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 = &qca->spi_msg2;
 103         struct spi_transfer *transfer = &qca->spi_xfer2[0];
 104         int ret;
 105
 106         cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 107         transfer->tx_buf = &cmd;
 108         transfer->rx_buf = NULL;
 109         transfer->len = QCASPI_CMD_LEN;
 110         transfer = &qca->spi_xfer2[1];
 111         transfer->tx_buf = src;
 112         transfer->rx_buf = NULL;
 113         transfer->len = len;
 114
 115         ret = spi_sync(qca->spi_dev, msg);
 116
 117         if (ret || (msg->actual_length != QCASPI_CMD_LEN + len)) {
 118                 qcaspi_spi_error(qca);
 119                 return 0;
 120         }
 121
 122         return len;
 123 }
 124
 125 static u32
 126 qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)
 127 {
 128         struct spi_message *msg = &qca->spi_msg1;
 129         struct spi_transfer *transfer = &qca->spi_xfer1;
 130         int ret;
 131
 132         transfer->tx_buf = src;
 133         transfer->rx_buf = NULL;
 134         transfer->len = len;
 135
 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 = &qca->spi_msg2;
 150         __be16 cmd;
 151         struct spi_transfer *transfer = &qca->spi_xfer2[0];
 152         int ret;
 153
 154         cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 155         transfer->tx_buf = &cmd;
 156         transfer->rx_buf = NULL;
 157         transfer->len = QCASPI_CMD_LEN;
 158         transfer = &qca->spi_xfer2[1];
 159         transfer->tx_buf = NULL;
 160         transfer->rx_buf = dst;
 161         transfer->len = len;
 162
 163         ret = spi_sync(qca->spi_dev, msg);
 164
 165         if (ret || (msg->actual_length != QCASPI_CMD_LEN + len)) {
 166                 qcaspi_spi_error(qca);
 167                 return 0;
 168         }
 169
 170         return len;
 171 }
 172
 173 static u32
 174 qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)
 175 {
 176         struct spi_message *msg = &qca->spi_msg1;
 177         struct spi_transfer *transfer = &qca->spi_xfer1;
 178         int ret;
 179
 180         transfer->tx_buf = NULL;
 181         transfer->rx_buf = dst;
 182         transfer->len = len;
 183
 184         ret = spi_sync(qca->spi_dev, msg);
 185
 186         if (ret || (msg->actual_length != len)) {
 187                 qcaspi_spi_error(qca);
 188                 return 0;
 189         }
 190
 191         return len;
 192 }
 193
 194 static int
 195 qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd)
 196 {
 197         __be16 tx_data;
 198         struct spi_message *msg = &qca->spi_msg1;
 199         struct spi_transfer *transfer = &qca->spi_xfer1;
 200         int ret;
 201
 202         tx_data = cpu_to_be16(cmd);
 203         transfer->len = sizeof(tx_data);
 204         transfer->tx_buf = &tx_data;
 205         transfer->rx_buf = NULL;
 206
 207         ret = spi_sync(qca->spi_dev, msg);
 208
 209         if (!ret)
 210                 ret = msg->status;
 211
 212         if (ret)
 213                 qcaspi_spi_error(qca);
 214
 215         return ret;
 216 }
 217
 218 static int
 219 qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
 220 {
 221         u32 count;
 222         u32 written;
 223         u32 offset;
 224         u32 len;
 225
 226         len = skb->len;
 227
 228         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len);
 229         if (qca->legacy_mode)
 230                 qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
 231
 232         offset = 0;
 233         while (len) {
 234                 count = len;
 235                 if (count > qca->burst_len)
 236                         count = qca->burst_len;
 237
 238                 if (qca->legacy_mode) {
 239                         written = qcaspi_write_legacy(qca,
 240                                                       skb->data + offset,
 241                                                       count);
 242                 } else {
 243                         written = qcaspi_write_burst(qca,
 244                                                      skb->data + offset,
 245                                                      count);
 246                 }
 247
 248                 if (written != count)
 249                         return -1;
 250
 251                 offset += count;
 252                 len -= count;
 253         }
 254
 255         return 0;
 256 }
 257
 258 static int
 259 qcaspi_transmit(struct qcaspi *qca)
 260 {
 261         struct net_device_stats *n_stats = &qca->net_dev->stats;
 262         u16 available = 0;
 263         u32 pkt_len;
 264         u16 new_head;
 265         u16 packets = 0;
 266
 267         if (qca->txr.skb[qca->txr.head] == NULL)
 268                 return 0;
 269
 270         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, &available);
 271
 272         while (qca->txr.skb[qca->txr.head]) {
 273                 pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;
 274
 275                 if (available < pkt_len) {
 276                         if (packets == 0)
 277                                 qca->stats.write_buf_miss++;
 278                         break;
 279                 }
 280
 281                 if (qcaspi_tx_frame(qca, qca->txr.skb[qca->txr.head]) == -1) {
 282                         qca->stats.write_err++;
 283                         return -1;
 284                 }
 285
 286                 packets++;
 287                 n_stats->tx_packets++;
 288                 n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;
 289                 available -= pkt_len;
 290
 291                 /* remove the skb from the queue */
 292                 /* XXX After inconsistent lock states netif_tx_lock()
 293                  * has been replaced by netif_tx_lock_bh() and so on.
 294                  */
 295                 netif_tx_lock_bh(qca->net_dev);
 296                 dev_kfree_skb(qca->txr.skb[qca->txr.head]);
 297                 qca->txr.skb[qca->txr.head] = NULL;
 298                 qca->txr.size -= pkt_len;
 299                 new_head = qca->txr.head + 1;
 300                 if (new_head >= qca->txr.count)
 301                         new_head = 0;
 302                 qca->txr.head = new_head;
 303                 if (netif_queue_stopped(qca->net_dev))
 304                         netif_wake_queue(qca->net_dev);
 305                 netif_tx_unlock_bh(qca->net_dev);
 306         }
 307
 308         return 0;
 309 }
 310
 311 static int
 312 qcaspi_receive(struct qcaspi *qca)
 313 {
 314         struct net_device *net_dev = qca->net_dev;
 315         struct net_device_stats *n_stats = &net_dev->stats;
 316         u16 available = 0;
 317         u32 bytes_read;
 318         u8 *cp;
 319
 320         /* Allocate rx SKB if we don't have one available. */
 321         if (!qca->rx_skb) {
 322                 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
 323                                                         net_dev->mtu +
 324                                                         VLAN_ETH_HLEN);
 325                 if (!qca->rx_skb) {
 326                         netdev_dbg(net_dev, "out of RX resources\n");
 327                         qca->stats.out_of_mem++;
 328                         return -1;
 329                 }
 330         }
 331
 332         /* Read the packet size. */
 333         qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);
 334         netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %08x\n",
 335                    available);
 336
 337         if (available == 0) {
 338                 netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");
 339                 return -1;
 340         }
 341
 342         qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available);
 343
 344         if (qca->legacy_mode)
 345                 qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
 346
 347         while (available) {
 348                 u32 count = available;
 349
 350                 if (count > qca->burst_len)
 351                         count = qca->burst_len;
 352
 353                 if (qca->legacy_mode) {
 354                         bytes_read = qcaspi_read_legacy(qca, qca->rx_buffer,
 355                                                         count);
 356                 } else {
 357                         bytes_read = qcaspi_read_burst(qca, qca->rx_buffer,
 358                                                        count);
 359                 }
 360
 361                 netdev_dbg(net_dev, "available: %d, byte read: %d\n",
 362                            available, bytes_read);
 363
 364                 if (bytes_read) {
 365                         available -= bytes_read;
 366                 } else {
 367                         qca->stats.read_err++;
 368                         return -1;
 369                 }
 370
 371                 cp = qca->rx_buffer;
 372
 373                 while ((bytes_read--) && (qca->rx_skb)) {
 374                         s32 retcode;
 375
 376                         retcode = qcafrm_fsm_decode(&qca->frm_handle,
 377                                                     qca->rx_skb->data,
 378                                                     skb_tailroom(qca->rx_skb),
 379                                                     *cp);
 380                         cp++;
 381                         switch (retcode) {
 382                         case QCAFRM_GATHER:
 383                         case QCAFRM_NOHEAD:
 384                                 break;
 385                         case QCAFRM_NOTAIL:
 386                                 netdev_dbg(net_dev, "no RX tail\n");
 387                                 n_stats->rx_errors++;
 388                                 n_stats->rx_dropped++;
 389                                 break;
 390                         case QCAFRM_INVLEN:
 391                                 netdev_dbg(net_dev, "invalid RX length\n");
 392                                 n_stats->rx_errors++;
 393                                 n_stats->rx_dropped++;
 394                                 break;
 395                         default:
 396                                 qca->rx_skb->dev = qca->net_dev;
 397                                 n_stats->rx_packets++;
 398                                 n_stats->rx_bytes += retcode;
 399                                 skb_put(qca->rx_skb, retcode);
 400                                 qca->rx_skb->protocol = eth_type_trans(
 401                                         qca->rx_skb, qca->rx_skb->dev);
 402                                 qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
 403                                 netif_rx_ni(qca->rx_skb);
 404                                 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
 405                                         net_dev->mtu + VLAN_ETH_HLEN);
 406                                 if (!qca->rx_skb) {
 407                                         netdev_dbg(net_dev, "out of RX resources\n");
 408                                         n_stats->rx_errors++;
 409                                         qca->stats.out_of_mem++;
 410                                         break;
 411                                 }
 412                         }
 413                 }
 414         }
 415
 416         return 0;
 417 }
 418
 419 /*   Check that tx ring stores only so much bytes
 420  *   that fit into the internal QCA buffer.
 421  */
 422
 423 static int
 424 qcaspi_tx_ring_has_space(struct tx_ring *txr)
 425 {
 426         if (txr->skb[txr->tail])
 427                 return 0;
 428
 429         return (txr->size + QCAFRM_MAX_LEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
 430 }
 431
 432 /*   Flush the tx ring. This function is only safe to
 433  *   call from the qcaspi_spi_thread.
 434  */
 435
 436 static void
 437 qcaspi_flush_tx_ring(struct qcaspi *qca)
 438 {
 439         int i;
 440
 441         /* XXX After inconsistent lock states netif_tx_lock()
 442          * has been replaced by netif_tx_lock_bh() and so on.
 443          */
 444         netif_tx_lock_bh(qca->net_dev);
 445         for (i = 0; i < TX_RING_MAX_LEN; i++) {
 446                 if (qca->txr.skb[i]) {
 447                         dev_kfree_skb(qca->txr.skb[i]);
 448                         qca->txr.skb[i] = NULL;
 449                         qca->net_dev->stats.tx_dropped++;
 450                 }
 451         }
 452         qca->txr.tail = 0;
 453         qca->txr.head = 0;
 454         qca->txr.size = 0;
 455         netif_tx_unlock_bh(qca->net_dev);
 456 }
 457
 458 static void
 459 qcaspi_qca7k_sync(struct qcaspi *qca, int event)
 460 {
 461         u16 signature = 0;
 462         u16 spi_config;
 463         u16 wrbuf_space = 0;
 464         static u16 reset_count;
 465
 466         if (event == QCASPI_EVENT_CPUON) {
 467                 /* Read signature twice, if not valid
 468                  * go back to unknown state.
 469                  */
 470                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 471                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 472                 if (signature != QCASPI_GOOD_SIGNATURE) {
 473                         qca->sync = QCASPI_SYNC_UNKNOWN;
 474                         netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");
 475                 } else {
 476                         /* ensure that the WRBUF is empty */
 477                         qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,
 478                                              &wrbuf_space);
 479                         if (wrbuf_space != QCASPI_HW_BUF_LEN) {
 480                                 netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");
 481                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 482                         } else {
 483                                 netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");
 484                                 qca->sync = QCASPI_SYNC_READY;
 485                                 return;
 486                         }
 487                 }
 488         }
 489
 490         switch (qca->sync) {
 491         case QCASPI_SYNC_READY:
 492                 /* Read signature, if not valid go to unknown state. */
 493                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 494                 if (signature != QCASPI_GOOD_SIGNATURE) {
 495                         qca->sync = QCASPI_SYNC_UNKNOWN;
 496                         netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");
 497                         /* don't reset right away */
 498                         return;
 499                 }
 500                 break;
 501         case QCASPI_SYNC_UNKNOWN:
 502                 /* Read signature, if not valid stay in unknown state */
 503                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 504                 if (signature != QCASPI_GOOD_SIGNATURE) {
 505                         netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");
 506                         return;
 507                 }
 508
 509                 /* TODO: use GPIO to reset QCA7000 in legacy mode*/
 510                 netdev_dbg(qca->net_dev, "sync: resetting device.\n");
 511                 qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);
 512                 spi_config |= QCASPI_SLAVE_RESET_BIT;
 513                 qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config);
 514
 515                 qca->sync = QCASPI_SYNC_RESET;
 516                 qca->stats.trig_reset++;
 517                 reset_count = 0;
 518                 break;
 519         case QCASPI_SYNC_RESET:
 520                 reset_count++;
 521                 netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",
 522                            reset_count);
 523                 if (reset_count >= QCASPI_RESET_TIMEOUT) {
 524                         /* reset did not seem to take place, try again */
 525                         qca->sync = QCASPI_SYNC_UNKNOWN;
 526                         qca->stats.reset_timeout++;
 527                         netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");
 528                 }
 529                 break;
 530         }
 531 }
 532
 533 static int
 534 qcaspi_spi_thread(void *data)
 535 {
 536         struct qcaspi *qca = data;
 537         u16 intr_cause = 0;
 538
 539         netdev_info(qca->net_dev, "SPI thread created\n");
 540         while (!kthread_should_stop()) {
 541                 set_current_state(TASK_INTERRUPTIBLE);
 542                 if ((qca->intr_req == qca->intr_svc) &&
 543                     (qca->txr.skb[qca->txr.head] == NULL) &&
 544                     (qca->sync == QCASPI_SYNC_READY))
 545                         schedule();
 546
 547                 set_current_state(TASK_RUNNING);
 548
 549                 netdev_dbg(qca->net_dev, "have work to do. int: %d, tx_skb: %p\n",
 550                            qca->intr_req - qca->intr_svc,
 551                            qca->txr.skb[qca->txr.head]);
 552
 553                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
 554
 555                 if (qca->sync != QCASPI_SYNC_READY) {
 556                         netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",
 557                                    (unsigned int)qca->sync);
 558                         netif_stop_queue(qca->net_dev);
 559                         netif_carrier_off(qca->net_dev);
 560                         qcaspi_flush_tx_ring(qca);
 561                         msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
 562                 }
 563
 564                 if (qca->intr_svc != qca->intr_req) {
 565                         qca->intr_svc = qca->intr_req;
 566                         start_spi_intr_handling(qca, &intr_cause);
 567
 568                         if (intr_cause & SPI_INT_CPU_ON) {
 569                                 qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);
 570
 571                                 /* not synced. */
 572                                 if (qca->sync != QCASPI_SYNC_READY)
 573                                         continue;
 574
 575                                 qca->stats.device_reset++;
 576                                 netif_wake_queue(qca->net_dev);
 577                                 netif_carrier_on(qca->net_dev);
 578                         }
 579
 580                         if (intr_cause & SPI_INT_RDBUF_ERR) {
 581                                 /* restart sync */
 582                                 netdev_dbg(qca->net_dev, "===> rdbuf error!\n");
 583                                 qca->stats.read_buf_err++;
 584                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 585                                 continue;
 586                         }
 587
 588                         if (intr_cause & SPI_INT_WRBUF_ERR) {
 589                                 /* restart sync */
 590                                 netdev_dbg(qca->net_dev, "===> wrbuf error!\n");
 591                                 qca->stats.write_buf_err++;
 592                                 qca->sync = QCASPI_SYNC_UNKNOWN;
 593                                 continue;
 594                         }
 595
 596                         /* can only handle other interrupts
 597                          * if sync has occurred
 598                          */
 599                         if (qca->sync == QCASPI_SYNC_READY) {
 600                                 if (intr_cause & SPI_INT_PKT_AVLBL)
 601                                         qcaspi_receive(qca);
 602                         }
 603
 604                         end_spi_intr_handling(qca, intr_cause);
 605                 }
 606
 607                 if (qca->sync == QCASPI_SYNC_READY)
 608                         qcaspi_transmit(qca);
 609         }
 610         set_current_state(TASK_RUNNING);
 611         netdev_info(qca->net_dev, "SPI thread exit\n");
 612
 613         return 0;
 614 }
 615
 616 static irqreturn_t
 617 qcaspi_intr_handler(int irq, void *data)
 618 {
 619         struct qcaspi *qca = data;
 620
 621         qca->intr_req++;
 622         if (qca->spi_thread &&
 623             qca->spi_thread->state != TASK_RUNNING)
 624                 wake_up_process(qca->spi_thread);
 625
 626         return IRQ_HANDLED;
 627 }
 628
 629 static int
 630 qcaspi_netdev_open(struct net_device *dev)
 631 {
 632         struct qcaspi *qca = netdev_priv(dev);
 633         int ret = 0;
 634
 635         if (!qca)
 636                 return -EINVAL;
 637
 638         qca->intr_req = 1;
 639         qca->intr_svc = 0;
 640         qca->sync = QCASPI_SYNC_UNKNOWN;
 641         qcafrm_fsm_init_spi(&qca->frm_handle);
 642
 643         qca->spi_thread = kthread_run((void *)qcaspi_spi_thread,
 644                                       qca, "%s", dev->name);
 645
 646         if (IS_ERR(qca->spi_thread)) {
 647                 netdev_err(dev, "%s: unable to start kernel thread.\n",
 648                            QCASPI_DRV_NAME);
 649                 return PTR_ERR(qca->spi_thread);
 650         }
 651
 652         ret = request_irq(qca->spi_dev->irq, qcaspi_intr_handler, 0,
 653                           dev->name, qca);
 654         if (ret) {
 655                 netdev_err(dev, "%s: unable to get IRQ %d (irqval=%d).\n",
 656                            QCASPI_DRV_NAME, qca->spi_dev->irq, ret);
 657                 kthread_stop(qca->spi_thread);
 658                 return ret;
 659         }
 660
 661         /* SPI thread takes care of TX queue */
 662
 663         return 0;
 664 }
 665
 666 static int
 667 qcaspi_netdev_close(struct net_device *dev)
 668 {
 669         struct qcaspi *qca = netdev_priv(dev);
 670
 671         netif_stop_queue(dev);
 672
 673         qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
 674         free_irq(qca->spi_dev->irq, qca);
 675
 676         kthread_stop(qca->spi_thread);
 677         qca->spi_thread = NULL;
 678         qcaspi_flush_tx_ring(qca);
 679
 680         return 0;
 681 }
 682
 683 static netdev_tx_t
 684 qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
 685 {
 686         u32 frame_len;
 687         u8 *ptmp;
 688         struct qcaspi *qca = netdev_priv(dev);
 689         u16 new_tail;
 690         struct sk_buff *tskb;
 691         u8 pad_len = 0;
 692
 693         if (skb->len < QCAFRM_MIN_LEN)
 694                 pad_len = QCAFRM_MIN_LEN - skb->len;
 695
 696         if (qca->txr.skb[qca->txr.tail]) {
 697                 netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");
 698                 netif_stop_queue(qca->net_dev);
 699                 qca->stats.ring_full++;
 700                 return NETDEV_TX_BUSY;
 701         }
 702
 703         if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||
 704             (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {
 705                 tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,
 706                                        QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);
 707                 if (!tskb) {
 708                         qca->stats.out_of_mem++;
 709                         return NETDEV_TX_BUSY;
 710                 }
 711                 dev_kfree_skb(skb);
 712                 skb = tskb;
 713         }
 714
 715         frame_len = skb->len + pad_len;
 716
 717         ptmp = skb_push(skb, QCAFRM_HEADER_LEN);
 718         qcafrm_create_header(ptmp, frame_len);
 719
 720         if (pad_len) {
 721                 ptmp = skb_put_zero(skb, pad_len);
 722         }
 723
 724         ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);
 725         qcafrm_create_footer(ptmp);
 726
 727         netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",
 728                    skb->len);
 729
 730         qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;
 731
 732         new_tail = qca->txr.tail + 1;
 733         if (new_tail >= qca->txr.count)
 734                 new_tail = 0;
 735
 736         qca->txr.skb[qca->txr.tail] = skb;
 737         qca->txr.tail = new_tail;
 738
 739         if (!qcaspi_tx_ring_has_space(&qca->txr)) {
 740                 netif_stop_queue(qca->net_dev);
 741                 qca->stats.ring_full++;
 742         }
 743
 744         netif_trans_update(dev);
 745
 746         if (qca->spi_thread &&
 747             qca->spi_thread->state != TASK_RUNNING)
 748                 wake_up_process(qca->spi_thread);
 749
 750         return NETDEV_TX_OK;
 751 }
 752
 753 static void
 754 qcaspi_netdev_tx_timeout(struct net_device *dev)
 755 {
 756         struct qcaspi *qca = netdev_priv(dev);
 757
 758         netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
 759                     jiffies, jiffies - dev_trans_start(dev));
 760         qca->net_dev->stats.tx_errors++;
 761         /* Trigger tx queue flush and QCA7000 reset */
 762         qca->sync = QCASPI_SYNC_UNKNOWN;
 763
 764         if (qca->spi_thread)
 765                 wake_up_process(qca->spi_thread);
 766 }
 767
 768 static int
 769 qcaspi_netdev_init(struct net_device *dev)
 770 {
 771         struct qcaspi *qca = netdev_priv(dev);
 772
 773         dev->mtu = QCAFRM_MAX_MTU;
 774         dev->type = ARPHRD_ETHER;
 775         qca->clkspeed = qcaspi_clkspeed;
 776         qca->burst_len = qcaspi_burst_len;
 777         qca->spi_thread = NULL;
 778         qca->buffer_size = (dev->mtu + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +
 779                 QCAFRM_FOOTER_LEN + 4) * 4;
 780
 781         memset(&qca->stats, 0, sizeof(struct qcaspi_stats));
 782
 783         qca->rx_buffer = kmalloc(qca->buffer_size, GFP_KERNEL);
 784         if (!qca->rx_buffer)
 785                 return -ENOBUFS;
 786
 787         qca->rx_skb = netdev_alloc_skb_ip_align(dev, qca->net_dev->mtu +
 788                                                 VLAN_ETH_HLEN);
 789         if (!qca->rx_skb) {
 790                 kfree(qca->rx_buffer);
 791                 netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
 792                 return -ENOBUFS;
 793         }
 794
 795         return 0;
 796 }
 797
 798 static void
 799 qcaspi_netdev_uninit(struct net_device *dev)
 800 {
 801         struct qcaspi *qca = netdev_priv(dev);
 802
 803         kfree(qca->rx_buffer);
 804         qca->buffer_size = 0;
 805         if (qca->rx_skb)
 806                 dev_kfree_skb(qca->rx_skb);
 807 }
 808
 809 static const struct net_device_ops qcaspi_netdev_ops = {
 810         .ndo_init = qcaspi_netdev_init,
 811         .ndo_uninit = qcaspi_netdev_uninit,
 812         .ndo_open = qcaspi_netdev_open,
 813         .ndo_stop = qcaspi_netdev_close,
 814         .ndo_start_xmit = qcaspi_netdev_xmit,
 815         .ndo_set_mac_address = eth_mac_addr,
 816         .ndo_tx_timeout = qcaspi_netdev_tx_timeout,
 817         .ndo_validate_addr = eth_validate_addr,
 818 };
 819
 820 static void
 821 qcaspi_netdev_setup(struct net_device *dev)
 822 {
 823         struct qcaspi *qca = NULL;
 824
 825         dev->netdev_ops = &qcaspi_netdev_ops;
 826         qcaspi_set_ethtool_ops(dev);
 827         dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
 828         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 829         dev->tx_queue_len = 100;
 830
 831         /* MTU range: 46 - 1500 */
 832         dev->min_mtu = QCAFRM_MIN_MTU;
 833         dev->max_mtu = QCAFRM_MAX_MTU;
 834
 835         qca = netdev_priv(dev);
 836         memset(qca, 0, sizeof(struct qcaspi));
 837
 838         memset(&qca->spi_xfer1, 0, sizeof(struct spi_transfer));
 839         memset(&qca->spi_xfer2, 0, sizeof(struct spi_transfer) * 2);
 840
 841         spi_message_init(&qca->spi_msg1);
 842         spi_message_add_tail(&qca->spi_xfer1, &qca->spi_msg1);
 843
 844         spi_message_init(&qca->spi_msg2);
 845         spi_message_add_tail(&qca->spi_xfer2[0], &qca->spi_msg2);
 846         spi_message_add_tail(&qca->spi_xfer2[1], &qca->spi_msg2);
 847
 848         memset(&qca->txr, 0, sizeof(qca->txr));
 849         qca->txr.count = TX_RING_MAX_LEN;
 850 }
 851
 852 static const struct of_device_id qca_spi_of_match[] = {
 853         { .compatible = "qca,qca7000" },
 854         { /* sentinel */ }
 855 };
 856 MODULE_DEVICE_TABLE(of, qca_spi_of_match);
 857
 858 static int
 859 qca_spi_probe(struct spi_device *spi)
 860 {
 861         struct qcaspi *qca = NULL;
 862         struct net_device *qcaspi_devs = NULL;
 863         u8 legacy_mode = 0;
 864         u16 signature;
 865         const char *mac;
 866
 867         if (!spi->dev.of_node) {
 868                 dev_err(&spi->dev, "Missing device tree\n");
 869                 return -EINVAL;
 870         }
 871
 872         legacy_mode = of_property_read_bool(spi->dev.of_node,
 873                                             "qca,legacy-mode");
 874
 875         if (qcaspi_clkspeed == 0) {
 876                 if (spi->max_speed_hz)
 877                         qcaspi_clkspeed = spi->max_speed_hz;
 878                 else
 879                         qcaspi_clkspeed = QCASPI_CLK_SPEED;
 880         }
 881
 882         if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
 883             (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
 884                 dev_err(&spi->dev, "Invalid clkspeed: %d\n",
 885                         qcaspi_clkspeed);
 886                 return -EINVAL;
 887         }
 888
 889         if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
 890             (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
 891                 dev_err(&spi->dev, "Invalid burst len: %d\n",
 892                         qcaspi_burst_len);
 893                 return -EINVAL;
 894         }
 895
 896         if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
 897             (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
 898                 dev_err(&spi->dev, "Invalid pluggable: %d\n",
 899                         qcaspi_pluggable);
 900                 return -EINVAL;
 901         }
 902
 903         dev_info(&spi->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
 904                  QCASPI_DRV_VERSION,
 905                  qcaspi_clkspeed,
 906                  qcaspi_burst_len,
 907                  qcaspi_pluggable);
 908
 909         spi->mode = SPI_MODE_3;
 910         spi->max_speed_hz = qcaspi_clkspeed;
 911         if (spi_setup(spi) < 0) {
 912                 dev_err(&spi->dev, "Unable to setup SPI device\n");
 913                 return -EFAULT;
 914         }
 915
 916         qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
 917         if (!qcaspi_devs)
 918                 return -ENOMEM;
 919
 920         qcaspi_netdev_setup(qcaspi_devs);
 921         SET_NETDEV_DEV(qcaspi_devs, &spi->dev);
 922
 923         qca = netdev_priv(qcaspi_devs);
 924         if (!qca) {
 925                 free_netdev(qcaspi_devs);
 926                 dev_err(&spi->dev, "Fail to retrieve private structure\n");
 927                 return -ENOMEM;
 928         }
 929         qca->net_dev = qcaspi_devs;
 930         qca->spi_dev = spi;
 931         qca->legacy_mode = legacy_mode;
 932
 933         spi_set_drvdata(spi, qcaspi_devs);
 934
 935         mac = of_get_mac_address(spi->dev.of_node);
 936
 937         if (mac)
 938                 ether_addr_copy(qca->net_dev->dev_addr, mac);
 939
 940         if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
 941                 eth_hw_addr_random(qca->net_dev);
 942                 dev_info(&spi->dev, "Using random MAC address: %pM\n",
 943                          qca->net_dev->dev_addr);
 944         }
 945
 946         netif_carrier_off(qca->net_dev);
 947
 948         if (!qcaspi_pluggable) {
 949                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 950                 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 951
 952                 if (signature != QCASPI_GOOD_SIGNATURE) {
 953                         dev_err(&spi->dev, "Invalid signature (0x%04X)\n",
 954                                 signature);
 955                         free_netdev(qcaspi_devs);
 956                         return -EFAULT;
 957                 }
 958         }
 959
 960         if (register_netdev(qcaspi_devs)) {
 961                 dev_err(&spi->dev, "Unable to register net device %s\n",
 962                         qcaspi_devs->name);
 963                 free_netdev(qcaspi_devs);
 964                 return -EFAULT;
 965         }
 966
 967         qcaspi_init_device_debugfs(qca);
 968
 969         return 0;
 970 }
 971
 972 static int
 973 qca_spi_remove(struct spi_device *spi)
 974 {
 975         struct net_device *qcaspi_devs = spi_get_drvdata(spi);
 976         struct qcaspi *qca = netdev_priv(qcaspi_devs);
 977
 978         qcaspi_remove_device_debugfs(qca);
 979
 980         unregister_netdev(qcaspi_devs);
 981         free_netdev(qcaspi_devs);
 982
 983         return 0;
 984 }
 985
 986 static const struct spi_device_id qca_spi_id[] = {
 987         { "qca7000", 0 },
 988         { /* sentinel */ }
 989 };
 990 MODULE_DEVICE_TABLE(spi, qca_spi_id);
 991
 992 static struct spi_driver qca_spi_driver = {
 993         .driver = {
 994                 .name   = QCASPI_DRV_NAME,
 995                 .of_match_table = qca_spi_of_match,
 996         },
 997         .id_table = qca_spi_id,
 998         .probe    = qca_spi_probe,
 999         .remove   = qca_spi_remove,
1000 };
1001 module_spi_driver(qca_spi_driver);
1002
1003 MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 SPI Driver");
1004 MODULE_AUTHOR("Qualcomm Atheros Communications");
1005 MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
1006 MODULE_LICENSE("Dual BSD/GPL");
1007 MODULE_VERSION(QCASPI_DRV_VERSION);