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caif-hsi: robust frame aggregation for HSI
[deliverable/linux.git] / drivers / net / caif / caif_hsi.c
1 /*
2 * Copyright (C) ST-Ericsson AB 2010
3 * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
4 * Author: Daniel Martensson / daniel.martensson@stericsson.com
5 * Dmitry.Tarnyagin / dmitry.tarnyagin@stericsson.com
6 * License terms: GNU General Public License (GPL) version 2.
7 */
8
9 #include <linux/init.h>
10 #include <linux/module.h>
11 #include <linux/device.h>
12 #include <linux/platform_device.h>
13 #include <linux/netdevice.h>
14 #include <linux/string.h>
15 #include <linux/list.h>
16 #include <linux/interrupt.h>
17 #include <linux/delay.h>
18 #include <linux/sched.h>
19 #include <linux/if_arp.h>
20 #include <linux/timer.h>
21 #include <linux/rtnetlink.h>
22 #include <linux/pkt_sched.h>
23 #include <net/caif/caif_layer.h>
24 #include <net/caif/caif_hsi.h>
25
26 MODULE_LICENSE("GPL");
27 MODULE_AUTHOR("Daniel Martensson<daniel.martensson@stericsson.com>");
28 MODULE_DESCRIPTION("CAIF HSI driver");
29
30 /* Returns the number of padding bytes for alignment. */
31 #define PAD_POW2(x, pow) ((((x)&((pow)-1)) == 0) ? 0 :\
32 (((pow)-((x)&((pow)-1)))))
33
34 static int inactivity_timeout = 1000;
35 module_param(inactivity_timeout, int, S_IRUGO | S_IWUSR);
36 MODULE_PARM_DESC(inactivity_timeout, "Inactivity timeout on HSI, ms.");
37
38 static int aggregation_timeout = 1;
39 module_param(aggregation_timeout, int, S_IRUGO | S_IWUSR);
40 MODULE_PARM_DESC(aggregation_timeout, "Aggregation timeout on HSI, ms.");
41
42 /*
43 * HSI padding options.
44 * Warning: must be a base of 2 (& operation used) and can not be zero !
45 */
46 static int hsi_head_align = 4;
47 module_param(hsi_head_align, int, S_IRUGO);
48 MODULE_PARM_DESC(hsi_head_align, "HSI head alignment.");
49
50 static int hsi_tail_align = 4;
51 module_param(hsi_tail_align, int, S_IRUGO);
52 MODULE_PARM_DESC(hsi_tail_align, "HSI tail alignment.");
53
54 /*
55 * HSI link layer flowcontrol thresholds.
56 * Warning: A high threshold value migth increase throughput but it will at
57 * the same time prevent channel prioritization and increase the risk of
58 * flooding the modem. The high threshold should be above the low.
59 */
60 static int hsi_high_threshold = 100;
61 module_param(hsi_high_threshold, int, S_IRUGO);
62 MODULE_PARM_DESC(hsi_high_threshold, "HSI high threshold (FLOW OFF).");
63
64 static int hsi_low_threshold = 50;
65 module_param(hsi_low_threshold, int, S_IRUGO);
66 MODULE_PARM_DESC(hsi_low_threshold, "HSI high threshold (FLOW ON).");
67
68 #define ON 1
69 #define OFF 0
70
71 /*
72 * Threshold values for the HSI packet queue. Flowcontrol will be asserted
73 * when the number of packets exceeds HIGH_WATER_MARK. It will not be
74 * de-asserted before the number of packets drops below LOW_WATER_MARK.
75 */
76 #define LOW_WATER_MARK hsi_low_threshold
77 #define HIGH_WATER_MARK hsi_high_threshold
78
79 static LIST_HEAD(cfhsi_list);
80 static spinlock_t cfhsi_list_lock;
81
82 static void cfhsi_inactivity_tout(unsigned long arg)
83 {
84 struct cfhsi *cfhsi = (struct cfhsi *)arg;
85
86 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
87 __func__);
88
89 /* Schedule power down work queue. */
90 if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
91 queue_work(cfhsi->wq, &cfhsi->wake_down_work);
92 }
93
94 static void cfhsi_update_aggregation_stats(struct cfhsi *cfhsi,
95 const struct sk_buff *skb,
96 int direction)
97 {
98 struct caif_payload_info *info;
99 int hpad, tpad, len;
100
101 info = (struct caif_payload_info *)&skb->cb;
102 hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
103 tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);
104 len = skb->len + hpad + tpad;
105
106 if (direction > 0)
107 cfhsi->aggregation_len += len;
108 else if (direction < 0)
109 cfhsi->aggregation_len -= len;
110 }
111
112 static bool cfhsi_can_send_aggregate(struct cfhsi *cfhsi)
113 {
114 int i;
115
116 if (cfhsi->aggregation_timeout < 0)
117 return true;
118
119 for (i = 0; i < CFHSI_PRIO_BEBK; ++i) {
120 if (cfhsi->qhead[i].qlen)
121 return true;
122 }
123
124 /* TODO: Use aggregation_len instead */
125 if (cfhsi->qhead[CFHSI_PRIO_BEBK].qlen >= CFHSI_MAX_PKTS)
126 return true;
127
128 return false;
129 }
130
131 static struct sk_buff *cfhsi_dequeue(struct cfhsi *cfhsi)
132 {
133 struct sk_buff *skb;
134 int i;
135
136 for (i = 0; i < CFHSI_PRIO_LAST; ++i) {
137 skb = skb_dequeue(&cfhsi->qhead[i]);
138 if (skb)
139 break;
140 }
141
142 return skb;
143 }
144
145 static int cfhsi_tx_queue_len(struct cfhsi *cfhsi)
146 {
147 int i, len = 0;
148 for (i = 0; i < CFHSI_PRIO_LAST; ++i)
149 len += skb_queue_len(&cfhsi->qhead[i]);
150 return len;
151 }
152
153 static void cfhsi_abort_tx(struct cfhsi *cfhsi)
154 {
155 struct sk_buff *skb;
156
157 for (;;) {
158 spin_lock_bh(&cfhsi->lock);
159 skb = cfhsi_dequeue(cfhsi);
160 if (!skb)
161 break;
162
163 cfhsi->ndev->stats.tx_errors++;
164 cfhsi->ndev->stats.tx_dropped++;
165 cfhsi_update_aggregation_stats(cfhsi, skb, -1);
166 spin_unlock_bh(&cfhsi->lock);
167 kfree_skb(skb);
168 }
169 cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
170 if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
171 mod_timer(&cfhsi->inactivity_timer,
172 jiffies + cfhsi->inactivity_timeout);
173 spin_unlock_bh(&cfhsi->lock);
174 }
175
176 static int cfhsi_flush_fifo(struct cfhsi *cfhsi)
177 {
178 char buffer[32]; /* Any reasonable value */
179 size_t fifo_occupancy;
180 int ret;
181
182 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
183 __func__);
184
185 do {
186 ret = cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
187 &fifo_occupancy);
188 if (ret) {
189 dev_warn(&cfhsi->ndev->dev,
190 "%s: can't get FIFO occupancy: %d.\n",
191 __func__, ret);
192 break;
193 } else if (!fifo_occupancy)
194 /* No more data, exitting normally */
195 break;
196
197 fifo_occupancy = min(sizeof(buffer), fifo_occupancy);
198 set_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
199 ret = cfhsi->dev->cfhsi_rx(buffer, fifo_occupancy,
200 cfhsi->dev);
201 if (ret) {
202 clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
203 dev_warn(&cfhsi->ndev->dev,
204 "%s: can't read data: %d.\n",
205 __func__, ret);
206 break;
207 }
208
209 ret = 5 * HZ;
210 ret = wait_event_interruptible_timeout(cfhsi->flush_fifo_wait,
211 !test_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits), ret);
212
213 if (ret < 0) {
214 dev_warn(&cfhsi->ndev->dev,
215 "%s: can't wait for flush complete: %d.\n",
216 __func__, ret);
217 break;
218 } else if (!ret) {
219 ret = -ETIMEDOUT;
220 dev_warn(&cfhsi->ndev->dev,
221 "%s: timeout waiting for flush complete.\n",
222 __func__);
223 break;
224 }
225 } while (1);
226
227 return ret;
228 }
229
230 static int cfhsi_tx_frm(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
231 {
232 int nfrms = 0;
233 int pld_len = 0;
234 struct sk_buff *skb;
235 u8 *pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
236
237 skb = cfhsi_dequeue(cfhsi);
238 if (!skb)
239 return 0;
240
241 /* Clear offset. */
242 desc->offset = 0;
243
244 /* Check if we can embed a CAIF frame. */
245 if (skb->len < CFHSI_MAX_EMB_FRM_SZ) {
246 struct caif_payload_info *info;
247 int hpad = 0;
248 int tpad = 0;
249
250 /* Calculate needed head alignment and tail alignment. */
251 info = (struct caif_payload_info *)&skb->cb;
252
253 hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
254 tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);
255
256 /* Check if frame still fits with added alignment. */
257 if ((skb->len + hpad + tpad) <= CFHSI_MAX_EMB_FRM_SZ) {
258 u8 *pemb = desc->emb_frm;
259 desc->offset = CFHSI_DESC_SHORT_SZ;
260 *pemb = (u8)(hpad - 1);
261 pemb += hpad;
262
263 /* Update network statistics. */
264 spin_lock_bh(&cfhsi->lock);
265 cfhsi->ndev->stats.tx_packets++;
266 cfhsi->ndev->stats.tx_bytes += skb->len;
267 cfhsi_update_aggregation_stats(cfhsi, skb, -1);
268 spin_unlock_bh(&cfhsi->lock);
269
270 /* Copy in embedded CAIF frame. */
271 skb_copy_bits(skb, 0, pemb, skb->len);
272
273 /* Consume the SKB */
274 consume_skb(skb);
275 skb = NULL;
276 }
277 }
278
279 /* Create payload CAIF frames. */
280 pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
281 while (nfrms < CFHSI_MAX_PKTS) {
282 struct caif_payload_info *info;
283 int hpad = 0;
284 int tpad = 0;
285
286 if (!skb)
287 skb = cfhsi_dequeue(cfhsi);
288
289 if (!skb)
290 break;
291
292 /* Calculate needed head alignment and tail alignment. */
293 info = (struct caif_payload_info *)&skb->cb;
294
295 hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
296 tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);
297
298 /* Fill in CAIF frame length in descriptor. */
299 desc->cffrm_len[nfrms] = hpad + skb->len + tpad;
300
301 /* Fill head padding information. */
302 *pfrm = (u8)(hpad - 1);
303 pfrm += hpad;
304
305 /* Update network statistics. */
306 spin_lock_bh(&cfhsi->lock);
307 cfhsi->ndev->stats.tx_packets++;
308 cfhsi->ndev->stats.tx_bytes += skb->len;
309 cfhsi_update_aggregation_stats(cfhsi, skb, -1);
310 spin_unlock_bh(&cfhsi->lock);
311
312 /* Copy in CAIF frame. */
313 skb_copy_bits(skb, 0, pfrm, skb->len);
314
315 /* Update payload length. */
316 pld_len += desc->cffrm_len[nfrms];
317
318 /* Update frame pointer. */
319 pfrm += skb->len + tpad;
320
321 /* Consume the SKB */
322 consume_skb(skb);
323 skb = NULL;
324
325 /* Update number of frames. */
326 nfrms++;
327 }
328
329 /* Unused length fields should be zero-filled (according to SPEC). */
330 while (nfrms < CFHSI_MAX_PKTS) {
331 desc->cffrm_len[nfrms] = 0x0000;
332 nfrms++;
333 }
334
335 /* Check if we can piggy-back another descriptor. */
336 if (cfhsi_can_send_aggregate(cfhsi))
337 desc->header |= CFHSI_PIGGY_DESC;
338 else
339 desc->header &= ~CFHSI_PIGGY_DESC;
340
341 return CFHSI_DESC_SZ + pld_len;
342 }
343
344 static void cfhsi_start_tx(struct cfhsi *cfhsi)
345 {
346 struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
347 int len, res;
348
349 dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);
350
351 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
352 return;
353
354 do {
355 /* Create HSI frame. */
356 len = cfhsi_tx_frm(desc, cfhsi);
357 if (!len) {
358 spin_lock_bh(&cfhsi->lock);
359 if (unlikely(cfhsi_tx_queue_len(cfhsi))) {
360 spin_unlock_bh(&cfhsi->lock);
361 res = -EAGAIN;
362 continue;
363 }
364 cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
365 /* Start inactivity timer. */
366 mod_timer(&cfhsi->inactivity_timer,
367 jiffies + cfhsi->inactivity_timeout);
368 spin_unlock_bh(&cfhsi->lock);
369 break;
370 }
371
372 /* Set up new transfer. */
373 res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
374 if (WARN_ON(res < 0))
375 dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
376 __func__, res);
377 } while (res < 0);
378 }
379
380 static void cfhsi_tx_done(struct cfhsi *cfhsi)
381 {
382 dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);
383
384 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
385 return;
386
387 /*
388 * Send flow on if flow off has been previously signalled
389 * and number of packets is below low water mark.
390 */
391 spin_lock_bh(&cfhsi->lock);
392 if (cfhsi->flow_off_sent &&
393 cfhsi_tx_queue_len(cfhsi) <= cfhsi->q_low_mark &&
394 cfhsi->cfdev.flowctrl) {
395
396 cfhsi->flow_off_sent = 0;
397 cfhsi->cfdev.flowctrl(cfhsi->ndev, ON);
398 }
399
400 if (cfhsi_can_send_aggregate(cfhsi)) {
401 spin_unlock_bh(&cfhsi->lock);
402 cfhsi_start_tx(cfhsi);
403 } else {
404 mod_timer(&cfhsi->aggregation_timer,
405 jiffies + cfhsi->aggregation_timeout);
406 spin_unlock_bh(&cfhsi->lock);
407 }
408
409 return;
410 }
411
412 static void cfhsi_tx_done_cb(struct cfhsi_drv *drv)
413 {
414 struct cfhsi *cfhsi;
415
416 cfhsi = container_of(drv, struct cfhsi, drv);
417 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
418 __func__);
419
420 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
421 return;
422 cfhsi_tx_done(cfhsi);
423 }
424
425 static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
426 {
427 int xfer_sz = 0;
428 int nfrms = 0;
429 u16 *plen = NULL;
430 u8 *pfrm = NULL;
431
432 if ((desc->header & ~CFHSI_PIGGY_DESC) ||
433 (desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
434 dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n",
435 __func__);
436 return -EPROTO;
437 }
438
439 /* Check for embedded CAIF frame. */
440 if (desc->offset) {
441 struct sk_buff *skb;
442 u8 *dst = NULL;
443 int len = 0;
444 pfrm = ((u8 *)desc) + desc->offset;
445
446 /* Remove offset padding. */
447 pfrm += *pfrm + 1;
448
449 /* Read length of CAIF frame (little endian). */
450 len = *pfrm;
451 len |= ((*(pfrm+1)) << 8) & 0xFF00;
452 len += 2; /* Add FCS fields. */
453
454 /* Sanity check length of CAIF frame. */
455 if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
456 dev_err(&cfhsi->ndev->dev, "%s: Invalid length.\n",
457 __func__);
458 return -EPROTO;
459 }
460
461 /* Allocate SKB (OK even in IRQ context). */
462 skb = alloc_skb(len + 1, GFP_ATOMIC);
463 if (!skb) {
464 dev_err(&cfhsi->ndev->dev, "%s: Out of memory !\n",
465 __func__);
466 return -ENOMEM;
467 }
468 caif_assert(skb != NULL);
469
470 dst = skb_put(skb, len);
471 memcpy(dst, pfrm, len);
472
473 skb->protocol = htons(ETH_P_CAIF);
474 skb_reset_mac_header(skb);
475 skb->dev = cfhsi->ndev;
476
477 /*
478 * We are called from a arch specific platform device.
479 * Unfortunately we don't know what context we're
480 * running in.
481 */
482 if (in_interrupt())
483 netif_rx(skb);
484 else
485 netif_rx_ni(skb);
486
487 /* Update network statistics. */
488 cfhsi->ndev->stats.rx_packets++;
489 cfhsi->ndev->stats.rx_bytes += len;
490 }
491
492 /* Calculate transfer length. */
493 plen = desc->cffrm_len;
494 while (nfrms < CFHSI_MAX_PKTS && *plen) {
495 xfer_sz += *plen;
496 plen++;
497 nfrms++;
498 }
499
500 /* Check for piggy-backed descriptor. */
501 if (desc->header & CFHSI_PIGGY_DESC)
502 xfer_sz += CFHSI_DESC_SZ;
503
504 if ((xfer_sz % 4) || (xfer_sz > (CFHSI_BUF_SZ_RX - CFHSI_DESC_SZ))) {
505 dev_err(&cfhsi->ndev->dev,
506 "%s: Invalid payload len: %d, ignored.\n",
507 __func__, xfer_sz);
508 return -EPROTO;
509 }
510 return xfer_sz;
511 }
512
513 static int cfhsi_rx_desc_len(struct cfhsi_desc *desc)
514 {
515 int xfer_sz = 0;
516 int nfrms = 0;
517 u16 *plen;
518
519 if ((desc->header & ~CFHSI_PIGGY_DESC) ||
520 (desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
521
522 pr_err("Invalid descriptor. %x %x\n", desc->header,
523 desc->offset);
524 return -EPROTO;
525 }
526
527 /* Calculate transfer length. */
528 plen = desc->cffrm_len;
529 while (nfrms < CFHSI_MAX_PKTS && *plen) {
530 xfer_sz += *plen;
531 plen++;
532 nfrms++;
533 }
534
535 if (xfer_sz % 4) {
536 pr_err("Invalid payload len: %d, ignored.\n", xfer_sz);
537 return -EPROTO;
538 }
539 return xfer_sz;
540 }
541
542 static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
543 {
544 int rx_sz = 0;
545 int nfrms = 0;
546 u16 *plen = NULL;
547 u8 *pfrm = NULL;
548
549 /* Sanity check header and offset. */
550 if (WARN_ON((desc->header & ~CFHSI_PIGGY_DESC) ||
551 (desc->offset > CFHSI_MAX_EMB_FRM_SZ))) {
552 dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n",
553 __func__);
554 return -EPROTO;
555 }
556
557 /* Set frame pointer to start of payload. */
558 pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
559 plen = desc->cffrm_len;
560
561 /* Skip already processed frames. */
562 while (nfrms < cfhsi->rx_state.nfrms) {
563 pfrm += *plen;
564 rx_sz += *plen;
565 plen++;
566 nfrms++;
567 }
568
569 /* Parse payload. */
570 while (nfrms < CFHSI_MAX_PKTS && *plen) {
571 struct sk_buff *skb;
572 u8 *dst = NULL;
573 u8 *pcffrm = NULL;
574 int len = 0;
575
576 /* CAIF frame starts after head padding. */
577 pcffrm = pfrm + *pfrm + 1;
578
579 /* Read length of CAIF frame (little endian). */
580 len = *pcffrm;
581 len |= ((*(pcffrm + 1)) << 8) & 0xFF00;
582 len += 2; /* Add FCS fields. */
583
584 /* Sanity check length of CAIF frames. */
585 if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
586 dev_err(&cfhsi->ndev->dev, "%s: Invalid length.\n",
587 __func__);
588 return -EPROTO;
589 }
590
591 /* Allocate SKB (OK even in IRQ context). */
592 skb = alloc_skb(len + 1, GFP_ATOMIC);
593 if (!skb) {
594 dev_err(&cfhsi->ndev->dev, "%s: Out of memory !\n",
595 __func__);
596 cfhsi->rx_state.nfrms = nfrms;
597 return -ENOMEM;
598 }
599 caif_assert(skb != NULL);
600
601 dst = skb_put(skb, len);
602 memcpy(dst, pcffrm, len);
603
604 skb->protocol = htons(ETH_P_CAIF);
605 skb_reset_mac_header(skb);
606 skb->dev = cfhsi->ndev;
607
608 /*
609 * We're called from a platform device,
610 * and don't know the context we're running in.
611 */
612 if (in_interrupt())
613 netif_rx(skb);
614 else
615 netif_rx_ni(skb);
616
617 /* Update network statistics. */
618 cfhsi->ndev->stats.rx_packets++;
619 cfhsi->ndev->stats.rx_bytes += len;
620
621 pfrm += *plen;
622 rx_sz += *plen;
623 plen++;
624 nfrms++;
625 }
626
627 return rx_sz;
628 }
629
630 static void cfhsi_rx_done(struct cfhsi *cfhsi)
631 {
632 int res;
633 int desc_pld_len = 0, rx_len, rx_state;
634 struct cfhsi_desc *desc = NULL;
635 u8 *rx_ptr, *rx_buf;
636 struct cfhsi_desc *piggy_desc = NULL;
637
638 desc = (struct cfhsi_desc *)cfhsi->rx_buf;
639
640 dev_dbg(&cfhsi->ndev->dev, "%s\n", __func__);
641
642 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
643 return;
644
645 /* Update inactivity timer if pending. */
646 spin_lock_bh(&cfhsi->lock);
647 mod_timer_pending(&cfhsi->inactivity_timer,
648 jiffies + cfhsi->inactivity_timeout);
649 spin_unlock_bh(&cfhsi->lock);
650
651 if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
652 desc_pld_len = cfhsi_rx_desc_len(desc);
653
654 if (desc_pld_len < 0)
655 goto out_of_sync;
656
657 rx_buf = cfhsi->rx_buf;
658 rx_len = desc_pld_len;
659 if (desc_pld_len > 0 && (desc->header & CFHSI_PIGGY_DESC))
660 rx_len += CFHSI_DESC_SZ;
661 if (desc_pld_len == 0)
662 rx_buf = cfhsi->rx_flip_buf;
663 } else {
664 rx_buf = cfhsi->rx_flip_buf;
665
666 rx_len = CFHSI_DESC_SZ;
667 if (cfhsi->rx_state.pld_len > 0 &&
668 (desc->header & CFHSI_PIGGY_DESC)) {
669
670 piggy_desc = (struct cfhsi_desc *)
671 (desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ +
672 cfhsi->rx_state.pld_len);
673
674 cfhsi->rx_state.piggy_desc = true;
675
676 /* Extract payload len from piggy-backed descriptor. */
677 desc_pld_len = cfhsi_rx_desc_len(piggy_desc);
678 if (desc_pld_len < 0)
679 goto out_of_sync;
680
681 if (desc_pld_len > 0)
682 rx_len = desc_pld_len;
683
684 if (desc_pld_len > 0 &&
685 (piggy_desc->header & CFHSI_PIGGY_DESC))
686 rx_len += CFHSI_DESC_SZ;
687
688 /*
689 * Copy needed information from the piggy-backed
690 * descriptor to the descriptor in the start.
691 */
692 memcpy(rx_buf, (u8 *)piggy_desc,
693 CFHSI_DESC_SHORT_SZ);
694 /* Mark no embedded frame here */
695 piggy_desc->offset = 0;
696 if (desc_pld_len == -EPROTO)
697 goto out_of_sync;
698 }
699 }
700
701 if (desc_pld_len) {
702 rx_state = CFHSI_RX_STATE_PAYLOAD;
703 rx_ptr = rx_buf + CFHSI_DESC_SZ;
704 } else {
705 rx_state = CFHSI_RX_STATE_DESC;
706 rx_ptr = rx_buf;
707 rx_len = CFHSI_DESC_SZ;
708 }
709
710 /* Initiate next read */
711 if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) {
712 /* Set up new transfer. */
713 dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n",
714 __func__);
715
716 res = cfhsi->dev->cfhsi_rx(rx_ptr, rx_len,
717 cfhsi->dev);
718 if (WARN_ON(res < 0)) {
719 dev_err(&cfhsi->ndev->dev, "%s: RX error %d.\n",
720 __func__, res);
721 cfhsi->ndev->stats.rx_errors++;
722 cfhsi->ndev->stats.rx_dropped++;
723 }
724 }
725
726 if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
727 /* Extract payload from descriptor */
728 if (cfhsi_rx_desc(desc, cfhsi) < 0)
729 goto out_of_sync;
730 } else {
731 /* Extract payload */
732 if (cfhsi_rx_pld(desc, cfhsi) < 0)
733 goto out_of_sync;
734 if (piggy_desc) {
735 /* Extract any payload in piggyback descriptor. */
736 if (cfhsi_rx_desc(piggy_desc, cfhsi) < 0)
737 goto out_of_sync;
738 }
739 }
740
741 /* Update state info */
742 memset(&cfhsi->rx_state, 0, sizeof(cfhsi->rx_state));
743 cfhsi->rx_state.state = rx_state;
744 cfhsi->rx_ptr = rx_ptr;
745 cfhsi->rx_len = rx_len;
746 cfhsi->rx_state.pld_len = desc_pld_len;
747 cfhsi->rx_state.piggy_desc = desc->header & CFHSI_PIGGY_DESC;
748
749 if (rx_buf != cfhsi->rx_buf)
750 swap(cfhsi->rx_buf, cfhsi->rx_flip_buf);
751 return;
752
753 out_of_sync:
754 dev_err(&cfhsi->ndev->dev, "%s: Out of sync.\n", __func__);
755 print_hex_dump_bytes("--> ", DUMP_PREFIX_NONE,
756 cfhsi->rx_buf, CFHSI_DESC_SZ);
757 schedule_work(&cfhsi->out_of_sync_work);
758 }
759
760 static void cfhsi_rx_slowpath(unsigned long arg)
761 {
762 struct cfhsi *cfhsi = (struct cfhsi *)arg;
763
764 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
765 __func__);
766
767 cfhsi_rx_done(cfhsi);
768 }
769
770 static void cfhsi_rx_done_cb(struct cfhsi_drv *drv)
771 {
772 struct cfhsi *cfhsi;
773
774 cfhsi = container_of(drv, struct cfhsi, drv);
775 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
776 __func__);
777
778 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
779 return;
780
781 if (test_and_clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits))
782 wake_up_interruptible(&cfhsi->flush_fifo_wait);
783 else
784 cfhsi_rx_done(cfhsi);
785 }
786
787 static void cfhsi_wake_up(struct work_struct *work)
788 {
789 struct cfhsi *cfhsi = NULL;
790 int res;
791 int len;
792 long ret;
793
794 cfhsi = container_of(work, struct cfhsi, wake_up_work);
795
796 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
797 return;
798
799 if (unlikely(test_bit(CFHSI_AWAKE, &cfhsi->bits))) {
800 /* It happenes when wakeup is requested by
801 * both ends at the same time. */
802 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
803 clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
804 return;
805 }
806
807 /* Activate wake line. */
808 cfhsi->dev->cfhsi_wake_up(cfhsi->dev);
809
810 dev_dbg(&cfhsi->ndev->dev, "%s: Start waiting.\n",
811 __func__);
812
813 /* Wait for acknowledge. */
814 ret = CFHSI_WAKE_TOUT;
815 ret = wait_event_interruptible_timeout(cfhsi->wake_up_wait,
816 test_and_clear_bit(CFHSI_WAKE_UP_ACK,
817 &cfhsi->bits), ret);
818 if (unlikely(ret < 0)) {
819 /* Interrupted by signal. */
820 dev_err(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n",
821 __func__, ret);
822
823 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
824 cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
825 return;
826 } else if (!ret) {
827 bool ca_wake = false;
828 size_t fifo_occupancy = 0;
829
830 /* Wakeup timeout */
831 dev_dbg(&cfhsi->ndev->dev, "%s: Timeout.\n",
832 __func__);
833
834 /* Check FIFO to check if modem has sent something. */
835 WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
836 &fifo_occupancy));
837
838 dev_dbg(&cfhsi->ndev->dev, "%s: Bytes in FIFO: %u.\n",
839 __func__, (unsigned) fifo_occupancy);
840
841 /* Check if we misssed the interrupt. */
842 WARN_ON(cfhsi->dev->cfhsi_get_peer_wake(cfhsi->dev,
843 &ca_wake));
844
845 if (ca_wake) {
846 dev_err(&cfhsi->ndev->dev, "%s: CA Wake missed !.\n",
847 __func__);
848
849 /* Clear the CFHSI_WAKE_UP_ACK bit to prevent race. */
850 clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
851
852 /* Continue execution. */
853 goto wake_ack;
854 }
855
856 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
857 cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
858 return;
859 }
860 wake_ack:
861 dev_dbg(&cfhsi->ndev->dev, "%s: Woken.\n",
862 __func__);
863
864 /* Clear power up bit. */
865 set_bit(CFHSI_AWAKE, &cfhsi->bits);
866 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
867
868 /* Resume read operation. */
869 dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n", __func__);
870 res = cfhsi->dev->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->dev);
871
872 if (WARN_ON(res < 0))
873 dev_err(&cfhsi->ndev->dev, "%s: RX err %d.\n", __func__, res);
874
875 /* Clear power up acknowledment. */
876 clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
877
878 spin_lock_bh(&cfhsi->lock);
879
880 /* Resume transmit if queues are not empty. */
881 if (!cfhsi_tx_queue_len(cfhsi)) {
882 dev_dbg(&cfhsi->ndev->dev, "%s: Peer wake, start timer.\n",
883 __func__);
884 /* Start inactivity timer. */
885 mod_timer(&cfhsi->inactivity_timer,
886 jiffies + cfhsi->inactivity_timeout);
887 spin_unlock_bh(&cfhsi->lock);
888 return;
889 }
890
891 dev_dbg(&cfhsi->ndev->dev, "%s: Host wake.\n",
892 __func__);
893
894 spin_unlock_bh(&cfhsi->lock);
895
896 /* Create HSI frame. */
897 len = cfhsi_tx_frm((struct cfhsi_desc *)cfhsi->tx_buf, cfhsi);
898
899 if (likely(len > 0)) {
900 /* Set up new transfer. */
901 res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
902 if (WARN_ON(res < 0)) {
903 dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
904 __func__, res);
905 cfhsi_abort_tx(cfhsi);
906 }
907 } else {
908 dev_err(&cfhsi->ndev->dev,
909 "%s: Failed to create HSI frame: %d.\n",
910 __func__, len);
911 }
912 }
913
914 static void cfhsi_wake_down(struct work_struct *work)
915 {
916 long ret;
917 struct cfhsi *cfhsi = NULL;
918 size_t fifo_occupancy = 0;
919 int retry = CFHSI_WAKE_TOUT;
920
921 cfhsi = container_of(work, struct cfhsi, wake_down_work);
922 dev_dbg(&cfhsi->ndev->dev, "%s.\n", __func__);
923
924 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
925 return;
926
927 /* Deactivate wake line. */
928 cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
929
930 /* Wait for acknowledge. */
931 ret = CFHSI_WAKE_TOUT;
932 ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait,
933 test_and_clear_bit(CFHSI_WAKE_DOWN_ACK,
934 &cfhsi->bits), ret);
935 if (ret < 0) {
936 /* Interrupted by signal. */
937 dev_err(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n",
938 __func__, ret);
939 return;
940 } else if (!ret) {
941 bool ca_wake = true;
942
943 /* Timeout */
944 dev_err(&cfhsi->ndev->dev, "%s: Timeout.\n", __func__);
945
946 /* Check if we misssed the interrupt. */
947 WARN_ON(cfhsi->dev->cfhsi_get_peer_wake(cfhsi->dev,
948 &ca_wake));
949 if (!ca_wake)
950 dev_err(&cfhsi->ndev->dev, "%s: CA Wake missed !.\n",
951 __func__);
952 }
953
954 /* Check FIFO occupancy. */
955 while (retry) {
956 WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
957 &fifo_occupancy));
958
959 if (!fifo_occupancy)
960 break;
961
962 set_current_state(TASK_INTERRUPTIBLE);
963 schedule_timeout(1);
964 retry--;
965 }
966
967 if (!retry)
968 dev_err(&cfhsi->ndev->dev, "%s: FIFO Timeout.\n", __func__);
969
970 /* Clear AWAKE condition. */
971 clear_bit(CFHSI_AWAKE, &cfhsi->bits);
972
973 /* Cancel pending RX requests. */
974 cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev);
975
976 }
977
978 static void cfhsi_out_of_sync(struct work_struct *work)
979 {
980 struct cfhsi *cfhsi = NULL;
981
982 cfhsi = container_of(work, struct cfhsi, out_of_sync_work);
983
984 rtnl_lock();
985 dev_close(cfhsi->ndev);
986 rtnl_unlock();
987 }
988
989 static void cfhsi_wake_up_cb(struct cfhsi_drv *drv)
990 {
991 struct cfhsi *cfhsi = NULL;
992
993 cfhsi = container_of(drv, struct cfhsi, drv);
994 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
995 __func__);
996
997 set_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
998 wake_up_interruptible(&cfhsi->wake_up_wait);
999
1000 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
1001 return;
1002
1003 /* Schedule wake up work queue if the peer initiates. */
1004 if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
1005 queue_work(cfhsi->wq, &cfhsi->wake_up_work);
1006 }
1007
1008 static void cfhsi_wake_down_cb(struct cfhsi_drv *drv)
1009 {
1010 struct cfhsi *cfhsi = NULL;
1011
1012 cfhsi = container_of(drv, struct cfhsi, drv);
1013 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
1014 __func__);
1015
1016 /* Initiating low power is only permitted by the host (us). */
1017 set_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
1018 wake_up_interruptible(&cfhsi->wake_down_wait);
1019 }
1020
1021 static void cfhsi_aggregation_tout(unsigned long arg)
1022 {
1023 struct cfhsi *cfhsi = (struct cfhsi *)arg;
1024
1025 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
1026 __func__);
1027
1028 cfhsi_start_tx(cfhsi);
1029 }
1030
1031 static int cfhsi_xmit(struct sk_buff *skb, struct net_device *dev)
1032 {
1033 struct cfhsi *cfhsi = NULL;
1034 int start_xfer = 0;
1035 int timer_active;
1036 int prio;
1037
1038 if (!dev)
1039 return -EINVAL;
1040
1041 cfhsi = netdev_priv(dev);
1042
1043 switch (skb->priority) {
1044 case TC_PRIO_BESTEFFORT:
1045 case TC_PRIO_FILLER:
1046 case TC_PRIO_BULK:
1047 prio = CFHSI_PRIO_BEBK;
1048 break;
1049 case TC_PRIO_INTERACTIVE_BULK:
1050 prio = CFHSI_PRIO_VI;
1051 break;
1052 case TC_PRIO_INTERACTIVE:
1053 prio = CFHSI_PRIO_VO;
1054 break;
1055 case TC_PRIO_CONTROL:
1056 default:
1057 prio = CFHSI_PRIO_CTL;
1058 break;
1059 }
1060
1061 spin_lock_bh(&cfhsi->lock);
1062
1063 /* Update aggregation statistics */
1064 cfhsi_update_aggregation_stats(cfhsi, skb, 1);
1065
1066 /* Queue the SKB */
1067 skb_queue_tail(&cfhsi->qhead[prio], skb);
1068
1069 /* Sanity check; xmit should not be called after unregister_netdev */
1070 if (WARN_ON(test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))) {
1071 spin_unlock_bh(&cfhsi->lock);
1072 cfhsi_abort_tx(cfhsi);
1073 return -EINVAL;
1074 }
1075
1076 /* Send flow off if number of packets is above high water mark. */
1077 if (!cfhsi->flow_off_sent &&
1078 cfhsi_tx_queue_len(cfhsi) > cfhsi->q_high_mark &&
1079 cfhsi->cfdev.flowctrl) {
1080 cfhsi->flow_off_sent = 1;
1081 cfhsi->cfdev.flowctrl(cfhsi->ndev, OFF);
1082 }
1083
1084 if (cfhsi->tx_state == CFHSI_TX_STATE_IDLE) {
1085 cfhsi->tx_state = CFHSI_TX_STATE_XFER;
1086 start_xfer = 1;
1087 }
1088
1089 if (!start_xfer) {
1090 /* Send aggregate if it is possible */
1091 bool aggregate_ready =
1092 cfhsi_can_send_aggregate(cfhsi) &&
1093 del_timer(&cfhsi->aggregation_timer) > 0;
1094 spin_unlock_bh(&cfhsi->lock);
1095 if (aggregate_ready)
1096 cfhsi_start_tx(cfhsi);
1097 return 0;
1098 }
1099
1100 /* Delete inactivity timer if started. */
1101 timer_active = del_timer_sync(&cfhsi->inactivity_timer);
1102
1103 spin_unlock_bh(&cfhsi->lock);
1104
1105 if (timer_active) {
1106 struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
1107 int len;
1108 int res;
1109
1110 /* Create HSI frame. */
1111 len = cfhsi_tx_frm(desc, cfhsi);
1112 WARN_ON(!len);
1113
1114 /* Set up new transfer. */
1115 res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
1116 if (WARN_ON(res < 0)) {
1117 dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
1118 __func__, res);
1119 cfhsi_abort_tx(cfhsi);
1120 }
1121 } else {
1122 /* Schedule wake up work queue if the we initiate. */
1123 if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
1124 queue_work(cfhsi->wq, &cfhsi->wake_up_work);
1125 }
1126
1127 return 0;
1128 }
1129
1130 static int cfhsi_open(struct net_device *dev)
1131 {
1132 netif_wake_queue(dev);
1133
1134 return 0;
1135 }
1136
1137 static int cfhsi_close(struct net_device *dev)
1138 {
1139 netif_stop_queue(dev);
1140
1141 return 0;
1142 }
1143
1144 static const struct net_device_ops cfhsi_ops = {
1145 .ndo_open = cfhsi_open,
1146 .ndo_stop = cfhsi_close,
1147 .ndo_start_xmit = cfhsi_xmit
1148 };
1149
1150 static void cfhsi_setup(struct net_device *dev)
1151 {
1152 int i;
1153 struct cfhsi *cfhsi = netdev_priv(dev);
1154 dev->features = 0;
1155 dev->netdev_ops = &cfhsi_ops;
1156 dev->type = ARPHRD_CAIF;
1157 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
1158 dev->mtu = CFHSI_MAX_CAIF_FRAME_SZ;
1159 dev->tx_queue_len = 0;
1160 dev->destructor = free_netdev;
1161 for (i = 0; i < CFHSI_PRIO_LAST; ++i)
1162 skb_queue_head_init(&cfhsi->qhead[i]);
1163 cfhsi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
1164 cfhsi->cfdev.use_frag = false;
1165 cfhsi->cfdev.use_stx = false;
1166 cfhsi->cfdev.use_fcs = false;
1167 cfhsi->ndev = dev;
1168 }
1169
1170 int cfhsi_probe(struct platform_device *pdev)
1171 {
1172 struct cfhsi *cfhsi = NULL;
1173 struct net_device *ndev;
1174 struct cfhsi_dev *dev;
1175 int res;
1176
1177 ndev = alloc_netdev(sizeof(struct cfhsi), "cfhsi%d", cfhsi_setup);
1178 if (!ndev)
1179 return -ENODEV;
1180
1181 cfhsi = netdev_priv(ndev);
1182 cfhsi->ndev = ndev;
1183 cfhsi->pdev = pdev;
1184
1185 /* Initialize state vaiables. */
1186 cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
1187 cfhsi->rx_state.state = CFHSI_RX_STATE_DESC;
1188
1189 /* Set flow info */
1190 cfhsi->flow_off_sent = 0;
1191 cfhsi->q_low_mark = LOW_WATER_MARK;
1192 cfhsi->q_high_mark = HIGH_WATER_MARK;
1193
1194 /* Assign the HSI device. */
1195 dev = (struct cfhsi_dev *)pdev->dev.platform_data;
1196 cfhsi->dev = dev;
1197
1198 /* Assign the driver to this HSI device. */
1199 dev->drv = &cfhsi->drv;
1200
1201 /*
1202 * Allocate a TX buffer with the size of a HSI packet descriptors
1203 * and the necessary room for CAIF payload frames.
1204 */
1205 cfhsi->tx_buf = kzalloc(CFHSI_BUF_SZ_TX, GFP_KERNEL);
1206 if (!cfhsi->tx_buf) {
1207 res = -ENODEV;
1208 goto err_alloc_tx;
1209 }
1210
1211 /*
1212 * Allocate a RX buffer with the size of two HSI packet descriptors and
1213 * the necessary room for CAIF payload frames.
1214 */
1215 cfhsi->rx_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
1216 if (!cfhsi->rx_buf) {
1217 res = -ENODEV;
1218 goto err_alloc_rx;
1219 }
1220
1221 cfhsi->rx_flip_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
1222 if (!cfhsi->rx_flip_buf) {
1223 res = -ENODEV;
1224 goto err_alloc_rx_flip;
1225 }
1226
1227 /* Pre-calculate inactivity timeout. */
1228 if (inactivity_timeout != -1) {
1229 cfhsi->inactivity_timeout =
1230 inactivity_timeout * HZ / 1000;
1231 if (!cfhsi->inactivity_timeout)
1232 cfhsi->inactivity_timeout = 1;
1233 else if (cfhsi->inactivity_timeout > NEXT_TIMER_MAX_DELTA)
1234 cfhsi->inactivity_timeout = NEXT_TIMER_MAX_DELTA;
1235 } else {
1236 cfhsi->inactivity_timeout = NEXT_TIMER_MAX_DELTA;
1237 }
1238
1239 /* Initialize aggregation timeout */
1240 cfhsi->aggregation_timeout = aggregation_timeout;
1241
1242 /* Initialize recieve vaiables. */
1243 cfhsi->rx_ptr = cfhsi->rx_buf;
1244 cfhsi->rx_len = CFHSI_DESC_SZ;
1245
1246 /* Initialize spin locks. */
1247 spin_lock_init(&cfhsi->lock);
1248
1249 /* Set up the driver. */
1250 cfhsi->drv.tx_done_cb = cfhsi_tx_done_cb;
1251 cfhsi->drv.rx_done_cb = cfhsi_rx_done_cb;
1252 cfhsi->drv.wake_up_cb = cfhsi_wake_up_cb;
1253 cfhsi->drv.wake_down_cb = cfhsi_wake_down_cb;
1254
1255 /* Initialize the work queues. */
1256 INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up);
1257 INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down);
1258 INIT_WORK(&cfhsi->out_of_sync_work, cfhsi_out_of_sync);
1259
1260 /* Clear all bit fields. */
1261 clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
1262 clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
1263 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
1264 clear_bit(CFHSI_AWAKE, &cfhsi->bits);
1265
1266 /* Create work thread. */
1267 cfhsi->wq = create_singlethread_workqueue(pdev->name);
1268 if (!cfhsi->wq) {
1269 dev_err(&ndev->dev, "%s: Failed to create work queue.\n",
1270 __func__);
1271 res = -ENODEV;
1272 goto err_create_wq;
1273 }
1274
1275 /* Initialize wait queues. */
1276 init_waitqueue_head(&cfhsi->wake_up_wait);
1277 init_waitqueue_head(&cfhsi->wake_down_wait);
1278 init_waitqueue_head(&cfhsi->flush_fifo_wait);
1279
1280 /* Setup the inactivity timer. */
1281 init_timer(&cfhsi->inactivity_timer);
1282 cfhsi->inactivity_timer.data = (unsigned long)cfhsi;
1283 cfhsi->inactivity_timer.function = cfhsi_inactivity_tout;
1284 /* Setup the slowpath RX timer. */
1285 init_timer(&cfhsi->rx_slowpath_timer);
1286 cfhsi->rx_slowpath_timer.data = (unsigned long)cfhsi;
1287 cfhsi->rx_slowpath_timer.function = cfhsi_rx_slowpath;
1288 /* Setup the aggregation timer. */
1289 init_timer(&cfhsi->aggregation_timer);
1290 cfhsi->aggregation_timer.data = (unsigned long)cfhsi;
1291 cfhsi->aggregation_timer.function = cfhsi_aggregation_tout;
1292
1293 /* Add CAIF HSI device to list. */
1294 spin_lock(&cfhsi_list_lock);
1295 list_add_tail(&cfhsi->list, &cfhsi_list);
1296 spin_unlock(&cfhsi_list_lock);
1297
1298 /* Activate HSI interface. */
1299 res = cfhsi->dev->cfhsi_up(cfhsi->dev);
1300 if (res) {
1301 dev_err(&cfhsi->ndev->dev,
1302 "%s: can't activate HSI interface: %d.\n",
1303 __func__, res);
1304 goto err_activate;
1305 }
1306
1307 /* Flush FIFO */
1308 res = cfhsi_flush_fifo(cfhsi);
1309 if (res) {
1310 dev_err(&ndev->dev, "%s: Can't flush FIFO: %d.\n",
1311 __func__, res);
1312 goto err_net_reg;
1313 }
1314
1315 /* Register network device. */
1316 res = register_netdev(ndev);
1317 if (res) {
1318 dev_err(&ndev->dev, "%s: Registration error: %d.\n",
1319 __func__, res);
1320 goto err_net_reg;
1321 }
1322
1323 netif_stop_queue(ndev);
1324
1325 return res;
1326
1327 err_net_reg:
1328 cfhsi->dev->cfhsi_down(cfhsi->dev);
1329 err_activate:
1330 destroy_workqueue(cfhsi->wq);
1331 err_create_wq:
1332 kfree(cfhsi->rx_flip_buf);
1333 err_alloc_rx_flip:
1334 kfree(cfhsi->rx_buf);
1335 err_alloc_rx:
1336 kfree(cfhsi->tx_buf);
1337 err_alloc_tx:
1338 free_netdev(ndev);
1339
1340 return res;
1341 }
1342
1343 static void cfhsi_shutdown(struct cfhsi *cfhsi)
1344 {
1345 u8 *tx_buf, *rx_buf, *flip_buf;
1346
1347 /* Stop TXing */
1348 netif_tx_stop_all_queues(cfhsi->ndev);
1349
1350 /* going to shutdown driver */
1351 set_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
1352
1353 /* Flush workqueue */
1354 flush_workqueue(cfhsi->wq);
1355
1356 /* Delete timers if pending */
1357 del_timer_sync(&cfhsi->inactivity_timer);
1358 del_timer_sync(&cfhsi->rx_slowpath_timer);
1359 del_timer_sync(&cfhsi->aggregation_timer);
1360
1361 /* Cancel pending RX request (if any) */
1362 cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev);
1363
1364 /* Destroy workqueue */
1365 destroy_workqueue(cfhsi->wq);
1366
1367 /* Store bufferes: will be freed later. */
1368 tx_buf = cfhsi->tx_buf;
1369 rx_buf = cfhsi->rx_buf;
1370 flip_buf = cfhsi->rx_flip_buf;
1371 /* Flush transmit queues. */
1372 cfhsi_abort_tx(cfhsi);
1373
1374 /* Deactivate interface */
1375 cfhsi->dev->cfhsi_down(cfhsi->dev);
1376
1377 /* Finally unregister the network device. */
1378 unregister_netdev(cfhsi->ndev);
1379
1380 /* Free buffers. */
1381 kfree(tx_buf);
1382 kfree(rx_buf);
1383 kfree(flip_buf);
1384 }
1385
1386 int cfhsi_remove(struct platform_device *pdev)
1387 {
1388 struct list_head *list_node;
1389 struct list_head *n;
1390 struct cfhsi *cfhsi = NULL;
1391 struct cfhsi_dev *dev;
1392
1393 dev = (struct cfhsi_dev *)pdev->dev.platform_data;
1394 spin_lock(&cfhsi_list_lock);
1395 list_for_each_safe(list_node, n, &cfhsi_list) {
1396 cfhsi = list_entry(list_node, struct cfhsi, list);
1397 /* Find the corresponding device. */
1398 if (cfhsi->dev == dev) {
1399 /* Remove from list. */
1400 list_del(list_node);
1401 spin_unlock(&cfhsi_list_lock);
1402
1403 /* Shutdown driver. */
1404 cfhsi_shutdown(cfhsi);
1405
1406 return 0;
1407 }
1408 }
1409 spin_unlock(&cfhsi_list_lock);
1410 return -ENODEV;
1411 }
1412
1413 struct platform_driver cfhsi_plat_drv = {
1414 .probe = cfhsi_probe,
1415 .remove = cfhsi_remove,
1416 .driver = {
1417 .name = "cfhsi",
1418 .owner = THIS_MODULE,
1419 },
1420 };
1421
1422 static void __exit cfhsi_exit_module(void)
1423 {
1424 struct list_head *list_node;
1425 struct list_head *n;
1426 struct cfhsi *cfhsi = NULL;
1427
1428 spin_lock(&cfhsi_list_lock);
1429 list_for_each_safe(list_node, n, &cfhsi_list) {
1430 cfhsi = list_entry(list_node, struct cfhsi, list);
1431
1432 /* Remove from list. */
1433 list_del(list_node);
1434 spin_unlock(&cfhsi_list_lock);
1435
1436 /* Shutdown driver. */
1437 cfhsi_shutdown(cfhsi);
1438
1439 spin_lock(&cfhsi_list_lock);
1440 }
1441 spin_unlock(&cfhsi_list_lock);
1442
1443 /* Unregister platform driver. */
1444 platform_driver_unregister(&cfhsi_plat_drv);
1445 }
1446
1447 static int __init cfhsi_init_module(void)
1448 {
1449 int result;
1450
1451 /* Initialize spin lock. */
1452 spin_lock_init(&cfhsi_list_lock);
1453
1454 /* Register platform driver. */
1455 result = platform_driver_register(&cfhsi_plat_drv);
1456 if (result) {
1457 printk(KERN_ERR "Could not register platform HSI driver: %d.\n",
1458 result);
1459 goto err_dev_register;
1460 }
1461
1462 return result;
1463
1464 err_dev_register:
1465 return result;
1466 }
1467
1468 module_init(cfhsi_init_module);
1469 module_exit(cfhsi_exit_module);
Linux kernel - Deliverables
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