drivers/net/ethernet/ec_bhf.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2  /*
   3  * drivers/net/ethernet/ec_bhf.c
   4  *
   5  * Copyright (C) 2014 Darek Marcinkiewicz <reksio@newterm.pl>
   6  */
   7
   8 /* This is a driver for EtherCAT master module present on CCAT FPGA.
   9  * Those can be found on Bechhoff CX50xx industrial PCs.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/moduleparam.h>
  15 #include <linux/pci.h>
  16 #include <linux/init.h>
  17
  18 #include <linux/netdevice.h>
  19 #include <linux/etherdevice.h>
  20 #include <linux/ip.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/hrtimer.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/stat.h>
  25
  26 #define TIMER_INTERVAL_NSEC     20000
  27
  28 #define INFO_BLOCK_SIZE         0x10
  29 #define INFO_BLOCK_TYPE         0x0
  30 #define INFO_BLOCK_REV          0x2
  31 #define INFO_BLOCK_BLK_CNT      0x4
  32 #define INFO_BLOCK_TX_CHAN      0x4
  33 #define INFO_BLOCK_RX_CHAN      0x5
  34 #define INFO_BLOCK_OFFSET       0x8
  35
  36 #define EC_MII_OFFSET           0x4
  37 #define EC_FIFO_OFFSET          0x8
  38 #define EC_MAC_OFFSET           0xc
  39
  40 #define MAC_FRAME_ERR_CNT       0x0
  41 #define MAC_RX_ERR_CNT          0x1
  42 #define MAC_CRC_ERR_CNT         0x2
  43 #define MAC_LNK_LST_ERR_CNT     0x3
  44 #define MAC_TX_FRAME_CNT        0x10
  45 #define MAC_RX_FRAME_CNT        0x14
  46 #define MAC_TX_FIFO_LVL         0x20
  47 #define MAC_DROPPED_FRMS        0x28
  48 #define MAC_CONNECTED_CCAT_FLAG 0x78
  49
  50 #define MII_MAC_ADDR            0x8
  51 #define MII_MAC_FILT_FLAG       0xe
  52 #define MII_LINK_STATUS         0xf
  53
  54 #define FIFO_TX_REG             0x0
  55 #define FIFO_TX_RESET           0x8
  56 #define FIFO_RX_REG             0x10
  57 #define FIFO_RX_ADDR_VALID      (1u << 31)
  58 #define FIFO_RX_RESET           0x18
  59
  60 #define DMA_CHAN_OFFSET         0x1000
  61 #define DMA_CHAN_SIZE           0x8
  62
  63 #define DMA_WINDOW_SIZE_MASK    0xfffffffc
  64
  65 #define ETHERCAT_MASTER_ID      0x14
  66
  67 static const struct pci_device_id ids[] = {
  68         { PCI_DEVICE(0x15ec, 0x5000), },
  69         { 0, }
  70 };
  71 MODULE_DEVICE_TABLE(pci, ids);
  72
  73 struct rx_header {
  74 #define RXHDR_NEXT_ADDR_MASK    0xffffffu
  75 #define RXHDR_NEXT_VALID        (1u << 31)
  76         __le32 next;
  77 #define RXHDR_NEXT_RECV_FLAG    0x1
  78         __le32 recv;
  79 #define RXHDR_LEN_MASK          0xfffu
  80         __le16 len;
  81         __le16 port;
  82         __le32 reserved;
  83         u8 timestamp[8];
  84 } __packed;
  85
  86 #define PKT_PAYLOAD_SIZE        0x7e8
  87 struct rx_desc {
  88         struct rx_header header;
  89         u8 data[PKT_PAYLOAD_SIZE];
  90 } __packed;
  91
  92 struct tx_header {
  93         __le16 len;
  94 #define TX_HDR_PORT_0           0x1
  95 #define TX_HDR_PORT_1           0x2
  96         u8 port;
  97         u8 ts_enable;
  98 #define TX_HDR_SENT             0x1
  99         __le32 sent;
 100         u8 timestamp[8];
 101 } __packed;
 102
 103 struct tx_desc {
 104         struct tx_header header;
 105         u8 data[PKT_PAYLOAD_SIZE];
 106 } __packed;
 107
 108 #define FIFO_SIZE               64
 109
 110 static long polling_frequency = TIMER_INTERVAL_NSEC;
 111
 112 struct bhf_dma {
 113         u8 *buf;
 114         size_t len;
 115         dma_addr_t buf_phys;
 116
 117         u8 *alloc;
 118         size_t alloc_len;
 119         dma_addr_t alloc_phys;
 120 };
 121
 122 struct ec_bhf_priv {
 123         struct net_device *net_dev;
 124         struct pci_dev *dev;
 125
 126         void __iomem *io;
 127         void __iomem *dma_io;
 128
 129         struct hrtimer hrtimer;
 130
 131         int tx_dma_chan;
 132         int rx_dma_chan;
 133         void __iomem *ec_io;
 134         void __iomem *fifo_io;
 135         void __iomem *mii_io;
 136         void __iomem *mac_io;
 137
 138         struct bhf_dma rx_buf;
 139         struct rx_desc *rx_descs;
 140         int rx_dnext;
 141         int rx_dcount;
 142
 143         struct bhf_dma tx_buf;
 144         struct tx_desc *tx_descs;
 145         int tx_dcount;
 146         int tx_dnext;
 147
 148         u64 stat_rx_bytes;
 149         u64 stat_tx_bytes;
 150 };
 151
 152 #define PRIV_TO_DEV(priv) (&(priv)->dev->dev)
 153
 154 static void ec_bhf_reset(struct ec_bhf_priv *priv)
 155 {
 156         iowrite8(0, priv->mac_io + MAC_FRAME_ERR_CNT);
 157         iowrite8(0, priv->mac_io + MAC_RX_ERR_CNT);
 158         iowrite8(0, priv->mac_io + MAC_CRC_ERR_CNT);
 159         iowrite8(0, priv->mac_io + MAC_LNK_LST_ERR_CNT);
 160         iowrite32(0, priv->mac_io + MAC_TX_FRAME_CNT);
 161         iowrite32(0, priv->mac_io + MAC_RX_FRAME_CNT);
 162         iowrite8(0, priv->mac_io + MAC_DROPPED_FRMS);
 163
 164         iowrite8(0, priv->fifo_io + FIFO_TX_RESET);
 165         iowrite8(0, priv->fifo_io + FIFO_RX_RESET);
 166
 167         iowrite8(0, priv->mac_io + MAC_TX_FIFO_LVL);
 168 }
 169
 170 static void ec_bhf_send_packet(struct ec_bhf_priv *priv, struct tx_desc *desc)
 171 {
 172         u32 len = le16_to_cpu(desc->header.len) + sizeof(desc->header);
 173         u32 addr = (u8 *)desc - priv->tx_buf.buf;
 174
 175         iowrite32((ALIGN(len, 8) << 24) | addr, priv->fifo_io + FIFO_TX_REG);
 176 }
 177
 178 static int ec_bhf_desc_sent(struct tx_desc *desc)
 179 {
 180         return le32_to_cpu(desc->header.sent) & TX_HDR_SENT;
 181 }
 182
 183 static void ec_bhf_process_tx(struct ec_bhf_priv *priv)
 184 {
 185         if (unlikely(netif_queue_stopped(priv->net_dev))) {
 186                 /* Make sure that we perceive changes to tx_dnext. */
 187                 smp_rmb();
 188
 189                 if (ec_bhf_desc_sent(&priv->tx_descs[priv->tx_dnext]))
 190                         netif_wake_queue(priv->net_dev);
 191         }
 192 }
 193
 194 static int ec_bhf_pkt_received(struct rx_desc *desc)
 195 {
 196         return le32_to_cpu(desc->header.recv) & RXHDR_NEXT_RECV_FLAG;
 197 }
 198
 199 static void ec_bhf_add_rx_desc(struct ec_bhf_priv *priv, struct rx_desc *desc)
 200 {
 201         iowrite32(FIFO_RX_ADDR_VALID | ((u8 *)(desc) - priv->rx_buf.buf),
 202                   priv->fifo_io + FIFO_RX_REG);
 203 }
 204
 205 static void ec_bhf_process_rx(struct ec_bhf_priv *priv)
 206 {
 207         struct rx_desc *desc = &priv->rx_descs[priv->rx_dnext];
 208
 209         while (ec_bhf_pkt_received(desc)) {
 210                 int pkt_size = (le16_to_cpu(desc->header.len) &
 211                                RXHDR_LEN_MASK) - sizeof(struct rx_header) - 4;
 212                 u8 *data = desc->data;
 213                 struct sk_buff *skb;
 214
 215                 skb = netdev_alloc_skb_ip_align(priv->net_dev, pkt_size);
 216                 if (skb) {
 217                         skb_put_data(skb, data, pkt_size);
 218                         skb->protocol = eth_type_trans(skb, priv->net_dev);
 219                         priv->stat_rx_bytes += pkt_size;
 220
 221                         netif_rx(skb);
 222                 } else {
 223                         dev_err_ratelimited(PRIV_TO_DEV(priv),
 224                                             "Couldn't allocate a skb_buff for a packet of size %u\n",
 225                                             pkt_size);
 226                 }
 227
 228                 desc->header.recv = 0;
 229
 230                 ec_bhf_add_rx_desc(priv, desc);
 231
 232                 priv->rx_dnext = (priv->rx_dnext + 1) % priv->rx_dcount;
 233                 desc = &priv->rx_descs[priv->rx_dnext];
 234         }
 235 }
 236
 237 static enum hrtimer_restart ec_bhf_timer_fun(struct hrtimer *timer)
 238 {
 239         struct ec_bhf_priv *priv = container_of(timer, struct ec_bhf_priv,
 240                                                 hrtimer);
 241         ec_bhf_process_rx(priv);
 242         ec_bhf_process_tx(priv);
 243
 244         if (!netif_running(priv->net_dev))
 245                 return HRTIMER_NORESTART;
 246
 247         hrtimer_forward_now(timer, polling_frequency);
 248         return HRTIMER_RESTART;
 249 }
 250
 251 static int ec_bhf_setup_offsets(struct ec_bhf_priv *priv)
 252 {
 253         struct device *dev = PRIV_TO_DEV(priv);
 254         unsigned block_count, i;
 255         void __iomem *ec_info;
 256
 257         block_count = ioread8(priv->io + INFO_BLOCK_BLK_CNT);
 258         for (i = 0; i < block_count; i++) {
 259                 u16 type = ioread16(priv->io + i * INFO_BLOCK_SIZE +
 260                                     INFO_BLOCK_TYPE);
 261                 if (type == ETHERCAT_MASTER_ID)
 262                         break;
 263         }
 264         if (i == block_count) {
 265                 dev_err(dev, "EtherCAT master with DMA block not found\n");
 266                 return -ENODEV;
 267         }
 268
 269         ec_info = priv->io + i * INFO_BLOCK_SIZE;
 270
 271         priv->tx_dma_chan = ioread8(ec_info + INFO_BLOCK_TX_CHAN);
 272         priv->rx_dma_chan = ioread8(ec_info + INFO_BLOCK_RX_CHAN);
 273
 274         priv->ec_io = priv->io + ioread32(ec_info + INFO_BLOCK_OFFSET);
 275         priv->mii_io = priv->ec_io + ioread32(priv->ec_io + EC_MII_OFFSET);
 276         priv->fifo_io = priv->ec_io + ioread32(priv->ec_io + EC_FIFO_OFFSET);
 277         priv->mac_io = priv->ec_io + ioread32(priv->ec_io + EC_MAC_OFFSET);
 278
 279         return 0;
 280 }
 281
 282 static netdev_tx_t ec_bhf_start_xmit(struct sk_buff *skb,
 283                                      struct net_device *net_dev)
 284 {
 285         struct ec_bhf_priv *priv = netdev_priv(net_dev);
 286         struct tx_desc *desc;
 287         unsigned len;
 288
 289         desc = &priv->tx_descs[priv->tx_dnext];
 290
 291         skb_copy_and_csum_dev(skb, desc->data);
 292         len = skb->len;
 293
 294         memset(&desc->header, 0, sizeof(desc->header));
 295         desc->header.len = cpu_to_le16(len);
 296         desc->header.port = TX_HDR_PORT_0;
 297
 298         ec_bhf_send_packet(priv, desc);
 299
 300         priv->tx_dnext = (priv->tx_dnext + 1) % priv->tx_dcount;
 301
 302         if (!ec_bhf_desc_sent(&priv->tx_descs[priv->tx_dnext])) {
 303                 /* Make sure that updates to tx_dnext are perceived
 304                  * by timer routine.
 305                  */
 306                 smp_wmb();
 307
 308                 netif_stop_queue(net_dev);
 309         }
 310
 311         priv->stat_tx_bytes += len;
 312
 313         dev_kfree_skb(skb);
 314
 315         return NETDEV_TX_OK;
 316 }
 317
 318 static int ec_bhf_alloc_dma_mem(struct ec_bhf_priv *priv,
 319                                 struct bhf_dma *buf,
 320                                 int channel,
 321                                 int size)
 322 {
 323         int offset = channel * DMA_CHAN_SIZE + DMA_CHAN_OFFSET;
 324         struct device *dev = PRIV_TO_DEV(priv);
 325         u32 mask;
 326
 327         iowrite32(0xffffffff, priv->dma_io + offset);
 328
 329         mask = ioread32(priv->dma_io + offset);
 330         mask &= DMA_WINDOW_SIZE_MASK;
 331
 332         /* We want to allocate a chunk of memory that is:
 333          * - aligned to the mask we just read
 334          * - is of size 2^mask bytes (at most)
 335          * In order to ensure that we will allocate buffer of
 336          * 2 * 2^mask bytes.
 337          */
 338         buf->len = min_t(int, ~mask + 1, size);
 339         buf->alloc_len = 2 * buf->len;
 340
 341         buf->alloc = dma_alloc_coherent(dev, buf->alloc_len, &buf->alloc_phys,
 342                                         GFP_KERNEL);
 343         if (buf->alloc == NULL) {
 344                 dev_err(dev, "Failed to allocate buffer\n");
 345                 return -ENOMEM;
 346         }
 347
 348         buf->buf_phys = (buf->alloc_phys + buf->len) & mask;
 349         buf->buf = buf->alloc + (buf->buf_phys - buf->alloc_phys);
 350
 351         iowrite32(0, priv->dma_io + offset + 4);
 352         iowrite32(buf->buf_phys, priv->dma_io + offset);
 353
 354         return 0;
 355 }
 356
 357 static void ec_bhf_setup_tx_descs(struct ec_bhf_priv *priv)
 358 {
 359         int i = 0;
 360
 361         priv->tx_dcount = priv->tx_buf.len / sizeof(struct tx_desc);
 362         priv->tx_descs = (struct tx_desc *)priv->tx_buf.buf;
 363         priv->tx_dnext = 0;
 364
 365         for (i = 0; i < priv->tx_dcount; i++)
 366                 priv->tx_descs[i].header.sent = cpu_to_le32(TX_HDR_SENT);
 367 }
 368
 369 static void ec_bhf_setup_rx_descs(struct ec_bhf_priv *priv)
 370 {
 371         int i;
 372
 373         priv->rx_dcount = priv->rx_buf.len / sizeof(struct rx_desc);
 374         priv->rx_descs = (struct rx_desc *)priv->rx_buf.buf;
 375         priv->rx_dnext = 0;
 376
 377         for (i = 0; i < priv->rx_dcount; i++) {
 378                 struct rx_desc *desc = &priv->rx_descs[i];
 379                 u32 next;
 380
 381                 if (i != priv->rx_dcount - 1)
 382                         next = (u8 *)(desc + 1) - priv->rx_buf.buf;
 383                 else
 384                         next = 0;
 385                 next |= RXHDR_NEXT_VALID;
 386                 desc->header.next = cpu_to_le32(next);
 387                 desc->header.recv = 0;
 388                 ec_bhf_add_rx_desc(priv, desc);
 389         }
 390 }
 391
 392 static int ec_bhf_open(struct net_device *net_dev)
 393 {
 394         struct ec_bhf_priv *priv = netdev_priv(net_dev);
 395         struct device *dev = PRIV_TO_DEV(priv);
 396         int err = 0;
 397
 398         ec_bhf_reset(priv);
 399
 400         err = ec_bhf_alloc_dma_mem(priv, &priv->rx_buf, priv->rx_dma_chan,
 401                                    FIFO_SIZE * sizeof(struct rx_desc));
 402         if (err) {
 403                 dev_err(dev, "Failed to allocate rx buffer\n");
 404                 goto out;
 405         }
 406         ec_bhf_setup_rx_descs(priv);
 407
 408         err = ec_bhf_alloc_dma_mem(priv, &priv->tx_buf, priv->tx_dma_chan,
 409                                    FIFO_SIZE * sizeof(struct tx_desc));
 410         if (err) {
 411                 dev_err(dev, "Failed to allocate tx buffer\n");
 412                 goto error_rx_free;
 413         }
 414         iowrite8(0, priv->mii_io + MII_MAC_FILT_FLAG);
 415         ec_bhf_setup_tx_descs(priv);
 416
 417         netif_start_queue(net_dev);
 418
 419         hrtimer_init(&priv->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 420         priv->hrtimer.function = ec_bhf_timer_fun;
 421         hrtimer_start(&priv->hrtimer, polling_frequency, HRTIMER_MODE_REL);
 422
 423         return 0;
 424
 425 error_rx_free:
 426         dma_free_coherent(dev, priv->rx_buf.alloc_len, priv->rx_buf.alloc,
 427                           priv->rx_buf.alloc_len);
 428 out:
 429         return err;
 430 }
 431
 432 static int ec_bhf_stop(struct net_device *net_dev)
 433 {
 434         struct ec_bhf_priv *priv = netdev_priv(net_dev);
 435         struct device *dev = PRIV_TO_DEV(priv);
 436
 437         hrtimer_cancel(&priv->hrtimer);
 438
 439         ec_bhf_reset(priv);
 440
 441         netif_tx_disable(net_dev);
 442
 443         dma_free_coherent(dev, priv->tx_buf.alloc_len,
 444                           priv->tx_buf.alloc, priv->tx_buf.alloc_phys);
 445         dma_free_coherent(dev, priv->rx_buf.alloc_len,
 446                           priv->rx_buf.alloc, priv->rx_buf.alloc_phys);
 447
 448         return 0;
 449 }
 450
 451 static void
 452 ec_bhf_get_stats(struct net_device *net_dev,
 453                  struct rtnl_link_stats64 *stats)
 454 {
 455         struct ec_bhf_priv *priv = netdev_priv(net_dev);
 456
 457         stats->rx_errors = ioread8(priv->mac_io + MAC_RX_ERR_CNT) +
 458                                 ioread8(priv->mac_io + MAC_CRC_ERR_CNT) +
 459                                 ioread8(priv->mac_io + MAC_FRAME_ERR_CNT);
 460         stats->rx_packets = ioread32(priv->mac_io + MAC_RX_FRAME_CNT);
 461         stats->tx_packets = ioread32(priv->mac_io + MAC_TX_FRAME_CNT);
 462         stats->rx_dropped = ioread8(priv->mac_io + MAC_DROPPED_FRMS);
 463
 464         stats->tx_bytes = priv->stat_tx_bytes;
 465         stats->rx_bytes = priv->stat_rx_bytes;
 466 }
 467
 468 static const struct net_device_ops ec_bhf_netdev_ops = {
 469         .ndo_start_xmit         = ec_bhf_start_xmit,
 470         .ndo_open               = ec_bhf_open,
 471         .ndo_stop               = ec_bhf_stop,
 472         .ndo_get_stats64        = ec_bhf_get_stats,
 473         .ndo_validate_addr      = eth_validate_addr,
 474         .ndo_set_mac_address    = eth_mac_addr
 475 };
 476
 477 static int ec_bhf_probe(struct pci_dev *dev, const struct pci_device_id *id)
 478 {
 479         struct net_device *net_dev;
 480         struct ec_bhf_priv *priv;
 481         void __iomem *dma_io;
 482         void __iomem *io;
 483         int err = 0;
 484
 485         err = pci_enable_device(dev);
 486         if (err)
 487                 return err;
 488
 489         pci_set_master(dev);
 490
 491         err = pci_set_dma_mask(dev, DMA_BIT_MASK(32));
 492         if (err) {
 493                 dev_err(&dev->dev,
 494                         "Required dma mask not supported, failed to initialize device\n");
 495                 err = -EIO;
 496                 goto err_disable_dev;
 497         }
 498
 499         err = pci_set_consistent_dma_mask(dev, DMA_BIT_MASK(32));
 500         if (err) {
 501                 dev_err(&dev->dev,
 502                         "Required dma mask not supported, failed to initialize device\n");
 503                 goto err_disable_dev;
 504         }
 505
 506         err = pci_request_regions(dev, "ec_bhf");
 507         if (err) {
 508                 dev_err(&dev->dev, "Failed to request pci memory regions\n");
 509                 goto err_disable_dev;
 510         }
 511
 512         io = pci_iomap(dev, 0, 0);
 513         if (!io) {
 514                 dev_err(&dev->dev, "Failed to map pci card memory bar 0");
 515                 err = -EIO;
 516                 goto err_release_regions;
 517         }
 518
 519         dma_io = pci_iomap(dev, 2, 0);
 520         if (!dma_io) {
 521                 dev_err(&dev->dev, "Failed to map pci card memory bar 2");
 522                 err = -EIO;
 523                 goto err_unmap;
 524         }
 525
 526         net_dev = alloc_etherdev(sizeof(struct ec_bhf_priv));
 527         if (net_dev == NULL) {
 528                 err = -ENOMEM;
 529                 goto err_unmap_dma_io;
 530         }
 531
 532         pci_set_drvdata(dev, net_dev);
 533         SET_NETDEV_DEV(net_dev, &dev->dev);
 534
 535         net_dev->features = 0;
 536         net_dev->flags |= IFF_NOARP;
 537
 538         net_dev->netdev_ops = &ec_bhf_netdev_ops;
 539
 540         priv = netdev_priv(net_dev);
 541         priv->net_dev = net_dev;
 542         priv->io = io;
 543         priv->dma_io = dma_io;
 544         priv->dev = dev;
 545
 546         err = ec_bhf_setup_offsets(priv);
 547         if (err < 0)
 548                 goto err_free_net_dev;
 549
 550         memcpy_fromio(net_dev->dev_addr, priv->mii_io + MII_MAC_ADDR, 6);
 551
 552         err = register_netdev(net_dev);
 553         if (err < 0)
 554                 goto err_free_net_dev;
 555
 556         return 0;
 557
 558 err_free_net_dev:
 559         free_netdev(net_dev);
 560 err_unmap_dma_io:
 561         pci_iounmap(dev, dma_io);
 562 err_unmap:
 563         pci_iounmap(dev, io);
 564 err_release_regions:
 565         pci_release_regions(dev);
 566 err_disable_dev:
 567         pci_clear_master(dev);
 568         pci_disable_device(dev);
 569
 570         return err;
 571 }
 572
 573 static void ec_bhf_remove(struct pci_dev *dev)
 574 {
 575         struct net_device *net_dev = pci_get_drvdata(dev);
 576         struct ec_bhf_priv *priv = netdev_priv(net_dev);
 577
 578         unregister_netdev(net_dev);
 579         free_netdev(net_dev);
 580
 581         pci_iounmap(dev, priv->dma_io);
 582         pci_iounmap(dev, priv->io);
 583         pci_release_regions(dev);
 584         pci_clear_master(dev);
 585         pci_disable_device(dev);
 586 }
 587
 588 static struct pci_driver pci_driver = {
 589         .name           = "ec_bhf",
 590         .id_table       = ids,
 591         .probe          = ec_bhf_probe,
 592         .remove         = ec_bhf_remove,
 593 };
 594 module_pci_driver(pci_driver);
 595
 596 module_param(polling_frequency, long, 0444);
 597 MODULE_PARM_DESC(polling_frequency, "Polling timer frequency in ns");
 598
 599 MODULE_LICENSE("GPL");
 600 MODULE_AUTHOR("Dariusz Marcinkiewicz <reksio@newterm.pl>");