drivers/net/ethernet/ec_bhf.c

   1  /*
   2  * drivers/net/ethernet/ec_bhf.c
   3  *
   4  * Copyright (C) 2014 Darek Marcinkiewicz <reksio@newterm.pl>
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16
  17 /* This is a driver for EtherCAT master module present on CCAT FPGA.
  18  * Those can be found on Bechhoff CX50xx industrial PCs.
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/pci.h>
  25 #include <linux/init.h>
  26
  27 #include <linux/netdevice.h>
  28 #include <linux/etherdevice.h>
  29 #include <linux/ip.h>
  30 #include <linux/skbuff.h>
  31 #include <linux/hrtimer.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/stat.h>
  34
  35 #define TIMER_INTERVAL_NSEC     20000
  36
  37 #define INFO_BLOCK_SIZE         0x10
  38 #define INFO_BLOCK_TYPE         0x0
  39 #define INFO_BLOCK_REV          0x2
  40 #define INFO_BLOCK_BLK_CNT      0x4
  41 #define INFO_BLOCK_TX_CHAN      0x4
  42 #define INFO_BLOCK_RX_CHAN      0x5
  43 #define INFO_BLOCK_OFFSET       0x8
  44
  45 #define EC_MII_OFFSET           0x4
  46 #define EC_FIFO_OFFSET          0x8
  47 #define EC_MAC_OFFSET           0xc
  48
  49 #define MAC_FRAME_ERR_CNT       0x0
  50 #define MAC_RX_ERR_CNT          0x1
  51 #define MAC_CRC_ERR_CNT         0x2
  52 #define MAC_LNK_LST_ERR_CNT     0x3
  53 #define MAC_TX_FRAME_CNT        0x10
  54 #define MAC_RX_FRAME_CNT        0x14
  55 #define MAC_TX_FIFO_LVL         0x20
  56 #define MAC_DROPPED_FRMS        0x28
  57 #define MAC_CONNECTED_CCAT_FLAG 0x78
  58
  59 #define MII_MAC_ADDR            0x8
  60 #define MII_MAC_FILT_FLAG       0xe
  61 #define MII_LINK_STATUS         0xf
  62
  63 #define FIFO_TX_REG             0x0
  64 #define FIFO_TX_RESET           0x8
  65 #define FIFO_RX_REG             0x10
  66 #define FIFO_RX_ADDR_VALID      (1u << 31)
  67 #define FIFO_RX_RESET           0x18
  68
  69 #define DMA_CHAN_OFFSET         0x1000
  70 #define DMA_CHAN_SIZE           0x8
  71
  72 #define DMA_WINDOW_SIZE_MASK    0xfffffffc
  73
  74 #define ETHERCAT_MASTER_ID      0x14
  75
  76 static const struct pci_device_id ids[] = {
  77         { PCI_DEVICE(0x15ec, 0x5000), },
  78         { 0, }
  79 };
  80 MODULE_DEVICE_TABLE(pci, ids);
  81
  82 struct rx_header {
  83 #define RXHDR_NEXT_ADDR_MASK    0xffffffu
  84 #define RXHDR_NEXT_VALID        (1u << 31)
  85         __le32 next;
  86 #define RXHDR_NEXT_RECV_FLAG    0x1
  87         __le32 recv;
  88 #define RXHDR_LEN_MASK          0xfffu
  89         __le16 len;
  90         __le16 port;
  91         __le32 reserved;
  92         u8 timestamp[8];
  93 } __packed;
  94
  95 #define PKT_PAYLOAD_SIZE        0x7e8
  96 struct rx_desc {
  97         struct rx_header header;
  98         u8 data[PKT_PAYLOAD_SIZE];
  99 } __packed;
 100
 101 struct tx_header {
 102         __le16 len;
 103 #define TX_HDR_PORT_0           0x1
 104 #define TX_HDR_PORT_1           0x2
 105         u8 port;
 106         u8 ts_enable;
 107 #define TX_HDR_SENT             0x1
 108         __le32 sent;
 109         u8 timestamp[8];
 110 } __packed;
 111
 112 struct tx_desc {
 113         struct tx_header header;
 114         u8 data[PKT_PAYLOAD_SIZE];
 115 } __packed;
 116
 117 #define FIFO_SIZE               64
 118
 119 static long polling_frequency = TIMER_INTERVAL_NSEC;
 120
 121 struct bhf_dma {
 122         u8 *buf;
 123         size_t len;
 124         dma_addr_t buf_phys;
 125
 126         u8 *alloc;
 127         size_t alloc_len;
 128         dma_addr_t alloc_phys;
 129 };
 130
 131 struct ec_bhf_priv {
 132         struct net_device *net_dev;
 133         struct pci_dev *dev;
 134
 135         void __iomem *io;
 136         void __iomem *dma_io;
 137
 138         struct hrtimer hrtimer;
 139
 140         int tx_dma_chan;
 141         int rx_dma_chan;
 142         void __iomem *ec_io;
 143         void __iomem *fifo_io;
 144         void __iomem *mii_io;
 145         void __iomem *mac_io;
 146
 147         struct bhf_dma rx_buf;
 148         struct rx_desc *rx_descs;
 149         int rx_dnext;
 150         int rx_dcount;
 151
 152         struct bhf_dma tx_buf;
 153         struct tx_desc *tx_descs;
 154         int tx_dcount;
 155         int tx_dnext;
 156
 157         u64 stat_rx_bytes;
 158         u64 stat_tx_bytes;
 159 };
 160
 161 #define PRIV_TO_DEV(priv) (&(priv)->dev->dev)
 162
 163 static void ec_bhf_reset(struct ec_bhf_priv *priv)
 164 {
 165         iowrite8(0, priv->mac_io + MAC_FRAME_ERR_CNT);
 166         iowrite8(0, priv->mac_io + MAC_RX_ERR_CNT);
 167         iowrite8(0, priv->mac_io + MAC_CRC_ERR_CNT);
 168         iowrite8(0, priv->mac_io + MAC_LNK_LST_ERR_CNT);
 169         iowrite32(0, priv->mac_io + MAC_TX_FRAME_CNT);
 170         iowrite32(0, priv->mac_io + MAC_RX_FRAME_CNT);
 171         iowrite8(0, priv->mac_io + MAC_DROPPED_FRMS);
 172
 173         iowrite8(0, priv->fifo_io + FIFO_TX_RESET);
 174         iowrite8(0, priv->fifo_io + FIFO_RX_RESET);
 175
 176         iowrite8(0, priv->mac_io + MAC_TX_FIFO_LVL);
 177 }
 178
 179 static void ec_bhf_send_packet(struct ec_bhf_priv *priv, struct tx_desc *desc)
 180 {
 181         u32 len = le16_to_cpu(desc->header.len) + sizeof(desc->header);
 182         u32 addr = (u8 *)desc - priv->tx_buf.buf;
 183
 184         iowrite32((ALIGN(len, 8) << 24) | addr, priv->fifo_io + FIFO_TX_REG);
 185 }
 186
 187 static int ec_bhf_desc_sent(struct tx_desc *desc)
 188 {
 189         return le32_to_cpu(desc->header.sent) & TX_HDR_SENT;
 190 }
 191
 192 static void ec_bhf_process_tx(struct ec_bhf_priv *priv)
 193 {
 194         if (unlikely(netif_queue_stopped(priv->net_dev))) {
 195                 /* Make sure that we perceive changes to tx_dnext. */
 196                 smp_rmb();
 197
 198                 if (ec_bhf_desc_sent(&priv->tx_descs[priv->tx_dnext]))
 199                         netif_wake_queue(priv->net_dev);
 200         }
 201 }
 202
 203 static int ec_bhf_pkt_received(struct rx_desc *desc)
 204 {
 205         return le32_to_cpu(desc->header.recv) & RXHDR_NEXT_RECV_FLAG;
 206 }
 207
 208 static void ec_bhf_add_rx_desc(struct ec_bhf_priv *priv, struct rx_desc *desc)
 209 {
 210         iowrite32(FIFO_RX_ADDR_VALID | ((u8 *)(desc) - priv->rx_buf.buf),
 211                   priv->fifo_io + FIFO_RX_REG);
 212 }
 213
 214 static void ec_bhf_process_rx(struct ec_bhf_priv *priv)
 215 {
 216         struct rx_desc *desc = &priv->rx_descs[priv->rx_dnext];
 217
 218         while (ec_bhf_pkt_received(desc)) {
 219                 int pkt_size = (le16_to_cpu(desc->header.len) &
 220                                RXHDR_LEN_MASK) - sizeof(struct rx_header) - 4;
 221                 u8 *data = desc->data;
 222                 struct sk_buff *skb;
 223
 224                 skb = netdev_alloc_skb_ip_align(priv->net_dev, pkt_size);
 225                 if (skb) {
 226                         skb_put_data(skb, data, pkt_size);
 227                         skb->protocol = eth_type_trans(skb, priv->net_dev);
 228                         priv->stat_rx_bytes += pkt_size;
 229
 230                         netif_rx(skb);
 231                 } else {
 232                         dev_err_ratelimited(PRIV_TO_DEV(priv),
 233                                             "Couldn't allocate a skb_buff for a packet of size %u\n",
 234                                             pkt_size);
 235                 }
 236
 237                 desc->header.recv = 0;
 238
 239                 ec_bhf_add_rx_desc(priv, desc);
 240
 241                 priv->rx_dnext = (priv->rx_dnext + 1) % priv->rx_dcount;
 242                 desc = &priv->rx_descs[priv->rx_dnext];
 243         }
 244 }
 245
 246 static enum hrtimer_restart ec_bhf_timer_fun(struct hrtimer *timer)
 247 {
 248         struct ec_bhf_priv *priv = container_of(timer, struct ec_bhf_priv,
 249                                                 hrtimer);
 250         ec_bhf_process_rx(priv);
 251         ec_bhf_process_tx(priv);
 252
 253         if (!netif_running(priv->net_dev))
 254                 return HRTIMER_NORESTART;
 255
 256         hrtimer_forward_now(timer, polling_frequency);
 257         return HRTIMER_RESTART;
 258 }
 259
 260 static int ec_bhf_setup_offsets(struct ec_bhf_priv *priv)
 261 {
 262         struct device *dev = PRIV_TO_DEV(priv);
 263         unsigned block_count, i;
 264         void __iomem *ec_info;
 265
 266         block_count = ioread8(priv->io + INFO_BLOCK_BLK_CNT);
 267         for (i = 0; i < block_count; i++) {
 268                 u16 type = ioread16(priv->io + i * INFO_BLOCK_SIZE +
 269                                     INFO_BLOCK_TYPE);
 270                 if (type == ETHERCAT_MASTER_ID)
 271                         break;
 272         }
 273         if (i == block_count) {
 274                 dev_err(dev, "EtherCAT master with DMA block not found\n");
 275                 return -ENODEV;
 276         }
 277
 278         ec_info = priv->io + i * INFO_BLOCK_SIZE;
 279
 280         priv->tx_dma_chan = ioread8(ec_info + INFO_BLOCK_TX_CHAN);
 281         priv->rx_dma_chan = ioread8(ec_info + INFO_BLOCK_RX_CHAN);
 282
 283         priv->ec_io = priv->io + ioread32(ec_info + INFO_BLOCK_OFFSET);
 284         priv->mii_io = priv->ec_io + ioread32(priv->ec_io + EC_MII_OFFSET);
 285         priv->fifo_io = priv->ec_io + ioread32(priv->ec_io + EC_FIFO_OFFSET);
 286         priv->mac_io = priv->ec_io + ioread32(priv->ec_io + EC_MAC_OFFSET);
 287
 288         return 0;
 289 }
 290
 291 static netdev_tx_t ec_bhf_start_xmit(struct sk_buff *skb,
 292                                      struct net_device *net_dev)
 293 {
 294         struct ec_bhf_priv *priv = netdev_priv(net_dev);
 295         struct tx_desc *desc;
 296         unsigned len;
 297
 298         desc = &priv->tx_descs[priv->tx_dnext];
 299
 300         skb_copy_and_csum_dev(skb, desc->data);
 301         len = skb->len;
 302
 303         memset(&desc->header, 0, sizeof(desc->header));
 304         desc->header.len = cpu_to_le16(len);
 305         desc->header.port = TX_HDR_PORT_0;
 306
 307         ec_bhf_send_packet(priv, desc);
 308
 309         priv->tx_dnext = (priv->tx_dnext + 1) % priv->tx_dcount;
 310
 311         if (!ec_bhf_desc_sent(&priv->tx_descs[priv->tx_dnext])) {
 312                 /* Make sure that updates to tx_dnext are perceived
 313                  * by timer routine.
 314                  */
 315                 smp_wmb();
 316
 317                 netif_stop_queue(net_dev);
 318         }
 319
 320         priv->stat_tx_bytes += len;
 321
 322         dev_kfree_skb(skb);
 323
 324         return NETDEV_TX_OK;
 325 }
 326
 327 static int ec_bhf_alloc_dma_mem(struct ec_bhf_priv *priv,
 328                                 struct bhf_dma *buf,
 329                                 int channel,
 330                                 int size)
 331 {
 332         int offset = channel * DMA_CHAN_SIZE + DMA_CHAN_OFFSET;
 333         struct device *dev = PRIV_TO_DEV(priv);
 334         u32 mask;
 335
 336         iowrite32(0xffffffff, priv->dma_io + offset);
 337
 338         mask = ioread32(priv->dma_io + offset);
 339         mask &= DMA_WINDOW_SIZE_MASK;
 340
 341         /* We want to allocate a chunk of memory that is:
 342          * - aligned to the mask we just read
 343          * - is of size 2^mask bytes (at most)
 344          * In order to ensure that we will allocate buffer of
 345          * 2 * 2^mask bytes.
 346          */
 347         buf->len = min_t(int, ~mask + 1, size);
 348         buf->alloc_len = 2 * buf->len;
 349
 350         buf->alloc = dma_alloc_coherent(dev, buf->alloc_len, &buf->alloc_phys,
 351                                         GFP_KERNEL);
 352         if (buf->alloc == NULL) {
 353                 dev_err(dev, "Failed to allocate buffer\n");
 354                 return -ENOMEM;
 355         }
 356
 357         buf->buf_phys = (buf->alloc_phys + buf->len) & mask;
 358         buf->buf = buf->alloc + (buf->buf_phys - buf->alloc_phys);
 359
 360         iowrite32(0, priv->dma_io + offset + 4);
 361         iowrite32(buf->buf_phys, priv->dma_io + offset);
 362
 363         return 0;
 364 }
 365
 366 static void ec_bhf_setup_tx_descs(struct ec_bhf_priv *priv)
 367 {
 368         int i = 0;
 369
 370         priv->tx_dcount = priv->tx_buf.len / sizeof(struct tx_desc);
 371         priv->tx_descs = (struct tx_desc *)priv->tx_buf.buf;
 372         priv->tx_dnext = 0;
 373
 374         for (i = 0; i < priv->tx_dcount; i++)
 375                 priv->tx_descs[i].header.sent = cpu_to_le32(TX_HDR_SENT);
 376 }
 377
 378 static void ec_bhf_setup_rx_descs(struct ec_bhf_priv *priv)
 379 {
 380         int i;
 381
 382         priv->rx_dcount = priv->rx_buf.len / sizeof(struct rx_desc);
 383         priv->rx_descs = (struct rx_desc *)priv->rx_buf.buf;
 384         priv->rx_dnext = 0;
 385
 386         for (i = 0; i < priv->rx_dcount; i++) {
 387                 struct rx_desc *desc = &priv->rx_descs[i];
 388                 u32 next;
 389
 390                 if (i != priv->rx_dcount - 1)
 391                         next = (u8 *)(desc + 1) - priv->rx_buf.buf;
 392                 else
 393                         next = 0;
 394                 next |= RXHDR_NEXT_VALID;
 395                 desc->header.next = cpu_to_le32(next);
 396                 desc->header.recv = 0;
 397                 ec_bhf_add_rx_desc(priv, desc);
 398         }
 399 }
 400
 401 static int ec_bhf_open(struct net_device *net_dev)
 402 {
 403         struct ec_bhf_priv *priv = netdev_priv(net_dev);
 404         struct device *dev = PRIV_TO_DEV(priv);
 405         int err = 0;
 406
 407         ec_bhf_reset(priv);
 408
 409         err = ec_bhf_alloc_dma_mem(priv, &priv->rx_buf, priv->rx_dma_chan,
 410                                    FIFO_SIZE * sizeof(struct rx_desc));
 411         if (err) {
 412                 dev_err(dev, "Failed to allocate rx buffer\n");
 413                 goto out;
 414         }
 415         ec_bhf_setup_rx_descs(priv);
 416
 417         err = ec_bhf_alloc_dma_mem(priv, &priv->tx_buf, priv->tx_dma_chan,
 418                                    FIFO_SIZE * sizeof(struct tx_desc));
 419         if (err) {
 420                 dev_err(dev, "Failed to allocate tx buffer\n");
 421                 goto error_rx_free;
 422         }
 423         iowrite8(0, priv->mii_io + MII_MAC_FILT_FLAG);
 424         ec_bhf_setup_tx_descs(priv);
 425
 426         netif_start_queue(net_dev);
 427
 428         hrtimer_init(&priv->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 429         priv->hrtimer.function = ec_bhf_timer_fun;
 430         hrtimer_start(&priv->hrtimer, polling_frequency, HRTIMER_MODE_REL);
 431
 432         return 0;
 433
 434 error_rx_free:
 435         dma_free_coherent(dev, priv->rx_buf.alloc_len, priv->rx_buf.alloc,
 436                           priv->rx_buf.alloc_len);
 437 out:
 438         return err;
 439 }
 440
 441 static int ec_bhf_stop(struct net_device *net_dev)
 442 {
 443         struct ec_bhf_priv *priv = netdev_priv(net_dev);
 444         struct device *dev = PRIV_TO_DEV(priv);
 445
 446         hrtimer_cancel(&priv->hrtimer);
 447
 448         ec_bhf_reset(priv);
 449
 450         netif_tx_disable(net_dev);
 451
 452         dma_free_coherent(dev, priv->tx_buf.alloc_len,
 453                           priv->tx_buf.alloc, priv->tx_buf.alloc_phys);
 454         dma_free_coherent(dev, priv->rx_buf.alloc_len,
 455                           priv->rx_buf.alloc, priv->rx_buf.alloc_phys);
 456
 457         return 0;
 458 }
 459
 460 static void
 461 ec_bhf_get_stats(struct net_device *net_dev,
 462                  struct rtnl_link_stats64 *stats)
 463 {
 464         struct ec_bhf_priv *priv = netdev_priv(net_dev);
 465
 466         stats->rx_errors = ioread8(priv->mac_io + MAC_RX_ERR_CNT) +
 467                                 ioread8(priv->mac_io + MAC_CRC_ERR_CNT) +
 468                                 ioread8(priv->mac_io + MAC_FRAME_ERR_CNT);
 469         stats->rx_packets = ioread32(priv->mac_io + MAC_RX_FRAME_CNT);
 470         stats->tx_packets = ioread32(priv->mac_io + MAC_TX_FRAME_CNT);
 471         stats->rx_dropped = ioread8(priv->mac_io + MAC_DROPPED_FRMS);
 472
 473         stats->tx_bytes = priv->stat_tx_bytes;
 474         stats->rx_bytes = priv->stat_rx_bytes;
 475 }
 476
 477 static const struct net_device_ops ec_bhf_netdev_ops = {
 478         .ndo_start_xmit         = ec_bhf_start_xmit,
 479         .ndo_open               = ec_bhf_open,
 480         .ndo_stop               = ec_bhf_stop,
 481         .ndo_get_stats64        = ec_bhf_get_stats,
 482         .ndo_validate_addr      = eth_validate_addr,
 483         .ndo_set_mac_address    = eth_mac_addr
 484 };
 485
 486 static int ec_bhf_probe(struct pci_dev *dev, const struct pci_device_id *id)
 487 {
 488         struct net_device *net_dev;
 489         struct ec_bhf_priv *priv;
 490         void __iomem *dma_io;
 491         void __iomem *io;
 492         int err = 0;
 493
 494         err = pci_enable_device(dev);
 495         if (err)
 496                 return err;
 497
 498         pci_set_master(dev);
 499
 500         err = pci_set_dma_mask(dev, DMA_BIT_MASK(32));
 501         if (err) {
 502                 dev_err(&dev->dev,
 503                         "Required dma mask not supported, failed to initialize device\n");
 504                 err = -EIO;
 505                 goto err_disable_dev;
 506         }
 507
 508         err = pci_set_consistent_dma_mask(dev, DMA_BIT_MASK(32));
 509         if (err) {
 510                 dev_err(&dev->dev,
 511                         "Required dma mask not supported, failed to initialize device\n");
 512                 goto err_disable_dev;
 513         }
 514
 515         err = pci_request_regions(dev, "ec_bhf");
 516         if (err) {
 517                 dev_err(&dev->dev, "Failed to request pci memory regions\n");
 518                 goto err_disable_dev;
 519         }
 520
 521         io = pci_iomap(dev, 0, 0);
 522         if (!io) {
 523                 dev_err(&dev->dev, "Failed to map pci card memory bar 0");
 524                 err = -EIO;
 525                 goto err_release_regions;
 526         }
 527
 528         dma_io = pci_iomap(dev, 2, 0);
 529         if (!dma_io) {
 530                 dev_err(&dev->dev, "Failed to map pci card memory bar 2");
 531                 err = -EIO;
 532                 goto err_unmap;
 533         }
 534
 535         net_dev = alloc_etherdev(sizeof(struct ec_bhf_priv));
 536         if (net_dev == NULL) {
 537                 err = -ENOMEM;
 538                 goto err_unmap_dma_io;
 539         }
 540
 541         pci_set_drvdata(dev, net_dev);
 542         SET_NETDEV_DEV(net_dev, &dev->dev);
 543
 544         net_dev->features = 0;
 545         net_dev->flags |= IFF_NOARP;
 546
 547         net_dev->netdev_ops = &ec_bhf_netdev_ops;
 548
 549         priv = netdev_priv(net_dev);
 550         priv->net_dev = net_dev;
 551         priv->io = io;
 552         priv->dma_io = dma_io;
 553         priv->dev = dev;
 554
 555         err = ec_bhf_setup_offsets(priv);
 556         if (err < 0)
 557                 goto err_free_net_dev;
 558
 559         memcpy_fromio(net_dev->dev_addr, priv->mii_io + MII_MAC_ADDR, 6);
 560
 561         err = register_netdev(net_dev);
 562         if (err < 0)
 563                 goto err_free_net_dev;
 564
 565         return 0;
 566
 567 err_free_net_dev:
 568         free_netdev(net_dev);
 569 err_unmap_dma_io:
 570         pci_iounmap(dev, dma_io);
 571 err_unmap:
 572         pci_iounmap(dev, io);
 573 err_release_regions:
 574         pci_release_regions(dev);
 575 err_disable_dev:
 576         pci_clear_master(dev);
 577         pci_disable_device(dev);
 578
 579         return err;
 580 }
 581
 582 static void ec_bhf_remove(struct pci_dev *dev)
 583 {
 584         struct net_device *net_dev = pci_get_drvdata(dev);
 585         struct ec_bhf_priv *priv = netdev_priv(net_dev);
 586
 587         unregister_netdev(net_dev);
 588         free_netdev(net_dev);
 589
 590         pci_iounmap(dev, priv->dma_io);
 591         pci_iounmap(dev, priv->io);
 592         pci_release_regions(dev);
 593         pci_clear_master(dev);
 594         pci_disable_device(dev);
 595 }
 596
 597 static struct pci_driver pci_driver = {
 598         .name           = "ec_bhf",
 599         .id_table       = ids,
 600         .probe          = ec_bhf_probe,
 601         .remove         = ec_bhf_remove,
 602 };
 603 module_pci_driver(pci_driver);
 604
 605 module_param(polling_frequency, long, 0444);
 606 MODULE_PARM_DESC(polling_frequency, "Polling timer frequency in ns");
 607
 608 MODULE_LICENSE("GPL");
 609 MODULE_AUTHOR("Dariusz Marcinkiewicz <reksio@newterm.pl>");