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/if_ether.h>
18 #include <linux/if_arp.h>
19 #include <linux/if_phonet.h>
20 #include <linux/init.h>
21 #include <linux/irq.h>
22 #include <linux/list.h>
23 #include <linux/module.h>
24 #include <linux/netdevice.h>
25 #include <linux/notifier.h>
26 #include <linux/scatterlist.h>
27 #include <linux/skbuff.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <linux/timer.h>
31 #include <linux/hsi/hsi.h>
32 #include <linux/hsi/ssi_protocol.h>
33
34 #define SSIP_TXQUEUE_LEN 100
35 #define SSIP_MAX_MTU 65535
36 #define SSIP_DEFAULT_MTU 4000
37 #define PN_MEDIA_SOS 21
38 #define SSIP_MIN_PN_HDR 6 /* FIXME: Revisit */
39 #define SSIP_WDTOUT 2000 /* FIXME: has to be 500 msecs */
40 #define SSIP_KATOUT 15 /* 15 msecs */
41 #define SSIP_MAX_CMDS 5 /* Number of pre-allocated commands buffers */
42 #define SSIP_BYTES_TO_FRAMES(x) ((((x) - 1) >> 2) + 1)
43 #define SSIP_CMT_LOADER_SYNC 0x11223344
44 /*
45 * SSI protocol command definitions
46 */
47 #define SSIP_COMMAND(data) ((data) >> 28)
48 #define SSIP_PAYLOAD(data) ((data) & 0xfffffff)
49 /* Commands */
50 #define SSIP_SW_BREAK 0
51 #define SSIP_BOOTINFO_REQ 1
52 #define SSIP_BOOTINFO_RESP 2
53 #define SSIP_WAKETEST_RESULT 3
54 #define SSIP_START_TRANS 4
55 #define SSIP_READY 5
56 /* Payloads */
57 #define SSIP_DATA_VERSION(data) ((data) & 0xff)
58 #define SSIP_LOCAL_VERID 1
59 #define SSIP_WAKETEST_OK 0
60 #define SSIP_WAKETEST_FAILED 1
61 #define SSIP_PDU_LENGTH(data) (((data) >> 8) & 0xffff)
62 #define SSIP_MSG_ID(data) ((data) & 0xff)
63 /* Generic Command */
64 #define SSIP_CMD(cmd, payload) (((cmd) << 28) | ((payload) & 0xfffffff))
65 /* Commands for the control channel */
66 #define SSIP_BOOTINFO_REQ_CMD(ver) \
67 SSIP_CMD(SSIP_BOOTINFO_REQ, SSIP_DATA_VERSION(ver))
68 #define SSIP_BOOTINFO_RESP_CMD(ver) \
69 SSIP_CMD(SSIP_BOOTINFO_RESP, SSIP_DATA_VERSION(ver))
70 #define SSIP_START_TRANS_CMD(pdulen, id) \
71 SSIP_CMD(SSIP_START_TRANS, (((pdulen) << 8) | SSIP_MSG_ID(id)))
72 #define SSIP_READY_CMD SSIP_CMD(SSIP_READY, 0)
73 #define SSIP_SWBREAK_CMD SSIP_CMD(SSIP_SW_BREAK, 0)
74
75 #define SSIP_WAKETEST_FLAG 0
76
77 /* Main state machine states */
78 enum {
79 INIT,
80 HANDSHAKE,
81 ACTIVE,
82 };
83
84 /* Send state machine states */
85 enum {
86 SEND_IDLE,
87 WAIT4READY,
88 SEND_READY,
89 SENDING,
90 SENDING_SWBREAK,
91 };
92
93 /* Receive state machine states */
94 enum {
95 RECV_IDLE,
96 RECV_READY,
97 RECEIVING,
98 };
99
100 /**
101 * struct ssi_protocol - SSI protocol (McSAAB) data
102 * @main_state: Main state machine
103 * @send_state: TX state machine
104 * @recv_state: RX state machine
105 * @flags: Flags, currently only used to follow wake line test
106 * @rxid: RX data id
107 * @txid: TX data id
108 * @txqueue_len: TX queue length
109 * @tx_wd: TX watchdog
110 * @rx_wd: RX watchdog
111 * @keep_alive: Workaround for SSI HW bug
112 * @lock: To serialize access to this struct
113 * @netdev: Phonet network device
114 * @txqueue: TX data queue
115 * @cmdqueue: Queue of free commands
116 * @work: &struct work_struct for scheduled work
117 * @cl: HSI client own reference
118 * @link: Link for ssip_list
119 * @tx_usecnt: Refcount to keep track the slaves that use the wake line
120 * @channel_id_cmd: HSI channel id for command stream
121 * @channel_id_data: HSI channel id for data stream
122 */
123 struct ssi_protocol {
124 unsigned int main_state;
125 unsigned int send_state;
126 unsigned int recv_state;
127 unsigned long flags;
128 u8 rxid;
129 u8 txid;
130 unsigned int txqueue_len;
131 struct timer_list tx_wd;
132 struct timer_list rx_wd;
133 struct timer_list keep_alive; /* wake-up workaround */
134 spinlock_t lock;
135 struct net_device *netdev;
136 struct list_head txqueue;
137 struct list_head cmdqueue;
138 struct work_struct work;
139 struct hsi_client *cl;
140 struct list_head link;
141 atomic_t tx_usecnt;
142 int channel_id_cmd;
143 int channel_id_data;
144 };
145
146 /* List of ssi protocol instances */
147 static LIST_HEAD(ssip_list);
148
149 static void ssip_rxcmd_complete(struct hsi_msg *msg);
150
ssip_set_cmd(struct hsi_msg * msg,u32 cmd)151 static inline void ssip_set_cmd(struct hsi_msg *msg, u32 cmd)
152 {
153 u32 *data;
154
155 data = sg_virt(msg->sgt.sgl);
156 *data = cmd;
157 }
158
ssip_get_cmd(struct hsi_msg * msg)159 static inline u32 ssip_get_cmd(struct hsi_msg *msg)
160 {
161 u32 *data;
162
163 data = sg_virt(msg->sgt.sgl);
164
165 return *data;
166 }
167
ssip_skb_to_msg(struct sk_buff * skb,struct hsi_msg * msg)168 static void ssip_skb_to_msg(struct sk_buff *skb, struct hsi_msg *msg)
169 {
170 skb_frag_t *frag;
171 struct scatterlist *sg;
172 int i;
173
174 BUG_ON(msg->sgt.nents != (unsigned int)(skb_shinfo(skb)->nr_frags + 1));
175
176 sg = msg->sgt.sgl;
177 sg_set_buf(sg, skb->data, skb_headlen(skb));
178 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
179 sg = sg_next(sg);
180 BUG_ON(!sg);
181 frag = &skb_shinfo(skb)->frags[i];
182 sg_set_page(sg, skb_frag_page(frag), skb_frag_size(frag),
183 skb_frag_off(frag));
184 }
185 }
186
ssip_free_data(struct hsi_msg * msg)187 static void ssip_free_data(struct hsi_msg *msg)
188 {
189 struct sk_buff *skb;
190
191 skb = msg->context;
192 pr_debug("free data: msg %p context %p skb %p\n", msg, msg->context,
193 skb);
194 msg->destructor = NULL;
195 dev_kfree_skb(skb);
196 hsi_free_msg(msg);
197 }
198
ssip_alloc_data(struct ssi_protocol * ssi,struct sk_buff * skb,gfp_t flags)199 static struct hsi_msg *ssip_alloc_data(struct ssi_protocol *ssi,
200 struct sk_buff *skb, gfp_t flags)
201 {
202 struct hsi_msg *msg;
203
204 msg = hsi_alloc_msg(skb_shinfo(skb)->nr_frags + 1, flags);
205 if (!msg)
206 return NULL;
207 ssip_skb_to_msg(skb, msg);
208 msg->destructor = ssip_free_data;
209 msg->channel = ssi->channel_id_data;
210 msg->context = skb;
211
212 return msg;
213 }
214
ssip_release_cmd(struct hsi_msg * msg)215 static inline void ssip_release_cmd(struct hsi_msg *msg)
216 {
217 struct ssi_protocol *ssi = hsi_client_drvdata(msg->cl);
218
219 dev_dbg(&msg->cl->device, "Release cmd 0x%08x\n", ssip_get_cmd(msg));
220 spin_lock_bh(&ssi->lock);
221 list_add_tail(&msg->link, &ssi->cmdqueue);
222 spin_unlock_bh(&ssi->lock);
223 }
224
ssip_claim_cmd(struct ssi_protocol * ssi)225 static struct hsi_msg *ssip_claim_cmd(struct ssi_protocol *ssi)
226 {
227 struct hsi_msg *msg;
228
229 BUG_ON(list_empty(&ssi->cmdqueue));
230
231 spin_lock_bh(&ssi->lock);
232 msg = list_first_entry(&ssi->cmdqueue, struct hsi_msg, link);
233 list_del(&msg->link);
234 spin_unlock_bh(&ssi->lock);
235 msg->destructor = ssip_release_cmd;
236
237 return msg;
238 }
239
ssip_free_cmds(struct ssi_protocol * ssi)240 static void ssip_free_cmds(struct ssi_protocol *ssi)
241 {
242 struct hsi_msg *msg, *tmp;
243
244 list_for_each_entry_safe(msg, tmp, &ssi->cmdqueue, link) {
245 list_del(&msg->link);
246 msg->destructor = NULL;
247 kfree(sg_virt(msg->sgt.sgl));
248 hsi_free_msg(msg);
249 }
250 }
251
ssip_alloc_cmds(struct ssi_protocol * ssi)252 static int ssip_alloc_cmds(struct ssi_protocol *ssi)
253 {
254 struct hsi_msg *msg;
255 u32 *buf;
256 unsigned int i;
257
258 for (i = 0; i < SSIP_MAX_CMDS; i++) {
259 msg = hsi_alloc_msg(1, GFP_KERNEL);
260 if (!msg)
261 goto out;
262 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
263 if (!buf) {
264 hsi_free_msg(msg);
265 goto out;
266 }
267 sg_init_one(msg->sgt.sgl, buf, sizeof(*buf));
268 msg->channel = ssi->channel_id_cmd;
269 list_add_tail(&msg->link, &ssi->cmdqueue);
270 }
271
272 return 0;
273 out:
274 ssip_free_cmds(ssi);
275
276 return -ENOMEM;
277 }
278
ssip_set_rxstate(struct ssi_protocol * ssi,unsigned int state)279 static void ssip_set_rxstate(struct ssi_protocol *ssi, unsigned int state)
280 {
281 ssi->recv_state = state;
282 switch (state) {
283 case RECV_IDLE:
284 timer_delete(&ssi->rx_wd);
285 if (ssi->send_state == SEND_IDLE)
286 timer_delete(&ssi->keep_alive);
287 break;
288 case RECV_READY:
289 /* CMT speech workaround */
290 if (atomic_read(&ssi->tx_usecnt))
291 break;
292 fallthrough;
293 case RECEIVING:
294 mod_timer(&ssi->keep_alive, jiffies +
295 msecs_to_jiffies(SSIP_KATOUT));
296 mod_timer(&ssi->rx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
297 break;
298 default:
299 break;
300 }
301 }
302
ssip_set_txstate(struct ssi_protocol * ssi,unsigned int state)303 static void ssip_set_txstate(struct ssi_protocol *ssi, unsigned int state)
304 {
305 ssi->send_state = state;
306 switch (state) {
307 case SEND_IDLE:
308 case SEND_READY:
309 timer_delete(&ssi->tx_wd);
310 if (ssi->recv_state == RECV_IDLE)
311 timer_delete(&ssi->keep_alive);
312 break;
313 case WAIT4READY:
314 case SENDING:
315 case SENDING_SWBREAK:
316 mod_timer(&ssi->keep_alive,
317 jiffies + msecs_to_jiffies(SSIP_KATOUT));
318 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
319 break;
320 default:
321 break;
322 }
323 }
324
ssip_slave_get_master(struct hsi_client * slave)325 struct hsi_client *ssip_slave_get_master(struct hsi_client *slave)
326 {
327 struct hsi_client *master = ERR_PTR(-ENODEV);
328 struct ssi_protocol *ssi;
329
330 list_for_each_entry(ssi, &ssip_list, link)
331 if (slave->device.parent == ssi->cl->device.parent) {
332 master = ssi->cl;
333 break;
334 }
335
336 return master;
337 }
338 EXPORT_SYMBOL_GPL(ssip_slave_get_master);
339
ssip_slave_start_tx(struct hsi_client * master)340 int ssip_slave_start_tx(struct hsi_client *master)
341 {
342 struct ssi_protocol *ssi = hsi_client_drvdata(master);
343
344 dev_dbg(&master->device, "start TX %d\n", atomic_read(&ssi->tx_usecnt));
345 spin_lock_bh(&ssi->lock);
346 if (ssi->send_state == SEND_IDLE) {
347 ssip_set_txstate(ssi, WAIT4READY);
348 hsi_start_tx(master);
349 }
350 spin_unlock_bh(&ssi->lock);
351 atomic_inc(&ssi->tx_usecnt);
352
353 return 0;
354 }
355 EXPORT_SYMBOL_GPL(ssip_slave_start_tx);
356
ssip_slave_stop_tx(struct hsi_client * master)357 int ssip_slave_stop_tx(struct hsi_client *master)
358 {
359 struct ssi_protocol *ssi = hsi_client_drvdata(master);
360
361 WARN_ON_ONCE(atomic_read(&ssi->tx_usecnt) == 0);
362
363 if (atomic_dec_and_test(&ssi->tx_usecnt)) {
364 spin_lock_bh(&ssi->lock);
365 if ((ssi->send_state == SEND_READY) ||
366 (ssi->send_state == WAIT4READY)) {
367 ssip_set_txstate(ssi, SEND_IDLE);
368 hsi_stop_tx(master);
369 }
370 spin_unlock_bh(&ssi->lock);
371 }
372 dev_dbg(&master->device, "stop TX %d\n", atomic_read(&ssi->tx_usecnt));
373
374 return 0;
375 }
376 EXPORT_SYMBOL_GPL(ssip_slave_stop_tx);
377
ssip_slave_running(struct hsi_client * master)378 int ssip_slave_running(struct hsi_client *master)
379 {
380 struct ssi_protocol *ssi = hsi_client_drvdata(master);
381 return netif_running(ssi->netdev);
382 }
383 EXPORT_SYMBOL_GPL(ssip_slave_running);
384
ssip_reset(struct hsi_client * cl)385 static void ssip_reset(struct hsi_client *cl)
386 {
387 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
388 struct list_head *head, *tmp;
389 struct hsi_msg *msg;
390
391 if (netif_running(ssi->netdev))
392 netif_carrier_off(ssi->netdev);
393 hsi_flush(cl);
394 spin_lock_bh(&ssi->lock);
395 if (ssi->send_state != SEND_IDLE)
396 hsi_stop_tx(cl);
397 spin_unlock_bh(&ssi->lock);
398 if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
399 ssi_waketest(cl, 0); /* FIXME: To be removed */
400 spin_lock_bh(&ssi->lock);
401 timer_delete(&ssi->rx_wd);
402 timer_delete(&ssi->tx_wd);
403 timer_delete(&ssi->keep_alive);
404 cancel_work_sync(&ssi->work);
405 ssi->main_state = 0;
406 ssi->send_state = 0;
407 ssi->recv_state = 0;
408 ssi->flags = 0;
409 ssi->rxid = 0;
410 ssi->txid = 0;
411 list_for_each_safe(head, tmp, &ssi->txqueue) {
412 msg = list_entry(head, struct hsi_msg, link);
413 dev_dbg(&cl->device, "Pending TX data\n");
414 list_del(head);
415 ssip_free_data(msg);
416 }
417 ssi->txqueue_len = 0;
418 spin_unlock_bh(&ssi->lock);
419 }
420
ssip_dump_state(struct hsi_client * cl)421 static void ssip_dump_state(struct hsi_client *cl)
422 {
423 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
424 struct hsi_msg *msg;
425
426 spin_lock_bh(&ssi->lock);
427 dev_err(&cl->device, "Main state: %d\n", ssi->main_state);
428 dev_err(&cl->device, "Recv state: %d\n", ssi->recv_state);
429 dev_err(&cl->device, "Send state: %d\n", ssi->send_state);
430 dev_err(&cl->device, "CMT %s\n", (ssi->main_state == ACTIVE) ?
431 "Online" : "Offline");
432 dev_err(&cl->device, "Wake test %d\n",
433 test_bit(SSIP_WAKETEST_FLAG, &ssi->flags));
434 dev_err(&cl->device, "Data RX id: %d\n", ssi->rxid);
435 dev_err(&cl->device, "Data TX id: %d\n", ssi->txid);
436
437 list_for_each_entry(msg, &ssi->txqueue, link)
438 dev_err(&cl->device, "pending TX data (%p)\n", msg);
439 spin_unlock_bh(&ssi->lock);
440 }
441
ssip_error(struct hsi_client * cl)442 static void ssip_error(struct hsi_client *cl)
443 {
444 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
445 struct hsi_msg *msg;
446
447 ssip_dump_state(cl);
448 ssip_reset(cl);
449 msg = ssip_claim_cmd(ssi);
450 msg->complete = ssip_rxcmd_complete;
451 hsi_async_read(cl, msg);
452 }
453
ssip_keep_alive(struct timer_list * t)454 static void ssip_keep_alive(struct timer_list *t)
455 {
456 struct ssi_protocol *ssi = from_timer(ssi, t, keep_alive);
457 struct hsi_client *cl = ssi->cl;
458
459 dev_dbg(&cl->device, "Keep alive kick in: m(%d) r(%d) s(%d)\n",
460 ssi->main_state, ssi->recv_state, ssi->send_state);
461
462 spin_lock(&ssi->lock);
463 if (ssi->recv_state == RECV_IDLE)
464 switch (ssi->send_state) {
465 case SEND_READY:
466 if (atomic_read(&ssi->tx_usecnt) == 0)
467 break;
468 fallthrough;
469 /*
470 * Workaround for cmt-speech in that case
471 * we relay on audio timers.
472 */
473 case SEND_IDLE:
474 spin_unlock(&ssi->lock);
475 return;
476 }
477 mod_timer(&ssi->keep_alive, jiffies + msecs_to_jiffies(SSIP_KATOUT));
478 spin_unlock(&ssi->lock);
479 }
480
ssip_rx_wd(struct timer_list * t)481 static void ssip_rx_wd(struct timer_list *t)
482 {
483 struct ssi_protocol *ssi = from_timer(ssi, t, rx_wd);
484 struct hsi_client *cl = ssi->cl;
485
486 dev_err(&cl->device, "Watchdog triggered\n");
487 ssip_error(cl);
488 }
489
ssip_tx_wd(struct timer_list * t)490 static void ssip_tx_wd(struct timer_list *t)
491 {
492 struct ssi_protocol *ssi = from_timer(ssi, t, tx_wd);
493 struct hsi_client *cl = ssi->cl;
494
495 dev_err(&cl->device, "Watchdog triggered\n");
496 ssip_error(cl);
497 }
498
ssip_send_bootinfo_req_cmd(struct hsi_client * cl)499 static void ssip_send_bootinfo_req_cmd(struct hsi_client *cl)
500 {
501 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
502 struct hsi_msg *msg;
503
504 dev_dbg(&cl->device, "Issuing BOOT INFO REQ command\n");
505 msg = ssip_claim_cmd(ssi);
506 ssip_set_cmd(msg, SSIP_BOOTINFO_REQ_CMD(SSIP_LOCAL_VERID));
507 msg->complete = ssip_release_cmd;
508 hsi_async_write(cl, msg);
509 dev_dbg(&cl->device, "Issuing RX command\n");
510 msg = ssip_claim_cmd(ssi);
511 msg->complete = ssip_rxcmd_complete;
512 hsi_async_read(cl, msg);
513 }
514
ssip_start_rx(struct hsi_client * cl)515 static void ssip_start_rx(struct hsi_client *cl)
516 {
517 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
518 struct hsi_msg *msg;
519
520 dev_dbg(&cl->device, "RX start M(%d) R(%d)\n", ssi->main_state,
521 ssi->recv_state);
522 spin_lock_bh(&ssi->lock);
523 /*
524 * We can have two UP events in a row due to a short low
525 * high transition. Therefore we need to ignore the sencond UP event.
526 */
527 if ((ssi->main_state != ACTIVE) || (ssi->recv_state == RECV_READY)) {
528 spin_unlock_bh(&ssi->lock);
529 return;
530 }
531 ssip_set_rxstate(ssi, RECV_READY);
532 spin_unlock_bh(&ssi->lock);
533
534 msg = ssip_claim_cmd(ssi);
535 ssip_set_cmd(msg, SSIP_READY_CMD);
536 msg->complete = ssip_release_cmd;
537 dev_dbg(&cl->device, "Send READY\n");
538 hsi_async_write(cl, msg);
539 }
540
ssip_stop_rx(struct hsi_client * cl)541 static void ssip_stop_rx(struct hsi_client *cl)
542 {
543 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
544
545 dev_dbg(&cl->device, "RX stop M(%d)\n", ssi->main_state);
546 spin_lock_bh(&ssi->lock);
547 if (likely(ssi->main_state == ACTIVE))
548 ssip_set_rxstate(ssi, RECV_IDLE);
549 spin_unlock_bh(&ssi->lock);
550 }
551
ssip_free_strans(struct hsi_msg * msg)552 static void ssip_free_strans(struct hsi_msg *msg)
553 {
554 ssip_free_data(msg->context);
555 ssip_release_cmd(msg);
556 }
557
ssip_strans_complete(struct hsi_msg * msg)558 static void ssip_strans_complete(struct hsi_msg *msg)
559 {
560 struct hsi_client *cl = msg->cl;
561 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
562 struct hsi_msg *data;
563
564 data = msg->context;
565 ssip_release_cmd(msg);
566 spin_lock_bh(&ssi->lock);
567 ssip_set_txstate(ssi, SENDING);
568 spin_unlock_bh(&ssi->lock);
569 hsi_async_write(cl, data);
570 }
571
ssip_xmit(struct hsi_client * cl)572 static int ssip_xmit(struct hsi_client *cl)
573 {
574 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
575 struct hsi_msg *msg, *dmsg;
576 struct sk_buff *skb;
577
578 spin_lock_bh(&ssi->lock);
579 if (list_empty(&ssi->txqueue)) {
580 spin_unlock_bh(&ssi->lock);
581 return 0;
582 }
583 dmsg = list_first_entry(&ssi->txqueue, struct hsi_msg, link);
584 list_del(&dmsg->link);
585 ssi->txqueue_len--;
586 spin_unlock_bh(&ssi->lock);
587
588 msg = ssip_claim_cmd(ssi);
589 skb = dmsg->context;
590 msg->context = dmsg;
591 msg->complete = ssip_strans_complete;
592 msg->destructor = ssip_free_strans;
593
594 spin_lock_bh(&ssi->lock);
595 ssip_set_cmd(msg, SSIP_START_TRANS_CMD(SSIP_BYTES_TO_FRAMES(skb->len),
596 ssi->txid));
597 ssi->txid++;
598 ssip_set_txstate(ssi, SENDING);
599 spin_unlock_bh(&ssi->lock);
600
601 dev_dbg(&cl->device, "Send STRANS (%d frames)\n",
602 SSIP_BYTES_TO_FRAMES(skb->len));
603
604 return hsi_async_write(cl, msg);
605 }
606
607 /* In soft IRQ context */
ssip_pn_rx(struct sk_buff * skb)608 static void ssip_pn_rx(struct sk_buff *skb)
609 {
610 struct net_device *dev = skb->dev;
611
612 if (unlikely(!netif_running(dev))) {
613 dev_dbg(&dev->dev, "Drop RX packet\n");
614 dev->stats.rx_dropped++;
615 dev_kfree_skb(skb);
616 return;
617 }
618 if (unlikely(!pskb_may_pull(skb, SSIP_MIN_PN_HDR))) {
619 dev_dbg(&dev->dev, "Error drop RX packet\n");
620 dev->stats.rx_errors++;
621 dev->stats.rx_length_errors++;
622 dev_kfree_skb(skb);
623 return;
624 }
625 dev->stats.rx_packets++;
626 dev->stats.rx_bytes += skb->len;
627
628 /* length field is exchanged in network byte order */
629 ((u16 *)skb->data)[2] = ntohs(((u16 *)skb->data)[2]);
630 dev_dbg(&dev->dev, "RX length fixed (%04x -> %u)\n",
631 ((u16 *)skb->data)[2], ntohs(((u16 *)skb->data)[2]));
632
633 skb->protocol = htons(ETH_P_PHONET);
634 skb_reset_mac_header(skb);
635 __skb_pull(skb, 1);
636 netif_rx(skb);
637 }
638
ssip_rx_data_complete(struct hsi_msg * msg)639 static void ssip_rx_data_complete(struct hsi_msg *msg)
640 {
641 struct hsi_client *cl = msg->cl;
642 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
643 struct sk_buff *skb;
644
645 if (msg->status == HSI_STATUS_ERROR) {
646 dev_err(&cl->device, "RX data error\n");
647 ssip_free_data(msg);
648 ssip_error(cl);
649 return;
650 }
651 timer_delete(&ssi->rx_wd); /* FIXME: Revisit */
652 skb = msg->context;
653 ssip_pn_rx(skb);
654 hsi_free_msg(msg);
655 }
656
ssip_rx_bootinforeq(struct hsi_client * cl,u32 cmd)657 static void ssip_rx_bootinforeq(struct hsi_client *cl, u32 cmd)
658 {
659 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
660 struct hsi_msg *msg;
661
662 /* Workaroud: Ignore CMT Loader message leftover */
663 if (cmd == SSIP_CMT_LOADER_SYNC)
664 return;
665
666 switch (ssi->main_state) {
667 case ACTIVE:
668 dev_err(&cl->device, "Boot info req on active state\n");
669 ssip_error(cl);
670 fallthrough;
671 case INIT:
672 case HANDSHAKE:
673 spin_lock_bh(&ssi->lock);
674 ssi->main_state = HANDSHAKE;
675 spin_unlock_bh(&ssi->lock);
676
677 if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
678 ssi_waketest(cl, 1); /* FIXME: To be removed */
679
680 spin_lock_bh(&ssi->lock);
681 /* Start boot handshake watchdog */
682 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
683 spin_unlock_bh(&ssi->lock);
684 dev_dbg(&cl->device, "Send BOOTINFO_RESP\n");
685 if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
686 dev_warn(&cl->device, "boot info req verid mismatch\n");
687 msg = ssip_claim_cmd(ssi);
688 ssip_set_cmd(msg, SSIP_BOOTINFO_RESP_CMD(SSIP_LOCAL_VERID));
689 msg->complete = ssip_release_cmd;
690 hsi_async_write(cl, msg);
691 break;
692 default:
693 dev_dbg(&cl->device, "Wrong state M(%d)\n", ssi->main_state);
694 break;
695 }
696 }
697
ssip_rx_bootinforesp(struct hsi_client * cl,u32 cmd)698 static void ssip_rx_bootinforesp(struct hsi_client *cl, u32 cmd)
699 {
700 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
701
702 if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
703 dev_warn(&cl->device, "boot info resp verid mismatch\n");
704
705 spin_lock_bh(&ssi->lock);
706 if (ssi->main_state != ACTIVE)
707 /* Use tx_wd as a boot watchdog in non ACTIVE state */
708 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
709 else
710 dev_dbg(&cl->device, "boot info resp ignored M(%d)\n",
711 ssi->main_state);
712 spin_unlock_bh(&ssi->lock);
713 }
714
ssip_rx_waketest(struct hsi_client * cl,u32 cmd)715 static void ssip_rx_waketest(struct hsi_client *cl, u32 cmd)
716 {
717 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
718 unsigned int wkres = SSIP_PAYLOAD(cmd);
719
720 spin_lock_bh(&ssi->lock);
721 if (ssi->main_state != HANDSHAKE) {
722 dev_dbg(&cl->device, "wake lines test ignored M(%d)\n",
723 ssi->main_state);
724 spin_unlock_bh(&ssi->lock);
725 return;
726 }
727 spin_unlock_bh(&ssi->lock);
728
729 if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
730 ssi_waketest(cl, 0); /* FIXME: To be removed */
731
732 spin_lock_bh(&ssi->lock);
733 ssi->main_state = ACTIVE;
734 timer_delete(&ssi->tx_wd); /* Stop boot handshake timer */
735 spin_unlock_bh(&ssi->lock);
736
737 dev_notice(&cl->device, "WAKELINES TEST %s\n",
738 wkres & SSIP_WAKETEST_FAILED ? "FAILED" : "OK");
739 if (wkres & SSIP_WAKETEST_FAILED) {
740 ssip_error(cl);
741 return;
742 }
743 dev_dbg(&cl->device, "CMT is ONLINE\n");
744 netif_wake_queue(ssi->netdev);
745 netif_carrier_on(ssi->netdev);
746 }
747
ssip_rx_ready(struct hsi_client * cl)748 static void ssip_rx_ready(struct hsi_client *cl)
749 {
750 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
751
752 spin_lock_bh(&ssi->lock);
753 if (unlikely(ssi->main_state != ACTIVE)) {
754 dev_dbg(&cl->device, "READY on wrong state: S(%d) M(%d)\n",
755 ssi->send_state, ssi->main_state);
756 spin_unlock_bh(&ssi->lock);
757 return;
758 }
759 if (ssi->send_state != WAIT4READY) {
760 dev_dbg(&cl->device, "Ignore spurious READY command\n");
761 spin_unlock_bh(&ssi->lock);
762 return;
763 }
764 ssip_set_txstate(ssi, SEND_READY);
765 spin_unlock_bh(&ssi->lock);
766 ssip_xmit(cl);
767 }
768
ssip_rx_strans(struct hsi_client * cl,u32 cmd)769 static void ssip_rx_strans(struct hsi_client *cl, u32 cmd)
770 {
771 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
772 struct sk_buff *skb;
773 struct hsi_msg *msg;
774 int len = SSIP_PDU_LENGTH(cmd);
775
776 dev_dbg(&cl->device, "RX strans: %d frames\n", len);
777 spin_lock_bh(&ssi->lock);
778 if (unlikely(ssi->main_state != ACTIVE)) {
779 dev_err(&cl->device, "START TRANS wrong state: S(%d) M(%d)\n",
780 ssi->send_state, ssi->main_state);
781 spin_unlock_bh(&ssi->lock);
782 return;
783 }
784 ssip_set_rxstate(ssi, RECEIVING);
785 if (unlikely(SSIP_MSG_ID(cmd) != ssi->rxid)) {
786 dev_err(&cl->device, "START TRANS id %d expected %d\n",
787 SSIP_MSG_ID(cmd), ssi->rxid);
788 spin_unlock_bh(&ssi->lock);
789 goto out1;
790 }
791 ssi->rxid++;
792 spin_unlock_bh(&ssi->lock);
793 skb = netdev_alloc_skb(ssi->netdev, len * 4);
794 if (unlikely(!skb)) {
795 dev_err(&cl->device, "No memory for rx skb\n");
796 goto out1;
797 }
798 skb_put(skb, len * 4);
799 msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
800 if (unlikely(!msg)) {
801 dev_err(&cl->device, "No memory for RX data msg\n");
802 goto out2;
803 }
804 msg->complete = ssip_rx_data_complete;
805 hsi_async_read(cl, msg);
806
807 return;
808 out2:
809 dev_kfree_skb(skb);
810 out1:
811 ssip_error(cl);
812 }
813
ssip_rxcmd_complete(struct hsi_msg * msg)814 static void ssip_rxcmd_complete(struct hsi_msg *msg)
815 {
816 struct hsi_client *cl = msg->cl;
817 u32 cmd = ssip_get_cmd(msg);
818 unsigned int cmdid = SSIP_COMMAND(cmd);
819
820 if (msg->status == HSI_STATUS_ERROR) {
821 dev_err(&cl->device, "RX error detected\n");
822 ssip_release_cmd(msg);
823 ssip_error(cl);
824 return;
825 }
826 hsi_async_read(cl, msg);
827 dev_dbg(&cl->device, "RX cmd: 0x%08x\n", cmd);
828 switch (cmdid) {
829 case SSIP_SW_BREAK:
830 /* Ignored */
831 break;
832 case SSIP_BOOTINFO_REQ:
833 ssip_rx_bootinforeq(cl, cmd);
834 break;
835 case SSIP_BOOTINFO_RESP:
836 ssip_rx_bootinforesp(cl, cmd);
837 break;
838 case SSIP_WAKETEST_RESULT:
839 ssip_rx_waketest(cl, cmd);
840 break;
841 case SSIP_START_TRANS:
842 ssip_rx_strans(cl, cmd);
843 break;
844 case SSIP_READY:
845 ssip_rx_ready(cl);
846 break;
847 default:
848 dev_warn(&cl->device, "command 0x%08x not supported\n", cmd);
849 break;
850 }
851 }
852
ssip_swbreak_complete(struct hsi_msg * msg)853 static void ssip_swbreak_complete(struct hsi_msg *msg)
854 {
855 struct hsi_client *cl = msg->cl;
856 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
857
858 ssip_release_cmd(msg);
859 spin_lock_bh(&ssi->lock);
860 if (list_empty(&ssi->txqueue)) {
861 if (atomic_read(&ssi->tx_usecnt)) {
862 ssip_set_txstate(ssi, SEND_READY);
863 } else {
864 ssip_set_txstate(ssi, SEND_IDLE);
865 hsi_stop_tx(cl);
866 }
867 spin_unlock_bh(&ssi->lock);
868 } else {
869 spin_unlock_bh(&ssi->lock);
870 ssip_xmit(cl);
871 }
872 netif_wake_queue(ssi->netdev);
873 }
874
ssip_tx_data_complete(struct hsi_msg * msg)875 static void ssip_tx_data_complete(struct hsi_msg *msg)
876 {
877 struct hsi_client *cl = msg->cl;
878 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
879 struct hsi_msg *cmsg;
880
881 if (msg->status == HSI_STATUS_ERROR) {
882 dev_err(&cl->device, "TX data error\n");
883 ssip_error(cl);
884 goto out;
885 }
886 spin_lock_bh(&ssi->lock);
887 if (list_empty(&ssi->txqueue)) {
888 ssip_set_txstate(ssi, SENDING_SWBREAK);
889 spin_unlock_bh(&ssi->lock);
890 cmsg = ssip_claim_cmd(ssi);
891 ssip_set_cmd(cmsg, SSIP_SWBREAK_CMD);
892 cmsg->complete = ssip_swbreak_complete;
893 dev_dbg(&cl->device, "Send SWBREAK\n");
894 hsi_async_write(cl, cmsg);
895 } else {
896 spin_unlock_bh(&ssi->lock);
897 ssip_xmit(cl);
898 }
899 out:
900 ssip_free_data(msg);
901 }
902
ssip_port_event(struct hsi_client * cl,unsigned long event)903 static void ssip_port_event(struct hsi_client *cl, unsigned long event)
904 {
905 switch (event) {
906 case HSI_EVENT_START_RX:
907 ssip_start_rx(cl);
908 break;
909 case HSI_EVENT_STOP_RX:
910 ssip_stop_rx(cl);
911 break;
912 default:
913 return;
914 }
915 }
916
ssip_pn_open(struct net_device * dev)917 static int ssip_pn_open(struct net_device *dev)
918 {
919 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
920 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
921 int err;
922
923 err = hsi_claim_port(cl, 1);
924 if (err < 0) {
925 dev_err(&cl->device, "SSI port already claimed\n");
926 return err;
927 }
928 err = hsi_register_port_event(cl, ssip_port_event);
929 if (err < 0) {
930 dev_err(&cl->device, "Register HSI port event failed (%d)\n",
931 err);
932 hsi_release_port(cl);
933 return err;
934 }
935 dev_dbg(&cl->device, "Configuring SSI port\n");
936 hsi_setup(cl);
937
938 if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
939 ssi_waketest(cl, 1); /* FIXME: To be removed */
940
941 spin_lock_bh(&ssi->lock);
942 ssi->main_state = HANDSHAKE;
943 spin_unlock_bh(&ssi->lock);
944
945 ssip_send_bootinfo_req_cmd(cl);
946
947 return 0;
948 }
949
ssip_pn_stop(struct net_device * dev)950 static int ssip_pn_stop(struct net_device *dev)
951 {
952 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
953
954 ssip_reset(cl);
955 hsi_unregister_port_event(cl);
956 hsi_release_port(cl);
957
958 return 0;
959 }
960
ssip_xmit_work(struct work_struct * work)961 static void ssip_xmit_work(struct work_struct *work)
962 {
963 struct ssi_protocol *ssi =
964 container_of(work, struct ssi_protocol, work);
965 struct hsi_client *cl = ssi->cl;
966
967 ssip_xmit(cl);
968 }
969
ssip_pn_xmit(struct sk_buff * skb,struct net_device * dev)970 static netdev_tx_t ssip_pn_xmit(struct sk_buff *skb, struct net_device *dev)
971 {
972 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
973 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
974 struct hsi_msg *msg;
975
976 if ((skb->protocol != htons(ETH_P_PHONET)) ||
977 (skb->len < SSIP_MIN_PN_HDR))
978 goto drop;
979 /* Pad to 32-bits - FIXME: Revisit*/
980 if ((skb->len & 3) && skb_pad(skb, 4 - (skb->len & 3)))
981 goto inc_dropped;
982
983 /*
984 * Modem sends Phonet messages over SSI with its own endianness.
985 * Assume that modem has the same endianness as we do.
986 */
987 if (skb_cow_head(skb, 0))
988 goto drop;
989
990 /* length field is exchanged in network byte order */
991 ((u16 *)skb->data)[2] = htons(((u16 *)skb->data)[2]);
992
993 msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
994 if (!msg) {
995 dev_dbg(&cl->device, "Dropping tx data: No memory\n");
996 goto drop;
997 }
998 msg->complete = ssip_tx_data_complete;
999
1000 spin_lock_bh(&ssi->lock);
1001 if (unlikely(ssi->main_state != ACTIVE)) {
1002 spin_unlock_bh(&ssi->lock);
1003 dev_dbg(&cl->device, "Dropping tx data: CMT is OFFLINE\n");
1004 goto drop2;
1005 }
1006 list_add_tail(&msg->link, &ssi->txqueue);
1007 ssi->txqueue_len++;
1008 if (dev->tx_queue_len < ssi->txqueue_len) {
1009 dev_info(&cl->device, "TX queue full %d\n", ssi->txqueue_len);
1010 netif_stop_queue(dev);
1011 }
1012 if (ssi->send_state == SEND_IDLE) {
1013 ssip_set_txstate(ssi, WAIT4READY);
1014 spin_unlock_bh(&ssi->lock);
1015 dev_dbg(&cl->device, "Start TX qlen %d\n", ssi->txqueue_len);
1016 hsi_start_tx(cl);
1017 } else if (ssi->send_state == SEND_READY) {
1018 /* Needed for cmt-speech workaround */
1019 dev_dbg(&cl->device, "Start TX on SEND READY qlen %d\n",
1020 ssi->txqueue_len);
1021 spin_unlock_bh(&ssi->lock);
1022 schedule_work(&ssi->work);
1023 } else {
1024 spin_unlock_bh(&ssi->lock);
1025 }
1026 dev->stats.tx_packets++;
1027 dev->stats.tx_bytes += skb->len;
1028
1029 return NETDEV_TX_OK;
1030 drop2:
1031 hsi_free_msg(msg);
1032 drop:
1033 dev_kfree_skb(skb);
1034 inc_dropped:
1035 dev->stats.tx_dropped++;
1036
1037 return NETDEV_TX_OK;
1038 }
1039
1040 /* CMT reset event handler */
ssip_reset_event(struct hsi_client * master)1041 void ssip_reset_event(struct hsi_client *master)
1042 {
1043 struct ssi_protocol *ssi = hsi_client_drvdata(master);
1044 dev_err(&ssi->cl->device, "CMT reset detected!\n");
1045 ssip_error(ssi->cl);
1046 }
1047 EXPORT_SYMBOL_GPL(ssip_reset_event);
1048
1049 static const struct net_device_ops ssip_pn_ops = {
1050 .ndo_open = ssip_pn_open,
1051 .ndo_stop = ssip_pn_stop,
1052 .ndo_start_xmit = ssip_pn_xmit,
1053 };
1054
ssip_pn_setup(struct net_device * dev)1055 static void ssip_pn_setup(struct net_device *dev)
1056 {
1057 static const u8 addr = PN_MEDIA_SOS;
1058
1059 dev->features = 0;
1060 dev->netdev_ops = &ssip_pn_ops;
1061 dev->type = ARPHRD_PHONET;
1062 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1063 dev->mtu = SSIP_DEFAULT_MTU;
1064 dev->hard_header_len = 1;
1065 dev->addr_len = 1;
1066 dev_addr_set(dev, &addr);
1067 dev->tx_queue_len = SSIP_TXQUEUE_LEN;
1068
1069 dev->needs_free_netdev = true;
1070 dev->header_ops = &phonet_header_ops;
1071 }
1072
ssi_protocol_probe(struct device * dev)1073 static int ssi_protocol_probe(struct device *dev)
1074 {
1075 static const char ifname[] = "phonet%d";
1076 struct hsi_client *cl = to_hsi_client(dev);
1077 struct ssi_protocol *ssi;
1078 int err;
1079
1080 ssi = kzalloc(sizeof(*ssi), GFP_KERNEL);
1081 if (!ssi)
1082 return -ENOMEM;
1083
1084 spin_lock_init(&ssi->lock);
1085 timer_setup(&ssi->rx_wd, ssip_rx_wd, TIMER_DEFERRABLE);
1086 timer_setup(&ssi->tx_wd, ssip_tx_wd, TIMER_DEFERRABLE);
1087 timer_setup(&ssi->keep_alive, ssip_keep_alive, 0);
1088 INIT_LIST_HEAD(&ssi->txqueue);
1089 INIT_LIST_HEAD(&ssi->cmdqueue);
1090 atomic_set(&ssi->tx_usecnt, 0);
1091 hsi_client_set_drvdata(cl, ssi);
1092 ssi->cl = cl;
1093 INIT_WORK(&ssi->work, ssip_xmit_work);
1094
1095 ssi->channel_id_cmd = hsi_get_channel_id_by_name(cl, "mcsaab-control");
1096 if (ssi->channel_id_cmd < 0) {
1097 err = ssi->channel_id_cmd;
1098 dev_err(dev, "Could not get cmd channel (%d)\n", err);
1099 goto out;
1100 }
1101
1102 ssi->channel_id_data = hsi_get_channel_id_by_name(cl, "mcsaab-data");
1103 if (ssi->channel_id_data < 0) {
1104 err = ssi->channel_id_data;
1105 dev_err(dev, "Could not get data channel (%d)\n", err);
1106 goto out;
1107 }
1108
1109 err = ssip_alloc_cmds(ssi);
1110 if (err < 0) {
1111 dev_err(dev, "No memory for commands\n");
1112 goto out;
1113 }
1114
1115 ssi->netdev = alloc_netdev(0, ifname, NET_NAME_UNKNOWN, ssip_pn_setup);
1116 if (!ssi->netdev) {
1117 dev_err(dev, "No memory for netdev\n");
1118 err = -ENOMEM;
1119 goto out1;
1120 }
1121
1122 /* MTU range: 6 - 65535 */
1123 ssi->netdev->min_mtu = PHONET_MIN_MTU;
1124 ssi->netdev->max_mtu = SSIP_MAX_MTU;
1125
1126 SET_NETDEV_DEV(ssi->netdev, dev);
1127 netif_carrier_off(ssi->netdev);
1128 err = register_netdev(ssi->netdev);
1129 if (err < 0) {
1130 dev_err(dev, "Register netdev failed (%d)\n", err);
1131 goto out2;
1132 }
1133
1134 list_add(&ssi->link, &ssip_list);
1135
1136 dev_dbg(dev, "channel configuration: cmd=%d, data=%d\n",
1137 ssi->channel_id_cmd, ssi->channel_id_data);
1138
1139 return 0;
1140 out2:
1141 free_netdev(ssi->netdev);
1142 out1:
1143 ssip_free_cmds(ssi);
1144 out:
1145 kfree(ssi);
1146
1147 return err;
1148 }
1149
ssi_protocol_remove(struct device * dev)1150 static int ssi_protocol_remove(struct device *dev)
1151 {
1152 struct hsi_client *cl = to_hsi_client(dev);
1153 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
1154
1155 list_del(&ssi->link);
1156 unregister_netdev(ssi->netdev);
1157 ssip_free_cmds(ssi);
1158 hsi_client_set_drvdata(cl, NULL);
1159 kfree(ssi);
1160
1161 return 0;
1162 }
1163
1164 static struct hsi_client_driver ssip_driver = {
1165 .driver = {
1166 .name = "ssi-protocol",
1167 .owner = THIS_MODULE,
1168 .probe = ssi_protocol_probe,
1169 .remove = ssi_protocol_remove,
1170 },
1171 };
1172
ssip_init(void)1173 static int __init ssip_init(void)
1174 {
1175 pr_info("SSI protocol aka McSAAB added\n");
1176
1177 return hsi_register_client_driver(&ssip_driver);
1178 }
1179 module_init(ssip_init);
1180
ssip_exit(void)1181 static void __exit ssip_exit(void)
1182 {
1183 hsi_unregister_client_driver(&ssip_driver);
1184 pr_info("SSI protocol driver removed\n");
1185 }
1186 module_exit(ssip_exit);
1187
1188 MODULE_ALIAS("hsi:ssi-protocol");
1189 MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
1190 MODULE_AUTHOR("Remi Denis-Courmont <remi.denis-courmont@nokia.com>");
1191 MODULE_DESCRIPTION("SSI protocol improved aka McSAAB");
1192 MODULE_LICENSE("GPL");
1193