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_ip_align(net_dev,
 300                                                         net_dev->mtu +
 301                                                         VLAN_ETH_HLEN);
 302                 if (!qca->rx_skb) {
 303                         netdev_dbg(net_dev, "out of RX resources\n");
 304                         qca->stats.out_of_mem++;
 305                         return -1;
 306                 }
 307         }
 308
 309         /* Read the packet size. */
 310         qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);
 311         netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %08x\n",
 312                    available);
 313
 314         if (available == 0) {
 315                 netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");
 316                 return -1;
 317         }
 318
 319         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available);
 320
 321         if (qca->legacy_mode)
 322                 qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 323
 324         while (available) {
 325                 u32 count = available;
 326
 327                 if (count > qca->burst_len)
 328                         count = qca->burst_len;
 329
 330                 if (qca->legacy_mode) {
 331                         bytes_read = qcaspi_read_legacy(qca, qca->rx_buffer,
 332                                                         count);
 333                 } else {
 334                         bytes_read = qcaspi_read_burst(qca, qca->rx_buffer,
 335                                                        count);
 336                 }
 337
 338                 netdev_dbg(net_dev, "available: %d, byte read: %d\n",
 339                            available, bytes_read);
 340
 341                 if (bytes_read) {
 342                         available -= bytes_read;
 343                 } else {
 344                         qca->stats.read_err++;
 345                         return -1;
 346                 }
 347
 348                 cp = qca->rx_buffer;
 349
 350                 while ((bytes_read--) && (qca->rx_skb)) {
 351                         s32 retcode;
 352
 353                         retcode = qcafrm_fsm_decode(&qca->frm_handle,
 354                                                     qca->rx_skb->data,
 355                                                     skb_tailroom(qca->rx_skb),
 356                                                     *cp);
 357                         cp++;
 358                         switch (retcode) {
 359                         case QCAFRM_GATHER:
 360                         case QCAFRM_NOHEAD:
 361                                 break;
 362                         case QCAFRM_NOTAIL:
 363                                 netdev_dbg(net_dev, "no RX tail\n");
 364                                 n_stats->rx_errors++;
 365                                 n_stats->rx_dropped++;
 366                                 break;
 367                         case QCAFRM_INVLEN:
 368                                 netdev_dbg(net_dev, "invalid RX length\n");
 369                                 n_stats->rx_errors++;
 370                                 n_stats->rx_dropped++;
 371                                 break;
 372                         default:
 373                                 qca->rx_skb->dev = qca->net_dev;
 374                                 n_stats->rx_packets++;
 375                                 n_stats->rx_bytes += retcode;
 376                                 skb_put(qca->rx_skb, retcode);
 377                                 qca->rx_skb->protocol = eth_type_trans(
 378                                         qca->rx_skb, qca->rx_skb->dev);
 379                                 qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
 380                                 netif_rx_ni(qca->rx_skb);
 381                                 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
 382                                         net_dev->mtu + VLAN_ETH_HLEN);
 383                                 if (!qca->rx_skb) {
 384                                         netdev_dbg(net_dev, "out of RX resources\n");
 385                                         n_stats->rx_errors++;
 386                                         qca->stats.out_of_mem++;
 387                                         break;
 388                                 }
 389                         }
 390                 }
 391         }
 392
 393         return 0;
 394 }
 395
 396 /*   Check that tx ring stores only so much bytes
 397  *   that fit into the internal QCA buffer.
 398  */
 399
 400 static int
 401 qcaspi_tx_ring_has_space(struct tx_ring *txr)
 402 {
 403         if (txr->skb[txr->tail])
 404                 return 0;
 405
 406         return (txr->size + QCAFRM_ETHMAXLEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
 407 }
 408
 409 /*   Flush the tx ring. This function is only safe to
 410  *   call from the qcaspi_spi_thread.
 411  */
 412
 413 static void
 414 qcaspi_flush_tx_ring(struct qcaspi *qca)
 415 {
 416         int i;
 417
 418         /* XXX After inconsistent lock states netif_tx_lock()
 419          * has been replaced by netif_tx_lock_bh() and so on.
 420          */
 421         netif_tx_lock_bh(qca->net_dev);
 422         for (i = 0; i < TX_RING_MAX_LEN; i++) {
 423                 if (qca->txr.skb[i]) {
 424                         dev_kfree_skb(qca->txr.skb[i]);
 425                         qca->txr.skb[i] = NULL;
 426                         qca->net_dev->stats.tx_dropped++;
 427                 }
 428         }
 429         qca->txr.tail = 0;
 430         qca->txr.head = 0;
 431         qca->txr.size = 0;
 432         netif_tx_unlock_bh(qca->net_dev);
 433 }
 434
 435 static void
 436 qcaspi_qca7k_sync(struct qcaspi *qca, int event)
 437 {
 438         u16 signature = 0;
 439         u16 spi_config;
 440         u16 wrbuf_space = 0;
 441         static u16 reset_count;
 442
 443         if (event == QCASPI_EVENT_CPUON) {
 444                 /* Read signature twice, if not valid
 445                  * go back to unknown state.
 446                  */
 447                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 448                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 449                 if (signature != QCASPI_GOOD_SIGNATURE) {
 450                         qca->sync = QCASPI_SYNC_UNKNOWN;
 451                         netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");
 452                 } else {
 453                         /* ensure that the WRBUF is empty */
 454                         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,
 455                                              &wrbuf_space);
 456                         if (wrbuf_space != QCASPI_HW_BUF_LEN) {
 457                                 netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");
 458                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 459                         } else {
 460                                 netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");
 461                                 qca->sync = QCASPI_SYNC_READY;
 462                                 return;
 463                         }
 464                 }
 465         }
 466
 467         switch (qca->sync) {
 468         case QCASPI_SYNC_READY:
 469                 /* Read signature, if not valid go to unknown state. */
 470                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 471                 if (signature != QCASPI_GOOD_SIGNATURE) {
 472                         qca->sync = QCASPI_SYNC_UNKNOWN;
 473                         netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");
 474                         /* don't reset right away */
 475                         return;
 476                 }
 477                 break;
 478         case QCASPI_SYNC_UNKNOWN:
 479                 /* Read signature, if not valid stay in unknown state */
 480                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 481                 if (signature != QCASPI_GOOD_SIGNATURE) {
 482                         netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");
 483                         return;
 484                 }
 485
 486                 /* TODO: use GPIO to reset QCA7000 in legacy mode*/
 487                 netdev_dbg(qca->net_dev, "sync: resetting device.\n");
 488                 qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);
 489                 spi_config |= QCASPI_SLAVE_RESET_BIT;
 490                 qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config);
 491
 492                 qca->sync = QCASPI_SYNC_RESET;
 493                 qca->stats.trig_reset++;
 494                 reset_count = 0;
 495                 break;
 496         case QCASPI_SYNC_RESET:
 497                 reset_count++;
 498                 netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",
 499                            reset_count);
 500                 if (reset_count >= QCASPI_RESET_TIMEOUT) {
 501                         /* reset did not seem to take place, try again */
 502                         qca->sync = QCASPI_SYNC_UNKNOWN;
 503                         qca->stats.reset_timeout++;
 504                         netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");
 505                 }
 506                 break;
 507         }
 508 }
 509
 510 static int
 511 qcaspi_spi_thread(void *data)
 512 {
 513         struct qcaspi *qca = data;
 514         u16 intr_cause = 0;
 515
 516         netdev_info(qca->net_dev, "SPI thread created\n");
 517         while (!kthread_should_stop()) {
 518                 set_current_state(TASK_INTERRUPTIBLE);
 519                 if ((qca->intr_req == qca->intr_svc) &&
 520                     (qca->txr.skb[qca->txr.head] == NULL) &&
 521                     (qca->sync == QCASPI_SYNC_READY))
 522                         schedule();
 523
 524                 set_current_state(TASK_RUNNING);
 525
 526                 netdev_dbg(qca->net_dev, "have work to do. int: %d, tx_skb: %p\n",
 527                            qca->intr_req - qca->intr_svc,
 528                            qca->txr.skb[qca->txr.head]);
 529
 530                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
 531
 532                 if (qca->sync != QCASPI_SYNC_READY) {
 533                         netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",
 534                                    (unsigned int)qca->sync);
 535                         netif_stop_queue(qca->net_dev);
 536                         netif_carrier_off(qca->net_dev);
 537                         qcaspi_flush_tx_ring(qca);
 538                         msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
 539                 }
 540
 541                 if (qca->intr_svc != qca->intr_req) {
 542                         qca->intr_svc = qca->intr_req;
 543                         start_spi_intr_handling(qca, &intr_cause);
 544
 545                         if (intr_cause & SPI_INT_CPU_ON) {
 546                                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);
 547
 548                                 /* not synced. */
 549                                 if (qca->sync != QCASPI_SYNC_READY)
 550                                         continue;
 551
 552                                 qca->stats.device_reset++;
 553                                 netif_wake_queue(qca->net_dev);
 554                                 netif_carrier_on(qca->net_dev);
 555                         }
 556
 557                         if (intr_cause & SPI_INT_RDBUF_ERR) {
 558                                 /* restart sync */
 559                                 netdev_dbg(qca->net_dev, "===> rdbuf error!\n");
 560                                 qca->stats.read_buf_err++;
 561                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 562                                 continue;
 563                         }
 564
 565                         if (intr_cause & SPI_INT_WRBUF_ERR) {
 566                                 /* restart sync */
 567                                 netdev_dbg(qca->net_dev, "===> wrbuf error!\n");
 568                                 qca->stats.write_buf_err++;
 569                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 570                                 continue;
 571                         }
 572
 573                         /* can only handle other interrupts
 574                          * if sync has occurred
 575                          */
 576                         if (qca->sync == QCASPI_SYNC_READY) {
 577                                 if (intr_cause & SPI_INT_PKT_AVLBL)
 578                                         qcaspi_receive(qca);
 579                         }
 580
 581                         end_spi_intr_handling(qca, intr_cause);
 582                 }
 583
 584                 if (qca->sync == QCASPI_SYNC_READY)
 585                         qcaspi_transmit(qca);
 586         }
 587         set_current_state(TASK_RUNNING);
 588         netdev_info(qca->net_dev, "SPI thread exit\n");
 589
 590         return 0;
 591 }
 592
 593 static irqreturn_t
 594 qcaspi_intr_handler(int irq, void *data)
 595 {
 596         struct qcaspi *qca = data;
 597
 598         qca->intr_req++;
 599         if (qca->spi_thread &&
 600             qca->spi_thread->state != TASK_RUNNING)
 601                 wake_up_process(qca->spi_thread);
 602
 603         return IRQ_HANDLED;
 604 }
 605
 606 int
 607 qcaspi_netdev_open(struct net_device *dev)
 608 {
 609         struct qcaspi *qca = netdev_priv(dev);
 610         int ret = 0;
 611
 612         if (!qca)
 613                 return -EINVAL;
 614
 615         qca->intr_req = 1;
 616         qca->intr_svc = 0;
 617         qca->sync = QCASPI_SYNC_UNKNOWN;
 618         qcafrm_fsm_init(&qca->frm_handle);
 619
 620         qca->spi_thread = kthread_run((void *)qcaspi_spi_thread,
 621                                       qca, "%s", dev->name);
 622
 623         if (IS_ERR(qca->spi_thread)) {
 624                 netdev_err(dev, "%s: unable to start kernel thread.\n",
 625                            QCASPI_DRV_NAME);
 626                 return PTR_ERR(qca->spi_thread);
 627         }
 628
 629         ret = request_irq(qca->spi_dev->irq, qcaspi_intr_handler, 0,
 630                           dev->name, qca);
 631         if (ret) {
 632                 netdev_err(dev, "%s: unable to get IRQ %d (irqval=%d).\n",
 633                            QCASPI_DRV_NAME, qca->spi_dev->irq, ret);
 634                 kthread_stop(qca->spi_thread);
 635                 return ret;
 636         }
 637
 638         netif_start_queue(qca->net_dev);
 639
 640         return 0;
 641 }
 642
 643 int
 644 qcaspi_netdev_close(struct net_device *dev)
 645 {
 646         struct qcaspi *qca = netdev_priv(dev);
 647
 648         netif_stop_queue(dev);
 649
 650         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
 651         free_irq(qca->spi_dev->irq, qca);
 652
 653         kthread_stop(qca->spi_thread);
 654         qca->spi_thread = NULL;
 655         qcaspi_flush_tx_ring(qca);
 656
 657         return 0;
 658 }
 659
 660 static netdev_tx_t
 661 qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
 662 {
 663         u32 frame_len;
 664         u8 *ptmp;
 665         struct qcaspi *qca = netdev_priv(dev);
 666         u16 new_tail;
 667         struct sk_buff *tskb;
 668         u8 pad_len = 0;
 669
 670         if (skb->len < QCAFRM_ETHMINLEN)
 671                 pad_len = QCAFRM_ETHMINLEN - skb->len;
 672
 673         if (qca->txr.skb[qca->txr.tail]) {
 674                 netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");
 675                 netif_stop_queue(qca->net_dev);
 676                 qca->stats.ring_full++;
 677                 return NETDEV_TX_BUSY;
 678         }
 679
 680         if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||
 681             (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {
 682                 tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,
 683                                        QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);
 684                 if (!tskb) {
 685                         netdev_dbg(qca->net_dev, "could not allocate tx_buff\n");
 686                         qca->stats.out_of_mem++;
 687                         return NETDEV_TX_BUSY;
 688                 }
 689                 dev_kfree_skb(skb);
 690                 skb = tskb;
 691         }
 692
 693         frame_len = skb->len + pad_len;
 694
 695         ptmp = skb_push(skb, QCAFRM_HEADER_LEN);
 696         qcafrm_create_header(ptmp, frame_len);
 697
 698         if (pad_len) {
 699                 ptmp = skb_put(skb, pad_len);
 700                 memset(ptmp, 0, pad_len);
 701         }
 702
 703         ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);
 704         qcafrm_create_footer(ptmp);
 705
 706         netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",
 707                    skb->len);
 708
 709         qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;
 710
 711         new_tail = qca->txr.tail + 1;
 712         if (new_tail >= qca->txr.count)
 713                 new_tail = 0;
 714
 715         qca->txr.skb[qca->txr.tail] = skb;
 716         qca->txr.tail = new_tail;
 717
 718         if (!qcaspi_tx_ring_has_space(&qca->txr)) {
 719                 netif_stop_queue(qca->net_dev);
 720                 qca->stats.ring_full++;
 721         }
 722
 723         netif_trans_update(dev);
 724
 725         if (qca->spi_thread &&
 726             qca->spi_thread->state != TASK_RUNNING)
 727                 wake_up_process(qca->spi_thread);
 728
 729         return NETDEV_TX_OK;
 730 }
 731
 732 static void
 733 qcaspi_netdev_tx_timeout(struct net_device *dev)
 734 {
 735         struct qcaspi *qca = netdev_priv(dev);
 736
 737         netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
 738                     jiffies, jiffies - dev_trans_start(dev));
 739         qca->net_dev->stats.tx_errors++;
 740         /* Trigger tx queue flush and QCA7000 reset */
 741         qca->sync = QCASPI_SYNC_UNKNOWN;
 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_ip_align(dev, qca->net_dev->mtu +
 764                                                 VLAN_ETH_HLEN);
 765         if (!qca->rx_skb) {
 766                 kfree(qca->rx_buffer);
 767                 netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
 768                 return -ENOBUFS;
 769         }
 770
 771         return 0;
 772 }
 773
 774 static void
 775 qcaspi_netdev_uninit(struct net_device *dev)
 776 {
 777         struct qcaspi *qca = netdev_priv(dev);
 778
 779         kfree(qca->rx_buffer);
 780         qca->buffer_size = 0;
 781         if (qca->rx_skb)
 782                 dev_kfree_skb(qca->rx_skb);
 783 }
 784
 785 static const struct net_device_ops qcaspi_netdev_ops = {
 786         .ndo_init = qcaspi_netdev_init,
 787         .ndo_uninit = qcaspi_netdev_uninit,
 788         .ndo_open = qcaspi_netdev_open,
 789         .ndo_stop = qcaspi_netdev_close,
 790         .ndo_start_xmit = qcaspi_netdev_xmit,
 791         .ndo_set_mac_address = eth_mac_addr,
 792         .ndo_tx_timeout = qcaspi_netdev_tx_timeout,
 793         .ndo_validate_addr = eth_validate_addr,
 794 };
 795
 796 static void
 797 qcaspi_netdev_setup(struct net_device *dev)
 798 {
 799         struct qcaspi *qca = NULL;
 800
 801         dev->netdev_ops = &qcaspi_netdev_ops;
 802         qcaspi_set_ethtool_ops(dev);
 803         dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
 804         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 805         dev->tx_queue_len = 100;
 806
 807         /* MTU range: 46 - 1500 */
 808         dev->min_mtu = QCAFRM_ETHMINMTU;
 809         dev->max_mtu = QCAFRM_ETHMAXMTU;
 810
 811         qca = netdev_priv(dev);
 812         memset(qca, 0, sizeof(struct qcaspi));
 813
 814         memset(&qca->spi_xfer1, 0, sizeof(struct spi_transfer));
 815         memset(&qca->spi_xfer2, 0, sizeof(struct spi_transfer) * 2);
 816
 817         spi_message_init(&qca->spi_msg1);
 818         spi_message_add_tail(&qca->spi_xfer1, &qca->spi_msg1);
 819
 820         spi_message_init(&qca->spi_msg2);
 821         spi_message_add_tail(&qca->spi_xfer2[0], &qca->spi_msg2);
 822         spi_message_add_tail(&qca->spi_xfer2[1], &qca->spi_msg2);
 823
 824         memset(&qca->txr, 0, sizeof(qca->txr));
 825         qca->txr.count = TX_RING_MAX_LEN;
 826 }
 827
 828 static const struct of_device_id qca_spi_of_match[] = {
 829         { .compatible = "qca,qca7000" },
 830         { /* sentinel */ }
 831 };
 832 MODULE_DEVICE_TABLE(of, qca_spi_of_match);
 833
 834 static int
 835 qca_spi_probe(struct spi_device *spi)
 836 {
 837         struct qcaspi *qca = NULL;
 838         struct net_device *qcaspi_devs = NULL;
 839         u8 legacy_mode = 0;
 840         u16 signature;
 841         const char *mac;
 842
 843         if (!spi->dev.of_node) {
 844                 dev_err(&spi->dev, "Missing device tree\n");
 845                 return -EINVAL;
 846         }
 847
 848         legacy_mode = of_property_read_bool(spi->dev.of_node,
 849                                             "qca,legacy-mode");
 850
 851         if (qcaspi_clkspeed == 0) {
 852                 if (spi->max_speed_hz)
 853                         qcaspi_clkspeed = spi->max_speed_hz;
 854                 else
 855                         qcaspi_clkspeed = QCASPI_CLK_SPEED;
 856         }
 857
 858         if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
 859             (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
 860                 dev_info(&spi->dev, "Invalid clkspeed: %d\n",
 861                          qcaspi_clkspeed);
 862                 return -EINVAL;
 863         }
 864
 865         if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
 866             (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
 867                 dev_info(&spi->dev, "Invalid burst len: %d\n",
 868                          qcaspi_burst_len);
 869                 return -EINVAL;
 870         }
 871
 872         if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
 873             (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
 874                 dev_info(&spi->dev, "Invalid pluggable: %d\n",
 875                          qcaspi_pluggable);
 876                 return -EINVAL;
 877         }
 878
 879         dev_info(&spi->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
 880                  QCASPI_DRV_VERSION,
 881                  qcaspi_clkspeed,
 882                  qcaspi_burst_len,
 883                  qcaspi_pluggable);
 884
 885         spi->mode = SPI_MODE_3;
 886         spi->max_speed_hz = qcaspi_clkspeed;
 887         if (spi_setup(spi) < 0) {
 888                 dev_err(&spi->dev, "Unable to setup SPI device\n");
 889                 return -EFAULT;
 890         }
 891
 892         qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
 893         if (!qcaspi_devs)
 894                 return -ENOMEM;
 895
 896         qcaspi_netdev_setup(qcaspi_devs);
 897
 898         qca = netdev_priv(qcaspi_devs);
 899         if (!qca) {
 900                 free_netdev(qcaspi_devs);
 901                 dev_err(&spi->dev, "Fail to retrieve private structure\n");
 902                 return -ENOMEM;
 903         }
 904         qca->net_dev = qcaspi_devs;
 905         qca->spi_dev = spi;
 906         qca->legacy_mode = legacy_mode;
 907
 908         spi_set_drvdata(spi, qcaspi_devs);
 909
 910         mac = of_get_mac_address(spi->dev.of_node);
 911
 912         if (mac)
 913                 ether_addr_copy(qca->net_dev->dev_addr, mac);
 914
 915         if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
 916                 eth_hw_addr_random(qca->net_dev);
 917                 dev_info(&spi->dev, "Using random MAC address: %pM\n",
 918                          qca->net_dev->dev_addr);
 919         }
 920
 921         netif_carrier_off(qca->net_dev);
 922
 923         if (!qcaspi_pluggable) {
 924                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 925                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 926
 927                 if (signature != QCASPI_GOOD_SIGNATURE) {
 928                         dev_err(&spi->dev, "Invalid signature (0x%04X)\n",
 929                                 signature);
 930                         free_netdev(qcaspi_devs);
 931                         return -EFAULT;
 932                 }
 933         }
 934
 935         if (register_netdev(qcaspi_devs)) {
 936                 dev_info(&spi->dev, "Unable to register net device %s\n",
 937                          qcaspi_devs->name);
 938                 free_netdev(qcaspi_devs);
 939                 return -EFAULT;
 940         }
 941
 942         qcaspi_init_device_debugfs(qca);
 943
 944         return 0;
 945 }
 946
 947 static int
 948 qca_spi_remove(struct spi_device *spi)
 949 {
 950         struct net_device *qcaspi_devs = spi_get_drvdata(spi);
 951         struct qcaspi *qca = netdev_priv(qcaspi_devs);
 952
 953         qcaspi_remove_device_debugfs(qca);
 954
 955         unregister_netdev(qcaspi_devs);
 956         free_netdev(qcaspi_devs);
 957
 958         return 0;
 959 }
 960
 961 static const struct spi_device_id qca_spi_id[] = {
 962         { "qca7000", 0 },
 963         { /* sentinel */ }
 964 };
 965 MODULE_DEVICE_TABLE(spi, qca_spi_id);
 966
 967 static struct spi_driver qca_spi_driver = {
 968         .driver = {
 969                 .name   = QCASPI_DRV_NAME,
 970                 .of_match_table = qca_spi_of_match,
 971         },
 972         .id_table = qca_spi_id,
 973         .probe    = qca_spi_probe,
 974         .remove   = qca_spi_remove,
 975 };
 976 module_spi_driver(qca_spi_driver);
 977
 978 MODULE_DESCRIPTION("Qualcomm Atheros SPI Driver");
 979 MODULE_AUTHOR("Qualcomm Atheros Communications");
 980 MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
 981 MODULE_LICENSE("Dual BSD/GPL");
 982 MODULE_VERSION(QCASPI_DRV_VERSION);