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WIP FPC-III support
[linux/fpc-iii.git] / drivers / hsi / clients / ssi_protocol.c
blob96d0eccca3aa74a5871b386f5dc369735e58745b
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * ssi_protocol.c
4 *
5 * Implementation of the SSI McSAAB improved protocol.
6 *
7 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
8 * Copyright (C) 2013 Sebastian Reichel <sre@kernel.org>
9 *
10 * Contact: Carlos Chinea <carlos.chinea@nokia.com>
11 */
12
13 #include <linux/atomic.h>
14 #include <linux/clk.h>
15 #include <linux/device.h>
16 #include <linux/err.h>
17 #include <linux/gpio.h>
18 #include <linux/if_ether.h>
19 #include <linux/if_arp.h>
20 #include <linux/if_phonet.h>
21 #include <linux/init.h>
22 #include <linux/irq.h>
23 #include <linux/list.h>
24 #include <linux/module.h>
25 #include <linux/netdevice.h>
26 #include <linux/notifier.h>
27 #include <linux/scatterlist.h>
28 #include <linux/skbuff.h>
29 #include <linux/slab.h>
30 #include <linux/spinlock.h>
31 #include <linux/timer.h>
32 #include <linux/hsi/hsi.h>
33 #include <linux/hsi/ssi_protocol.h>
34
35 void ssi_waketest(struct hsi_client *cl, unsigned int enable);
36
37 #define SSIP_TXQUEUE_LEN 100
38 #define SSIP_MAX_MTU 65535
39 #define SSIP_DEFAULT_MTU 4000
40 #define PN_MEDIA_SOS 21
41 #define SSIP_MIN_PN_HDR 6 /* FIXME: Revisit */
42 #define SSIP_WDTOUT 2000 /* FIXME: has to be 500 msecs */
43 #define SSIP_KATOUT 15 /* 15 msecs */
44 #define SSIP_MAX_CMDS 5 /* Number of pre-allocated commands buffers */
45 #define SSIP_BYTES_TO_FRAMES(x) ((((x) - 1) >> 2) + 1)
46 #define SSIP_CMT_LOADER_SYNC 0x11223344
47 /*
48 * SSI protocol command definitions
49 */
50 #define SSIP_COMMAND(data) ((data) >> 28)
51 #define SSIP_PAYLOAD(data) ((data) & 0xfffffff)
52 /* Commands */
53 #define SSIP_SW_BREAK 0
54 #define SSIP_BOOTINFO_REQ 1
55 #define SSIP_BOOTINFO_RESP 2
56 #define SSIP_WAKETEST_RESULT 3
57 #define SSIP_START_TRANS 4
58 #define SSIP_READY 5
59 /* Payloads */
60 #define SSIP_DATA_VERSION(data) ((data) & 0xff)
61 #define SSIP_LOCAL_VERID 1
62 #define SSIP_WAKETEST_OK 0
63 #define SSIP_WAKETEST_FAILED 1
64 #define SSIP_PDU_LENGTH(data) (((data) >> 8) & 0xffff)
65 #define SSIP_MSG_ID(data) ((data) & 0xff)
66 /* Generic Command */
67 #define SSIP_CMD(cmd, payload) (((cmd) << 28) | ((payload) & 0xfffffff))
68 /* Commands for the control channel */
69 #define SSIP_BOOTINFO_REQ_CMD(ver) \
70 SSIP_CMD(SSIP_BOOTINFO_REQ, SSIP_DATA_VERSION(ver))
71 #define SSIP_BOOTINFO_RESP_CMD(ver) \
72 SSIP_CMD(SSIP_BOOTINFO_RESP, SSIP_DATA_VERSION(ver))
73 #define SSIP_START_TRANS_CMD(pdulen, id) \
74 SSIP_CMD(SSIP_START_TRANS, (((pdulen) << 8) | SSIP_MSG_ID(id)))
75 #define SSIP_READY_CMD SSIP_CMD(SSIP_READY, 0)
76 #define SSIP_SWBREAK_CMD SSIP_CMD(SSIP_SW_BREAK, 0)
77
78 #define SSIP_WAKETEST_FLAG 0
79
80 /* Main state machine states */
81 enum {
82 INIT,
83 HANDSHAKE,
84 ACTIVE,
85 };
86
87 /* Send state machine states */
88 enum {
89 SEND_IDLE,
90 WAIT4READY,
91 SEND_READY,
92 SENDING,
93 SENDING_SWBREAK,
94 };
95
96 /* Receive state machine states */
97 enum {
98 RECV_IDLE,
99 RECV_READY,
100 RECEIVING,
101 };
102
103 /**
104 * struct ssi_protocol - SSI protocol (McSAAB) data
105 * @main_state: Main state machine
106 * @send_state: TX state machine
107 * @recv_state: RX state machine
108 * @flags: Flags, currently only used to follow wake line test
109 * @rxid: RX data id
110 * @txid: TX data id
111 * @txqueue_len: TX queue length
112 * @tx_wd: TX watchdog
113 * @rx_wd: RX watchdog
114 * @keep_alive: Workaround for SSI HW bug
115 * @lock: To serialize access to this struct
116 * @netdev: Phonet network device
117 * @txqueue: TX data queue
118 * @cmdqueue: Queue of free commands
119 * @cl: HSI client own reference
120 * @link: Link for ssip_list
121 * @tx_usecount: Refcount to keep track the slaves that use the wake line
122 * @channel_id_cmd: HSI channel id for command stream
123 * @channel_id_data: HSI channel id for data stream
124 */
125 struct ssi_protocol {
126 unsigned int main_state;
127 unsigned int send_state;
128 unsigned int recv_state;
129 unsigned long flags;
130 u8 rxid;
131 u8 txid;
132 unsigned int txqueue_len;
133 struct timer_list tx_wd;
134 struct timer_list rx_wd;
135 struct timer_list keep_alive; /* wake-up workaround */
136 spinlock_t lock;
137 struct net_device *netdev;
138 struct list_head txqueue;
139 struct list_head cmdqueue;
140 struct work_struct work;
141 struct hsi_client *cl;
142 struct list_head link;
143 atomic_t tx_usecnt;
144 int channel_id_cmd;
145 int channel_id_data;
146 };
147
148 /* List of ssi protocol instances */
149 static LIST_HEAD(ssip_list);
150
151 static void ssip_rxcmd_complete(struct hsi_msg *msg);
152
153 static inline void ssip_set_cmd(struct hsi_msg *msg, u32 cmd)
154 {
155 u32 *data;
156
157 data = sg_virt(msg->sgt.sgl);
158 *data = cmd;
159 }
160
161 static inline u32 ssip_get_cmd(struct hsi_msg *msg)
162 {
163 u32 *data;
164
165 data = sg_virt(msg->sgt.sgl);
166
167 return *data;
168 }
169
170 static void ssip_skb_to_msg(struct sk_buff *skb, struct hsi_msg *msg)
171 {
172 skb_frag_t *frag;
173 struct scatterlist *sg;
174 int i;
175
176 BUG_ON(msg->sgt.nents != (unsigned int)(skb_shinfo(skb)->nr_frags + 1));
177
178 sg = msg->sgt.sgl;
179 sg_set_buf(sg, skb->data, skb_headlen(skb));
180 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
181 sg = sg_next(sg);
182 BUG_ON(!sg);
183 frag = &skb_shinfo(skb)->frags[i];
184 sg_set_page(sg, skb_frag_page(frag), skb_frag_size(frag),
185 skb_frag_off(frag));
186 }
187 }
188
189 static void ssip_free_data(struct hsi_msg *msg)
190 {
191 struct sk_buff *skb;
192
193 skb = msg->context;
194 pr_debug("free data: msg %p context %p skb %p\n", msg, msg->context,
195 skb);
196 msg->destructor = NULL;
197 dev_kfree_skb(skb);
198 hsi_free_msg(msg);
199 }
200
201 static struct hsi_msg *ssip_alloc_data(struct ssi_protocol *ssi,
202 struct sk_buff *skb, gfp_t flags)
203 {
204 struct hsi_msg *msg;
205
206 msg = hsi_alloc_msg(skb_shinfo(skb)->nr_frags + 1, flags);
207 if (!msg)
208 return NULL;
209 ssip_skb_to_msg(skb, msg);
210 msg->destructor = ssip_free_data;
211 msg->channel = ssi->channel_id_data;
212 msg->context = skb;
213
214 return msg;
215 }
216
217 static inline void ssip_release_cmd(struct hsi_msg *msg)
218 {
219 struct ssi_protocol *ssi = hsi_client_drvdata(msg->cl);
220
221 dev_dbg(&msg->cl->device, "Release cmd 0x%08x\n", ssip_get_cmd(msg));
222 spin_lock_bh(&ssi->lock);
223 list_add_tail(&msg->link, &ssi->cmdqueue);
224 spin_unlock_bh(&ssi->lock);
225 }
226
227 static struct hsi_msg *ssip_claim_cmd(struct ssi_protocol *ssi)
228 {
229 struct hsi_msg *msg;
230
231 BUG_ON(list_empty(&ssi->cmdqueue));
232
233 spin_lock_bh(&ssi->lock);
234 msg = list_first_entry(&ssi->cmdqueue, struct hsi_msg, link);
235 list_del(&msg->link);
236 spin_unlock_bh(&ssi->lock);
237 msg->destructor = ssip_release_cmd;
238
239 return msg;
240 }
241
242 static void ssip_free_cmds(struct ssi_protocol *ssi)
243 {
244 struct hsi_msg *msg, *tmp;
245
246 list_for_each_entry_safe(msg, tmp, &ssi->cmdqueue, link) {
247 list_del(&msg->link);
248 msg->destructor = NULL;
249 kfree(sg_virt(msg->sgt.sgl));
250 hsi_free_msg(msg);
251 }
252 }
253
254 static int ssip_alloc_cmds(struct ssi_protocol *ssi)
255 {
256 struct hsi_msg *msg;
257 u32 *buf;
258 unsigned int i;
259
260 for (i = 0; i < SSIP_MAX_CMDS; i++) {
261 msg = hsi_alloc_msg(1, GFP_KERNEL);
262 if (!msg)
263 goto out;
264 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
265 if (!buf) {
266 hsi_free_msg(msg);
267 goto out;
268 }
269 sg_init_one(msg->sgt.sgl, buf, sizeof(*buf));
270 msg->channel = ssi->channel_id_cmd;
271 list_add_tail(&msg->link, &ssi->cmdqueue);
272 }
273
274 return 0;
275 out:
276 ssip_free_cmds(ssi);
277
278 return -ENOMEM;
279 }
280
281 static void ssip_set_rxstate(struct ssi_protocol *ssi, unsigned int state)
282 {
283 ssi->recv_state = state;
284 switch (state) {
285 case RECV_IDLE:
286 del_timer(&ssi->rx_wd);
287 if (ssi->send_state == SEND_IDLE)
288 del_timer(&ssi->keep_alive);
289 break;
290 case RECV_READY:
291 /* CMT speech workaround */
292 if (atomic_read(&ssi->tx_usecnt))
293 break;
294 fallthrough;
295 case RECEIVING:
296 mod_timer(&ssi->keep_alive, jiffies +
297 msecs_to_jiffies(SSIP_KATOUT));
298 mod_timer(&ssi->rx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
299 break;
300 default:
301 break;
302 }
303 }
304
305 static void ssip_set_txstate(struct ssi_protocol *ssi, unsigned int state)
306 {
307 ssi->send_state = state;
308 switch (state) {
309 case SEND_IDLE:
310 case SEND_READY:
311 del_timer(&ssi->tx_wd);
312 if (ssi->recv_state == RECV_IDLE)
313 del_timer(&ssi->keep_alive);
314 break;
315 case WAIT4READY:
316 case SENDING:
317 case SENDING_SWBREAK:
318 mod_timer(&ssi->keep_alive,
319 jiffies + msecs_to_jiffies(SSIP_KATOUT));
320 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
321 break;
322 default:
323 break;
324 }
325 }
326
327 struct hsi_client *ssip_slave_get_master(struct hsi_client *slave)
328 {
329 struct hsi_client *master = ERR_PTR(-ENODEV);
330 struct ssi_protocol *ssi;
331
332 list_for_each_entry(ssi, &ssip_list, link)
333 if (slave->device.parent == ssi->cl->device.parent) {
334 master = ssi->cl;
335 break;
336 }
337
338 return master;
339 }
340 EXPORT_SYMBOL_GPL(ssip_slave_get_master);
341
342 int ssip_slave_start_tx(struct hsi_client *master)
343 {
344 struct ssi_protocol *ssi = hsi_client_drvdata(master);
345
346 dev_dbg(&master->device, "start TX %d\n", atomic_read(&ssi->tx_usecnt));
347 spin_lock_bh(&ssi->lock);
348 if (ssi->send_state == SEND_IDLE) {
349 ssip_set_txstate(ssi, WAIT4READY);
350 hsi_start_tx(master);
351 }
352 spin_unlock_bh(&ssi->lock);
353 atomic_inc(&ssi->tx_usecnt);
354
355 return 0;
356 }
357 EXPORT_SYMBOL_GPL(ssip_slave_start_tx);
358
359 int ssip_slave_stop_tx(struct hsi_client *master)
360 {
361 struct ssi_protocol *ssi = hsi_client_drvdata(master);
362
363 WARN_ON_ONCE(atomic_read(&ssi->tx_usecnt) == 0);
364
365 if (atomic_dec_and_test(&ssi->tx_usecnt)) {
366 spin_lock_bh(&ssi->lock);
367 if ((ssi->send_state == SEND_READY) ||
368 (ssi->send_state == WAIT4READY)) {
369 ssip_set_txstate(ssi, SEND_IDLE);
370 hsi_stop_tx(master);
371 }
372 spin_unlock_bh(&ssi->lock);
373 }
374 dev_dbg(&master->device, "stop TX %d\n", atomic_read(&ssi->tx_usecnt));
375
376 return 0;
377 }
378 EXPORT_SYMBOL_GPL(ssip_slave_stop_tx);
379
380 int ssip_slave_running(struct hsi_client *master)
381 {
382 struct ssi_protocol *ssi = hsi_client_drvdata(master);
383 return netif_running(ssi->netdev);
384 }
385 EXPORT_SYMBOL_GPL(ssip_slave_running);
386
387 static void ssip_reset(struct hsi_client *cl)
388 {
389 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
390 struct list_head *head, *tmp;
391 struct hsi_msg *msg;
392
393 if (netif_running(ssi->netdev))
394 netif_carrier_off(ssi->netdev);
395 hsi_flush(cl);
396 spin_lock_bh(&ssi->lock);
397 if (ssi->send_state != SEND_IDLE)
398 hsi_stop_tx(cl);
399 spin_unlock_bh(&ssi->lock);
400 if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
401 ssi_waketest(cl, 0); /* FIXME: To be removed */
402 spin_lock_bh(&ssi->lock);
403 del_timer(&ssi->rx_wd);
404 del_timer(&ssi->tx_wd);
405 del_timer(&ssi->keep_alive);
406 ssi->main_state = 0;
407 ssi->send_state = 0;
408 ssi->recv_state = 0;
409 ssi->flags = 0;
410 ssi->rxid = 0;
411 ssi->txid = 0;
412 list_for_each_safe(head, tmp, &ssi->txqueue) {
413 msg = list_entry(head, struct hsi_msg, link);
414 dev_dbg(&cl->device, "Pending TX data\n");
415 list_del(head);
416 ssip_free_data(msg);
417 }
418 ssi->txqueue_len = 0;
419 spin_unlock_bh(&ssi->lock);
420 }
421
422 static void ssip_dump_state(struct hsi_client *cl)
423 {
424 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
425 struct hsi_msg *msg;
426
427 spin_lock_bh(&ssi->lock);
428 dev_err(&cl->device, "Main state: %d\n", ssi->main_state);
429 dev_err(&cl->device, "Recv state: %d\n", ssi->recv_state);
430 dev_err(&cl->device, "Send state: %d\n", ssi->send_state);
431 dev_err(&cl->device, "CMT %s\n", (ssi->main_state == ACTIVE) ?
432 "Online" : "Offline");
433 dev_err(&cl->device, "Wake test %d\n",
434 test_bit(SSIP_WAKETEST_FLAG, &ssi->flags));
435 dev_err(&cl->device, "Data RX id: %d\n", ssi->rxid);
436 dev_err(&cl->device, "Data TX id: %d\n", ssi->txid);
437
438 list_for_each_entry(msg, &ssi->txqueue, link)
439 dev_err(&cl->device, "pending TX data (%p)\n", msg);
440 spin_unlock_bh(&ssi->lock);
441 }
442
443 static void ssip_error(struct hsi_client *cl)
444 {
445 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
446 struct hsi_msg *msg;
447
448 ssip_dump_state(cl);
449 ssip_reset(cl);
450 msg = ssip_claim_cmd(ssi);
451 msg->complete = ssip_rxcmd_complete;
452 hsi_async_read(cl, msg);
453 }
454
455 static void ssip_keep_alive(struct timer_list *t)
456 {
457 struct ssi_protocol *ssi = from_timer(ssi, t, keep_alive);
458 struct hsi_client *cl = ssi->cl;
459
460 dev_dbg(&cl->device, "Keep alive kick in: m(%d) r(%d) s(%d)\n",
461 ssi->main_state, ssi->recv_state, ssi->send_state);
462
463 spin_lock(&ssi->lock);
464 if (ssi->recv_state == RECV_IDLE)
465 switch (ssi->send_state) {
466 case SEND_READY:
467 if (atomic_read(&ssi->tx_usecnt) == 0)
468 break;
469 fallthrough;
470 /*
471 * Workaround for cmt-speech in that case
472 * we relay on audio timers.
473 */
474 case SEND_IDLE:
475 spin_unlock(&ssi->lock);
476 return;
477 }
478 mod_timer(&ssi->keep_alive, jiffies + msecs_to_jiffies(SSIP_KATOUT));
479 spin_unlock(&ssi->lock);
480 }
481
482 static void ssip_rx_wd(struct timer_list *t)
483 {
484 struct ssi_protocol *ssi = from_timer(ssi, t, rx_wd);
485 struct hsi_client *cl = ssi->cl;
486
487 dev_err(&cl->device, "Watchdog triggered\n");
488 ssip_error(cl);
489 }
490
491 static void ssip_tx_wd(struct timer_list *t)
492 {
493 struct ssi_protocol *ssi = from_timer(ssi, t, tx_wd);
494 struct hsi_client *cl = ssi->cl;
495
496 dev_err(&cl->device, "Watchdog triggered\n");
497 ssip_error(cl);
498 }
499
500 static void ssip_send_bootinfo_req_cmd(struct hsi_client *cl)
501 {
502 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
503 struct hsi_msg *msg;
504
505 dev_dbg(&cl->device, "Issuing BOOT INFO REQ command\n");
506 msg = ssip_claim_cmd(ssi);
507 ssip_set_cmd(msg, SSIP_BOOTINFO_REQ_CMD(SSIP_LOCAL_VERID));
508 msg->complete = ssip_release_cmd;
509 hsi_async_write(cl, msg);
510 dev_dbg(&cl->device, "Issuing RX command\n");
511 msg = ssip_claim_cmd(ssi);
512 msg->complete = ssip_rxcmd_complete;
513 hsi_async_read(cl, msg);
514 }
515
516 static void ssip_start_rx(struct hsi_client *cl)
517 {
518 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
519 struct hsi_msg *msg;
520
521 dev_dbg(&cl->device, "RX start M(%d) R(%d)\n", ssi->main_state,
522 ssi->recv_state);
523 spin_lock_bh(&ssi->lock);
524 /*
525 * We can have two UP events in a row due to a short low
526 * high transition. Therefore we need to ignore the sencond UP event.
527 */
528 if ((ssi->main_state != ACTIVE) || (ssi->recv_state == RECV_READY)) {
529 spin_unlock_bh(&ssi->lock);
530 return;
531 }
532 ssip_set_rxstate(ssi, RECV_READY);
533 spin_unlock_bh(&ssi->lock);
534
535 msg = ssip_claim_cmd(ssi);
536 ssip_set_cmd(msg, SSIP_READY_CMD);
537 msg->complete = ssip_release_cmd;
538 dev_dbg(&cl->device, "Send READY\n");
539 hsi_async_write(cl, msg);
540 }
541
542 static void ssip_stop_rx(struct hsi_client *cl)
543 {
544 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
545
546 dev_dbg(&cl->device, "RX stop M(%d)\n", ssi->main_state);
547 spin_lock_bh(&ssi->lock);
548 if (likely(ssi->main_state == ACTIVE))
549 ssip_set_rxstate(ssi, RECV_IDLE);
550 spin_unlock_bh(&ssi->lock);
551 }
552
553 static void ssip_free_strans(struct hsi_msg *msg)
554 {
555 ssip_free_data(msg->context);
556 ssip_release_cmd(msg);
557 }
558
559 static void ssip_strans_complete(struct hsi_msg *msg)
560 {
561 struct hsi_client *cl = msg->cl;
562 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
563 struct hsi_msg *data;
564
565 data = msg->context;
566 ssip_release_cmd(msg);
567 spin_lock_bh(&ssi->lock);
568 ssip_set_txstate(ssi, SENDING);
569 spin_unlock_bh(&ssi->lock);
570 hsi_async_write(cl, data);
571 }
572
573 static int ssip_xmit(struct hsi_client *cl)
574 {
575 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
576 struct hsi_msg *msg, *dmsg;
577 struct sk_buff *skb;
578
579 spin_lock_bh(&ssi->lock);
580 if (list_empty(&ssi->txqueue)) {
581 spin_unlock_bh(&ssi->lock);
582 return 0;
583 }
584 dmsg = list_first_entry(&ssi->txqueue, struct hsi_msg, link);
585 list_del(&dmsg->link);
586 ssi->txqueue_len--;
587 spin_unlock_bh(&ssi->lock);
588
589 msg = ssip_claim_cmd(ssi);
590 skb = dmsg->context;
591 msg->context = dmsg;
592 msg->complete = ssip_strans_complete;
593 msg->destructor = ssip_free_strans;
594
595 spin_lock_bh(&ssi->lock);
596 ssip_set_cmd(msg, SSIP_START_TRANS_CMD(SSIP_BYTES_TO_FRAMES(skb->len),
597 ssi->txid));
598 ssi->txid++;
599 ssip_set_txstate(ssi, SENDING);
600 spin_unlock_bh(&ssi->lock);
601
602 dev_dbg(&cl->device, "Send STRANS (%d frames)\n",
603 SSIP_BYTES_TO_FRAMES(skb->len));
604
605 return hsi_async_write(cl, msg);
606 }
607
608 /* In soft IRQ context */
609 static void ssip_pn_rx(struct sk_buff *skb)
610 {
611 struct net_device *dev = skb->dev;
612
613 if (unlikely(!netif_running(dev))) {
614 dev_dbg(&dev->dev, "Drop RX packet\n");
615 dev->stats.rx_dropped++;
616 dev_kfree_skb(skb);
617 return;
618 }
619 if (unlikely(!pskb_may_pull(skb, SSIP_MIN_PN_HDR))) {
620 dev_dbg(&dev->dev, "Error drop RX packet\n");
621 dev->stats.rx_errors++;
622 dev->stats.rx_length_errors++;
623 dev_kfree_skb(skb);
624 return;
625 }
626 dev->stats.rx_packets++;
627 dev->stats.rx_bytes += skb->len;
628
629 /* length field is exchanged in network byte order */
630 ((u16 *)skb->data)[2] = ntohs(((u16 *)skb->data)[2]);
631 dev_dbg(&dev->dev, "RX length fixed (%04x -> %u)\n",
632 ((u16 *)skb->data)[2], ntohs(((u16 *)skb->data)[2]));
633
634 skb->protocol = htons(ETH_P_PHONET);
635 skb_reset_mac_header(skb);
636 __skb_pull(skb, 1);
637 netif_rx(skb);
638 }
639
640 static void ssip_rx_data_complete(struct hsi_msg *msg)
641 {
642 struct hsi_client *cl = msg->cl;
643 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
644 struct sk_buff *skb;
645
646 if (msg->status == HSI_STATUS_ERROR) {
647 dev_err(&cl->device, "RX data error\n");
648 ssip_free_data(msg);
649 ssip_error(cl);
650 return;
651 }
652 del_timer(&ssi->rx_wd); /* FIXME: Revisit */
653 skb = msg->context;
654 ssip_pn_rx(skb);
655 hsi_free_msg(msg);
656 }
657
658 static void ssip_rx_bootinforeq(struct hsi_client *cl, u32 cmd)
659 {
660 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
661 struct hsi_msg *msg;
662
663 /* Workaroud: Ignore CMT Loader message leftover */
664 if (cmd == SSIP_CMT_LOADER_SYNC)
665 return;
666
667 switch (ssi->main_state) {
668 case ACTIVE:
669 dev_err(&cl->device, "Boot info req on active state\n");
670 ssip_error(cl);
671 fallthrough;
672 case INIT:
673 case HANDSHAKE:
674 spin_lock_bh(&ssi->lock);
675 ssi->main_state = HANDSHAKE;
676 spin_unlock_bh(&ssi->lock);
677
678 if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
679 ssi_waketest(cl, 1); /* FIXME: To be removed */
680
681 spin_lock_bh(&ssi->lock);
682 /* Start boot handshake watchdog */
683 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
684 spin_unlock_bh(&ssi->lock);
685 dev_dbg(&cl->device, "Send BOOTINFO_RESP\n");
686 if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
687 dev_warn(&cl->device, "boot info req verid mismatch\n");
688 msg = ssip_claim_cmd(ssi);
689 ssip_set_cmd(msg, SSIP_BOOTINFO_RESP_CMD(SSIP_LOCAL_VERID));
690 msg->complete = ssip_release_cmd;
691 hsi_async_write(cl, msg);
692 break;
693 default:
694 dev_dbg(&cl->device, "Wrong state M(%d)\n", ssi->main_state);
695 break;
696 }
697 }
698
699 static void ssip_rx_bootinforesp(struct hsi_client *cl, u32 cmd)
700 {
701 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
702
703 if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
704 dev_warn(&cl->device, "boot info resp verid mismatch\n");
705
706 spin_lock_bh(&ssi->lock);
707 if (ssi->main_state != ACTIVE)
708 /* Use tx_wd as a boot watchdog in non ACTIVE state */
709 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
710 else
711 dev_dbg(&cl->device, "boot info resp ignored M(%d)\n",
712 ssi->main_state);
713 spin_unlock_bh(&ssi->lock);
714 }
715
716 static void ssip_rx_waketest(struct hsi_client *cl, u32 cmd)
717 {
718 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
719 unsigned int wkres = SSIP_PAYLOAD(cmd);
720
721 spin_lock_bh(&ssi->lock);
722 if (ssi->main_state != HANDSHAKE) {
723 dev_dbg(&cl->device, "wake lines test ignored M(%d)\n",
724 ssi->main_state);
725 spin_unlock_bh(&ssi->lock);
726 return;
727 }
728 spin_unlock_bh(&ssi->lock);
729
730 if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
731 ssi_waketest(cl, 0); /* FIXME: To be removed */
732
733 spin_lock_bh(&ssi->lock);
734 ssi->main_state = ACTIVE;
735 del_timer(&ssi->tx_wd); /* Stop boot handshake timer */
736 spin_unlock_bh(&ssi->lock);
737
738 dev_notice(&cl->device, "WAKELINES TEST %s\n",
739 wkres & SSIP_WAKETEST_FAILED ? "FAILED" : "OK");
740 if (wkres & SSIP_WAKETEST_FAILED) {
741 ssip_error(cl);
742 return;
743 }
744 dev_dbg(&cl->device, "CMT is ONLINE\n");
745 netif_wake_queue(ssi->netdev);
746 netif_carrier_on(ssi->netdev);
747 }
748
749 static void ssip_rx_ready(struct hsi_client *cl)
750 {
751 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
752
753 spin_lock_bh(&ssi->lock);
754 if (unlikely(ssi->main_state != ACTIVE)) {
755 dev_dbg(&cl->device, "READY on wrong state: S(%d) M(%d)\n",
756 ssi->send_state, ssi->main_state);
757 spin_unlock_bh(&ssi->lock);
758 return;
759 }
760 if (ssi->send_state != WAIT4READY) {
761 dev_dbg(&cl->device, "Ignore spurious READY command\n");
762 spin_unlock_bh(&ssi->lock);
763 return;
764 }
765 ssip_set_txstate(ssi, SEND_READY);
766 spin_unlock_bh(&ssi->lock);
767 ssip_xmit(cl);
768 }
769
770 static void ssip_rx_strans(struct hsi_client *cl, u32 cmd)
771 {
772 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
773 struct sk_buff *skb;
774 struct hsi_msg *msg;
775 int len = SSIP_PDU_LENGTH(cmd);
776
777 dev_dbg(&cl->device, "RX strans: %d frames\n", len);
778 spin_lock_bh(&ssi->lock);
779 if (unlikely(ssi->main_state != ACTIVE)) {
780 dev_err(&cl->device, "START TRANS wrong state: S(%d) M(%d)\n",
781 ssi->send_state, ssi->main_state);
782 spin_unlock_bh(&ssi->lock);
783 return;
784 }
785 ssip_set_rxstate(ssi, RECEIVING);
786 if (unlikely(SSIP_MSG_ID(cmd) != ssi->rxid)) {
787 dev_err(&cl->device, "START TRANS id %d expected %d\n",
788 SSIP_MSG_ID(cmd), ssi->rxid);
789 spin_unlock_bh(&ssi->lock);
790 goto out1;
791 }
792 ssi->rxid++;
793 spin_unlock_bh(&ssi->lock);
794 skb = netdev_alloc_skb(ssi->netdev, len * 4);
795 if (unlikely(!skb)) {
796 dev_err(&cl->device, "No memory for rx skb\n");
797 goto out1;
798 }
799 skb->dev = ssi->netdev;
800 skb_put(skb, len * 4);
801 msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
802 if (unlikely(!msg)) {
803 dev_err(&cl->device, "No memory for RX data msg\n");
804 goto out2;
805 }
806 msg->complete = ssip_rx_data_complete;
807 hsi_async_read(cl, msg);
808
809 return;
810 out2:
811 dev_kfree_skb(skb);
812 out1:
813 ssip_error(cl);
814 }
815
816 static void ssip_rxcmd_complete(struct hsi_msg *msg)
817 {
818 struct hsi_client *cl = msg->cl;
819 u32 cmd = ssip_get_cmd(msg);
820 unsigned int cmdid = SSIP_COMMAND(cmd);
821
822 if (msg->status == HSI_STATUS_ERROR) {
823 dev_err(&cl->device, "RX error detected\n");
824 ssip_release_cmd(msg);
825 ssip_error(cl);
826 return;
827 }
828 hsi_async_read(cl, msg);
829 dev_dbg(&cl->device, "RX cmd: 0x%08x\n", cmd);
830 switch (cmdid) {
831 case SSIP_SW_BREAK:
832 /* Ignored */
833 break;
834 case SSIP_BOOTINFO_REQ:
835 ssip_rx_bootinforeq(cl, cmd);
836 break;
837 case SSIP_BOOTINFO_RESP:
838 ssip_rx_bootinforesp(cl, cmd);
839 break;
840 case SSIP_WAKETEST_RESULT:
841 ssip_rx_waketest(cl, cmd);
842 break;
843 case SSIP_START_TRANS:
844 ssip_rx_strans(cl, cmd);
845 break;
846 case SSIP_READY:
847 ssip_rx_ready(cl);
848 break;
849 default:
850 dev_warn(&cl->device, "command 0x%08x not supported\n", cmd);
851 break;
852 }
853 }
854
855 static void ssip_swbreak_complete(struct hsi_msg *msg)
856 {
857 struct hsi_client *cl = msg->cl;
858 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
859
860 ssip_release_cmd(msg);
861 spin_lock_bh(&ssi->lock);
862 if (list_empty(&ssi->txqueue)) {
863 if (atomic_read(&ssi->tx_usecnt)) {
864 ssip_set_txstate(ssi, SEND_READY);
865 } else {
866 ssip_set_txstate(ssi, SEND_IDLE);
867 hsi_stop_tx(cl);
868 }
869 spin_unlock_bh(&ssi->lock);
870 } else {
871 spin_unlock_bh(&ssi->lock);
872 ssip_xmit(cl);
873 }
874 netif_wake_queue(ssi->netdev);
875 }
876
877 static void ssip_tx_data_complete(struct hsi_msg *msg)
878 {
879 struct hsi_client *cl = msg->cl;
880 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
881 struct hsi_msg *cmsg;
882
883 if (msg->status == HSI_STATUS_ERROR) {
884 dev_err(&cl->device, "TX data error\n");
885 ssip_error(cl);
886 goto out;
887 }
888 spin_lock_bh(&ssi->lock);
889 if (list_empty(&ssi->txqueue)) {
890 ssip_set_txstate(ssi, SENDING_SWBREAK);
891 spin_unlock_bh(&ssi->lock);
892 cmsg = ssip_claim_cmd(ssi);
893 ssip_set_cmd(cmsg, SSIP_SWBREAK_CMD);
894 cmsg->complete = ssip_swbreak_complete;
895 dev_dbg(&cl->device, "Send SWBREAK\n");
896 hsi_async_write(cl, cmsg);
897 } else {
898 spin_unlock_bh(&ssi->lock);
899 ssip_xmit(cl);
900 }
901 out:
902 ssip_free_data(msg);
903 }
904
905 static void ssip_port_event(struct hsi_client *cl, unsigned long event)
906 {
907 switch (event) {
908 case HSI_EVENT_START_RX:
909 ssip_start_rx(cl);
910 break;
911 case HSI_EVENT_STOP_RX:
912 ssip_stop_rx(cl);
913 break;
914 default:
915 return;
916 }
917 }
918
919 static int ssip_pn_open(struct net_device *dev)
920 {
921 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
922 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
923 int err;
924
925 err = hsi_claim_port(cl, 1);
926 if (err < 0) {
927 dev_err(&cl->device, "SSI port already claimed\n");
928 return err;
929 }
930 err = hsi_register_port_event(cl, ssip_port_event);
931 if (err < 0) {
932 dev_err(&cl->device, "Register HSI port event failed (%d)\n",
933 err);
934 return err;
935 }
936 dev_dbg(&cl->device, "Configuring SSI port\n");
937 hsi_setup(cl);
938
939 if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
940 ssi_waketest(cl, 1); /* FIXME: To be removed */
941
942 spin_lock_bh(&ssi->lock);
943 ssi->main_state = HANDSHAKE;
944 spin_unlock_bh(&ssi->lock);
945
946 ssip_send_bootinfo_req_cmd(cl);
947
948 return 0;
949 }
950
951 static int ssip_pn_stop(struct net_device *dev)
952 {
953 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
954
955 ssip_reset(cl);
956 hsi_unregister_port_event(cl);
957 hsi_release_port(cl);
958
959 return 0;
960 }
961
962 static void ssip_xmit_work(struct work_struct *work)
963 {
964 struct ssi_protocol *ssi =
965 container_of(work, struct ssi_protocol, work);
966 struct hsi_client *cl = ssi->cl;
967
968 ssip_xmit(cl);
969 }
970
971 static int ssip_pn_xmit(struct sk_buff *skb, struct net_device *dev)
972 {
973 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
974 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
975 struct hsi_msg *msg;
976
977 if ((skb->protocol != htons(ETH_P_PHONET)) ||
978 (skb->len < SSIP_MIN_PN_HDR))
979 goto drop;
980 /* Pad to 32-bits - FIXME: Revisit*/
981 if ((skb->len & 3) && skb_pad(skb, 4 - (skb->len & 3)))
982 goto inc_dropped;
983
984 /*
985 * Modem sends Phonet messages over SSI with its own endianness.
986 * Assume that modem has the same endianness as we do.
987 */
988 if (skb_cow_head(skb, 0))
989 goto drop;
990
991 /* length field is exchanged in network byte order */
992 ((u16 *)skb->data)[2] = htons(((u16 *)skb->data)[2]);
993
994 msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
995 if (!msg) {
996 dev_dbg(&cl->device, "Dropping tx data: No memory\n");
997 goto drop;
998 }
999 msg->complete = ssip_tx_data_complete;
1000
1001 spin_lock_bh(&ssi->lock);
1002 if (unlikely(ssi->main_state != ACTIVE)) {
1003 spin_unlock_bh(&ssi->lock);
1004 dev_dbg(&cl->device, "Dropping tx data: CMT is OFFLINE\n");
1005 goto drop2;
1006 }
1007 list_add_tail(&msg->link, &ssi->txqueue);
1008 ssi->txqueue_len++;
1009 if (dev->tx_queue_len < ssi->txqueue_len) {
1010 dev_info(&cl->device, "TX queue full %d\n", ssi->txqueue_len);
1011 netif_stop_queue(dev);
1012 }
1013 if (ssi->send_state == SEND_IDLE) {
1014 ssip_set_txstate(ssi, WAIT4READY);
1015 spin_unlock_bh(&ssi->lock);
1016 dev_dbg(&cl->device, "Start TX qlen %d\n", ssi->txqueue_len);
1017 hsi_start_tx(cl);
1018 } else if (ssi->send_state == SEND_READY) {
1019 /* Needed for cmt-speech workaround */
1020 dev_dbg(&cl->device, "Start TX on SEND READY qlen %d\n",
1021 ssi->txqueue_len);
1022 spin_unlock_bh(&ssi->lock);
1023 schedule_work(&ssi->work);
1024 } else {
1025 spin_unlock_bh(&ssi->lock);
1026 }
1027 dev->stats.tx_packets++;
1028 dev->stats.tx_bytes += skb->len;
1029
1030 return 0;
1031 drop2:
1032 hsi_free_msg(msg);
1033 drop:
1034 dev_kfree_skb(skb);
1035 inc_dropped:
1036 dev->stats.tx_dropped++;
1037
1038 return 0;
1039 }
1040
1041 /* CMT reset event handler */
1042 void ssip_reset_event(struct hsi_client *master)
1043 {
1044 struct ssi_protocol *ssi = hsi_client_drvdata(master);
1045 dev_err(&ssi->cl->device, "CMT reset detected!\n");
1046 ssip_error(ssi->cl);
1047 }
1048 EXPORT_SYMBOL_GPL(ssip_reset_event);
1049
1050 static const struct net_device_ops ssip_pn_ops = {
1051 .ndo_open = ssip_pn_open,
1052 .ndo_stop = ssip_pn_stop,
1053 .ndo_start_xmit = ssip_pn_xmit,
1054 };
1055
1056 static void ssip_pn_setup(struct net_device *dev)
1057 {
1058 dev->features = 0;
1059 dev->netdev_ops = &ssip_pn_ops;
1060 dev->type = ARPHRD_PHONET;
1061 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1062 dev->mtu = SSIP_DEFAULT_MTU;
1063 dev->hard_header_len = 1;
1064 dev->dev_addr[0] = PN_MEDIA_SOS;
1065 dev->addr_len = 1;
1066 dev->tx_queue_len = SSIP_TXQUEUE_LEN;
1067
1068 dev->needs_free_netdev = true;
1069 dev->header_ops = &phonet_header_ops;
1070 }
1071
1072 static int ssi_protocol_probe(struct device *dev)
1073 {
1074 static const char ifname[] = "phonet%d";
1075 struct hsi_client *cl = to_hsi_client(dev);
1076 struct ssi_protocol *ssi;
1077 int err;
1078
1079 ssi = kzalloc(sizeof(*ssi), GFP_KERNEL);
1080 if (!ssi)
1081 return -ENOMEM;
1082
1083 spin_lock_init(&ssi->lock);
1084 timer_setup(&ssi->rx_wd, ssip_rx_wd, TIMER_DEFERRABLE);
1085 timer_setup(&ssi->tx_wd, ssip_tx_wd, TIMER_DEFERRABLE);
1086 timer_setup(&ssi->keep_alive, ssip_keep_alive, 0);
1087 INIT_LIST_HEAD(&ssi->txqueue);
1088 INIT_LIST_HEAD(&ssi->cmdqueue);
1089 atomic_set(&ssi->tx_usecnt, 0);
1090 hsi_client_set_drvdata(cl, ssi);
1091 ssi->cl = cl;
1092 INIT_WORK(&ssi->work, ssip_xmit_work);
1093
1094 ssi->channel_id_cmd = hsi_get_channel_id_by_name(cl, "mcsaab-control");
1095 if (ssi->channel_id_cmd < 0) {
1096 err = ssi->channel_id_cmd;
1097 dev_err(dev, "Could not get cmd channel (%d)\n", err);
1098 goto out;
1099 }
1100
1101 ssi->channel_id_data = hsi_get_channel_id_by_name(cl, "mcsaab-data");
1102 if (ssi->channel_id_data < 0) {
1103 err = ssi->channel_id_data;
1104 dev_err(dev, "Could not get data channel (%d)\n", err);
1105 goto out;
1106 }
1107
1108 err = ssip_alloc_cmds(ssi);
1109 if (err < 0) {
1110 dev_err(dev, "No memory for commands\n");
1111 goto out;
1112 }
1113
1114 ssi->netdev = alloc_netdev(0, ifname, NET_NAME_UNKNOWN, ssip_pn_setup);
1115 if (!ssi->netdev) {
1116 dev_err(dev, "No memory for netdev\n");
1117 err = -ENOMEM;
1118 goto out1;
1119 }
1120
1121 /* MTU range: 6 - 65535 */
1122 ssi->netdev->min_mtu = PHONET_MIN_MTU;
1123 ssi->netdev->max_mtu = SSIP_MAX_MTU;
1124
1125 SET_NETDEV_DEV(ssi->netdev, dev);
1126 netif_carrier_off(ssi->netdev);
1127 err = register_netdev(ssi->netdev);
1128 if (err < 0) {
1129 dev_err(dev, "Register netdev failed (%d)\n", err);
1130 goto out2;
1131 }
1132
1133 list_add(&ssi->link, &ssip_list);
1134
1135 dev_dbg(dev, "channel configuration: cmd=%d, data=%d\n",
1136 ssi->channel_id_cmd, ssi->channel_id_data);
1137
1138 return 0;
1139 out2:
1140 free_netdev(ssi->netdev);
1141 out1:
1142 ssip_free_cmds(ssi);
1143 out:
1144 kfree(ssi);
1145
1146 return err;
1147 }
1148
1149 static int ssi_protocol_remove(struct device *dev)
1150 {
1151 struct hsi_client *cl = to_hsi_client(dev);
1152 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
1153
1154 list_del(&ssi->link);
1155 unregister_netdev(ssi->netdev);
1156 ssip_free_cmds(ssi);
1157 hsi_client_set_drvdata(cl, NULL);
1158 kfree(ssi);
1159
1160 return 0;
1161 }
1162
1163 static struct hsi_client_driver ssip_driver = {
1164 .driver = {
1165 .name = "ssi-protocol",
1166 .owner = THIS_MODULE,
1167 .probe = ssi_protocol_probe,
1168 .remove = ssi_protocol_remove,
1169 },
1170 };
1171
1172 static int __init ssip_init(void)
1173 {
1174 pr_info("SSI protocol aka McSAAB added\n");
1175
1176 return hsi_register_client_driver(&ssip_driver);
1177 }
1178 module_init(ssip_init);
1179
1180 static void __exit ssip_exit(void)
1181 {
1182 hsi_unregister_client_driver(&ssip_driver);
1183 pr_info("SSI protocol driver removed\n");
1184 }
1185 module_exit(ssip_exit);
1186
1187 MODULE_ALIAS("hsi:ssi-protocol");
1188 MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
1189 MODULE_AUTHOR("Remi Denis-Courmont <remi.denis-courmont@nokia.com>");
1190 MODULE_DESCRIPTION("SSI protocol improved aka McSAAB");
1191 MODULE_LICENSE("GPL");
Linux with added FPC-III support