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