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iio: ep93xx: remove redundant return value check of platform_get_resource()
[linux-2.6/btrfs-unstable.git] / drivers / hsi / clients / ssi_protocol.c
blob9b167bc6eee48ca498a070ca46cc09836f02d8c1
1 /*
2 * ssi_protocol.c
3 *
4 * Implementation of the SSI McSAAB improved protocol.
5 *
6 * Copyright (C) 2010 Nokia Corporation. All rights reserved.
7 * Copyright (C) 2013 Sebastian Reichel <sre@kernel.org>
8 *
9 * Contact: Carlos Chinea <carlos.chinea@nokia.com>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * version 2 as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
23 * 02110-1301 USA
24 */
25
26 #include <linux/atomic.h>
27 #include <linux/clk.h>
28 #include <linux/device.h>
29 #include <linux/err.h>
30 #include <linux/gpio.h>
31 #include <linux/if_ether.h>
32 #include <linux/if_arp.h>
33 #include <linux/if_phonet.h>
34 #include <linux/init.h>
35 #include <linux/irq.h>
36 #include <linux/list.h>
37 #include <linux/module.h>
38 #include <linux/netdevice.h>
39 #include <linux/notifier.h>
40 #include <linux/scatterlist.h>
41 #include <linux/skbuff.h>
42 #include <linux/slab.h>
43 #include <linux/spinlock.h>
44 #include <linux/timer.h>
45 #include <linux/hsi/hsi.h>
46 #include <linux/hsi/ssi_protocol.h>
47
48 void ssi_waketest(struct hsi_client *cl, unsigned int enable);
49
50 #define SSIP_TXQUEUE_LEN 100
51 #define SSIP_MAX_MTU 65535
52 #define SSIP_DEFAULT_MTU 4000
53 #define PN_MEDIA_SOS 21
54 #define SSIP_MIN_PN_HDR 6 /* FIXME: Revisit */
55 #define SSIP_WDTOUT 2000 /* FIXME: has to be 500 msecs */
56 #define SSIP_KATOUT 15 /* 15 msecs */
57 #define SSIP_MAX_CMDS 5 /* Number of pre-allocated commands buffers */
58 #define SSIP_BYTES_TO_FRAMES(x) ((((x) - 1) >> 2) + 1)
59 #define SSIP_CMT_LOADER_SYNC 0x11223344
60 /*
61 * SSI protocol command definitions
62 */
63 #define SSIP_COMMAND(data) ((data) >> 28)
64 #define SSIP_PAYLOAD(data) ((data) & 0xfffffff)
65 /* Commands */
66 #define SSIP_SW_BREAK 0
67 #define SSIP_BOOTINFO_REQ 1
68 #define SSIP_BOOTINFO_RESP 2
69 #define SSIP_WAKETEST_RESULT 3
70 #define SSIP_START_TRANS 4
71 #define SSIP_READY 5
72 /* Payloads */
73 #define SSIP_DATA_VERSION(data) ((data) & 0xff)
74 #define SSIP_LOCAL_VERID 1
75 #define SSIP_WAKETEST_OK 0
76 #define SSIP_WAKETEST_FAILED 1
77 #define SSIP_PDU_LENGTH(data) (((data) >> 8) & 0xffff)
78 #define SSIP_MSG_ID(data) ((data) & 0xff)
79 /* Generic Command */
80 #define SSIP_CMD(cmd, payload) (((cmd) << 28) | ((payload) & 0xfffffff))
81 /* Commands for the control channel */
82 #define SSIP_BOOTINFO_REQ_CMD(ver) \
83 SSIP_CMD(SSIP_BOOTINFO_REQ, SSIP_DATA_VERSION(ver))
84 #define SSIP_BOOTINFO_RESP_CMD(ver) \
85 SSIP_CMD(SSIP_BOOTINFO_RESP, SSIP_DATA_VERSION(ver))
86 #define SSIP_START_TRANS_CMD(pdulen, id) \
87 SSIP_CMD(SSIP_START_TRANS, (((pdulen) << 8) | SSIP_MSG_ID(id)))
88 #define SSIP_READY_CMD SSIP_CMD(SSIP_READY, 0)
89 #define SSIP_SWBREAK_CMD SSIP_CMD(SSIP_SW_BREAK, 0)
90
91 #define SSIP_WAKETEST_FLAG 0
92
93 /* Main state machine states */
94 enum {
95 INIT,
96 HANDSHAKE,
97 ACTIVE,
98 };
99
100 /* Send state machine states */
101 enum {
102 SEND_IDLE,
103 WAIT4READY,
104 SEND_READY,
105 SENDING,
106 SENDING_SWBREAK,
107 };
108
109 /* Receive state machine states */
110 enum {
111 RECV_IDLE,
112 RECV_READY,
113 RECEIVING,
114 };
115
116 /**
117 * struct ssi_protocol - SSI protocol (McSAAB) data
118 * @main_state: Main state machine
119 * @send_state: TX state machine
120 * @recv_state: RX state machine
121 * @flags: Flags, currently only used to follow wake line test
122 * @rxid: RX data id
123 * @txid: TX data id
124 * @txqueue_len: TX queue length
125 * @tx_wd: TX watchdog
126 * @rx_wd: RX watchdog
127 * @keep_alive: Workaround for SSI HW bug
128 * @lock: To serialize access to this struct
129 * @netdev: Phonet network device
130 * @txqueue: TX data queue
131 * @cmdqueue: Queue of free commands
132 * @cl: HSI client own reference
133 * @link: Link for ssip_list
134 * @tx_usecount: Refcount to keep track the slaves that use the wake line
135 * @channel_id_cmd: HSI channel id for command stream
136 * @channel_id_data: HSI channel id for data stream
137 */
138 struct ssi_protocol {
139 unsigned int main_state;
140 unsigned int send_state;
141 unsigned int recv_state;
142 unsigned long flags;
143 u8 rxid;
144 u8 txid;
145 unsigned int txqueue_len;
146 struct timer_list tx_wd;
147 struct timer_list rx_wd;
148 struct timer_list keep_alive; /* wake-up workaround */
149 spinlock_t lock;
150 struct net_device *netdev;
151 struct list_head txqueue;
152 struct list_head cmdqueue;
153 struct work_struct work;
154 struct hsi_client *cl;
155 struct list_head link;
156 atomic_t tx_usecnt;
157 int channel_id_cmd;
158 int channel_id_data;
159 };
160
161 /* List of ssi protocol instances */
162 static LIST_HEAD(ssip_list);
163
164 static void ssip_rxcmd_complete(struct hsi_msg *msg);
165
166 static inline void ssip_set_cmd(struct hsi_msg *msg, u32 cmd)
167 {
168 u32 *data;
169
170 data = sg_virt(msg->sgt.sgl);
171 *data = cmd;
172 }
173
174 static inline u32 ssip_get_cmd(struct hsi_msg *msg)
175 {
176 u32 *data;
177
178 data = sg_virt(msg->sgt.sgl);
179
180 return *data;
181 }
182
183 static void ssip_skb_to_msg(struct sk_buff *skb, struct hsi_msg *msg)
184 {
185 skb_frag_t *frag;
186 struct scatterlist *sg;
187 int i;
188
189 BUG_ON(msg->sgt.nents != (unsigned int)(skb_shinfo(skb)->nr_frags + 1));
190
191 sg = msg->sgt.sgl;
192 sg_set_buf(sg, skb->data, skb_headlen(skb));
193 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
194 sg = sg_next(sg);
195 BUG_ON(!sg);
196 frag = &skb_shinfo(skb)->frags[i];
197 sg_set_page(sg, frag->page.p, frag->size, frag->page_offset);
198 }
199 }
200
201 static void ssip_free_data(struct hsi_msg *msg)
202 {
203 struct sk_buff *skb;
204
205 skb = msg->context;
206 pr_debug("free data: msg %p context %p skb %p\n", msg, msg->context,
207 skb);
208 msg->destructor = NULL;
209 dev_kfree_skb(skb);
210 hsi_free_msg(msg);
211 }
212
213 static struct hsi_msg *ssip_alloc_data(struct ssi_protocol *ssi,
214 struct sk_buff *skb, gfp_t flags)
215 {
216 struct hsi_msg *msg;
217
218 msg = hsi_alloc_msg(skb_shinfo(skb)->nr_frags + 1, flags);
219 if (!msg)
220 return NULL;
221 ssip_skb_to_msg(skb, msg);
222 msg->destructor = ssip_free_data;
223 msg->channel = ssi->channel_id_data;
224 msg->context = skb;
225
226 return msg;
227 }
228
229 static inline void ssip_release_cmd(struct hsi_msg *msg)
230 {
231 struct ssi_protocol *ssi = hsi_client_drvdata(msg->cl);
232
233 dev_dbg(&msg->cl->device, "Release cmd 0x%08x\n", ssip_get_cmd(msg));
234 spin_lock_bh(&ssi->lock);
235 list_add_tail(&msg->link, &ssi->cmdqueue);
236 spin_unlock_bh(&ssi->lock);
237 }
238
239 static struct hsi_msg *ssip_claim_cmd(struct ssi_protocol *ssi)
240 {
241 struct hsi_msg *msg;
242
243 BUG_ON(list_empty(&ssi->cmdqueue));
244
245 spin_lock_bh(&ssi->lock);
246 msg = list_first_entry(&ssi->cmdqueue, struct hsi_msg, link);
247 list_del(&msg->link);
248 spin_unlock_bh(&ssi->lock);
249 msg->destructor = ssip_release_cmd;
250
251 return msg;
252 }
253
254 static void ssip_free_cmds(struct ssi_protocol *ssi)
255 {
256 struct hsi_msg *msg, *tmp;
257
258 list_for_each_entry_safe(msg, tmp, &ssi->cmdqueue, link) {
259 list_del(&msg->link);
260 msg->destructor = NULL;
261 kfree(sg_virt(msg->sgt.sgl));
262 hsi_free_msg(msg);
263 }
264 }
265
266 static int ssip_alloc_cmds(struct ssi_protocol *ssi)
267 {
268 struct hsi_msg *msg;
269 u32 *buf;
270 unsigned int i;
271
272 for (i = 0; i < SSIP_MAX_CMDS; i++) {
273 msg = hsi_alloc_msg(1, GFP_KERNEL);
274 if (!msg)
275 goto out;
276 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
277 if (!buf) {
278 hsi_free_msg(msg);
279 goto out;
280 }
281 sg_init_one(msg->sgt.sgl, buf, sizeof(*buf));
282 msg->channel = ssi->channel_id_cmd;
283 list_add_tail(&msg->link, &ssi->cmdqueue);
284 }
285
286 return 0;
287 out:
288 ssip_free_cmds(ssi);
289
290 return -ENOMEM;
291 }
292
293 static void ssip_set_rxstate(struct ssi_protocol *ssi, unsigned int state)
294 {
295 ssi->recv_state = state;
296 switch (state) {
297 case RECV_IDLE:
298 del_timer(&ssi->rx_wd);
299 if (ssi->send_state == SEND_IDLE)
300 del_timer(&ssi->keep_alive);
301 break;
302 case RECV_READY:
303 /* CMT speech workaround */
304 if (atomic_read(&ssi->tx_usecnt))
305 break;
306 /* Otherwise fall through */
307 case RECEIVING:
308 mod_timer(&ssi->keep_alive, jiffies +
309 msecs_to_jiffies(SSIP_KATOUT));
310 mod_timer(&ssi->rx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
311 break;
312 default:
313 break;
314 }
315 }
316
317 static void ssip_set_txstate(struct ssi_protocol *ssi, unsigned int state)
318 {
319 ssi->send_state = state;
320 switch (state) {
321 case SEND_IDLE:
322 case SEND_READY:
323 del_timer(&ssi->tx_wd);
324 if (ssi->recv_state == RECV_IDLE)
325 del_timer(&ssi->keep_alive);
326 break;
327 case WAIT4READY:
328 case SENDING:
329 case SENDING_SWBREAK:
330 mod_timer(&ssi->keep_alive,
331 jiffies + msecs_to_jiffies(SSIP_KATOUT));
332 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
333 break;
334 default:
335 break;
336 }
337 }
338
339 struct hsi_client *ssip_slave_get_master(struct hsi_client *slave)
340 {
341 struct hsi_client *master = ERR_PTR(-ENODEV);
342 struct ssi_protocol *ssi;
343
344 list_for_each_entry(ssi, &ssip_list, link)
345 if (slave->device.parent == ssi->cl->device.parent) {
346 master = ssi->cl;
347 break;
348 }
349
350 return master;
351 }
352 EXPORT_SYMBOL_GPL(ssip_slave_get_master);
353
354 int ssip_slave_start_tx(struct hsi_client *master)
355 {
356 struct ssi_protocol *ssi = hsi_client_drvdata(master);
357
358 dev_dbg(&master->device, "start TX %d\n", atomic_read(&ssi->tx_usecnt));
359 spin_lock_bh(&ssi->lock);
360 if (ssi->send_state == SEND_IDLE) {
361 ssip_set_txstate(ssi, WAIT4READY);
362 hsi_start_tx(master);
363 }
364 spin_unlock_bh(&ssi->lock);
365 atomic_inc(&ssi->tx_usecnt);
366
367 return 0;
368 }
369 EXPORT_SYMBOL_GPL(ssip_slave_start_tx);
370
371 int ssip_slave_stop_tx(struct hsi_client *master)
372 {
373 struct ssi_protocol *ssi = hsi_client_drvdata(master);
374
375 WARN_ON_ONCE(atomic_read(&ssi->tx_usecnt) == 0);
376
377 if (atomic_dec_and_test(&ssi->tx_usecnt)) {
378 spin_lock_bh(&ssi->lock);
379 if ((ssi->send_state == SEND_READY) ||
380 (ssi->send_state == WAIT4READY)) {
381 ssip_set_txstate(ssi, SEND_IDLE);
382 hsi_stop_tx(master);
383 }
384 spin_unlock_bh(&ssi->lock);
385 }
386 dev_dbg(&master->device, "stop TX %d\n", atomic_read(&ssi->tx_usecnt));
387
388 return 0;
389 }
390 EXPORT_SYMBOL_GPL(ssip_slave_stop_tx);
391
392 int ssip_slave_running(struct hsi_client *master)
393 {
394 struct ssi_protocol *ssi = hsi_client_drvdata(master);
395 return netif_running(ssi->netdev);
396 }
397 EXPORT_SYMBOL_GPL(ssip_slave_running);
398
399 static void ssip_reset(struct hsi_client *cl)
400 {
401 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
402 struct list_head *head, *tmp;
403 struct hsi_msg *msg;
404
405 if (netif_running(ssi->netdev))
406 netif_carrier_off(ssi->netdev);
407 hsi_flush(cl);
408 spin_lock_bh(&ssi->lock);
409 if (ssi->send_state != SEND_IDLE)
410 hsi_stop_tx(cl);
411 spin_unlock_bh(&ssi->lock);
412 if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
413 ssi_waketest(cl, 0); /* FIXME: To be removed */
414 spin_lock_bh(&ssi->lock);
415 del_timer(&ssi->rx_wd);
416 del_timer(&ssi->tx_wd);
417 del_timer(&ssi->keep_alive);
418 ssi->main_state = 0;
419 ssi->send_state = 0;
420 ssi->recv_state = 0;
421 ssi->flags = 0;
422 ssi->rxid = 0;
423 ssi->txid = 0;
424 list_for_each_safe(head, tmp, &ssi->txqueue) {
425 msg = list_entry(head, struct hsi_msg, link);
426 dev_dbg(&cl->device, "Pending TX data\n");
427 list_del(head);
428 ssip_free_data(msg);
429 }
430 ssi->txqueue_len = 0;
431 spin_unlock_bh(&ssi->lock);
432 }
433
434 static void ssip_dump_state(struct hsi_client *cl)
435 {
436 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
437 struct hsi_msg *msg;
438
439 spin_lock_bh(&ssi->lock);
440 dev_err(&cl->device, "Main state: %d\n", ssi->main_state);
441 dev_err(&cl->device, "Recv state: %d\n", ssi->recv_state);
442 dev_err(&cl->device, "Send state: %d\n", ssi->send_state);
443 dev_err(&cl->device, "CMT %s\n", (ssi->main_state == ACTIVE) ?
444 "Online" : "Offline");
445 dev_err(&cl->device, "Wake test %d\n",
446 test_bit(SSIP_WAKETEST_FLAG, &ssi->flags));
447 dev_err(&cl->device, "Data RX id: %d\n", ssi->rxid);
448 dev_err(&cl->device, "Data TX id: %d\n", ssi->txid);
449
450 list_for_each_entry(msg, &ssi->txqueue, link)
451 dev_err(&cl->device, "pending TX data (%p)\n", msg);
452 spin_unlock_bh(&ssi->lock);
453 }
454
455 static void ssip_error(struct hsi_client *cl)
456 {
457 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
458 struct hsi_msg *msg;
459
460 ssip_dump_state(cl);
461 ssip_reset(cl);
462 msg = ssip_claim_cmd(ssi);
463 msg->complete = ssip_rxcmd_complete;
464 hsi_async_read(cl, msg);
465 }
466
467 static void ssip_keep_alive(struct timer_list *t)
468 {
469 struct ssi_protocol *ssi = from_timer(ssi, t, keep_alive);
470 struct hsi_client *cl = ssi->cl;
471
472 dev_dbg(&cl->device, "Keep alive kick in: m(%d) r(%d) s(%d)\n",
473 ssi->main_state, ssi->recv_state, ssi->send_state);
474
475 spin_lock(&ssi->lock);
476 if (ssi->recv_state == RECV_IDLE)
477 switch (ssi->send_state) {
478 case SEND_READY:
479 if (atomic_read(&ssi->tx_usecnt) == 0)
480 break;
481 /*
482 * Fall through. Workaround for cmt-speech
483 * in that case we relay on audio timers.
484 */
485 case SEND_IDLE:
486 spin_unlock(&ssi->lock);
487 return;
488 }
489 mod_timer(&ssi->keep_alive, jiffies + msecs_to_jiffies(SSIP_KATOUT));
490 spin_unlock(&ssi->lock);
491 }
492
493 static void ssip_rx_wd(struct timer_list *t)
494 {
495 struct ssi_protocol *ssi = from_timer(ssi, t, rx_wd);
496 struct hsi_client *cl = ssi->cl;
497
498 dev_err(&cl->device, "Watchdog trigerred\n");
499 ssip_error(cl);
500 }
501
502 static void ssip_tx_wd(struct timer_list *t)
503 {
504 struct ssi_protocol *ssi = from_timer(ssi, t, tx_wd);
505 struct hsi_client *cl = ssi->cl;
506
507 dev_err(&cl->device, "Watchdog trigerred\n");
508 ssip_error(cl);
509 }
510
511 static void ssip_send_bootinfo_req_cmd(struct hsi_client *cl)
512 {
513 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
514 struct hsi_msg *msg;
515
516 dev_dbg(&cl->device, "Issuing BOOT INFO REQ command\n");
517 msg = ssip_claim_cmd(ssi);
518 ssip_set_cmd(msg, SSIP_BOOTINFO_REQ_CMD(SSIP_LOCAL_VERID));
519 msg->complete = ssip_release_cmd;
520 hsi_async_write(cl, msg);
521 dev_dbg(&cl->device, "Issuing RX command\n");
522 msg = ssip_claim_cmd(ssi);
523 msg->complete = ssip_rxcmd_complete;
524 hsi_async_read(cl, msg);
525 }
526
527 static void ssip_start_rx(struct hsi_client *cl)
528 {
529 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
530 struct hsi_msg *msg;
531
532 dev_dbg(&cl->device, "RX start M(%d) R(%d)\n", ssi->main_state,
533 ssi->recv_state);
534 spin_lock_bh(&ssi->lock);
535 /*
536 * We can have two UP events in a row due to a short low
537 * high transition. Therefore we need to ignore the sencond UP event.
538 */
539 if ((ssi->main_state != ACTIVE) || (ssi->recv_state == RECV_READY)) {
540 spin_unlock_bh(&ssi->lock);
541 return;
542 }
543 ssip_set_rxstate(ssi, RECV_READY);
544 spin_unlock_bh(&ssi->lock);
545
546 msg = ssip_claim_cmd(ssi);
547 ssip_set_cmd(msg, SSIP_READY_CMD);
548 msg->complete = ssip_release_cmd;
549 dev_dbg(&cl->device, "Send READY\n");
550 hsi_async_write(cl, msg);
551 }
552
553 static void ssip_stop_rx(struct hsi_client *cl)
554 {
555 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
556
557 dev_dbg(&cl->device, "RX stop M(%d)\n", ssi->main_state);
558 spin_lock_bh(&ssi->lock);
559 if (likely(ssi->main_state == ACTIVE))
560 ssip_set_rxstate(ssi, RECV_IDLE);
561 spin_unlock_bh(&ssi->lock);
562 }
563
564 static void ssip_free_strans(struct hsi_msg *msg)
565 {
566 ssip_free_data(msg->context);
567 ssip_release_cmd(msg);
568 }
569
570 static void ssip_strans_complete(struct hsi_msg *msg)
571 {
572 struct hsi_client *cl = msg->cl;
573 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
574 struct hsi_msg *data;
575
576 data = msg->context;
577 ssip_release_cmd(msg);
578 spin_lock_bh(&ssi->lock);
579 ssip_set_txstate(ssi, SENDING);
580 spin_unlock_bh(&ssi->lock);
581 hsi_async_write(cl, data);
582 }
583
584 static int ssip_xmit(struct hsi_client *cl)
585 {
586 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
587 struct hsi_msg *msg, *dmsg;
588 struct sk_buff *skb;
589
590 spin_lock_bh(&ssi->lock);
591 if (list_empty(&ssi->txqueue)) {
592 spin_unlock_bh(&ssi->lock);
593 return 0;
594 }
595 dmsg = list_first_entry(&ssi->txqueue, struct hsi_msg, link);
596 list_del(&dmsg->link);
597 ssi->txqueue_len--;
598 spin_unlock_bh(&ssi->lock);
599
600 msg = ssip_claim_cmd(ssi);
601 skb = dmsg->context;
602 msg->context = dmsg;
603 msg->complete = ssip_strans_complete;
604 msg->destructor = ssip_free_strans;
605
606 spin_lock_bh(&ssi->lock);
607 ssip_set_cmd(msg, SSIP_START_TRANS_CMD(SSIP_BYTES_TO_FRAMES(skb->len),
608 ssi->txid));
609 ssi->txid++;
610 ssip_set_txstate(ssi, SENDING);
611 spin_unlock_bh(&ssi->lock);
612
613 dev_dbg(&cl->device, "Send STRANS (%d frames)\n",
614 SSIP_BYTES_TO_FRAMES(skb->len));
615
616 return hsi_async_write(cl, msg);
617 }
618
619 /* In soft IRQ context */
620 static void ssip_pn_rx(struct sk_buff *skb)
621 {
622 struct net_device *dev = skb->dev;
623
624 if (unlikely(!netif_running(dev))) {
625 dev_dbg(&dev->dev, "Drop RX packet\n");
626 dev->stats.rx_dropped++;
627 dev_kfree_skb(skb);
628 return;
629 }
630 if (unlikely(!pskb_may_pull(skb, SSIP_MIN_PN_HDR))) {
631 dev_dbg(&dev->dev, "Error drop RX packet\n");
632 dev->stats.rx_errors++;
633 dev->stats.rx_length_errors++;
634 dev_kfree_skb(skb);
635 return;
636 }
637 dev->stats.rx_packets++;
638 dev->stats.rx_bytes += skb->len;
639
640 /* length field is exchanged in network byte order */
641 ((u16 *)skb->data)[2] = ntohs(((u16 *)skb->data)[2]);
642 dev_dbg(&dev->dev, "RX length fixed (%04x -> %u)\n",
643 ((u16 *)skb->data)[2], ntohs(((u16 *)skb->data)[2]));
644
645 skb->protocol = htons(ETH_P_PHONET);
646 skb_reset_mac_header(skb);
647 __skb_pull(skb, 1);
648 netif_rx(skb);
649 }
650
651 static void ssip_rx_data_complete(struct hsi_msg *msg)
652 {
653 struct hsi_client *cl = msg->cl;
654 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
655 struct sk_buff *skb;
656
657 if (msg->status == HSI_STATUS_ERROR) {
658 dev_err(&cl->device, "RX data error\n");
659 ssip_free_data(msg);
660 ssip_error(cl);
661 return;
662 }
663 del_timer(&ssi->rx_wd); /* FIXME: Revisit */
664 skb = msg->context;
665 ssip_pn_rx(skb);
666 hsi_free_msg(msg);
667 }
668
669 static void ssip_rx_bootinforeq(struct hsi_client *cl, u32 cmd)
670 {
671 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
672 struct hsi_msg *msg;
673
674 /* Workaroud: Ignore CMT Loader message leftover */
675 if (cmd == SSIP_CMT_LOADER_SYNC)
676 return;
677
678 switch (ssi->main_state) {
679 case ACTIVE:
680 dev_err(&cl->device, "Boot info req on active state\n");
681 ssip_error(cl);
682 /* Fall through */
683 case INIT:
684 case HANDSHAKE:
685 spin_lock_bh(&ssi->lock);
686 ssi->main_state = HANDSHAKE;
687 spin_unlock_bh(&ssi->lock);
688
689 if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
690 ssi_waketest(cl, 1); /* FIXME: To be removed */
691
692 spin_lock_bh(&ssi->lock);
693 /* Start boot handshake watchdog */
694 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
695 spin_unlock_bh(&ssi->lock);
696 dev_dbg(&cl->device, "Send BOOTINFO_RESP\n");
697 if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
698 dev_warn(&cl->device, "boot info req verid mismatch\n");
699 msg = ssip_claim_cmd(ssi);
700 ssip_set_cmd(msg, SSIP_BOOTINFO_RESP_CMD(SSIP_LOCAL_VERID));
701 msg->complete = ssip_release_cmd;
702 hsi_async_write(cl, msg);
703 break;
704 default:
705 dev_dbg(&cl->device, "Wrong state M(%d)\n", ssi->main_state);
706 break;
707 }
708 }
709
710 static void ssip_rx_bootinforesp(struct hsi_client *cl, u32 cmd)
711 {
712 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
713
714 if (SSIP_DATA_VERSION(cmd) != SSIP_LOCAL_VERID)
715 dev_warn(&cl->device, "boot info resp verid mismatch\n");
716
717 spin_lock_bh(&ssi->lock);
718 if (ssi->main_state != ACTIVE)
719 /* Use tx_wd as a boot watchdog in non ACTIVE state */
720 mod_timer(&ssi->tx_wd, jiffies + msecs_to_jiffies(SSIP_WDTOUT));
721 else
722 dev_dbg(&cl->device, "boot info resp ignored M(%d)\n",
723 ssi->main_state);
724 spin_unlock_bh(&ssi->lock);
725 }
726
727 static void ssip_rx_waketest(struct hsi_client *cl, u32 cmd)
728 {
729 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
730 unsigned int wkres = SSIP_PAYLOAD(cmd);
731
732 spin_lock_bh(&ssi->lock);
733 if (ssi->main_state != HANDSHAKE) {
734 dev_dbg(&cl->device, "wake lines test ignored M(%d)\n",
735 ssi->main_state);
736 spin_unlock_bh(&ssi->lock);
737 return;
738 }
739 spin_unlock_bh(&ssi->lock);
740
741 if (test_and_clear_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
742 ssi_waketest(cl, 0); /* FIXME: To be removed */
743
744 spin_lock_bh(&ssi->lock);
745 ssi->main_state = ACTIVE;
746 del_timer(&ssi->tx_wd); /* Stop boot handshake timer */
747 spin_unlock_bh(&ssi->lock);
748
749 dev_notice(&cl->device, "WAKELINES TEST %s\n",
750 wkres & SSIP_WAKETEST_FAILED ? "FAILED" : "OK");
751 if (wkres & SSIP_WAKETEST_FAILED) {
752 ssip_error(cl);
753 return;
754 }
755 dev_dbg(&cl->device, "CMT is ONLINE\n");
756 netif_wake_queue(ssi->netdev);
757 netif_carrier_on(ssi->netdev);
758 }
759
760 static void ssip_rx_ready(struct hsi_client *cl)
761 {
762 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
763
764 spin_lock_bh(&ssi->lock);
765 if (unlikely(ssi->main_state != ACTIVE)) {
766 dev_dbg(&cl->device, "READY on wrong state: S(%d) M(%d)\n",
767 ssi->send_state, ssi->main_state);
768 spin_unlock_bh(&ssi->lock);
769 return;
770 }
771 if (ssi->send_state != WAIT4READY) {
772 dev_dbg(&cl->device, "Ignore spurious READY command\n");
773 spin_unlock_bh(&ssi->lock);
774 return;
775 }
776 ssip_set_txstate(ssi, SEND_READY);
777 spin_unlock_bh(&ssi->lock);
778 ssip_xmit(cl);
779 }
780
781 static void ssip_rx_strans(struct hsi_client *cl, u32 cmd)
782 {
783 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
784 struct sk_buff *skb;
785 struct hsi_msg *msg;
786 int len = SSIP_PDU_LENGTH(cmd);
787
788 dev_dbg(&cl->device, "RX strans: %d frames\n", len);
789 spin_lock_bh(&ssi->lock);
790 if (unlikely(ssi->main_state != ACTIVE)) {
791 dev_err(&cl->device, "START TRANS wrong state: S(%d) M(%d)\n",
792 ssi->send_state, ssi->main_state);
793 spin_unlock_bh(&ssi->lock);
794 return;
795 }
796 ssip_set_rxstate(ssi, RECEIVING);
797 if (unlikely(SSIP_MSG_ID(cmd) != ssi->rxid)) {
798 dev_err(&cl->device, "START TRANS id %d expected %d\n",
799 SSIP_MSG_ID(cmd), ssi->rxid);
800 spin_unlock_bh(&ssi->lock);
801 goto out1;
802 }
803 ssi->rxid++;
804 spin_unlock_bh(&ssi->lock);
805 skb = netdev_alloc_skb(ssi->netdev, len * 4);
806 if (unlikely(!skb)) {
807 dev_err(&cl->device, "No memory for rx skb\n");
808 goto out1;
809 }
810 skb->dev = ssi->netdev;
811 skb_put(skb, len * 4);
812 msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
813 if (unlikely(!msg)) {
814 dev_err(&cl->device, "No memory for RX data msg\n");
815 goto out2;
816 }
817 msg->complete = ssip_rx_data_complete;
818 hsi_async_read(cl, msg);
819
820 return;
821 out2:
822 dev_kfree_skb(skb);
823 out1:
824 ssip_error(cl);
825 }
826
827 static void ssip_rxcmd_complete(struct hsi_msg *msg)
828 {
829 struct hsi_client *cl = msg->cl;
830 u32 cmd = ssip_get_cmd(msg);
831 unsigned int cmdid = SSIP_COMMAND(cmd);
832
833 if (msg->status == HSI_STATUS_ERROR) {
834 dev_err(&cl->device, "RX error detected\n");
835 ssip_release_cmd(msg);
836 ssip_error(cl);
837 return;
838 }
839 hsi_async_read(cl, msg);
840 dev_dbg(&cl->device, "RX cmd: 0x%08x\n", cmd);
841 switch (cmdid) {
842 case SSIP_SW_BREAK:
843 /* Ignored */
844 break;
845 case SSIP_BOOTINFO_REQ:
846 ssip_rx_bootinforeq(cl, cmd);
847 break;
848 case SSIP_BOOTINFO_RESP:
849 ssip_rx_bootinforesp(cl, cmd);
850 break;
851 case SSIP_WAKETEST_RESULT:
852 ssip_rx_waketest(cl, cmd);
853 break;
854 case SSIP_START_TRANS:
855 ssip_rx_strans(cl, cmd);
856 break;
857 case SSIP_READY:
858 ssip_rx_ready(cl);
859 break;
860 default:
861 dev_warn(&cl->device, "command 0x%08x not supported\n", cmd);
862 break;
863 }
864 }
865
866 static void ssip_swbreak_complete(struct hsi_msg *msg)
867 {
868 struct hsi_client *cl = msg->cl;
869 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
870
871 ssip_release_cmd(msg);
872 spin_lock_bh(&ssi->lock);
873 if (list_empty(&ssi->txqueue)) {
874 if (atomic_read(&ssi->tx_usecnt)) {
875 ssip_set_txstate(ssi, SEND_READY);
876 } else {
877 ssip_set_txstate(ssi, SEND_IDLE);
878 hsi_stop_tx(cl);
879 }
880 spin_unlock_bh(&ssi->lock);
881 } else {
882 spin_unlock_bh(&ssi->lock);
883 ssip_xmit(cl);
884 }
885 netif_wake_queue(ssi->netdev);
886 }
887
888 static void ssip_tx_data_complete(struct hsi_msg *msg)
889 {
890 struct hsi_client *cl = msg->cl;
891 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
892 struct hsi_msg *cmsg;
893
894 if (msg->status == HSI_STATUS_ERROR) {
895 dev_err(&cl->device, "TX data error\n");
896 ssip_error(cl);
897 goto out;
898 }
899 spin_lock_bh(&ssi->lock);
900 if (list_empty(&ssi->txqueue)) {
901 ssip_set_txstate(ssi, SENDING_SWBREAK);
902 spin_unlock_bh(&ssi->lock);
903 cmsg = ssip_claim_cmd(ssi);
904 ssip_set_cmd(cmsg, SSIP_SWBREAK_CMD);
905 cmsg->complete = ssip_swbreak_complete;
906 dev_dbg(&cl->device, "Send SWBREAK\n");
907 hsi_async_write(cl, cmsg);
908 } else {
909 spin_unlock_bh(&ssi->lock);
910 ssip_xmit(cl);
911 }
912 out:
913 ssip_free_data(msg);
914 }
915
916 static void ssip_port_event(struct hsi_client *cl, unsigned long event)
917 {
918 switch (event) {
919 case HSI_EVENT_START_RX:
920 ssip_start_rx(cl);
921 break;
922 case HSI_EVENT_STOP_RX:
923 ssip_stop_rx(cl);
924 break;
925 default:
926 return;
927 }
928 }
929
930 static int ssip_pn_open(struct net_device *dev)
931 {
932 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
933 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
934 int err;
935
936 err = hsi_claim_port(cl, 1);
937 if (err < 0) {
938 dev_err(&cl->device, "SSI port already claimed\n");
939 return err;
940 }
941 err = hsi_register_port_event(cl, ssip_port_event);
942 if (err < 0) {
943 dev_err(&cl->device, "Register HSI port event failed (%d)\n",
944 err);
945 return err;
946 }
947 dev_dbg(&cl->device, "Configuring SSI port\n");
948 hsi_setup(cl);
949
950 if (!test_and_set_bit(SSIP_WAKETEST_FLAG, &ssi->flags))
951 ssi_waketest(cl, 1); /* FIXME: To be removed */
952
953 spin_lock_bh(&ssi->lock);
954 ssi->main_state = HANDSHAKE;
955 spin_unlock_bh(&ssi->lock);
956
957 ssip_send_bootinfo_req_cmd(cl);
958
959 return 0;
960 }
961
962 static int ssip_pn_stop(struct net_device *dev)
963 {
964 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
965
966 ssip_reset(cl);
967 hsi_unregister_port_event(cl);
968 hsi_release_port(cl);
969
970 return 0;
971 }
972
973 static void ssip_xmit_work(struct work_struct *work)
974 {
975 struct ssi_protocol *ssi =
976 container_of(work, struct ssi_protocol, work);
977 struct hsi_client *cl = ssi->cl;
978
979 ssip_xmit(cl);
980 }
981
982 static int ssip_pn_xmit(struct sk_buff *skb, struct net_device *dev)
983 {
984 struct hsi_client *cl = to_hsi_client(dev->dev.parent);
985 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
986 struct hsi_msg *msg;
987
988 if ((skb->protocol != htons(ETH_P_PHONET)) ||
989 (skb->len < SSIP_MIN_PN_HDR))
990 goto drop;
991 /* Pad to 32-bits - FIXME: Revisit*/
992 if ((skb->len & 3) && skb_pad(skb, 4 - (skb->len & 3)))
993 goto inc_dropped;
994
995 /*
996 * Modem sends Phonet messages over SSI with its own endianess...
997 * Assume that modem has the same endianess as we do.
998 */
999 if (skb_cow_head(skb, 0))
1000 goto drop;
1001
1002 /* length field is exchanged in network byte order */
1003 ((u16 *)skb->data)[2] = htons(((u16 *)skb->data)[2]);
1004
1005 msg = ssip_alloc_data(ssi, skb, GFP_ATOMIC);
1006 if (!msg) {
1007 dev_dbg(&cl->device, "Dropping tx data: No memory\n");
1008 goto drop;
1009 }
1010 msg->complete = ssip_tx_data_complete;
1011
1012 spin_lock_bh(&ssi->lock);
1013 if (unlikely(ssi->main_state != ACTIVE)) {
1014 spin_unlock_bh(&ssi->lock);
1015 dev_dbg(&cl->device, "Dropping tx data: CMT is OFFLINE\n");
1016 goto drop2;
1017 }
1018 list_add_tail(&msg->link, &ssi->txqueue);
1019 ssi->txqueue_len++;
1020 if (dev->tx_queue_len < ssi->txqueue_len) {
1021 dev_info(&cl->device, "TX queue full %d\n", ssi->txqueue_len);
1022 netif_stop_queue(dev);
1023 }
1024 if (ssi->send_state == SEND_IDLE) {
1025 ssip_set_txstate(ssi, WAIT4READY);
1026 spin_unlock_bh(&ssi->lock);
1027 dev_dbg(&cl->device, "Start TX qlen %d\n", ssi->txqueue_len);
1028 hsi_start_tx(cl);
1029 } else if (ssi->send_state == SEND_READY) {
1030 /* Needed for cmt-speech workaround */
1031 dev_dbg(&cl->device, "Start TX on SEND READY qlen %d\n",
1032 ssi->txqueue_len);
1033 spin_unlock_bh(&ssi->lock);
1034 schedule_work(&ssi->work);
1035 } else {
1036 spin_unlock_bh(&ssi->lock);
1037 }
1038 dev->stats.tx_packets++;
1039 dev->stats.tx_bytes += skb->len;
1040
1041 return 0;
1042 drop2:
1043 hsi_free_msg(msg);
1044 drop:
1045 dev_kfree_skb(skb);
1046 inc_dropped:
1047 dev->stats.tx_dropped++;
1048
1049 return 0;
1050 }
1051
1052 /* CMT reset event handler */
1053 void ssip_reset_event(struct hsi_client *master)
1054 {
1055 struct ssi_protocol *ssi = hsi_client_drvdata(master);
1056 dev_err(&ssi->cl->device, "CMT reset detected!\n");
1057 ssip_error(ssi->cl);
1058 }
1059 EXPORT_SYMBOL_GPL(ssip_reset_event);
1060
1061 static const struct net_device_ops ssip_pn_ops = {
1062 .ndo_open = ssip_pn_open,
1063 .ndo_stop = ssip_pn_stop,
1064 .ndo_start_xmit = ssip_pn_xmit,
1065 };
1066
1067 static void ssip_pn_setup(struct net_device *dev)
1068 {
1069 dev->features = 0;
1070 dev->netdev_ops = &ssip_pn_ops;
1071 dev->type = ARPHRD_PHONET;
1072 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1073 dev->mtu = SSIP_DEFAULT_MTU;
1074 dev->hard_header_len = 1;
1075 dev->dev_addr[0] = PN_MEDIA_SOS;
1076 dev->addr_len = 1;
1077 dev->tx_queue_len = SSIP_TXQUEUE_LEN;
1078
1079 dev->needs_free_netdev = true;
1080 dev->header_ops = &phonet_header_ops;
1081 }
1082
1083 static int ssi_protocol_probe(struct device *dev)
1084 {
1085 static const char ifname[] = "phonet%d";
1086 struct hsi_client *cl = to_hsi_client(dev);
1087 struct ssi_protocol *ssi;
1088 int err;
1089
1090 ssi = kzalloc(sizeof(*ssi), GFP_KERNEL);
1091 if (!ssi) {
1092 dev_err(dev, "No memory for ssi protocol\n");
1093 return -ENOMEM;
1094 }
1095
1096 spin_lock_init(&ssi->lock);
1097 timer_setup(&ssi->rx_wd, ssip_rx_wd, TIMER_DEFERRABLE);
1098 timer_setup(&ssi->tx_wd, ssip_tx_wd, TIMER_DEFERRABLE);
1099 timer_setup(&ssi->keep_alive, ssip_keep_alive, 0);
1100 INIT_LIST_HEAD(&ssi->txqueue);
1101 INIT_LIST_HEAD(&ssi->cmdqueue);
1102 atomic_set(&ssi->tx_usecnt, 0);
1103 hsi_client_set_drvdata(cl, ssi);
1104 ssi->cl = cl;
1105 INIT_WORK(&ssi->work, ssip_xmit_work);
1106
1107 ssi->channel_id_cmd = hsi_get_channel_id_by_name(cl, "mcsaab-control");
1108 if (ssi->channel_id_cmd < 0) {
1109 err = ssi->channel_id_cmd;
1110 dev_err(dev, "Could not get cmd channel (%d)\n", err);
1111 goto out;
1112 }
1113
1114 ssi->channel_id_data = hsi_get_channel_id_by_name(cl, "mcsaab-data");
1115 if (ssi->channel_id_data < 0) {
1116 err = ssi->channel_id_data;
1117 dev_err(dev, "Could not get data channel (%d)\n", err);
1118 goto out;
1119 }
1120
1121 err = ssip_alloc_cmds(ssi);
1122 if (err < 0) {
1123 dev_err(dev, "No memory for commands\n");
1124 goto out;
1125 }
1126
1127 ssi->netdev = alloc_netdev(0, ifname, NET_NAME_UNKNOWN, ssip_pn_setup);
1128 if (!ssi->netdev) {
1129 dev_err(dev, "No memory for netdev\n");
1130 err = -ENOMEM;
1131 goto out1;
1132 }
1133
1134 /* MTU range: 6 - 65535 */
1135 ssi->netdev->min_mtu = PHONET_MIN_MTU;
1136 ssi->netdev->max_mtu = SSIP_MAX_MTU;
1137
1138 SET_NETDEV_DEV(ssi->netdev, dev);
1139 netif_carrier_off(ssi->netdev);
1140 err = register_netdev(ssi->netdev);
1141 if (err < 0) {
1142 dev_err(dev, "Register netdev failed (%d)\n", err);
1143 goto out2;
1144 }
1145
1146 list_add(&ssi->link, &ssip_list);
1147
1148 dev_dbg(dev, "channel configuration: cmd=%d, data=%d\n",
1149 ssi->channel_id_cmd, ssi->channel_id_data);
1150
1151 return 0;
1152 out2:
1153 free_netdev(ssi->netdev);
1154 out1:
1155 ssip_free_cmds(ssi);
1156 out:
1157 kfree(ssi);
1158
1159 return err;
1160 }
1161
1162 static int ssi_protocol_remove(struct device *dev)
1163 {
1164 struct hsi_client *cl = to_hsi_client(dev);
1165 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
1166
1167 list_del(&ssi->link);
1168 unregister_netdev(ssi->netdev);
1169 ssip_free_cmds(ssi);
1170 hsi_client_set_drvdata(cl, NULL);
1171 kfree(ssi);
1172
1173 return 0;
1174 }
1175
1176 static struct hsi_client_driver ssip_driver = {
1177 .driver = {
1178 .name = "ssi-protocol",
1179 .owner = THIS_MODULE,
1180 .probe = ssi_protocol_probe,
1181 .remove = ssi_protocol_remove,
1182 },
1183 };
1184
1185 static int __init ssip_init(void)
1186 {
1187 pr_info("SSI protocol aka McSAAB added\n");
1188
1189 return hsi_register_client_driver(&ssip_driver);
1190 }
1191 module_init(ssip_init);
1192
1193 static void __exit ssip_exit(void)
1194 {
1195 hsi_unregister_client_driver(&ssip_driver);
1196 pr_info("SSI protocol driver removed\n");
1197 }
1198 module_exit(ssip_exit);
1199
1200 MODULE_ALIAS("hsi:ssi-protocol");
1201 MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
1202 MODULE_AUTHOR("Remi Denis-Courmont <remi.denis-courmont@nokia.com>");
1203 MODULE_DESCRIPTION("SSI protocol improved aka McSAAB");
1204 MODULE_LICENSE("GPL");
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