net: fix warning of versioncheck
[linux-2.6.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 <net/caif/caif_layer.h>
22 #include <net/caif/caif_hsi.h>
23
24 MODULE_LICENSE("GPL");
25 MODULE_AUTHOR("Daniel Martensson<daniel.martensson@stericsson.com>");
26 MODULE_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  */
36 static int hsi_head_align = 4;
37 module_param(hsi_head_align, int, S_IRUGO);
38 MODULE_PARM_DESC(hsi_head_align, "HSI head alignment.");
39
40 static int hsi_tail_align = 4;
41 module_param(hsi_tail_align, int, S_IRUGO);
42 MODULE_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  */
50 static int hsi_high_threshold = 100;
51 module_param(hsi_high_threshold, int, S_IRUGO);
52 MODULE_PARM_DESC(hsi_high_threshold, "HSI high threshold (FLOW OFF).");
53
54 static int hsi_low_threshold = 50;
55 module_param(hsi_low_threshold, int, S_IRUGO);
56 MODULE_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
69 static LIST_HEAD(cfhsi_list);
70 static spinlock_t cfhsi_list_lock;
71
72 static 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
84 static 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
105 static 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
170 static 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
274 static 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
324 static 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
338 static 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
412 drop_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
435 static 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
515 drop_frame:
516                 pfrm += *plen;
517                 rx_sz += *plen;
518                 plen++;
519                 nfrms++;
520         }
521
522         return rx_sz;
523 }
524
525 static 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
595 static 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
614 static 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
718 static 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
790 static 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
809 static 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
822 static 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
894 static int cfhsi_open(struct net_device *dev)
895 {
896         netif_wake_queue(dev);
897
898         return 0;
899 }
900
901 static int cfhsi_close(struct net_device *dev)
902 {
903         netif_stop_queue(dev);
904
905         return 0;
906 }
907
908 static 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
914 static 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
932 int 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
1084 static 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
1136 int 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
1163 struct 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
1172 static 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
1197 static 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
1218 module_init(cfhsi_init_module);
1219 module_exit(cfhsi_exit_module);