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