1// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
2/*
3 * Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
4 * Copyright (c) 2014, I2SE GmbH
5 */
6
7/* This module implements the Qualcomm Atheros SPI protocol for
8 * kernel-based SPI device; it is essentially an Ethernet-to-SPI
9 * serial converter;
10 */
11
12#include <linux/errno.h>
13#include <linux/etherdevice.h>
14#include <linux/if_arp.h>
15#include <linux/if_ether.h>
16#include <linux/init.h>
17#include <linux/interrupt.h>
18#include <linux/jiffies.h>
19#include <linux/kernel.h>
20#include <linux/kthread.h>
21#include <linux/module.h>
22#include <linux/moduleparam.h>
23#include <linux/netdevice.h>
24#include <linux/of.h>
25#include <linux/of_net.h>
26#include <linux/sched.h>
27#include <linux/skbuff.h>
28#include <linux/spi/spi.h>
29#include <linux/types.h>
30
31#include "qca_7k.h"
32#include "qca_7k_common.h"
33#include "qca_debug.h"
34#include "qca_spi.h"
35
36#define MAX_DMA_BURST_LEN 5000
37
38/* Modules parameters */
39#define QCASPI_CLK_SPEED_MIN 1000000
40#define QCASPI_CLK_SPEED_MAX 16000000
41#define QCASPI_CLK_SPEED 8000000
42static int qcaspi_clkspeed;
43module_param(qcaspi_clkspeed, int, 0);
44MODULE_PARM_DESC(qcaspi_clkspeed, "SPI bus clock speed (Hz). Use 1000000-16000000.");
45
46#define QCASPI_BURST_LEN_MIN 1
47#define QCASPI_BURST_LEN_MAX MAX_DMA_BURST_LEN
48static int qcaspi_burst_len = MAX_DMA_BURST_LEN;
49module_param(qcaspi_burst_len, int, 0);
50MODULE_PARM_DESC(qcaspi_burst_len, "Number of data bytes per burst. Use 1-5000.");
51
52#define QCASPI_PLUGGABLE_MIN 0
53#define QCASPI_PLUGGABLE_MAX 1
54static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;
55module_param(qcaspi_pluggable, int, 0);
56MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");
57
58#define QCASPI_WRITE_VERIFY_MIN 0
59#define QCASPI_WRITE_VERIFY_MAX 3
60static int wr_verify = QCASPI_WRITE_VERIFY_MIN;
61module_param(wr_verify, int, 0);
62MODULE_PARM_DESC(wr_verify, "SPI register write verify trails. Use 0-3.");
63
64#define QCASPI_TX_TIMEOUT (1 * HZ)
65#define QCASPI_QCA7K_REBOOT_TIME_MS 1000
66
67static void
68start_spi_intr_handling(struct qcaspi *qca, u16 *intr_cause)
69{
70 *intr_cause = 0;
71
72 qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, value: 0, retry: wr_verify);
73 qcaspi_read_register(qca, SPI_REG_INTR_CAUSE, result: intr_cause);
74 netdev_dbg(qca->net_dev, "interrupts: 0x%04x\n", *intr_cause);
75}
76
77static void
78end_spi_intr_handling(struct qcaspi *qca, u16 intr_cause)
79{
80 u16 intr_enable = (SPI_INT_CPU_ON |
81 SPI_INT_PKT_AVLBL |
82 SPI_INT_RDBUF_ERR |
83 SPI_INT_WRBUF_ERR);
84
85 qcaspi_write_register(qca, SPI_REG_INTR_CAUSE, value: intr_cause, retry: 0);
86 qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, value: intr_enable, retry: wr_verify);
87 netdev_dbg(qca->net_dev, "acking int: 0x%04x\n", intr_cause);
88}
89
90static u32
91qcaspi_write_burst(struct qcaspi *qca, u8 *src, u32 len)
92{
93 __be16 cmd;
94 struct spi_message msg;
95 struct spi_transfer transfer[2];
96 int ret;
97
98 memset(&transfer, 0, sizeof(transfer));
99 spi_message_init(m: &msg);
100
101 cmd = cpu_to_be16(QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
102 transfer[0].tx_buf = &cmd;
103 transfer[0].len = QCASPI_CMD_LEN;
104 transfer[1].tx_buf = src;
105 transfer[1].len = len;
106
107 spi_message_add_tail(t: &transfer[0], m: &msg);
108 spi_message_add_tail(t: &transfer[1], m: &msg);
109 ret = spi_sync(spi: qca->spi_dev, message: &msg);
110
111 if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {
112 qcaspi_spi_error(qca);
113 return 0;
114 }
115
116 return len;
117}
118
119static u32
120qcaspi_write_legacy(struct qcaspi *qca, u8 *src, u32 len)
121{
122 struct spi_message msg;
123 struct spi_transfer transfer;
124 int ret;
125
126 memset(&transfer, 0, sizeof(transfer));
127 spi_message_init(m: &msg);
128
129 transfer.tx_buf = src;
130 transfer.len = len;
131
132 spi_message_add_tail(t: &transfer, m: &msg);
133 ret = spi_sync(spi: qca->spi_dev, message: &msg);
134
135 if (ret || (msg.actual_length != len)) {
136 qcaspi_spi_error(qca);
137 return 0;
138 }
139
140 return len;
141}
142
143static u32
144qcaspi_read_burst(struct qcaspi *qca, u8 *dst, u32 len)
145{
146 struct spi_message msg;
147 __be16 cmd;
148 struct spi_transfer transfer[2];
149 int ret;
150
151 memset(&transfer, 0, sizeof(transfer));
152 spi_message_init(m: &msg);
153
154 cmd = cpu_to_be16(QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
155 transfer[0].tx_buf = &cmd;
156 transfer[0].len = QCASPI_CMD_LEN;
157 transfer[1].rx_buf = dst;
158 transfer[1].len = len;
159
160 spi_message_add_tail(t: &transfer[0], m: &msg);
161 spi_message_add_tail(t: &transfer[1], m: &msg);
162 ret = spi_sync(spi: qca->spi_dev, message: &msg);
163
164 if (ret || (msg.actual_length != QCASPI_CMD_LEN + len)) {
165 qcaspi_spi_error(qca);
166 return 0;
167 }
168
169 return len;
170}
171
172static u32
173qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)
174{
175 struct spi_message msg;
176 struct spi_transfer transfer;
177 int ret;
178
179 memset(&transfer, 0, sizeof(transfer));
180 spi_message_init(m: &msg);
181
182 transfer.rx_buf = dst;
183 transfer.len = len;
184
185 spi_message_add_tail(t: &transfer, m: &msg);
186 ret = spi_sync(spi: qca->spi_dev, message: &msg);
187
188 if (ret || (msg.actual_length != len)) {
189 qcaspi_spi_error(qca);
190 return 0;
191 }
192
193 return len;
194}
195
196static int
197qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd)
198{
199 __be16 tx_data;
200 struct spi_message msg;
201 struct spi_transfer transfer;
202 int ret;
203
204 memset(&transfer, 0, sizeof(transfer));
205
206 spi_message_init(m: &msg);
207
208 tx_data = cpu_to_be16(cmd);
209 transfer.len = sizeof(cmd);
210 transfer.tx_buf = &tx_data;
211 spi_message_add_tail(t: &transfer, m: &msg);
212
213 ret = spi_sync(spi: qca->spi_dev, message: &msg);
214
215 if (!ret)
216 ret = msg.status;
217
218 if (ret)
219 qcaspi_spi_error(qca);
220
221 return ret;
222}
223
224static int
225qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
226{
227 u32 count;
228 u32 written;
229 u32 offset;
230 u32 len;
231
232 len = skb->len;
233
234 qcaspi_write_register(qca, SPI_REG_BFR_SIZE, value: len, retry: wr_verify);
235 if (qca->legacy_mode)
236 qcaspi_tx_cmd(qca, QCA7K_SPI_WRITE | QCA7K_SPI_EXTERNAL);
237
238 offset = 0;
239 while (len) {
240 count = len;
241 if (count > qca->burst_len)
242 count = qca->burst_len;
243
244 if (qca->legacy_mode) {
245 written = qcaspi_write_legacy(qca,
246 src: skb->data + offset,
247 len: count);
248 } else {
249 written = qcaspi_write_burst(qca,
250 src: skb->data + offset,
251 len: count);
252 }
253
254 if (written != count)
255 return -1;
256
257 offset += count;
258 len -= count;
259 }
260
261 return 0;
262}
263
264static int
265qcaspi_transmit(struct qcaspi *qca)
266{
267 struct net_device_stats *n_stats = &qca->net_dev->stats;
268 u16 available = 0;
269 u32 pkt_len;
270 u16 new_head;
271 u16 packets = 0;
272
273 if (qca->txr.skb[qca->txr.head] == NULL)
274 return 0;
275
276 qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA, result: &available);
277
278 if (available > QCASPI_HW_BUF_LEN) {
279 /* This could only happen by interferences on the SPI line.
280 * So retry later ...
281 */
282 qca->stats.buf_avail_err++;
283 return -1;
284 }
285
286 while (qca->txr.skb[qca->txr.head]) {
287 pkt_len = qca->txr.skb[qca->txr.head]->len + QCASPI_HW_PKT_LEN;
288
289 if (available < pkt_len) {
290 if (packets == 0)
291 qca->stats.write_buf_miss++;
292 break;
293 }
294
295 if (qcaspi_tx_frame(qca, skb: qca->txr.skb[qca->txr.head]) == -1) {
296 qca->stats.write_err++;
297 return -1;
298 }
299
300 packets++;
301 n_stats->tx_packets++;
302 n_stats->tx_bytes += qca->txr.skb[qca->txr.head]->len;
303 available -= pkt_len;
304
305 /* remove the skb from the queue */
306 /* XXX After inconsistent lock states netif_tx_lock()
307 * has been replaced by netif_tx_lock_bh() and so on.
308 */
309 netif_tx_lock_bh(dev: qca->net_dev);
310 dev_kfree_skb(qca->txr.skb[qca->txr.head]);
311 qca->txr.skb[qca->txr.head] = NULL;
312 qca->txr.size -= pkt_len;
313 new_head = qca->txr.head + 1;
314 if (new_head >= qca->txr.count)
315 new_head = 0;
316 qca->txr.head = new_head;
317 if (netif_queue_stopped(dev: qca->net_dev))
318 netif_wake_queue(dev: qca->net_dev);
319 netif_tx_unlock_bh(dev: qca->net_dev);
320 }
321
322 return 0;
323}
324
325static int
326qcaspi_receive(struct qcaspi *qca)
327{
328 struct net_device *net_dev = qca->net_dev;
329 struct net_device_stats *n_stats = &net_dev->stats;
330 u16 available = 0;
331 u32 bytes_read;
332 u8 *cp;
333
334 /* Allocate rx SKB if we don't have one available. */
335 if (!qca->rx_skb) {
336 qca->rx_skb = netdev_alloc_skb_ip_align(dev: net_dev,
337 length: net_dev->mtu +
338 VLAN_ETH_HLEN);
339 if (!qca->rx_skb) {
340 netdev_dbg(net_dev, "out of RX resources\n");
341 qca->stats.out_of_mem++;
342 return -1;
343 }
344 }
345
346 /* Read the packet size. */
347 qcaspi_read_register(qca, SPI_REG_RDBUF_BYTE_AVA, result: &available);
348
349 netdev_dbg(net_dev, "qcaspi_receive: SPI_REG_RDBUF_BYTE_AVA: Value: %04x\n",
350 available);
351
352 if (available > QCASPI_HW_BUF_LEN + QCASPI_HW_PKT_LEN) {
353 /* This could only happen by interferences on the SPI line.
354 * So retry later ...
355 */
356 qca->stats.buf_avail_err++;
357 return -1;
358 } else if (available == 0) {
359 netdev_dbg(net_dev, "qcaspi_receive called without any data being available!\n");
360 return -1;
361 }
362
363 qcaspi_write_register(qca, SPI_REG_BFR_SIZE, value: available, retry: wr_verify);
364
365 if (qca->legacy_mode)
366 qcaspi_tx_cmd(qca, QCA7K_SPI_READ | QCA7K_SPI_EXTERNAL);
367
368 while (available) {
369 u32 count = available;
370
371 if (count > qca->burst_len)
372 count = qca->burst_len;
373
374 if (qca->legacy_mode) {
375 bytes_read = qcaspi_read_legacy(qca, dst: qca->rx_buffer,
376 len: count);
377 } else {
378 bytes_read = qcaspi_read_burst(qca, dst: qca->rx_buffer,
379 len: count);
380 }
381
382 netdev_dbg(net_dev, "available: %d, byte read: %d\n",
383 available, bytes_read);
384
385 if (bytes_read) {
386 available -= bytes_read;
387 } else {
388 qca->stats.read_err++;
389 return -1;
390 }
391
392 cp = qca->rx_buffer;
393
394 while ((bytes_read--) && (qca->rx_skb)) {
395 s32 retcode;
396
397 retcode = qcafrm_fsm_decode(handle: &qca->frm_handle,
398 buf: qca->rx_skb->data,
399 buf_len: skb_tailroom(skb: qca->rx_skb),
400 recv_byte: *cp);
401 cp++;
402 switch (retcode) {
403 case QCAFRM_GATHER:
404 case QCAFRM_NOHEAD:
405 break;
406 case QCAFRM_NOTAIL:
407 netdev_dbg(net_dev, "no RX tail\n");
408 n_stats->rx_errors++;
409 n_stats->rx_dropped++;
410 break;
411 case QCAFRM_INVLEN:
412 netdev_dbg(net_dev, "invalid RX length\n");
413 n_stats->rx_errors++;
414 n_stats->rx_dropped++;
415 break;
416 default:
417 qca->rx_skb->dev = qca->net_dev;
418 n_stats->rx_packets++;
419 n_stats->rx_bytes += retcode;
420 skb_put(skb: qca->rx_skb, len: retcode);
421 qca->rx_skb->protocol = eth_type_trans(
422 skb: qca->rx_skb, dev: qca->rx_skb->dev);
423 skb_checksum_none_assert(skb: qca->rx_skb);
424 netif_rx(skb: qca->rx_skb);
425 qca->rx_skb = netdev_alloc_skb_ip_align(dev: net_dev,
426 length: net_dev->mtu + VLAN_ETH_HLEN);
427 if (!qca->rx_skb) {
428 netdev_dbg(net_dev, "out of RX resources\n");
429 n_stats->rx_errors++;
430 qca->stats.out_of_mem++;
431 break;
432 }
433 }
434 }
435 }
436
437 return 0;
438}
439
440/* Check that tx ring stores only so much bytes
441 * that fit into the internal QCA buffer.
442 */
443
444static int
445qcaspi_tx_ring_has_space(struct tx_ring *txr)
446{
447 if (txr->skb[txr->tail])
448 return 0;
449
450 return (txr->size + QCAFRM_MAX_LEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
451}
452
453/* Flush the tx ring. This function is only safe to
454 * call from the qcaspi_spi_thread.
455 */
456
457static void
458qcaspi_flush_tx_ring(struct qcaspi *qca)
459{
460 int i;
461
462 /* XXX After inconsistent lock states netif_tx_lock()
463 * has been replaced by netif_tx_lock_bh() and so on.
464 */
465 netif_tx_lock_bh(dev: qca->net_dev);
466 for (i = 0; i < QCASPI_TX_RING_MAX_LEN; i++) {
467 if (qca->txr.skb[i]) {
468 dev_kfree_skb(qca->txr.skb[i]);
469 qca->txr.skb[i] = NULL;
470 qca->net_dev->stats.tx_dropped++;
471 }
472 }
473 qca->txr.tail = 0;
474 qca->txr.head = 0;
475 qca->txr.size = 0;
476 netif_tx_unlock_bh(dev: qca->net_dev);
477}
478
479static void
480qcaspi_qca7k_sync(struct qcaspi *qca, int event)
481{
482 u16 signature = 0;
483 u16 spi_config;
484 u16 wrbuf_space = 0;
485
486 if (event == QCASPI_EVENT_CPUON) {
487 /* Read signature twice, if not valid
488 * go back to unknown state.
489 */
490 qcaspi_read_register(qca, SPI_REG_SIGNATURE, result: &signature);
491 qcaspi_read_register(qca, SPI_REG_SIGNATURE, result: &signature);
492 if (signature != QCASPI_GOOD_SIGNATURE) {
493 if (qca->sync == QCASPI_SYNC_READY)
494 qca->stats.bad_signature++;
495
496 qca->sync = QCASPI_SYNC_UNKNOWN;
497 netdev_dbg(qca->net_dev, "sync: got CPU on, but signature was invalid, restart\n");
498 return;
499 } else {
500 /* ensure that the WRBUF is empty */
501 qcaspi_read_register(qca, SPI_REG_WRBUF_SPC_AVA,
502 result: &wrbuf_space);
503 if (wrbuf_space != QCASPI_HW_BUF_LEN) {
504 netdev_dbg(qca->net_dev, "sync: got CPU on, but wrbuf not empty. reset!\n");
505 qca->sync = QCASPI_SYNC_UNKNOWN;
506 } else {
507 netdev_dbg(qca->net_dev, "sync: got CPU on, now in sync\n");
508 qca->sync = QCASPI_SYNC_READY;
509 return;
510 }
511 }
512 }
513
514 switch (qca->sync) {
515 case QCASPI_SYNC_READY:
516 /* Check signature twice, if not valid go to unknown state. */
517 qcaspi_read_register(qca, SPI_REG_SIGNATURE, result: &signature);
518 if (signature != QCASPI_GOOD_SIGNATURE)
519 qcaspi_read_register(qca, SPI_REG_SIGNATURE, result: &signature);
520
521 if (signature != QCASPI_GOOD_SIGNATURE) {
522 qca->sync = QCASPI_SYNC_UNKNOWN;
523 qca->stats.bad_signature++;
524 netdev_dbg(qca->net_dev, "sync: bad signature, restart\n");
525 /* don't reset right away */
526 return;
527 }
528 break;
529 case QCASPI_SYNC_UNKNOWN:
530 /* Read signature, if not valid stay in unknown state */
531 qcaspi_read_register(qca, SPI_REG_SIGNATURE, result: &signature);
532 if (signature != QCASPI_GOOD_SIGNATURE) {
533 netdev_dbg(qca->net_dev, "sync: could not read signature to reset device, retry.\n");
534 return;
535 }
536
537 /* TODO: use GPIO to reset QCA7000 in legacy mode*/
538 netdev_dbg(qca->net_dev, "sync: resetting device.\n");
539 qcaspi_read_register(qca, SPI_REG_SPI_CONFIG, result: &spi_config);
540 spi_config |= QCASPI_SLAVE_RESET_BIT;
541 qcaspi_write_register(qca, SPI_REG_SPI_CONFIG, value: spi_config, retry: 0);
542
543 qca->sync = QCASPI_SYNC_RESET;
544 qca->stats.trig_reset++;
545 qca->reset_count = 0;
546 break;
547 case QCASPI_SYNC_RESET:
548 qca->reset_count++;
549 netdev_dbg(qca->net_dev, "sync: waiting for CPU on, count %u.\n",
550 qca->reset_count);
551 if (qca->reset_count >= QCASPI_RESET_TIMEOUT) {
552 /* reset did not seem to take place, try again */
553 qca->sync = QCASPI_SYNC_UNKNOWN;
554 qca->stats.reset_timeout++;
555 netdev_dbg(qca->net_dev, "sync: reset timeout, restarting process.\n");
556 }
557 break;
558 }
559}
560
561static int
562qcaspi_spi_thread(void *data)
563{
564 struct qcaspi *qca = data;
565 u16 intr_cause = 0;
566
567 netdev_info(dev: qca->net_dev, format: "SPI thread created\n");
568 while (!kthread_should_stop()) {
569 set_current_state(TASK_INTERRUPTIBLE);
570 if (kthread_should_park()) {
571 netif_tx_disable(dev: qca->net_dev);
572 netif_carrier_off(dev: qca->net_dev);
573 qcaspi_flush_tx_ring(qca);
574 kthread_parkme();
575 if (qca->sync == QCASPI_SYNC_READY) {
576 netif_carrier_on(dev: qca->net_dev);
577 netif_wake_queue(dev: qca->net_dev);
578 }
579 continue;
580 }
581
582 if ((qca->intr_req == qca->intr_svc) &&
583 !qca->txr.skb[qca->txr.head])
584 schedule();
585
586 set_current_state(TASK_RUNNING);
587
588 netdev_dbg(qca->net_dev, "have work to do. int: %d, tx_skb: %p\n",
589 qca->intr_req - qca->intr_svc,
590 qca->txr.skb[qca->txr.head]);
591
592 qcaspi_qca7k_sync(qca, QCASPI_EVENT_UPDATE);
593
594 if (qca->sync != QCASPI_SYNC_READY) {
595 netdev_dbg(qca->net_dev, "sync: not ready %u, turn off carrier and flush\n",
596 (unsigned int)qca->sync);
597 netif_stop_queue(dev: qca->net_dev);
598 netif_carrier_off(dev: qca->net_dev);
599 qcaspi_flush_tx_ring(qca);
600 msleep(QCASPI_QCA7K_REBOOT_TIME_MS);
601 }
602
603 if (qca->intr_svc != qca->intr_req) {
604 qca->intr_svc = qca->intr_req;
605 start_spi_intr_handling(qca, intr_cause: &intr_cause);
606
607 if (intr_cause & SPI_INT_CPU_ON) {
608 qcaspi_qca7k_sync(qca, QCASPI_EVENT_CPUON);
609
610 /* Frame decoding in progress */
611 if (qca->frm_handle.state != qca->frm_handle.init)
612 qca->net_dev->stats.rx_dropped++;
613
614 qcafrm_fsm_init_spi(handle: &qca->frm_handle);
615 qca->stats.device_reset++;
616
617 /* not synced. */
618 if (qca->sync != QCASPI_SYNC_READY)
619 continue;
620
621 netif_wake_queue(dev: qca->net_dev);
622 netif_carrier_on(dev: qca->net_dev);
623 }
624
625 if (intr_cause & SPI_INT_RDBUF_ERR) {
626 /* restart sync */
627 netdev_dbg(qca->net_dev, "===> rdbuf error!\n");
628 qca->stats.read_buf_err++;
629 qca->sync = QCASPI_SYNC_UNKNOWN;
630 continue;
631 }
632
633 if (intr_cause & SPI_INT_WRBUF_ERR) {
634 /* restart sync */
635 netdev_dbg(qca->net_dev, "===> wrbuf error!\n");
636 qca->stats.write_buf_err++;
637 qca->sync = QCASPI_SYNC_UNKNOWN;
638 continue;
639 }
640
641 /* can only handle other interrupts
642 * if sync has occurred
643 */
644 if (qca->sync == QCASPI_SYNC_READY) {
645 if (intr_cause & SPI_INT_PKT_AVLBL)
646 qcaspi_receive(qca);
647 }
648
649 end_spi_intr_handling(qca, intr_cause);
650 }
651
652 if (qca->sync == QCASPI_SYNC_READY)
653 qcaspi_transmit(qca);
654 }
655 set_current_state(TASK_RUNNING);
656 netdev_info(dev: qca->net_dev, format: "SPI thread exit\n");
657
658 return 0;
659}
660
661static irqreturn_t
662qcaspi_intr_handler(int irq, void *data)
663{
664 struct qcaspi *qca = data;
665
666 qca->intr_req++;
667 if (qca->spi_thread)
668 wake_up_process(tsk: qca->spi_thread);
669
670 return IRQ_HANDLED;
671}
672
673static int
674qcaspi_netdev_open(struct net_device *dev)
675{
676 struct qcaspi *qca = netdev_priv(dev);
677 struct task_struct *thread;
678
679 if (!qca)
680 return -EINVAL;
681
682 qca->intr_req = 1;
683 qca->intr_svc = 0;
684 qca->sync = QCASPI_SYNC_UNKNOWN;
685 qcafrm_fsm_init_spi(handle: &qca->frm_handle);
686
687 thread = kthread_run((void *)qcaspi_spi_thread,
688 qca, "%s", dev->name);
689
690 if (IS_ERR(ptr: thread)) {
691 netdev_err(dev, format: "%s: unable to start kernel thread.\n",
692 QCASPI_DRV_NAME);
693 return PTR_ERR(ptr: thread);
694 }
695
696 qca->spi_thread = thread;
697
698 enable_irq(irq: qca->spi_dev->irq);
699
700 /* SPI thread takes care of TX queue */
701
702 return 0;
703}
704
705static int
706qcaspi_netdev_close(struct net_device *dev)
707{
708 struct qcaspi *qca = netdev_priv(dev);
709
710 netif_stop_queue(dev);
711
712 qcaspi_write_register(qca, SPI_REG_INTR_ENABLE, value: 0, retry: wr_verify);
713 disable_irq(irq: qca->spi_dev->irq);
714
715 if (qca->spi_thread) {
716 kthread_stop(k: qca->spi_thread);
717 qca->spi_thread = NULL;
718 }
719 qcaspi_flush_tx_ring(qca);
720
721 return 0;
722}
723
724static netdev_tx_t
725qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
726{
727 u32 frame_len;
728 u8 *ptmp;
729 struct qcaspi *qca = netdev_priv(dev);
730 u16 new_tail;
731 struct sk_buff *tskb;
732 u8 pad_len = 0;
733
734 if (skb->len < QCAFRM_MIN_LEN)
735 pad_len = QCAFRM_MIN_LEN - skb->len;
736
737 if (qca->txr.skb[qca->txr.tail]) {
738 netdev_warn(dev: qca->net_dev, format: "queue was unexpectedly full!\n");
739 netif_stop_queue(dev: qca->net_dev);
740 qca->stats.ring_full++;
741 return NETDEV_TX_BUSY;
742 }
743
744 if ((skb_headroom(skb) < QCAFRM_HEADER_LEN) ||
745 (skb_tailroom(skb) < QCAFRM_FOOTER_LEN + pad_len)) {
746 tskb = skb_copy_expand(skb, QCAFRM_HEADER_LEN,
747 QCAFRM_FOOTER_LEN + pad_len, GFP_ATOMIC);
748 if (!tskb) {
749 qca->stats.out_of_mem++;
750 return NETDEV_TX_BUSY;
751 }
752 dev_kfree_skb(skb);
753 skb = tskb;
754 }
755
756 frame_len = skb->len + pad_len;
757
758 ptmp = skb_push(skb, QCAFRM_HEADER_LEN);
759 qcafrm_create_header(buf: ptmp, len: frame_len);
760
761 if (pad_len) {
762 ptmp = skb_put_zero(skb, len: pad_len);
763 }
764
765 ptmp = skb_put(skb, QCAFRM_FOOTER_LEN);
766 qcafrm_create_footer(buf: ptmp);
767
768 netdev_dbg(qca->net_dev, "Tx-ing packet: Size: 0x%08x\n",
769 skb->len);
770
771 qca->txr.size += skb->len + QCASPI_HW_PKT_LEN;
772
773 new_tail = qca->txr.tail + 1;
774 if (new_tail >= qca->txr.count)
775 new_tail = 0;
776
777 qca->txr.skb[qca->txr.tail] = skb;
778 qca->txr.tail = new_tail;
779
780 if (!qcaspi_tx_ring_has_space(txr: &qca->txr)) {
781 netif_stop_queue(dev: qca->net_dev);
782 qca->stats.ring_full++;
783 }
784
785 netif_trans_update(dev);
786
787 if (qca->spi_thread)
788 wake_up_process(tsk: qca->spi_thread);
789
790 return NETDEV_TX_OK;
791}
792
793static void
794qcaspi_netdev_tx_timeout(struct net_device *dev, unsigned int txqueue)
795{
796 struct qcaspi *qca = netdev_priv(dev);
797
798 netdev_info(dev: qca->net_dev, format: "Transmit timeout at %ld, latency %ld\n",
799 jiffies, jiffies - dev_trans_start(dev));
800 qca->net_dev->stats.tx_errors++;
801 /* Trigger tx queue flush and QCA7000 reset */
802 qca->sync = QCASPI_SYNC_UNKNOWN;
803
804 if (qca->spi_thread)
805 wake_up_process(tsk: qca->spi_thread);
806}
807
808static int
809qcaspi_netdev_init(struct net_device *dev)
810{
811 struct qcaspi *qca = netdev_priv(dev);
812
813 dev->mtu = QCAFRM_MAX_MTU;
814 dev->type = ARPHRD_ETHER;
815 qca->clkspeed = qcaspi_clkspeed;
816 qca->burst_len = qcaspi_burst_len;
817 qca->spi_thread = NULL;
818 qca->buffer_size = (QCAFRM_MAX_MTU + VLAN_ETH_HLEN + QCAFRM_HEADER_LEN +
819 QCAFRM_FOOTER_LEN + QCASPI_HW_PKT_LEN) * QCASPI_RX_MAX_FRAMES;
820
821 memset(&qca->stats, 0, sizeof(struct qcaspi_stats));
822
823 qca->rx_buffer = kmalloc(size: qca->buffer_size, GFP_KERNEL);
824 if (!qca->rx_buffer)
825 return -ENOBUFS;
826
827 qca->rx_skb = netdev_alloc_skb_ip_align(dev, length: qca->net_dev->mtu +
828 VLAN_ETH_HLEN);
829 if (!qca->rx_skb) {
830 kfree(objp: qca->rx_buffer);
831 netdev_info(dev: qca->net_dev, format: "Failed to allocate RX sk_buff.\n");
832 return -ENOBUFS;
833 }
834
835 return 0;
836}
837
838static void
839qcaspi_netdev_uninit(struct net_device *dev)
840{
841 struct qcaspi *qca = netdev_priv(dev);
842
843 kfree(objp: qca->rx_buffer);
844 qca->buffer_size = 0;
845 dev_kfree_skb(qca->rx_skb);
846}
847
848static const struct net_device_ops qcaspi_netdev_ops = {
849 .ndo_init = qcaspi_netdev_init,
850 .ndo_uninit = qcaspi_netdev_uninit,
851 .ndo_open = qcaspi_netdev_open,
852 .ndo_stop = qcaspi_netdev_close,
853 .ndo_start_xmit = qcaspi_netdev_xmit,
854 .ndo_set_mac_address = eth_mac_addr,
855 .ndo_tx_timeout = qcaspi_netdev_tx_timeout,
856 .ndo_validate_addr = eth_validate_addr,
857};
858
859static void
860qcaspi_netdev_setup(struct net_device *dev)
861{
862 struct qcaspi *qca = NULL;
863
864 dev->netdev_ops = &qcaspi_netdev_ops;
865 qcaspi_set_ethtool_ops(dev);
866 dev->watchdog_timeo = QCASPI_TX_TIMEOUT;
867 dev->priv_flags &= ~IFF_TX_SKB_SHARING;
868 dev->needed_tailroom = ALIGN(QCAFRM_FOOTER_LEN + QCAFRM_MIN_LEN, 4);
869 dev->needed_headroom = ALIGN(QCAFRM_HEADER_LEN, 4);
870 dev->tx_queue_len = 100;
871
872 /* MTU range: 46 - 1500 */
873 dev->min_mtu = QCAFRM_MIN_MTU;
874 dev->max_mtu = QCAFRM_MAX_MTU;
875
876 qca = netdev_priv(dev);
877 memset(qca, 0, sizeof(struct qcaspi));
878
879 memset(&qca->txr, 0, sizeof(qca->txr));
880 qca->txr.count = QCASPI_TX_RING_MAX_LEN;
881}
882
883static const struct of_device_id qca_spi_of_match[] = {
884 { .compatible = "qca,qca7000" },
885 { /* sentinel */ }
886};
887MODULE_DEVICE_TABLE(of, qca_spi_of_match);
888
889static int
890qca_spi_probe(struct spi_device *spi)
891{
892 struct qcaspi *qca = NULL;
893 struct net_device *qcaspi_devs = NULL;
894 u8 legacy_mode = 0;
895 u16 signature;
896 int ret;
897
898 if (!spi->dev.of_node) {
899 dev_err(&spi->dev, "Missing device tree\n");
900 return -EINVAL;
901 }
902
903 legacy_mode = of_property_read_bool(np: spi->dev.of_node,
904 propname: "qca,legacy-mode");
905
906 if (qcaspi_clkspeed == 0) {
907 if (spi->max_speed_hz)
908 qcaspi_clkspeed = spi->max_speed_hz;
909 else
910 qcaspi_clkspeed = QCASPI_CLK_SPEED;
911 }
912
913 if ((qcaspi_clkspeed < QCASPI_CLK_SPEED_MIN) ||
914 (qcaspi_clkspeed > QCASPI_CLK_SPEED_MAX)) {
915 dev_err(&spi->dev, "Invalid clkspeed: %d\n",
916 qcaspi_clkspeed);
917 return -EINVAL;
918 }
919
920 if ((qcaspi_burst_len < QCASPI_BURST_LEN_MIN) ||
921 (qcaspi_burst_len > QCASPI_BURST_LEN_MAX)) {
922 dev_err(&spi->dev, "Invalid burst len: %d\n",
923 qcaspi_burst_len);
924 return -EINVAL;
925 }
926
927 if ((qcaspi_pluggable < QCASPI_PLUGGABLE_MIN) ||
928 (qcaspi_pluggable > QCASPI_PLUGGABLE_MAX)) {
929 dev_err(&spi->dev, "Invalid pluggable: %d\n",
930 qcaspi_pluggable);
931 return -EINVAL;
932 }
933
934 if (wr_verify < QCASPI_WRITE_VERIFY_MIN ||
935 wr_verify > QCASPI_WRITE_VERIFY_MAX) {
936 dev_err(&spi->dev, "Invalid write verify: %d\n",
937 wr_verify);
938 return -EINVAL;
939 }
940
941 dev_info(&spi->dev, "ver=%s, clkspeed=%d, burst_len=%d, pluggable=%d\n",
942 QCASPI_DRV_VERSION,
943 qcaspi_clkspeed,
944 qcaspi_burst_len,
945 qcaspi_pluggable);
946
947 spi->mode = SPI_MODE_3;
948 spi->max_speed_hz = qcaspi_clkspeed;
949 if (spi_setup(spi) < 0) {
950 dev_err(&spi->dev, "Unable to setup SPI device\n");
951 return -EFAULT;
952 }
953
954 qcaspi_devs = alloc_etherdev(sizeof(struct qcaspi));
955 if (!qcaspi_devs)
956 return -ENOMEM;
957
958 qcaspi_netdev_setup(dev: qcaspi_devs);
959 SET_NETDEV_DEV(qcaspi_devs, &spi->dev);
960
961 qca = netdev_priv(dev: qcaspi_devs);
962 if (!qca) {
963 free_netdev(dev: qcaspi_devs);
964 dev_err(&spi->dev, "Fail to retrieve private structure\n");
965 return -ENOMEM;
966 }
967 qca->net_dev = qcaspi_devs;
968 qca->spi_dev = spi;
969 qca->legacy_mode = legacy_mode;
970
971 spi_set_drvdata(spi, data: qcaspi_devs);
972
973 ret = devm_request_irq(dev: &spi->dev, irq: spi->irq, handler: qcaspi_intr_handler,
974 IRQF_NO_AUTOEN, devname: qca->net_dev->name, dev_id: qca);
975 if (ret) {
976 dev_err(&spi->dev, "Unable to get IRQ %d (irqval=%d).\n",
977 spi->irq, ret);
978 free_netdev(dev: qcaspi_devs);
979 return ret;
980 }
981
982 ret = of_get_ethdev_address(np: spi->dev.of_node, dev: qca->net_dev);
983 if (ret) {
984 eth_hw_addr_random(dev: qca->net_dev);
985 dev_info(&spi->dev, "Using random MAC address: %pM\n",
986 qca->net_dev->dev_addr);
987 }
988
989 netif_carrier_off(dev: qca->net_dev);
990
991 if (!qcaspi_pluggable) {
992 qcaspi_read_register(qca, SPI_REG_SIGNATURE, result: &signature);
993 qcaspi_read_register(qca, SPI_REG_SIGNATURE, result: &signature);
994
995 if (signature != QCASPI_GOOD_SIGNATURE) {
996 dev_err(&spi->dev, "Invalid signature (expected 0x%04x, read 0x%04x)\n",
997 QCASPI_GOOD_SIGNATURE, signature);
998 free_netdev(dev: qcaspi_devs);
999 return -EFAULT;
1000 }
1001 }
1002
1003 if (register_netdev(dev: qcaspi_devs)) {
1004 dev_err(&spi->dev, "Unable to register net device %s\n",
1005 qcaspi_devs->name);
1006 free_netdev(dev: qcaspi_devs);
1007 return -EFAULT;
1008 }
1009
1010 qcaspi_init_device_debugfs(qca);
1011
1012 return 0;
1013}
1014
1015static void
1016qca_spi_remove(struct spi_device *spi)
1017{
1018 struct net_device *qcaspi_devs = spi_get_drvdata(spi);
1019 struct qcaspi *qca = netdev_priv(dev: qcaspi_devs);
1020
1021 qcaspi_remove_device_debugfs(qca);
1022
1023 unregister_netdev(dev: qcaspi_devs);
1024 free_netdev(dev: qcaspi_devs);
1025}
1026
1027static const struct spi_device_id qca_spi_id[] = {
1028 { "qca7000", 0 },
1029 { /* sentinel */ }
1030};
1031MODULE_DEVICE_TABLE(spi, qca_spi_id);
1032
1033static struct spi_driver qca_spi_driver = {
1034 .driver = {
1035 .name = QCASPI_DRV_NAME,
1036 .of_match_table = qca_spi_of_match,
1037 },
1038 .id_table = qca_spi_id,
1039 .probe = qca_spi_probe,
1040 .remove = qca_spi_remove,
1041};
1042module_spi_driver(qca_spi_driver);
1043
1044MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 SPI Driver");
1045MODULE_AUTHOR("Qualcomm Atheros Communications");
1046MODULE_AUTHOR("Stefan Wahren <wahrenst@gmx.net>");
1047MODULE_LICENSE("Dual BSD/GPL");
1048MODULE_VERSION(QCASPI_DRV_VERSION);
1049

source code of linux/drivers/net/ethernet/qualcomm/qca_spi.c