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_net.h>
  39 #include <linux/sched.h>
  40 #include <linux/skbuff.h>
  41 #include <linux/spi/spi.h>
  42 #include <linux/types.h>
  43
  44 #include "qca_7k.h"
  45 #include "qca_7k_common.h"
  46 #include "qca_debug.h"
  47 #include "qca_spi.h"
  48
  49 #define MAX_DMA_BURST_LEN 5000
  50
  51 /*   Modules parameters     */
  52 #define QCASPI_CLK_SPEED_MIN 1000000
  53 #define QCASPI_CLK_SPEED_MAX 16000000
  54 #define QCASPI_CLK_SPEED     8000000
  55 static int qcaspi_clkspeed;
  56 module_param(qcaspi_clkspeed, int, 0);
  57 MODULE_PARM_DESC(qcaspi_clkspeed, "SPI bus clock speed (Hz). Use 1000000-16000000.");
  58
  59 #define QCASPI_BURST_LEN_MIN 1
  60 #define QCASPI_BURST_LEN_MAX MAX_DMA_BURST_LEN
  61 static int qcaspi_burst_len = MAX_DMA_BURST_LEN;
  62 module_param(qcaspi_burst_len, int, 0);
  63 MODULE_PARM_DESC(qcaspi_burst_len, "Number of data bytes per burst. Use 1-5000.");
  64
  65 #define QCASPI_PLUGGABLE_MIN 0
  66 #define QCASPI_PLUGGABLE_MAX 1
  67 static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;
  68 module_param(qcaspi_pluggable, int, 0);
  69 MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");
  70
  71 #define QCASPI_WRITE_VERIFY_MIN 0
  72 #define QCASPI_WRITE_VERIFY_MAX 3
  73 static int wr_verify = QCASPI_WRITE_VERIFY_MIN;
  74 module_param(wr_verify, int, 0);
  75 MODULE_PARM_DESC(wr_verify, "SPI register write verify trails. Use 0-3.");
  76
  77 #define QCASPI_TX_TIMEOUT (1 * HZ)
  78 #define QCASPI_QCA7K_REBOOT_TIME_MS 1000
  79
  80 static void
  81 start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)
  82 {
  83         *intr_cause = 0;
  84
  85         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
  86         qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
  87         netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);
  88 }
  89
  90 static void
  91 end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)
  92 {
  93         u16 intr_enable = (SPI_INT_CPU_ON |
  94                            SPI_INT_PKT_AVLBL |
  95                            SPI_INT_RDBUF_ERR |
  96                            SPI_INT_WRBUF_ERR);
  97
  98         qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause, 0);
  99         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable, wr_verify);
 100         netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);
 101 }
 102
 103 static u32
 104 qcaspi_write_burst(struct qcaspi *qca, u8 *src, u32 len)
 105 {
 106         __be16 cmd;
 107         struct spi_message msg;
 108         struct spi_transfer transfer[2];
 109         int ret;
 110
 111         memset(&transfer, 0, sizeof(transfer));
 112         spi_message_init(&msg);
 113
 114         cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 115         transfer[0].tx_buf = &cmd;
 116         transfer[0].len = QCASPI_CMD_LEN;
 117         transfer[1].tx_buf = src;
 118         transfer[1].len = len;
 119
 120         spi_message_add_tail(&transfer[0], &msg);
 121         spi_message_add_tail(&transfer[1], &msg);
 122         ret = spi_sync(qca->spi_dev, &msg);
 123
 124         if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {
 125                 qcaspi_spi_error(qca);
 126                 return 0;
 127         }
 128
 129         return len;
 130 }
 131
 132 static u32
 133 qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)
 134 {
 135         struct spi_message msg;
 136         struct spi_transfer transfer;
 137         int ret;
 138
 139         memset(&transfer, 0, sizeof(transfer));
 140         spi_message_init(&msg);
 141
 142         transfer.tx_buf = src;
 143         transfer.len = len;
 144
 145         spi_message_add_tail(&transfer, &msg);
 146         ret = spi_sync(qca->spi_dev, &msg);
 147
 148         if (ret || (msg.actual_length != len)) {
 149                 qcaspi_spi_error(qca);
 150                 return 0;
 151         }
 152
 153         return len;
 154 }
 155
 156 static u32
 157 qcaspi_read_burst(struct qcaspi *qca, u8 *dst, u32 len)
 158 {
 159         struct spi_message msg;
 160         __be16 cmd;
 161         struct spi_transfer transfer[2];
 162         int ret;
 163
 164         memset(&transfer, 0, sizeof(transfer));
 165         spi_message_init(&msg);
 166
 167         cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 168         transfer[0].tx_buf = &cmd;
 169         transfer[0].len = QCASPI_CMD_LEN;
 170         transfer[1].rx_buf = dst;
 171         transfer[1].len = len;
 172
 173         spi_message_add_tail(&transfer[0], &msg);
 174         spi_message_add_tail(&transfer[1], &msg);
 175         ret = spi_sync(qca->spi_dev, &msg);
 176
 177         if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {
 178                 qcaspi_spi_error(qca);
 179                 return 0;
 180         }
 181
 182         return len;
 183 }
 184
 185 static u32
 186 qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)
 187 {
 188         struct spi_message msg;
 189         struct spi_transfer transfer;
 190         int ret;
 191
 192         memset(&transfer, 0, sizeof(transfer));
 193         spi_message_init(&msg);
 194
 195         transfer.rx_buf = dst;
 196         transfer.len = len;
 197
 198         spi_message_add_tail(&transfer, &msg);
 199         ret = spi_sync(qca->spi_dev, &msg);
 200
 201         if (ret || (msg.actual_length != len)) {
 202                 qcaspi_spi_error(qca);
 203                 return 0;
 204         }
 205
 206         return len;
 207 }
 208
 209 static int
 210 qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd)
 211 {
 212         __be16 tx_data;
 213         struct spi_message msg;
 214         struct spi_transfer transfer;
 215         int ret;
 216
 217         memset(&transfer, 0, sizeof(transfer));
 218
 219         spi_message_init(&msg);
 220
 221         tx_data = cpu_to_be16(cmd);
 222         transfer.len = sizeof(cmd);
 223         transfer.tx_buf = &tx_data;
 224         spi_message_add_tail(&transfer, &msg);
 225
 226         ret = spi_sync(qca->spi_dev, &msg);
 227
 228         if (!ret)
 229                 ret = msg.status;
 230
 231         if (ret)
 232                 qcaspi_spi_error(qca);
 233
 234         return ret;
 235 }
 236
 237 static int
 238 qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
 239 {
 240         u32 count;
 241         u32 written;
 242         u32 offset;
 243         u32 len;
 244
 245         len = skb->len;
 246
 247         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len, wr_verify);
 248         if (qca->legacy_mode)
 249                 qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 250
 251         offset = 0;
 252         while (len) {
 253                 count = len;
 254                 if (count > qca->burst_len)
 255                         count = qca->burst_len;
 256
 257                 if (qca->legacy_mode) {
 258                         written = qcaspi_write_legacy(qca,
 259                                                       skb->data + offset,
 260                                                       count);
 261                 } else {
 262                         written = qcaspi_write_burst(qca,
 263                                                      skb->data + offset,
 264                                                      count);
 265                 }
 266
 267                 if (written != count)
 268                         return -1;
 269
 270                 offset += count;
 271                 len -= count;
 272         }
 273
 274         return 0;
 275 }
 276
 277 static int
 278 qcaspi_transmit(struct qcaspi *qca)
 279 {
 280         struct net_device_stats *n_stats = &qca->net_dev->stats;
 281         u16 available = 0;
 282         u32 pkt_len;
 283         u16 new_head;
 284         u16 packets = 0;
 285
 286         if (qca->txr.skb[qca->txr.head] == NULL)
 287                 return 0;
 288
 289         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, &available);
 290
 291         if (available > QCASPI_HW_BUF_LEN) {
 292                 /* This could only happen by interferences on the SPI line.
 293                  * So retry later ...
 294                  */
 295                 qca->stats.buf_avail_err++;
 296                 return -1;
 297         }
 298
 299         while (qca->txr.skb[qca->txr.head]) {
 300                 pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;
 301
 302                 if (available < pkt_len) {
 303                         if (packets == 0)
 304                                 qca->stats.write_buf_miss++;
 305                         break;
 306                 }
 307
 308                 if (qcaspi_tx_frame(qca, qca->txr.skb[qca->txr.head]) == -1) {
 309                         qca->stats.write_err++;
 310                         return -1;
 311                 }
 312
 313                 packets++;
 314                 n_stats->tx_packets++;
 315                 n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;
 316                 available -= pkt_len;
 317
 318                 /* remove the skb from the queue */
 319                 /* XXX After inconsistent lock states netif_tx_lock()
 320                  * has been replaced by netif_tx_lock_bh() and so on.
 321                  */
 322                 netif_tx_lock_bh(qca->net_dev);
 323                 dev_kfree_skb(qca->txr.skb[qca->txr.head]);
 324                 qca->txr.skb[qca->txr.head] = NULL;
 325                 qca->txr.size -= pkt_len;
 326                 new_head = qca->txr.head + 1;
 327                 if (new_head >= qca->txr.count)
 328                         new_head = 0;
 329                 qca->txr.head = new_head;
 330                 if (netif_queue_stopped(qca->net_dev))
 331                         netif_wake_queue(qca->net_dev);
 332                 netif_tx_unlock_bh(qca->net_dev);
 333         }
 334
 335         return 0;
 336 }
 337
 338 static int
 339 qcaspi_receive(struct qcaspi *qca)
 340 {
 341         struct net_device *net_dev = qca->net_dev;
 342         struct net_device_stats *n_stats = &net_dev->stats;
 343         u16 available = 0;
 344         u32 bytes_read;
 345         u8 *cp;
 346
 347         /* Allocate rx SKB if we don't have one available. */
 348         if (!qca->rx_skb) {
 349                 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
 350                                                         net_dev->mtu +
 351                                                         VLAN_ETH_HLEN);
 352                 if (!qca->rx_skb) {
 353                         netdev_dbg(net_dev, "out of RX resources\n");
 354                         qca->stats.out_of_mem++;
 355                         return -1;
 356                 }
 357         }
 358
 359         /* Read the packet size. */
 360         qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);
 361
 362         netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %08x\n",
 363                    available);
 364
 365         if (available > QCASPI_HW_BUF_LEN + QCASPI_HW_PKT_LEN) {
 366                 /* This could only happen by interferences on the SPI line.
 367                  * So retry later ...
 368                  */
 369                 qca->stats.buf_avail_err++;
 370                 return -1;
 371         } else if (available == 0) {
 372                 netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");
 373                 return -1;
 374         }
 375
 376         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available, wr_verify);
 377
 378         if (qca->legacy_mode)
 379                 qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 380
 381         while (available) {
 382                 u32 count = available;
 383
 384                 if (count > qca->burst_len)
 385                         count = qca->burst_len;
 386
 387                 if (qca->legacy_mode) {
 388                         bytes_read = qcaspi_read_legacy(qca, qca->rx_buffer,
 389                                                         count);
 390                 } else {
 391                         bytes_read = qcaspi_read_burst(qca, qca->rx_buffer,
 392                                                        count);
 393                 }
 394
 395                 netdev_dbg(net_dev, "available: %d, byte read: %d\n",
 396                            available, bytes_read);
 397
 398                 if (bytes_read) {
 399                         available -= bytes_read;
 400                 } else {
 401                         qca->stats.read_err++;
 402                         return -1;
 403                 }
 404
 405                 cp = qca->rx_buffer;
 406
 407                 while ((bytes_read--) && (qca->rx_skb)) {
 408                         s32 retcode;
 409
 410                         retcode = qcafrm_fsm_decode(&qca->frm_handle,
 411                                                     qca->rx_skb->data,
 412                                                     skb_tailroom(qca->rx_skb),
 413                                                     *cp);
 414                         cp++;
 415                         switch (retcode) {
 416                         case QCAFRM_GATHER:
 417                         case QCAFRM_NOHEAD:
 418                                 break;
 419                         case QCAFRM_NOTAIL:
 420                                 netdev_dbg(net_dev, "no RX tail\n");
 421                                 n_stats->rx_errors++;
 422                                 n_stats->rx_dropped++;
 423                                 break;
 424                         case QCAFRM_INVLEN:
 425                                 netdev_dbg(net_dev, "invalid RX length\n");
 426                                 n_stats->rx_errors++;
 427                                 n_stats->rx_dropped++;
 428                                 break;
 429                         default:
 430                                 qca->rx_skb->dev = qca->net_dev;
 431                                 n_stats->rx_packets++;
 432                                 n_stats->rx_bytes += retcode;
 433                                 skb_put(qca->rx_skb, retcode);
 434                                 qca->rx_skb->protocol = eth_type_trans(
 435                                         qca->rx_skb, qca->rx_skb->dev);
 436                                 skb_checksum_none_assert(qca->rx_skb);
 437                                 netif_rx(qca->rx_skb);
 438                                 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
 439                                         net_dev->mtu + VLAN_ETH_HLEN);
 440                                 if (!qca->rx_skb) {
 441                                         netdev_dbg(net_dev, "out of RX resources\n");
 442                                         n_stats->rx_errors++;
 443                                         qca->stats.out_of_mem++;
 444                                         break;
 445                                 }
 446                         }
 447                 }
 448         }
 449
 450         return 0;
 451 }
 452
 453 /*   Check that tx ring stores only so much bytes
 454  *   that fit into the internal QCA buffer.
 455  */
 456
 457 static int
 458 qcaspi_tx_ring_has_space(struct tx_ring *txr)
 459 {
 460         if (txr->skb[txr->tail])
 461                 return 0;
 462
 463         return (txr->size + QCAFRM_MAX_LEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
 464 }
 465
 466 /*   Flush the tx ring. This function is only safe to
 467  *   call from the qcaspi_spi_thread.
 468  */
 469
 470 static void
 471 qcaspi_flush_tx_ring(struct qcaspi *qca)
 472 {
 473         int i;
 474
 475         /* XXX After inconsistent lock states netif_tx_lock()
 476          * has been replaced by netif_tx_lock_bh() and so on.
 477          */
 478         netif_tx_lock_bh(qca->net_dev);
 479         for (i = 0; i < TX_RING_MAX_LEN; i++) {
 480                 if (qca->txr.skb[i]) {
 481                         dev_kfree_skb(qca->txr.skb[i]);
 482                         qca->txr.skb[i] = NULL;
 483                         qca->net_dev->stats.tx_dropped++;
 484                 }
 485         }
 486         qca->txr.tail = 0;
 487         qca->txr.head = 0;
 488         qca->txr.size = 0;
 489         netif_tx_unlock_bh(qca->net_dev);
 490 }
 491
 492 static void
 493 qcaspi_qca7k_sync(struct qcaspi *qca, int event)
 494 {
 495         u16 signature = 0;
 496         u16 spi_config;
 497         u16 wrbuf_space = 0;
 498
 499         if (event == QCASPI_EVENT_CPUON) {
 500                 /* Read signature twice, if not valid
 501                  * go back to unknown state.
 502                  */
 503                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 504                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 505                 if (signature != QCASPI_GOOD_SIGNATURE) {
 506                         if (qca->sync == QCASPI_SYNC_READY)
 507                                 qca->stats.bad_signature++;
 508
 509                         qca->sync = QCASPI_SYNC_UNKNOWN;
 510                         netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");
 511                         return;
 512                 } else {
 513                         /* ensure that the WRBUF is empty */
 514                         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,
 515                                              &wrbuf_space);
 516                         if (wrbuf_space != QCASPI_HW_BUF_LEN) {
 517                                 netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");
 518                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 519                         } else {
 520                                 netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");
 521                                 qca->sync = QCASPI_SYNC_READY;
 522                                 return;
 523                         }
 524                 }
 525         }
 526
 527         switch (qca->sync) {
 528         case QCASPI_SYNC_READY:
 529                 /* Check signature twice, if not valid go to unknown state. */
 530                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 531                 if (signature != QCASPI_GOOD_SIGNATURE)
 532                         qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 533
 534                 if (signature != QCASPI_GOOD_SIGNATURE) {
 535                         qca->sync = QCASPI_SYNC_UNKNOWN;
 536                         qca->stats.bad_signature++;
 537                         netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");
 538                         /* don't reset right away */
 539                         return;
 540                 }
 541                 break;
 542         case QCASPI_SYNC_UNKNOWN:
 543                 /* Read signature, if not valid stay in unknown state */
 544                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 545                 if (signature != QCASPI_GOOD_SIGNATURE) {
 546                         netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");
 547                         return;
 548                 }
 549
 550                 /* TODO: use GPIO to reset QCA7000 in legacy mode*/
 551                 netdev_dbg(qca->net_dev, "sync: resetting device.\n");
 552                 qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);
 553                 spi_config |= QCASPI_SLAVE_RESET_BIT;
 554                 qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config, 0);
 555
 556                 qca->sync = QCASPI_SYNC_RESET;
 557                 qca->stats.trig_reset++;
 558                 qca->reset_count = 0;
 559                 break;
 560         case QCASPI_SYNC_RESET:
 561                 qca->reset_count++;
 562                 netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",
 563                            qca->reset_count);
 564                 if (qca->reset_count >= QCASPI_RESET_TIMEOUT) {
 565                         /* reset did not seem to take place, try again */
 566                         qca->sync = QCASPI_SYNC_UNKNOWN;
 567                         qca->stats.reset_timeout++;
 568                         netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");
 569                 }
 570                 break;
 571         }
 572 }
 573
 574 static int
 575 qcaspi_spi_thread(void *data)
 576 {
 577         struct qcaspi *qca = data;
 578         u16 intr_cause = 0;
 579
 580         netdev_info(qca->net_dev, "SPI thread created\n");
 581         while (!kthread_should_stop()) {
 582                 set_current_state(TASK_INTERRUPTIBLE);
 583                 if (kthread_should_park()) {
 584                         netif_tx_disable(qca->net_dev);
 585                         netif_carrier_off(qca->net_dev);
 586                         qcaspi_flush_tx_ring(qca);
 587                         kthread_parkme();
 588                         if (qca->sync == QCASPI_SYNC_READY) {
 589                                 netif_carrier_on(qca->net_dev);
 590                                 netif_wake_queue(qca->net_dev);
 591                         }
 592                         continue;
 593                 }
 594
 595                 if ((qca->intr_req == qca->intr_svc) &&
 596                     !qca->txr.skb[qca->txr.head])
 597                         schedule();
 598
 599                 set_current_state(TASK_RUNNING);
 600
 601                 netdev_dbg(qca->net_dev, "have work to do. int: %d, tx_skb: %p\n",
 602                            qca->intr_req - qca->intr_svc,
 603                            qca->txr.skb[qca->txr.head]);
 604
 605                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
 606
 607                 if (qca->sync != QCASPI_SYNC_READY) {
 608                         netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",
 609                                    (unsigned int)qca->sync);
 610                         netif_stop_queue(qca->net_dev);
 611                         netif_carrier_off(qca->net_dev);
 612                         qcaspi_flush_tx_ring(qca);
 613                         msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
 614                 }
 615
 616                 if (qca->intr_svc != qca->intr_req) {
 617                         qca->intr_svc = qca->intr_req;
 618                         start_spi_intr_handling(qca, &intr_cause);
 619
 620                         if (intr_cause & SPI_INT_CPU_ON) {
 621                                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);
 622
 623                                 /* Frame decoding in progress */
 624                                 if (qca->frm_handle.state != qca->frm_handle.init)
 625                                         qca->net_dev->stats.rx_dropped++;
 626
 627                                 qcafrm_fsm_init_spi(&qca->frm_handle);
 628                                 qca->stats.device_reset++;
 629
 630                                 /* not synced. */
 631                                 if (qca->sync != QCASPI_SYNC_READY)
 632                                         continue;
 633
 634                                 netif_wake_queue(qca->net_dev);
 635                                 netif_carrier_on(qca->net_dev);
 636                         }
 637
 638                         if (intr_cause & SPI_INT_RDBUF_ERR) {
 639                                 /* restart sync */
 640                                 netdev_dbg(qca->net_dev, "===> rdbuf error!\n");
 641                                 qca->stats.read_buf_err++;
 642                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 643                                 continue;
 644                         }
 645
 646                         if (intr_cause & SPI_INT_WRBUF_ERR) {
 647                                 /* restart sync */
 648                                 netdev_dbg(qca->net_dev, "===> wrbuf error!\n");
 649                                 qca->stats.write_buf_err++;
 650                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 651                                 continue;
 652                         }
 653
 654                         /* can only handle other interrupts
 655                          * if sync has occurred
 656                          */
 657                         if (qca->sync == QCASPI_SYNC_READY) {
 658                                 if (intr_cause & SPI_INT_PKT_AVLBL)
 659                                         qcaspi_receive(qca);
 660                         }
 661
 662                         end_spi_intr_handling(qca, intr_cause);
 663                 }
 664
 665                 if (qca->sync == QCASPI_SYNC_READY)
 666                         qcaspi_transmit(qca);
 667         }
 668         set_current_state(TASK_RUNNING);
 669         netdev_info(qca->net_dev, "SPI thread exit\n");
 670
 671         return 0;
 672 }
 673
 674 static irqreturn_t
 675 qcaspi_intr_handler(int irq, void *data)
 676 {
 677         struct qcaspi *qca = data;
 678
 679         qca->intr_req++;
 680         if (qca->spi_thread)
 681                 wake_up_process(qca->spi_thread);
 682
 683         return IRQ_HANDLED;
 684 }
 685
 686 static int
 687 qcaspi_netdev_open(struct net_device *dev)
 688 {
 689         struct qcaspi *qca = netdev_priv(dev);
 690         int ret = 0;
 691
 692         if (!qca)
 693                 return -EINVAL;
 694
 695         qca->intr_req = 1;
 696         qca->intr_svc = 0;
 697         qca->sync = QCASPI_SYNC_UNKNOWN;
 698         qcafrm_fsm_init_spi(&qca->frm_handle);
 699
 700         qca->spi_thread = kthread_run((void *)qcaspi_spi_thread,
 701                                       qca, "%s", dev->name);
 702
 703         if (IS_ERR(qca->spi_thread)) {
 704                 netdev_err(dev, "%s: unable to start kernel thread.\n",
 705                            QCASPI_DRV_NAME);
 706                 return PTR_ERR(qca->spi_thread);
 707         }
 708
 709         ret = request_irq(qca->spi_dev->irq, qcaspi_intr_handler, 0,
 710                           dev->name, qca);
 711         if (ret) {
 712                 netdev_err(dev, "%s: unable to get IRQ %d (irqval=%d).\n",
 713                            QCASPI_DRV_NAME, qca->spi_dev->irq, ret);
 714                 kthread_stop(qca->spi_thread);
 715                 return ret;
 716         }
 717
 718         /* SPI thread takes care of TX queue */
 719
 720         return 0;
 721 }
 722
 723 static int
 724 qcaspi_netdev_close(struct net_device *dev)
 725 {
 726         struct qcaspi *qca = netdev_priv(dev);
 727
 728         netif_stop_queue(dev);
 729
 730         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
 731         free_irq(qca->spi_dev->irq, qca);
 732
 733         kthread_stop(qca->spi_thread);
 734         qca->spi_thread = NULL;
 735         qcaspi_flush_tx_ring(qca);
 736
 737         return 0;
 738 }
 739
 740 static netdev_tx_t
 741 qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
 742 {
 743         u32 frame_len;
 744         u8 *ptmp;
 745         struct qcaspi *qca = netdev_priv(dev);
 746         u16 new_tail;
 747         struct sk_buff *tskb;
 748         u8 pad_len = 0;
 749
 750         if (skb->len < QCAFRM_MIN_LEN)
 751                 pad_len = QCAFRM_MIN_LEN - skb->len;
 752
 753         if (qca->txr.skb[qca->txr.tail]) {
 754                 netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");
 755                 netif_stop_queue(qca->net_dev);
 756                 qca->stats.ring_full++;
 757                 return NETDEV_TX_BUSY;
 758         }
 759
 760         if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||
 761             (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {
 762                 tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,
 763                                        QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);
 764                 if (!tskb) {
 765                         qca->stats.out_of_mem++;
 766                         return NETDEV_TX_BUSY;
 767                 }
 768                 dev_kfree_skb(skb);
 769                 skb = tskb;
 770         }
 771
 772         frame_len = skb->len + pad_len;
 773
 774         ptmp = skb_push(skb, QCAFRM_HEADER_LEN);
 775         qcafrm_create_header(ptmp, frame_len);
 776
 777         if (pad_len) {
 778                 ptmp = skb_put_zero(skb, pad_len);
 779         }
 780
 781         ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);
 782         qcafrm_create_footer(ptmp);
 783
 784         netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",
 785                    skb->len);
 786
 787         qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;
 788
 789         new_tail = qca->txr.tail + 1;
 790         if (new_tail >= qca->txr.count)
 791                 new_tail = 0;
 792
 793         qca->txr.skb[qca->txr.tail] = skb;
 794         qca->txr.tail = new_tail;
 795
 796         if (!qcaspi_tx_ring_has_space(&qca->txr)) {
 797                 netif_stop_queue(qca->net_dev);
 798                 qca->stats.ring_full++;
 799         }
 800
 801         netif_trans_update(dev);
 802
 803         if (qca->spi_thread)
 804                 wake_up_process(qca->spi_thread);
 805
 806         return NETDEV_TX_OK;
 807 }
 808
 809 static void
 810 qcaspi_netdev_tx_timeout(struct net_device *dev, unsigned int txqueue)
 811 {
 812         struct qcaspi *qca = netdev_priv(dev);
 813
 814         netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
 815                     jiffies, jiffies - dev_trans_start(dev));
 816         qca->net_dev->stats.tx_errors++;
 817         /* Trigger tx queue flush and QCA7000 reset */
 818         qca->sync = QCASPI_SYNC_UNKNOWN;
 819
 820         if (qca->spi_thread)
 821                 wake_up_process(qca->spi_thread);
 822 }
 823
 824 static int
 825 qcaspi_netdev_init(struct net_device *dev)
 826 {
 827         struct qcaspi *qca = netdev_priv(dev);
 828
 829         dev->mtu = QCAFRM_MAX_MTU;
 830         dev->type = ARPHRD_ETHER;
 831         qca->clkspeed = qcaspi_clkspeed;
 832         qca->burst_len = qcaspi_burst_len;
 833         qca->spi_thread = NULL;
 834         qca->buffer_size = (dev->mtu + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +
 835                 QCAFRM_FOOTER_LEN + 4) * 4;
 836
 837         memset(&qca->stats, 0, sizeof(struct qcaspi_stats));
 838
 839         qca->rx_buffer = kmalloc(qca->buffer_size, GFP_KERNEL);
 840         if (!qca->rx_buffer)
 841                 return -ENOBUFS;
 842
 843         qca->rx_skb = netdev_alloc_skb_ip_align(dev, qca->net_dev->mtu +
 844                                                 VLAN_ETH_HLEN);
 845         if (!qca->rx_skb) {
 846                 kfree(qca->rx_buffer);
 847                 netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
 848                 return -ENOBUFS;
 849         }
 850
 851         return 0;
 852 }
 853
 854 static void
 855 qcaspi_netdev_uninit(struct net_device *dev)
 856 {
 857         struct qcaspi *qca = netdev_priv(dev);
 858
 859         kfree(qca->rx_buffer);
 860         qca->buffer_size = 0;
 861         dev_kfree_skb(qca->rx_skb);
 862 }
 863
 864 static const struct net_device_ops qcaspi_netdev_ops = {
 865         .ndo_init = qcaspi_netdev_init,
 866         .ndo_uninit = qcaspi_netdev_uninit,
 867         .ndo_open = qcaspi_netdev_open,
 868         .ndo_stop = qcaspi_netdev_close,
 869         .ndo_start_xmit = qcaspi_netdev_xmit,
 870         .ndo_set_mac_address = eth_mac_addr,
 871         .ndo_tx_timeout = qcaspi_netdev_tx_timeout,
 872         .ndo_validate_addr = eth_validate_addr,
 873 };
 874
 875 static void
 876 qcaspi_netdev_setup(struct net_device *dev)
 877 {
 878         struct qcaspi *qca = NULL;
 879
 880         dev->netdev_ops = &qcaspi_netdev_ops;
 881         qcaspi_set_ethtool_ops(dev);
 882         dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
 883         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 884         dev->tx_queue_len = 100;
 885
 886         /* MTU range: 46 - 1500 */
 887         dev->min_mtu = QCAFRM_MIN_MTU;
 888         dev->max_mtu = QCAFRM_MAX_MTU;
 889
 890         qca = netdev_priv(dev);
 891         memset(qca, 0, sizeof(struct qcaspi));
 892
 893         memset(&qca->txr, 0, sizeof(qca->txr));
 894         qca->txr.count = TX_RING_MAX_LEN;
 895 }
 896
 897 static const struct of_device_id qca_spi_of_match[] = {
 898         { .compatible = "qca,qca7000" },
 899         { /* sentinel */ }
 900 };
 901 MODULE_DEVICE_TABLE(of, qca_spi_of_match);
 902
 903 static int
 904 qca_spi_probe(struct spi_device *spi)
 905 {
 906         struct qcaspi *qca = NULL;
 907         struct net_device *qcaspi_devs = NULL;
 908         u8 legacy_mode = 0;
 909         u16 signature;
 910         int ret;
 911
 912         if (!spi->dev.of_node) {
 913                 dev_err(&spi->dev, "Missing device tree\n");
 914                 return -EINVAL;
 915         }
 916
 917         legacy_mode = of_property_read_bool(spi->dev.of_node,
 918                                             "qca,legacy-mode");
 919
 920         if (qcaspi_clkspeed == 0) {
 921                 if (spi->max_speed_hz)
 922                         qcaspi_clkspeed = spi->max_speed_hz;
 923                 else
 924                         qcaspi_clkspeed = QCASPI_CLK_SPEED;
 925         }
 926
 927         if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
 928             (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
 929                 dev_err(&spi->dev, "Invalid clkspeed: %d\n",
 930                         qcaspi_clkspeed);
 931                 return -EINVAL;
 932         }
 933
 934         if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
 935             (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
 936                 dev_err(&spi->dev, "Invalid burst len: %d\n",
 937                         qcaspi_burst_len);
 938                 return -EINVAL;
 939         }
 940
 941         if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
 942             (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
 943                 dev_err(&spi->dev, "Invalid pluggable: %d\n",
 944                         qcaspi_pluggable);
 945                 return -EINVAL;
 946         }
 947
 948         if (wr_verify < QCASPI_WRITE_VERIFY_MIN ||
 949             wr_verify > QCASPI_WRITE_VERIFY_MAX) {
 950                 dev_err(&spi->dev, "Invalid write verify: %d\n",
 951                         wr_verify);
 952                 return -EINVAL;
 953         }
 954
 955         dev_info(&spi->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
 956                  QCASPI_DRV_VERSION,
 957                  qcaspi_clkspeed,
 958                  qcaspi_burst_len,
 959                  qcaspi_pluggable);
 960
 961         spi->mode = SPI_MODE_3;
 962         spi->max_speed_hz = qcaspi_clkspeed;
 963         if (spi_setup(spi) < 0) {
 964                 dev_err(&spi->dev, "Unable to setup SPI device\n");
 965                 return -EFAULT;
 966         }
 967
 968         qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
 969         if (!qcaspi_devs)
 970                 return -ENOMEM;
 971
 972         qcaspi_netdev_setup(qcaspi_devs);
 973         SET_NETDEV_DEV(qcaspi_devs, &spi->dev);
 974
 975         qca = netdev_priv(qcaspi_devs);
 976         if (!qca) {
 977                 free_netdev(qcaspi_devs);
 978                 dev_err(&spi->dev, "Fail to retrieve private structure\n");
 979                 return -ENOMEM;
 980         }
 981         qca->net_dev = qcaspi_devs;
 982         qca->spi_dev = spi;
 983         qca->legacy_mode = legacy_mode;
 984
 985         spi_set_drvdata(spi, qcaspi_devs);
 986
 987         ret = of_get_ethdev_address(spi->dev.of_node, qca->net_dev);
 988         if (ret) {
 989                 eth_hw_addr_random(qca->net_dev);
 990                 dev_info(&spi->dev, "Using random MAC address: %pM\n",
 991                          qca->net_dev->dev_addr);
 992         }
 993
 994         netif_carrier_off(qca->net_dev);
 995
 996         if (!qcaspi_pluggable) {
 997                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 998                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 999
1000                 if (signature != QCASPI_GOOD_SIGNATURE) {
1001                         dev_err(&spi->dev, "Invalid signature (0x%04X)\n",
1002                                 signature);
1003                         free_netdev(qcaspi_devs);
1004                         return -EFAULT;
1005                 }
1006         }
1007
1008         if (register_netdev(qcaspi_devs)) {
1009                 dev_err(&spi->dev, "Unable to register net device %s\n",
1010                         qcaspi_devs->name);
1011                 free_netdev(qcaspi_devs);
1012                 return -EFAULT;
1013         }
1014
1015         qcaspi_init_device_debugfs(qca);
1016
1017         return 0;
1018 }
1019
1020 static void
1021 qca_spi_remove(struct spi_device *spi)
1022 {
1023         struct net_device *qcaspi_devs = spi_get_drvdata(spi);
1024         struct qcaspi *qca = netdev_priv(qcaspi_devs);
1025
1026         qcaspi_remove_device_debugfs(qca);
1027
1028         unregister_netdev(qcaspi_devs);
1029         free_netdev(qcaspi_devs);
1030 }
1031
1032 static const struct spi_device_id qca_spi_id[] = {
1033         { "qca7000", 0 },
1034         { /* sentinel */ }
1035 };
1036 MODULE_DEVICE_TABLE(spi, qca_spi_id);
1037
1038 static struct spi_driver qca_spi_driver = {
1039         .driver = {
1040                 .name   = QCASPI_DRV_NAME,
1041                 .of_match_table = qca_spi_of_match,
1042         },
1043         .id_table = qca_spi_id,
1044         .probe    = qca_spi_probe,
1045         .remove   = qca_spi_remove,
1046 };
1047 module_spi_driver(qca_spi_driver);
1048
1049 MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 SPI Driver");
1050 MODULE_AUTHOR("Qualcomm Atheros Communications");
1051 MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
1052 MODULE_LICENSE("Dual BSD/GPL");
1053 MODULE_VERSION(QCASPI_DRV_VERSION);