1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Device handling thread implementation for mac80211 ST-Ericsson CW1200 drivers
4 *
5 * Copyright (c) 2010, ST-Ericsson
6 * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
7 *
8 * Based on:
9 * ST-Ericsson UMAC CW1200 driver, which is
10 * Copyright (c) 2010, ST-Ericsson
11 * Author: Ajitpal Singh <ajitpal.singh@stericsson.com>
12 */
13
14 #include <linux/module.h>
15 #include <net/mac80211.h>
16 #include <linux/kthread.h>
17 #include <linux/timer.h>
18
19 #include "cw1200.h"
20 #include "bh.h"
21 #include "hwio.h"
22 #include "wsm.h"
23 #include "hwbus.h"
24 #include "debug.h"
25 #include "fwio.h"
26
27 static int cw1200_bh(void *arg);
28
29 #define DOWNLOAD_BLOCK_SIZE_WR (0x1000 - 4)
30 /* an SPI message cannot be bigger than (2"12-1)*2 bytes
31 * "*2" to cvt to bytes
32 */
33 #define MAX_SZ_RD_WR_BUFFERS (DOWNLOAD_BLOCK_SIZE_WR*2)
34 #define PIGGYBACK_CTRL_REG (2)
35 #define EFFECTIVE_BUF_SIZE (MAX_SZ_RD_WR_BUFFERS - PIGGYBACK_CTRL_REG)
36
37 /* Suspend state privates */
38 enum cw1200_bh_pm_state {
39 CW1200_BH_RESUMED = 0,
40 CW1200_BH_SUSPEND,
41 CW1200_BH_SUSPENDED,
42 CW1200_BH_RESUME,
43 };
44
45 typedef int (*cw1200_wsm_handler)(struct cw1200_common *priv,
46 u8 *data, size_t size);
47
cw1200_bh_work(struct work_struct * work)48 static void cw1200_bh_work(struct work_struct *work)
49 {
50 struct cw1200_common *priv =
51 container_of(work, struct cw1200_common, bh_work);
52 cw1200_bh(priv);
53 }
54
cw1200_register_bh(struct cw1200_common * priv)55 int cw1200_register_bh(struct cw1200_common *priv)
56 {
57 int err = 0;
58 /* Realtime workqueue */
59 priv->bh_workqueue = alloc_workqueue("cw1200_bh",
60 WQ_MEM_RECLAIM | WQ_HIGHPRI
61 | WQ_CPU_INTENSIVE, 1);
62
63 if (!priv->bh_workqueue)
64 return -ENOMEM;
65
66 INIT_WORK(&priv->bh_work, cw1200_bh_work);
67
68 pr_debug("[BH] register.\n");
69
70 atomic_set(&priv->bh_rx, 0);
71 atomic_set(&priv->bh_tx, 0);
72 atomic_set(&priv->bh_term, 0);
73 atomic_set(&priv->bh_suspend, CW1200_BH_RESUMED);
74 priv->bh_error = 0;
75 priv->hw_bufs_used = 0;
76 priv->buf_id_tx = 0;
77 priv->buf_id_rx = 0;
78 init_waitqueue_head(&priv->bh_wq);
79 init_waitqueue_head(&priv->bh_evt_wq);
80
81 err = !queue_work(priv->bh_workqueue, &priv->bh_work);
82 WARN_ON(err);
83 return err;
84 }
85
cw1200_unregister_bh(struct cw1200_common * priv)86 void cw1200_unregister_bh(struct cw1200_common *priv)
87 {
88 atomic_add(1, &priv->bh_term);
89 wake_up(&priv->bh_wq);
90
91 flush_workqueue(priv->bh_workqueue);
92
93 destroy_workqueue(priv->bh_workqueue);
94 priv->bh_workqueue = NULL;
95
96 pr_debug("[BH] unregistered.\n");
97 }
98
cw1200_irq_handler(struct cw1200_common * priv)99 void cw1200_irq_handler(struct cw1200_common *priv)
100 {
101 pr_debug("[BH] irq.\n");
102
103 /* Disable Interrupts! */
104 /* NOTE: hwbus_ops->lock already held */
105 __cw1200_irq_enable(priv, 0);
106
107 if (/* WARN_ON */(priv->bh_error))
108 return;
109
110 if (atomic_add_return(1, &priv->bh_rx) == 1)
111 wake_up(&priv->bh_wq);
112 }
113 EXPORT_SYMBOL_GPL(cw1200_irq_handler);
114
cw1200_bh_wakeup(struct cw1200_common * priv)115 void cw1200_bh_wakeup(struct cw1200_common *priv)
116 {
117 pr_debug("[BH] wakeup.\n");
118 if (priv->bh_error) {
119 pr_err("[BH] wakeup failed (BH error)\n");
120 return;
121 }
122
123 if (atomic_add_return(1, &priv->bh_tx) == 1)
124 wake_up(&priv->bh_wq);
125 }
126
cw1200_bh_suspend(struct cw1200_common * priv)127 int cw1200_bh_suspend(struct cw1200_common *priv)
128 {
129 pr_debug("[BH] suspend.\n");
130 if (priv->bh_error) {
131 wiphy_warn(priv->hw->wiphy, "BH error -- can't suspend\n");
132 return -EINVAL;
133 }
134
135 atomic_set(&priv->bh_suspend, CW1200_BH_SUSPEND);
136 wake_up(&priv->bh_wq);
137 return wait_event_timeout(priv->bh_evt_wq, priv->bh_error ||
138 (CW1200_BH_SUSPENDED == atomic_read(&priv->bh_suspend)),
139 1 * HZ) ? 0 : -ETIMEDOUT;
140 }
141
cw1200_bh_resume(struct cw1200_common * priv)142 int cw1200_bh_resume(struct cw1200_common *priv)
143 {
144 pr_debug("[BH] resume.\n");
145 if (priv->bh_error) {
146 wiphy_warn(priv->hw->wiphy, "BH error -- can't resume\n");
147 return -EINVAL;
148 }
149
150 atomic_set(&priv->bh_suspend, CW1200_BH_RESUME);
151 wake_up(&priv->bh_wq);
152 return wait_event_timeout(priv->bh_evt_wq, priv->bh_error ||
153 (CW1200_BH_RESUMED == atomic_read(&priv->bh_suspend)),
154 1 * HZ) ? 0 : -ETIMEDOUT;
155 }
156
wsm_alloc_tx_buffer(struct cw1200_common * priv)157 static inline void wsm_alloc_tx_buffer(struct cw1200_common *priv)
158 {
159 ++priv->hw_bufs_used;
160 }
161
wsm_release_tx_buffer(struct cw1200_common * priv,int count)162 int wsm_release_tx_buffer(struct cw1200_common *priv, int count)
163 {
164 int ret = 0;
165 int hw_bufs_used = priv->hw_bufs_used;
166
167 priv->hw_bufs_used -= count;
168 if (WARN_ON(priv->hw_bufs_used < 0))
169 ret = -1;
170 else if (hw_bufs_used >= priv->wsm_caps.input_buffers)
171 ret = 1;
172 if (!priv->hw_bufs_used)
173 wake_up(&priv->bh_evt_wq);
174 return ret;
175 }
176
cw1200_bh_read_ctrl_reg(struct cw1200_common * priv,u16 * ctrl_reg)177 static int cw1200_bh_read_ctrl_reg(struct cw1200_common *priv,
178 u16 *ctrl_reg)
179 {
180 int ret;
181
182 ret = cw1200_reg_read_16(priv,
183 ST90TDS_CONTROL_REG_ID, ctrl_reg);
184 if (ret) {
185 ret = cw1200_reg_read_16(priv,
186 ST90TDS_CONTROL_REG_ID, ctrl_reg);
187 if (ret)
188 pr_err("[BH] Failed to read control register.\n");
189 }
190
191 return ret;
192 }
193
cw1200_device_wakeup(struct cw1200_common * priv)194 static int cw1200_device_wakeup(struct cw1200_common *priv)
195 {
196 u16 ctrl_reg;
197 int ret;
198
199 pr_debug("[BH] Device wakeup.\n");
200
201 /* First, set the dpll register */
202 ret = cw1200_reg_write_32(priv, ST90TDS_TSET_GEN_R_W_REG_ID,
203 cw1200_dpll_from_clk(priv->hw_refclk));
204 if (WARN_ON(ret))
205 return ret;
206
207 /* To force the device to be always-on, the host sets WLAN_UP to 1 */
208 ret = cw1200_reg_write_16(priv, ST90TDS_CONTROL_REG_ID,
209 ST90TDS_CONT_WUP_BIT);
210 if (WARN_ON(ret))
211 return ret;
212
213 ret = cw1200_bh_read_ctrl_reg(priv, &ctrl_reg);
214 if (WARN_ON(ret))
215 return ret;
216
217 /* If the device returns WLAN_RDY as 1, the device is active and will
218 * remain active.
219 */
220 if (ctrl_reg & ST90TDS_CONT_RDY_BIT) {
221 pr_debug("[BH] Device awake.\n");
222 return 1;
223 }
224
225 return 0;
226 }
227
228 /* Must be called from BH thraed. */
cw1200_enable_powersave(struct cw1200_common * priv,bool enable)229 void cw1200_enable_powersave(struct cw1200_common *priv,
230 bool enable)
231 {
232 pr_debug("[BH] Powerave is %s.\n",
233 enable ? "enabled" : "disabled");
234 priv->powersave_enabled = enable;
235 }
236
cw1200_bh_rx_helper(struct cw1200_common * priv,uint16_t * ctrl_reg,int * tx)237 static int cw1200_bh_rx_helper(struct cw1200_common *priv,
238 uint16_t *ctrl_reg,
239 int *tx)
240 {
241 size_t read_len = 0;
242 struct sk_buff *skb_rx = NULL;
243 struct wsm_hdr *wsm;
244 size_t wsm_len;
245 u16 wsm_id;
246 u8 wsm_seq;
247 int rx_resync = 1;
248
249 size_t alloc_len;
250 u8 *data;
251
252 read_len = (*ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK) * 2;
253 if (!read_len)
254 return 0; /* No more work */
255
256 if (WARN_ON((read_len < sizeof(struct wsm_hdr)) ||
257 (read_len > EFFECTIVE_BUF_SIZE))) {
258 pr_debug("Invalid read len: %zu (%04x)",
259 read_len, *ctrl_reg);
260 goto err;
261 }
262
263 /* Add SIZE of PIGGYBACK reg (CONTROL Reg)
264 * to the NEXT Message length + 2 Bytes for SKB
265 */
266 read_len = read_len + 2;
267
268 alloc_len = priv->hwbus_ops->align_size(
269 priv->hwbus_priv, read_len);
270
271 /* Check if not exceeding CW1200 capabilities */
272 if (WARN_ON_ONCE(alloc_len > EFFECTIVE_BUF_SIZE)) {
273 pr_debug("Read aligned len: %zu\n",
274 alloc_len);
275 }
276
277 skb_rx = dev_alloc_skb(alloc_len);
278 if (WARN_ON(!skb_rx))
279 goto err;
280
281 skb_trim(skb_rx, 0);
282 skb_put(skb_rx, read_len);
283 data = skb_rx->data;
284 if (WARN_ON(!data))
285 goto err;
286
287 if (WARN_ON(cw1200_data_read(priv, data, alloc_len))) {
288 pr_err("rx blew up, len %zu\n", alloc_len);
289 goto err;
290 }
291
292 /* Piggyback */
293 *ctrl_reg = __le16_to_cpu(
294 ((__le16 *)data)[alloc_len / 2 - 1]);
295
296 wsm = (struct wsm_hdr *)data;
297 wsm_len = __le16_to_cpu(wsm->len);
298 if (WARN_ON(wsm_len > read_len))
299 goto err;
300
301 if (priv->wsm_enable_wsm_dumps)
302 print_hex_dump_bytes("<-- ",
303 DUMP_PREFIX_NONE,
304 data, wsm_len);
305
306 wsm_id = __le16_to_cpu(wsm->id) & 0xFFF;
307 wsm_seq = (__le16_to_cpu(wsm->id) >> 13) & 7;
308
309 skb_trim(skb_rx, wsm_len);
310
311 if (wsm_id == 0x0800) {
312 wsm_handle_exception(priv,
313 &data[sizeof(*wsm)],
314 wsm_len - sizeof(*wsm));
315 goto err;
316 } else if (!rx_resync) {
317 if (WARN_ON(wsm_seq != priv->wsm_rx_seq))
318 goto err;
319 }
320 priv->wsm_rx_seq = (wsm_seq + 1) & 7;
321 rx_resync = 0;
322
323 if (wsm_id & 0x0400) {
324 int rc = wsm_release_tx_buffer(priv, 1);
325 if (WARN_ON(rc < 0))
326 return rc;
327 else if (rc > 0)
328 *tx = 1;
329 }
330
331 /* cw1200_wsm_rx takes care on SKB livetime */
332 if (WARN_ON(wsm_handle_rx(priv, wsm_id, wsm, &skb_rx)))
333 goto err;
334
335 if (skb_rx) {
336 dev_kfree_skb(skb_rx);
337 skb_rx = NULL;
338 }
339
340 return 0;
341
342 err:
343 if (skb_rx) {
344 dev_kfree_skb(skb_rx);
345 skb_rx = NULL;
346 }
347 return -1;
348 }
349
cw1200_bh_tx_helper(struct cw1200_common * priv,int * pending_tx,int * tx_burst)350 static int cw1200_bh_tx_helper(struct cw1200_common *priv,
351 int *pending_tx,
352 int *tx_burst)
353 {
354 size_t tx_len;
355 u8 *data;
356 int ret;
357 struct wsm_hdr *wsm;
358
359 if (priv->device_can_sleep) {
360 ret = cw1200_device_wakeup(priv);
361 if (WARN_ON(ret < 0)) { /* Error in wakeup */
362 *pending_tx = 1;
363 return 0;
364 } else if (ret) { /* Woke up */
365 priv->device_can_sleep = false;
366 } else { /* Did not awake */
367 *pending_tx = 1;
368 return 0;
369 }
370 }
371
372 wsm_alloc_tx_buffer(priv);
373 ret = wsm_get_tx(priv, &data, &tx_len, tx_burst);
374 if (ret <= 0) {
375 wsm_release_tx_buffer(priv, 1);
376 if (WARN_ON(ret < 0))
377 return ret; /* Error */
378 return 0; /* No work */
379 }
380
381 wsm = (struct wsm_hdr *)data;
382 BUG_ON(tx_len < sizeof(*wsm));
383 BUG_ON(__le16_to_cpu(wsm->len) != tx_len);
384
385 atomic_add(1, &priv->bh_tx);
386
387 tx_len = priv->hwbus_ops->align_size(
388 priv->hwbus_priv, tx_len);
389
390 /* Check if not exceeding CW1200 capabilities */
391 if (WARN_ON_ONCE(tx_len > EFFECTIVE_BUF_SIZE))
392 pr_debug("Write aligned len: %zu\n", tx_len);
393
394 wsm->id &= __cpu_to_le16(0xffff ^ WSM_TX_SEQ(WSM_TX_SEQ_MAX));
395 wsm->id |= __cpu_to_le16(WSM_TX_SEQ(priv->wsm_tx_seq));
396
397 if (WARN_ON(cw1200_data_write(priv, data, tx_len))) {
398 pr_err("tx blew up, len %zu\n", tx_len);
399 wsm_release_tx_buffer(priv, 1);
400 return -1; /* Error */
401 }
402
403 if (priv->wsm_enable_wsm_dumps)
404 print_hex_dump_bytes("--> ",
405 DUMP_PREFIX_NONE,
406 data,
407 __le16_to_cpu(wsm->len));
408
409 wsm_txed(priv, data);
410 priv->wsm_tx_seq = (priv->wsm_tx_seq + 1) & WSM_TX_SEQ_MAX;
411
412 if (*tx_burst > 1) {
413 cw1200_debug_tx_burst(priv);
414 return 1; /* Work remains */
415 }
416
417 return 0;
418 }
419
cw1200_bh(void * arg)420 static int cw1200_bh(void *arg)
421 {
422 struct cw1200_common *priv = arg;
423 int rx, tx, term, suspend;
424 u16 ctrl_reg = 0;
425 int tx_allowed;
426 int pending_tx = 0;
427 int tx_burst;
428 long status;
429 u32 dummy;
430 int ret;
431
432 for (;;) {
433 if (!priv->hw_bufs_used &&
434 priv->powersave_enabled &&
435 !priv->device_can_sleep &&
436 !atomic_read(&priv->recent_scan)) {
437 status = 1 * HZ;
438 pr_debug("[BH] Device wakedown. No data.\n");
439 cw1200_reg_write_16(priv, ST90TDS_CONTROL_REG_ID, 0);
440 priv->device_can_sleep = true;
441 } else if (priv->hw_bufs_used) {
442 /* Interrupt loss detection */
443 status = 1 * HZ;
444 } else {
445 status = MAX_SCHEDULE_TIMEOUT;
446 }
447
448 /* Dummy Read for SDIO retry mechanism*/
449 if ((priv->hw_type != -1) &&
450 (atomic_read(&priv->bh_rx) == 0) &&
451 (atomic_read(&priv->bh_tx) == 0))
452 cw1200_reg_read(priv, ST90TDS_CONFIG_REG_ID,
453 &dummy, sizeof(dummy));
454
455 pr_debug("[BH] waiting ...\n");
456 status = wait_event_interruptible_timeout(priv->bh_wq, ({
457 rx = atomic_xchg(&priv->bh_rx, 0);
458 tx = atomic_xchg(&priv->bh_tx, 0);
459 term = atomic_xchg(&priv->bh_term, 0);
460 suspend = pending_tx ?
461 0 : atomic_read(&priv->bh_suspend);
462 (rx || tx || term || suspend || priv->bh_error);
463 }), status);
464
465 pr_debug("[BH] - rx: %d, tx: %d, term: %d, bh_err: %d, suspend: %d, status: %ld\n",
466 rx, tx, term, suspend, priv->bh_error, status);
467
468 /* Did an error occur? */
469 if ((status < 0 && status != -ERESTARTSYS) ||
470 term || priv->bh_error) {
471 break;
472 }
473 if (!status) { /* wait_event timed out */
474 unsigned long timestamp = jiffies;
475 long timeout;
476 int pending = 0;
477 int i;
478
479 /* Check to see if we have any outstanding frames */
480 if (priv->hw_bufs_used && (!rx || !tx)) {
481 wiphy_warn(priv->hw->wiphy,
482 "Missed interrupt? (%d frames outstanding)\n",
483 priv->hw_bufs_used);
484 rx = 1;
485
486 /* Get a timestamp of "oldest" frame */
487 for (i = 0; i < 4; ++i)
488 pending += cw1200_queue_get_xmit_timestamp(
489 &priv->tx_queue[i],
490 ×tamp,
491 priv->pending_frame_id);
492
493 /* Check if frame transmission is timed out.
494 * Add an extra second with respect to possible
495 * interrupt loss.
496 */
497 timeout = timestamp +
498 WSM_CMD_LAST_CHANCE_TIMEOUT +
499 1 * HZ -
500 jiffies;
501
502 /* And terminate BH thread if the frame is "stuck" */
503 if (pending && timeout < 0) {
504 wiphy_warn(priv->hw->wiphy,
505 "Timeout waiting for TX confirm (%d/%d pending, %ld vs %lu).\n",
506 priv->hw_bufs_used, pending,
507 timestamp, jiffies);
508 break;
509 }
510 } else if (!priv->device_can_sleep &&
511 !atomic_read(&priv->recent_scan)) {
512 pr_debug("[BH] Device wakedown. Timeout.\n");
513 cw1200_reg_write_16(priv,
514 ST90TDS_CONTROL_REG_ID, 0);
515 priv->device_can_sleep = true;
516 }
517 goto done;
518 } else if (suspend) {
519 pr_debug("[BH] Device suspend.\n");
520 if (priv->powersave_enabled) {
521 pr_debug("[BH] Device wakedown. Suspend.\n");
522 cw1200_reg_write_16(priv,
523 ST90TDS_CONTROL_REG_ID, 0);
524 priv->device_can_sleep = true;
525 }
526
527 atomic_set(&priv->bh_suspend, CW1200_BH_SUSPENDED);
528 wake_up(&priv->bh_evt_wq);
529 status = wait_event_interruptible(priv->bh_wq,
530 CW1200_BH_RESUME == atomic_read(&priv->bh_suspend));
531 if (status < 0) {
532 wiphy_err(priv->hw->wiphy,
533 "Failed to wait for resume: %ld.\n",
534 status);
535 break;
536 }
537 pr_debug("[BH] Device resume.\n");
538 atomic_set(&priv->bh_suspend, CW1200_BH_RESUMED);
539 wake_up(&priv->bh_evt_wq);
540 atomic_add(1, &priv->bh_rx);
541 goto done;
542 }
543
544 rx:
545 tx += pending_tx;
546 pending_tx = 0;
547
548 if (cw1200_bh_read_ctrl_reg(priv, &ctrl_reg))
549 break;
550
551 /* Don't bother trying to rx unless we have data to read */
552 if (ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK) {
553 ret = cw1200_bh_rx_helper(priv, &ctrl_reg, &tx);
554 if (ret < 0)
555 break;
556 /* Double up here if there's more data.. */
557 if (ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK) {
558 ret = cw1200_bh_rx_helper(priv, &ctrl_reg, &tx);
559 if (ret < 0)
560 break;
561 }
562 }
563
564 tx:
565 if (tx) {
566 tx = 0;
567
568 BUG_ON(priv->hw_bufs_used > priv->wsm_caps.input_buffers);
569 tx_burst = priv->wsm_caps.input_buffers - priv->hw_bufs_used;
570 tx_allowed = tx_burst > 0;
571
572 if (!tx_allowed) {
573 /* Buffers full. Ensure we process tx
574 * after we handle rx..
575 */
576 pending_tx = tx;
577 goto done_rx;
578 }
579 ret = cw1200_bh_tx_helper(priv, &pending_tx, &tx_burst);
580 if (ret < 0)
581 break;
582 if (ret > 0) /* More to transmit */
583 tx = ret;
584
585 /* Re-read ctrl reg */
586 if (cw1200_bh_read_ctrl_reg(priv, &ctrl_reg))
587 break;
588 }
589
590 done_rx:
591 if (priv->bh_error)
592 break;
593 if (ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK)
594 goto rx;
595 if (tx)
596 goto tx;
597
598 done:
599 /* Re-enable device interrupts */
600 priv->hwbus_ops->lock(priv->hwbus_priv);
601 __cw1200_irq_enable(priv, 1);
602 priv->hwbus_ops->unlock(priv->hwbus_priv);
603 }
604
605 /* Explicitly disable device interrupts */
606 priv->hwbus_ops->lock(priv->hwbus_priv);
607 __cw1200_irq_enable(priv, 0);
608 priv->hwbus_ops->unlock(priv->hwbus_priv);
609
610 if (!term) {
611 pr_err("[BH] Fatal error, exiting.\n");
612 priv->bh_error = 1;
613 /* TODO: schedule_work(recovery) */
614 }
615 return 0;
616 }
617