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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 <net/caif/caif_layer.h>
22#include <net/caif/caif_hsi.h>
23
24MODULE_LICENSE("GPL");
25MODULE_AUTHOR("Daniel Martensson<daniel.martensson@stericsson.com>");
26MODULE_DESCRIPTION("CAIF HSI driver");
27
28/* Returns the number of padding bytes for alignment. */
29#define PAD_POW2(x, pow) ((((x)&((pow)-1)) == 0) ? 0 :\
30 (((pow)-((x)&((pow)-1)))))
31
32/*
33 * HSI padding options.
34 * Warning: must be a base of 2 (& operation used) and can not be zero !
35 */
36static int hsi_head_align = 4;
37module_param(hsi_head_align, int, S_IRUGO);
38MODULE_PARM_DESC(hsi_head_align, "HSI head alignment.");
39
40static int hsi_tail_align = 4;
41module_param(hsi_tail_align, int, S_IRUGO);
42MODULE_PARM_DESC(hsi_tail_align, "HSI tail alignment.");
43
44/*
45 * HSI link layer flowcontrol thresholds.
46 * Warning: A high threshold value migth increase throughput but it will at
47 * the same time prevent channel prioritization and increase the risk of
48 * flooding the modem. The high threshold should be above the low.
49 */
50static int hsi_high_threshold = 100;
51module_param(hsi_high_threshold, int, S_IRUGO);
52MODULE_PARM_DESC(hsi_high_threshold, "HSI high threshold (FLOW OFF).");
53
54static int hsi_low_threshold = 50;
55module_param(hsi_low_threshold, int, S_IRUGO);
56MODULE_PARM_DESC(hsi_low_threshold, "HSI high threshold (FLOW ON).");
57
58#define ON 1
59#define OFF 0
60
61/*
62 * Threshold values for the HSI packet queue. Flowcontrol will be asserted
63 * when the number of packets exceeds HIGH_WATER_MARK. It will not be
64 * de-asserted before the number of packets drops below LOW_WATER_MARK.
65 */
66#define LOW_WATER_MARK hsi_low_threshold
67#define HIGH_WATER_MARK hsi_high_threshold
68
69static LIST_HEAD(cfhsi_list);
70static spinlock_t cfhsi_list_lock;
71
72static void cfhsi_inactivity_tout(unsigned long arg)
73{
74 struct cfhsi *cfhsi = (struct cfhsi *)arg;
75
76 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
77 __func__);
78
79 /* Schedule power down work queue. */
80 if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
81 queue_work(cfhsi->wq, &cfhsi->wake_down_work);
82}
83
84static void cfhsi_abort_tx(struct cfhsi *cfhsi)
85{
86 struct sk_buff *skb;
87
88 for (;;) {
89 spin_lock_bh(&cfhsi->lock);
90 skb = skb_dequeue(&cfhsi->qhead);
91 if (!skb)
92 break;
93
94 cfhsi->ndev->stats.tx_errors++;
95 cfhsi->ndev->stats.tx_dropped++;
96 spin_unlock_bh(&cfhsi->lock);
97 kfree_skb(skb);
98 }
99 cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
100 if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
101 mod_timer(&cfhsi->timer, jiffies + CFHSI_INACTIVITY_TOUT);
102 spin_unlock_bh(&cfhsi->lock);
103}
104
105static int cfhsi_flush_fifo(struct cfhsi *cfhsi)
106{
107 char buffer[32]; /* Any reasonable value */
108 size_t fifo_occupancy;
109 int ret;
110
111 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
112 __func__);
113
114
115 ret = cfhsi->dev->cfhsi_wake_up(cfhsi->dev);
116 if (ret) {
117 dev_warn(&cfhsi->ndev->dev,
118 "%s: can't wake up HSI interface: %d.\n",
119 __func__, ret);
120 return ret;
121 }
122
123 do {
124 ret = cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
125 &fifo_occupancy);
126 if (ret) {
127 dev_warn(&cfhsi->ndev->dev,
128 "%s: can't get FIFO occupancy: %d.\n",
129 __func__, ret);
130 break;
131 } else if (!fifo_occupancy)
132 /* No more data, exitting normally */
133 break;
134
135 fifo_occupancy = min(sizeof(buffer), fifo_occupancy);
136 set_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
137 ret = cfhsi->dev->cfhsi_rx(buffer, fifo_occupancy,
138 cfhsi->dev);
139 if (ret) {
140 clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
141 dev_warn(&cfhsi->ndev->dev,
142 "%s: can't read data: %d.\n",
143 __func__, ret);
144 break;
145 }
146
147 ret = 5 * HZ;
148 wait_event_interruptible_timeout(cfhsi->flush_fifo_wait,
149 !test_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits), ret);
150
151 if (ret < 0) {
152 dev_warn(&cfhsi->ndev->dev,
153 "%s: can't wait for flush complete: %d.\n",
154 __func__, ret);
155 break;
156 } else if (!ret) {
157 ret = -ETIMEDOUT;
158 dev_warn(&cfhsi->ndev->dev,
159 "%s: timeout waiting for flush complete.\n",
160 __func__);
161 break;
162 }
163 } while (1);
164
165 cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
166
167 return ret;
168}
169
170static int cfhsi_tx_frm(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
171{
172 int nfrms = 0;
173 int pld_len = 0;
174 struct sk_buff *skb;
175 u8 *pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
176
177 skb = skb_dequeue(&cfhsi->qhead);
178 if (!skb)
179 return 0;
180
181 /* Check if we can embed a CAIF frame. */
182 if (skb->len < CFHSI_MAX_EMB_FRM_SZ) {
183 struct caif_payload_info *info;
184 int hpad = 0;
185 int tpad = 0;
186
187 /* Calculate needed head alignment and tail alignment. */
188 info = (struct caif_payload_info *)&skb->cb;
189
190 hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
191 tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);
192
193 /* Check if frame still fits with added alignment. */
194 if ((skb->len + hpad + tpad) <= CFHSI_MAX_EMB_FRM_SZ) {
195 u8 *pemb = desc->emb_frm;
196 desc->offset = CFHSI_DESC_SHORT_SZ;
197 *pemb = (u8)(hpad - 1);
198 pemb += hpad;
199
200 /* Update network statistics. */
201 cfhsi->ndev->stats.tx_packets++;
202 cfhsi->ndev->stats.tx_bytes += skb->len;
203
204 /* Copy in embedded CAIF frame. */
205 skb_copy_bits(skb, 0, pemb, skb->len);
206 consume_skb(skb);
207 skb = NULL;
208 }
209 } else
210 /* Clear offset. */
211 desc->offset = 0;
212
213 /* Create payload CAIF frames. */
214 pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
215 while (nfrms < CFHSI_MAX_PKTS) {
216 struct caif_payload_info *info;
217 int hpad = 0;
218 int tpad = 0;
219
220 if (!skb)
221 skb = skb_dequeue(&cfhsi->qhead);
222
223 if (!skb)
224 break;
225
226 /* Calculate needed head alignment and tail alignment. */
227 info = (struct caif_payload_info *)&skb->cb;
228
229 hpad = 1 + PAD_POW2((info->hdr_len + 1), hsi_head_align);
230 tpad = PAD_POW2((skb->len + hpad), hsi_tail_align);
231
232 /* Fill in CAIF frame length in descriptor. */
233 desc->cffrm_len[nfrms] = hpad + skb->len + tpad;
234
235 /* Fill head padding information. */
236 *pfrm = (u8)(hpad - 1);
237 pfrm += hpad;
238
239 /* Update network statistics. */
240 cfhsi->ndev->stats.tx_packets++;
241 cfhsi->ndev->stats.tx_bytes += skb->len;
242
243 /* Copy in CAIF frame. */
244 skb_copy_bits(skb, 0, pfrm, skb->len);
245
246 /* Update payload length. */
247 pld_len += desc->cffrm_len[nfrms];
248
249 /* Update frame pointer. */
250 pfrm += skb->len + tpad;
251 consume_skb(skb);
252 skb = NULL;
253
254 /* Update number of frames. */
255 nfrms++;
256 }
257
258 /* Unused length fields should be zero-filled (according to SPEC). */
259 while (nfrms < CFHSI_MAX_PKTS) {
260 desc->cffrm_len[nfrms] = 0x0000;
261 nfrms++;
262 }
263
264 /* Check if we can piggy-back another descriptor. */
265 skb = skb_peek(&cfhsi->qhead);
266 if (skb)
267 desc->header |= CFHSI_PIGGY_DESC;
268 else
269 desc->header &= ~CFHSI_PIGGY_DESC;
270
271 return CFHSI_DESC_SZ + pld_len;
272}
273
274static void cfhsi_tx_done_work(struct work_struct *work)
275{
276 struct cfhsi *cfhsi = NULL;
277 struct cfhsi_desc *desc = NULL;
278 int len = 0;
279 int res;
280
281 cfhsi = container_of(work, struct cfhsi, tx_done_work);
282 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
283 __func__);
284
285 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
286 return;
287
288 desc = (struct cfhsi_desc *)cfhsi->tx_buf;
289
290 do {
291 /*
292 * Send flow on if flow off has been previously signalled
293 * and number of packets is below low water mark.
294 */
295 spin_lock_bh(&cfhsi->lock);
296 if (cfhsi->flow_off_sent &&
297 cfhsi->qhead.qlen <= cfhsi->q_low_mark &&
298 cfhsi->cfdev.flowctrl) {
299
300 cfhsi->flow_off_sent = 0;
301 cfhsi->cfdev.flowctrl(cfhsi->ndev, ON);
302 }
303 spin_unlock_bh(&cfhsi->lock);
304
305 /* Create HSI frame. */
306 len = cfhsi_tx_frm(desc, cfhsi);
307 if (!len) {
308 cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
309 /* Start inactivity timer. */
310 mod_timer(&cfhsi->timer,
311 jiffies + CFHSI_INACTIVITY_TOUT);
312 break;
313 }
314
315 /* Set up new transfer. */
316 res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
317 if (WARN_ON(res < 0)) {
318 dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
319 __func__, res);
320 }
321 } while (res < 0);
322}
323
324static void cfhsi_tx_done_cb(struct cfhsi_drv *drv)
325{
326 struct cfhsi *cfhsi;
327
328 cfhsi = container_of(drv, struct cfhsi, drv);
329 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
330 __func__);
331
332 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
333 return;
334
335 queue_work(cfhsi->wq, &cfhsi->tx_done_work);
336}
337
338static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
339{
340 int xfer_sz = 0;
341 int nfrms = 0;
342 u16 *plen = NULL;
343 u8 *pfrm = NULL;
344
345 if ((desc->header & ~CFHSI_PIGGY_DESC) ||
346 (desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
347 dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n",
348 __func__);
349 return 0;
350 }
351
352 /* Check for embedded CAIF frame. */
353 if (desc->offset) {
354 struct sk_buff *skb;
355 u8 *dst = NULL;
356 int len = 0, retries = 0;
357 pfrm = ((u8 *)desc) + desc->offset;
358
359 /* Remove offset padding. */
360 pfrm += *pfrm + 1;
361
362 /* Read length of CAIF frame (little endian). */
363 len = *pfrm;
364 len |= ((*(pfrm+1)) << 8) & 0xFF00;
365 len += 2; /* Add FCS fields. */
366
367
368 /* Allocate SKB (OK even in IRQ context). */
369 skb = alloc_skb(len + 1, GFP_KERNEL);
370 while (!skb) {
371 retries++;
372 schedule_timeout(1);
373 skb = alloc_skb(len + 1, GFP_KERNEL);
374 if (skb) {
375 printk(KERN_WARNING "%s: slept for %u "
376 "before getting memory\n",
377 __func__, retries);
378 break;
379 }
380 if (retries > HZ) {
381 printk(KERN_ERR "%s: slept for 1HZ and "
382 "did not get memory\n",
383 __func__);
384 cfhsi->ndev->stats.rx_dropped++;
385 goto drop_frame;
386 }
387 }
388 caif_assert(skb != NULL);
389
390 dst = skb_put(skb, len);
391 memcpy(dst, pfrm, len);
392
393 skb->protocol = htons(ETH_P_CAIF);
394 skb_reset_mac_header(skb);
395 skb->dev = cfhsi->ndev;
396
397 /*
398 * We are called from a arch specific platform device.
399 * Unfortunately we don't know what context we're
400 * running in.
401 */
402 if (in_interrupt())
403 netif_rx(skb);
404 else
405 netif_rx_ni(skb);
406
407 /* Update network statistics. */
408 cfhsi->ndev->stats.rx_packets++;
409 cfhsi->ndev->stats.rx_bytes += len;
410 }
411
412drop_frame:
413 /* Calculate transfer length. */
414 plen = desc->cffrm_len;
415 while (nfrms < CFHSI_MAX_PKTS && *plen) {
416 xfer_sz += *plen;
417 plen++;
418 nfrms++;
419 }
420
421 /* Check for piggy-backed descriptor. */
422 if (desc->header & CFHSI_PIGGY_DESC)
423 xfer_sz += CFHSI_DESC_SZ;
424
425 if (xfer_sz % 4) {
426 dev_err(&cfhsi->ndev->dev,
427 "%s: Invalid payload len: %d, ignored.\n",
428 __func__, xfer_sz);
429 xfer_sz = 0;
430 }
431
432 return xfer_sz;
433}
434
435static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
436{
437 int rx_sz = 0;
438 int nfrms = 0;
439 u16 *plen = NULL;
440 u8 *pfrm = NULL;
441
442 /* Sanity check header and offset. */
443 if (WARN_ON((desc->header & ~CFHSI_PIGGY_DESC) ||
444 (desc->offset > CFHSI_MAX_EMB_FRM_SZ))) {
445 dev_err(&cfhsi->ndev->dev, "%s: Invalid descriptor.\n",
446 __func__);
447 return -EINVAL;
448 }
449
450 /* Set frame pointer to start of payload. */
451 pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
452 plen = desc->cffrm_len;
453 while (nfrms < CFHSI_MAX_PKTS && *plen) {
454 struct sk_buff *skb;
455 u8 *dst = NULL;
456 u8 *pcffrm = NULL;
457 int len = 0, retries = 0;
458
459 if (WARN_ON(desc->cffrm_len[nfrms] > CFHSI_MAX_PAYLOAD_SZ)) {
460 dev_err(&cfhsi->ndev->dev, "%s: Invalid payload.\n",
461 __func__);
462 return -EINVAL;
463 }
464
465 /* CAIF frame starts after head padding. */
466 pcffrm = pfrm + *pfrm + 1;
467
468 /* Read length of CAIF frame (little endian). */
469 len = *pcffrm;
470 len |= ((*(pcffrm + 1)) << 8) & 0xFF00;
471 len += 2; /* Add FCS fields. */
472
473 /* Allocate SKB (OK even in IRQ context). */
474 skb = alloc_skb(len + 1, GFP_KERNEL);
475 while (!skb) {
476 retries++;
477 schedule_timeout(1);
478 skb = alloc_skb(len + 1, GFP_KERNEL);
479 if (skb) {
480 printk(KERN_WARNING "%s: slept for %u "
481 "before getting memory\n",
482 __func__, retries);
483 break;
484 }
485 if (retries > HZ) {
486 printk(KERN_ERR "%s: slept for 1HZ "
487 "and did not get memory\n",
488 __func__);
489 cfhsi->ndev->stats.rx_dropped++;
490 goto drop_frame;
491 }
492 }
493 caif_assert(skb != NULL);
494
495 dst = skb_put(skb, len);
496 memcpy(dst, pcffrm, len);
497
498 skb->protocol = htons(ETH_P_CAIF);
499 skb_reset_mac_header(skb);
500 skb->dev = cfhsi->ndev;
501
502 /*
503 * We're called from a platform device,
504 * and don't know the context we're running in.
505 */
506 if (in_interrupt())
507 netif_rx(skb);
508 else
509 netif_rx_ni(skb);
510
511 /* Update network statistics. */
512 cfhsi->ndev->stats.rx_packets++;
513 cfhsi->ndev->stats.rx_bytes += len;
514
515drop_frame:
516 pfrm += *plen;
517 rx_sz += *plen;
518 plen++;
519 nfrms++;
520 }
521
522 return rx_sz;
523}
524
525static void cfhsi_rx_done_work(struct work_struct *work)
526{
527 int res;
528 int desc_pld_len = 0;
529 struct cfhsi *cfhsi = NULL;
530 struct cfhsi_desc *desc = NULL;
531
532 cfhsi = container_of(work, struct cfhsi, rx_done_work);
533 desc = (struct cfhsi_desc *)cfhsi->rx_buf;
534
535 dev_dbg(&cfhsi->ndev->dev, "%s: Kick timer if pending.\n",
536 __func__);
537
538 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
539 return;
540
541 /* Update inactivity timer if pending. */
542 mod_timer_pending(&cfhsi->timer, jiffies + CFHSI_INACTIVITY_TOUT);
543
544 if (cfhsi->rx_state == CFHSI_RX_STATE_DESC) {
545 desc_pld_len = cfhsi_rx_desc(desc, cfhsi);
546 } else {
547 int pld_len;
548
549 pld_len = cfhsi_rx_pld(desc, cfhsi);
550
551 if ((pld_len > 0) && (desc->header & CFHSI_PIGGY_DESC)) {
552 struct cfhsi_desc *piggy_desc;
553 piggy_desc = (struct cfhsi_desc *)
554 (desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ +
555 pld_len);
556
557 /* Extract piggy-backed descriptor. */
558 desc_pld_len = cfhsi_rx_desc(piggy_desc, cfhsi);
559
560 /*
561 * Copy needed information from the piggy-backed
562 * descriptor to the descriptor in the start.
563 */
564 memcpy((u8 *)desc, (u8 *)piggy_desc,
565 CFHSI_DESC_SHORT_SZ);
566 }
567 }
568
569 if (desc_pld_len) {
570 cfhsi->rx_state = CFHSI_RX_STATE_PAYLOAD;
571 cfhsi->rx_ptr = cfhsi->rx_buf + CFHSI_DESC_SZ;
572 cfhsi->rx_len = desc_pld_len;
573 } else {
574 cfhsi->rx_state = CFHSI_RX_STATE_DESC;
575 cfhsi->rx_ptr = cfhsi->rx_buf;
576 cfhsi->rx_len = CFHSI_DESC_SZ;
577 }
578 clear_bit(CFHSI_PENDING_RX, &cfhsi->bits);
579
580 if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) {
581 /* Set up new transfer. */
582 dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n",
583 __func__);
584 res = cfhsi->dev->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len,
585 cfhsi->dev);
586 if (WARN_ON(res < 0)) {
587 dev_err(&cfhsi->ndev->dev, "%s: RX error %d.\n",
588 __func__, res);
589 cfhsi->ndev->stats.rx_errors++;
590 cfhsi->ndev->stats.rx_dropped++;
591 }
592 }
593}
594
595static void cfhsi_rx_done_cb(struct cfhsi_drv *drv)
596{
597 struct cfhsi *cfhsi;
598
599 cfhsi = container_of(drv, struct cfhsi, drv);
600 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
601 __func__);
602
603 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
604 return;
605
606 set_bit(CFHSI_PENDING_RX, &cfhsi->bits);
607
608 if (test_and_clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits))
609 wake_up_interruptible(&cfhsi->flush_fifo_wait);
610 else
611 queue_work(cfhsi->wq, &cfhsi->rx_done_work);
612}
613
614static void cfhsi_wake_up(struct work_struct *work)
615{
616 struct cfhsi *cfhsi = NULL;
617 int res;
618 int len;
619 long ret;
620
621 cfhsi = container_of(work, struct cfhsi, wake_up_work);
622
623 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
624 return;
625
626 if (unlikely(test_bit(CFHSI_AWAKE, &cfhsi->bits))) {
627 /* It happenes when wakeup is requested by
628 * both ends at the same time. */
629 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
630 return;
631 }
632
633 /* Activate wake line. */
634 cfhsi->dev->cfhsi_wake_up(cfhsi->dev);
635
636 dev_dbg(&cfhsi->ndev->dev, "%s: Start waiting.\n",
637 __func__);
638
639 /* Wait for acknowledge. */
640 ret = CFHSI_WAKEUP_TOUT;
641 wait_event_interruptible_timeout(cfhsi->wake_up_wait,
642 test_bit(CFHSI_WAKE_UP_ACK,
643 &cfhsi->bits), ret);
644 if (unlikely(ret < 0)) {
645 /* Interrupted by signal. */
646 dev_info(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n",
647 __func__, ret);
648 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
649 cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
650 return;
651 } else if (!ret) {
652 /* Wakeup timeout */
653 dev_err(&cfhsi->ndev->dev, "%s: Timeout.\n",
654 __func__);
655 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
656 cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
657 return;
658 }
659 dev_dbg(&cfhsi->ndev->dev, "%s: Woken.\n",
660 __func__);
661
662 /* Clear power up bit. */
663 set_bit(CFHSI_AWAKE, &cfhsi->bits);
664 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
665
666 /* Resume read operation. */
667 if (!test_bit(CFHSI_PENDING_RX, &cfhsi->bits)) {
668 dev_dbg(&cfhsi->ndev->dev, "%s: Start RX.\n",
669 __func__);
670 res = cfhsi->dev->cfhsi_rx(cfhsi->rx_ptr,
671 cfhsi->rx_len, cfhsi->dev);
672 if (WARN_ON(res < 0)) {
673 dev_err(&cfhsi->ndev->dev, "%s: RX error %d.\n",
674 __func__, res);
675 }
676 }
677
678 /* Clear power up acknowledment. */
679 clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
680
681 spin_lock_bh(&cfhsi->lock);
682
683 /* Resume transmit if queue is not empty. */
684 if (!skb_peek(&cfhsi->qhead)) {
685 dev_dbg(&cfhsi->ndev->dev, "%s: Peer wake, start timer.\n",
686 __func__);
687 /* Start inactivity timer. */
688 mod_timer(&cfhsi->timer,
689 jiffies + CFHSI_INACTIVITY_TOUT);
690 spin_unlock_bh(&cfhsi->lock);
691 return;
692 }
693
694 dev_dbg(&cfhsi->ndev->dev, "%s: Host wake.\n",
695 __func__);
696
697 spin_unlock_bh(&cfhsi->lock);
698
699 /* Create HSI frame. */
700 len = cfhsi_tx_frm((struct cfhsi_desc *)cfhsi->tx_buf, cfhsi);
701
702 if (likely(len > 0)) {
703 /* Set up new transfer. */
704 res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
705 if (WARN_ON(res < 0)) {
706 dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
707 __func__, res);
708 cfhsi_abort_tx(cfhsi);
709 }
710 } else {
711 dev_err(&cfhsi->ndev->dev,
712 "%s: Failed to create HSI frame: %d.\n",
713 __func__, len);
714 }
715
716}
717
718static void cfhsi_wake_down(struct work_struct *work)
719{
720 long ret;
721 struct cfhsi *cfhsi = NULL;
722 size_t fifo_occupancy;
723
724 cfhsi = container_of(work, struct cfhsi, wake_down_work);
725 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
726 __func__);
727
728 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
729 return;
730
731 /* Check if there is something in FIFO. */
732 if (WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
733 &fifo_occupancy)))
734 fifo_occupancy = 0;
735
736 if (fifo_occupancy) {
737 dev_dbg(&cfhsi->ndev->dev,
738 "%s: %u words in RX FIFO, restart timer.\n",
739 __func__, (unsigned) fifo_occupancy);
740 spin_lock_bh(&cfhsi->lock);
741 mod_timer(&cfhsi->timer,
742 jiffies + CFHSI_INACTIVITY_TOUT);
743 spin_unlock_bh(&cfhsi->lock);
744 return;
745 }
746
747 /* Cancel pending RX requests */
748 cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev);
749
750 /* Deactivate wake line. */
751 cfhsi->dev->cfhsi_wake_down(cfhsi->dev);
752
753 /* Wait for acknowledge. */
754 ret = CFHSI_WAKEUP_TOUT;
755 ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait,
756 test_bit(CFHSI_WAKE_DOWN_ACK,
757 &cfhsi->bits),
758 ret);
759 if (ret < 0) {
760 /* Interrupted by signal. */
761 dev_info(&cfhsi->ndev->dev, "%s: Signalled: %ld.\n",
762 __func__, ret);
763 return;
764 } else if (!ret) {
765 /* Timeout */
766 dev_err(&cfhsi->ndev->dev, "%s: Timeout.\n",
767 __func__);
768 }
769
770 /* Clear power down acknowledment. */
771 clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
772 clear_bit(CFHSI_AWAKE, &cfhsi->bits);
773
774 /* Check if there is something in FIFO. */
775 if (WARN_ON(cfhsi->dev->cfhsi_fifo_occupancy(cfhsi->dev,
776 &fifo_occupancy)))
777 fifo_occupancy = 0;
778
779 if (fifo_occupancy) {
780 dev_dbg(&cfhsi->ndev->dev,
781 "%s: %u words in RX FIFO, wakeup forced.\n",
782 __func__, (unsigned) fifo_occupancy);
783 if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
784 queue_work(cfhsi->wq, &cfhsi->wake_up_work);
785 } else
786 dev_dbg(&cfhsi->ndev->dev, "%s: Done.\n",
787 __func__);
788}
789
790static void cfhsi_wake_up_cb(struct cfhsi_drv *drv)
791{
792 struct cfhsi *cfhsi = NULL;
793
794 cfhsi = container_of(drv, struct cfhsi, drv);
795 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
796 __func__);
797
798 set_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
799 wake_up_interruptible(&cfhsi->wake_up_wait);
800
801 if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
802 return;
803
804 /* Schedule wake up work queue if the peer initiates. */
805 if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
806 queue_work(cfhsi->wq, &cfhsi->wake_up_work);
807}
808
809static void cfhsi_wake_down_cb(struct cfhsi_drv *drv)
810{
811 struct cfhsi *cfhsi = NULL;
812
813 cfhsi = container_of(drv, struct cfhsi, drv);
814 dev_dbg(&cfhsi->ndev->dev, "%s.\n",
815 __func__);
816
817 /* Initiating low power is only permitted by the host (us). */
818 set_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
819 wake_up_interruptible(&cfhsi->wake_down_wait);
820}
821
822static int cfhsi_xmit(struct sk_buff *skb, struct net_device *dev)
823{
824 struct cfhsi *cfhsi = NULL;
825 int start_xfer = 0;
826 int timer_active;
827
828 if (!dev)
829 return -EINVAL;
830
831 cfhsi = netdev_priv(dev);
832
833 spin_lock_bh(&cfhsi->lock);
834
835 skb_queue_tail(&cfhsi->qhead, skb);
836
837 /* Sanity check; xmit should not be called after unregister_netdev */
838 if (WARN_ON(test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))) {
839 spin_unlock_bh(&cfhsi->lock);
840 cfhsi_abort_tx(cfhsi);
841 return -EINVAL;
842 }
843
844 /* Send flow off if number of packets is above high water mark. */
845 if (!cfhsi->flow_off_sent &&
846 cfhsi->qhead.qlen > cfhsi->q_high_mark &&
847 cfhsi->cfdev.flowctrl) {
848 cfhsi->flow_off_sent = 1;
849 cfhsi->cfdev.flowctrl(cfhsi->ndev, OFF);
850 }
851
852 if (cfhsi->tx_state == CFHSI_TX_STATE_IDLE) {
853 cfhsi->tx_state = CFHSI_TX_STATE_XFER;
854 start_xfer = 1;
855 }
856
857 spin_unlock_bh(&cfhsi->lock);
858
859 if (!start_xfer)
860 return 0;
861
862 /* Delete inactivity timer if started. */
863#ifdef CONFIG_SMP
864 timer_active = del_timer_sync(&cfhsi->timer);
865#else
866 timer_active = del_timer(&cfhsi->timer);
867#endif /* CONFIG_SMP */
868
869 if (timer_active) {
870 struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
871 int len;
872 int res;
873
874 /* Create HSI frame. */
875 len = cfhsi_tx_frm(desc, cfhsi);
876 BUG_ON(!len);
877
878 /* Set up new transfer. */
879 res = cfhsi->dev->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->dev);
880 if (WARN_ON(res < 0)) {
881 dev_err(&cfhsi->ndev->dev, "%s: TX error %d.\n",
882 __func__, res);
883 cfhsi_abort_tx(cfhsi);
884 }
885 } else {
886 /* Schedule wake up work queue if the we initiate. */
887 if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
888 queue_work(cfhsi->wq, &cfhsi->wake_up_work);
889 }
890
891 return 0;
892}
893
894static int cfhsi_open(struct net_device *dev)
895{
896 netif_wake_queue(dev);
897
898 return 0;
899}
900
901static int cfhsi_close(struct net_device *dev)
902{
903 netif_stop_queue(dev);
904
905 return 0;
906}
907
908static const struct net_device_ops cfhsi_ops = {
909 .ndo_open = cfhsi_open,
910 .ndo_stop = cfhsi_close,
911 .ndo_start_xmit = cfhsi_xmit
912};
913
914static void cfhsi_setup(struct net_device *dev)
915{
916 struct cfhsi *cfhsi = netdev_priv(dev);
917 dev->features = 0;
918 dev->netdev_ops = &cfhsi_ops;
919 dev->type = ARPHRD_CAIF;
920 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
921 dev->mtu = CFHSI_MAX_PAYLOAD_SZ;
922 dev->tx_queue_len = 0;
923 dev->destructor = free_netdev;
924 skb_queue_head_init(&cfhsi->qhead);
925 cfhsi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
926 cfhsi->cfdev.use_frag = false;
927 cfhsi->cfdev.use_stx = false;
928 cfhsi->cfdev.use_fcs = false;
929 cfhsi->ndev = dev;
930}
931
932int cfhsi_probe(struct platform_device *pdev)
933{
934 struct cfhsi *cfhsi = NULL;
935 struct net_device *ndev;
936 struct cfhsi_dev *dev;
937 int res;
938
939 ndev = alloc_netdev(sizeof(struct cfhsi), "cfhsi%d", cfhsi_setup);
940 if (!ndev) {
941 dev_err(&pdev->dev, "%s: alloc_netdev failed.\n",
942 __func__);
943 return -ENODEV;
944 }
945
946 cfhsi = netdev_priv(ndev);
947 cfhsi->ndev = ndev;
948 cfhsi->pdev = pdev;
949
950 /* Initialize state vaiables. */
951 cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
952 cfhsi->rx_state = CFHSI_RX_STATE_DESC;
953
954 /* Set flow info */
955 cfhsi->flow_off_sent = 0;
956 cfhsi->q_low_mark = LOW_WATER_MARK;
957 cfhsi->q_high_mark = HIGH_WATER_MARK;
958
959 /* Assign the HSI device. */
960 dev = (struct cfhsi_dev *)pdev->dev.platform_data;
961 cfhsi->dev = dev;
962
963 /* Assign the driver to this HSI device. */
964 dev->drv = &cfhsi->drv;
965
966 /*
967 * Allocate a TX buffer with the size of a HSI packet descriptors
968 * and the necessary room for CAIF payload frames.
969 */
970 cfhsi->tx_buf = kzalloc(CFHSI_BUF_SZ_TX, GFP_KERNEL);
971 if (!cfhsi->tx_buf) {
972 dev_err(&ndev->dev, "%s: Failed to allocate TX buffer.\n",
973 __func__);
974 res = -ENODEV;
975 goto err_alloc_tx;
976 }
977
978 /*
979 * Allocate a RX buffer with the size of two HSI packet descriptors and
980 * the necessary room for CAIF payload frames.
981 */
982 cfhsi->rx_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
983 if (!cfhsi->rx_buf) {
984 dev_err(&ndev->dev, "%s: Failed to allocate RX buffer.\n",
985 __func__);
986 res = -ENODEV;
987 goto err_alloc_rx;
988 }
989
990 /* Initialize receive variables. */
991 cfhsi->rx_ptr = cfhsi->rx_buf;
992 cfhsi->rx_len = CFHSI_DESC_SZ;
993
994 /* Initialize spin locks. */
995 spin_lock_init(&cfhsi->lock);
996
997 /* Set up the driver. */
998 cfhsi->drv.tx_done_cb = cfhsi_tx_done_cb;
999 cfhsi->drv.rx_done_cb = cfhsi_rx_done_cb;
1000
1001 /* Initialize the work queues. */
1002 INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up);
1003 INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down);
1004 INIT_WORK(&cfhsi->rx_done_work, cfhsi_rx_done_work);
1005 INIT_WORK(&cfhsi->tx_done_work, cfhsi_tx_done_work);
1006
1007 /* Clear all bit fields. */
1008 clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
1009 clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
1010 clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
1011 clear_bit(CFHSI_AWAKE, &cfhsi->bits);
1012 clear_bit(CFHSI_PENDING_RX, &cfhsi->bits);
1013
1014 /* Create work thread. */
1015 cfhsi->wq = create_singlethread_workqueue(pdev->name);
1016 if (!cfhsi->wq) {
1017 dev_err(&ndev->dev, "%s: Failed to create work queue.\n",
1018 __func__);
1019 res = -ENODEV;
1020 goto err_create_wq;
1021 }
1022
1023 /* Initialize wait queues. */
1024 init_waitqueue_head(&cfhsi->wake_up_wait);
1025 init_waitqueue_head(&cfhsi->wake_down_wait);
1026 init_waitqueue_head(&cfhsi->flush_fifo_wait);
1027
1028 /* Setup the inactivity timer. */
1029 init_timer(&cfhsi->timer);
1030 cfhsi->timer.data = (unsigned long)cfhsi;
1031 cfhsi->timer.function = cfhsi_inactivity_tout;
1032
1033 /* Add CAIF HSI device to list. */
1034 spin_lock(&cfhsi_list_lock);
1035 list_add_tail(&cfhsi->list, &cfhsi_list);
1036 spin_unlock(&cfhsi_list_lock);
1037
1038 /* Activate HSI interface. */
1039 res = cfhsi->dev->cfhsi_up(cfhsi->dev);
1040 if (res) {
1041 dev_err(&cfhsi->ndev->dev,
1042 "%s: can't activate HSI interface: %d.\n",
1043 __func__, res);
1044 goto err_activate;
1045 }
1046
1047 /* Flush FIFO */
1048 res = cfhsi_flush_fifo(cfhsi);
1049 if (res) {
1050 dev_err(&ndev->dev, "%s: Can't flush FIFO: %d.\n",
1051 __func__, res);
1052 goto err_net_reg;
1053 }
1054
1055 cfhsi->drv.wake_up_cb = cfhsi_wake_up_cb;
1056 cfhsi->drv.wake_down_cb = cfhsi_wake_down_cb;
1057
1058 /* Register network device. */
1059 res = register_netdev(ndev);
1060 if (res) {
1061 dev_err(&ndev->dev, "%s: Registration error: %d.\n",
1062 __func__, res);
1063 goto err_net_reg;
1064 }
1065
1066 netif_stop_queue(ndev);
1067
1068 return res;
1069
1070 err_net_reg:
1071 cfhsi->dev->cfhsi_down(cfhsi->dev);
1072 err_activate:
1073 destroy_workqueue(cfhsi->wq);
1074 err_create_wq:
1075 kfree(cfhsi->rx_buf);
1076 err_alloc_rx:
1077 kfree(cfhsi->tx_buf);
1078 err_alloc_tx:
1079 free_netdev(ndev);
1080
1081 return res;
1082}
1083
1084static void cfhsi_shutdown(struct cfhsi *cfhsi, bool remove_platform_dev)
1085{
1086 u8 *tx_buf, *rx_buf;
1087
1088 /* Stop TXing */
1089 netif_tx_stop_all_queues(cfhsi->ndev);
1090
1091 /* going to shutdown driver */
1092 set_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
1093
1094 if (remove_platform_dev) {
1095 /* Flush workqueue */
1096 flush_workqueue(cfhsi->wq);
1097
1098 /* Notify device. */
1099 platform_device_unregister(cfhsi->pdev);
1100 }
1101
1102 /* Flush workqueue */
1103 flush_workqueue(cfhsi->wq);
1104
1105 /* Delete timer if pending */
1106#ifdef CONFIG_SMP
1107 del_timer_sync(&cfhsi->timer);
1108#else
1109 del_timer(&cfhsi->timer);
1110#endif /* CONFIG_SMP */
1111
1112 /* Cancel pending RX request (if any) */
1113 cfhsi->dev->cfhsi_rx_cancel(cfhsi->dev);
1114
1115 /* Flush again and destroy workqueue */
1116 destroy_workqueue(cfhsi->wq);
1117
1118 /* Store bufferes: will be freed later. */
1119 tx_buf = cfhsi->tx_buf;
1120 rx_buf = cfhsi->rx_buf;
1121
1122 /* Flush transmit queues. */
1123 cfhsi_abort_tx(cfhsi);
1124
1125 /* Deactivate interface */
1126 cfhsi->dev->cfhsi_down(cfhsi->dev);
1127
1128 /* Finally unregister the network device. */
1129 unregister_netdev(cfhsi->ndev);
1130
1131 /* Free buffers. */
1132 kfree(tx_buf);
1133 kfree(rx_buf);
1134}
1135
1136int cfhsi_remove(struct platform_device *pdev)
1137{
1138 struct list_head *list_node;
1139 struct list_head *n;
1140 struct cfhsi *cfhsi = NULL;
1141 struct cfhsi_dev *dev;
1142
1143 dev = (struct cfhsi_dev *)pdev->dev.platform_data;
1144 spin_lock(&cfhsi_list_lock);
1145 list_for_each_safe(list_node, n, &cfhsi_list) {
1146 cfhsi = list_entry(list_node, struct cfhsi, list);
1147 /* Find the corresponding device. */
1148 if (cfhsi->dev == dev) {
1149 /* Remove from list. */
1150 list_del(list_node);
1151 spin_unlock(&cfhsi_list_lock);
1152
1153 /* Shutdown driver. */
1154 cfhsi_shutdown(cfhsi, false);
1155
1156 return 0;
1157 }
1158 }
1159 spin_unlock(&cfhsi_list_lock);
1160 return -ENODEV;
1161}
1162
1163struct platform_driver cfhsi_plat_drv = {
1164 .probe = cfhsi_probe,
1165 .remove = cfhsi_remove,
1166 .driver = {
1167 .name = "cfhsi",
1168 .owner = THIS_MODULE,
1169 },
1170};
1171
1172static void __exit cfhsi_exit_module(void)
1173{
1174 struct list_head *list_node;
1175 struct list_head *n;
1176 struct cfhsi *cfhsi = NULL;
1177
1178 spin_lock(&cfhsi_list_lock);
1179 list_for_each_safe(list_node, n, &cfhsi_list) {
1180 cfhsi = list_entry(list_node, struct cfhsi, list);
1181
1182 /* Remove from list. */
1183 list_del(list_node);
1184 spin_unlock(&cfhsi_list_lock);
1185
1186 /* Shutdown driver. */
1187 cfhsi_shutdown(cfhsi, true);
1188
1189 spin_lock(&cfhsi_list_lock);
1190 }
1191 spin_unlock(&cfhsi_list_lock);
1192
1193 /* Unregister platform driver. */
1194 platform_driver_unregister(&cfhsi_plat_drv);
1195}
1196
1197static int __init cfhsi_init_module(void)
1198{
1199 int result;
1200
1201 /* Initialize spin lock. */
1202 spin_lock_init(&cfhsi_list_lock);
1203
1204 /* Register platform driver. */
1205 result = platform_driver_register(&cfhsi_plat_drv);
1206 if (result) {
1207 printk(KERN_ERR "Could not register platform HSI driver: %d.\n",
1208 result);
1209 goto err_dev_register;
1210 }
1211
1212 return result;
1213
1214 err_dev_register:
1215 return result;
1216}
1217
1218module_init(cfhsi_init_module);
1219module_exit(cfhsi_exit_module);