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