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 #include <linux/version.h>
45
46 #include "qca_7k.h"
47 #include "qca_debug.h"
48 #include "qca_framing.h"
49 #include "qca_spi.h"
50
51 #define MAX_DMA_BURST_LEN 5000
52
53 /* Modules parameters */
54 #define QCASPI_CLK_SPEED_MIN 1000000
55 #define QCASPI_CLK_SPEED_MAX 16000000
56 #define QCASPI_CLK_SPEED 8000000
57 static int qcaspi_clkspeed;
58 module_param(qcaspi_clkspeed, int, 0);
59 MODULE_PARM_DESC(qcaspi_clkspeed, "SPI bus clock speed (Hz). Use 1000000-16000000.");
60
61 #define QCASPI_BURST_LEN_MIN 1
62 #define QCASPI_BURST_LEN_MAX MAX_DMA_BURST_LEN
63 static int qcaspi_burst_len = MAX_DMA_BURST_LEN;
64 module_param(qcaspi_burst_len, int, 0);
65 MODULE_PARM_DESC(qcaspi_burst_len, "Number of data bytes per burst. Use 1-5000.");
66
67 #define QCASPI_PLUGGABLE_MIN 0
68 #define QCASPI_PLUGGABLE_MAX 1
69 static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;
70 module_param(qcaspi_pluggable, int, 0);
71 MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");
72
73 #define QCASPI_MTU QCAFRM_ETHMAXMTU
74 #define QCASPI_TX_TIMEOUT (1 * HZ)
75 #define QCASPI_QCA7K_REBOOT_TIME_MS 1000
76
77 static void
start_spi_intr_handling(struct qcaspi * qca,u16 * intr_cause)78 start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)
79 {
80 *intr_cause = 0;
81
82 qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, 0);
83 qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
84 netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);
85 }
86
87 static void
end_spi_intr_handling(struct qcaspi * qca,u16 intr_cause)88 end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)
89 {
90 u16 intr_enable = (SPI_INT_CPU_ON |
91 SPI_INT_PKT_AVLBL |
92 SPI_INT_RDBUF_ERR |
93 SPI_INT_WRBUF_ERR);
94
95 qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, intr_cause);
96 qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, intr_enable);
97 netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);
98 }
99
100 static u32
qcaspi_write_burst(struct qcaspi * qca,u8 * src,u32 len)101 qcaspi_write_burst(struct qcaspi *qca, u8 *src, u32 len)
102 {
103 __be16 cmd;
104 struct spi_message *msg = &qca->spi_msg2;
105 struct spi_transfer *transfer = &qca->spi_xfer2[0];
106 int ret;
107
108 cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
109 transfer->tx_buf = &cmd;
110 transfer->rx_buf = NULL;
111 transfer->len = QCASPI_CMD_LEN;
112 transfer = &qca->spi_xfer2[1];
113 transfer->tx_buf = src;
114 transfer->rx_buf = NULL;
115 transfer->len = len;
116
117 ret = spi_sync(qca->spi_dev, msg);
118
119 if (ret || (msg->actual_length != QCASPI_CMD_LEN + len)) {
120 qcaspi_spi_error(qca);
121 return 0;
122 }
123
124 return len;
125 }
126
127 static u32
qcaspi_write_legacy(struct qcaspi * qca,u8 * src,u32 len)128 qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)
129 {
130 struct spi_message *msg = &qca->spi_msg1;
131 struct spi_transfer *transfer = &qca->spi_xfer1;
132 int ret;
133
134 transfer->tx_buf = src;
135 transfer->rx_buf = NULL;
136 transfer->len = len;
137
138 ret = spi_sync(qca->spi_dev, msg);
139
140 if (ret || (msg->actual_length != len)) {
141 qcaspi_spi_error(qca);
142 return 0;
143 }
144
145 return len;
146 }
147
148 static u32
qcaspi_read_burst(struct qcaspi * qca,u8 * dst,u32 len)149 qcaspi_read_burst(struct qcaspi *qca, u8 *dst, u32 len)
150 {
151 struct spi_message *msg = &qca->spi_msg2;
152 __be16 cmd;
153 struct spi_transfer *transfer = &qca->spi_xfer2[0];
154 int ret;
155
156 cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
157 transfer->tx_buf = &cmd;
158 transfer->rx_buf = NULL;
159 transfer->len = QCASPI_CMD_LEN;
160 transfer = &qca->spi_xfer2[1];
161 transfer->tx_buf = NULL;
162 transfer->rx_buf = dst;
163 transfer->len = len;
164
165 ret = spi_sync(qca->spi_dev, msg);
166
167 if (ret || (msg->actual_length != QCASPI_CMD_LEN + len)) {
168 qcaspi_spi_error(qca);
169 return 0;
170 }
171
172 return len;
173 }
174
175 static u32
qcaspi_read_legacy(struct qcaspi * qca,u8 * dst,u32 len)176 qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)
177 {
178 struct spi_message *msg = &qca->spi_msg1;
179 struct spi_transfer *transfer = &qca->spi_xfer1;
180 int ret;
181
182 transfer->tx_buf = NULL;
183 transfer->rx_buf = dst;
184 transfer->len = len;
185
186 ret = spi_sync(qca->spi_dev, msg);
187
188 if (ret || (msg->actual_length != len)) {
189 qcaspi_spi_error(qca);
190 return 0;
191 }
192
193 return len;
194 }
195
196 static int
qcaspi_tx_frame(struct qcaspi * qca,struct sk_buff * skb)197 qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
198 {
199 u32 count;
200 u32 written;
201 u32 offset;
202 u32 len;
203
204 len = skb->len;
205
206 qcaspi_write_register(qca, SPI_REG_BFR_SIZE, len);
207 if (qca->legacy_mode)
208 qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
209
210 offset = 0;
211 while (len) {
212 count = len;
213 if (count > qca->burst_len)
214 count = qca->burst_len;
215
216 if (qca->legacy_mode) {
217 written = qcaspi_write_legacy(qca,
218 skb->data + offset,
219 count);
220 } else {
221 written = qcaspi_write_burst(qca,
222 skb->data + offset,
223 count);
224 }
225
226 if (written != count)
227 return -1;
228
229 offset += count;
230 len -= count;
231 }
232
233 return 0;
234 }
235
236 static int
qcaspi_transmit(struct qcaspi * qca)237 qcaspi_transmit(struct qcaspi *qca)
238 {
239 struct net_device_stats *n_stats = &qca->net_dev->stats;
240 u16 available = 0;
241 u32 pkt_len;
242 u16 new_head;
243 u16 packets = 0;
244
245 if (qca->txr.skb[qca->txr.head] == NULL)
246 return 0;
247
248 qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, &available);
249
250 while (qca->txr.skb[qca->txr.head]) {
251 pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;
252
253 if (available < pkt_len) {
254 if (packets == 0)
255 qca->stats.write_buf_miss++;
256 break;
257 }
258
259 if (qcaspi_tx_frame(qca, qca->txr.skb[qca->txr.head]) == -1) {
260 qca->stats.write_err++;
261 return -1;
262 }
263
264 packets++;
265 n_stats->tx_packets++;
266 n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;
267 available -= pkt_len;
268
269 /* remove the skb from the queue */
270 /* XXX After inconsistent lock states netif_tx_lock()
271 * has been replaced by netif_tx_lock_bh() and so on.
272 */
273 netif_tx_lock_bh(qca->net_dev);
274 dev_kfree_skb(qca->txr.skb[qca->txr.head]);
275 qca->txr.skb[qca->txr.head] = NULL;
276 qca->txr.size -= pkt_len;
277 new_head = qca->txr.head + 1;
278 if (new_head >= qca->txr.count)
279 new_head = 0;
280 qca->txr.head = new_head;
281 if (netif_queue_stopped(qca->net_dev))
282 netif_wake_queue(qca->net_dev);
283 netif_tx_unlock_bh(qca->net_dev);
284 }
285
286 return 0;
287 }
288
289 static int
qcaspi_receive(struct qcaspi * qca)290 qcaspi_receive(struct qcaspi *qca)
291 {
292 struct net_device *net_dev = qca->net_dev;
293 struct net_device_stats *n_stats = &net_dev->stats;
294 u16 available = 0;
295 u32 bytes_read;
296 u8 *cp;
297
298 /* Allocate rx SKB if we don't have one available. */
299 if (!qca->rx_skb) {
300 qca->rx_skb = netdev_alloc_skb(net_dev,
301 net_dev->mtu + 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(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
qcaspi_tx_ring_has_space(struct tx_ring * txr)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
qcaspi_flush_tx_ring(struct qcaspi * qca)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
qcaspi_qca7k_sync(struct qcaspi * qca,int event)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
qcaspi_spi_thread(void * data)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 occured
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
qcaspi_intr_handler(int irq,void * data)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
qcaspi_netdev_open(struct net_device * dev)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
qcaspi_netdev_close(struct net_device * dev)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
qcaspi_netdev_xmit(struct sk_buff * skb,struct net_device * dev)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 dev->trans_start = jiffies;
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
qcaspi_netdev_tx_timeout(struct net_device * dev)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);
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
qcaspi_netdev_init(struct net_device * dev)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(dev, qca->net_dev->mtu + VLAN_ETH_HLEN);
764 if (!qca->rx_skb) {
765 kfree(qca->rx_buffer);
766 netdev_info(qca->net_dev, "Failed to allocate RX sk_buff.\n");
767 return -ENOBUFS;
768 }
769
770 return 0;
771 }
772
773 static void
qcaspi_netdev_uninit(struct net_device * dev)774 qcaspi_netdev_uninit(struct net_device *dev)
775 {
776 struct qcaspi *qca = netdev_priv(dev);
777
778 kfree(qca->rx_buffer);
779 qca->buffer_size = 0;
780 if (qca->rx_skb)
781 dev_kfree_skb(qca->rx_skb);
782 }
783
784 static int
qcaspi_netdev_change_mtu(struct net_device * dev,int new_mtu)785 qcaspi_netdev_change_mtu(struct net_device *dev, int new_mtu)
786 {
787 if ((new_mtu < QCAFRM_ETHMINMTU) || (new_mtu > QCAFRM_ETHMAXMTU))
788 return -EINVAL;
789
790 dev->mtu = new_mtu;
791
792 return 0;
793 }
794
795 static const struct net_device_ops qcaspi_netdev_ops = {
796 .ndo_init = qcaspi_netdev_init,
797 .ndo_uninit = qcaspi_netdev_uninit,
798 .ndo_open = qcaspi_netdev_open,
799 .ndo_stop = qcaspi_netdev_close,
800 .ndo_start_xmit = qcaspi_netdev_xmit,
801 .ndo_change_mtu = qcaspi_netdev_change_mtu,
802 .ndo_set_mac_address = eth_mac_addr,
803 .ndo_tx_timeout = qcaspi_netdev_tx_timeout,
804 .ndo_validate_addr = eth_validate_addr,
805 };
806
807 static void
qcaspi_netdev_setup(struct net_device * dev)808 qcaspi_netdev_setup(struct net_device *dev)
809 {
810 struct qcaspi *qca = NULL;
811
812 dev->netdev_ops = &qcaspi_netdev_ops;
813 qcaspi_set_ethtool_ops(dev);
814 dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
815 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
816 dev->tx_queue_len = 100;
817
818 qca = netdev_priv(dev);
819 memset(qca, 0, sizeof(struct qcaspi));
820
821 memset(&qca->spi_xfer1, 0, sizeof(struct spi_transfer));
822 memset(&qca->spi_xfer2, 0, sizeof(struct spi_transfer) * 2);
823
824 spi_message_init(&qca->spi_msg1);
825 spi_message_add_tail(&qca->spi_xfer1, &qca->spi_msg1);
826
827 spi_message_init(&qca->spi_msg2);
828 spi_message_add_tail(&qca->spi_xfer2[0], &qca->spi_msg2);
829 spi_message_add_tail(&qca->spi_xfer2[1], &qca->spi_msg2);
830
831 memset(&qca->txr, 0, sizeof(qca->txr));
832 qca->txr.count = TX_RING_MAX_LEN;
833 }
834
835 static const struct of_device_id qca_spi_of_match[] = {
836 { .compatible = "qca,qca7000" },
837 { /* sentinel */ }
838 };
839 MODULE_DEVICE_TABLE(of, qca_spi_of_match);
840
841 static int
qca_spi_probe(struct spi_device * spi_device)842 qca_spi_probe(struct spi_device *spi_device)
843 {
844 struct qcaspi *qca = NULL;
845 struct net_device *qcaspi_devs = NULL;
846 u8 legacy_mode = 0;
847 u16 signature;
848 const char *mac;
849
850 if (!spi_device->dev.of_node) {
851 dev_err(&spi_device->dev, "Missing device tree\n");
852 return -EINVAL;
853 }
854
855 legacy_mode = of_property_read_bool(spi_device->dev.of_node,
856 "qca,legacy-mode");
857
858 if (qcaspi_clkspeed == 0) {
859 if (spi_device->max_speed_hz)
860 qcaspi_clkspeed = spi_device->max_speed_hz;
861 else
862 qcaspi_clkspeed = QCASPI_CLK_SPEED;
863 }
864
865 if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
866 (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
867 dev_info(&spi_device->dev, "Invalid clkspeed: %d\n",
868 qcaspi_clkspeed);
869 return -EINVAL;
870 }
871
872 if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
873 (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
874 dev_info(&spi_device->dev, "Invalid burst len: %d\n",
875 qcaspi_burst_len);
876 return -EINVAL;
877 }
878
879 if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
880 (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
881 dev_info(&spi_device->dev, "Invalid pluggable: %d\n",
882 qcaspi_pluggable);
883 return -EINVAL;
884 }
885
886 dev_info(&spi_device->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
887 QCASPI_DRV_VERSION,
888 qcaspi_clkspeed,
889 qcaspi_burst_len,
890 qcaspi_pluggable);
891
892 spi_device->mode = SPI_MODE_3;
893 spi_device->max_speed_hz = qcaspi_clkspeed;
894 if (spi_setup(spi_device) < 0) {
895 dev_err(&spi_device->dev, "Unable to setup SPI device\n");
896 return -EFAULT;
897 }
898
899 qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
900 if (!qcaspi_devs)
901 return -ENOMEM;
902
903 qcaspi_netdev_setup(qcaspi_devs);
904
905 qca = netdev_priv(qcaspi_devs);
906 if (!qca) {
907 free_netdev(qcaspi_devs);
908 dev_err(&spi_device->dev, "Fail to retrieve private structure\n");
909 return -ENOMEM;
910 }
911 qca->net_dev = qcaspi_devs;
912 qca->spi_dev = spi_device;
913 qca->legacy_mode = legacy_mode;
914
915 mac = of_get_mac_address(spi_device->dev.of_node);
916
917 if (mac)
918 ether_addr_copy(qca->net_dev->dev_addr, mac);
919
920 if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
921 eth_hw_addr_random(qca->net_dev);
922 dev_info(&spi_device->dev, "Using random MAC address: %pM\n",
923 qca->net_dev->dev_addr);
924 }
925
926 netif_carrier_off(qca->net_dev);
927
928 if (!qcaspi_pluggable) {
929 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
930 qcaspi_read_register(qca, SPI_REG_SIGNATURE, &signature);
931
932 if (signature != QCASPI_GOOD_SIGNATURE) {
933 dev_err(&spi_device->dev, "Invalid signature (0x%04X)\n",
934 signature);
935 free_netdev(qcaspi_devs);
936 return -EFAULT;
937 }
938 }
939
940 if (register_netdev(qcaspi_devs)) {
941 dev_info(&spi_device->dev, "Unable to register net device %s\n",
942 qcaspi_devs->name);
943 free_netdev(qcaspi_devs);
944 return -EFAULT;
945 }
946
947 spi_set_drvdata(spi_device, qcaspi_devs);
948
949 qcaspi_init_device_debugfs(qca);
950
951 return 0;
952 }
953
954 static int
qca_spi_remove(struct spi_device * spi_device)955 qca_spi_remove(struct spi_device *spi_device)
956 {
957 struct net_device *qcaspi_devs = spi_get_drvdata(spi_device);
958 struct qcaspi *qca = netdev_priv(qcaspi_devs);
959
960 qcaspi_remove_device_debugfs(qca);
961
962 unregister_netdev(qcaspi_devs);
963 free_netdev(qcaspi_devs);
964
965 return 0;
966 }
967
968 static const struct spi_device_id qca_spi_id[] = {
969 { "qca7000", 0 },
970 { /* sentinel */ }
971 };
972 MODULE_DEVICE_TABLE(spi, qca_spi_id);
973
974 static struct spi_driver qca_spi_driver = {
975 .driver = {
976 .name = QCASPI_DRV_NAME,
977 .owner = THIS_MODULE,
978 .of_match_table = qca_spi_of_match,
979 },
980 .id_table = qca_spi_id,
981 .probe = qca_spi_probe,
982 .remove = qca_spi_remove,
983 };
984 module_spi_driver(qca_spi_driver);
985
986 MODULE_DESCRIPTION("Qualcomm Atheros SPI Driver");
987 MODULE_AUTHOR("Qualcomm Atheros Communications");
988 MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
989 MODULE_LICENSE("Dual BSD/GPL");
990 MODULE_VERSION(QCASPI_DRV_VERSION);
991