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   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
  56static int qcaspi_clkspeed;
  57module_param(qcaspi_clkspeed, int, 0);
  58MODULE_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
  62static int qcaspi_burst_len = MAX_DMA_BURST_LEN;
  63module_param(qcaspi_burst_len, int, 0);
  64MODULE_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
  68static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;
  69module_param(qcaspi_pluggable, int, 0);
  70MODULE_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
  75static void
  76start_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
  85static void
  86end_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
  98static u32
  99qcaspi_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
 125static u32
 126qcaspi_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
 146static u32
 147qcaspi_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
 173static u32
 174qcaspi_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
 194static int
 195qcaspi_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
 218static int
 219qcaspi_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
 258static int
 259qcaspi_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
 311static int
 312qcaspi_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
 423static int
 424qcaspi_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
 436static void
 437qcaspi_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
 458static void
 459qcaspi_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
 533static int
 534qcaspi_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
 616static irqreturn_t
 617qcaspi_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
 629static int
 630qcaspi_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	netif_start_queue(qca->net_dev);
 662
 663	return 0;
 664}
 665
 666static int
 667qcaspi_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
 683static netdev_tx_t
 684qcaspi_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
 753static void
 754qcaspi_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
 765static int
 766qcaspi_netdev_init(struct net_device *dev)
 767{
 768	struct qcaspi *qca = netdev_priv(dev);
 769
 770	dev->mtu = QCAFRM_MAX_MTU;
 771	dev->type = ARPHRD_ETHER;
 772	qca->clkspeed = qcaspi_clkspeed;
 773	qca->burst_len = qcaspi_burst_len;
 774	qca->spi_thread = NULL;
 775	qca->buffer_size = (dev->mtu + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +
 776		QCAFRM_FOOTER_LEN + 4) * 4;
 777
 778	memset(&qca->stats, 0, sizeof(struct qcaspi_stats));
 779
 780	qca->rx_buffer = kmalloc(qca->buffer_size, GFP_KERNEL);
 781	if (!qca->rx_buffer)
 782		return -ENOBUFS;
 783
 784	qca->rx_skb = netdev_alloc_skb_ip_align(dev, qca->net_dev->mtu +
 785						VLAN_ETH_HLEN);
 786	if (!qca->rx_skb) {
 787		kfree(qca->rx_buffer);
 788		netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
 789		return -ENOBUFS;
 790	}
 791
 792	return 0;
 793}
 794
 795static void
 796qcaspi_netdev_uninit(struct net_device *dev)
 797{
 798	struct qcaspi *qca = netdev_priv(dev);
 799
 800	kfree(qca->rx_buffer);
 801	qca->buffer_size = 0;
 802	if (qca->rx_skb)
 803		dev_kfree_skb(qca->rx_skb);
 804}
 805
 806static const struct net_device_ops qcaspi_netdev_ops = {
 807	.ndo_init = qcaspi_netdev_init,
 808	.ndo_uninit = qcaspi_netdev_uninit,
 809	.ndo_open = qcaspi_netdev_open,
 810	.ndo_stop = qcaspi_netdev_close,
 811	.ndo_start_xmit = qcaspi_netdev_xmit,
 812	.ndo_set_mac_address = eth_mac_addr,
 813	.ndo_tx_timeout = qcaspi_netdev_tx_timeout,
 814	.ndo_validate_addr = eth_validate_addr,
 815};
 816
 817static void
 818qcaspi_netdev_setup(struct net_device *dev)
 819{
 820	struct qcaspi *qca = NULL;
 821
 822	dev->netdev_ops = &qcaspi_netdev_ops;
 823	qcaspi_set_ethtool_ops(dev);
 824	dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
 825	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 826	dev->tx_queue_len = 100;
 827
 828	/* MTU range: 46 - 1500 */
 829	dev->min_mtu = QCAFRM_MIN_MTU;
 830	dev->max_mtu = QCAFRM_MAX_MTU;
 831
 832	qca = netdev_priv(dev);
 833	memset(qca, 0, sizeof(struct qcaspi));
 834
 835	memset(&qca->spi_xfer1, 0, sizeof(struct spi_transfer));
 836	memset(&qca->spi_xfer2, 0, sizeof(struct spi_transfer) * 2);
 837
 838	spi_message_init(&qca->spi_msg1);
 839	spi_message_add_tail(&qca->spi_xfer1, &qca->spi_msg1);
 840
 841	spi_message_init(&qca->spi_msg2);
 842	spi_message_add_tail(&qca->spi_xfer2[0], &qca->spi_msg2);
 843	spi_message_add_tail(&qca->spi_xfer2[1], &qca->spi_msg2);
 844
 845	memset(&qca->txr, 0, sizeof(qca->txr));
 846	qca->txr.count = TX_RING_MAX_LEN;
 847}
 848
 849static const struct of_device_id qca_spi_of_match[] = {
 850	{ .compatible = "qca,qca7000" },
 851	{ /* sentinel */ }
 852};
 853MODULE_DEVICE_TABLE(of, qca_spi_of_match);
 854
 855static int
 856qca_spi_probe(struct spi_device *spi)
 857{
 858	struct qcaspi *qca = NULL;
 859	struct net_device *qcaspi_devs = NULL;
 860	u8 legacy_mode = 0;
 861	u16 signature;
 862	const char *mac;
 863
 864	if (!spi->dev.of_node) {
 865		dev_err(&spi->dev, "Missing device tree\n");
 866		return -EINVAL;
 867	}
 868
 869	legacy_mode = of_property_read_bool(spi->dev.of_node,
 870					    "qca,legacy-mode");
 871
 872	if (qcaspi_clkspeed == 0) {
 873		if (spi->max_speed_hz)
 874			qcaspi_clkspeed = spi->max_speed_hz;
 875		else
 876			qcaspi_clkspeed = QCASPI_CLK_SPEED;
 877	}
 878
 879	if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
 880	    (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
 881		dev_info(&spi->dev, "Invalid clkspeed: %d\n",
 882			 qcaspi_clkspeed);
 883		return -EINVAL;
 884	}
 885
 886	if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
 887	    (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
 888		dev_info(&spi->dev, "Invalid burst len: %d\n",
 889			 qcaspi_burst_len);
 890		return -EINVAL;
 891	}
 892
 893	if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
 894	    (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
 895		dev_info(&spi->dev, "Invalid pluggable: %d\n",
 896			 qcaspi_pluggable);
 897		return -EINVAL;
 898	}
 899
 900	dev_info(&spi->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
 901		 QCASPI_DRV_VERSION,
 902		 qcaspi_clkspeed,
 903		 qcaspi_burst_len,
 904		 qcaspi_pluggable);
 905
 906	spi->mode = SPI_MODE_3;
 907	spi->max_speed_hz = qcaspi_clkspeed;
 908	if (spi_setup(spi) < 0) {
 909		dev_err(&spi->dev, "Unable to setup SPI device\n");
 910		return -EFAULT;
 911	}
 912
 913	qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
 914	if (!qcaspi_devs)
 915		return -ENOMEM;
 916
 917	qcaspi_netdev_setup(qcaspi_devs);
 918	SET_NETDEV_DEV(qcaspi_devs, &spi->dev);
 919
 920	qca = netdev_priv(qcaspi_devs);
 921	if (!qca) {
 922		free_netdev(qcaspi_devs);
 923		dev_err(&spi->dev, "Fail to retrieve private structure\n");
 924		return -ENOMEM;
 925	}
 926	qca->net_dev = qcaspi_devs;
 927	qca->spi_dev = spi;
 928	qca->legacy_mode = legacy_mode;
 929
 930	spi_set_drvdata(spi, qcaspi_devs);
 931
 932	mac = of_get_mac_address(spi->dev.of_node);
 933
 934	if (mac)
 935		ether_addr_copy(qca->net_dev->dev_addr, mac);
 936
 937	if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
 938		eth_hw_addr_random(qca->net_dev);
 939		dev_info(&spi->dev, "Using random MAC address: %pM\n",
 940			 qca->net_dev->dev_addr);
 941	}
 942
 943	netif_carrier_off(qca->net_dev);
 944
 945	if (!qcaspi_pluggable) {
 946		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 947		qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
 948
 949		if (signature != QCASPI_GOOD_SIGNATURE) {
 950			dev_err(&spi->dev, "Invalid signature (0x%04X)\n",
 951				signature);
 952			free_netdev(qcaspi_devs);
 953			return -EFAULT;
 954		}
 955	}
 956
 957	if (register_netdev(qcaspi_devs)) {
 958		dev_info(&spi->dev, "Unable to register net device %s\n",
 959			 qcaspi_devs->name);
 960		free_netdev(qcaspi_devs);
 961		return -EFAULT;
 962	}
 963
 964	qcaspi_init_device_debugfs(qca);
 965
 966	return 0;
 967}
 968
 969static int
 970qca_spi_remove(struct spi_device *spi)
 971{
 972	struct net_device *qcaspi_devs = spi_get_drvdata(spi);
 973	struct qcaspi *qca = netdev_priv(qcaspi_devs);
 974
 975	qcaspi_remove_device_debugfs(qca);
 976
 977	unregister_netdev(qcaspi_devs);
 978	free_netdev(qcaspi_devs);
 979
 980	return 0;
 981}
 982
 983static const struct spi_device_id qca_spi_id[] = {
 984	{ "qca7000", 0 },
 985	{ /* sentinel */ }
 986};
 987MODULE_DEVICE_TABLE(spi, qca_spi_id);
 988
 989static struct spi_driver qca_spi_driver = {
 990	.driver	= {
 991		.name	= QCASPI_DRV_NAME,
 992		.of_match_table = qca_spi_of_match,
 993	},
 994	.id_table = qca_spi_id,
 995	.probe    = qca_spi_probe,
 996	.remove   = qca_spi_remove,
 997};
 998module_spi_driver(qca_spi_driver);
 999
1000MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 SPI Driver");
1001MODULE_AUTHOR("Qualcomm Atheros Communications");
1002MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
1003MODULE_LICENSE("Dual BSD/GPL");
1004MODULE_VERSION(QCASPI_DRV_VERSION);