drivers/net/ethernet/lantiq_xrx200.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Lantiq / Intel PMAC driver for XRX200 SoCs
   4  *
   5  * Copyright (C) 2010 Lantiq Deutschland
   6  * Copyright (C) 2012 John Crispin <john@phrozen.org>
   7  * Copyright (C) 2017 - 2018 Hauke Mehrtens <hauke@hauke-m.de>
   8  */
   9
  10 #include <linux/etherdevice.h>
  11 #include <linux/module.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/clk.h>
  15 #include <linux/delay.h>
  16
  17 #include <linux/if_vlan.h>
  18
  19 #include <linux/of_net.h>
  20 #include <linux/of_platform.h>
  21
  22 #include <xway_dma.h>
  23
  24 /* DMA */
  25 #define XRX200_DMA_DATA_LEN     (SZ_64K - 1)
  26 #define XRX200_DMA_RX           0
  27 #define XRX200_DMA_TX           1
  28 #define XRX200_DMA_BURST_LEN    8
  29
  30 #define XRX200_DMA_PACKET_COMPLETE      0
  31 #define XRX200_DMA_PACKET_IN_PROGRESS   1
  32
  33 /* cpu port mac */
  34 #define PMAC_RX_IPG             0x0024
  35 #define PMAC_RX_IPG_MASK        0xf
  36
  37 #define PMAC_HD_CTL             0x0000
  38 /* Add Ethernet header to packets from DMA to PMAC */
  39 #define PMAC_HD_CTL_ADD         BIT(0)
  40 /* Add VLAN tag to Packets from DMA to PMAC */
  41 #define PMAC_HD_CTL_TAG         BIT(1)
  42 /* Add CRC to packets from DMA to PMAC */
  43 #define PMAC_HD_CTL_AC          BIT(2)
  44 /* Add status header to packets from PMAC to DMA */
  45 #define PMAC_HD_CTL_AS          BIT(3)
  46 /* Remove CRC from packets from PMAC to DMA */
  47 #define PMAC_HD_CTL_RC          BIT(4)
  48 /* Remove Layer-2 header from packets from PMAC to DMA */
  49 #define PMAC_HD_CTL_RL2         BIT(5)
  50 /* Status header is present from DMA to PMAC */
  51 #define PMAC_HD_CTL_RXSH        BIT(6)
  52 /* Add special tag from PMAC to switch */
  53 #define PMAC_HD_CTL_AST         BIT(7)
  54 /* Remove specail Tag from PMAC to DMA */
  55 #define PMAC_HD_CTL_RST         BIT(8)
  56 /* Check CRC from DMA to PMAC */
  57 #define PMAC_HD_CTL_CCRC        BIT(9)
  58 /* Enable reaction to Pause frames in the PMAC */
  59 #define PMAC_HD_CTL_FC          BIT(10)
  60
  61 struct xrx200_chan {
  62         int tx_free;
  63
  64         struct napi_struct napi;
  65         struct ltq_dma_channel dma;
  66
  67         union {
  68                 struct sk_buff *skb[LTQ_DESC_NUM];
  69                 void *rx_buff[LTQ_DESC_NUM];
  70         };
  71
  72         struct sk_buff *skb_head;
  73         struct sk_buff *skb_tail;
  74
  75         struct xrx200_priv *priv;
  76 };
  77
  78 struct xrx200_priv {
  79         struct clk *clk;
  80
  81         struct xrx200_chan chan_tx;
  82         struct xrx200_chan chan_rx;
  83
  84         u16 rx_buf_size;
  85         u16 rx_skb_size;
  86
  87         struct net_device *net_dev;
  88         struct device *dev;
  89
  90         __iomem void *pmac_reg;
  91 };
  92
  93 static u32 xrx200_pmac_r32(struct xrx200_priv *priv, u32 offset)
  94 {
  95         return __raw_readl(priv->pmac_reg + offset);
  96 }
  97
  98 static void xrx200_pmac_w32(struct xrx200_priv *priv, u32 val, u32 offset)
  99 {
 100         __raw_writel(val, priv->pmac_reg + offset);
 101 }
 102
 103 static void xrx200_pmac_mask(struct xrx200_priv *priv, u32 clear, u32 set,
 104                              u32 offset)
 105 {
 106         u32 val = xrx200_pmac_r32(priv, offset);
 107
 108         val &= ~(clear);
 109         val |= set;
 110         xrx200_pmac_w32(priv, val, offset);
 111 }
 112
 113 static int xrx200_max_frame_len(int mtu)
 114 {
 115         return VLAN_ETH_HLEN + mtu;
 116 }
 117
 118 static int xrx200_buffer_size(int mtu)
 119 {
 120         return round_up(xrx200_max_frame_len(mtu), 4 * XRX200_DMA_BURST_LEN);
 121 }
 122
 123 static int xrx200_skb_size(u16 buf_size)
 124 {
 125         return SKB_DATA_ALIGN(buf_size + NET_SKB_PAD + NET_IP_ALIGN) +
 126                 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 127 }
 128
 129 /* drop all the packets from the DMA ring */
 130 static void xrx200_flush_dma(struct xrx200_chan *ch)
 131 {
 132         int i;
 133
 134         for (i = 0; i < LTQ_DESC_NUM; i++) {
 135                 struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
 136
 137                 if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) != LTQ_DMA_C)
 138                         break;
 139
 140                 desc->ctl = LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) |
 141                             ch->priv->rx_buf_size;
 142                 ch->dma.desc++;
 143                 ch->dma.desc %= LTQ_DESC_NUM;
 144         }
 145 }
 146
 147 static int xrx200_open(struct net_device *net_dev)
 148 {
 149         struct xrx200_priv *priv = netdev_priv(net_dev);
 150
 151         napi_enable(&priv->chan_tx.napi);
 152         ltq_dma_open(&priv->chan_tx.dma);
 153         ltq_dma_enable_irq(&priv->chan_tx.dma);
 154
 155         napi_enable(&priv->chan_rx.napi);
 156         ltq_dma_open(&priv->chan_rx.dma);
 157         /* The boot loader does not always deactivate the receiving of frames
 158          * on the ports and then some packets queue up in the PPE buffers.
 159          * They already passed the PMAC so they do not have the tags
 160          * configured here. Read the these packets here and drop them.
 161          * The HW should have written them into memory after 10us
 162          */
 163         usleep_range(20, 40);
 164         xrx200_flush_dma(&priv->chan_rx);
 165         ltq_dma_enable_irq(&priv->chan_rx.dma);
 166
 167         netif_wake_queue(net_dev);
 168
 169         return 0;
 170 }
 171
 172 static int xrx200_close(struct net_device *net_dev)
 173 {
 174         struct xrx200_priv *priv = netdev_priv(net_dev);
 175
 176         netif_stop_queue(net_dev);
 177
 178         napi_disable(&priv->chan_rx.napi);
 179         ltq_dma_close(&priv->chan_rx.dma);
 180
 181         napi_disable(&priv->chan_tx.napi);
 182         ltq_dma_close(&priv->chan_tx.dma);
 183
 184         return 0;
 185 }
 186
 187 static int xrx200_alloc_buf(struct xrx200_chan *ch, void *(*alloc)(unsigned int size))
 188 {
 189         void *buf = ch->rx_buff[ch->dma.desc];
 190         struct xrx200_priv *priv = ch->priv;
 191         dma_addr_t mapping;
 192         int ret = 0;
 193
 194         ch->rx_buff[ch->dma.desc] = alloc(priv->rx_skb_size);
 195         if (!ch->rx_buff[ch->dma.desc]) {
 196                 ch->rx_buff[ch->dma.desc] = buf;
 197                 ret = -ENOMEM;
 198                 goto skip;
 199         }
 200
 201         mapping = dma_map_single(priv->dev, ch->rx_buff[ch->dma.desc],
 202                                  priv->rx_buf_size, DMA_FROM_DEVICE);
 203         if (unlikely(dma_mapping_error(priv->dev, mapping))) {
 204                 skb_free_frag(ch->rx_buff[ch->dma.desc]);
 205                 ch->rx_buff[ch->dma.desc] = buf;
 206                 ret = -ENOMEM;
 207                 goto skip;
 208         }
 209
 210         ch->dma.desc_base[ch->dma.desc].addr = mapping + NET_SKB_PAD + NET_IP_ALIGN;
 211         /* Make sure the address is written before we give it to HW */
 212         wmb();
 213 skip:
 214         ch->dma.desc_base[ch->dma.desc].ctl =
 215                 LTQ_DMA_OWN | LTQ_DMA_RX_OFFSET(NET_IP_ALIGN) | priv->rx_buf_size;
 216
 217         return ret;
 218 }
 219
 220 static int xrx200_hw_receive(struct xrx200_chan *ch)
 221 {
 222         struct xrx200_priv *priv = ch->priv;
 223         struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
 224         void *buf = ch->rx_buff[ch->dma.desc];
 225         u32 ctl = desc->ctl;
 226         int len = (ctl & LTQ_DMA_SIZE_MASK);
 227         struct net_device *net_dev = priv->net_dev;
 228         struct sk_buff *skb;
 229         int ret;
 230
 231         ret = xrx200_alloc_buf(ch, napi_alloc_frag);
 232
 233         ch->dma.desc++;
 234         ch->dma.desc %= LTQ_DESC_NUM;
 235
 236         if (ret) {
 237                 net_dev->stats.rx_dropped++;
 238                 netdev_err(net_dev, "failed to allocate new rx buffer\n");
 239                 return ret;
 240         }
 241
 242         skb = build_skb(buf, priv->rx_skb_size);
 243         if (!skb) {
 244                 skb_free_frag(buf);
 245                 net_dev->stats.rx_dropped++;
 246                 return -ENOMEM;
 247         }
 248
 249         skb_reserve(skb, NET_SKB_PAD);
 250         skb_put(skb, len);
 251
 252         /* add buffers to skb via skb->frag_list */
 253         if (ctl & LTQ_DMA_SOP) {
 254                 ch->skb_head = skb;
 255                 ch->skb_tail = skb;
 256                 skb_reserve(skb, NET_IP_ALIGN);
 257         } else if (ch->skb_head) {
 258                 if (ch->skb_head == ch->skb_tail)
 259                         skb_shinfo(ch->skb_tail)->frag_list = skb;
 260                 else
 261                         ch->skb_tail->next = skb;
 262                 ch->skb_tail = skb;
 263                 ch->skb_head->len += skb->len;
 264                 ch->skb_head->data_len += skb->len;
 265                 ch->skb_head->truesize += skb->truesize;
 266         }
 267
 268         if (ctl & LTQ_DMA_EOP) {
 269                 ch->skb_head->protocol = eth_type_trans(ch->skb_head, net_dev);
 270                 net_dev->stats.rx_packets++;
 271                 net_dev->stats.rx_bytes += ch->skb_head->len;
 272                 netif_receive_skb(ch->skb_head);
 273                 ch->skb_head = NULL;
 274                 ch->skb_tail = NULL;
 275                 ret = XRX200_DMA_PACKET_COMPLETE;
 276         } else {
 277                 ret = XRX200_DMA_PACKET_IN_PROGRESS;
 278         }
 279
 280         return ret;
 281 }
 282
 283 static int xrx200_poll_rx(struct napi_struct *napi, int budget)
 284 {
 285         struct xrx200_chan *ch = container_of(napi,
 286                                 struct xrx200_chan, napi);
 287         int rx = 0;
 288         int ret;
 289
 290         while (rx < budget) {
 291                 struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
 292
 293                 if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
 294                         ret = xrx200_hw_receive(ch);
 295                         if (ret == XRX200_DMA_PACKET_IN_PROGRESS)
 296                                 continue;
 297                         if (ret != XRX200_DMA_PACKET_COMPLETE)
 298                                 break;
 299                         rx++;
 300                 } else {
 301                         break;
 302                 }
 303         }
 304
 305         if (rx < budget) {
 306                 if (napi_complete_done(&ch->napi, rx))
 307                         ltq_dma_enable_irq(&ch->dma);
 308         }
 309
 310         return rx;
 311 }
 312
 313 static int xrx200_tx_housekeeping(struct napi_struct *napi, int budget)
 314 {
 315         struct xrx200_chan *ch = container_of(napi,
 316                                 struct xrx200_chan, napi);
 317         struct net_device *net_dev = ch->priv->net_dev;
 318         int pkts = 0;
 319         int bytes = 0;
 320
 321         netif_tx_lock(net_dev);
 322         while (pkts < budget) {
 323                 struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->tx_free];
 324
 325                 if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) == LTQ_DMA_C) {
 326                         struct sk_buff *skb = ch->skb[ch->tx_free];
 327
 328                         pkts++;
 329                         bytes += skb->len;
 330                         ch->skb[ch->tx_free] = NULL;
 331                         consume_skb(skb);
 332                         memset(&ch->dma.desc_base[ch->tx_free], 0,
 333                                sizeof(struct ltq_dma_desc));
 334                         ch->tx_free++;
 335                         ch->tx_free %= LTQ_DESC_NUM;
 336                 } else {
 337                         break;
 338                 }
 339         }
 340
 341         net_dev->stats.tx_packets += pkts;
 342         net_dev->stats.tx_bytes += bytes;
 343         netdev_completed_queue(ch->priv->net_dev, pkts, bytes);
 344
 345         netif_tx_unlock(net_dev);
 346         if (netif_queue_stopped(net_dev))
 347                 netif_wake_queue(net_dev);
 348
 349         if (pkts < budget) {
 350                 if (napi_complete_done(&ch->napi, pkts))
 351                         ltq_dma_enable_irq(&ch->dma);
 352         }
 353
 354         return pkts;
 355 }
 356
 357 static netdev_tx_t xrx200_start_xmit(struct sk_buff *skb,
 358                                      struct net_device *net_dev)
 359 {
 360         struct xrx200_priv *priv = netdev_priv(net_dev);
 361         struct xrx200_chan *ch = &priv->chan_tx;
 362         struct ltq_dma_desc *desc = &ch->dma.desc_base[ch->dma.desc];
 363         u32 byte_offset;
 364         dma_addr_t mapping;
 365         int len;
 366
 367         skb->dev = net_dev;
 368         if (skb_put_padto(skb, ETH_ZLEN)) {
 369                 net_dev->stats.tx_dropped++;
 370                 return NETDEV_TX_OK;
 371         }
 372
 373         len = skb->len;
 374
 375         if ((desc->ctl & (LTQ_DMA_OWN | LTQ_DMA_C)) || ch->skb[ch->dma.desc]) {
 376                 netdev_err(net_dev, "tx ring full\n");
 377                 netif_stop_queue(net_dev);
 378                 return NETDEV_TX_BUSY;
 379         }
 380
 381         ch->skb[ch->dma.desc] = skb;
 382
 383         mapping = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);
 384         if (unlikely(dma_mapping_error(priv->dev, mapping)))
 385                 goto err_drop;
 386
 387         /* dma needs to start on a burst length value aligned address */
 388         byte_offset = mapping % (XRX200_DMA_BURST_LEN * 4);
 389
 390         desc->addr = mapping - byte_offset;
 391         /* Make sure the address is written before we give it to HW */
 392         wmb();
 393         desc->ctl = LTQ_DMA_OWN | LTQ_DMA_SOP | LTQ_DMA_EOP |
 394                 LTQ_DMA_TX_OFFSET(byte_offset) | (len & LTQ_DMA_SIZE_MASK);
 395         ch->dma.desc++;
 396         ch->dma.desc %= LTQ_DESC_NUM;
 397         if (ch->dma.desc == ch->tx_free)
 398                 netif_stop_queue(net_dev);
 399
 400         netdev_sent_queue(net_dev, len);
 401
 402         return NETDEV_TX_OK;
 403
 404 err_drop:
 405         dev_kfree_skb(skb);
 406         net_dev->stats.tx_dropped++;
 407         net_dev->stats.tx_errors++;
 408         return NETDEV_TX_OK;
 409 }
 410
 411 static int
 412 xrx200_change_mtu(struct net_device *net_dev, int new_mtu)
 413 {
 414         struct xrx200_priv *priv = netdev_priv(net_dev);
 415         struct xrx200_chan *ch_rx = &priv->chan_rx;
 416         int old_mtu = net_dev->mtu;
 417         bool running = false;
 418         void *buff;
 419         int curr_desc;
 420         int ret = 0;
 421
 422         WRITE_ONCE(net_dev->mtu, new_mtu);
 423         priv->rx_buf_size = xrx200_buffer_size(new_mtu);
 424         priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
 425
 426         if (new_mtu <= old_mtu)
 427                 return ret;
 428
 429         running = netif_running(net_dev);
 430         if (running) {
 431                 napi_disable(&ch_rx->napi);
 432                 ltq_dma_close(&ch_rx->dma);
 433         }
 434
 435         xrx200_poll_rx(&ch_rx->napi, LTQ_DESC_NUM);
 436         curr_desc = ch_rx->dma.desc;
 437
 438         for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
 439              ch_rx->dma.desc++) {
 440                 buff = ch_rx->rx_buff[ch_rx->dma.desc];
 441                 ret = xrx200_alloc_buf(ch_rx, netdev_alloc_frag);
 442                 if (ret) {
 443                         WRITE_ONCE(net_dev->mtu, old_mtu);
 444                         priv->rx_buf_size = xrx200_buffer_size(old_mtu);
 445                         priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
 446                         break;
 447                 }
 448                 skb_free_frag(buff);
 449         }
 450
 451         ch_rx->dma.desc = curr_desc;
 452         if (running) {
 453                 napi_enable(&ch_rx->napi);
 454                 ltq_dma_open(&ch_rx->dma);
 455                 ltq_dma_enable_irq(&ch_rx->dma);
 456         }
 457
 458         return ret;
 459 }
 460
 461 static const struct net_device_ops xrx200_netdev_ops = {
 462         .ndo_open               = xrx200_open,
 463         .ndo_stop               = xrx200_close,
 464         .ndo_start_xmit         = xrx200_start_xmit,
 465         .ndo_change_mtu         = xrx200_change_mtu,
 466         .ndo_set_mac_address    = eth_mac_addr,
 467         .ndo_validate_addr      = eth_validate_addr,
 468 };
 469
 470 static irqreturn_t xrx200_dma_irq(int irq, void *ptr)
 471 {
 472         struct xrx200_chan *ch = ptr;
 473
 474         if (napi_schedule_prep(&ch->napi)) {
 475                 ltq_dma_disable_irq(&ch->dma);
 476                 __napi_schedule(&ch->napi);
 477         }
 478
 479         ltq_dma_ack_irq(&ch->dma);
 480
 481         return IRQ_HANDLED;
 482 }
 483
 484 static int xrx200_dma_init(struct xrx200_priv *priv)
 485 {
 486         struct xrx200_chan *ch_rx = &priv->chan_rx;
 487         struct xrx200_chan *ch_tx = &priv->chan_tx;
 488         int ret = 0;
 489         int i;
 490
 491         ltq_dma_init_port(DMA_PORT_ETOP, XRX200_DMA_BURST_LEN,
 492                           XRX200_DMA_BURST_LEN);
 493
 494         ch_rx->dma.nr = XRX200_DMA_RX;
 495         ch_rx->dma.dev = priv->dev;
 496         ch_rx->priv = priv;
 497
 498         ltq_dma_alloc_rx(&ch_rx->dma);
 499         for (ch_rx->dma.desc = 0; ch_rx->dma.desc < LTQ_DESC_NUM;
 500              ch_rx->dma.desc++) {
 501                 ret = xrx200_alloc_buf(ch_rx, netdev_alloc_frag);
 502                 if (ret)
 503                         goto rx_free;
 504         }
 505         ch_rx->dma.desc = 0;
 506         ret = devm_request_irq(priv->dev, ch_rx->dma.irq, xrx200_dma_irq, 0,
 507                                "xrx200_net_rx", &priv->chan_rx);
 508         if (ret) {
 509                 dev_err(priv->dev, "failed to request RX irq %d\n",
 510                         ch_rx->dma.irq);
 511                 goto rx_ring_free;
 512         }
 513
 514         ch_tx->dma.nr = XRX200_DMA_TX;
 515         ch_tx->dma.dev = priv->dev;
 516         ch_tx->priv = priv;
 517
 518         ltq_dma_alloc_tx(&ch_tx->dma);
 519         ret = devm_request_irq(priv->dev, ch_tx->dma.irq, xrx200_dma_irq, 0,
 520                                "xrx200_net_tx", &priv->chan_tx);
 521         if (ret) {
 522                 dev_err(priv->dev, "failed to request TX irq %d\n",
 523                         ch_tx->dma.irq);
 524                 goto tx_free;
 525         }
 526
 527         return ret;
 528
 529 tx_free:
 530         ltq_dma_free(&ch_tx->dma);
 531
 532 rx_ring_free:
 533         /* free the allocated RX ring */
 534         for (i = 0; i < LTQ_DESC_NUM; i++) {
 535                 if (priv->chan_rx.skb[i])
 536                         skb_free_frag(priv->chan_rx.rx_buff[i]);
 537         }
 538
 539 rx_free:
 540         ltq_dma_free(&ch_rx->dma);
 541         return ret;
 542 }
 543
 544 static void xrx200_hw_cleanup(struct xrx200_priv *priv)
 545 {
 546         int i;
 547
 548         ltq_dma_free(&priv->chan_tx.dma);
 549         ltq_dma_free(&priv->chan_rx.dma);
 550
 551         /* free the allocated RX ring */
 552         for (i = 0; i < LTQ_DESC_NUM; i++)
 553                 skb_free_frag(priv->chan_rx.rx_buff[i]);
 554 }
 555
 556 static int xrx200_probe(struct platform_device *pdev)
 557 {
 558         struct device *dev = &pdev->dev;
 559         struct device_node *np = dev->of_node;
 560         struct xrx200_priv *priv;
 561         struct net_device *net_dev;
 562         int err;
 563
 564         /* alloc the network device */
 565         net_dev = devm_alloc_etherdev(dev, sizeof(struct xrx200_priv));
 566         if (!net_dev)
 567                 return -ENOMEM;
 568
 569         priv = netdev_priv(net_dev);
 570         priv->net_dev = net_dev;
 571         priv->dev = dev;
 572
 573         net_dev->netdev_ops = &xrx200_netdev_ops;
 574         SET_NETDEV_DEV(net_dev, dev);
 575         net_dev->min_mtu = ETH_ZLEN;
 576         net_dev->max_mtu = XRX200_DMA_DATA_LEN - xrx200_max_frame_len(0);
 577         priv->rx_buf_size = xrx200_buffer_size(ETH_DATA_LEN);
 578         priv->rx_skb_size = xrx200_skb_size(priv->rx_buf_size);
 579
 580         /* load the memory ranges */
 581         priv->pmac_reg = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
 582         if (IS_ERR(priv->pmac_reg))
 583                 return PTR_ERR(priv->pmac_reg);
 584
 585         priv->chan_rx.dma.irq = platform_get_irq_byname(pdev, "rx");
 586         if (priv->chan_rx.dma.irq < 0)
 587                 return -ENOENT;
 588         priv->chan_tx.dma.irq = platform_get_irq_byname(pdev, "tx");
 589         if (priv->chan_tx.dma.irq < 0)
 590                 return -ENOENT;
 591
 592         /* get the clock */
 593         priv->clk = devm_clk_get(dev, NULL);
 594         if (IS_ERR(priv->clk)) {
 595                 dev_err(dev, "failed to get clock\n");
 596                 return PTR_ERR(priv->clk);
 597         }
 598
 599         err = of_get_ethdev_address(np, net_dev);
 600         if (err)
 601                 eth_hw_addr_random(net_dev);
 602
 603         /* bring up the dma engine and IP core */
 604         err = xrx200_dma_init(priv);
 605         if (err)
 606                 return err;
 607
 608         /* enable clock gate */
 609         err = clk_prepare_enable(priv->clk);
 610         if (err)
 611                 goto err_uninit_dma;
 612
 613         /* set IPG to 12 */
 614         xrx200_pmac_mask(priv, PMAC_RX_IPG_MASK, 0xb, PMAC_RX_IPG);
 615
 616         /* enable status header, enable CRC */
 617         xrx200_pmac_mask(priv, 0,
 618                          PMAC_HD_CTL_RST | PMAC_HD_CTL_AST | PMAC_HD_CTL_RXSH |
 619                          PMAC_HD_CTL_AS | PMAC_HD_CTL_AC | PMAC_HD_CTL_RC,
 620                          PMAC_HD_CTL);
 621
 622         /* setup NAPI */
 623         netif_napi_add(net_dev, &priv->chan_rx.napi, xrx200_poll_rx);
 624         netif_napi_add_tx(net_dev, &priv->chan_tx.napi,
 625                           xrx200_tx_housekeeping);
 626
 627         platform_set_drvdata(pdev, priv);
 628
 629         err = register_netdev(net_dev);
 630         if (err)
 631                 goto err_unprepare_clk;
 632
 633         return 0;
 634
 635 err_unprepare_clk:
 636         clk_disable_unprepare(priv->clk);
 637
 638 err_uninit_dma:
 639         xrx200_hw_cleanup(priv);
 640
 641         return err;
 642 }
 643
 644 static void xrx200_remove(struct platform_device *pdev)
 645 {
 646         struct xrx200_priv *priv = platform_get_drvdata(pdev);
 647         struct net_device *net_dev = priv->net_dev;
 648
 649         /* free stack related instances */
 650         netif_stop_queue(net_dev);
 651         netif_napi_del(&priv->chan_tx.napi);
 652         netif_napi_del(&priv->chan_rx.napi);
 653
 654         /* remove the actual device */
 655         unregister_netdev(net_dev);
 656
 657         /* release the clock */
 658         clk_disable_unprepare(priv->clk);
 659
 660         /* shut down hardware */
 661         xrx200_hw_cleanup(priv);
 662 }
 663
 664 static const struct of_device_id xrx200_match[] = {
 665         { .compatible = "lantiq,xrx200-net" },
 666         {},
 667 };
 668 MODULE_DEVICE_TABLE(of, xrx200_match);
 669
 670 static struct platform_driver xrx200_driver = {
 671         .probe = xrx200_probe,
 672         .remove = xrx200_remove,
 673         .driver = {
 674                 .name = "lantiq,xrx200-net",
 675                 .of_match_table = xrx200_match,
 676         },
 677 };
 678
 679 module_platform_driver(xrx200_driver);
 680
 681 MODULE_AUTHOR("John Crispin <john@phrozen.org>");
 682 MODULE_DESCRIPTION("Lantiq SoC XRX200 ethernet");
 683 MODULE_LICENSE("GPL");