drivers/net/ethernet/qualcomm/qca_spi.c

   1 /*
   2  *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
   3  *   Copyright (c) 2014, I2SE GmbH
   4  *
   5  *   Permission to use, copy, modify, and/or distribute this software
   6  *   for any purpose with or without fee is hereby granted, provided
   7  *   that the above copyright notice and this permission notice appear
   8  *   in all copies.
   9  *
  10  *   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
  11  *   WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
  12  *   WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
  13  *   THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
  14  *   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  15  *   LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
  16  *   NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  17  *   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /*   This module implements the Qualcomm Atheros SPI protocol for
  21  *   kernel-based SPI device; it is essentially an Ethernet-to-SPI
  22  *   serial converter;
  23  */
  24
  25 #include <linux/errno.h>
  26 #include <linux/etherdevice.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/if_ether.h>
  29 #include <linux/init.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/jiffies.h>
  32 #include <linux/kernel.h>
  33 #include <linux/kthread.h>
  34 #include <linux/module.h>
  35 #include <linux/moduleparam.h>
  36 #include <linux/netdevice.h>
  37 #include <linux/of.h>
  38 #include <linux/of_device.h>
  39 #include <linux/of_net.h>
  40 #include <linux/sched.h>
  41 #include <linux/skbuff.h>
  42 #include <linux/spi/spi.h>
  43 #include <linux/types.h>
  44
  45 #include "qca_7k.h"
  46 #include "qca_debug.h"
  47 #include "qca_framing.h"
  48 #include "qca_spi.h"
  49
  50 #define MAX_DMA_BURST_LEN 5000
  51
  52 /*   Modules parameters     */
  53 #define QCASPI_CLK_SPEED_MIN 1000000
  54 #define QCASPI_CLK_SPEED_MAX 16000000
  55 #define QCASPI_CLK_SPEED     8000000
  56 static int qcaspi_clkspeed;
  57 module_param(qcaspi_clkspeed, int, 0);
  58 MODULE_PARM_DESC(qcaspi_clkspeed, "SPI bus clock speed (Hz). Use 1000000-16000000.");
  59
  60 #define QCASPI_BURST_LEN_MIN 1
  61 #define QCASPI_BURST_LEN_MAX MAX_DMA_BURST_LEN
  62 static int qcaspi_burst_len = MAX_DMA_BURST_LEN;
  63 module_param(qcaspi_burst_len, int, 0);
  64 MODULE_PARM_DESC(qcaspi_burst_len, "Number of data bytes per burst. Use 1-5000.");
  65
  66 #define QCASPI_PLUGGABLE_MIN 0
  67 #define QCASPI_PLUGGABLE_MAX 1
  68 static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;
  69 module_param(qcaspi_pluggable, int, 0);
  70 MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");
  71
  72 #define QCASPI_MTU QCAFRM_ETHMAXMTU
  73 #define QCASPI_TX_TIMEOUT (1 * HZ)
  74 #define QCASPI_QCA7K_REBOOT_TIME_MS 1000
  75
  76 static void
  77 start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)
  78 {
  79         *intr_cause = 0;
  80
  81         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
  82         qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
  83         netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);
  84 }
  85
  86 static void
  87 end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)
  88 {
  89         u16 intr_enable = (SPI_INT_CPU_ON |
  90                            SPI_INT_PKT_AVLBL |
  91                            SPI_INT_RDBUF_ERR |
  92                            SPI_INT_WRBUF_ERR);
  93
  94         qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
  95         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable);
  96         netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);
  97 }
  98
  99 static u32
 100 qcaspi_write_burst(struct qcaspi *qca, u8 *src, u32 len)
 101 {
 102         __be16 cmd;
 103         struct spi_message *msg = &qca->spi_msg2;
 104         struct spi_transfer *transfer = &qca->spi_xfer2[0];
 105         int ret;
 106
 107         cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 108         transfer->tx_buf = &cmd;
 109         transfer->rx_buf = NULL;
 110         transfer->len = QCASPI_CMD_LEN;
 111         transfer = &qca->spi_xfer2[1];
 112         transfer->tx_buf = src;
 113         transfer->rx_buf = NULL;
 114         transfer->len = len;
 115
 116         ret = spi_sync(qca->spi_dev, msg);
 117
 118         if (ret || (msg->actual_length != QCASPI_CMD_LEN + len)) {
 119                 qcaspi_spi_error(qca);
 120                 return 0;
 121         }
 122
 123         return len;
 124 }
 125
 126 static u32
 127 qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)
 128 {
 129         struct spi_message *msg = &qca->spi_msg1;
 130         struct spi_transfer *transfer = &qca->spi_xfer1;
 131         int ret;
 132
 133         transfer->tx_buf = src;
 134         transfer->rx_buf = NULL;
 135         transfer->len = len;
 136
 137         ret = spi_sync(qca->spi_dev, msg);
 138
 139         if (ret || (msg->actual_length != len)) {
 140                 qcaspi_spi_error(qca);
 141                 return 0;
 142         }
 143
 144         return len;
 145 }
 146
 147 static u32
 148 qcaspi_read_burst(struct qcaspi *qca, u8 *dst, u32 len)
 149 {
 150         struct spi_message *msg = &qca->spi_msg2;
 151         __be16 cmd;
 152         struct spi_transfer *transfer = &qca->spi_xfer2[0];
 153         int ret;
 154
 155         cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 156         transfer->tx_buf = &cmd;
 157         transfer->rx_buf = NULL;
 158         transfer->len = QCASPI_CMD_LEN;
 159         transfer = &qca->spi_xfer2[1];
 160         transfer->tx_buf = NULL;
 161         transfer->rx_buf = dst;
 162         transfer->len = len;
 163
 164         ret = spi_sync(qca->spi_dev, msg);
 165
 166         if (ret || (msg->actual_length != QCASPI_CMD_LEN + len)) {
 167                 qcaspi_spi_error(qca);
 168                 return 0;
 169         }
 170
 171         return len;
 172 }
 173
 174 static u32
 175 qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)
 176 {
 177         struct spi_message *msg = &qca->spi_msg1;
 178         struct spi_transfer *transfer = &qca->spi_xfer1;
 179         int ret;
 180
 181         transfer->tx_buf = NULL;
 182         transfer->rx_buf = dst;
 183         transfer->len = len;
 184
 185         ret = spi_sync(qca->spi_dev, msg);
 186
 187         if (ret || (msg->actual_length != len)) {
 188                 qcaspi_spi_error(qca);
 189                 return 0;
 190         }
 191
 192         return len;
 193 }
 194
 195 static int
 196 qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
 197 {
 198         u32 count;
 199         u32 written;
 200         u32 offset;
 201         u32 len;
 202
 203         len = skb->len;
 204
 205         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len);
 206         if (qca->legacy_mode)
 207                 qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 208
 209         offset = 0;
 210         while (len) {
 211                 count = len;
 212                 if (count > qca->burst_len)
 213                         count = qca->burst_len;
 214
 215                 if (qca->legacy_mode) {
 216                         written = qcaspi_write_legacy(qca,
 217                                                       skb->data + offset,
 218                                                       count);
 219                 } else {
 220                         written = qcaspi_write_burst(qca,
 221                                                      skb->data + offset,
 222                                                      count);
 223                 }
 224
 225                 if (written != count)
 226                         return -1;
 227
 228                 offset += count;
 229                 len -= count;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static int
 236 qcaspi_transmit(struct qcaspi *qca)
 237 {
 238         struct net_device_stats *n_stats = &qca->net_dev->stats;
 239         u16 available = 0;
 240         u32 pkt_len;
 241         u16 new_head;
 242         u16 packets = 0;
 243
 244         if (qca->txr.skb[qca->txr.head] == NULL)
 245                 return 0;
 246
 247         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, &available);
 248
 249         while (qca->txr.skb[qca->txr.head]) {
 250                 pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;
 251
 252                 if (available < pkt_len) {
 253                         if (packets == 0)
 254                                 qca->stats.write_buf_miss++;
 255                         break;
 256                 }
 257
 258                 if (qcaspi_tx_frame(qca, qca->txr.skb[qca->txr.head]) == -1) {
 259                         qca->stats.write_err++;
 260                         return -1;
 261                 }
 262
 263                 packets++;
 264                 n_stats->tx_packets++;
 265                 n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;
 266                 available -= pkt_len;
 267
 268                 /* remove the skb from the queue */
 269                 /* XXX After inconsistent lock states netif_tx_lock()
 270                  * has been replaced by netif_tx_lock_bh() and so on.
 271                  */
 272                 netif_tx_lock_bh(qca->net_dev);
 273                 dev_kfree_skb(qca->txr.skb[qca->txr.head]);
 274                 qca->txr.skb[qca->txr.head] = NULL;
 275                 qca->txr.size -= pkt_len;
 276                 new_head = qca->txr.head + 1;
 277                 if (new_head >= qca->txr.count)
 278                         new_head = 0;
 279                 qca->txr.head = new_head;
 280                 if (netif_queue_stopped(qca->net_dev))
 281                         netif_wake_queue(qca->net_dev);
 282                 netif_tx_unlock_bh(qca->net_dev);
 283         }
 284
 285         return 0;
 286 }
 287
 288 static int
 289 qcaspi_receive(struct qcaspi *qca)
 290 {
 291         struct net_device *net_dev = qca->net_dev;
 292         struct net_device_stats *n_stats = &net_dev->stats;
 293         u16 available = 0;
 294         u32 bytes_read;
 295         u8 *cp;
 296
 297         /* Allocate rx SKB if we don't have one available. */
 298         if (!qca->rx_skb) {
 299                 qca->rx_skb = netdev_alloc_skb(net_dev,
 300                                                net_dev->mtu + VLAN_ETH_HLEN);
 301                 if (!qca->rx_skb) {
 302                         netdev_dbg(net_dev, "out of RX resources\n");
 303                         qca->stats.out_of_mem++;
 304                         return -1;
 305                 }
 306         }
 307
 308         /* Read the packet size. */
 309         qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);
 310         netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %08x\n",
 311                    available);
 312
 313         if (available == 0) {
 314                 netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");
 315                 return -1;
 316         }
 317
 318         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available);
 319
 320         if (qca->legacy_mode)
 321                 qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 322
 323         while (available) {
 324                 u32 count = available;
 325
 326                 if (count > qca->burst_len)
 327                         count = qca->burst_len;
 328
 329                 if (qca->legacy_mode) {
 330                         bytes_read = qcaspi_read_legacy(qca, qca->rx_buffer,
 331                                                         count);
 332                 } else {
 333                         bytes_read = qcaspi_read_burst(qca, qca->rx_buffer,
 334                                                        count);
 335                 }
 336
 337                 netdev_dbg(net_dev, "available: %d, byte read: %d\n",
 338                            available, bytes_read);
 339
 340                 if (bytes_read) {
 341                         available -= bytes_read;
 342                 } else {
 343                         qca->stats.read_err++;
 344                         return -1;
 345                 }
 346
 347                 cp = qca->rx_buffer;
 348
 349                 while ((bytes_read--) && (qca->rx_skb)) {
 350                         s32 retcode;
 351
 352                         retcode = qcafrm_fsm_decode(&qca->frm_handle,
 353                                                     qca->rx_skb->data,
 354                                                     skb_tailroom(qca->rx_skb),
 355                                                     *cp);
 356                         cp++;
 357                         switch (retcode) {
 358                         case QCAFRM_GATHER:
 359                         case QCAFRM_NOHEAD:
 360                                 break;
 361                         case QCAFRM_NOTAIL:
 362                                 netdev_dbg(net_dev, "no RX tail\n");
 363                                 n_stats->rx_errors++;
 364                                 n_stats->rx_dropped++;
 365                                 break;
 366                         case QCAFRM_INVLEN:
 367                                 netdev_dbg(net_dev, "invalid RX length\n");
 368                                 n_stats->rx_errors++;
 369                                 n_stats->rx_dropped++;
 370                                 break;
 371                         default:
 372                                 qca->rx_skb->dev = qca->net_dev;
 373                                 n_stats->rx_packets++;
 374                                 n_stats->rx_bytes += retcode;
 375                                 skb_put(qca->rx_skb, retcode);
 376                                 qca->rx_skb->protocol = eth_type_trans(
 377                                         qca->rx_skb, qca->rx_skb->dev);
 378                                 qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
 379                                 netif_rx_ni(qca->rx_skb);
 380                                 qca->rx_skb = netdev_alloc_skb(net_dev,
 381                                         net_dev->mtu + VLAN_ETH_HLEN);
 382                                 if (!qca->rx_skb) {
 383                                         netdev_dbg(net_dev, "out of RX resources\n");
 384                                         n_stats->rx_errors++;
 385                                         qca->stats.out_of_mem++;
 386                                         break;
 387                                 }
 388                         }
 389                 }
 390         }
 391
 392         return 0;
 393 }
 394
 395 /*   Check that tx ring stores only so much bytes
 396  *   that fit into the internal QCA buffer.
 397  */
 398
 399 static int
 400 qcaspi_tx_ring_has_space(struct tx_ring *txr)
 401 {
 402         if (txr->skb[txr->tail])
 403                 return 0;
 404
 405         return (txr->size + QCAFRM_ETHMAXLEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
 406 }
 407
 408 /*   Flush the tx ring. This function is only safe to
 409  *   call from the qcaspi_spi_thread.
 410  */
 411
 412 static void
 413 qcaspi_flush_tx_ring(struct qcaspi *qca)
 414 {
 415         int i;
 416
 417         /* XXX After inconsistent lock states netif_tx_lock()
 418          * has been replaced by netif_tx_lock_bh() and so on.
 419          */
 420         netif_tx_lock_bh(qca->net_dev);
 421         for (i = 0; i < TX_RING_MAX_LEN; i++) {
 422                 if (qca->txr.skb[i]) {
 423                         dev_kfree_skb(qca->txr.skb[i]);
 424                         qca->txr.skb[i] = NULL;
 425                         qca->net_dev->stats.tx_dropped++;
 426                 }
 427         }
 428         qca->txr.tail = 0;
 429         qca->txr.head = 0;
 430         qca->txr.size = 0;
 431         netif_tx_unlock_bh(qca->net_dev);
 432 }
 433
 434 static void
 435 qcaspi_qca7k_sync(struct qcaspi *qca, int event)
 436 {
 437         u16 signature = 0;
 438         u16 spi_config;
 439         u16 wrbuf_space = 0;
 440         static u16 reset_count;
 441
 442         if (event == QCASPI_EVENT_CPUON) {
 443                 /* Read signature twice, if not valid
 444                  * go back to unknown state.
 445                  */
 446                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 447                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 448                 if (signature != QCASPI_GOOD_SIGNATURE) {
 449                         qca->sync = QCASPI_SYNC_UNKNOWN;
 450                         netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");
 451                 } else {
 452                         /* ensure that the WRBUF is empty */
 453                         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,
 454                                              &wrbuf_space);
 455                         if (wrbuf_space != QCASPI_HW_BUF_LEN) {
 456                                 netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");
 457                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 458                         } else {
 459                                 netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");
 460                                 qca->sync = QCASPI_SYNC_READY;
 461                                 return;
 462                         }
 463                 }
 464         }
 465
 466         switch (qca->sync) {
 467         case QCASPI_SYNC_READY:
 468                 /* Read signature, if not valid go to unknown state. */
 469                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 470                 if (signature != QCASPI_GOOD_SIGNATURE) {
 471                         qca->sync = QCASPI_SYNC_UNKNOWN;
 472                         netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");
 473                         /* don't reset right away */
 474                         return;
 475                 }
 476                 break;
 477         case QCASPI_SYNC_UNKNOWN:
 478                 /* Read signature, if not valid stay in unknown state */
 479                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 480                 if (signature != QCASPI_GOOD_SIGNATURE) {
 481                         netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");
 482                         return;
 483                 }
 484
 485                 /* TODO: use GPIO to reset QCA7000 in legacy mode*/
 486                 netdev_dbg(qca->net_dev, "sync: resetting device.\n");
 487                 qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);
 488                 spi_config |= QCASPI_SLAVE_RESET_BIT;
 489                 qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config);
 490
 491                 qca->sync = QCASPI_SYNC_RESET;
 492                 qca->stats.trig_reset++;
 493                 reset_count = 0;
 494                 break;
 495         case QCASPI_SYNC_RESET:
 496                 reset_count++;
 497                 netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",
 498                            reset_count);
 499                 if (reset_count >= QCASPI_RESET_TIMEOUT) {
 500                         /* reset did not seem to take place, try again */
 501                         qca->sync = QCASPI_SYNC_UNKNOWN;
 502                         qca->stats.reset_timeout++;
 503                         netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");
 504                 }
 505                 break;
 506         }
 507 }
 508
 509 static int
 510 qcaspi_spi_thread(void *data)
 511 {
 512         struct qcaspi *qca = data;
 513         u16 intr_cause = 0;
 514
 515         netdev_info(qca->net_dev, "SPI thread created\n");
 516         while (!kthread_should_stop()) {
 517                 set_current_state(TASK_INTERRUPTIBLE);
 518                 if ((qca->intr_req == qca->intr_svc) &&
 519                     (qca->txr.skb[qca->txr.head] == NULL) &&
 520                     (qca->sync == QCASPI_SYNC_READY))
 521                         schedule();
 522
 523                 set_current_state(TASK_RUNNING);
 524
 525                 netdev_dbg(qca->net_dev, "have work to do. int: %d, tx_skb: %p\n",
 526                            qca->intr_req - qca->intr_svc,
 527                            qca->txr.skb[qca->txr.head]);
 528
 529                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
 530
 531                 if (qca->sync != QCASPI_SYNC_READY) {
 532                         netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",
 533                                    (unsigned int)qca->sync);
 534                         netif_stop_queue(qca->net_dev);
 535                         netif_carrier_off(qca->net_dev);
 536                         qcaspi_flush_tx_ring(qca);
 537                         msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
 538                 }
 539
 540                 if (qca->intr_svc != qca->intr_req) {
 541                         qca->intr_svc = qca->intr_req;
 542                         start_spi_intr_handling(qca, &intr_cause);
 543
 544                         if (intr_cause & SPI_INT_CPU_ON) {
 545                                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);
 546
 547                                 /* not synced. */
 548                                 if (qca->sync != QCASPI_SYNC_READY)
 549                                         continue;
 550
 551                                 qca->stats.device_reset++;
 552                                 netif_wake_queue(qca->net_dev);
 553                                 netif_carrier_on(qca->net_dev);
 554                         }
 555
 556                         if (intr_cause & SPI_INT_RDBUF_ERR) {
 557                                 /* restart sync */
 558                                 netdev_dbg(qca->net_dev, "===> rdbuf error!\n");
 559                                 qca->stats.read_buf_err++;
 560                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 561                                 continue;
 562                         }
 563
 564                         if (intr_cause & SPI_INT_WRBUF_ERR) {
 565                                 /* restart sync */
 566                                 netdev_dbg(qca->net_dev, "===> wrbuf error!\n");
 567                                 qca->stats.write_buf_err++;
 568                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 569                                 continue;
 570                         }
 571
 572                         /* can only handle other interrupts
 573                          * if sync has occurred
 574                          */
 575                         if (qca->sync == QCASPI_SYNC_READY) {
 576                                 if (intr_cause & SPI_INT_PKT_AVLBL)
 577                                         qcaspi_receive(qca);
 578                         }
 579
 580                         end_spi_intr_handling(qca, intr_cause);
 581                 }
 582
 583                 if (qca->sync == QCASPI_SYNC_READY)
 584                         qcaspi_transmit(qca);
 585         }
 586         set_current_state(TASK_RUNNING);
 587         netdev_info(qca->net_dev, "SPI thread exit\n");
 588
 589         return 0;
 590 }
 591
 592 static irqreturn_t
 593 qcaspi_intr_handler(int irq, void *data)
 594 {
 595         struct qcaspi *qca = data;
 596
 597         qca->intr_req++;
 598         if (qca->spi_thread &&
 599             qca->spi_thread->state != TASK_RUNNING)
 600                 wake_up_process(qca->spi_thread);
 601
 602         return IRQ_HANDLED;
 603 }
 604
 605 int
 606 qcaspi_netdev_open(struct net_device *dev)
 607 {
 608         struct qcaspi *qca = netdev_priv(dev);
 609         int ret = 0;
 610
 611         if (!qca)
 612                 return -EINVAL;
 613
 614         qca->intr_req = 1;
 615         qca->intr_svc = 0;
 616         qca->sync = QCASPI_SYNC_UNKNOWN;
 617         qcafrm_fsm_init(&qca->frm_handle);
 618
 619         qca->spi_thread = kthread_run((void *)qcaspi_spi_thread,
 620                                       qca, "%s", dev->name);
 621
 622         if (IS_ERR(qca->spi_thread)) {
 623                 netdev_err(dev, "%s: unable to start kernel thread.\n",
 624                            QCASPI_DRV_NAME);
 625                 return PTR_ERR(qca->spi_thread);
 626         }
 627
 628         ret = request_irq(qca->spi_dev->irq, qcaspi_intr_handler, 0,
 629                           dev->name, qca);
 630         if (ret) {
 631                 netdev_err(dev, "%s: unable to get IRQ %d (irqval=%d).\n",
 632                            QCASPI_DRV_NAME, qca->spi_dev->irq, ret);
 633                 kthread_stop(qca->spi_thread);
 634                 return ret;
 635         }
 636
 637         netif_start_queue(qca->net_dev);
 638
 639         return 0;
 640 }
 641
 642 int
 643 qcaspi_netdev_close(struct net_device *dev)
 644 {
 645         struct qcaspi *qca = netdev_priv(dev);
 646
 647         netif_stop_queue(dev);
 648
 649         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
 650         free_irq(qca->spi_dev->irq, qca);
 651
 652         kthread_stop(qca->spi_thread);
 653         qca->spi_thread = NULL;
 654         qcaspi_flush_tx_ring(qca);
 655
 656         return 0;
 657 }
 658
 659 static netdev_tx_t
 660 qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
 661 {
 662         u32 frame_len;
 663         u8 *ptmp;
 664         struct qcaspi *qca = netdev_priv(dev);
 665         u16 new_tail;
 666         struct sk_buff *tskb;
 667         u8 pad_len = 0;
 668
 669         if (skb->len < QCAFRM_ETHMINLEN)
 670                 pad_len = QCAFRM_ETHMINLEN - skb->len;
 671
 672         if (qca->txr.skb[qca->txr.tail]) {
 673                 netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");
 674                 netif_stop_queue(qca->net_dev);
 675                 qca->stats.ring_full++;
 676                 return NETDEV_TX_BUSY;
 677         }
 678
 679         if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||
 680             (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {
 681                 tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,
 682                                        QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);
 683                 if (!tskb) {
 684                         netdev_dbg(qca->net_dev, "could not allocate tx_buff\n");
 685                         qca->stats.out_of_mem++;
 686                         return NETDEV_TX_BUSY;
 687                 }
 688                 dev_kfree_skb(skb);
 689                 skb = tskb;
 690         }
 691
 692         frame_len = skb->len + pad_len;
 693
 694         ptmp = skb_push(skb, QCAFRM_HEADER_LEN);
 695         qcafrm_create_header(ptmp, frame_len);
 696
 697         if (pad_len) {
 698                 ptmp = skb_put(skb, pad_len);
 699                 memset(ptmp, 0, pad_len);
 700         }
 701
 702         ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);
 703         qcafrm_create_footer(ptmp);
 704
 705         netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",
 706                    skb->len);
 707
 708         qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;
 709
 710         new_tail = qca->txr.tail + 1;
 711         if (new_tail >= qca->txr.count)
 712                 new_tail = 0;
 713
 714         qca->txr.skb[qca->txr.tail] = skb;
 715         qca->txr.tail = new_tail;
 716
 717         if (!qcaspi_tx_ring_has_space(&qca->txr)) {
 718                 netif_stop_queue(qca->net_dev);
 719                 qca->stats.ring_full++;
 720         }
 721
 722         dev->trans_start = jiffies;
 723
 724         if (qca->spi_thread &&
 725             qca->spi_thread->state != TASK_RUNNING)
 726                 wake_up_process(qca->spi_thread);
 727
 728         return NETDEV_TX_OK;
 729 }
 730
 731 static void
 732 qcaspi_netdev_tx_timeout(struct net_device *dev)
 733 {
 734         struct qcaspi *qca = netdev_priv(dev);
 735
 736         netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
 737                     jiffies, jiffies - dev->trans_start);
 738         qca->net_dev->stats.tx_errors++;
 739         /* wake the queue if there is room */
 740         if (qcaspi_tx_ring_has_space(&qca->txr))
 741                 netif_wake_queue(dev);
 742 }
 743
 744 static int
 745 qcaspi_netdev_init(struct net_device *dev)
 746 {
 747         struct qcaspi *qca = netdev_priv(dev);
 748
 749         dev->mtu = QCASPI_MTU;
 750         dev->type = ARPHRD_ETHER;
 751         qca->clkspeed = qcaspi_clkspeed;
 752         qca->burst_len = qcaspi_burst_len;
 753         qca->spi_thread = NULL;
 754         qca->buffer_size = (dev->mtu + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +
 755                 QCAFRM_FOOTER_LEN + 4) * 4;
 756
 757         memset(&qca->stats, 0, sizeof(struct qcaspi_stats));
 758
 759         qca->rx_buffer = kmalloc(qca->buffer_size, GFP_KERNEL);
 760         if (!qca->rx_buffer)
 761                 return -ENOBUFS;
 762
 763         qca->rx_skb = netdev_alloc_skb(dev, qca->net_dev->mtu + VLAN_ETH_HLEN);
 764         if (!qca->rx_skb) {
 765                 kfree(qca->rx_buffer);
 766                 netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
 767                 return -ENOBUFS;
 768         }
 769
 770         return 0;
 771 }
 772
 773 static void
 774 qcaspi_netdev_uninit(struct net_device *dev)
 775 {
 776         struct qcaspi *qca = netdev_priv(dev);
 777
 778         kfree(qca->rx_buffer);
 779         qca->buffer_size = 0;
 780         if (qca->rx_skb)
 781                 dev_kfree_skb(qca->rx_skb);
 782 }
 783
 784 static int
 785 qcaspi_netdev_change_mtu(struct net_device *dev, int new_mtu)
 786 {
 787         if ((new_mtu < QCAFRM_ETHMINMTU) || (new_mtu > QCAFRM_ETHMAXMTU))
 788                 return -EINVAL;
 789
 790         dev->mtu = new_mtu;
 791
 792         return 0;
 793 }
 794
 795 static const struct net_device_ops qcaspi_netdev_ops = {
 796         .ndo_init = qcaspi_netdev_init,
 797         .ndo_uninit = qcaspi_netdev_uninit,
 798         .ndo_open = qcaspi_netdev_open,
 799         .ndo_stop = qcaspi_netdev_close,
 800         .ndo_start_xmit = qcaspi_netdev_xmit,
 801         .ndo_change_mtu = qcaspi_netdev_change_mtu,
 802         .ndo_set_mac_address = eth_mac_addr,
 803         .ndo_tx_timeout = qcaspi_netdev_tx_timeout,
 804         .ndo_validate_addr = eth_validate_addr,
 805 };
 806
 807 static void
 808 qcaspi_netdev_setup(struct net_device *dev)
 809 {
 810         struct qcaspi *qca = NULL;
 811
 812         dev->netdev_ops = &qcaspi_netdev_ops;
 813         qcaspi_set_ethtool_ops(dev);
 814         dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
 815         dev->flags = IFF_MULTICAST;
 816         dev->tx_queue_len = 100;
 817
 818         qca = netdev_priv(dev);
 819         memset(qca, 0, sizeof(struct qcaspi));
 820
 821         memset(&qca->spi_xfer1, 0, sizeof(struct spi_transfer));
 822         memset(&qca->spi_xfer2, 0, sizeof(struct spi_transfer) * 2);
 823
 824         spi_message_init(&qca->spi_msg1);
 825         spi_message_add_tail(&qca->spi_xfer1, &qca->spi_msg1);
 826
 827         spi_message_init(&qca->spi_msg2);
 828         spi_message_add_tail(&qca->spi_xfer2[0], &qca->spi_msg2);
 829         spi_message_add_tail(&qca->spi_xfer2[1], &qca->spi_msg2);
 830
 831         memset(&qca->txr, 0, sizeof(qca->txr));
 832         qca->txr.count = TX_RING_MAX_LEN;
 833 }
 834
 835 static const struct of_device_id qca_spi_of_match[] = {
 836         { .compatible = "qca,qca7000" },
 837         { /* sentinel */ }
 838 };
 839 MODULE_DEVICE_TABLE(of, qca_spi_of_match);
 840
 841 static int
 842 qca_spi_probe(struct spi_device *spi_device)
 843 {
 844         struct qcaspi *qca = NULL;
 845         struct net_device *qcaspi_devs = NULL;
 846         u8 legacy_mode = 0;
 847         u16 signature;
 848         const char *mac;
 849
 850         if (!spi_device->dev.of_node) {
 851                 dev_err(&spi_device->dev, "Missing device tree\n");
 852                 return -EINVAL;
 853         }
 854
 855         legacy_mode = of_property_read_bool(spi_device->dev.of_node,
 856                                             "qca,legacy-mode");
 857
 858         if (qcaspi_clkspeed == 0) {
 859                 if (spi_device->max_speed_hz)
 860                         qcaspi_clkspeed = spi_device->max_speed_hz;
 861                 else
 862                         qcaspi_clkspeed = QCASPI_CLK_SPEED;
 863         }
 864
 865         if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
 866             (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
 867                 dev_info(&spi_device->dev, "Invalid clkspeed: %d\n",
 868                          qcaspi_clkspeed);
 869                 return -EINVAL;
 870         }
 871
 872         if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
 873             (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
 874                 dev_info(&spi_device->dev, "Invalid burst len: %d\n",
 875                          qcaspi_burst_len);
 876                 return -EINVAL;
 877         }
 878
 879         if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
 880             (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
 881                 dev_info(&spi_device->dev, "Invalid pluggable: %d\n",
 882                          qcaspi_pluggable);
 883                 return -EINVAL;
 884         }
 885
 886         dev_info(&spi_device->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
 887                  QCASPI_DRV_VERSION,
 888                  qcaspi_clkspeed,
 889                  qcaspi_burst_len,
 890                  qcaspi_pluggable);
 891
 892         spi_device->mode = SPI_MODE_3;
 893         spi_device->max_speed_hz = qcaspi_clkspeed;
 894         if (spi_setup(spi_device) < 0) {
 895                 dev_err(&spi_device->dev, "Unable to setup SPI device\n");
 896                 return -EFAULT;
 897         }
 898
 899         qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
 900         if (!qcaspi_devs)
 901                 return -ENOMEM;
 902
 903         qcaspi_netdev_setup(qcaspi_devs);
 904
 905         qca = netdev_priv(qcaspi_devs);
 906         if (!qca) {
 907                 free_netdev(qcaspi_devs);
 908                 dev_err(&spi_device->dev, "Fail to retrieve private structure\n");
 909                 return -ENOMEM;
 910         }
 911         qca->net_dev = qcaspi_devs;
 912         qca->spi_dev = spi_device;
 913         qca->legacy_mode = legacy_mode;
 914
 915         spi_set_drvdata(spi_device, qcaspi_devs);
 916
 917         mac = of_get_mac_address(spi_device->dev.of_node);
 918
 919         if (mac)
 920                 ether_addr_copy(qca->net_dev->dev_addr, mac);
 921
 922         if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
 923                 eth_hw_addr_random(qca->net_dev);
 924                 dev_info(&spi_device->dev, "Using random MAC address: %pM\n",
 925                          qca->net_dev->dev_addr);
 926         }
 927
 928         netif_carrier_off(qca->net_dev);
 929
 930         if (!qcaspi_pluggable) {
 931                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 932                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 933
 934                 if (signature != QCASPI_GOOD_SIGNATURE) {
 935                         dev_err(&spi_device->dev, "Invalid signature (0x%04X)\n",
 936                                 signature);
 937                         free_netdev(qcaspi_devs);
 938                         return -EFAULT;
 939                 }
 940         }
 941
 942         if (register_netdev(qcaspi_devs)) {
 943                 dev_info(&spi_device->dev, "Unable to register net device %s\n",
 944                          qcaspi_devs->name);
 945                 free_netdev(qcaspi_devs);
 946                 return -EFAULT;
 947         }
 948
 949         qcaspi_init_device_debugfs(qca);
 950
 951         return 0;
 952 }
 953
 954 static int
 955 qca_spi_remove(struct spi_device *spi_device)
 956 {
 957         struct net_device *qcaspi_devs = spi_get_drvdata(spi_device);
 958         struct qcaspi *qca = netdev_priv(qcaspi_devs);
 959
 960         qcaspi_remove_device_debugfs(qca);
 961
 962         unregister_netdev(qcaspi_devs);
 963         free_netdev(qcaspi_devs);
 964
 965         return 0;
 966 }
 967
 968 static const struct spi_device_id qca_spi_id[] = {
 969         { "qca7000", 0 },
 970         { /* sentinel */ }
 971 };
 972 MODULE_DEVICE_TABLE(spi, qca_spi_id);
 973
 974 static struct spi_driver qca_spi_driver = {
 975         .driver = {
 976                 .name   = QCASPI_DRV_NAME,
 977                 .owner  = THIS_MODULE,
 978                 .of_match_table = qca_spi_of_match,
 979         },
 980         .id_table = qca_spi_id,
 981         .probe    = qca_spi_probe,
 982         .remove   = qca_spi_remove,
 983 };
 984 module_spi_driver(qca_spi_driver);
 985
 986 MODULE_DESCRIPTION("Qualcomm Atheros SPI Driver");
 987 MODULE_AUTHOR("Qualcomm Atheros Communications");
 988 MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
 989 MODULE_LICENSE("Dual BSD/GPL");
 990 MODULE_VERSION(QCASPI_DRV_VERSION);