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[mirror_ubuntu-artful-kernel.git] / 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_debug.h"
47 #include "qca_framing.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_MTU QCAFRM_ETHMAXMTU
73 #define QCASPI_TX_TIMEOUT (1 * HZ)
74 #define QCASPI_QCA7K_REBOOT_TIME_MS 1000
75
76 static void
77 start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)
78 {
79 *intr_cause = 0;
80
81 qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
82 qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
83 netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);
84 }
85
86 static void
87 end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)
88 {
89 u16 intr_enable = (SPI_INT_CPU_ON |
90 SPI_INT_PKT_AVLBL |
91 SPI_INT_RDBUF_ERR |
92 SPI_INT_WRBUF_ERR);
93
94 qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
95 qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable);
96 netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);
97 }
98
99 static u32
100 qcaspi_write_burst(struct qcaspi *qca, u8 *src, u32 len)
101 {
102 __be16 cmd;
103 struct spi_message *msg = &qca->spi_msg2;
104 struct spi_transfer *transfer = &qca->spi_xfer2[0];
105 int ret;
106
107 cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
108 transfer->tx_buf = &cmd;
109 transfer->rx_buf = NULL;
110 transfer->len = QCASPI_CMD_LEN;
111 transfer = &qca->spi_xfer2[1];
112 transfer->tx_buf = src;
113 transfer->rx_buf = NULL;
114 transfer->len = len;
115
116 ret = spi_sync(qca->spi_dev, msg);
117
118 if (ret || (msg->actual_length != QCASPI_CMD_LEN + len)) {
119 qcaspi_spi_error(qca);
120 return 0;
121 }
122
123 return len;
124 }
125
126 static u32
127 qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)
128 {
129 struct spi_message *msg = &qca->spi_msg1;
130 struct spi_transfer *transfer = &qca->spi_xfer1;
131 int ret;
132
133 transfer->tx_buf = src;
134 transfer->rx_buf = NULL;
135 transfer->len = len;
136
137 ret = spi_sync(qca->spi_dev, msg);
138
139 if (ret || (msg->actual_length != len)) {
140 qcaspi_spi_error(qca);
141 return 0;
142 }
143
144 return len;
145 }
146
147 static u32
148 qcaspi_read_burst(struct qcaspi *qca, u8 *dst, u32 len)
149 {
150 struct spi_message *msg = &qca->spi_msg2;
151 __be16 cmd;
152 struct spi_transfer *transfer = &qca->spi_xfer2[0];
153 int ret;
154
155 cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
156 transfer->tx_buf = &cmd;
157 transfer->rx_buf = NULL;
158 transfer->len = QCASPI_CMD_LEN;
159 transfer = &qca->spi_xfer2[1];
160 transfer->tx_buf = NULL;
161 transfer->rx_buf = dst;
162 transfer->len = len;
163
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 = &qca->spi_msg1;
178 struct spi_transfer *transfer = &qca->spi_xfer1;
179 int ret;
180
181 transfer->tx_buf = NULL;
182 transfer->rx_buf = dst;
183 transfer->len = len;
184
185 ret = spi_sync(qca->spi_dev, msg);
186
187 if (ret || (msg->actual_length != len)) {
188 qcaspi_spi_error(qca);
189 return 0;
190 }
191
192 return len;
193 }
194
195 static int
196 qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
197 {
198 u32 count;
199 u32 written;
200 u32 offset;
201 u32 len;
202
203 len = skb->len;
204
205 qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len);
206 if (qca->legacy_mode)
207 qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
208
209 offset = 0;
210 while (len) {
211 count = len;
212 if (count > qca->burst_len)
213 count = qca->burst_len;
214
215 if (qca->legacy_mode) {
216 written = qcaspi_write_legacy(qca,
217 skb->data + offset,
218 count);
219 } else {
220 written = qcaspi_write_burst(qca,
221 skb->data + offset,
222 count);
223 }
224
225 if (written != count)
226 return -1;
227
228 offset += count;
229 len -= count;
230 }
231
232 return 0;
233 }
234
235 static int
236 qcaspi_transmit(struct qcaspi *qca)
237 {
238 struct net_device_stats *n_stats = &qca->net_dev->stats;
239 u16 available = 0;
240 u32 pkt_len;
241 u16 new_head;
242 u16 packets = 0;
243
244 if (qca->txr.skb[qca->txr.head] == NULL)
245 return 0;
246
247 qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, &available);
248
249 while (qca->txr.skb[qca->txr.head]) {
250 pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;
251
252 if (available < pkt_len) {
253 if (packets == 0)
254 qca->stats.write_buf_miss++;
255 break;
256 }
257
258 if (qcaspi_tx_frame(qca, qca->txr.skb[qca->txr.head]) == -1) {
259 qca->stats.write_err++;
260 return -1;
261 }
262
263 packets++;
264 n_stats->tx_packets++;
265 n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;
266 available -= pkt_len;
267
268 /* remove the skb from the queue */
269 /* XXX After inconsistent lock states netif_tx_lock()
270 * has been replaced by netif_tx_lock_bh() and so on.
271 */
272 netif_tx_lock_bh(qca->net_dev);
273 dev_kfree_skb(qca->txr.skb[qca->txr.head]);
274 qca->txr.skb[qca->txr.head] = NULL;
275 qca->txr.size -= pkt_len;
276 new_head = qca->txr.head + 1;
277 if (new_head >= qca->txr.count)
278 new_head = 0;
279 qca->txr.head = new_head;
280 if (netif_queue_stopped(qca->net_dev))
281 netif_wake_queue(qca->net_dev);
282 netif_tx_unlock_bh(qca->net_dev);
283 }
284
285 return 0;
286 }
287
288 static int
289 qcaspi_receive(struct qcaspi *qca)
290 {
291 struct net_device *net_dev = qca->net_dev;
292 struct net_device_stats *n_stats = &net_dev->stats;
293 u16 available = 0;
294 u32 bytes_read;
295 u8 *cp;
296
297 /* Allocate rx SKB if we don't have one available. */
298 if (!qca->rx_skb) {
299 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
300 net_dev->mtu +
301 VLAN_ETH_HLEN);
302 if (!qca->rx_skb) {
303 netdev_dbg(net_dev, "out of RX resources\n");
304 qca->stats.out_of_mem++;
305 return -1;
306 }
307 }
308
309 /* Read the packet size. */
310 qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, &available);
311 netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %08x\n",
312 available);
313
314 if (available == 0) {
315 netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");
316 return -1;
317 }
318
319 qcaspi_write_register(qca, SPI_REG_BFR_SIZE, available);
320
321 if (qca->legacy_mode)
322 qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
323
324 while (available) {
325 u32 count = available;
326
327 if (count > qca->burst_len)
328 count = qca->burst_len;
329
330 if (qca->legacy_mode) {
331 bytes_read = qcaspi_read_legacy(qca, qca->rx_buffer,
332 count);
333 } else {
334 bytes_read = qcaspi_read_burst(qca, qca->rx_buffer,
335 count);
336 }
337
338 netdev_dbg(net_dev, "available: %d, byte read: %d\n",
339 available, bytes_read);
340
341 if (bytes_read) {
342 available -= bytes_read;
343 } else {
344 qca->stats.read_err++;
345 return -1;
346 }
347
348 cp = qca->rx_buffer;
349
350 while ((bytes_read--) && (qca->rx_skb)) {
351 s32 retcode;
352
353 retcode = qcafrm_fsm_decode(&qca->frm_handle,
354 qca->rx_skb->data,
355 skb_tailroom(qca->rx_skb),
356 *cp);
357 cp++;
358 switch (retcode) {
359 case QCAFRM_GATHER:
360 case QCAFRM_NOHEAD:
361 break;
362 case QCAFRM_NOTAIL:
363 netdev_dbg(net_dev, "no RX tail\n");
364 n_stats->rx_errors++;
365 n_stats->rx_dropped++;
366 break;
367 case QCAFRM_INVLEN:
368 netdev_dbg(net_dev, "invalid RX length\n");
369 n_stats->rx_errors++;
370 n_stats->rx_dropped++;
371 break;
372 default:
373 qca->rx_skb->dev = qca->net_dev;
374 n_stats->rx_packets++;
375 n_stats->rx_bytes += retcode;
376 skb_put(qca->rx_skb, retcode);
377 qca->rx_skb->protocol = eth_type_trans(
378 qca->rx_skb, qca->rx_skb->dev);
379 qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
380 netif_rx_ni(qca->rx_skb);
381 qca->rx_skb = netdev_alloc_skb_ip_align(net_dev,
382 net_dev->mtu + VLAN_ETH_HLEN);
383 if (!qca->rx_skb) {
384 netdev_dbg(net_dev, "out of RX resources\n");
385 n_stats->rx_errors++;
386 qca->stats.out_of_mem++;
387 break;
388 }
389 }
390 }
391 }
392
393 return 0;
394 }
395
396 /* Check that tx ring stores only so much bytes
397 * that fit into the internal QCA buffer.
398 */
399
400 static int
401 qcaspi_tx_ring_has_space(struct tx_ring *txr)
402 {
403 if (txr->skb[txr->tail])
404 return 0;
405
406 return (txr->size + QCAFRM_ETHMAXLEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
407 }
408
409 /* Flush the tx ring. This function is only safe to
410 * call from the qcaspi_spi_thread.
411 */
412
413 static void
414 qcaspi_flush_tx_ring(struct qcaspi *qca)
415 {
416 int i;
417
418 /* XXX After inconsistent lock states netif_tx_lock()
419 * has been replaced by netif_tx_lock_bh() and so on.
420 */
421 netif_tx_lock_bh(qca->net_dev);
422 for (i = 0; i < TX_RING_MAX_LEN; i++) {
423 if (qca->txr.skb[i]) {
424 dev_kfree_skb(qca->txr.skb[i]);
425 qca->txr.skb[i] = NULL;
426 qca->net_dev->stats.tx_dropped++;
427 }
428 }
429 qca->txr.tail = 0;
430 qca->txr.head = 0;
431 qca->txr.size = 0;
432 netif_tx_unlock_bh(qca->net_dev);
433 }
434
435 static void
436 qcaspi_qca7k_sync(struct qcaspi *qca, int event)
437 {
438 u16 signature = 0;
439 u16 spi_config;
440 u16 wrbuf_space = 0;
441 static u16 reset_count;
442
443 if (event == QCASPI_EVENT_CPUON) {
444 /* Read signature twice, if not valid
445 * go back to unknown state.
446 */
447 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
448 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
449 if (signature != QCASPI_GOOD_SIGNATURE) {
450 qca->sync = QCASPI_SYNC_UNKNOWN;
451 netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");
452 } else {
453 /* ensure that the WRBUF is empty */
454 qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,
455 &wrbuf_space);
456 if (wrbuf_space != QCASPI_HW_BUF_LEN) {
457 netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");
458 qca->sync = QCASPI_SYNC_UNKNOWN;
459 } else {
460 netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");
461 qca->sync = QCASPI_SYNC_READY;
462 return;
463 }
464 }
465 }
466
467 switch (qca->sync) {
468 case QCASPI_SYNC_READY:
469 /* Read signature, if not valid go to unknown state. */
470 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
471 if (signature != QCASPI_GOOD_SIGNATURE) {
472 qca->sync = QCASPI_SYNC_UNKNOWN;
473 netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");
474 /* don't reset right away */
475 return;
476 }
477 break;
478 case QCASPI_SYNC_UNKNOWN:
479 /* Read signature, if not valid stay in unknown state */
480 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
481 if (signature != QCASPI_GOOD_SIGNATURE) {
482 netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");
483 return;
484 }
485
486 /* TODO: use GPIO to reset QCA7000 in legacy mode*/
487 netdev_dbg(qca->net_dev, "sync: resetting device.\n");
488 qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, &spi_config);
489 spi_config |= QCASPI_SLAVE_RESET_BIT;
490 qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, spi_config);
491
492 qca->sync = QCASPI_SYNC_RESET;
493 qca->stats.trig_reset++;
494 reset_count = 0;
495 break;
496 case QCASPI_SYNC_RESET:
497 reset_count++;
498 netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",
499 reset_count);
500 if (reset_count >= QCASPI_RESET_TIMEOUT) {
501 /* reset did not seem to take place, try again */
502 qca->sync = QCASPI_SYNC_UNKNOWN;
503 qca->stats.reset_timeout++;
504 netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");
505 }
506 break;
507 }
508 }
509
510 static int
511 qcaspi_spi_thread(void *data)
512 {
513 struct qcaspi *qca = data;
514 u16 intr_cause = 0;
515
516 netdev_info(qca->net_dev, "SPI thread created\n");
517 while (!kthread_should_stop()) {
518 set_current_state(TASK_INTERRUPTIBLE);
519 if ((qca->intr_req == qca->intr_svc) &&
520 (qca->txr.skb[qca->txr.head] == NULL) &&
521 (qca->sync == QCASPI_SYNC_READY))
522 schedule();
523
524 set_current_state(TASK_RUNNING);
525
526 netdev_dbg(qca->net_dev, "have work to do. int: %d, tx_skb: %p\n",
527 qca->intr_req - qca->intr_svc,
528 qca->txr.skb[qca->txr.head]);
529
530 qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
531
532 if (qca->sync != QCASPI_SYNC_READY) {
533 netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",
534 (unsigned int)qca->sync);
535 netif_stop_queue(qca->net_dev);
536 netif_carrier_off(qca->net_dev);
537 qcaspi_flush_tx_ring(qca);
538 msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
539 }
540
541 if (qca->intr_svc != qca->intr_req) {
542 qca->intr_svc = qca->intr_req;
543 start_spi_intr_handling(qca, &intr_cause);
544
545 if (intr_cause & SPI_INT_CPU_ON) {
546 qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);
547
548 /* not synced. */
549 if (qca->sync != QCASPI_SYNC_READY)
550 continue;
551
552 qca->stats.device_reset++;
553 netif_wake_queue(qca->net_dev);
554 netif_carrier_on(qca->net_dev);
555 }
556
557 if (intr_cause & SPI_INT_RDBUF_ERR) {
558 /* restart sync */
559 netdev_dbg(qca->net_dev, "===> rdbuf error!\n");
560 qca->stats.read_buf_err++;
561 qca->sync = QCASPI_SYNC_UNKNOWN;
562 continue;
563 }
564
565 if (intr_cause & SPI_INT_WRBUF_ERR) {
566 /* restart sync */
567 netdev_dbg(qca->net_dev, "===> wrbuf error!\n");
568 qca->stats.write_buf_err++;
569 qca->sync = QCASPI_SYNC_UNKNOWN;
570 continue;
571 }
572
573 /* can only handle other interrupts
574 * if sync has occurred
575 */
576 if (qca->sync == QCASPI_SYNC_READY) {
577 if (intr_cause & SPI_INT_PKT_AVLBL)
578 qcaspi_receive(qca);
579 }
580
581 end_spi_intr_handling(qca, intr_cause);
582 }
583
584 if (qca->sync == QCASPI_SYNC_READY)
585 qcaspi_transmit(qca);
586 }
587 set_current_state(TASK_RUNNING);
588 netdev_info(qca->net_dev, "SPI thread exit\n");
589
590 return 0;
591 }
592
593 static irqreturn_t
594 qcaspi_intr_handler(int irq, void *data)
595 {
596 struct qcaspi *qca = data;
597
598 qca->intr_req++;
599 if (qca->spi_thread &&
600 qca->spi_thread->state != TASK_RUNNING)
601 wake_up_process(qca->spi_thread);
602
603 return IRQ_HANDLED;
604 }
605
606 int
607 qcaspi_netdev_open(struct net_device *dev)
608 {
609 struct qcaspi *qca = netdev_priv(dev);
610 int ret = 0;
611
612 if (!qca)
613 return -EINVAL;
614
615 qca->intr_req = 1;
616 qca->intr_svc = 0;
617 qca->sync = QCASPI_SYNC_UNKNOWN;
618 qcafrm_fsm_init(&qca->frm_handle);
619
620 qca->spi_thread = kthread_run((void *)qcaspi_spi_thread,
621 qca, "%s", dev->name);
622
623 if (IS_ERR(qca->spi_thread)) {
624 netdev_err(dev, "%s: unable to start kernel thread.\n",
625 QCASPI_DRV_NAME);
626 return PTR_ERR(qca->spi_thread);
627 }
628
629 ret = request_irq(qca->spi_dev->irq, qcaspi_intr_handler, 0,
630 dev->name, qca);
631 if (ret) {
632 netdev_err(dev, "%s: unable to get IRQ %d (irqval=%d).\n",
633 QCASPI_DRV_NAME, qca->spi_dev->irq, ret);
634 kthread_stop(qca->spi_thread);
635 return ret;
636 }
637
638 netif_start_queue(qca->net_dev);
639
640 return 0;
641 }
642
643 int
644 qcaspi_netdev_close(struct net_device *dev)
645 {
646 struct qcaspi *qca = netdev_priv(dev);
647
648 netif_stop_queue(dev);
649
650 qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
651 free_irq(qca->spi_dev->irq, qca);
652
653 kthread_stop(qca->spi_thread);
654 qca->spi_thread = NULL;
655 qcaspi_flush_tx_ring(qca);
656
657 return 0;
658 }
659
660 static netdev_tx_t
661 qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
662 {
663 u32 frame_len;
664 u8 *ptmp;
665 struct qcaspi *qca = netdev_priv(dev);
666 u16 new_tail;
667 struct sk_buff *tskb;
668 u8 pad_len = 0;
669
670 if (skb->len < QCAFRM_ETHMINLEN)
671 pad_len = QCAFRM_ETHMINLEN - skb->len;
672
673 if (qca->txr.skb[qca->txr.tail]) {
674 netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");
675 netif_stop_queue(qca->net_dev);
676 qca->stats.ring_full++;
677 return NETDEV_TX_BUSY;
678 }
679
680 if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||
681 (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {
682 tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,
683 QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);
684 if (!tskb) {
685 netdev_dbg(qca->net_dev, "could not allocate tx_buff\n");
686 qca->stats.out_of_mem++;
687 return NETDEV_TX_BUSY;
688 }
689 dev_kfree_skb(skb);
690 skb = tskb;
691 }
692
693 frame_len = skb->len + pad_len;
694
695 ptmp = skb_push(skb, QCAFRM_HEADER_LEN);
696 qcafrm_create_header(ptmp, frame_len);
697
698 if (pad_len) {
699 ptmp = skb_put(skb, pad_len);
700 memset(ptmp, 0, pad_len);
701 }
702
703 ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);
704 qcafrm_create_footer(ptmp);
705
706 netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",
707 skb->len);
708
709 qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;
710
711 new_tail = qca->txr.tail + 1;
712 if (new_tail >= qca->txr.count)
713 new_tail = 0;
714
715 qca->txr.skb[qca->txr.tail] = skb;
716 qca->txr.tail = new_tail;
717
718 if (!qcaspi_tx_ring_has_space(&qca->txr)) {
719 netif_stop_queue(qca->net_dev);
720 qca->stats.ring_full++;
721 }
722
723 netif_trans_update(dev);
724
725 if (qca->spi_thread &&
726 qca->spi_thread->state != TASK_RUNNING)
727 wake_up_process(qca->spi_thread);
728
729 return NETDEV_TX_OK;
730 }
731
732 static void
733 qcaspi_netdev_tx_timeout(struct net_device *dev)
734 {
735 struct qcaspi *qca = netdev_priv(dev);
736
737 netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
738 jiffies, jiffies - dev_trans_start(dev));
739 qca->net_dev->stats.tx_errors++;
740 /* Trigger tx queue flush and QCA7000 reset */
741 qca->sync = QCASPI_SYNC_UNKNOWN;
742 }
743
744 static int
745 qcaspi_netdev_init(struct net_device *dev)
746 {
747 struct qcaspi *qca = netdev_priv(dev);
748
749 dev->mtu = QCASPI_MTU;
750 dev->type = ARPHRD_ETHER;
751 qca->clkspeed = qcaspi_clkspeed;
752 qca->burst_len = qcaspi_burst_len;
753 qca->spi_thread = NULL;
754 qca->buffer_size = (dev->mtu + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +
755 QCAFRM_FOOTER_LEN + 4) * 4;
756
757 memset(&qca->stats, 0, sizeof(struct qcaspi_stats));
758
759 qca->rx_buffer = kmalloc(qca->buffer_size, GFP_KERNEL);
760 if (!qca->rx_buffer)
761 return -ENOBUFS;
762
763 qca->rx_skb = netdev_alloc_skb_ip_align(dev, qca->net_dev->mtu +
764 VLAN_ETH_HLEN);
765 if (!qca->rx_skb) {
766 kfree(qca->rx_buffer);
767 netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
768 return -ENOBUFS;
769 }
770
771 return 0;
772 }
773
774 static void
775 qcaspi_netdev_uninit(struct net_device *dev)
776 {
777 struct qcaspi *qca = netdev_priv(dev);
778
779 kfree(qca->rx_buffer);
780 qca->buffer_size = 0;
781 if (qca->rx_skb)
782 dev_kfree_skb(qca->rx_skb);
783 }
784
785 static const struct net_device_ops qcaspi_netdev_ops = {
786 .ndo_init = qcaspi_netdev_init,
787 .ndo_uninit = qcaspi_netdev_uninit,
788 .ndo_open = qcaspi_netdev_open,
789 .ndo_stop = qcaspi_netdev_close,
790 .ndo_start_xmit = qcaspi_netdev_xmit,
791 .ndo_set_mac_address = eth_mac_addr,
792 .ndo_tx_timeout = qcaspi_netdev_tx_timeout,
793 .ndo_validate_addr = eth_validate_addr,
794 };
795
796 static void
797 qcaspi_netdev_setup(struct net_device *dev)
798 {
799 struct qcaspi *qca = NULL;
800
801 dev->netdev_ops = &qcaspi_netdev_ops;
802 qcaspi_set_ethtool_ops(dev);
803 dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
804 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
805 dev->tx_queue_len = 100;
806
807 /* MTU range: 46 - 1500 */
808 dev->min_mtu = QCAFRM_ETHMINMTU;
809 dev->max_mtu = QCAFRM_ETHMAXMTU;
810
811 qca = netdev_priv(dev);
812 memset(qca, 0, sizeof(struct qcaspi));
813
814 memset(&qca->spi_xfer1, 0, sizeof(struct spi_transfer));
815 memset(&qca->spi_xfer2, 0, sizeof(struct spi_transfer) * 2);
816
817 spi_message_init(&qca->spi_msg1);
818 spi_message_add_tail(&qca->spi_xfer1, &qca->spi_msg1);
819
820 spi_message_init(&qca->spi_msg2);
821 spi_message_add_tail(&qca->spi_xfer2[0], &qca->spi_msg2);
822 spi_message_add_tail(&qca->spi_xfer2[1], &qca->spi_msg2);
823
824 memset(&qca->txr, 0, sizeof(qca->txr));
825 qca->txr.count = TX_RING_MAX_LEN;
826 }
827
828 static const struct of_device_id qca_spi_of_match[] = {
829 { .compatible = "qca,qca7000" },
830 { /* sentinel */ }
831 };
832 MODULE_DEVICE_TABLE(of, qca_spi_of_match);
833
834 static int
835 qca_spi_probe(struct spi_device *spi)
836 {
837 struct qcaspi *qca = NULL;
838 struct net_device *qcaspi_devs = NULL;
839 u8 legacy_mode = 0;
840 u16 signature;
841 const char *mac;
842
843 if (!spi->dev.of_node) {
844 dev_err(&spi->dev, "Missing device tree\n");
845 return -EINVAL;
846 }
847
848 legacy_mode = of_property_read_bool(spi->dev.of_node,
849 "qca,legacy-mode");
850
851 if (qcaspi_clkspeed == 0) {
852 if (spi->max_speed_hz)
853 qcaspi_clkspeed = spi->max_speed_hz;
854 else
855 qcaspi_clkspeed = QCASPI_CLK_SPEED;
856 }
857
858 if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
859 (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
860 dev_info(&spi->dev, "Invalid clkspeed: %d\n",
861 qcaspi_clkspeed);
862 return -EINVAL;
863 }
864
865 if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
866 (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
867 dev_info(&spi->dev, "Invalid burst len: %d\n",
868 qcaspi_burst_len);
869 return -EINVAL;
870 }
871
872 if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
873 (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
874 dev_info(&spi->dev, "Invalid pluggable: %d\n",
875 qcaspi_pluggable);
876 return -EINVAL;
877 }
878
879 dev_info(&spi->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
880 QCASPI_DRV_VERSION,
881 qcaspi_clkspeed,
882 qcaspi_burst_len,
883 qcaspi_pluggable);
884
885 spi->mode = SPI_MODE_3;
886 spi->max_speed_hz = qcaspi_clkspeed;
887 if (spi_setup(spi) < 0) {
888 dev_err(&spi->dev, "Unable to setup SPI device\n");
889 return -EFAULT;
890 }
891
892 qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
893 if (!qcaspi_devs)
894 return -ENOMEM;
895
896 qcaspi_netdev_setup(qcaspi_devs);
897
898 qca = netdev_priv(qcaspi_devs);
899 if (!qca) {
900 free_netdev(qcaspi_devs);
901 dev_err(&spi->dev, "Fail to retrieve private structure\n");
902 return -ENOMEM;
903 }
904 qca->net_dev = qcaspi_devs;
905 qca->spi_dev = spi;
906 qca->legacy_mode = legacy_mode;
907
908 spi_set_drvdata(spi, qcaspi_devs);
909
910 mac = of_get_mac_address(spi->dev.of_node);
911
912 if (mac)
913 ether_addr_copy(qca->net_dev->dev_addr, mac);
914
915 if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
916 eth_hw_addr_random(qca->net_dev);
917 dev_info(&spi->dev, "Using random MAC address: %pM\n",
918 qca->net_dev->dev_addr);
919 }
920
921 netif_carrier_off(qca->net_dev);
922
923 if (!qcaspi_pluggable) {
924 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
925 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
926
927 if (signature != QCASPI_GOOD_SIGNATURE) {
928 dev_err(&spi->dev, "Invalid signature (0x%04X)\n",
929 signature);
930 free_netdev(qcaspi_devs);
931 return -EFAULT;
932 }
933 }
934
935 if (register_netdev(qcaspi_devs)) {
936 dev_info(&spi->dev, "Unable to register net device %s\n",
937 qcaspi_devs->name);
938 free_netdev(qcaspi_devs);
939 return -EFAULT;
940 }
941
942 qcaspi_init_device_debugfs(qca);
943
944 return 0;
945 }
946
947 static int
948 qca_spi_remove(struct spi_device *spi)
949 {
950 struct net_device *qcaspi_devs = spi_get_drvdata(spi);
951 struct qcaspi *qca = netdev_priv(qcaspi_devs);
952
953 qcaspi_remove_device_debugfs(qca);
954
955 unregister_netdev(qcaspi_devs);
956 free_netdev(qcaspi_devs);
957
958 return 0;
959 }
960
961 static const struct spi_device_id qca_spi_id[] = {
962 { "qca7000", 0 },
963 { /* sentinel */ }
964 };
965 MODULE_DEVICE_TABLE(spi, qca_spi_id);
966
967 static struct spi_driver qca_spi_driver = {
968 .driver = {
969 .name = QCASPI_DRV_NAME,
970 .of_match_table = qca_spi_of_match,
971 },
972 .id_table = qca_spi_id,
973 .probe = qca_spi_probe,
974 .remove = qca_spi_remove,
975 };
976 module_spi_driver(qca_spi_driver);
977
978 MODULE_DESCRIPTION("Qualcomm Atheros SPI Driver");
979 MODULE_AUTHOR("Qualcomm Atheros Communications");
980 MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
981 MODULE_LICENSE("Dual BSD/GPL");
982 MODULE_VERSION(QCASPI_DRV_VERSION);