Merge branch 'for_paulus' of git://git.kernel.org/pub/scm/linux/kernel/git/galak...
[linux-2.6] / drivers / net / wireless / bcm43xx / bcm43xx_pio.c
1 /*
2
3   Broadcom BCM43xx wireless driver
4
5   PIO Transmission
6
7   Copyright (c) 2005 Michael Buesch <mbuesch@freenet.de>
8
9   This program is free software; you can redistribute it and/or modify
10   it under the terms of the GNU General Public License as published by
11   the Free Software Foundation; either version 2 of the License, or
12   (at your option) any later version.
13
14   This program is distributed in the hope that it will be useful,
15   but WITHOUT ANY WARRANTY; without even the implied warranty of
16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17   GNU General Public License for more details.
18
19   You should have received a copy of the GNU General Public License
20   along with this program; see the file COPYING.  If not, write to
21   the Free Software Foundation, Inc., 51 Franklin Steet, Fifth Floor,
22   Boston, MA 02110-1301, USA.
23
24 */
25
26 #include "bcm43xx.h"
27 #include "bcm43xx_pio.h"
28 #include "bcm43xx_main.h"
29 #include "bcm43xx_xmit.h"
30
31 #include <linux/delay.h>
32
33
34 static void tx_start(struct bcm43xx_pioqueue *queue)
35 {
36         bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
37                           BCM43xx_PIO_TXCTL_INIT);
38 }
39
40 static void tx_octet(struct bcm43xx_pioqueue *queue,
41                      u8 octet)
42 {
43         if (queue->need_workarounds) {
44                 bcm43xx_pio_write(queue, BCM43xx_PIO_TXDATA,
45                                   octet);
46                 bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
47                                   BCM43xx_PIO_TXCTL_WRITEHI);
48         } else {
49                 bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
50                                   BCM43xx_PIO_TXCTL_WRITEHI);
51                 bcm43xx_pio_write(queue, BCM43xx_PIO_TXDATA,
52                                   octet);
53         }
54 }
55
56 static u16 tx_get_next_word(struct bcm43xx_txhdr *txhdr,
57                             const u8 *packet,
58                             unsigned int *pos)
59 {
60         const u8 *source;
61         unsigned int i = *pos;
62         u16 ret;
63
64         if (i < sizeof(*txhdr)) {
65                 source = (const u8 *)txhdr;
66         } else {
67                 source = packet;
68                 i -= sizeof(*txhdr);
69         }
70         ret = le16_to_cpu( *((u16 *)(source + i)) );
71         *pos += 2;
72
73         return ret;
74 }
75
76 static void tx_data(struct bcm43xx_pioqueue *queue,
77                     struct bcm43xx_txhdr *txhdr,
78                     const u8 *packet,
79                     unsigned int octets)
80 {
81         u16 data;
82         unsigned int i = 0;
83
84         if (queue->need_workarounds) {
85                 data = tx_get_next_word(txhdr, packet, &i);
86                 bcm43xx_pio_write(queue, BCM43xx_PIO_TXDATA, data);
87         }
88         bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
89                           BCM43xx_PIO_TXCTL_WRITELO |
90                           BCM43xx_PIO_TXCTL_WRITEHI);
91         while (i < octets - 1) {
92                 data = tx_get_next_word(txhdr, packet, &i);
93                 bcm43xx_pio_write(queue, BCM43xx_PIO_TXDATA, data);
94         }
95         if (octets % 2)
96                 tx_octet(queue, packet[octets - sizeof(*txhdr) - 1]);
97 }
98
99 static void tx_complete(struct bcm43xx_pioqueue *queue,
100                         struct sk_buff *skb)
101 {
102         if (queue->need_workarounds) {
103                 bcm43xx_pio_write(queue, BCM43xx_PIO_TXDATA,
104                                   skb->data[skb->len - 1]);
105                 bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
106                                   BCM43xx_PIO_TXCTL_WRITEHI |
107                                   BCM43xx_PIO_TXCTL_COMPLETE);
108         } else {
109                 bcm43xx_pio_write(queue, BCM43xx_PIO_TXCTL,
110                                   BCM43xx_PIO_TXCTL_COMPLETE);
111         }
112 }
113
114 static u16 generate_cookie(struct bcm43xx_pioqueue *queue,
115                            int packetindex)
116 {
117         u16 cookie = 0x0000;
118
119         /* We use the upper 4 bits for the PIO
120          * controller ID and the lower 12 bits
121          * for the packet index (in the cache).
122          */
123         switch (queue->mmio_base) {
124         case BCM43xx_MMIO_PIO1_BASE:
125                 break;
126         case BCM43xx_MMIO_PIO2_BASE:
127                 cookie = 0x1000;
128                 break;
129         case BCM43xx_MMIO_PIO3_BASE:
130                 cookie = 0x2000;
131                 break;
132         case BCM43xx_MMIO_PIO4_BASE:
133                 cookie = 0x3000;
134                 break;
135         default:
136                 assert(0);
137         }
138         assert(((u16)packetindex & 0xF000) == 0x0000);
139         cookie |= (u16)packetindex;
140
141         return cookie;
142 }
143
144 static
145 struct bcm43xx_pioqueue * parse_cookie(struct bcm43xx_private *bcm,
146                                        u16 cookie,
147                                        struct bcm43xx_pio_txpacket **packet)
148 {
149         struct bcm43xx_pio *pio = bcm43xx_current_pio(bcm);
150         struct bcm43xx_pioqueue *queue = NULL;
151         int packetindex;
152
153         switch (cookie & 0xF000) {
154         case 0x0000:
155                 queue = pio->queue0;
156                 break;
157         case 0x1000:
158                 queue = pio->queue1;
159                 break;
160         case 0x2000:
161                 queue = pio->queue2;
162                 break;
163         case 0x3000:
164                 queue = pio->queue3;
165                 break;
166         default:
167                 assert(0);
168         }
169         packetindex = (cookie & 0x0FFF);
170         assert(packetindex >= 0 && packetindex < BCM43xx_PIO_MAXTXPACKETS);
171         *packet = &(queue->tx_packets_cache[packetindex]);
172
173         return queue;
174 }
175
176 static void pio_tx_write_fragment(struct bcm43xx_pioqueue *queue,
177                                   struct sk_buff *skb,
178                                   struct bcm43xx_pio_txpacket *packet)
179 {
180         struct bcm43xx_txhdr txhdr;
181         unsigned int octets;
182
183         assert(skb_shinfo(skb)->nr_frags == 0);
184         bcm43xx_generate_txhdr(queue->bcm,
185                                &txhdr, skb->data, skb->len,
186                                (packet->xmitted_frags == 0),
187                                generate_cookie(queue, pio_txpacket_getindex(packet)));
188
189         tx_start(queue);
190         octets = skb->len + sizeof(txhdr);
191         if (queue->need_workarounds)
192                 octets--;
193         tx_data(queue, &txhdr, (u8 *)skb->data, octets);
194         tx_complete(queue, skb);
195 }
196
197 static void free_txpacket(struct bcm43xx_pio_txpacket *packet,
198                           int irq_context)
199 {
200         struct bcm43xx_pioqueue *queue = packet->queue;
201
202         ieee80211_txb_free(packet->txb);
203         list_move(&packet->list, &queue->txfree);
204         queue->nr_txfree++;
205
206         assert(queue->tx_devq_used >= packet->xmitted_octets);
207         assert(queue->tx_devq_packets >= packet->xmitted_frags);
208         queue->tx_devq_used -= packet->xmitted_octets;
209         queue->tx_devq_packets -= packet->xmitted_frags;
210 }
211
212 static int pio_tx_packet(struct bcm43xx_pio_txpacket *packet)
213 {
214         struct bcm43xx_pioqueue *queue = packet->queue;
215         struct ieee80211_txb *txb = packet->txb;
216         struct sk_buff *skb;
217         u16 octets;
218         int i;
219
220         for (i = packet->xmitted_frags; i < txb->nr_frags; i++) {
221                 skb = txb->fragments[i];
222
223                 octets = (u16)skb->len + sizeof(struct bcm43xx_txhdr);
224                 assert(queue->tx_devq_size >= octets);
225                 assert(queue->tx_devq_packets <= BCM43xx_PIO_MAXTXDEVQPACKETS);
226                 assert(queue->tx_devq_used <= queue->tx_devq_size);
227                 /* Check if there is sufficient free space on the device
228                  * TX queue. If not, return and let the TX tasklet
229                  * retry later.
230                  */
231                 if (queue->tx_devq_packets == BCM43xx_PIO_MAXTXDEVQPACKETS)
232                         return -EBUSY;
233                 if (queue->tx_devq_used + octets > queue->tx_devq_size)
234                         return -EBUSY;
235                 /* Now poke the device. */
236                 pio_tx_write_fragment(queue, skb, packet);
237
238                 /* Account for the packet size.
239                  * (We must not overflow the device TX queue)
240                  */
241                 queue->tx_devq_packets++;
242                 queue->tx_devq_used += octets;
243
244                 assert(packet->xmitted_frags <= packet->txb->nr_frags);
245                 packet->xmitted_frags++;
246                 packet->xmitted_octets += octets;
247         }
248         list_move_tail(&packet->list, &queue->txrunning);
249
250         return 0;
251 }
252
253 static void tx_tasklet(unsigned long d)
254 {
255         struct bcm43xx_pioqueue *queue = (struct bcm43xx_pioqueue *)d;
256         struct bcm43xx_private *bcm = queue->bcm;
257         unsigned long flags;
258         struct bcm43xx_pio_txpacket *packet, *tmp_packet;
259         int err;
260
261         bcm43xx_lock_mmio(bcm, flags);
262         list_for_each_entry_safe(packet, tmp_packet, &queue->txqueue, list) {
263                 assert(packet->xmitted_frags < packet->txb->nr_frags);
264                 if (packet->xmitted_frags == 0) {
265                         int i;
266                         struct sk_buff *skb;
267
268                         /* Check if the device queue is big
269                          * enough for every fragment. If not, drop the
270                          * whole packet.
271                          */
272                         for (i = 0; i < packet->txb->nr_frags; i++) {
273                                 skb = packet->txb->fragments[i];
274                                 if (unlikely(skb->len > queue->tx_devq_size)) {
275                                         dprintkl(KERN_ERR PFX "PIO TX device queue too small. "
276                                                               "Dropping packet.\n");
277                                         free_txpacket(packet, 1);
278                                         goto next_packet;
279                                 }
280                         }
281                 }
282                 /* Try to transmit the packet.
283                  * This may not completely succeed.
284                  */
285                 err = pio_tx_packet(packet);
286                 if (err)
287                         break;
288         next_packet:
289                 continue;
290         }
291         bcm43xx_unlock_mmio(bcm, flags);
292 }
293
294 static void setup_txqueues(struct bcm43xx_pioqueue *queue)
295 {
296         struct bcm43xx_pio_txpacket *packet;
297         int i;
298
299         queue->nr_txfree = BCM43xx_PIO_MAXTXPACKETS;
300         for (i = 0; i < BCM43xx_PIO_MAXTXPACKETS; i++) {
301                 packet = &(queue->tx_packets_cache[i]);
302
303                 packet->queue = queue;
304                 INIT_LIST_HEAD(&packet->list);
305
306                 list_add(&packet->list, &queue->txfree);
307         }
308 }
309
310 static
311 struct bcm43xx_pioqueue * bcm43xx_setup_pioqueue(struct bcm43xx_private *bcm,
312                                                  u16 pio_mmio_base)
313 {
314         struct bcm43xx_pioqueue *queue;
315         u32 value;
316         u16 qsize;
317
318         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
319         if (!queue)
320                 goto out;
321
322         queue->bcm = bcm;
323         queue->mmio_base = pio_mmio_base;
324         queue->need_workarounds = (bcm->current_core->rev < 3);
325
326         INIT_LIST_HEAD(&queue->txfree);
327         INIT_LIST_HEAD(&queue->txqueue);
328         INIT_LIST_HEAD(&queue->txrunning);
329         tasklet_init(&queue->txtask, tx_tasklet,
330                      (unsigned long)queue);
331
332         value = bcm43xx_read32(bcm, BCM43xx_MMIO_STATUS_BITFIELD);
333         value |= BCM43xx_SBF_XFER_REG_BYTESWAP;
334         bcm43xx_write32(bcm, BCM43xx_MMIO_STATUS_BITFIELD, value);
335
336         qsize = bcm43xx_read16(bcm, queue->mmio_base + BCM43xx_PIO_TXQBUFSIZE);
337         if (qsize <= BCM43xx_PIO_TXQADJUST) {
338                 printk(KERN_ERR PFX "PIO tx device-queue too small (%u)\n", qsize);
339                 goto err_freequeue;
340         }
341         qsize -= BCM43xx_PIO_TXQADJUST;
342         queue->tx_devq_size = qsize;
343
344         setup_txqueues(queue);
345
346 out:
347         return queue;
348
349 err_freequeue:
350         kfree(queue);
351         queue = NULL;
352         goto out;
353 }
354
355 static void cancel_transfers(struct bcm43xx_pioqueue *queue)
356 {
357         struct bcm43xx_pio_txpacket *packet, *tmp_packet;
358
359         netif_tx_disable(queue->bcm->net_dev);
360         assert(queue->bcm->shutting_down);
361         tasklet_disable(&queue->txtask);
362
363         list_for_each_entry_safe(packet, tmp_packet, &queue->txrunning, list)
364                 free_txpacket(packet, 0);
365         list_for_each_entry_safe(packet, tmp_packet, &queue->txqueue, list)
366                 free_txpacket(packet, 0);
367 }
368
369 static void bcm43xx_destroy_pioqueue(struct bcm43xx_pioqueue *queue)
370 {
371         if (!queue)
372                 return;
373
374         cancel_transfers(queue);
375         kfree(queue);
376 }
377
378 void bcm43xx_pio_free(struct bcm43xx_private *bcm)
379 {
380         struct bcm43xx_pio *pio;
381
382         if (!bcm43xx_using_pio(bcm))
383                 return;
384         pio = bcm43xx_current_pio(bcm);
385
386         bcm43xx_destroy_pioqueue(pio->queue3);
387         pio->queue3 = NULL;
388         bcm43xx_destroy_pioqueue(pio->queue2);
389         pio->queue2 = NULL;
390         bcm43xx_destroy_pioqueue(pio->queue1);
391         pio->queue1 = NULL;
392         bcm43xx_destroy_pioqueue(pio->queue0);
393         pio->queue0 = NULL;
394 }
395
396 int bcm43xx_pio_init(struct bcm43xx_private *bcm)
397 {
398         struct bcm43xx_pio *pio = bcm43xx_current_pio(bcm);
399         struct bcm43xx_pioqueue *queue;
400         int err = -ENOMEM;
401
402         queue = bcm43xx_setup_pioqueue(bcm, BCM43xx_MMIO_PIO1_BASE);
403         if (!queue)
404                 goto out;
405         pio->queue0 = queue;
406
407         queue = bcm43xx_setup_pioqueue(bcm, BCM43xx_MMIO_PIO2_BASE);
408         if (!queue)
409                 goto err_destroy0;
410         pio->queue1 = queue;
411
412         queue = bcm43xx_setup_pioqueue(bcm, BCM43xx_MMIO_PIO3_BASE);
413         if (!queue)
414                 goto err_destroy1;
415         pio->queue2 = queue;
416
417         queue = bcm43xx_setup_pioqueue(bcm, BCM43xx_MMIO_PIO4_BASE);
418         if (!queue)
419                 goto err_destroy2;
420         pio->queue3 = queue;
421
422         if (bcm->current_core->rev < 3)
423                 bcm->irq_savedstate |= BCM43xx_IRQ_PIO_WORKAROUND;
424
425         dprintk(KERN_INFO PFX "PIO initialized\n");
426         err = 0;
427 out:
428         return err;
429
430 err_destroy2:
431         bcm43xx_destroy_pioqueue(pio->queue2);
432         pio->queue2 = NULL;
433 err_destroy1:
434         bcm43xx_destroy_pioqueue(pio->queue1);
435         pio->queue1 = NULL;
436 err_destroy0:
437         bcm43xx_destroy_pioqueue(pio->queue0);
438         pio->queue0 = NULL;
439         goto out;
440 }
441
442 int bcm43xx_pio_tx(struct bcm43xx_private *bcm,
443                    struct ieee80211_txb *txb)
444 {
445         struct bcm43xx_pioqueue *queue = bcm43xx_current_pio(bcm)->queue1;
446         struct bcm43xx_pio_txpacket *packet;
447         u16 tmp;
448
449         assert(!queue->tx_suspended);
450         assert(!list_empty(&queue->txfree));
451
452         tmp = bcm43xx_pio_read(queue, BCM43xx_PIO_TXCTL);
453         if (tmp & BCM43xx_PIO_TXCTL_SUSPEND)
454                 return -EBUSY;
455
456         packet = list_entry(queue->txfree.next, struct bcm43xx_pio_txpacket, list);
457         packet->txb = txb;
458         packet->xmitted_frags = 0;
459         packet->xmitted_octets = 0;
460         list_move_tail(&packet->list, &queue->txqueue);
461         queue->nr_txfree--;
462         assert(queue->nr_txfree < BCM43xx_PIO_MAXTXPACKETS);
463
464         /* Suspend TX, if we are out of packets in the "free" queue. */
465         if (unlikely(list_empty(&queue->txfree))) {
466                 netif_stop_queue(queue->bcm->net_dev);
467                 queue->tx_suspended = 1;
468         }
469
470         tasklet_schedule(&queue->txtask);
471
472         return 0;
473 }
474
475 void bcm43xx_pio_handle_xmitstatus(struct bcm43xx_private *bcm,
476                                    struct bcm43xx_xmitstatus *status)
477 {
478         struct bcm43xx_pioqueue *queue;
479         struct bcm43xx_pio_txpacket *packet;
480
481         queue = parse_cookie(bcm, status->cookie, &packet);
482         assert(queue);
483 //TODO
484 if (!queue)
485 return;
486         free_txpacket(packet, 1);
487         if (unlikely(queue->tx_suspended)) {
488                 queue->tx_suspended = 0;
489                 netif_wake_queue(queue->bcm->net_dev);
490         }
491         /* If there are packets on the txqueue, poke the tasklet. */
492         if (!list_empty(&queue->txqueue))
493                 tasklet_schedule(&queue->txtask);
494 }
495
496 static void pio_rx_error(struct bcm43xx_pioqueue *queue,
497                          int clear_buffers,
498                          const char *error)
499 {
500         int i;
501
502         printkl("PIO RX error: %s\n", error);
503         bcm43xx_pio_write(queue, BCM43xx_PIO_RXCTL,
504                           BCM43xx_PIO_RXCTL_READY);
505         if (clear_buffers) {
506                 assert(queue->mmio_base == BCM43xx_MMIO_PIO1_BASE);
507                 for (i = 0; i < 15; i++) {
508                         /* Dummy read. */
509                         bcm43xx_pio_read(queue, BCM43xx_PIO_RXDATA);
510                 }
511         }
512 }
513
514 void bcm43xx_pio_rx(struct bcm43xx_pioqueue *queue)
515 {
516         u16 preamble[21] = { 0 };
517         struct bcm43xx_rxhdr *rxhdr;
518         u16 tmp, len, rxflags2;
519         int i, preamble_readwords;
520         struct sk_buff *skb;
521
522 return;
523         tmp = bcm43xx_pio_read(queue, BCM43xx_PIO_RXCTL);
524         if (!(tmp & BCM43xx_PIO_RXCTL_DATAAVAILABLE)) {
525                 dprintkl(KERN_ERR PFX "PIO RX: No data available\n");//TODO: remove this printk.
526                 return;
527         }
528         bcm43xx_pio_write(queue, BCM43xx_PIO_RXCTL,
529                           BCM43xx_PIO_RXCTL_DATAAVAILABLE);
530
531         for (i = 0; i < 10; i++) {
532                 tmp = bcm43xx_pio_read(queue, BCM43xx_PIO_RXCTL);
533                 if (tmp & BCM43xx_PIO_RXCTL_READY)
534                         goto data_ready;
535                 udelay(10);
536         }
537         dprintkl(KERN_ERR PFX "PIO RX timed out\n");
538         return;
539 data_ready:
540
541 //FIXME: endianess in this function.
542         len = le16_to_cpu(bcm43xx_pio_read(queue, BCM43xx_PIO_RXDATA));
543         if (unlikely(len > 0x700)) {
544                 pio_rx_error(queue, 0, "len > 0x700");
545                 return;
546         }
547         if (unlikely(len == 0 && queue->mmio_base != BCM43xx_MMIO_PIO4_BASE)) {
548                 pio_rx_error(queue, 0, "len == 0");
549                 return;
550         }
551         preamble[0] = cpu_to_le16(len);
552         if (queue->mmio_base == BCM43xx_MMIO_PIO4_BASE)
553                 preamble_readwords = 14 / sizeof(u16);
554         else
555                 preamble_readwords = 18 / sizeof(u16);
556         for (i = 0; i < preamble_readwords; i++) {
557                 tmp = bcm43xx_pio_read(queue, BCM43xx_PIO_RXDATA);
558                 preamble[i + 1] = cpu_to_be16(tmp);//FIXME?
559         }
560         rxhdr = (struct bcm43xx_rxhdr *)preamble;
561         rxflags2 = le16_to_cpu(rxhdr->flags2);
562         if (unlikely(rxflags2 & BCM43xx_RXHDR_FLAGS2_INVALIDFRAME)) {
563                 pio_rx_error(queue,
564                              (queue->mmio_base == BCM43xx_MMIO_PIO1_BASE),
565                              "invalid frame");
566                 return;
567         }
568         if (queue->mmio_base == BCM43xx_MMIO_PIO4_BASE) {
569                 /* We received an xmit status. */
570                 struct bcm43xx_hwxmitstatus *hw;
571                 struct bcm43xx_xmitstatus stat;
572
573                 hw = (struct bcm43xx_hwxmitstatus *)(preamble + 1);
574                 stat.cookie = le16_to_cpu(hw->cookie);
575                 stat.flags = hw->flags;
576                 stat.cnt1 = hw->cnt1;
577                 stat.cnt2 = hw->cnt2;
578                 stat.seq = le16_to_cpu(hw->seq);
579                 stat.unknown = le16_to_cpu(hw->unknown);
580
581                 bcm43xx_debugfs_log_txstat(queue->bcm, &stat);
582                 bcm43xx_pio_handle_xmitstatus(queue->bcm, &stat);
583
584                 return;
585         }
586
587         skb = dev_alloc_skb(len);
588         if (unlikely(!skb)) {
589                 pio_rx_error(queue, 1, "OOM");
590                 return;
591         }
592         skb_put(skb, len);
593         for (i = 0; i < len - 1; i += 2) {
594                 tmp = cpu_to_be16(bcm43xx_pio_read(queue, BCM43xx_PIO_RXDATA));
595                 *((u16 *)(skb->data + i)) = tmp;
596         }
597         if (len % 2) {
598                 tmp = bcm43xx_pio_read(queue, BCM43xx_PIO_RXDATA);
599                 skb->data[len - 1] = (tmp & 0x00FF);
600                 if (rxflags2 & BCM43xx_RXHDR_FLAGS2_TYPE2FRAME)
601                         skb->data[0x20] = (tmp & 0xFF00) >> 8;
602                 else
603                         skb->data[0x1E] = (tmp & 0xFF00) >> 8;
604         }
605         bcm43xx_rx(queue->bcm, skb, rxhdr);
606 }