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/**
  31 * arc_emac_tx_avail - Return the number of available slots in the tx ring.
  32 * @priv: Pointer to ARC EMAC private data structure.
  33 *
  34 * returns: the number of slots available for transmission in tx the ring.
  35 */
  36static inline int arc_emac_tx_avail(struct arc_emac_priv *priv)
  37{
  38        return (priv->txbd_dirty + TX_BD_NUM - priv->txbd_curr - 1) % TX_BD_NUM;
  39}
  40
  41/**
  42 * arc_emac_adjust_link - Adjust the PHY link duplex.
  43 * @ndev:       Pointer to the net_device structure.
  44 *
  45 * This function is called to change the duplex setting after auto negotiation
  46 * is done by the PHY.
  47 */
  48static void arc_emac_adjust_link(struct net_device *ndev)
  49{
  50        struct arc_emac_priv *priv = netdev_priv(ndev);
  51        struct phy_device *phy_dev = priv->phy_dev;
  52        unsigned int reg, state_changed = 0;
  53
  54        if (priv->link != phy_dev->link) {
  55                priv->link = phy_dev->link;
  56                state_changed = 1;
  57        }
  58
  59        if (priv->speed != phy_dev->speed) {
  60                priv->speed = phy_dev->speed;
  61                state_changed = 1;
  62                if (priv->set_mac_speed)
  63                        priv->set_mac_speed(priv, priv->speed);
  64        }
  65
  66        if (priv->duplex != phy_dev->duplex) {
  67                reg = arc_reg_get(priv, R_CTRL);
  68
  69                if (DUPLEX_FULL == phy_dev->duplex)
  70                        reg |= ENFL_MASK;
  71                else
  72                        reg &= ~ENFL_MASK;
  73
  74                arc_reg_set(priv, R_CTRL, reg);
  75                priv->duplex = phy_dev->duplex;
  76                state_changed = 1;
  77        }
  78
  79        if (state_changed)
  80                phy_print_status(phy_dev);
  81}
  82
  83/**
  84 * arc_emac_get_settings - Get PHY settings.
  85 * @ndev:       Pointer to net_device structure.
  86 * @cmd:        Pointer to ethtool_cmd structure.
  87 *
  88 * This implements ethtool command for getting PHY settings. If PHY could
  89 * not be found, the function returns -ENODEV. This function calls the
  90 * relevant PHY ethtool API to get the PHY settings.
  91 * Issue "ethtool ethX" under linux prompt to execute this function.
  92 */
  93static int arc_emac_get_settings(struct net_device *ndev,
  94                                 struct ethtool_cmd *cmd)
  95{
  96        struct arc_emac_priv *priv = netdev_priv(ndev);
  97
  98        return phy_ethtool_gset(priv->phy_dev, cmd);
  99}
 100
 101/**
 102 * arc_emac_set_settings - Set PHY settings as passed in the argument.
 103 * @ndev:       Pointer to net_device structure.
 104 * @cmd:        Pointer to ethtool_cmd structure.
 105 *
 106 * This implements ethtool command for setting various PHY settings. If PHY
 107 * could not be found, the function returns -ENODEV. This function calls the
 108 * relevant PHY ethtool API to set the PHY.
 109 * Issue e.g. "ethtool -s ethX speed 1000" under linux prompt to execute this
 110 * function.
 111 */
 112static int arc_emac_set_settings(struct net_device *ndev,
 113                                 struct ethtool_cmd *cmd)
 114{
 115        struct arc_emac_priv *priv = netdev_priv(ndev);
 116
 117        if (!capable(CAP_NET_ADMIN))
 118                return -EPERM;
 119
 120        return phy_ethtool_sset(priv->phy_dev, cmd);
 121}
 122
 123/**
 124 * arc_emac_get_drvinfo - Get EMAC driver information.
 125 * @ndev:       Pointer to net_device structure.
 126 * @info:       Pointer to ethtool_drvinfo structure.
 127 *
 128 * This implements ethtool command for getting the driver information.
 129 * Issue "ethtool -i ethX" under linux prompt to execute this function.
 130 */
 131static void arc_emac_get_drvinfo(struct net_device *ndev,
 132                                 struct ethtool_drvinfo *info)
 133{
 134        struct arc_emac_priv *priv = netdev_priv(ndev);
 135
 136        strlcpy(info->driver, priv->drv_name, sizeof(info->driver));
 137        strlcpy(info->version, priv->drv_version, sizeof(info->version));
 138}
 139
 140static const struct ethtool_ops arc_emac_ethtool_ops = {
 141        .get_settings   = arc_emac_get_settings,
 142        .set_settings   = arc_emac_set_settings,
 143        .get_drvinfo    = arc_emac_get_drvinfo,
 144        .get_link       = ethtool_op_get_link,
 145};
 146
 147#define FIRST_OR_LAST_MASK      (FIRST_MASK | LAST_MASK)
 148
 149/**
 150 * arc_emac_tx_clean - clears processed by EMAC Tx BDs.
 151 * @ndev:       Pointer to the network device.
 152 */
 153static void arc_emac_tx_clean(struct net_device *ndev)
 154{
 155        struct arc_emac_priv *priv = netdev_priv(ndev);
 156        struct net_device_stats *stats = &ndev->stats;
 157        unsigned int i;
 158
 159        for (i = 0; i < TX_BD_NUM; i++) {
 160                unsigned int *txbd_dirty = &priv->txbd_dirty;
 161                struct arc_emac_bd *txbd = &priv->txbd[*txbd_dirty];
 162                struct buffer_state *tx_buff = &priv->tx_buff[*txbd_dirty];
 163                struct sk_buff *skb = tx_buff->skb;
 164                unsigned int info = le32_to_cpu(txbd->info);
 165
 166                if ((info & FOR_EMAC) || !txbd->data)
 167                        break;
 168
 169                if (unlikely(info & (DROP | DEFR | LTCL | UFLO))) {
 170                        stats->tx_errors++;
 171                        stats->tx_dropped++;
 172
 173                        if (info & DEFR)
 174                                stats->tx_carrier_errors++;
 175
 176                        if (info & LTCL)
 177                                stats->collisions++;
 178
 179                        if (info & UFLO)
 180                                stats->tx_fifo_errors++;
 181                } else if (likely(info & FIRST_OR_LAST_MASK)) {
 182                        stats->tx_packets++;
 183                        stats->tx_bytes += skb->len;
 184                }
 185
 186                dma_unmap_single(&ndev->dev, dma_unmap_addr(tx_buff, addr),
 187                                 dma_unmap_len(tx_buff, len), DMA_TO_DEVICE);
 188
 189                /* return the sk_buff to system */
 190                dev_kfree_skb_irq(skb);
 191
 192                txbd->data = 0;
 193                txbd->info = 0;
 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        /* Clean Tx BD's */
 450        memset(priv->txbd, 0, TX_RING_SZ);
 451
 452        /* Initialize logical address filter */
 453        arc_reg_set(priv, R_LAFL, 0);
 454        arc_reg_set(priv, R_LAFH, 0);
 455
 456        /* Set BD ring pointers for device side */
 457        arc_reg_set(priv, R_RX_RING, (unsigned int)priv->rxbd_dma);
 458        arc_reg_set(priv, R_TX_RING, (unsigned int)priv->txbd_dma);
 459
 460        /* Enable interrupts */
 461        arc_reg_set(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);
 462
 463        /* Set CONTROL */
 464        arc_reg_set(priv, R_CTRL,
 465                     (RX_BD_NUM << 24) |        /* RX BD table length */
 466                     (TX_BD_NUM << 16) |        /* TX BD table length */
 467                     TXRN_MASK | RXRN_MASK);
 468
 469        napi_enable(&priv->napi);
 470
 471        /* Enable EMAC */
 472        arc_reg_or(priv, R_CTRL, EN_MASK);
 473
 474        phy_start_aneg(priv->phy_dev);
 475
 476        netif_start_queue(ndev);
 477
 478        return 0;
 479}
 480
 481/**
 482 * arc_emac_set_rx_mode - Change the receive filtering mode.
 483 * @ndev:       Pointer to the network device.
 484 *
 485 * This function enables/disables promiscuous or all-multicast mode
 486 * and updates the multicast filtering list of the network device.
 487 */
 488static void arc_emac_set_rx_mode(struct net_device *ndev)
 489{
 490        struct arc_emac_priv *priv = netdev_priv(ndev);
 491
 492        if (ndev->flags & IFF_PROMISC) {
 493                arc_reg_or(priv, R_CTRL, PROM_MASK);
 494        } else {
 495                arc_reg_clr(priv, R_CTRL, PROM_MASK);
 496
 497                if (ndev->flags & IFF_ALLMULTI) {
 498                        arc_reg_set(priv, R_LAFL, ~0);
 499                        arc_reg_set(priv, R_LAFH, ~0);
 500                } else {
 501                        struct netdev_hw_addr *ha;
 502                        unsigned int filter[2] = { 0, 0 };
 503                        int bit;
 504
 505                        netdev_for_each_mc_addr(ha, ndev) {
 506                                bit = ether_crc_le(ETH_ALEN, ha->addr) >> 26;
 507                                filter[bit >> 5] |= 1 << (bit & 31);
 508                        }
 509
 510                        arc_reg_set(priv, R_LAFL, filter[0]);
 511                        arc_reg_set(priv, R_LAFH, filter[1]);
 512                }
 513        }
 514}
 515
 516/**
 517 * arc_emac_stop - Close the network device.
 518 * @ndev:       Pointer to the network device.
 519 *
 520 * This function stops the Tx queue, disables interrupts and frees the IRQ for
 521 * the EMAC device.
 522 * It also disconnects the PHY device associated with the EMAC device.
 523 */
 524static int arc_emac_stop(struct net_device *ndev)
 525{
 526        struct arc_emac_priv *priv = netdev_priv(ndev);
 527
 528        napi_disable(&priv->napi);
 529        netif_stop_queue(ndev);
 530
 531        /* Disable interrupts */
 532        arc_reg_clr(priv, R_ENABLE, RXINT_MASK | TXINT_MASK | ERR_MASK);
 533
 534        /* Disable EMAC */
 535        arc_reg_clr(priv, R_CTRL, EN_MASK);
 536
 537        return 0;
 538}
 539
 540/**
 541 * arc_emac_stats - Get system network statistics.
 542 * @ndev:       Pointer to net_device structure.
 543 *
 544 * Returns the address of the device statistics structure.
 545 * Statistics are updated in interrupt handler.
 546 */
 547static struct net_device_stats *arc_emac_stats(struct net_device *ndev)
 548{
 549        struct arc_emac_priv *priv = netdev_priv(ndev);
 550        struct net_device_stats *stats = &ndev->stats;
 551        unsigned long miss, rxerr;
 552        u8 rxcrc, rxfram, rxoflow;
 553
 554        rxerr = arc_reg_get(priv, R_RXERR);
 555        miss = arc_reg_get(priv, R_MISS);
 556
 557        rxcrc = rxerr;
 558        rxfram = rxerr >> 8;
 559        rxoflow = rxerr >> 16;
 560
 561        stats->rx_errors += miss;
 562        stats->rx_errors += rxcrc + rxfram + rxoflow;
 563
 564        stats->rx_over_errors += rxoflow;
 565        stats->rx_frame_errors += rxfram;
 566        stats->rx_crc_errors += rxcrc;
 567        stats->rx_missed_errors += miss;
 568
 569        return stats;
 570}
 571
 572/**
 573 * arc_emac_tx - Starts the data transmission.
 574 * @skb:        sk_buff pointer that contains data to be Transmitted.
 575 * @ndev:       Pointer to net_device structure.
 576 *
 577 * returns: NETDEV_TX_OK, on success
 578 *              NETDEV_TX_BUSY, if any of the descriptors are not free.
 579 *
 580 * This function is invoked from upper layers to initiate transmission.
 581 */
 582static int arc_emac_tx(struct sk_buff *skb, struct net_device *ndev)
 583{
 584        struct arc_emac_priv *priv = netdev_priv(ndev);
 585        unsigned int len, *txbd_curr = &priv->txbd_curr;
 586        struct net_device_stats *stats = &ndev->stats;
 587        __le32 *info = &priv->txbd[*txbd_curr].info;
 588        dma_addr_t addr;
 589
 590        if (skb_padto(skb, ETH_ZLEN))
 591                return NETDEV_TX_OK;
 592
 593        len = max_t(unsigned int, ETH_ZLEN, skb->len);
 594
 595        if (unlikely(!arc_emac_tx_avail(priv))) {
 596                netif_stop_queue(ndev);
 597                netdev_err(ndev, "BUG! Tx Ring full when queue awake!\n");
 598                return NETDEV_TX_BUSY;
 599        }
 600
 601        addr = dma_map_single(&ndev->dev, (void *)skb->data, len,
 602                              DMA_TO_DEVICE);
 603
 604        if (unlikely(dma_mapping_error(&ndev->dev, addr))) {
 605                stats->tx_dropped++;
 606                stats->tx_errors++;
 607                dev_kfree_skb(skb);
 608                return NETDEV_TX_OK;
 609        }
 610        dma_unmap_addr_set(&priv->tx_buff[*txbd_curr], addr, addr);
 611        dma_unmap_len_set(&priv->tx_buff[*txbd_curr], len, len);
 612
 613        priv->tx_buff[*txbd_curr].skb = skb;
 614        priv->txbd[*txbd_curr].data = cpu_to_le32(addr);
 615
 616        /* Make sure pointer to data buffer is set */
 617        wmb();
 618
 619        skb_tx_timestamp(skb);
 620
 621        *info = cpu_to_le32(FOR_EMAC | FIRST_OR_LAST_MASK | len);
 622
 623        /* Increment index to point to the next BD */
 624        *txbd_curr = (*txbd_curr + 1) % TX_BD_NUM;
 625
 626        /* Ensure that tx_clean() sees the new txbd_curr before
 627         * checking the queue status. This prevents an unneeded wake
 628         * of the queue in tx_clean().
 629         */
 630        smp_mb();
 631
 632        if (!arc_emac_tx_avail(priv)) {
 633                netif_stop_queue(ndev);
 634                /* Refresh tx_dirty */
 635                smp_mb();
 636                if (arc_emac_tx_avail(priv))
 637                        netif_start_queue(ndev);
 638        }
 639
 640        arc_reg_set(priv, R_STATUS, TXPL_MASK);
 641
 642        return NETDEV_TX_OK;
 643}
 644
 645static void arc_emac_set_address_internal(struct net_device *ndev)
 646{
 647        struct arc_emac_priv *priv = netdev_priv(ndev);
 648        unsigned int addr_low, addr_hi;
 649
 650        addr_low = le32_to_cpu(*(__le32 *) &ndev->dev_addr[0]);
 651        addr_hi = le16_to_cpu(*(__le16 *) &ndev->dev_addr[4]);
 652
 653        arc_reg_set(priv, R_ADDRL, addr_low);
 654        arc_reg_set(priv, R_ADDRH, addr_hi);
 655}
 656
 657/**
 658 * arc_emac_set_address - Set the MAC address for this device.
 659 * @ndev:       Pointer to net_device structure.
 660 * @p:          6 byte Address to be written as MAC address.
 661 *
 662 * This function copies the HW address from the sockaddr structure to the
 663 * net_device structure and updates the address in HW.
 664 *
 665 * returns:     -EBUSY if the net device is busy or 0 if the address is set
 666 *              successfully.
 667 */
 668static int arc_emac_set_address(struct net_device *ndev, void *p)
 669{
 670        struct sockaddr *addr = p;
 671
 672        if (netif_running(ndev))
 673                return -EBUSY;
 674
 675        if (!is_valid_ether_addr(addr->sa_data))
 676                return -EADDRNOTAVAIL;
 677
 678        memcpy(ndev->dev_addr, addr->sa_data, ndev->addr_len);
 679
 680        arc_emac_set_address_internal(ndev);
 681
 682        return 0;
 683}
 684
 685static const struct net_device_ops arc_emac_netdev_ops = {
 686        .ndo_open               = arc_emac_open,
 687        .ndo_stop               = arc_emac_stop,
 688        .ndo_start_xmit         = arc_emac_tx,
 689        .ndo_set_mac_address    = arc_emac_set_address,
 690        .ndo_get_stats          = arc_emac_stats,
 691        .ndo_set_rx_mode        = arc_emac_set_rx_mode,
 692#ifdef CONFIG_NET_POLL_CONTROLLER
 693        .ndo_poll_controller    = arc_emac_poll_controller,
 694#endif
 695};
 696
 697int arc_emac_probe(struct net_device *ndev, int interface)
 698{
 699        struct device *dev = ndev->dev.parent;
 700        struct resource res_regs;
 701        struct device_node *phy_node;
 702        struct arc_emac_priv *priv;
 703        const char *mac_addr;
 704        unsigned int id, clock_frequency, irq;
 705        int err;
 706
 707
 708        /* Get PHY from device tree */
 709        phy_node = of_parse_phandle(dev->of_node, "phy", 0);
 710        if (!phy_node) {
 711                dev_err(dev, "failed to retrieve phy description from device tree\n");
 712                return -ENODEV;
 713        }
 714
 715        /* Get EMAC registers base address from device tree */
 716        err = of_address_to_resource(dev->of_node, 0, &res_regs);
 717        if (err) {
 718                dev_err(dev, "failed to retrieve registers base from device tree\n");
 719                return -ENODEV;
 720        }
 721
 722        /* Get IRQ from device tree */
 723        irq = irq_of_parse_and_map(dev->of_node, 0);
 724        if (!irq) {
 725                dev_err(dev, "failed to retrieve <irq> value from device tree\n");
 726                return -ENODEV;
 727        }
 728
 729
 730        ndev->netdev_ops = &arc_emac_netdev_ops;
 731        ndev->ethtool_ops = &arc_emac_ethtool_ops;
 732        ndev->watchdog_timeo = TX_TIMEOUT;
 733        /* FIXME :: no multicast support yet */
 734        ndev->flags &= ~IFF_MULTICAST;
 735
 736        priv = netdev_priv(ndev);
 737        priv->dev = dev;
 738
 739        priv->regs = devm_ioremap_resource(dev, &res_regs);
 740        if (IS_ERR(priv->regs)) {
 741                return PTR_ERR(priv->regs);
 742        }
 743        dev_dbg(dev, "Registers base address is 0x%p\n", priv->regs);
 744
 745        if (priv->clk) {
 746                err = clk_prepare_enable(priv->clk);
 747                if (err) {
 748                        dev_err(dev, "failed to enable clock\n");
 749                        return err;
 750                }
 751
 752                clock_frequency = clk_get_rate(priv->clk);
 753        } else {
 754                /* Get CPU clock frequency from device tree */
 755                if (of_property_read_u32(dev->of_node, "clock-frequency",
 756                                         &clock_frequency)) {
 757                        dev_err(dev, "failed to retrieve <clock-frequency> from device tree\n");
 758                        return -EINVAL;
 759                }
 760        }
 761
 762        id = arc_reg_get(priv, R_ID);
 763
 764        /* Check for EMAC revision 5 or 7, magic number */
 765        if (!(id == 0x0005fd02 || id == 0x0007fd02)) {
 766                dev_err(dev, "ARC EMAC not detected, id=0x%x\n", id);
 767                err = -ENODEV;
 768                goto out_clken;
 769        }
 770        dev_info(dev, "ARC EMAC detected with id: 0x%x\n", id);
 771
 772        /* Set poll rate so that it polls every 1 ms */
 773        arc_reg_set(priv, R_POLLRATE, clock_frequency / 1000000);
 774
 775        ndev->irq = irq;
 776        dev_info(dev, "IRQ is %d\n", ndev->irq);
 777
 778        /* Register interrupt handler for device */
 779        err = devm_request_irq(dev, ndev->irq, arc_emac_intr, 0,
 780                               ndev->name, ndev);
 781        if (err) {
 782                dev_err(dev, "could not allocate IRQ\n");
 783                goto out_clken;
 784        }
 785
 786        /* Get MAC address from device tree */
 787        mac_addr = of_get_mac_address(dev->of_node);
 788
 789        if (mac_addr)
 790                memcpy(ndev->dev_addr, mac_addr, ETH_ALEN);
 791        else
 792                eth_hw_addr_random(ndev);
 793
 794        arc_emac_set_address_internal(ndev);
 795        dev_info(dev, "MAC address is now %pM\n", ndev->dev_addr);
 796
 797        /* Do 1 allocation instead of 2 separate ones for Rx and Tx BD rings */
 798        priv->rxbd = dmam_alloc_coherent(dev, RX_RING_SZ + TX_RING_SZ,
 799                                         &priv->rxbd_dma, GFP_KERNEL);
 800
 801        if (!priv->rxbd) {
 802                dev_err(dev, "failed to allocate data buffers\n");
 803                err = -ENOMEM;
 804                goto out_clken;
 805        }
 806
 807        priv->txbd = priv->rxbd + RX_BD_NUM;
 808
 809        priv->txbd_dma = priv->rxbd_dma + RX_RING_SZ;
 810        dev_dbg(dev, "EMAC Device addr: Rx Ring [0x%x], Tx Ring[%x]\n",
 811                (unsigned int)priv->rxbd_dma, (unsigned int)priv->txbd_dma);
 812
 813        err = arc_mdio_probe(priv);
 814        if (err) {
 815                dev_err(dev, "failed to probe MII bus\n");
 816                goto out_clken;
 817        }
 818
 819        priv->phy_dev = of_phy_connect(ndev, phy_node, arc_emac_adjust_link, 0,
 820                                       interface);
 821        if (!priv->phy_dev) {
 822                dev_err(dev, "of_phy_connect() failed\n");
 823                err = -ENODEV;
 824                goto out_mdio;
 825        }
 826
 827        dev_info(dev, "connected to %s phy with id 0x%x\n",
 828                 priv->phy_dev->drv->name, priv->phy_dev->phy_id);
 829
 830        netif_napi_add(ndev, &priv->napi, arc_emac_poll, ARC_EMAC_NAPI_WEIGHT);
 831
 832        err = register_netdev(ndev);
 833        if (err) {
 834                dev_err(dev, "failed to register network device\n");
 835                goto out_netif_api;
 836        }
 837
 838        return 0;
 839
 840out_netif_api:
 841        netif_napi_del(&priv->napi);
 842        phy_disconnect(priv->phy_dev);
 843        priv->phy_dev = NULL;
 844out_mdio:
 845        arc_mdio_remove(priv);
 846out_clken:
 847        if (priv->clk)
 848                clk_disable_unprepare(priv->clk);
 849        return err;
 850}
 851EXPORT_SYMBOL_GPL(arc_emac_probe);
 852
 853int arc_emac_remove(struct net_device *ndev)
 854{
 855        struct arc_emac_priv *priv = netdev_priv(ndev);
 856
 857        phy_disconnect(priv->phy_dev);
 858        priv->phy_dev = NULL;
 859        arc_mdio_remove(priv);
 860        unregister_netdev(ndev);
 861        netif_napi_del(&priv->napi);
 862
 863        if (!IS_ERR(priv->clk)) {
 864                clk_disable_unprepare(priv->clk);
 865        }
 866
 867
 868        return 0;
 869}
 870EXPORT_SYMBOL_GPL(arc_emac_remove);
 871
 872MODULE_AUTHOR("Alexey Brodkin <abrodkin@synopsys.com>");
 873MODULE_DESCRIPTION("ARC EMAC driver");
 874MODULE_LICENSE("GPL");
 875
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