drivers/net/ethernet/qualcomm/qca_spi.c

   1 // SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
   2 /*
   3  *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
   4  *   Copyright (c) 2014, I2SE GmbH
   5  */
   6
   7 /*   This module implements the Qualcomm Atheros SPI protocol for
   8  *   kernel-based SPI device; it is essentially an Ethernet-to-SPI
   9  *   serial converter;
  10  */
  11
  12 #include <linux/errno.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/if_arp.h>
  15 #include <linux/if_ether.h>
  16 #include <linux/init.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/jiffies.h>
  19 #include <linux/kernel.h>
  20 #include <linux/kthread.h>
  21 #include <linux/module.h>
  22 #include <linux/moduleparam.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/of.h>
  25 #include <linux/of_net.h>
  26 #include <linux/sched.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/spi/spi.h>
  29 #include <linux/types.h>
  30
  31 #include "qca_7k.h"
  32 #include "qca_7k_common.h"
  33 #include "qca_debug.h"
  34 #include "qca_spi.h"
  35
  36 #define MAX_DMA_BURST_LEN 5000
  37
  38 #define SPI_INTR        0
  39 #define SPI_RESET       1
  40
  41 /*   Modules parameters     */
  42 #define QCASPI_CLK_SPEED_MIN 1000000
  43 #define QCASPI_CLK_SPEED_MAX 16000000
  44 #define QCASPI_CLK_SPEED     8000000
  45 static int qcaspi_clkspeed;
  46 module_param(qcaspi_clkspeed, int, 0);
  47 MODULE_PARM_DESC(qcaspi_clkspeed, "SPI bus clock speed (Hz). Use 1000000-16000000.");
  48
  49 #define QCASPI_BURST_LEN_MIN 1
  50 #define QCASPI_BURST_LEN_MAX MAX_DMA_BURST_LEN
  51 static int qcaspi_burst_len = MAX_DMA_BURST_LEN;
  52 module_param(qcaspi_burst_len, int, 0);
  53 MODULE_PARM_DESC(qcaspi_burst_len, "Number of data bytes per burst. Use 1-5000.");
  54
  55 #define QCASPI_PLUGGABLE_MIN 0
  56 #define QCASPI_PLUGGABLE_MAX 1
  57 static int qcaspi_pluggable = QCASPI_PLUGGABLE_MAX;
  58 module_param(qcaspi_pluggable, int, 0);
  59 MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");
  60
  61 #define QCASPI_WRITE_VERIFY_MIN 0
  62 #define QCASPI_WRITE_VERIFY_MAX 3
  63 static int wr_verify = QCASPI_WRITE_VERIFY_MIN;
  64 module_param(wr_verify, int, 0);
  65 MODULE_PARM_DESC(wr_verify, "SPI register write verify trails. Use 0-3.");
  66
  67 #define QCASPI_TX_TIMEOUT (1 * HZ)
  68 #define QCASPI_QCA7K_REBOOT_TIME_MS 1000
  69
  70 static void
  71 start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)
  72 {
  73         *intr_cause = 0;
  74
  75         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
  76         qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
  77         netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);
  78 }
  79
  80 static void
  81 end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)
  82 {
  83         u16 intr_enable = (SPI_INT_CPU_ON |
  84                            SPI_INT_PKT_AVLBL |
  85                            SPI_INT_RDBUF_ERR |
  86                            SPI_INT_WRBUF_ERR);
  87
  88         qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause, 0);
  89         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable, wr_verify);
  90         netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);
  91 }
  92
  93 static u32
  94 qcaspi_write_burst(struct qcaspi *qca, u8 *src, u32 len)
  95 {
  96         __be16 cmd;
  97         struct spi_message msg;
  98         struct spi_transfer transfer[2];
  99         int ret;
 100
 101         memset(&transfer, 0, sizeof(transfer));
 102         spi_message_init(&msg);
 103
 104         cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 105         transfer[0].tx_buf = &cmd;
 106         transfer[0].len = QCASPI_CMD_LEN;
 107         transfer[1].tx_buf = src;
 108         transfer[1].len = len;
 109
 110         spi_message_add_tail(&transfer[0], &msg);
 111         spi_message_add_tail(&transfer[1], &msg);
 112         ret = spi_sync(qca->spi_dev, &msg);
 113
 114         if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {
 115                 qcaspi_spi_error(qca);
 116                 return 0;
 117         }
 118
 119         return len;
 120 }
 121
 122 static u32
 123 qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)
 124 {
 125         struct spi_message msg;
 126         struct spi_transfer transfer;
 127         int ret;
 128
 129         memset(&transfer, 0, sizeof(transfer));
 130         spi_message_init(&msg);
 131
 132         transfer.tx_buf = src;
 133         transfer.len = len;
 134
 135         spi_message_add_tail(&transfer, &msg);
 136         ret = spi_sync(qca->spi_dev, &msg);
 137
 138         if (ret || (msg.actual_length != len)) {
 139                 qcaspi_spi_error(qca);
 140                 return 0;
 141         }
 142
 143         return len;
 144 }
 145
 146 static u32
 147 qcaspi_read_burst(struct qcaspi *qca, u8 *dst, u32 len)
 148 {
 149         struct spi_message msg;
 150         __be16 cmd;
 151         struct spi_transfer transfer[2];
 152         int ret;
 153
 154         memset(&transfer, 0, sizeof(transfer));
 155         spi_message_init(&msg);
 156
 157         cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 158         transfer[0].tx_buf = &cmd;
 159         transfer[0].len = QCASPI_CMD_LEN;
 160         transfer[1].rx_buf = dst;
 161         transfer[1].len = len;
 162
 163         spi_message_add_tail(&transfer[0], &msg);
 164         spi_message_add_tail(&transfer[1], &msg);
 165         ret = spi_sync(qca->spi_dev, &msg);
 166
 167         if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {
 168                 qcaspi_spi_error(qca);
 169                 return 0;
 170         }
 171
 172         return len;
 173 }
 174
 175 static u32
 176 qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)
 177 {
 178         struct spi_message msg;
 179         struct spi_transfer transfer;
 180         int ret;
 181
 182         memset(&transfer, 0, sizeof(transfer));
 183         spi_message_init(&msg);
 184
 185         transfer.rx_buf = dst;
 186         transfer.len = len;
 187
 188         spi_message_add_tail(&transfer, &msg);
 189         ret = spi_sync(qca->spi_dev, &msg);
 190
 191         if (ret || (msg.actual_length != len)) {
 192                 qcaspi_spi_error(qca);
 193                 return 0;
 194         }
 195
 196         return len;
 197 }
 198
 199 static int
 200 qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd)
 201 {
 202         __be16 tx_data;
 203         struct spi_message msg;
 204         struct spi_transfer transfer;
 205         int ret;
 206
 207         memset(&transfer, 0, sizeof(transfer));
 208
 209         spi_message_init(&msg);
 210
 211         tx_data = cpu_to_be16(cmd);
 212         transfer.len = sizeof(cmd);
 213         transfer.tx_buf = &tx_data;
 214         spi_message_add_tail(&transfer, &msg);
 215
 216         ret = spi_sync(qca->spi_dev, &msg);
 217
 218         if (!ret)
 219                 ret = msg.status;
 220
 221         if (ret)
 222                 qcaspi_spi_error(qca);
 223
 224         return ret;
 225 }
 226
 227 static int
 228 qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
 229 {
 230         u32 count;
 231         u32 written;
 232         u32 offset;
 233         u32 len;
 234
 235         len = skb->len;
 236
 237         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len, wr_verify);
 238         if (qca->legacy_mode)
 239                 qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 240
 241         offset = 0;
 242         while (len) {
 243                 count = len;
 244                 if (count > qca->burst_len)
 245                         count = qca->burst_len;
 246
 247                 if (qca->legacy_mode) {
 248                         written = qcaspi_write_legacy(qca,
 249                                                       skb->data + offset,
 250                                                       count);
 251                 } else {
 252                         written = qcaspi_write_burst(qca,
 253                                                      skb->data + offset,
 254                                                      count);
 255                 }
 256
 257                 if (written != count)
 258                         return -1;
 259
 260                 offset += count;
 261                 len -= count;
 262         }
 263
 264         return 0;
 265 }
 266
 267 static int
 268 qcaspi_transmit(struct qcaspi *qca)
 269 {
 270         struct net_device_stats *n_stats = &qca->net_dev->stats;
 271         u16 available = 0;
 272         u32 pkt_len;
 273         u16 new_head;
 274         u16 packets = 0;
 275
 276         if (qca->txr.skb[qca->txr.head] == NULL)
 277                 return 0;
 278
 279         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, &available);
 280
 281         if (available > QCASPI_HW_BUF_LEN) {
 282                 /* This could only happen by interferences on the SPI line.
 283                  * So retry later ...
 284                  */
 285                 qca->stats.buf_avail_err++;
 286                 return -1;
 287         }
 288
 289         while (qca->txr.skb[qca->txr.head]) {
 290                 pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;
 291
 292                 if (available < pkt_len) {
 293                         if (packets == 0)
 294                                 qca->stats.write_buf_miss++;
 295                         break;
 296                 }
 297
 298                 if (qcaspi_tx_frame(qca, qca->txr.skb[qca->txr.head]) == -1) {
 299                         qca->stats.write_err++;
 300                         return -1;
 301                 }
 302
 303                 packets++;
 304                 n_stats->tx_packets++;
 305                 n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;
 306                 available -= pkt_len;
 307
 308                 /* remove the skb from the queue */
 309                 /* XXX After inconsistent lock states netif_tx_lock()
 310                  * has been replaced by netif_tx_lock_bh() and so on.
 311                  */
 312                 netif_tx_lock_bh(qca->net_dev);
 313                 dev_kfree_skb(qca->txr.skb[qca->txr.head]);
 314                 qca->txr.skb[qca->txr.head] = NULL;
 315                 qca->txr.size -= pkt_len;
 316                 new_head = qca->txr.head + 1;
 317                 if (new_head >= qca->txr.count)
 318                         new_head = 0;
 319                 qca->txr.head = new_head;
 320                 if (netif_queue_stopped(qca->net_dev))
 321                         netif_wake_queue(qca->net_dev);
 322                 netif_tx_unlock_bh(qca->net_dev);
 323         }
 324
 325         return 0;
 326 }
 327
 328 static int
 329 qcaspi_receive(struct qcaspi *qca)
 330 {
 331         struct net_device *net_dev = qca->net_dev;
 332         struct net_device_stats *n_stats = &net_dev->stats;
 333         u16 available = 0;
 334         u32 bytes_read;
 335         u8 *cp;
 336
 337         /* Allocate rx SKB if we don't have one available. */
 338         if (!qca->rx_skb) {
 339                 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
 340                                                         net_dev->mtu +
 341                                                         VLAN_ETH_HLEN);
 342                 if (!qca->rx_skb) {
 343                         netdev_dbg(net_dev, "out of RX resources\n");
 344                         qca->stats.out_of_mem++;
 345                         return -1;
 346                 }
 347         }
 348
 349         /* Read the packet size. */
 350         qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);
 351
 352         netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %04x\n",
 353                    available);
 354
 355         if (available > QCASPI_HW_BUF_LEN + QCASPI_HW_PKT_LEN) {
 356                 /* This could only happen by interferences on the SPI line.
 357                  * So retry later ...
 358                  */
 359                 qca->stats.buf_avail_err++;
 360                 return -1;
 361         } else if (available == 0) {
 362                 netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");
 363                 return -1;
 364         }
 365
 366         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available, wr_verify);
 367
 368         if (qca->legacy_mode)
 369                 qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 370
 371         while (available) {
 372                 u32 count = available;
 373
 374                 if (count > qca->burst_len)
 375                         count = qca->burst_len;
 376
 377                 if (qca->legacy_mode) {
 378                         bytes_read = qcaspi_read_legacy(qca, qca->rx_buffer,
 379                                                         count);
 380                 } else {
 381                         bytes_read = qcaspi_read_burst(qca, qca->rx_buffer,
 382                                                        count);
 383                 }
 384
 385                 netdev_dbg(net_dev, "available: %d, byte read: %d\n",
 386                            available, bytes_read);
 387
 388                 if (bytes_read) {
 389                         available -= bytes_read;
 390                 } else {
 391                         qca->stats.read_err++;
 392                         return -1;
 393                 }
 394
 395                 cp = qca->rx_buffer;
 396
 397                 while ((bytes_read--) && (qca->rx_skb)) {
 398                         s32 retcode;
 399
 400                         retcode = qcafrm_fsm_decode(&qca->frm_handle,
 401                                                     qca->rx_skb->data,
 402                                                     skb_tailroom(qca->rx_skb),
 403                                                     *cp);
 404                         cp++;
 405                         switch (retcode) {
 406                         case QCAFRM_GATHER:
 407                         case QCAFRM_NOHEAD:
 408                                 break;
 409                         case QCAFRM_NOTAIL:
 410                                 netdev_dbg(net_dev, "no RX tail\n");
 411                                 n_stats->rx_errors++;
 412                                 n_stats->rx_dropped++;
 413                                 break;
 414                         case QCAFRM_INVLEN:
 415                                 netdev_dbg(net_dev, "invalid RX length\n");
 416                                 n_stats->rx_errors++;
 417                                 n_stats->rx_dropped++;
 418                                 break;
 419                         default:
 420                                 qca->rx_skb->dev = qca->net_dev;
 421                                 n_stats->rx_packets++;
 422                                 n_stats->rx_bytes += retcode;
 423                                 skb_put(qca->rx_skb, retcode);
 424                                 qca->rx_skb->protocol = eth_type_trans(
 425                                         qca->rx_skb, qca->rx_skb->dev);
 426                                 skb_checksum_none_assert(qca->rx_skb);
 427                                 netif_rx(qca->rx_skb);
 428                                 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
 429                                         net_dev->mtu + VLAN_ETH_HLEN);
 430                                 if (!qca->rx_skb) {
 431                                         netdev_dbg(net_dev, "out of RX resources\n");
 432                                         n_stats->rx_errors++;
 433                                         qca->stats.out_of_mem++;
 434                                         break;
 435                                 }
 436                         }
 437                 }
 438         }
 439
 440         return 0;
 441 }
 442
 443 /*   Check that tx ring stores only so much bytes
 444  *   that fit into the internal QCA buffer.
 445  */
 446
 447 static int
 448 qcaspi_tx_ring_has_space(struct tx_ring *txr)
 449 {
 450         if (txr->skb[txr->tail])
 451                 return 0;
 452
 453         return (txr->size + QCAFRM_MAX_LEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
 454 }
 455
 456 /*   Flush the tx ring. This function is only safe to
 457  *   call from the qcaspi_spi_thread.
 458  */
 459
 460 static void
 461 qcaspi_flush_tx_ring(struct qcaspi *qca)
 462 {
 463         int i;
 464
 465         /* XXX After inconsistent lock states netif_tx_lock()
 466          * has been replaced by netif_tx_lock_bh() and so on.
 467          */
 468         netif_tx_lock_bh(qca->net_dev);
 469         for (i = 0; i < QCASPI_TX_RING_MAX_LEN; i++) {
 470                 if (qca->txr.skb[i]) {
 471                         dev_kfree_skb(qca->txr.skb[i]);
 472                         qca->txr.skb[i] = NULL;
 473                         qca->net_dev->stats.tx_dropped++;
 474                 }
 475         }
 476         qca->txr.tail = 0;
 477         qca->txr.head = 0;
 478         qca->txr.size = 0;
 479         netif_tx_unlock_bh(qca->net_dev);
 480 }
 481
 482 static void
 483 qcaspi_qca7k_sync(struct qcaspi *qca, int event)
 484 {
 485         u16 signature = 0;
 486         u16 spi_config;
 487         u16 wrbuf_space = 0;
 488
 489         if (event == QCASPI_EVENT_CPUON) {
 490                 /* Read signature twice, if not valid
 491                  * go back to unknown state.
 492                  */
 493                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 494                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 495                 if (signature != QCASPI_GOOD_SIGNATURE) {
 496                         if (qca->sync == QCASPI_SYNC_READY)
 497                                 qca->stats.bad_signature++;
 498
 499                         set_bit(SPI_RESET, &qca->flags);
 500                         netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");
 501                         return;
 502                 } else {
 503                         /* ensure that the WRBUF is empty */
 504                         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,
 505                                              &wrbuf_space);
 506                         if (wrbuf_space != QCASPI_HW_BUF_LEN) {
 507                                 netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");
 508                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 509                                 qca->stats.buf_avail_err++;
 510                         } else {
 511                                 netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");
 512                                 qca->sync = QCASPI_SYNC_READY;
 513                                 return;
 514                         }
 515                 }
 516         } else {
 517                 /* Handle reset only on QCASPI_EVENT_UPDATE */
 518                 if (test_and_clear_bit(SPI_RESET, &qca->flags))
 519                         qca->sync = QCASPI_SYNC_UNKNOWN;
 520         }
 521
 522         switch (qca->sync) {
 523         case QCASPI_SYNC_READY:
 524                 /* Check signature twice, if not valid go to unknown state. */
 525                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 526                 if (signature != QCASPI_GOOD_SIGNATURE)
 527                         qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 528
 529                 if (signature != QCASPI_GOOD_SIGNATURE) {
 530                         set_bit(SPI_RESET, &qca->flags);
 531                         qca->stats.bad_signature++;
 532                         netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");
 533                         /* don't reset right away */
 534                         return;
 535                 }
 536                 break;
 537         case QCASPI_SYNC_UNKNOWN:
 538                 /* Read signature, if not valid stay in unknown state */
 539                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 540                 if (signature != QCASPI_GOOD_SIGNATURE) {
 541                         netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");
 542                         return;
 543                 }
 544
 545                 /* TODO: use GPIO to reset QCA7000 in legacy mode*/
 546                 netdev_dbg(qca->net_dev, "sync: resetting device.\n");
 547                 qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);
 548                 spi_config |= QCASPI_SLAVE_RESET_BIT;
 549                 qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config, 0);
 550
 551                 qca->sync = QCASPI_SYNC_RESET;
 552                 qca->stats.trig_reset++;
 553                 qca->reset_count = 0;
 554                 break;
 555         case QCASPI_SYNC_RESET:
 556                 qca->reset_count++;
 557                 netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",
 558                            qca->reset_count);
 559                 if (qca->reset_count >= QCASPI_RESET_TIMEOUT) {
 560                         /* reset did not seem to take place, try again */
 561                         set_bit(SPI_RESET, &qca->flags);
 562                         qca->stats.reset_timeout++;
 563                         netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");
 564                 }
 565                 break;
 566         }
 567 }
 568
 569 static int
 570 qcaspi_spi_thread(void *data)
 571 {
 572         struct qcaspi *qca = data;
 573         u16 intr_cause = 0;
 574
 575         netdev_info(qca->net_dev, "SPI thread created\n");
 576         while (!kthread_should_stop()) {
 577                 set_current_state(TASK_INTERRUPTIBLE);
 578                 if (kthread_should_park()) {
 579                         netif_tx_disable(qca->net_dev);
 580                         netif_carrier_off(qca->net_dev);
 581                         qcaspi_flush_tx_ring(qca);
 582                         kthread_parkme();
 583                         if (qca->sync == QCASPI_SYNC_READY) {
 584                                 netif_carrier_on(qca->net_dev);
 585                                 netif_wake_queue(qca->net_dev);
 586                         }
 587                         continue;
 588                 }
 589
 590                 if (!qca->flags &&
 591                     !qca->txr.skb[qca->txr.head])
 592                         schedule();
 593
 594                 set_current_state(TASK_RUNNING);
 595
 596                 netdev_dbg(qca->net_dev, "have work to do. int: %lu, tx_skb: %p\n",
 597                            qca->flags,
 598                            qca->txr.skb[qca->txr.head]);
 599
 600                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
 601
 602                 if (qca->sync != QCASPI_SYNC_READY) {
 603                         netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",
 604                                    (unsigned int)qca->sync);
 605                         netif_stop_queue(qca->net_dev);
 606                         netif_carrier_off(qca->net_dev);
 607                         qcaspi_flush_tx_ring(qca);
 608                         msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
 609                 }
 610
 611                 if (test_and_clear_bit(SPI_INTR, &qca->flags)) {
 612                         start_spi_intr_handling(qca, &intr_cause);
 613
 614                         if (intr_cause & SPI_INT_CPU_ON) {
 615                                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);
 616
 617                                 /* Frame decoding in progress */
 618                                 if (qca->frm_handle.state != qca->frm_handle.init)
 619                                         qca->net_dev->stats.rx_dropped++;
 620
 621                                 qcafrm_fsm_init_spi(&qca->frm_handle);
 622                                 qca->stats.device_reset++;
 623
 624                                 /* not synced. */
 625                                 if (qca->sync != QCASPI_SYNC_READY)
 626                                         continue;
 627
 628                                 netif_wake_queue(qca->net_dev);
 629                                 netif_carrier_on(qca->net_dev);
 630                         }
 631
 632                         if (intr_cause & SPI_INT_RDBUF_ERR) {
 633                                 /* restart sync */
 634                                 netdev_dbg(qca->net_dev, "===> rdbuf error!\n");
 635                                 qca->stats.read_buf_err++;
 636                                 set_bit(SPI_RESET, &qca->flags);
 637                                 continue;
 638                         }
 639
 640                         if (intr_cause & SPI_INT_WRBUF_ERR) {
 641                                 /* restart sync */
 642                                 netdev_dbg(qca->net_dev, "===> wrbuf error!\n");
 643                                 qca->stats.write_buf_err++;
 644                                 set_bit(SPI_RESET, &qca->flags);
 645                                 continue;
 646                         }
 647
 648                         /* can only handle other interrupts
 649                          * if sync has occurred
 650                          */
 651                         if (qca->sync == QCASPI_SYNC_READY) {
 652                                 if (intr_cause & SPI_INT_PKT_AVLBL)
 653                                         qcaspi_receive(qca);
 654                         }
 655
 656                         end_spi_intr_handling(qca, intr_cause);
 657                 }
 658
 659                 if (qca->sync == QCASPI_SYNC_READY)
 660                         qcaspi_transmit(qca);
 661         }
 662         set_current_state(TASK_RUNNING);
 663         netdev_info(qca->net_dev, "SPI thread exit\n");
 664
 665         return 0;
 666 }
 667
 668 static irqreturn_t
 669 qcaspi_intr_handler(int irq, void *data)
 670 {
 671         struct qcaspi *qca = data;
 672
 673         set_bit(SPI_INTR, &qca->flags);
 674         if (qca->spi_thread)
 675                 wake_up_process(qca->spi_thread);
 676
 677         return IRQ_HANDLED;
 678 }
 679
 680 static int
 681 qcaspi_netdev_open(struct net_device *dev)
 682 {
 683         struct qcaspi *qca = netdev_priv(dev);
 684         struct task_struct *thread;
 685
 686         if (!qca)
 687                 return -EINVAL;
 688
 689         set_bit(SPI_INTR, &qca->flags);
 690         qca->sync = QCASPI_SYNC_UNKNOWN;
 691         qcafrm_fsm_init_spi(&qca->frm_handle);
 692
 693         thread = kthread_run((void *)qcaspi_spi_thread,
 694                              qca, "%s", dev->name);
 695
 696         if (IS_ERR(thread)) {
 697                 netdev_err(dev, "%s: unable to start kernel thread.\n",
 698                            QCASPI_DRV_NAME);
 699                 return PTR_ERR(thread);
 700         }
 701
 702         qca->spi_thread = thread;
 703
 704         enable_irq(qca->spi_dev->irq);
 705
 706         /* SPI thread takes care of TX queue */
 707
 708         return 0;
 709 }
 710
 711 static int
 712 qcaspi_netdev_close(struct net_device *dev)
 713 {
 714         struct qcaspi *qca = netdev_priv(dev);
 715
 716         netif_stop_queue(dev);
 717
 718         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0, wr_verify);
 719         disable_irq(qca->spi_dev->irq);
 720
 721         if (qca->spi_thread) {
 722                 kthread_stop(qca->spi_thread);
 723                 qca->spi_thread = NULL;
 724         }
 725         qcaspi_flush_tx_ring(qca);
 726
 727         return 0;
 728 }
 729
 730 static netdev_tx_t
 731 qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
 732 {
 733         u32 frame_len;
 734         u8 *ptmp;
 735         struct qcaspi *qca = netdev_priv(dev);
 736         u16 new_tail;
 737         struct sk_buff *tskb;
 738         u8 pad_len = 0;
 739
 740         if (skb->len < QCAFRM_MIN_LEN)
 741                 pad_len = QCAFRM_MIN_LEN - skb->len;
 742
 743         if (qca->txr.skb[qca->txr.tail]) {
 744                 netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");
 745                 netif_stop_queue(qca->net_dev);
 746                 qca->stats.ring_full++;
 747                 return NETDEV_TX_BUSY;
 748         }
 749
 750         if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||
 751             (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {
 752                 tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,
 753                                        QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);
 754                 if (!tskb) {
 755                         qca->stats.out_of_mem++;
 756                         return NETDEV_TX_BUSY;
 757                 }
 758                 dev_kfree_skb(skb);
 759                 skb = tskb;
 760         }
 761
 762         frame_len = skb->len + pad_len;
 763
 764         ptmp = skb_push(skb, QCAFRM_HEADER_LEN);
 765         qcafrm_create_header(ptmp, frame_len);
 766
 767         if (pad_len) {
 768                 ptmp = skb_put_zero(skb, pad_len);
 769         }
 770
 771         ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);
 772         qcafrm_create_footer(ptmp);
 773
 774         netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",
 775                    skb->len);
 776
 777         qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;
 778
 779         new_tail = qca->txr.tail + 1;
 780         if (new_tail >= qca->txr.count)
 781                 new_tail = 0;
 782
 783         qca->txr.skb[qca->txr.tail] = skb;
 784         qca->txr.tail = new_tail;
 785
 786         if (!qcaspi_tx_ring_has_space(&qca->txr)) {
 787                 netif_stop_queue(qca->net_dev);
 788                 qca->stats.ring_full++;
 789         }
 790
 791         netif_trans_update(dev);
 792
 793         if (qca->spi_thread)
 794                 wake_up_process(qca->spi_thread);
 795
 796         return NETDEV_TX_OK;
 797 }
 798
 799 static void
 800 qcaspi_netdev_tx_timeout(struct net_device *dev, unsigned int txqueue)
 801 {
 802         struct qcaspi *qca = netdev_priv(dev);
 803
 804         netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
 805                     jiffies, jiffies - dev_trans_start(dev));
 806         qca->net_dev->stats.tx_errors++;
 807         /* Trigger tx queue flush and QCA7000 reset */
 808         set_bit(SPI_RESET, &qca->flags);
 809
 810         if (qca->spi_thread)
 811                 wake_up_process(qca->spi_thread);
 812 }
 813
 814 static int
 815 qcaspi_netdev_init(struct net_device *dev)
 816 {
 817         struct qcaspi *qca = netdev_priv(dev);
 818
 819         dev->mtu = QCAFRM_MAX_MTU;
 820         dev->type = ARPHRD_ETHER;
 821         qca->burst_len = qcaspi_burst_len;
 822         qca->spi_thread = NULL;
 823         qca->buffer_size = (QCAFRM_MAX_MTU + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +
 824                 QCAFRM_FOOTER_LEN + QCASPI_HW_PKT_LEN) * QCASPI_RX_MAX_FRAMES;
 825
 826         memset(&qca->stats, 0, sizeof(struct qcaspi_stats));
 827
 828         qca->rx_buffer = kmalloc(qca->buffer_size, GFP_KERNEL);
 829         if (!qca->rx_buffer)
 830                 return -ENOBUFS;
 831
 832         qca->rx_skb = netdev_alloc_skb_ip_align(dev, qca->net_dev->mtu +
 833                                                 VLAN_ETH_HLEN);
 834         if (!qca->rx_skb) {
 835                 kfree(qca->rx_buffer);
 836                 netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
 837                 return -ENOBUFS;
 838         }
 839
 840         return 0;
 841 }
 842
 843 static void
 844 qcaspi_netdev_uninit(struct net_device *dev)
 845 {
 846         struct qcaspi *qca = netdev_priv(dev);
 847
 848         kfree(qca->rx_buffer);
 849         qca->buffer_size = 0;
 850         dev_kfree_skb(qca->rx_skb);
 851 }
 852
 853 static const struct net_device_ops qcaspi_netdev_ops = {
 854         .ndo_init = qcaspi_netdev_init,
 855         .ndo_uninit = qcaspi_netdev_uninit,
 856         .ndo_open = qcaspi_netdev_open,
 857         .ndo_stop = qcaspi_netdev_close,
 858         .ndo_start_xmit = qcaspi_netdev_xmit,
 859         .ndo_set_mac_address = eth_mac_addr,
 860         .ndo_tx_timeout = qcaspi_netdev_tx_timeout,
 861         .ndo_validate_addr = eth_validate_addr,
 862 };
 863
 864 static void
 865 qcaspi_netdev_setup(struct net_device *dev)
 866 {
 867         struct qcaspi *qca = NULL;
 868
 869         dev->netdev_ops = &qcaspi_netdev_ops;
 870         qcaspi_set_ethtool_ops(dev);
 871         dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
 872         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 873         dev->needed_tailroom = ALIGN(QCAFRM_FOOTER_LEN + QCAFRM_MIN_LEN, 4);
 874         dev->needed_headroom = ALIGN(QCAFRM_HEADER_LEN, 4);
 875         dev->tx_queue_len = 100;
 876
 877         /* MTU range: 46 - 1500 */
 878         dev->min_mtu = QCAFRM_MIN_MTU;
 879         dev->max_mtu = QCAFRM_MAX_MTU;
 880
 881         qca = netdev_priv(dev);
 882         memset(qca, 0, sizeof(struct qcaspi));
 883
 884         memset(&qca->txr, 0, sizeof(qca->txr));
 885         qca->txr.count = QCASPI_TX_RING_MAX_LEN;
 886 }
 887
 888 static const struct of_device_id qca_spi_of_match[] = {
 889         { .compatible = "qca,qca7000" },
 890         { /* sentinel */ }
 891 };
 892 MODULE_DEVICE_TABLE(of, qca_spi_of_match);
 893
 894 static int
 895 qca_spi_probe(struct spi_device *spi)
 896 {
 897         struct qcaspi *qca = NULL;
 898         struct net_device *qcaspi_devs = NULL;
 899         u8 legacy_mode = 0;
 900         u16 signature;
 901         int ret;
 902
 903         if (!spi->dev.of_node) {
 904                 dev_err(&spi->dev, "Missing device tree\n");
 905                 return -EINVAL;
 906         }
 907
 908         legacy_mode = of_property_read_bool(spi->dev.of_node,
 909                                             "qca,legacy-mode");
 910
 911         if (qcaspi_clkspeed)
 912                 spi->max_speed_hz = qcaspi_clkspeed;
 913         else if (!spi->max_speed_hz)
 914                 spi->max_speed_hz = QCASPI_CLK_SPEED;
 915
 916         if (spi->max_speed_hz < QCASPI_CLK_SPEED_MIN ||
 917             spi->max_speed_hz > QCASPI_CLK_SPEED_MAX) {
 918                 dev_err(&spi->dev, "Invalid clkspeed: %u\n",
 919                         spi->max_speed_hz);
 920                 return -EINVAL;
 921         }
 922
 923         if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
 924             (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
 925                 dev_err(&spi->dev, "Invalid burst len: %d\n",
 926                         qcaspi_burst_len);
 927                 return -EINVAL;
 928         }
 929
 930         if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
 931             (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
 932                 dev_err(&spi->dev, "Invalid pluggable: %d\n",
 933                         qcaspi_pluggable);
 934                 return -EINVAL;
 935         }
 936
 937         if (wr_verify < QCASPI_WRITE_VERIFY_MIN ||
 938             wr_verify > QCASPI_WRITE_VERIFY_MAX) {
 939                 dev_err(&spi->dev, "Invalid write verify: %d\n",
 940                         wr_verify);
 941                 return -EINVAL;
 942         }
 943
 944         dev_info(&spi->dev, "ver=%s, clkspeed=%u, burst_len=%d, pluggable=%d\n",
 945                  QCASPI_DRV_VERSION,
 946                  spi->max_speed_hz,
 947                  qcaspi_burst_len,
 948                  qcaspi_pluggable);
 949
 950         spi->mode = SPI_MODE_3;
 951         if (spi_setup(spi) < 0) {
 952                 dev_err(&spi->dev, "Unable to setup SPI device\n");
 953                 return -EFAULT;
 954         }
 955
 956         qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
 957         if (!qcaspi_devs)
 958                 return -ENOMEM;
 959
 960         qcaspi_netdev_setup(qcaspi_devs);
 961         SET_NETDEV_DEV(qcaspi_devs, &spi->dev);
 962
 963         qca = netdev_priv(qcaspi_devs);
 964         if (!qca) {
 965                 free_netdev(qcaspi_devs);
 966                 dev_err(&spi->dev, "Fail to retrieve private structure\n");
 967                 return -ENOMEM;
 968         }
 969         qca->net_dev = qcaspi_devs;
 970         qca->spi_dev = spi;
 971         qca->legacy_mode = legacy_mode;
 972
 973         spi_set_drvdata(spi, qcaspi_devs);
 974
 975         ret = devm_request_irq(&spi->dev, spi->irq, qcaspi_intr_handler,
 976                                IRQF_NO_AUTOEN, qca->net_dev->name, qca);
 977         if (ret) {
 978                 dev_err(&spi->dev, "Unable to get IRQ %d (irqval=%d).\n",
 979                         spi->irq, ret);
 980                 free_netdev(qcaspi_devs);
 981                 return ret;
 982         }
 983
 984         ret = of_get_ethdev_address(spi->dev.of_node, qca->net_dev);
 985         if (ret) {
 986                 eth_hw_addr_random(qca->net_dev);
 987                 dev_info(&spi->dev, "Using random MAC address: %pM\n",
 988                          qca->net_dev->dev_addr);
 989         }
 990
 991         netif_carrier_off(qca->net_dev);
 992
 993         if (!qcaspi_pluggable) {
 994                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 995                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 996
 997                 if (signature != QCASPI_GOOD_SIGNATURE) {
 998                         dev_err(&spi->dev, "Invalid signature (expected 0x%04x, read 0x%04x)\n",
 999                                 QCASPI_GOOD_SIGNATURE, signature);
1000                         free_netdev(qcaspi_devs);
1001                         return -EFAULT;
1002                 }
1003         }
1004
1005         if (register_netdev(qcaspi_devs)) {
1006                 dev_err(&spi->dev, "Unable to register net device %s\n",
1007                         qcaspi_devs->name);
1008                 free_netdev(qcaspi_devs);
1009                 return -EFAULT;
1010         }
1011
1012         qcaspi_init_device_debugfs(qca);
1013
1014         return 0;
1015 }
1016
1017 static void
1018 qca_spi_remove(struct spi_device *spi)
1019 {
1020         struct net_device *qcaspi_devs = spi_get_drvdata(spi);
1021         struct qcaspi *qca = netdev_priv(qcaspi_devs);
1022
1023         qcaspi_remove_device_debugfs(qca);
1024
1025         unregister_netdev(qcaspi_devs);
1026         free_netdev(qcaspi_devs);
1027 }
1028
1029 static const struct spi_device_id qca_spi_id[] = {
1030         { "qca7000", 0 },
1031         { /* sentinel */ }
1032 };
1033 MODULE_DEVICE_TABLE(spi, qca_spi_id);
1034
1035 static struct spi_driver qca_spi_driver = {
1036         .driver = {
1037                 .name   = QCASPI_DRV_NAME,
1038                 .of_match_table = qca_spi_of_match,
1039         },
1040         .id_table = qca_spi_id,
1041         .probe    = qca_spi_probe,
1042         .remove   = qca_spi_remove,
1043 };
1044 module_spi_driver(qca_spi_driver);
1045
1046 MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 SPI Driver");
1047 MODULE_AUTHOR("Qualcomm Atheros Communications");
1048 MODULE_AUTHOR("Stefan Wahren <[email protected]>");
1049 MODULE_LICENSE("Dual BSD/GPL");
1050 MODULE_VERSION(QCASPI_DRV_VERSION);