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_7k_common.h"
  47 #include "qca_debug.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_WRITE_VERIFY_MIN 0
  73 #define QCASPI_WRITE_VERIFY_MAX 3
  74 static int wr_verify = QCASPI_WRITE_VERIFY_MIN;
  75 module_param(wr_verify, int, 0);
  76 MODULE_PARM_DESC(wr_verify, "SPI register write verify trails. Use 0-3.");
  77
  78 #define QCASPI_TX_TIMEOUT (1 * HZ)
  79 #define QCASPI_QCA7K_REBOOT_TIME_MS 1000
  80
  81 static void
  82 start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)
  83 {
  84         *intr_cause = 0;
  85
  86         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
  87         qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
  88         netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);
  89 }
  90
  91 static void
  92 end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)
  93 {
  94         u16 intr_enable = (SPI_INT_CPU_ON |
  95                            SPI_INT_PKT_AVLBL |
  96                            SPI_INT_RDBUF_ERR |
  97                            SPI_INT_WRBUF_ERR);
  98
  99         qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause, 0);
 100         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable, wr_verify);
 101         netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);
 102 }
 103
 104 static u32
 105 qcaspi_write_burst(struct qcaspi *qca, u8 *src, u32 len)
 106 {
 107         __be16 cmd;
 108         struct spi_message msg;
 109         struct spi_transfer transfer[2];
 110         int ret;
 111
 112         memset(&transfer, 0, sizeof(transfer));
 113         spi_message_init(&msg);
 114
 115         cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 116         transfer[0].tx_buf = &cmd;
 117         transfer[0].len = QCASPI_CMD_LEN;
 118         transfer[1].tx_buf = src;
 119         transfer[1].len = len;
 120
 121         spi_message_add_tail(&transfer[0], &msg);
 122         spi_message_add_tail(&transfer[1], &msg);
 123         ret = spi_sync(qca->spi_dev, &msg);
 124
 125         if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {
 126                 qcaspi_spi_error(qca);
 127                 return 0;
 128         }
 129
 130         return len;
 131 }
 132
 133 static u32
 134 qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)
 135 {
 136         struct spi_message msg;
 137         struct spi_transfer transfer;
 138         int ret;
 139
 140         memset(&transfer, 0, sizeof(transfer));
 141         spi_message_init(&msg);
 142
 143         transfer.tx_buf = src;
 144         transfer.len = len;
 145
 146         spi_message_add_tail(&transfer, &msg);
 147         ret = spi_sync(qca->spi_dev, &msg);
 148
 149         if (ret || (msg.actual_length != len)) {
 150                 qcaspi_spi_error(qca);
 151                 return 0;
 152         }
 153
 154         return len;
 155 }
 156
 157 static u32
 158 qcaspi_read_burst(struct qcaspi *qca, u8 *dst, u32 len)
 159 {
 160         struct spi_message msg;
 161         __be16 cmd;
 162         struct spi_transfer transfer[2];
 163         int ret;
 164
 165         memset(&transfer, 0, sizeof(transfer));
 166         spi_message_init(&msg);
 167
 168         cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 169         transfer[0].tx_buf = &cmd;
 170         transfer[0].len = QCASPI_CMD_LEN;
 171         transfer[1].rx_buf = dst;
 172         transfer[1].len = len;
 173
 174         spi_message_add_tail(&transfer[0], &msg);
 175         spi_message_add_tail(&transfer[1], &msg);
 176         ret = spi_sync(qca->spi_dev, &msg);
 177
 178         if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {
 179                 qcaspi_spi_error(qca);
 180                 return 0;
 181         }
 182
 183         return len;
 184 }
 185
 186 static u32
 187 qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)
 188 {
 189         struct spi_message msg;
 190         struct spi_transfer transfer;
 191         int ret;
 192
 193         memset(&transfer, 0, sizeof(transfer));
 194         spi_message_init(&msg);
 195
 196         transfer.rx_buf = dst;
 197         transfer.len = len;
 198
 199         spi_message_add_tail(&transfer, &msg);
 200         ret = spi_sync(qca->spi_dev, &msg);
 201
 202         if (ret || (msg.actual_length != len)) {
 203                 qcaspi_spi_error(qca);
 204                 return 0;
 205         }
 206
 207         return len;
 208 }
 209
 210 static int
 211 qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd)
 212 {
 213         __be16 tx_data;
 214         struct spi_message msg;
 215         struct spi_transfer transfer;
 216         int ret;
 217
 218         memset(&transfer, 0, sizeof(transfer));
 219
 220         spi_message_init(&msg);
 221
 222         tx_data = cpu_to_be16(cmd);
 223         transfer.len = sizeof(cmd);
 224         transfer.tx_buf = &tx_data;
 225         spi_message_add_tail(&transfer, &msg);
 226
 227         ret = spi_sync(qca->spi_dev, &msg);
 228
 229         if (!ret)
 230                 ret = msg.status;
 231
 232         if (ret)
 233                 qcaspi_spi_error(qca);
 234
 235         return ret;
 236 }
 237
 238 static int
 239 qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
 240 {
 241         u32 count;
 242         u32 written;
 243         u32 offset;
 244         u32 len;
 245
 246         len = skb->len;
 247
 248         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len, wr_verify);
 249         if (qca->legacy_mode)
 250                 qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 251
 252         offset = 0;
 253         while (len) {
 254                 count = len;
 255                 if (count > qca->burst_len)
 256                         count = qca->burst_len;
 257
 258                 if (qca->legacy_mode) {
 259                         written = qcaspi_write_legacy(qca,
 260                                                       skb->data + offset,
 261                                                       count);
 262                 } else {
 263                         written = qcaspi_write_burst(qca,
 264                                                      skb->data + offset,
 265                                                      count);
 266                 }
 267
 268                 if (written != count)
 269                         return -1;
 270
 271                 offset += count;
 272                 len -= count;
 273         }
 274
 275         return 0;
 276 }
 277
 278 static int
 279 qcaspi_transmit(struct qcaspi *qca)
 280 {
 281         struct net_device_stats *n_stats = &qca->net_dev->stats;
 282         u16 available = 0;
 283         u32 pkt_len;
 284         u16 new_head;
 285         u16 packets = 0;
 286
 287         if (qca->txr.skb[qca->txr.head] == NULL)
 288                 return 0;
 289
 290         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, &available);
 291
 292         if (available > QCASPI_HW_BUF_LEN) {
 293                 /* This could only happen by interferences on the SPI line.
 294                  * So retry later ...
 295                  */
 296                 qca->stats.buf_avail_err++;
 297                 return -1;
 298         }
 299
 300         while (qca->txr.skb[qca->txr.head]) {
 301                 pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;
 302
 303                 if (available < pkt_len) {
 304                         if (packets == 0)
 305                                 qca->stats.write_buf_miss++;
 306                         break;
 307                 }
 308
 309                 if (qcaspi_tx_frame(qca, qca->txr.skb[qca->txr.head]) == -1) {
 310                         qca->stats.write_err++;
 311                         return -1;
 312                 }
 313
 314                 packets++;
 315                 n_stats->tx_packets++;
 316                 n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;
 317                 available -= pkt_len;
 318
 319                 /* remove the skb from the queue */
 320                 /* XXX After inconsistent lock states netif_tx_lock()
 321                  * has been replaced by netif_tx_lock_bh() and so on.
 322                  */
 323                 netif_tx_lock_bh(qca->net_dev);
 324                 dev_kfree_skb(qca->txr.skb[qca->txr.head]);
 325                 qca->txr.skb[qca->txr.head] = NULL;
 326                 qca->txr.size -= pkt_len;
 327                 new_head = qca->txr.head + 1;
 328                 if (new_head >= qca->txr.count)
 329                         new_head = 0;
 330                 qca->txr.head = new_head;
 331                 if (netif_queue_stopped(qca->net_dev))
 332                         netif_wake_queue(qca->net_dev);
 333                 netif_tx_unlock_bh(qca->net_dev);
 334         }
 335
 336         return 0;
 337 }
 338
 339 static int
 340 qcaspi_receive(struct qcaspi *qca)
 341 {
 342         struct net_device *net_dev = qca->net_dev;
 343         struct net_device_stats *n_stats = &net_dev->stats;
 344         u16 available = 0;
 345         u32 bytes_read;
 346         u8 *cp;
 347
 348         /* Allocate rx SKB if we don't have one available. */
 349         if (!qca->rx_skb) {
 350                 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
 351                                                         net_dev->mtu +
 352                                                         VLAN_ETH_HLEN);
 353                 if (!qca->rx_skb) {
 354                         netdev_dbg(net_dev, "out of RX resources\n");
 355                         qca->stats.out_of_mem++;
 356                         return -1;
 357                 }
 358         }
 359
 360         /* Read the packet size. */
 361         qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);
 362
 363         netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %08x\n",
 364                    available);
 365
 366         if (available > QCASPI_HW_BUF_LEN + QCASPI_HW_PKT_LEN) {
 367                 /* This could only happen by interferences on the SPI line.
 368                  * So retry later ...
 369                  */
 370                 qca->stats.buf_avail_err++;
 371                 return -1;
 372         } else if (available == 0) {
 373                 netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");
 374                 return -1;
 375         }
 376
 377         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available, wr_verify);
 378
 379         if (qca->legacy_mode)
 380                 qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 381
 382         while (available) {
 383                 u32 count = available;
 384
 385                 if (count > qca->burst_len)
 386                         count = qca->burst_len;
 387
 388                 if (qca->legacy_mode) {
 389                         bytes_read = qcaspi_read_legacy(qca, qca->rx_buffer,
 390                                                         count);
 391                 } else {
 392                         bytes_read = qcaspi_read_burst(qca, qca->rx_buffer,
 393                                                        count);
 394                 }
 395
 396                 netdev_dbg(net_dev, "available: %d, byte read: %d\n",
 397                            available, bytes_read);
 398
 399                 if (bytes_read) {
 400                         available -= bytes_read;
 401                 } else {
 402                         qca->stats.read_err++;
 403                         return -1;
 404                 }
 405
 406                 cp = qca->rx_buffer;
 407
 408                 while ((bytes_read--) && (qca->rx_skb)) {
 409                         s32 retcode;
 410
 411                         retcode = qcafrm_fsm_decode(&qca->frm_handle,
 412                                                     qca->rx_skb->data,
 413                                                     skb_tailroom(qca->rx_skb),
 414                                                     *cp);
 415                         cp++;
 416                         switch (retcode) {
 417                         case QCAFRM_GATHER:
 418                         case QCAFRM_NOHEAD:
 419                                 break;
 420                         case QCAFRM_NOTAIL:
 421                                 netdev_dbg(net_dev, "no RX tail\n");
 422                                 n_stats->rx_errors++;
 423                                 n_stats->rx_dropped++;
 424                                 break;
 425                         case QCAFRM_INVLEN:
 426                                 netdev_dbg(net_dev, "invalid RX length\n");
 427                                 n_stats->rx_errors++;
 428                                 n_stats->rx_dropped++;
 429                                 break;
 430                         default:
 431                                 qca->rx_skb->dev = qca->net_dev;
 432                                 n_stats->rx_packets++;
 433                                 n_stats->rx_bytes += retcode;
 434                                 skb_put(qca->rx_skb, retcode);
 435                                 qca->rx_skb->protocol = eth_type_trans(
 436                                         qca->rx_skb, qca->rx_skb->dev);
 437                                 qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
 438                                 netif_rx_ni(qca->rx_skb);
 439                                 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
 440                                         net_dev->mtu + VLAN_ETH_HLEN);
 441                                 if (!qca->rx_skb) {
 442                                         netdev_dbg(net_dev, "out of RX resources\n");
 443                                         n_stats->rx_errors++;
 444                                         qca->stats.out_of_mem++;
 445                                         break;
 446                                 }
 447                         }
 448                 }
 449         }
 450
 451         return 0;
 452 }
 453
 454 /*   Check that tx ring stores only so much bytes
 455  *   that fit into the internal QCA buffer.
 456  */
 457
 458 static int
 459 qcaspi_tx_ring_has_space(struct tx_ring *txr)
 460 {
 461         if (txr->skb[txr->tail])
 462                 return 0;
 463
 464         return (txr->size + QCAFRM_MAX_LEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
 465 }
 466
 467 /*   Flush the tx ring. This function is only safe to
 468  *   call from the qcaspi_spi_thread.
 469  */
 470
 471 static void
 472 qcaspi_flush_tx_ring(struct qcaspi *qca)
 473 {
 474         int i;
 475
 476         /* XXX After inconsistent lock states netif_tx_lock()
 477          * has been replaced by netif_tx_lock_bh() and so on.
 478          */
 479         netif_tx_lock_bh(qca->net_dev);
 480         for (i = 0; i < TX_RING_MAX_LEN; i++) {
 481                 if (qca->txr.skb[i]) {
 482                         dev_kfree_skb(qca->txr.skb[i]);
 483                         qca->txr.skb[i] = NULL;
 484                         qca->net_dev->stats.tx_dropped++;
 485                 }
 486         }
 487         qca->txr.tail = 0;
 488         qca->txr.head = 0;
 489         qca->txr.size = 0;
 490         netif_tx_unlock_bh(qca->net_dev);
 491 }
 492
 493 static void
 494 qcaspi_qca7k_sync(struct qcaspi *qca, int event)
 495 {
 496         u16 signature = 0;
 497         u16 spi_config;
 498         u16 wrbuf_space = 0;
 499
 500         if (event == QCASPI_EVENT_CPUON) {
 501                 /* Read signature twice, if not valid
 502                  * go back to unknown state.
 503                  */
 504                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 505                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 506                 if (signature != QCASPI_GOOD_SIGNATURE) {
 507                         qca->sync = QCASPI_SYNC_UNKNOWN;
 508                         netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");
 509                         return;
 510                 } else {
 511                         /* ensure that the WRBUF is empty */
 512                         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,
 513                                              &wrbuf_space);
 514                         if (wrbuf_space != QCASPI_HW_BUF_LEN) {
 515                                 netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");
 516                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 517                         } else {
 518                                 netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");
 519                                 qca->sync = QCASPI_SYNC_READY;
 520                                 return;
 521                         }
 522                 }
 523         }
 524
 525         switch (qca->sync) {
 526         case QCASPI_SYNC_READY:
 527                 /* Check signature twice, if not valid go to unknown state. */
 528                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 529                 if (signature != QCASPI_GOOD_SIGNATURE)
 530                         qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 531
 532                 if (signature != QCASPI_GOOD_SIGNATURE) {
 533                         qca->sync = QCASPI_SYNC_UNKNOWN;
 534                         netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");
 535                         /* don't reset right away */
 536                         return;
 537                 }
 538                 break;
 539         case QCASPI_SYNC_UNKNOWN:
 540                 /* Read signature, if not valid stay in unknown state */
 541                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 542                 if (signature != QCASPI_GOOD_SIGNATURE) {
 543                         netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");
 544                         return;
 545                 }
 546
 547                 /* TODO: use GPIO to reset QCA7000 in legacy mode*/
 548                 netdev_dbg(qca->net_dev, "sync: resetting device.\n");
 549                 qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);
 550                 spi_config |= QCASPI_SLAVE_RESET_BIT;
 551                 qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config, 0);
 552
 553                 qca->sync = QCASPI_SYNC_RESET;
 554                 qca->stats.trig_reset++;
 555                 qca->reset_count = 0;
 556                 break;
 557         case QCASPI_SYNC_RESET:
 558                 qca->reset_count++;
 559                 netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",
 560                            qca->reset_count);
 561                 if (qca->reset_count >= QCASPI_RESET_TIMEOUT) {
 562                         /* reset did not seem to take place, try again */
 563                         qca->sync = QCASPI_SYNC_UNKNOWN;
 564                         qca->stats.reset_timeout++;
 565                         netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");
 566                 }
 567                 break;
 568         }
 569 }
 570
 571 static int
 572 qcaspi_spi_thread(void *data)
 573 {
 574         struct qcaspi *qca = data;
 575         u16 intr_cause = 0;
 576
 577         netdev_info(qca->net_dev, "SPI thread created\n");
 578         while (!kthread_should_stop()) {
 579                 set_current_state(TASK_INTERRUPTIBLE);
 580                 if ((qca->intr_req == qca->intr_svc) &&
 581                     (qca->txr.skb[qca->txr.head] == NULL) &&
 582                     (qca->sync == QCASPI_SYNC_READY))
 583                         schedule();
 584
 585                 set_current_state(TASK_RUNNING);
 586
 587                 netdev_dbg(qca->net_dev, "have work to do. int: %d, tx_skb: %p\n",
 588                            qca->intr_req - qca->intr_svc,
 589                            qca->txr.skb[qca->txr.head]);
 590
 591                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
 592
 593                 if (qca->sync != QCASPI_SYNC_READY) {
 594                         netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",
 595                                    (unsigned int)qca->sync);
 596                         netif_stop_queue(qca->net_dev);
 597                         netif_carrier_off(qca->net_dev);
 598                         qcaspi_flush_tx_ring(qca);
 599                         msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
 600                 }
 601
 602                 if (qca->intr_svc != qca->intr_req) {
 603                         qca->intr_svc = qca->intr_req;
 604                         start_spi_intr_handling(qca, &intr_cause);
 605
 606                         if (intr_cause & SPI_INT_CPU_ON) {
 607                                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);
 608
 609                                 /* not synced. */
 610                                 if (qca->sync != QCASPI_SYNC_READY)
 611                                         continue;
 612
 613                                 qca->stats.device_reset++;
 614                                 netif_wake_queue(qca->net_dev);
 615                                 netif_carrier_on(qca->net_dev);
 616                         }
 617
 618                         if (intr_cause & SPI_INT_RDBUF_ERR) {
 619                                 /* restart sync */
 620                                 netdev_dbg(qca->net_dev, "===> rdbuf error!\n");
 621                                 qca->stats.read_buf_err++;
 622                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 623                                 continue;
 624                         }
 625
 626                         if (intr_cause & SPI_INT_WRBUF_ERR) {
 627                                 /* restart sync */
 628                                 netdev_dbg(qca->net_dev, "===> wrbuf error!\n");
 629                                 qca->stats.write_buf_err++;
 630                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 631                                 continue;
 632                         }
 633
 634                         /* can only handle other interrupts
 635                          * if sync has occurred
 636                          */
 637                         if (qca->sync == QCASPI_SYNC_READY) {
 638                                 if (intr_cause & SPI_INT_PKT_AVLBL)
 639                                         qcaspi_receive(qca);
 640                         }
 641
 642                         end_spi_intr_handling(qca, intr_cause);
 643                 }
 644
 645                 if (qca->sync == QCASPI_SYNC_READY)
 646                         qcaspi_transmit(qca);
 647         }
 648         set_current_state(TASK_RUNNING);
 649         netdev_info(qca->net_dev, "SPI thread exit\n");
 650
 651         return 0;
 652 }
 653
 654 static irqreturn_t
 655 qcaspi_intr_handler(int irq, void *data)
 656 {
 657         struct qcaspi *qca = data;
 658
 659         qca->intr_req++;
 660         if (qca->spi_thread &&
 661             qca->spi_thread->state != TASK_RUNNING)
 662                 wake_up_process(qca->spi_thread);
 663
 664         return IRQ_HANDLED;
 665 }
 666
 667 static int
 668 qcaspi_netdev_open(struct net_device *dev)
 669 {
 670         struct qcaspi *qca = netdev_priv(dev);
 671         int ret = 0;
 672
 673         if (!qca)
 674                 return -EINVAL;
 675
 676         qca->intr_req = 1;
 677         qca->intr_svc = 0;
 678         qca->sync = QCASPI_SYNC_UNKNOWN;
 679         qcafrm_fsm_init_spi(&qca->frm_handle);
 680
 681         qca->spi_thread = kthread_run((void *)qcaspi_spi_thread,
 682                                       qca, "%s", dev->name);
 683
 684         if (IS_ERR(qca->spi_thread)) {
 685                 netdev_err(dev, "%s: unable to start kernel thread.\n",
 686                            QCASPI_DRV_NAME);
 687                 return PTR_ERR(qca->spi_thread);
 688         }
 689
 690         ret = request_irq(qca->spi_dev->irq, qcaspi_intr_handler, 0,
 691                           dev->name, qca);
 692         if (ret) {
 693                 netdev_err(dev, "%s: unable to get IRQ %d (irqval=%d).\n",
 694                            QCASPI_DRV_NAME, qca->spi_dev->irq, ret);
 695                 kthread_stop(qca->spi_thread);
 696                 return ret;
 697         }
 698
 699         /* SPI thread takes care of TX queue */
 700
 701         return 0;
 702 }
 703
 704 static int
 705 qcaspi_netdev_close(struct net_device *dev)
 706 {
 707         struct qcaspi *qca = netdev_priv(dev);
 708
 709         netif_stop_queue(dev);
 710
 711         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
 712         free_irq(qca->spi_dev->irq, qca);
 713
 714         kthread_stop(qca->spi_thread);
 715         qca->spi_thread = NULL;
 716         qcaspi_flush_tx_ring(qca);
 717
 718         return 0;
 719 }
 720
 721 static netdev_tx_t
 722 qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
 723 {
 724         u32 frame_len;
 725         u8 *ptmp;
 726         struct qcaspi *qca = netdev_priv(dev);
 727         u16 new_tail;
 728         struct sk_buff *tskb;
 729         u8 pad_len = 0;
 730
 731         if (skb->len < QCAFRM_MIN_LEN)
 732                 pad_len = QCAFRM_MIN_LEN - skb->len;
 733
 734         if (qca->txr.skb[qca->txr.tail]) {
 735                 netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");
 736                 netif_stop_queue(qca->net_dev);
 737                 qca->stats.ring_full++;
 738                 return NETDEV_TX_BUSY;
 739         }
 740
 741         if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||
 742             (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {
 743                 tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,
 744                                        QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);
 745                 if (!tskb) {
 746                         qca->stats.out_of_mem++;
 747                         return NETDEV_TX_BUSY;
 748                 }
 749                 dev_kfree_skb(skb);
 750                 skb = tskb;
 751         }
 752
 753         frame_len = skb->len + pad_len;
 754
 755         ptmp = skb_push(skb, QCAFRM_HEADER_LEN);
 756         qcafrm_create_header(ptmp, frame_len);
 757
 758         if (pad_len) {
 759                 ptmp = skb_put_zero(skb, pad_len);
 760         }
 761
 762         ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);
 763         qcafrm_create_footer(ptmp);
 764
 765         netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",
 766                    skb->len);
 767
 768         qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;
 769
 770         new_tail = qca->txr.tail + 1;
 771         if (new_tail >= qca->txr.count)
 772                 new_tail = 0;
 773
 774         qca->txr.skb[qca->txr.tail] = skb;
 775         qca->txr.tail = new_tail;
 776
 777         if (!qcaspi_tx_ring_has_space(&qca->txr)) {
 778                 netif_stop_queue(qca->net_dev);
 779                 qca->stats.ring_full++;
 780         }
 781
 782         netif_trans_update(dev);
 783
 784         if (qca->spi_thread &&
 785             qca->spi_thread->state != TASK_RUNNING)
 786                 wake_up_process(qca->spi_thread);
 787
 788         return NETDEV_TX_OK;
 789 }
 790
 791 static void
 792 qcaspi_netdev_tx_timeout(struct net_device *dev, unsigned int txqueue)
 793 {
 794         struct qcaspi *qca = netdev_priv(dev);
 795
 796         netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
 797                     jiffies, jiffies - dev_trans_start(dev));
 798         qca->net_dev->stats.tx_errors++;
 799         /* Trigger tx queue flush and QCA7000 reset */
 800         qca->sync = QCASPI_SYNC_UNKNOWN;
 801
 802         if (qca->spi_thread)
 803                 wake_up_process(qca->spi_thread);
 804 }
 805
 806 static int
 807 qcaspi_netdev_init(struct net_device *dev)
 808 {
 809         struct qcaspi *qca = netdev_priv(dev);
 810
 811         dev->mtu = QCAFRM_MAX_MTU;
 812         dev->type = ARPHRD_ETHER;
 813         qca->clkspeed = qcaspi_clkspeed;
 814         qca->burst_len = qcaspi_burst_len;
 815         qca->spi_thread = NULL;
 816         qca->buffer_size = (dev->mtu + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +
 817                 QCAFRM_FOOTER_LEN + 4) * 4;
 818
 819         memset(&qca->stats, 0, sizeof(struct qcaspi_stats));
 820
 821         qca->rx_buffer = kmalloc(qca->buffer_size, GFP_KERNEL);
 822         if (!qca->rx_buffer)
 823                 return -ENOBUFS;
 824
 825         qca->rx_skb = netdev_alloc_skb_ip_align(dev, qca->net_dev->mtu +
 826                                                 VLAN_ETH_HLEN);
 827         if (!qca->rx_skb) {
 828                 kfree(qca->rx_buffer);
 829                 netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
 830                 return -ENOBUFS;
 831         }
 832
 833         return 0;
 834 }
 835
 836 static void
 837 qcaspi_netdev_uninit(struct net_device *dev)
 838 {
 839         struct qcaspi *qca = netdev_priv(dev);
 840
 841         kfree(qca->rx_buffer);
 842         qca->buffer_size = 0;
 843         dev_kfree_skb(qca->rx_skb);
 844 }
 845
 846 static const struct net_device_ops qcaspi_netdev_ops = {
 847         .ndo_init = qcaspi_netdev_init,
 848         .ndo_uninit = qcaspi_netdev_uninit,
 849         .ndo_open = qcaspi_netdev_open,
 850         .ndo_stop = qcaspi_netdev_close,
 851         .ndo_start_xmit = qcaspi_netdev_xmit,
 852         .ndo_set_mac_address = eth_mac_addr,
 853         .ndo_tx_timeout = qcaspi_netdev_tx_timeout,
 854         .ndo_validate_addr = eth_validate_addr,
 855 };
 856
 857 static void
 858 qcaspi_netdev_setup(struct net_device *dev)
 859 {
 860         struct qcaspi *qca = NULL;
 861
 862         dev->netdev_ops = &qcaspi_netdev_ops;
 863         qcaspi_set_ethtool_ops(dev);
 864         dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
 865         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 866         dev->tx_queue_len = 100;
 867
 868         /* MTU range: 46 - 1500 */
 869         dev->min_mtu = QCAFRM_MIN_MTU;
 870         dev->max_mtu = QCAFRM_MAX_MTU;
 871
 872         qca = netdev_priv(dev);
 873         memset(qca, 0, sizeof(struct qcaspi));
 874
 875         memset(&qca->txr, 0, sizeof(qca->txr));
 876         qca->txr.count = TX_RING_MAX_LEN;
 877 }
 878
 879 static const struct of_device_id qca_spi_of_match[] = {
 880         { .compatible = "qca,qca7000" },
 881         { /* sentinel */ }
 882 };
 883 MODULE_DEVICE_TABLE(of, qca_spi_of_match);
 884
 885 static int
 886 qca_spi_probe(struct spi_device *spi)
 887 {
 888         struct qcaspi *qca = NULL;
 889         struct net_device *qcaspi_devs = NULL;
 890         u8 legacy_mode = 0;
 891         u16 signature;
 892         int ret;
 893
 894         if (!spi->dev.of_node) {
 895                 dev_err(&spi->dev, "Missing device tree\n");
 896                 return -EINVAL;
 897         }
 898
 899         legacy_mode = of_property_read_bool(spi->dev.of_node,
 900                                             "qca,legacy-mode");
 901
 902         if (qcaspi_clkspeed == 0) {
 903                 if (spi->max_speed_hz)
 904                         qcaspi_clkspeed = spi->max_speed_hz;
 905                 else
 906                         qcaspi_clkspeed = QCASPI_CLK_SPEED;
 907         }
 908
 909         if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
 910             (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
 911                 dev_err(&spi->dev, "Invalid clkspeed: %d\n",
 912                         qcaspi_clkspeed);
 913                 return -EINVAL;
 914         }
 915
 916         if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
 917             (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
 918                 dev_err(&spi->dev, "Invalid burst len: %d\n",
 919                         qcaspi_burst_len);
 920                 return -EINVAL;
 921         }
 922
 923         if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
 924             (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
 925                 dev_err(&spi->dev, "Invalid pluggable: %d\n",
 926                         qcaspi_pluggable);
 927                 return -EINVAL;
 928         }
 929
 930         if (wr_verify < QCASPI_WRITE_VERIFY_MIN ||
 931             wr_verify > QCASPI_WRITE_VERIFY_MAX) {
 932                 dev_err(&spi->dev, "Invalid write verify: %d\n",
 933                         wr_verify);
 934                 return -EINVAL;
 935         }
 936
 937         dev_info(&spi->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
 938                  QCASPI_DRV_VERSION,
 939                  qcaspi_clkspeed,
 940                  qcaspi_burst_len,
 941                  qcaspi_pluggable);
 942
 943         spi->mode = SPI_MODE_3;
 944         spi->max_speed_hz = qcaspi_clkspeed;
 945         if (spi_setup(spi) < 0) {
 946                 dev_err(&spi->dev, "Unable to setup SPI device\n");
 947                 return -EFAULT;
 948         }
 949
 950         qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
 951         if (!qcaspi_devs)
 952                 return -ENOMEM;
 953
 954         qcaspi_netdev_setup(qcaspi_devs);
 955         SET_NETDEV_DEV(qcaspi_devs, &spi->dev);
 956
 957         qca = netdev_priv(qcaspi_devs);
 958         if (!qca) {
 959                 free_netdev(qcaspi_devs);
 960                 dev_err(&spi->dev, "Fail to retrieve private structure\n");
 961                 return -ENOMEM;
 962         }
 963         qca->net_dev = qcaspi_devs;
 964         qca->spi_dev = spi;
 965         qca->legacy_mode = legacy_mode;
 966
 967         spi_set_drvdata(spi, qcaspi_devs);
 968
 969         ret = of_get_mac_address(spi->dev.of_node, qca->net_dev->dev_addr);
 970         if (ret) {
 971                 eth_hw_addr_random(qca->net_dev);
 972                 dev_info(&spi->dev, "Using random MAC address: %pM\n",
 973                          qca->net_dev->dev_addr);
 974         }
 975
 976         netif_carrier_off(qca->net_dev);
 977
 978         if (!qcaspi_pluggable) {
 979                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 980                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 981
 982                 if (signature != QCASPI_GOOD_SIGNATURE) {
 983                         dev_err(&spi->dev, "Invalid signature (0x%04X)\n",
 984                                 signature);
 985                         free_netdev(qcaspi_devs);
 986                         return -EFAULT;
 987                 }
 988         }
 989
 990         if (register_netdev(qcaspi_devs)) {
 991                 dev_err(&spi->dev, "Unable to register net device %s\n",
 992                         qcaspi_devs->name);
 993                 free_netdev(qcaspi_devs);
 994                 return -EFAULT;
 995         }
 996
 997         qcaspi_init_device_debugfs(qca);
 998
 999         return 0;
1000 }
1001
1002 static int
1003 qca_spi_remove(struct spi_device *spi)
1004 {
1005         struct net_device *qcaspi_devs = spi_get_drvdata(spi);
1006         struct qcaspi *qca = netdev_priv(qcaspi_devs);
1007
1008         qcaspi_remove_device_debugfs(qca);
1009
1010         unregister_netdev(qcaspi_devs);
1011         free_netdev(qcaspi_devs);
1012
1013         return 0;
1014 }
1015
1016 static const struct spi_device_id qca_spi_id[] = {
1017         { "qca7000", 0 },
1018         { /* sentinel */ }
1019 };
1020 MODULE_DEVICE_TABLE(spi, qca_spi_id);
1021
1022 static struct spi_driver qca_spi_driver = {
1023         .driver = {
1024                 .name   = QCASPI_DRV_NAME,
1025                 .of_match_table = qca_spi_of_match,
1026         },
1027         .id_table = qca_spi_id,
1028         .probe    = qca_spi_probe,
1029         .remove   = qca_spi_remove,
1030 };
1031 module_spi_driver(qca_spi_driver);
1032
1033 MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 SPI Driver");
1034 MODULE_AUTHOR("Qualcomm Atheros Communications");
1035 MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
1036 MODULE_LICENSE("Dual BSD/GPL");
1037 MODULE_VERSION(QCASPI_DRV_VERSION);