_device structure.
 645 *
 646 * returns: NETDEV_TX_OK, on success
 647 *              NETDEV_TX_BUSY, if any of the descriptors are not free.
 648 *
 649 * This function is invoked from upper layers to initiate transmission.
 650 */
 651static int arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
 652{
 653        struct arc_emac_priv *priv = netdev_priv(ndev);
 654        unsigned int len, *txbd_curr = &priv->txbd_curr;
 655        struct net_device_stats *stats = &ndev->stats;
 656        __le32 *info = &priv->txbd[*txbd_curr].info;
 657        dma_addr_t addr;
 658
 659        if (skb_padto(skb, ETH_ZLEN))
 660                return NETDEV_TX_OK;
 661
 662        len = max_t(unsigned int, ETH_ZLEN, skb->len);
 663
 664        if (unlikely(!arc_emac_tx_avail(priv))) {
 665                netif_stop_queue(ndev);
 666                netdev_err(ndev, "BUG! Tx Ring full when queue awake!\n");
 667                return NETDEV_TX_BUSY;
 668        }
 669
 670        addr = dma_map_single(&ndev->dev, (void *)skb->data, len,
 671                              DMA_TO_DEVICE);
 672
 673        if (unlikely(dma_mapping_error(&ndev->dev, addr))) {
 674                stats->tx_dropped++;
 675                stats->tx_errors++;
 676                dev_kfree_skb(skb);
 677                return NETDEV_TX_OK;
 678        }
 679        dma_unmap_addr_set(&priv->tx_buff[*txbd_curr], addr, addr);
 680        dma_unmap_len_set(&priv->tx_buff[*txbd_curr], len, len);
 681
 682        priv->txbd[*txbd_curr].data = cpu_to_le32(addr);
 683
 684        /* Make sure pointer to data buffer is set */
 685        wmb();
 686
 687        skb_tx_timestamp(skb);
 688
 689        *info = cpu_to_le32(FOR_EMAC | FIRST_OR_LAST_MASK | len);
 690
 691        /* Make sure info word is set */
 692        wmb();
 693
 694        priv->tx_buff[*txbd_curr].skb = skb;
 695
 696        /* Increment index to point to the next BD */
 697        *txbd_curr = (*txbd_curr + 1) % TX_BD_NUM;
 698
 699        /* Ensure that tx_clean() sees the new txbd_curr before
 700         * checking the queue status. This prevents an unneeded wake
 701         * of the queue in tx_clean().
 702         */
 703        smp_mb();
 704
 705        if (!arc_emac_tx_avail(priv)) {
 706                netif_stop_queue(ndev);
 707                /* Refresh tx_dirty */
 708                smp_mb();
 709                if (arc_emac_tx_avail(priv))
 710                        netif_start_queue(ndev);
 711        }
 712
 713        arc_reg_set(priv, R_STATUS, TXPL_MASK);
 714
 715        return NETDEV_TX_OK;
 716}
 717
 718static void arc_emac_set_address_internal(struct net_device *ndev)
 719{
 720        struct arc_emac_priv *priv = netdev_priv(ndev);
 721        unsigned int addr_low, addr_hi;
 722
 723        addr_low = le32_to_cpu(*(__le32 *)&ndev->dev_addr[0]);
 724        addr_hi = le16_to_cpu(*(__le16 *)&ndev->dev_addr[4]);
 725
 726        arc_reg_set(priv, R_ADDRL, addr_low);
 727        arc_reg_set(priv, R_ADDRH, addr_hi);
 728}
 729
 730/**
 731 * arc_emac_set_address - Set the MAC address for this device.
 732 * @ndev:       Pointer to net_device structure.
 733 * @p:          6 byte Address to be written as MAC address.
 734 *
 735 * This function copies the HW address from the sockaddr structure to the
 736 * net_device structure and updates the address in HW.
 737 *
 738 * returns:     -EBUSY if the net device is busy or 0 if the address is set
 739 *              successfully.
 740 */
 741static int arc_emac_set_address(struct net_device *ndev, void *p)
 742{
 743        struct sockaddr *addr = p;
 744
 745        if (netif_running(ndev))
 746                return -EBUSY;
 747
 748        if (!is_valid_ether_addr(addr->sa_data))
 749                return -EADDRNOTAVAIL;
 750
 751        memcpy(ndev->dev_addr, addr->sa_data, ndev->addr_len);
 752
 753        arc_emac_set_address_internal(ndev);
 754
 755        return 0;
 756}
 757
 758static const struct net_device_ops arc_emac_netdev_ops = {
 759        .ndo_open               = arc_emac_open,
 760        .ndo_stop               = arc_emac_stop,
 761        .ndo_start_xmit         = arc_emac_tx,
 762        .ndo_set_mac_address    = arc_emac_set_address,
 763        .ndo_get_stats          = arc_emac_stats,
 764        .ndo_set_rx_mode        = arc_emac_set_rx_mode,
 765#ifdef CONFIG_NET_POLL_CONTROLLER
 766        .ndo_poll_controller    = arc_emac_poll_controller,
 767#endif
 768};
 769
 770int arc_emac_probe(struct net_device *ndev, int interface)
 771{
 772        struct device *dev = ndev->dev.parent;
 773        struct resource res_regs;
 774        struct device_node *phy_node;
 775        struct arc_emac_priv *priv;
 776        const char *mac_addr;
 777        unsigned int id, clock_frequency, irq;
 778        int err;
 779
 780        /* Get PHY from device tree */
 781        phy_node = of_parse_phandle(dev->of_node, "phy", 0);
 782        if (!phy_node) {
 783                dev_err(dev, "failed to retrieve phy description from device tree\n");
 784                return -ENODEV;
 785        }
 786
 787        /* Get EMAC registers base address from device tree */
 788        err = of_address_to_resource(dev->of_node, 0, &res_regs);
 789        if (err) {
 790                dev_err(dev, "failed to retrieve registers base from device tree\n");
 791                return -ENODEV;
 792        }
 793
 794        /* Get IRQ from device tree */
 795        irq = irq_of_parse_and_map(dev->of_node, 0);
 796        if (!irq) {
 797                dev_err(dev, "failed to retrieve <irq> value from device tree\n");
 798                return -ENODEV;
 799        }
 800
 801        ndev->netdev_ops = &arc_emac_netdev_ops;
 802        ndev->ethtool_ops = &arc_emac_ethtool_ops;
 803        ndev->watchdog_timeo = TX_TIMEOUT;
 804        /* FIXME :: no multicast support yet */
 805        ndev->flags &= ~IFF_MULTICAST;
 806
 807        priv = netdev_priv(ndev);
 808        priv->dev = dev;
 809
 810        priv->regs = devm_ioremap_resource(dev, &res_regs);
 811        if (IS_ERR(priv->regs))
 812                return PTR_ERR(priv->regs);
 813
 814        dev_dbg(dev, "Registers base address is 0x%p\n", priv->regs);
 815
 816        if (priv->clk) {
 817                err = clk_prepare_enable(priv->clk);
 818                if (err) {
 819                        dev_err(dev, "failed to enable clock\n");
 820                        return err;
 821                }
 822
 823                clock_frequency = clk_get_rate(priv->clk);
 824        } else {
 825                /* Get CPU clock frequency from device tree */
 826                if (of_property_read_u32(dev->of_node, "clock-frequency",
 827                                         &clock_frequency)) {
 828                        dev_err(dev, "failed to retrieve <clock-frequency> from device tree\n");
 829                        return -EINVAL;
 830                }
 831        }
 832
 833        id = arc_reg_get(priv, R_ID);
 834
 835        /* Check for EMAC revision 5 or 7, magic number */
 836        if (!(id == 0x0005fd02 || id == 0x0007fd02)) {
 837                dev_err(dev, "ARC EMAC not detected, id=0x%x\n", id);
 838                err = -ENODEV;
 839                goto out_clken;
 840        }
 841        dev_info(dev, "ARC EMAC detected with id: 0x%x\n", id);
 842
 843        /* Set poll rate so that it polls every 1 ms */
 844        arc_reg_set(priv, R_POLLRATE, clock_frequency / 1000000);
 845
 846        ndev->irq = irq;
 847        dev_info(dev, "IRQ is %d\n", ndev->irq);
 848
 849        /* Register interrupt handler for device */
 850        err = devm_request_irq(dev, ndev->irq, arc_emac_intr, 0,
 851                               ndev->name, ndev);
 852        if (err) {
 853                dev_err(dev, "could not allocate IRQ\n");
 854                goto out_clken;
 855        }
 856
 857        /* Get MAC address from device tree */
 858        mac_addr = of_get_mac_address(dev->of_node);
 859
 860        if (mac_addr)
 861                memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);
 862        else
 863                eth_hw_addr_random(ndev);
 864
 865        arc_emac_set_address_internal(ndev);
 866        dev_info(dev, "MAC address is now %pM\n", ndev->dev_addr);
 867
 868        /* Do 1 allocation instead of 2 separate ones for Rx and Tx BD rings */
 869        priv->rxbd = dmam_alloc_coherent(dev, RX_RING_SZ + TX_RING_SZ,
 870                                         &priv->rxbd_dma, GFP_KERNEL);
 871
 872        if (!priv->rxbd) {
 873                dev_err(dev, "failed to allocate data buffers\n");
 874                err = -ENOMEM;
 875                goto out_clken;
 876        }
 877
 878        priv->txbd = priv->rxbd + RX_BD_NUM;
 879
 880        priv->txbd_dma = priv->rxbd_dma + RX_RING_SZ;
 881        dev_dbg(dev, "EMAC Device addr: Rx Ring [0x%x], Tx Ring[%x]\n",
 882                (unsigned int)priv->rxbd_dma, (unsigned int)priv->txbd_dma);
 883
 884        err = arc_mdio_probe(priv);
 885        if (err) {
 886                dev_err(dev, "failed to probe MII bus\n");
 887                goto out_clken;
 888        }
 889
 890        priv->phy_dev = of_phy_connect(ndev, phy_node, arc_emac_adjust_link, 0,
 891                                       interface);
 892        if (!priv->phy_dev) {
 893                dev_err(dev, "of_phy_connect() failed\n");
 894                err = -ENODEV;
 895                goto out_mdio;
 896        }
 897
 898        dev_info(dev, "connected to %s phy with id 0x%x\n",
 899                 priv->phy_dev->drv->name, priv->phy_dev->phy_id);
 900
 901        netif_napi_add(ndev, &priv->napi, arc_emac_poll, ARC_EMAC_NAPI_WEIGHT);
 902
 903        err = register_netdev(ndev);
 904        if (err) {
 905                dev_err(dev, "failed to register network device\n");
 906                goto out_netif_api;
 907        }
 908
 909        return 0;
 910
 911out_netif_api:
 912        netif_napi_del(&priv->napi);
 913        phy_disconnect(priv->phy_dev);
 914        priv->phy_dev = NULL;
 915out_mdio:
 916        arc_mdio_remove(priv);
 917out_clken:
 918        if (priv->clk)
 919                clk_disable_unprepare(priv->clk);
 920        return err;
 921}
 922EXPORT_SYMBOL_GPL(arc_emac_probe);
 923
 924int arc_emac_remove(struct net_device *ndev)
 925{
 926        struct arc_emac_priv *priv = netdev_priv(ndev);
 927
 928        phy_disconnect(priv->phy_dev);
 929        priv->phy_dev = NULL;
 930        arc_mdio_remove(priv);
 931        unregister_netdev(ndev);
 932        netif_napi_del(&priv->napi);
 933
 934        if (!IS_ERR(priv->clk))
 935                clk_disable_unprepare(priv->clk);
 936
 937        return 0;
 938}
 939EXPORT_SYMBOL_GPL(arc_emac_remove);
 940
 941MODULE_AUTHOR("Alexey Brodkin <abrodkin@synopsys.com>");
 942MODULE_DESCRIPTION("ARC EMAC driver");
 943MODULE_LICENSE("GPL");
 944
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