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 #define SSIP_TXQUEUE_LEN 100
36 #define SSIP_MAX_MTU 65535
37 #define SSIP_DEFAULT_MTU 4000
38 #define PN_MEDIA_SOS 21
39 #define SSIP_MIN_PN_HDR 6 /* FIXME: Revisit */
40 #define SSIP_WDTOUT 2000 /* FIXME: has to be 500 msecs */
41 #define SSIP_KATOUT 15 /* 15 msecs */
42 #define SSIP_MAX_CMDS 5 /* Number of pre-allocated commands buffers */
43 #define SSIP_BYTES_TO_FRAMES(x) ((((x) - 1) >> 2) + 1)
44 #define SSIP_CMT_LOADER_SYNC 0x11223344
45 /*
46 * SSI protocol command definitions
47 */
48 #define SSIP_COMMAND(data) ((data) >> 28)
49 #define SSIP_PAYLOAD(data) ((data) & 0xfffffff)
50 /* Commands */
51 #define SSIP_SW_BREAK 0
52 #define SSIP_BOOTINFO_REQ 1
53 #define SSIP_BOOTINFO_RESP 2
54 #define SSIP_WAKETEST_RESULT 3
55 #define SSIP_START_TRANS 4
56 #define SSIP_READY 5
57 /* Payloads */
58 #define SSIP_DATA_VERSION(data) ((data) & 0xff)
59 #define SSIP_LOCAL_VERID 1
60 #define SSIP_WAKETEST_OK 0
61 #define SSIP_WAKETEST_FAILED 1
62 #define SSIP_PDU_LENGTH(data) (((data) >> 8) & 0xffff)
63 #define SSIP_MSG_ID(data) ((data) & 0xff)
64 /* Generic Command */
65 #define SSIP_CMD(cmd, payload) (((cmd) << 28) | ((payload) & 0xfffffff))
66 /* Commands for the control channel */
67 #define SSIP_BOOTINFO_REQ_CMD(ver) \
68 SSIP_CMD(SSIP_BOOTINFO_REQ, SSIP_DATA_VERSION(ver))
69 #define SSIP_BOOTINFO_RESP_CMD(ver) \
70 SSIP_CMD(SSIP_BOOTINFO_RESP, SSIP_DATA_VERSION(ver))
71 #define SSIP_START_TRANS_CMD(pdulen, id) \
72 SSIP_CMD(SSIP_START_TRANS, (((pdulen) << 8) | SSIP_MSG_ID(id)))
73 #define SSIP_READY_CMD SSIP_CMD(SSIP_READY, 0)
74 #define SSIP_SWBREAK_CMD SSIP_CMD(SSIP_SW_BREAK, 0)
75
76 #define SSIP_WAKETEST_FLAG 0
77
78 /* Main state machine states */
79 enum {
80 INIT,
81 HANDSHAKE,
82 ACTIVE,
83 };
84
85 /* Send state machine states */
86 enum {
87 SEND_IDLE,
88 WAIT4READY,
89 SEND_READY,
90 SENDING,
91 SENDING_SWBREAK,
92 };
93
94 /* Receive state machine states */
95 enum {
96 RECV_IDLE,
97 RECV_READY,
98 RECEIVING,
99 };
100
101 /**
102 * struct ssi_protocol - SSI protocol (McSAAB) data
103 * @main_state: Main state machine
104 * @send_state: TX state machine
105 * @recv_state: RX state machine
106 * @flags: Flags, currently only used to follow wake line test
107 * @rxid: RX data id
108 * @txid: TX data id
109 * @txqueue_len: TX queue length
110 * @tx_wd: TX watchdog
111 * @rx_wd: RX watchdog
112 * @keep_alive: Workaround for SSI HW bug
113 * @lock: To serialize access to this struct
114 * @netdev: Phonet network device
115 * @txqueue: TX data queue
116 * @cmdqueue: Queue of free commands
117 * @cl: HSI client own reference
118 * @link: Link for ssip_list
119 * @tx_usecount: 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 del_timer(&ssi->rx_wd);
285 if (ssi->send_state == SEND_IDLE)
286 del_timer(&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 del_timer(&ssi->tx_wd);
310 if (ssi->recv_state == RECV_IDLE)
311 del_timer(&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 del_timer(&ssi->rx_wd);
402 del_timer(&ssi->tx_wd);
403 del_timer(&ssi->keep_alive);
404 ssi->main_state = 0;
405 ssi->send_state = 0;
406 ssi->recv_state = 0;
407 ssi->flags = 0;
408 ssi->rxid = 0;
409 ssi->txid = 0;
410 list_for_each_safe(head, tmp, &ssi->txqueue) {
411 msg = list_entry(head, struct hsi_msg, link);
412 dev_dbg(&cl->device, "Pending TX data\n");
413 list_del(head);
414 ssip_free_data(msg);
415 }
416 ssi->txqueue_len = 0;
417 spin_unlock_bh(&ssi->lock);
418 }
419
ssip_dump_state(struct hsi_client * cl)420 static void ssip_dump_state(struct hsi_client *cl)
421 {
422 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
423 struct hsi_msg *msg;
424
425 spin_lock_bh(&ssi->lock);
426 dev_err(&cl->device, "Main state: %d\n", ssi->main_state);
427 dev_err(&cl->device, "Recv state: %d\n", ssi->recv_state);
428 dev_err(&cl->device, "Send state: %d\n", ssi->send_state);
429 dev_err(&cl->device, "CMT %s\n", (ssi->main_state == ACTIVE) ?
430 "Online" : "Offline");
431 dev_err(&cl->device, "Wake test %d\n",
432 test_bit(SSIP_WAKETEST_FLAG, &ssi->flags));
433 dev_err(&cl->device, "Data RX id: %d\n", ssi->rxid);
434 dev_err(&cl->device, "Data TX id: %d\n", ssi->txid);
435
436 list_for_each_entry(msg, &ssi->txqueue, link)
437 dev_err(&cl->device, "pending TX data (%p)\n", msg);
438 spin_unlock_bh(&ssi->lock);
439 }
440
ssip_error(struct hsi_client * cl)441 static void ssip_error(struct hsi_client *cl)
442 {
443 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
444 struct hsi_msg *msg;
445
446 ssip_dump_state(cl);
447 ssip_reset(cl);
448 msg = ssip_claim_cmd(ssi);
449 msg->complete = ssip_rxcmd_complete;
450 hsi_async_read(cl, msg);
451 }
452
ssip_keep_alive(struct timer_list * t)453 static void ssip_keep_alive(struct timer_list *t)
454 {
455 struct ssi_protocol *ssi = from_timer(ssi, t, keep_alive);
456 struct hsi_client *cl = ssi->cl;
457
458 dev_dbg(&cl->device, "Keep alive kick in: m(%d) r(%d) s(%d)\n",
459 ssi->main_state, ssi->recv_state, ssi->send_state);
460
461 spin_lock(&ssi->lock);
462 if (ssi->recv_state == RECV_IDLE)
463 switch (ssi->send_state) {
464 case SEND_READY:
465 if (atomic_read(&ssi->tx_usecnt) == 0)
466 break;
467 fallthrough;
468 /*
469 * Workaround for cmt-speech in that case
470 * we relay on audio timers.
471 */
472 case SEND_IDLE:
473 spin_unlock(&ssi->lock);
474 return;
475 }
476 mod_timer(&ssi->keep_alive, jiffies + msecs_to_jiffies(SSIP_KATOUT));
477 spin_unlock(&ssi->lock);
478 }
479
ssip_rx_wd(struct timer_list * t)480 static void ssip_rx_wd(struct timer_list *t)
481 {
482 struct ssi_protocol *ssi = from_timer(ssi, t, rx_wd);
483 struct hsi_client *cl = ssi->cl;
484
485 dev_err(&cl->device, "Watchdog triggered\n");
486 ssip_error(cl);
487 }
488
ssip_tx_wd(struct timer_list * t)489 static void ssip_tx_wd(struct timer_list *t)
490 {
491 struct ssi_protocol *ssi = from_timer(ssi, t, tx_wd);
492 struct hsi_client *cl = ssi->cl;
493
494 dev_err(&cl->device, "Watchdog triggered\n");
495 ssip_error(cl);
496 }
497
ssip_send_bootinfo_req_cmd(struct hsi_client * cl)498 static void ssip_send_bootinfo_req_cmd(struct hsi_client *cl)
499 {
500 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
501 struct hsi_msg *msg;
502
503 dev_dbg(&cl->device, "Issuing BOOT INFO REQ command\n");
504 msg = ssip_claim_cmd(ssi);
505 ssip_set_cmd(msg, SSIP_BOOTINFO_REQ_CMD(SSIP_LOCAL_VERID));
506 msg->complete = ssip_release_cmd;
507 hsi_async_write(cl, msg);
508 dev_dbg(&cl->device, "Issuing RX command\n");
509 msg = ssip_claim_cmd(ssi);
510 msg->complete = ssip_rxcmd_complete;
511 hsi_async_read(cl, msg);
512 }
513
ssip_start_rx(struct hsi_client * cl)514 static void ssip_start_rx(struct hsi_client *cl)
515 {
516 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
517 struct hsi_msg *msg;
518
519 dev_dbg(&cl->device, "RX start M(%d) R(%d)\n", ssi->main_state,
520 ssi->recv_state);
521 spin_lock_bh(&ssi->lock);
522 /*
523 * We can have two UP events in a row due to a short low
524 * high transition. Therefore we need to ignore the sencond UP event.
525 */
526 if ((ssi->main_state != ACTIVE) || (ssi->recv_state == RECV_READY)) {
527 spin_unlock_bh(&ssi->lock);
528 return;
529 }
530 ssip_set_rxstate(ssi, RECV_READY);
531 spin_unlock_bh(&ssi->lock);
532
533 msg = ssip_claim_cmd(ssi);
534 ssip_set_cmd(msg, SSIP_READY_CMD);
535 msg->complete = ssip_release_cmd;
536 dev_dbg(&cl->device, "Send READY\n");
537 hsi_async_write(cl, msg);
538 }
539
ssip_stop_rx(struct hsi_client * cl)540 static void ssip_stop_rx(struct hsi_client *cl)
541 {
542 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
543
544 dev_dbg(&cl->device, "RX stop M(%d)\n", ssi->main_state);
545 spin_lock_bh(&ssi->lock);
546 if (likely(ssi->main_state == ACTIVE))
547 ssip_set_rxstate(ssi, RECV_IDLE);
548 spin_unlock_bh(&ssi->lock);
549 }
550
ssip_free_strans(struct hsi_msg * msg)551 static void ssip_free_strans(struct hsi_msg *msg)
552 {
553 ssip_free_data(msg->context);
554 ssip_release_cmd(msg);
555 }
556
ssip_strans_complete(struct hsi_msg * msg)557 static void ssip_strans_complete(struct hsi_msg *msg)
558 {
559 struct hsi_client *cl = msg->cl;
560 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
561 struct hsi_msg *data;
562
563 data = msg->context;
564 ssip_release_cmd(msg);
565 spin_lock_bh(&ssi->lock);
566 ssip_set_txstate(ssi, SENDING);
567 spin_unlock_bh(&ssi->lock);
568 hsi_async_write(cl, data);
569 }
570
ssip_xmit(struct hsi_client * cl)571 static int ssip_xmit(struct hsi_client *cl)
572 {
573 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
574 struct hsi_msg *msg, *dmsg;
575 struct sk_buff *skb;
576
577 spin_lock_bh(&ssi->lock);
578 if (list_empty(&ssi->txqueue)) {
579 spin_unlock_bh(&ssi->lock);
580 return 0;
581 }
582 dmsg = list_first_entry(&ssi->txqueue, struct hsi_msg, link);
583 list_del(&dmsg->link);
584 ssi->txqueue_len--;
585 spin_unlock_bh(&ssi->lock);
586
587 msg = ssip_claim_cmd(ssi);
588 skb = dmsg->context;
589 msg->context = dmsg;
590 msg->complete = ssip_strans_complete;
591 msg->destructor = ssip_free_strans;
592
593 spin_lock_bh(&ssi->lock);
594 ssip_set_cmd(msg, SSIP_START_TRANS_CMD(SSIP_BYTES_TO_FRAMES(skb->len),
595 ssi->txid));
596 ssi->txid++;
597 ssip_set_txstate(ssi, SENDING);
598 spin_unlock_bh(&ssi->lock);
599
600 dev_dbg(&cl->device, "Send STRANS (%d frames)\n",
601 SSIP_BYTES_TO_FRAMES(skb->len));
602
603 return hsi_async_write(cl, msg);
604 }
605
606 /* In soft IRQ context */
ssip_pn_rx(struct sk_buff * skb)607 static void ssip_pn_rx(struct sk_buff *skb)
608 {
609 struct net_device *dev = skb->dev;
610
611 if (unlikely(!netif_running(dev))) {
612 dev_dbg(&dev->dev, "Drop RX packet\n");
613 dev->stats.rx_dropped++;
614 dev_kfree_skb(skb);
615 return;
616 }
617 if (unlikely(!pskb_may_pull(skb, SSIP_MIN_PN_HDR))) {
618 dev_dbg(&dev->dev, "Error drop RX packet\n");
619 dev->stats.rx_errors++;
620 dev->stats.rx_length_errors++;
621 dev_kfree_skb(skb);
622 return;
623 }
624 dev->stats.rx_packets++;
625 dev->stats.rx_bytes += skb->len;
626
627 /* length field is exchanged in network byte order */
628 ((u16 *)skb->data)[2] = ntohs(((u16 *)skb->data)[2]);
629 dev_dbg(&dev->dev, "RX length fixed (%04x -> %u)\n",
630 ((u16 *)skb->data)[2], ntohs(((u16 *)skb->data)[2]));
631
632 skb->protocol = htons(ETH_P_PHONET);
633 skb_reset_mac_header(skb);
634 __skb_pull(skb, 1);
635 netif_rx(skb);
636 }
637
ssip_rx_data_complete(struct hsi_msg * msg)638 static void ssip_rx_data_complete(struct hsi_msg *msg)
639 {
640 struct hsi_client *cl = msg->cl;
641 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
642 struct sk_buff *skb;
643
644 if (msg->status == HSI_STATUS_ERROR) {
645 dev_err(&cl->device, "RX data error\n");
646 ssip_free_data(msg);
647 ssip_error(cl);
648 return;
649 }
650 del_timer(&ssi->rx_wd); /* FIXME: Revisit */
651 skb = msg->context;
652 ssip_pn_rx(skb);
653 hsi_free_msg(msg);
654 }
655
ssip_rx_bootinforeq(struct hsi_client * cl,u32 cmd)656 static void ssip_rx_bootinforeq(struct hsi_client *cl, u32 cmd)
657 {
658 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
659 struct hsi_msg *msg;
660
661 /* Workaroud: Ignore CMT Loader message leftover */
662 if (cmd == SSIP_CMT_LOADER_SYNC)
663 return;
664
665 switch (ssi->main_state) {
666 case ACTIVE:
667 dev_err(&cl->device, "Boot info req on active state\n");
668 ssip_error(cl);
669 fallthrough;
670 case INIT:
671 case HANDSHAKE:
672 spin_lock_bh(&ssi->lock);
673 ssi->main_state = HANDSHAKE;
674 spin_unlock_bh(&ssi->lock);
675
676 if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
677 ssi_waketest(cl, 1); /* FIXME: To be removed */
678
679 spin_lock_bh(&ssi->lock);
680 /* Start boot handshake watchdog */
681 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
682 spin_unlock_bh(&ssi->lock);
683 dev_dbg(&cl->device, "Send BOOTINFO_RESP\n");
684 if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
685 dev_warn(&cl->device, "boot info req verid mismatch\n");
686 msg = ssip_claim_cmd(ssi);
687 ssip_set_cmd(msg, SSIP_BOOTINFO_RESP_CMD(SSIP_LOCAL_VERID));
688 msg->complete = ssip_release_cmd;
689 hsi_async_write(cl, msg);
690 break;
691 default:
692 dev_dbg(&cl->device, "Wrong state M(%d)\n", ssi->main_state);
693 break;
694 }
695 }
696
ssip_rx_bootinforesp(struct hsi_client * cl,u32 cmd)697 static void ssip_rx_bootinforesp(struct hsi_client *cl, u32 cmd)
698 {
699 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
700
701 if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
702 dev_warn(&cl->device, "boot info resp verid mismatch\n");
703
704 spin_lock_bh(&ssi->lock);
705 if (ssi->main_state != ACTIVE)
706 /* Use tx_wd as a boot watchdog in non ACTIVE state */
707 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
708 else
709 dev_dbg(&cl->device, "boot info resp ignored M(%d)\n",
710 ssi->main_state);
711 spin_unlock_bh(&ssi->lock);
712 }
713
ssip_rx_waketest(struct hsi_client * cl,u32 cmd)714 static void ssip_rx_waketest(struct hsi_client *cl, u32 cmd)
715 {
716 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
717 unsigned int wkres = SSIP_PAYLOAD(cmd);
718
719 spin_lock_bh(&ssi->lock);
720 if (ssi->main_state != HANDSHAKE) {
721 dev_dbg(&cl->device, "wake lines test ignored M(%d)\n",
722 ssi->main_state);
723 spin_unlock_bh(&ssi->lock);
724 return;
725 }
726 spin_unlock_bh(&ssi->lock);
727
728 if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
729 ssi_waketest(cl, 0); /* FIXME: To be removed */
730
731 spin_lock_bh(&ssi->lock);
732 ssi->main_state = ACTIVE;
733 del_timer(&ssi->tx_wd); /* Stop boot handshake timer */
734 spin_unlock_bh(&ssi->lock);
735
736 dev_notice(&cl->device, "WAKELINES TEST %s\n",
737 wkres & SSIP_WAKETEST_FAILED ? "FAILED" : "OK");
738 if (wkres & SSIP_WAKETEST_FAILED) {
739 ssip_error(cl);
740 return;
741 }
742 dev_dbg(&cl->device, "CMT is ONLINE\n");
743 netif_wake_queue(ssi->netdev);
744 netif_carrier_on(ssi->netdev);
745 }
746
ssip_rx_ready(struct hsi_client * cl)747 static void ssip_rx_ready(struct hsi_client *cl)
748 {
749 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
750
751 spin_lock_bh(&ssi->lock);
752 if (unlikely(ssi->main_state != ACTIVE)) {
753 dev_dbg(&cl->device, "READY on wrong state: S(%d) M(%d)\n",
754 ssi->send_state, ssi->main_state);
755 spin_unlock_bh(&ssi->lock);
756 return;
757 }
758 if (ssi->send_state != WAIT4READY) {
759 dev_dbg(&cl->device, "Ignore spurious READY command\n");
760 spin_unlock_bh(&ssi->lock);
761 return;
762 }
763 ssip_set_txstate(ssi, SEND_READY);
764 spin_unlock_bh(&ssi->lock);
765 ssip_xmit(cl);
766 }
767
ssip_rx_strans(struct hsi_client * cl,u32 cmd)768 static void ssip_rx_strans(struct hsi_client *cl, u32 cmd)
769 {
770 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
771 struct sk_buff *skb;
772 struct hsi_msg *msg;
773 int len = SSIP_PDU_LENGTH(cmd);
774
775 dev_dbg(&cl->device, "RX strans: %d frames\n", len);
776 spin_lock_bh(&ssi->lock);
777 if (unlikely(ssi->main_state != ACTIVE)) {
778 dev_err(&cl->device, "START TRANS wrong state: S(%d) M(%d)\n",
779 ssi->send_state, ssi->main_state);
780 spin_unlock_bh(&ssi->lock);
781 return;
782 }
783 ssip_set_rxstate(ssi, RECEIVING);
784 if (unlikely(SSIP_MSG_ID(cmd) != ssi->rxid)) {
785 dev_err(&cl->device, "START TRANS id %d expected %d\n",
786 SSIP_MSG_ID(cmd), ssi->rxid);
787 spin_unlock_bh(&ssi->lock);
788 goto out1;
789 }
790 ssi->rxid++;
791 spin_unlock_bh(&ssi->lock);
792 skb = netdev_alloc_skb(ssi->netdev, len * 4);
793 if (unlikely(!skb)) {
794 dev_err(&cl->device, "No memory for rx skb\n");
795 goto out1;
796 }
797 skb_put(skb, len * 4);
798 msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
799 if (unlikely(!msg)) {
800 dev_err(&cl->device, "No memory for RX data msg\n");
801 goto out2;
802 }
803 msg->complete = ssip_rx_data_complete;
804 hsi_async_read(cl, msg);
805
806 return;
807 out2:
808 dev_kfree_skb(skb);
809 out1:
810 ssip_error(cl);
811 }
812
ssip_rxcmd_complete(struct hsi_msg * msg)813 static void ssip_rxcmd_complete(struct hsi_msg *msg)
814 {
815 struct hsi_client *cl = msg->cl;
816 u32 cmd = ssip_get_cmd(msg);
817 unsigned int cmdid = SSIP_COMMAND(cmd);
818
819 if (msg->status == HSI_STATUS_ERROR) {
820 dev_err(&cl->device, "RX error detected\n");
821 ssip_release_cmd(msg);
822 ssip_error(cl);
823 return;
824 }
825 hsi_async_read(cl, msg);
826 dev_dbg(&cl->device, "RX cmd: 0x%08x\n", cmd);
827 switch (cmdid) {
828 case SSIP_SW_BREAK:
829 /* Ignored */
830 break;
831 case SSIP_BOOTINFO_REQ:
832 ssip_rx_bootinforeq(cl, cmd);
833 break;
834 case SSIP_BOOTINFO_RESP:
835 ssip_rx_bootinforesp(cl, cmd);
836 break;
837 case SSIP_WAKETEST_RESULT:
838 ssip_rx_waketest(cl, cmd);
839 break;
840 case SSIP_START_TRANS:
841 ssip_rx_strans(cl, cmd);
842 break;
843 case SSIP_READY:
844 ssip_rx_ready(cl);
845 break;
846 default:
847 dev_warn(&cl->device, "command 0x%08x not supported\n", cmd);
848 break;
849 }
850 }
851
ssip_swbreak_complete(struct hsi_msg * msg)852 static void ssip_swbreak_complete(struct hsi_msg *msg)
853 {
854 struct hsi_client *cl = msg->cl;
855 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
856
857 ssip_release_cmd(msg);
858 spin_lock_bh(&ssi->lock);
859 if (list_empty(&ssi->txqueue)) {
860 if (atomic_read(&ssi->tx_usecnt)) {
861 ssip_set_txstate(ssi, SEND_READY);
862 } else {
863 ssip_set_txstate(ssi, SEND_IDLE);
864 hsi_stop_tx(cl);
865 }
866 spin_unlock_bh(&ssi->lock);
867 } else {
868 spin_unlock_bh(&ssi->lock);
869 ssip_xmit(cl);
870 }
871 netif_wake_queue(ssi->netdev);
872 }
873
ssip_tx_data_complete(struct hsi_msg * msg)874 static void ssip_tx_data_complete(struct hsi_msg *msg)
875 {
876 struct hsi_client *cl = msg->cl;
877 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
878 struct hsi_msg *cmsg;
879
880 if (msg->status == HSI_STATUS_ERROR) {
881 dev_err(&cl->device, "TX data error\n");
882 ssip_error(cl);
883 goto out;
884 }
885 spin_lock_bh(&ssi->lock);
886 if (list_empty(&ssi->txqueue)) {
887 ssip_set_txstate(ssi, SENDING_SWBREAK);
888 spin_unlock_bh(&ssi->lock);
889 cmsg = ssip_claim_cmd(ssi);
890 ssip_set_cmd(cmsg, SSIP_SWBREAK_CMD);
891 cmsg->complete = ssip_swbreak_complete;
892 dev_dbg(&cl->device, "Send SWBREAK\n");
893 hsi_async_write(cl, cmsg);
894 } else {
895 spin_unlock_bh(&ssi->lock);
896 ssip_xmit(cl);
897 }
898 out:
899 ssip_free_data(msg);
900 }
901
ssip_port_event(struct hsi_client * cl,unsigned long event)902 static void ssip_port_event(struct hsi_client *cl, unsigned long event)
903 {
904 switch (event) {
905 case HSI_EVENT_START_RX:
906 ssip_start_rx(cl);
907 break;
908 case HSI_EVENT_STOP_RX:
909 ssip_stop_rx(cl);
910 break;
911 default:
912 return;
913 }
914 }
915
ssip_pn_open(struct net_device * dev)916 static int ssip_pn_open(struct net_device *dev)
917 {
918 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
919 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
920 int err;
921
922 err = hsi_claim_port(cl, 1);
923 if (err < 0) {
924 dev_err(&cl->device, "SSI port already claimed\n");
925 return err;
926 }
927 err = hsi_register_port_event(cl, ssip_port_event);
928 if (err < 0) {
929 dev_err(&cl->device, "Register HSI port event failed (%d)\n",
930 err);
931 hsi_release_port(cl);
932 return err;
933 }
934 dev_dbg(&cl->device, "Configuring SSI port\n");
935 hsi_setup(cl);
936
937 if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
938 ssi_waketest(cl, 1); /* FIXME: To be removed */
939
940 spin_lock_bh(&ssi->lock);
941 ssi->main_state = HANDSHAKE;
942 spin_unlock_bh(&ssi->lock);
943
944 ssip_send_bootinfo_req_cmd(cl);
945
946 return 0;
947 }
948
ssip_pn_stop(struct net_device * dev)949 static int ssip_pn_stop(struct net_device *dev)
950 {
951 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
952
953 ssip_reset(cl);
954 hsi_unregister_port_event(cl);
955 hsi_release_port(cl);
956
957 return 0;
958 }
959
ssip_xmit_work(struct work_struct * work)960 static void ssip_xmit_work(struct work_struct *work)
961 {
962 struct ssi_protocol *ssi =
963 container_of(work, struct ssi_protocol, work);
964 struct hsi_client *cl = ssi->cl;
965
966 ssip_xmit(cl);
967 }
968
ssip_pn_xmit(struct sk_buff * skb,struct net_device * dev)969 static netdev_tx_t ssip_pn_xmit(struct sk_buff *skb, struct net_device *dev)
970 {
971 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
972 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
973 struct hsi_msg *msg;
974
975 if ((skb->protocol != htons(ETH_P_PHONET)) ||
976 (skb->len < SSIP_MIN_PN_HDR))
977 goto drop;
978 /* Pad to 32-bits - FIXME: Revisit*/
979 if ((skb->len & 3) && skb_pad(skb, 4 - (skb->len & 3)))
980 goto inc_dropped;
981
982 /*
983 * Modem sends Phonet messages over SSI with its own endianness.
984 * Assume that modem has the same endianness as we do.
985 */
986 if (skb_cow_head(skb, 0))
987 goto drop;
988
989 /* length field is exchanged in network byte order */
990 ((u16 *)skb->data)[2] = htons(((u16 *)skb->data)[2]);
991
992 msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
993 if (!msg) {
994 dev_dbg(&cl->device, "Dropping tx data: No memory\n");
995 goto drop;
996 }
997 msg->complete = ssip_tx_data_complete;
998
999 spin_lock_bh(&ssi->lock);
1000 if (unlikely(ssi->main_state != ACTIVE)) {
1001 spin_unlock_bh(&ssi->lock);
1002 dev_dbg(&cl->device, "Dropping tx data: CMT is OFFLINE\n");
1003 goto drop2;
1004 }
1005 list_add_tail(&msg->link, &ssi->txqueue);
1006 ssi->txqueue_len++;
1007 if (dev->tx_queue_len < ssi->txqueue_len) {
1008 dev_info(&cl->device, "TX queue full %d\n", ssi->txqueue_len);
1009 netif_stop_queue(dev);
1010 }
1011 if (ssi->send_state == SEND_IDLE) {
1012 ssip_set_txstate(ssi, WAIT4READY);
1013 spin_unlock_bh(&ssi->lock);
1014 dev_dbg(&cl->device, "Start TX qlen %d\n", ssi->txqueue_len);
1015 hsi_start_tx(cl);
1016 } else if (ssi->send_state == SEND_READY) {
1017 /* Needed for cmt-speech workaround */
1018 dev_dbg(&cl->device, "Start TX on SEND READY qlen %d\n",
1019 ssi->txqueue_len);
1020 spin_unlock_bh(&ssi->lock);
1021 schedule_work(&ssi->work);
1022 } else {
1023 spin_unlock_bh(&ssi->lock);
1024 }
1025 dev->stats.tx_packets++;
1026 dev->stats.tx_bytes += skb->len;
1027
1028 return NETDEV_TX_OK;
1029 drop2:
1030 hsi_free_msg(msg);
1031 drop:
1032 dev_kfree_skb(skb);
1033 inc_dropped:
1034 dev->stats.tx_dropped++;
1035
1036 return NETDEV_TX_OK;
1037 }
1038
1039 /* CMT reset event handler */
ssip_reset_event(struct hsi_client * master)1040 void ssip_reset_event(struct hsi_client *master)
1041 {
1042 struct ssi_protocol *ssi = hsi_client_drvdata(master);
1043 dev_err(&ssi->cl->device, "CMT reset detected!\n");
1044 ssip_error(ssi->cl);
1045 }
1046 EXPORT_SYMBOL_GPL(ssip_reset_event);
1047
1048 static const struct net_device_ops ssip_pn_ops = {
1049 .ndo_open = ssip_pn_open,
1050 .ndo_stop = ssip_pn_stop,
1051 .ndo_start_xmit = ssip_pn_xmit,
1052 };
1053
ssip_pn_setup(struct net_device * dev)1054 static void ssip_pn_setup(struct net_device *dev)
1055 {
1056 static const u8 addr = PN_MEDIA_SOS;
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->addr_len = 1;
1065 dev_addr_set(dev, &addr);
1066 dev->tx_queue_len = SSIP_TXQUEUE_LEN;
1067
1068 dev->needs_free_netdev = true;
1069 dev->header_ops = &phonet_header_ops;
1070 }
1071
ssi_protocol_probe(struct device * dev)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
ssi_protocol_remove(struct device * dev)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
ssip_init(void)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
ssip_exit(void)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");
1192