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 */
79enum {
80 INIT,
81 HANDSHAKE,
82 ACTIVE,
83};
84
85/* Send state machine states */
86enum {
87 SEND_IDLE,
88 WAIT4READY,
89 SEND_READY,
90 SENDING,
91 SENDING_SWBREAK,
92};
93
94/* Receive state machine states */
95enum {
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 * @work: &struct work_struct for scheduled work
118 * @cl: HSI client own reference
119 * @link: Link for ssip_list
120 * @tx_usecnt: Refcount to keep track the slaves that use the wake line
121 * @channel_id_cmd: HSI channel id for command stream
122 * @channel_id_data: HSI channel id for data stream
123 */
124struct ssi_protocol {
125 unsigned int main_state;
126 unsigned int send_state;
127 unsigned int recv_state;
128 unsigned long flags;
129 u8 rxid;
130 u8 txid;
131 unsigned int txqueue_len;
132 struct timer_list tx_wd;
133 struct timer_list rx_wd;
134 struct timer_list keep_alive; /* wake-up workaround */
135 spinlock_t lock;
136 struct net_device *netdev;
137 struct list_head txqueue;
138 struct list_head cmdqueue;
139 struct work_struct work;
140 struct hsi_client *cl;
141 struct list_head link;
142 atomic_t tx_usecnt;
143 int channel_id_cmd;
144 int channel_id_data;
145};
146
147/* List of ssi protocol instances */
148static LIST_HEAD(ssip_list);
149
150static void ssip_rxcmd_complete(struct hsi_msg *msg);
151
152static inline void ssip_set_cmd(struct hsi_msg *msg, u32 cmd)
153{
154 u32 *data;
155
156 data = sg_virt(sg: msg->sgt.sgl);
157 *data = cmd;
158}
159
160static inline u32 ssip_get_cmd(struct hsi_msg *msg)
161{
162 u32 *data;
163
164 data = sg_virt(sg: msg->sgt.sgl);
165
166 return *data;
167}
168
169static void ssip_skb_to_msg(struct sk_buff *skb, struct hsi_msg *msg)
170{
171 skb_frag_t *frag;
172 struct scatterlist *sg;
173 int i;
174
175 BUG_ON(msg->sgt.nents != (unsigned int)(skb_shinfo(skb)->nr_frags + 1));
176
177 sg = msg->sgt.sgl;
178 sg_set_buf(sg, buf: skb->data, buflen: skb_headlen(skb));
179 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
180 sg = sg_next(sg);
181 BUG_ON(!sg);
182 frag = &skb_shinfo(skb)->frags[i];
183 sg_set_page(sg, page: skb_frag_page(frag), len: skb_frag_size(frag),
184 offset: skb_frag_off(frag));
185 }
186}
187
188static void ssip_free_data(struct hsi_msg *msg)
189{
190 struct sk_buff *skb;
191
192 skb = msg->context;
193 pr_debug("free data: msg %p context %p skb %p\n", msg, msg->context,
194 skb);
195 msg->destructor = NULL;
196 dev_kfree_skb(skb);
197 hsi_free_msg(msg);
198}
199
200static struct hsi_msg *ssip_alloc_data(struct ssi_protocol *ssi,
201 struct sk_buff *skb, gfp_t flags)
202{
203 struct hsi_msg *msg;
204
205 msg = hsi_alloc_msg(skb_shinfo(skb)->nr_frags + 1, flags);
206 if (!msg)
207 return NULL;
208 ssip_skb_to_msg(skb, msg);
209 msg->destructor = ssip_free_data;
210 msg->channel = ssi->channel_id_data;
211 msg->context = skb;
212
213 return msg;
214}
215
216static inline void ssip_release_cmd(struct hsi_msg *msg)
217{
218 struct ssi_protocol *ssi = hsi_client_drvdata(cl: msg->cl);
219
220 dev_dbg(&msg->cl->device, "Release cmd 0x%08x\n", ssip_get_cmd(msg));
221 spin_lock_bh(lock: &ssi->lock);
222 list_add_tail(new: &msg->link, head: &ssi->cmdqueue);
223 spin_unlock_bh(lock: &ssi->lock);
224}
225
226static struct hsi_msg *ssip_claim_cmd(struct ssi_protocol *ssi)
227{
228 struct hsi_msg *msg;
229
230 BUG_ON(list_empty(&ssi->cmdqueue));
231
232 spin_lock_bh(lock: &ssi->lock);
233 msg = list_first_entry(&ssi->cmdqueue, struct hsi_msg, link);
234 list_del(entry: &msg->link);
235 spin_unlock_bh(lock: &ssi->lock);
236 msg->destructor = ssip_release_cmd;
237
238 return msg;
239}
240
241static void ssip_free_cmds(struct ssi_protocol *ssi)
242{
243 struct hsi_msg *msg, *tmp;
244
245 list_for_each_entry_safe(msg, tmp, &ssi->cmdqueue, link) {
246 list_del(entry: &msg->link);
247 msg->destructor = NULL;
248 kfree(objp: sg_virt(sg: msg->sgt.sgl));
249 hsi_free_msg(msg);
250 }
251}
252
253static int ssip_alloc_cmds(struct ssi_protocol *ssi)
254{
255 struct hsi_msg *msg;
256 u32 *buf;
257 unsigned int i;
258
259 for (i = 0; i < SSIP_MAX_CMDS; i++) {
260 msg = hsi_alloc_msg(n_frag: 1, GFP_KERNEL);
261 if (!msg)
262 goto out;
263 buf = kmalloc(size: sizeof(*buf), GFP_KERNEL);
264 if (!buf) {
265 hsi_free_msg(msg);
266 goto out;
267 }
268 sg_init_one(msg->sgt.sgl, buf, sizeof(*buf));
269 msg->channel = ssi->channel_id_cmd;
270 list_add_tail(new: &msg->link, head: &ssi->cmdqueue);
271 }
272
273 return 0;
274out:
275 ssip_free_cmds(ssi);
276
277 return -ENOMEM;
278}
279
280static void ssip_set_rxstate(struct ssi_protocol *ssi, unsigned int state)
281{
282 ssi->recv_state = state;
283 switch (state) {
284 case RECV_IDLE:
285 del_timer(timer: &ssi->rx_wd);
286 if (ssi->send_state == SEND_IDLE)
287 del_timer(timer: &ssi->keep_alive);
288 break;
289 case RECV_READY:
290 /* CMT speech workaround */
291 if (atomic_read(v: &ssi->tx_usecnt))
292 break;
293 fallthrough;
294 case RECEIVING:
295 mod_timer(timer: &ssi->keep_alive, expires: jiffies +
296 msecs_to_jiffies(SSIP_KATOUT));
297 mod_timer(timer: &ssi->rx_wd, expires: jiffies + msecs_to_jiffies(SSIP_WDTOUT));
298 break;
299 default:
300 break;
301 }
302}
303
304static void ssip_set_txstate(struct ssi_protocol *ssi, unsigned int state)
305{
306 ssi->send_state = state;
307 switch (state) {
308 case SEND_IDLE:
309 case SEND_READY:
310 del_timer(timer: &ssi->tx_wd);
311 if (ssi->recv_state == RECV_IDLE)
312 del_timer(timer: &ssi->keep_alive);
313 break;
314 case WAIT4READY:
315 case SENDING:
316 case SENDING_SWBREAK:
317 mod_timer(timer: &ssi->keep_alive,
318 expires: jiffies + msecs_to_jiffies(SSIP_KATOUT));
319 mod_timer(timer: &ssi->tx_wd, expires: jiffies + msecs_to_jiffies(SSIP_WDTOUT));
320 break;
321 default:
322 break;
323 }
324}
325
326struct hsi_client *ssip_slave_get_master(struct hsi_client *slave)
327{
328 struct hsi_client *master = ERR_PTR(error: -ENODEV);
329 struct ssi_protocol *ssi;
330
331 list_for_each_entry(ssi, &ssip_list, link)
332 if (slave->device.parent == ssi->cl->device.parent) {
333 master = ssi->cl;
334 break;
335 }
336
337 return master;
338}
339EXPORT_SYMBOL_GPL(ssip_slave_get_master);
340
341int ssip_slave_start_tx(struct hsi_client *master)
342{
343 struct ssi_protocol *ssi = hsi_client_drvdata(cl: master);
344
345 dev_dbg(&master->device, "start TX %d\n", atomic_read(&ssi->tx_usecnt));
346 spin_lock_bh(lock: &ssi->lock);
347 if (ssi->send_state == SEND_IDLE) {
348 ssip_set_txstate(ssi, state: WAIT4READY);
349 hsi_start_tx(cl: master);
350 }
351 spin_unlock_bh(lock: &ssi->lock);
352 atomic_inc(v: &ssi->tx_usecnt);
353
354 return 0;
355}
356EXPORT_SYMBOL_GPL(ssip_slave_start_tx);
357
358int ssip_slave_stop_tx(struct hsi_client *master)
359{
360 struct ssi_protocol *ssi = hsi_client_drvdata(cl: master);
361
362 WARN_ON_ONCE(atomic_read(&ssi->tx_usecnt) == 0);
363
364 if (atomic_dec_and_test(v: &ssi->tx_usecnt)) {
365 spin_lock_bh(lock: &ssi->lock);
366 if ((ssi->send_state == SEND_READY) ||
367 (ssi->send_state == WAIT4READY)) {
368 ssip_set_txstate(ssi, state: SEND_IDLE);
369 hsi_stop_tx(cl: master);
370 }
371 spin_unlock_bh(lock: &ssi->lock);
372 }
373 dev_dbg(&master->device, "stop TX %d\n", atomic_read(&ssi->tx_usecnt));
374
375 return 0;
376}
377EXPORT_SYMBOL_GPL(ssip_slave_stop_tx);
378
379int ssip_slave_running(struct hsi_client *master)
380{
381 struct ssi_protocol *ssi = hsi_client_drvdata(cl: master);
382 return netif_running(dev: ssi->netdev);
383}
384EXPORT_SYMBOL_GPL(ssip_slave_running);
385
386static void ssip_reset(struct hsi_client *cl)
387{
388 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
389 struct list_head *head, *tmp;
390 struct hsi_msg *msg;
391
392 if (netif_running(dev: ssi->netdev))
393 netif_carrier_off(dev: ssi->netdev);
394 hsi_flush(cl);
395 spin_lock_bh(lock: &ssi->lock);
396 if (ssi->send_state != SEND_IDLE)
397 hsi_stop_tx(cl);
398 spin_unlock_bh(lock: &ssi->lock);
399 if (test_and_clear_bit(SSIP_WAKETEST_FLAG, addr: &ssi->flags))
400 ssi_waketest(cl, enable: 0); /* FIXME: To be removed */
401 spin_lock_bh(lock: &ssi->lock);
402 del_timer(timer: &ssi->rx_wd);
403 del_timer(timer: &ssi->tx_wd);
404 del_timer(timer: &ssi->keep_alive);
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(entry: head);
415 ssip_free_data(msg);
416 }
417 ssi->txqueue_len = 0;
418 spin_unlock_bh(lock: &ssi->lock);
419}
420
421static 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(lock: &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(lock: &ssi->lock);
440}
441
442static 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
454static 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(lock: &ssi->lock);
463 if (ssi->recv_state == RECV_IDLE)
464 switch (ssi->send_state) {
465 case SEND_READY:
466 if (atomic_read(v: &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(lock: &ssi->lock);
475 return;
476 }
477 mod_timer(timer: &ssi->keep_alive, expires: jiffies + msecs_to_jiffies(SSIP_KATOUT));
478 spin_unlock(lock: &ssi->lock);
479}
480
481static 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
490static 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
499static 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
515static 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(lock: &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(lock: &ssi->lock);
529 return;
530 }
531 ssip_set_rxstate(ssi, state: RECV_READY);
532 spin_unlock_bh(lock: &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
541static 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(lock: &ssi->lock);
547 if (likely(ssi->main_state == ACTIVE))
548 ssip_set_rxstate(ssi, state: RECV_IDLE);
549 spin_unlock_bh(lock: &ssi->lock);
550}
551
552static void ssip_free_strans(struct hsi_msg *msg)
553{
554 ssip_free_data(msg: msg->context);
555 ssip_release_cmd(msg);
556}
557
558static 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(lock: &ssi->lock);
567 ssip_set_txstate(ssi, state: SENDING);
568 spin_unlock_bh(lock: &ssi->lock);
569 hsi_async_write(cl, msg: data);
570}
571
572static 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(lock: &ssi->lock);
579 if (list_empty(head: &ssi->txqueue)) {
580 spin_unlock_bh(lock: &ssi->lock);
581 return 0;
582 }
583 dmsg = list_first_entry(&ssi->txqueue, struct hsi_msg, link);
584 list_del(entry: &dmsg->link);
585 ssi->txqueue_len--;
586 spin_unlock_bh(lock: &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(lock: &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, state: SENDING);
599 spin_unlock_bh(lock: &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 */
608static 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, len: 1);
636 netif_rx(skb);
637}
638
639static 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 del_timer(timer: &ssi->rx_wd); /* FIXME: Revisit */
652 skb = msg->context;
653 ssip_pn_rx(skb);
654 hsi_free_msg(msg);
655}
656
657static 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(lock: &ssi->lock);
674 ssi->main_state = HANDSHAKE;
675 spin_unlock_bh(lock: &ssi->lock);
676
677 if (!test_and_set_bit(SSIP_WAKETEST_FLAG, addr: &ssi->flags))
678 ssi_waketest(cl, enable: 1); /* FIXME: To be removed */
679
680 spin_lock_bh(lock: &ssi->lock);
681 /* Start boot handshake watchdog */
682 mod_timer(timer: &ssi->tx_wd, expires: jiffies + msecs_to_jiffies(SSIP_WDTOUT));
683 spin_unlock_bh(lock: &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
698static 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(lock: &ssi->lock);
706 if (ssi->main_state != ACTIVE)
707 /* Use tx_wd as a boot watchdog in non ACTIVE state */
708 mod_timer(timer: &ssi->tx_wd, expires: 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(lock: &ssi->lock);
713}
714
715static 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(lock: &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(lock: &ssi->lock);
725 return;
726 }
727 spin_unlock_bh(lock: &ssi->lock);
728
729 if (test_and_clear_bit(SSIP_WAKETEST_FLAG, addr: &ssi->flags))
730 ssi_waketest(cl, enable: 0); /* FIXME: To be removed */
731
732 spin_lock_bh(lock: &ssi->lock);
733 ssi->main_state = ACTIVE;
734 del_timer(timer: &ssi->tx_wd); /* Stop boot handshake timer */
735 spin_unlock_bh(lock: &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(dev: ssi->netdev);
745 netif_carrier_on(dev: ssi->netdev);
746}
747
748static void ssip_rx_ready(struct hsi_client *cl)
749{
750 struct ssi_protocol *ssi = hsi_client_drvdata(cl);
751
752 spin_lock_bh(lock: &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(lock: &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(lock: &ssi->lock);
762 return;
763 }
764 ssip_set_txstate(ssi, state: SEND_READY);
765 spin_unlock_bh(lock: &ssi->lock);
766 ssip_xmit(cl);
767}
768
769static 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(lock: &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(lock: &ssi->lock);
782 return;
783 }
784 ssip_set_rxstate(ssi, state: 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(lock: &ssi->lock);
789 goto out1;
790 }
791 ssi->rxid++;
792 spin_unlock_bh(lock: &ssi->lock);
793 skb = netdev_alloc_skb(dev: ssi->netdev, length: 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: 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;
808out2:
809 dev_kfree_skb(skb);
810out1:
811 ssip_error(cl);
812}
813
814static 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
853static 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(lock: &ssi->lock);
860 if (list_empty(head: &ssi->txqueue)) {
861 if (atomic_read(v: &ssi->tx_usecnt)) {
862 ssip_set_txstate(ssi, state: SEND_READY);
863 } else {
864 ssip_set_txstate(ssi, state: SEND_IDLE);
865 hsi_stop_tx(cl);
866 }
867 spin_unlock_bh(lock: &ssi->lock);
868 } else {
869 spin_unlock_bh(lock: &ssi->lock);
870 ssip_xmit(cl);
871 }
872 netif_wake_queue(dev: ssi->netdev);
873}
874
875static 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(lock: &ssi->lock);
887 if (list_empty(head: &ssi->txqueue)) {
888 ssip_set_txstate(ssi, state: SENDING_SWBREAK);
889 spin_unlock_bh(lock: &ssi->lock);
890 cmsg = ssip_claim_cmd(ssi);
891 ssip_set_cmd(msg: cmsg, SSIP_SWBREAK_CMD);
892 cmsg->complete = ssip_swbreak_complete;
893 dev_dbg(&cl->device, "Send SWBREAK\n");
894 hsi_async_write(cl, msg: cmsg);
895 } else {
896 spin_unlock_bh(lock: &ssi->lock);
897 ssip_xmit(cl);
898 }
899out:
900 ssip_free_data(msg);
901}
902
903static 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
917static 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, share: 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, handler: 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, addr: &ssi->flags))
939 ssi_waketest(cl, enable: 1); /* FIXME: To be removed */
940
941 spin_lock_bh(lock: &ssi->lock);
942 ssi->main_state = HANDSHAKE;
943 spin_unlock_bh(lock: &ssi->lock);
944
945 ssip_send_bootinfo_req_cmd(cl);
946
947 return 0;
948}
949
950static 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
961static 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
970static 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, pad: 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, headroom: 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(lock: &ssi->lock);
1001 if (unlikely(ssi->main_state != ACTIVE)) {
1002 spin_unlock_bh(lock: &ssi->lock);
1003 dev_dbg(&cl->device, "Dropping tx data: CMT is OFFLINE\n");
1004 goto drop2;
1005 }
1006 list_add_tail(new: &msg->link, head: &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, state: WAIT4READY);
1014 spin_unlock_bh(lock: &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(lock: &ssi->lock);
1022 schedule_work(work: &ssi->work);
1023 } else {
1024 spin_unlock_bh(lock: &ssi->lock);
1025 }
1026 dev->stats.tx_packets++;
1027 dev->stats.tx_bytes += skb->len;
1028
1029 return NETDEV_TX_OK;
1030drop2:
1031 hsi_free_msg(msg);
1032drop:
1033 dev_kfree_skb(skb);
1034inc_dropped:
1035 dev->stats.tx_dropped++;
1036
1037 return NETDEV_TX_OK;
1038}
1039
1040/* CMT reset event handler */
1041void ssip_reset_event(struct hsi_client *master)
1042{
1043 struct ssi_protocol *ssi = hsi_client_drvdata(cl: master);
1044 dev_err(&ssi->cl->device, "CMT reset detected!\n");
1045 ssip_error(cl: ssi->cl);
1046}
1047EXPORT_SYMBOL_GPL(ssip_reset_event);
1048
1049static 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
1055static 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: &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
1073static 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(size: 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(list: &ssi->txqueue);
1089 INIT_LIST_HEAD(list: &ssi->cmdqueue);
1090 atomic_set(v: &ssi->tx_usecnt, i: 0);
1091 hsi_client_set_drvdata(cl, data: 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, name: "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, name: "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(dev: ssi->netdev);
1128 err = register_netdev(dev: ssi->netdev);
1129 if (err < 0) {
1130 dev_err(dev, "Register netdev failed (%d)\n", err);
1131 goto out2;
1132 }
1133
1134 list_add(new: &ssi->link, head: &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;
1140out2:
1141 free_netdev(dev: ssi->netdev);
1142out1:
1143 ssip_free_cmds(ssi);
1144out:
1145 kfree(objp: ssi);
1146
1147 return err;
1148}
1149
1150static 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(entry: &ssi->link);
1156 unregister_netdev(dev: ssi->netdev);
1157 ssip_free_cmds(ssi);
1158 hsi_client_set_drvdata(cl, NULL);
1159 kfree(objp: ssi);
1160
1161 return 0;
1162}
1163
1164static 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
1173static int __init ssip_init(void)
1174{
1175 pr_info("SSI protocol aka McSAAB added\n");
1176
1177 return hsi_register_client_driver(drv: &ssip_driver);
1178}
1179module_init(ssip_init);
1180
1181static void __exit ssip_exit(void)
1182{
1183 hsi_unregister_client_driver(drv: &ssip_driver);
1184 pr_info("SSI protocol driver removed\n");
1185}
1186module_exit(ssip_exit);
1187
1188MODULE_ALIAS("hsi:ssi-protocol");
1189MODULE_AUTHOR("Carlos Chinea <carlos.chinea@nokia.com>");
1190MODULE_AUTHOR("Remi Denis-Courmont <remi.denis-courmont@nokia.com>");
1191MODULE_DESCRIPTION("SSI protocol improved aka McSAAB");
1192MODULE_LICENSE("GPL");
1193

source code of linux/drivers/hsi/clients/ssi_protocol.c