xref: /openbmc/linux/drivers/net/wireless/ath/ath5k/qcu.c (revision f3539c12)
1 /*
2  * Copyright (c) 2004-2008 Reyk Floeter <reyk@openbsd.org>
3  * Copyright (c) 2006-2008 Nick Kossifidis <mickflemm@gmail.com>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  *
17  */
18 
19 /********************************************\
20 Queue Control Unit, DCF Control Unit Functions
21 \********************************************/
22 
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 
25 #include "ath5k.h"
26 #include "reg.h"
27 #include "debug.h"
28 #include <linux/log2.h>
29 
30 /**
31  * DOC: Queue Control Unit (QCU)/DCF Control Unit (DCU) functions
32  *
33  * Here we setup parameters for the 12 available TX queues. Note that
34  * on the various registers we can usually only map the first 10 of them so
35  * basically we have 10 queues to play with. Each queue has a matching
36  * QCU that controls when the queue will get triggered and multiple QCUs
37  * can be mapped to a single DCU that controls the various DFS parameters
38  * for the various queues. In our setup we have a 1:1 mapping between QCUs
39  * and DCUs allowing us to have different DFS settings for each queue.
40  *
41  * When a frame goes into a TX queue, QCU decides when it'll trigger a
42  * transmission based on various criteria (such as how many data we have inside
43  * it's buffer or -if it's a beacon queue- if it's time to fire up the queue
44  * based on TSF etc), DCU adds backoff, IFSes etc and then a scheduler
45  * (arbitrator) decides the priority of each QCU based on it's configuration
46  * (e.g. beacons are always transmitted when they leave DCU bypassing all other
47  * frames from other queues waiting to be transmitted). After a frame leaves
48  * the DCU it goes to PCU for further processing and then to PHY for
49  * the actual transmission.
50  */
51 
52 
53 /******************\
54 * Helper functions *
55 \******************/
56 
57 /**
58  * ath5k_hw_num_tx_pending() - Get number of pending frames for a  given queue
59  * @ah: The &struct ath5k_hw
60  * @queue: One of enum ath5k_tx_queue_id
61  */
62 u32
63 ath5k_hw_num_tx_pending(struct ath5k_hw *ah, unsigned int queue)
64 {
65 	u32 pending;
66 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
67 
68 	/* Return if queue is declared inactive */
69 	if (ah->ah_txq[queue].tqi_type == AR5K_TX_QUEUE_INACTIVE)
70 		return false;
71 
72 	/* XXX: How about AR5K_CFG_TXCNT ? */
73 	if (ah->ah_version == AR5K_AR5210)
74 		return false;
75 
76 	pending = ath5k_hw_reg_read(ah, AR5K_QUEUE_STATUS(queue));
77 	pending &= AR5K_QCU_STS_FRMPENDCNT;
78 
79 	/* It's possible to have no frames pending even if TXE
80 	 * is set. To indicate that q has not stopped return
81 	 * true */
82 	if (!pending && AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue))
83 		return true;
84 
85 	return pending;
86 }
87 
88 /**
89  * ath5k_hw_release_tx_queue() - Set a transmit queue inactive
90  * @ah: The &struct ath5k_hw
91  * @queue: One of enum ath5k_tx_queue_id
92  */
93 void
94 ath5k_hw_release_tx_queue(struct ath5k_hw *ah, unsigned int queue)
95 {
96 	if (WARN_ON(queue >= ah->ah_capabilities.cap_queues.q_tx_num))
97 		return;
98 
99 	/* This queue will be skipped in further operations */
100 	ah->ah_txq[queue].tqi_type = AR5K_TX_QUEUE_INACTIVE;
101 	/*For SIMR setup*/
102 	AR5K_Q_DISABLE_BITS(ah->ah_txq_status, queue);
103 }
104 
105 /**
106  * ath5k_cw_validate() - Make sure the given cw is valid
107  * @cw_req: The contention window value to check
108  *
109  * Make sure cw is a power of 2 minus 1 and smaller than 1024
110  */
111 static u16
112 ath5k_cw_validate(u16 cw_req)
113 {
114 	cw_req = min(cw_req, (u16)1023);
115 
116 	/* Check if cw_req + 1 a power of 2 */
117 	if (is_power_of_2(cw_req + 1))
118 		return cw_req;
119 
120 	/* Check if cw_req is a power of 2 */
121 	if (is_power_of_2(cw_req))
122 		return cw_req - 1;
123 
124 	/* If none of the above is correct
125 	 * find the closest power of 2 */
126 	cw_req = (u16) roundup_pow_of_two(cw_req) - 1;
127 
128 	return cw_req;
129 }
130 
131 /**
132  * ath5k_hw_get_tx_queueprops() - Get properties for a transmit queue
133  * @ah: The &struct ath5k_hw
134  * @queue: One of enum ath5k_tx_queue_id
135  * @queue_info: The &struct ath5k_txq_info to fill
136  */
137 int
138 ath5k_hw_get_tx_queueprops(struct ath5k_hw *ah, int queue,
139 		struct ath5k_txq_info *queue_info)
140 {
141 	memcpy(queue_info, &ah->ah_txq[queue], sizeof(struct ath5k_txq_info));
142 	return 0;
143 }
144 
145 /**
146  * ath5k_hw_set_tx_queueprops() - Set properties for a transmit queue
147  * @ah: The &struct ath5k_hw
148  * @queue: One of enum ath5k_tx_queue_id
149  * @qinfo: The &struct ath5k_txq_info to use
150  *
151  * Returns 0 on success or -EIO if queue is inactive
152  */
153 int
154 ath5k_hw_set_tx_queueprops(struct ath5k_hw *ah, int queue,
155 				const struct ath5k_txq_info *qinfo)
156 {
157 	struct ath5k_txq_info *qi;
158 
159 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
160 
161 	qi = &ah->ah_txq[queue];
162 
163 	if (qi->tqi_type == AR5K_TX_QUEUE_INACTIVE)
164 		return -EIO;
165 
166 	/* copy and validate values */
167 	qi->tqi_type = qinfo->tqi_type;
168 	qi->tqi_subtype = qinfo->tqi_subtype;
169 	qi->tqi_flags = qinfo->tqi_flags;
170 	/*
171 	 * According to the docs: Although the AIFS field is 8 bit wide,
172 	 * the maximum supported value is 0xFC. Setting it higher than that
173 	 * will cause the DCU to hang.
174 	 */
175 	qi->tqi_aifs = min(qinfo->tqi_aifs, (u8)0xFC);
176 	qi->tqi_cw_min = ath5k_cw_validate(qinfo->tqi_cw_min);
177 	qi->tqi_cw_max = ath5k_cw_validate(qinfo->tqi_cw_max);
178 	qi->tqi_cbr_period = qinfo->tqi_cbr_period;
179 	qi->tqi_cbr_overflow_limit = qinfo->tqi_cbr_overflow_limit;
180 	qi->tqi_burst_time = qinfo->tqi_burst_time;
181 	qi->tqi_ready_time = qinfo->tqi_ready_time;
182 
183 	/*XXX: Is this supported on 5210 ?*/
184 	/*XXX: Is this correct for AR5K_WME_AC_VI,VO ???*/
185 	if ((qinfo->tqi_type == AR5K_TX_QUEUE_DATA &&
186 		((qinfo->tqi_subtype == AR5K_WME_AC_VI) ||
187 		 (qinfo->tqi_subtype == AR5K_WME_AC_VO))) ||
188 	     qinfo->tqi_type == AR5K_TX_QUEUE_UAPSD)
189 		qi->tqi_flags |= AR5K_TXQ_FLAG_POST_FR_BKOFF_DIS;
190 
191 	return 0;
192 }
193 
194 /**
195  * ath5k_hw_setup_tx_queue() - Initialize a transmit queue
196  * @ah: The &struct ath5k_hw
197  * @queue_type: One of enum ath5k_tx_queue
198  * @queue_info: The &struct ath5k_txq_info to use
199  *
200  * Returns 0 on success, -EINVAL on invalid arguments
201  */
202 int
203 ath5k_hw_setup_tx_queue(struct ath5k_hw *ah, enum ath5k_tx_queue queue_type,
204 		struct ath5k_txq_info *queue_info)
205 {
206 	unsigned int queue;
207 	int ret;
208 
209 	/*
210 	 * Get queue by type
211 	 */
212 	/* 5210 only has 2 queues */
213 	if (ah->ah_capabilities.cap_queues.q_tx_num == 2) {
214 		switch (queue_type) {
215 		case AR5K_TX_QUEUE_DATA:
216 			queue = AR5K_TX_QUEUE_ID_NOQCU_DATA;
217 			break;
218 		case AR5K_TX_QUEUE_BEACON:
219 		case AR5K_TX_QUEUE_CAB:
220 			queue = AR5K_TX_QUEUE_ID_NOQCU_BEACON;
221 			break;
222 		default:
223 			return -EINVAL;
224 		}
225 	} else {
226 		switch (queue_type) {
227 		case AR5K_TX_QUEUE_DATA:
228 			queue = queue_info->tqi_subtype;
229 			break;
230 		case AR5K_TX_QUEUE_UAPSD:
231 			queue = AR5K_TX_QUEUE_ID_UAPSD;
232 			break;
233 		case AR5K_TX_QUEUE_BEACON:
234 			queue = AR5K_TX_QUEUE_ID_BEACON;
235 			break;
236 		case AR5K_TX_QUEUE_CAB:
237 			queue = AR5K_TX_QUEUE_ID_CAB;
238 			break;
239 		default:
240 			return -EINVAL;
241 		}
242 	}
243 
244 	/*
245 	 * Setup internal queue structure
246 	 */
247 	memset(&ah->ah_txq[queue], 0, sizeof(struct ath5k_txq_info));
248 	ah->ah_txq[queue].tqi_type = queue_type;
249 
250 	if (queue_info != NULL) {
251 		queue_info->tqi_type = queue_type;
252 		ret = ath5k_hw_set_tx_queueprops(ah, queue, queue_info);
253 		if (ret)
254 			return ret;
255 	}
256 
257 	/*
258 	 * We use ah_txq_status to hold a temp value for
259 	 * the Secondary interrupt mask registers on 5211+
260 	 * check out ath5k_hw_reset_tx_queue
261 	 */
262 	AR5K_Q_ENABLE_BITS(ah->ah_txq_status, queue);
263 
264 	return queue;
265 }
266 
267 
268 /*******************************\
269 * Single QCU/DCU initialization *
270 \*******************************/
271 
272 /**
273  * ath5k_hw_set_tx_retry_limits() - Set tx retry limits on DCU
274  * @ah: The &struct ath5k_hw
275  * @queue: One of enum ath5k_tx_queue_id
276  *
277  * This function is used when initializing a queue, to set
278  * retry limits based on ah->ah_retry_* and the chipset used.
279  */
280 void
281 ath5k_hw_set_tx_retry_limits(struct ath5k_hw *ah,
282 				  unsigned int queue)
283 {
284 	/* Single data queue on AR5210 */
285 	if (ah->ah_version == AR5K_AR5210) {
286 		struct ath5k_txq_info *tq = &ah->ah_txq[queue];
287 
288 		if (queue > 0)
289 			return;
290 
291 		ath5k_hw_reg_write(ah,
292 			(tq->tqi_cw_min << AR5K_NODCU_RETRY_LMT_CW_MIN_S)
293 			| AR5K_REG_SM(ah->ah_retry_long,
294 				      AR5K_NODCU_RETRY_LMT_SLG_RETRY)
295 			| AR5K_REG_SM(ah->ah_retry_short,
296 				      AR5K_NODCU_RETRY_LMT_SSH_RETRY)
297 			| AR5K_REG_SM(ah->ah_retry_long,
298 				      AR5K_NODCU_RETRY_LMT_LG_RETRY)
299 			| AR5K_REG_SM(ah->ah_retry_short,
300 				      AR5K_NODCU_RETRY_LMT_SH_RETRY),
301 			AR5K_NODCU_RETRY_LMT);
302 	/* DCU on AR5211+ */
303 	} else {
304 		ath5k_hw_reg_write(ah,
305 			AR5K_REG_SM(ah->ah_retry_long,
306 				    AR5K_DCU_RETRY_LMT_RTS)
307 			| AR5K_REG_SM(ah->ah_retry_long,
308 				      AR5K_DCU_RETRY_LMT_STA_RTS)
309 			| AR5K_REG_SM(max(ah->ah_retry_long, ah->ah_retry_short),
310 				      AR5K_DCU_RETRY_LMT_STA_DATA),
311 			AR5K_QUEUE_DFS_RETRY_LIMIT(queue));
312 	}
313 }
314 
315 /**
316  * ath5k_hw_reset_tx_queue() - Initialize a single hw queue
317  * @ah: The &struct ath5k_hw
318  * @queue: One of enum ath5k_tx_queue_id
319  *
320  * Set DCF properties for the given transmit queue on DCU
321  * and configures all queue-specific parameters.
322  */
323 int
324 ath5k_hw_reset_tx_queue(struct ath5k_hw *ah, unsigned int queue)
325 {
326 	struct ath5k_txq_info *tq = &ah->ah_txq[queue];
327 
328 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
329 
330 	tq = &ah->ah_txq[queue];
331 
332 	/* Skip if queue inactive or if we are on AR5210
333 	 * that doesn't have QCU/DCU */
334 	if ((ah->ah_version == AR5K_AR5210) ||
335 	(tq->tqi_type == AR5K_TX_QUEUE_INACTIVE))
336 		return 0;
337 
338 	/*
339 	 * Set contention window (cw_min/cw_max)
340 	 * and arbitrated interframe space (aifs)...
341 	 */
342 	ath5k_hw_reg_write(ah,
343 		AR5K_REG_SM(tq->tqi_cw_min, AR5K_DCU_LCL_IFS_CW_MIN) |
344 		AR5K_REG_SM(tq->tqi_cw_max, AR5K_DCU_LCL_IFS_CW_MAX) |
345 		AR5K_REG_SM(tq->tqi_aifs, AR5K_DCU_LCL_IFS_AIFS),
346 		AR5K_QUEUE_DFS_LOCAL_IFS(queue));
347 
348 	/*
349 	 * Set tx retry limits for this queue
350 	 */
351 	ath5k_hw_set_tx_retry_limits(ah, queue);
352 
353 
354 	/*
355 	 * Set misc registers
356 	 */
357 
358 	/* Enable DCU to wait for next fragment from QCU */
359 	AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_DFS_MISC(queue),
360 				AR5K_DCU_MISC_FRAG_WAIT);
361 
362 	/* On Maui and Spirit use the global seqnum on DCU */
363 	if (ah->ah_mac_version < AR5K_SREV_AR5211)
364 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_DFS_MISC(queue),
365 					AR5K_DCU_MISC_SEQNUM_CTL);
366 
367 	/* Constant bit rate period */
368 	if (tq->tqi_cbr_period) {
369 		ath5k_hw_reg_write(ah, AR5K_REG_SM(tq->tqi_cbr_period,
370 					AR5K_QCU_CBRCFG_INTVAL) |
371 					AR5K_REG_SM(tq->tqi_cbr_overflow_limit,
372 					AR5K_QCU_CBRCFG_ORN_THRES),
373 					AR5K_QUEUE_CBRCFG(queue));
374 
375 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
376 					AR5K_QCU_MISC_FRSHED_CBR);
377 
378 		if (tq->tqi_cbr_overflow_limit)
379 			AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
380 					AR5K_QCU_MISC_CBR_THRES_ENABLE);
381 	}
382 
383 	/* Ready time interval */
384 	if (tq->tqi_ready_time && (tq->tqi_type != AR5K_TX_QUEUE_CAB))
385 		ath5k_hw_reg_write(ah, AR5K_REG_SM(tq->tqi_ready_time,
386 					AR5K_QCU_RDYTIMECFG_INTVAL) |
387 					AR5K_QCU_RDYTIMECFG_ENABLE,
388 					AR5K_QUEUE_RDYTIMECFG(queue));
389 
390 	if (tq->tqi_burst_time) {
391 		ath5k_hw_reg_write(ah, AR5K_REG_SM(tq->tqi_burst_time,
392 					AR5K_DCU_CHAN_TIME_DUR) |
393 					AR5K_DCU_CHAN_TIME_ENABLE,
394 					AR5K_QUEUE_DFS_CHANNEL_TIME(queue));
395 
396 		if (tq->tqi_flags & AR5K_TXQ_FLAG_RDYTIME_EXP_POLICY_ENABLE)
397 			AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
398 					AR5K_QCU_MISC_RDY_VEOL_POLICY);
399 	}
400 
401 	/* Enable/disable Post frame backoff */
402 	if (tq->tqi_flags & AR5K_TXQ_FLAG_BACKOFF_DISABLE)
403 		ath5k_hw_reg_write(ah, AR5K_DCU_MISC_POST_FR_BKOFF_DIS,
404 					AR5K_QUEUE_DFS_MISC(queue));
405 
406 	/* Enable/disable fragmentation burst backoff */
407 	if (tq->tqi_flags & AR5K_TXQ_FLAG_FRAG_BURST_BACKOFF_ENABLE)
408 		ath5k_hw_reg_write(ah, AR5K_DCU_MISC_BACKOFF_FRAG,
409 					AR5K_QUEUE_DFS_MISC(queue));
410 
411 	/*
412 	 * Set registers by queue type
413 	 */
414 	switch (tq->tqi_type) {
415 	case AR5K_TX_QUEUE_BEACON:
416 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
417 				AR5K_QCU_MISC_FRSHED_DBA_GT |
418 				AR5K_QCU_MISC_CBREXP_BCN_DIS |
419 				AR5K_QCU_MISC_BCN_ENABLE);
420 
421 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_DFS_MISC(queue),
422 				(AR5K_DCU_MISC_ARBLOCK_CTL_GLOBAL <<
423 				AR5K_DCU_MISC_ARBLOCK_CTL_S) |
424 				AR5K_DCU_MISC_ARBLOCK_IGNORE |
425 				AR5K_DCU_MISC_POST_FR_BKOFF_DIS |
426 				AR5K_DCU_MISC_BCN_ENABLE);
427 		break;
428 
429 	case AR5K_TX_QUEUE_CAB:
430 		/* XXX: use BCN_SENT_GT, if we can figure out how */
431 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
432 					AR5K_QCU_MISC_FRSHED_DBA_GT |
433 					AR5K_QCU_MISC_CBREXP_DIS |
434 					AR5K_QCU_MISC_CBREXP_BCN_DIS);
435 
436 		ath5k_hw_reg_write(ah, ((tq->tqi_ready_time -
437 					(AR5K_TUNE_SW_BEACON_RESP -
438 					AR5K_TUNE_DMA_BEACON_RESP) -
439 				AR5K_TUNE_ADDITIONAL_SWBA_BACKOFF) * 1024) |
440 					AR5K_QCU_RDYTIMECFG_ENABLE,
441 					AR5K_QUEUE_RDYTIMECFG(queue));
442 
443 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_DFS_MISC(queue),
444 					(AR5K_DCU_MISC_ARBLOCK_CTL_GLOBAL <<
445 					AR5K_DCU_MISC_ARBLOCK_CTL_S));
446 		break;
447 
448 	case AR5K_TX_QUEUE_UAPSD:
449 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
450 					AR5K_QCU_MISC_CBREXP_DIS);
451 		break;
452 
453 	case AR5K_TX_QUEUE_DATA:
454 	default:
455 			break;
456 	}
457 
458 	/* TODO: Handle frame compression */
459 
460 	/*
461 	 * Enable interrupts for this tx queue
462 	 * in the secondary interrupt mask registers
463 	 */
464 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXOKINT_ENABLE)
465 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_txok, queue);
466 
467 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXERRINT_ENABLE)
468 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_txerr, queue);
469 
470 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXURNINT_ENABLE)
471 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_txurn, queue);
472 
473 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXDESCINT_ENABLE)
474 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_txdesc, queue);
475 
476 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXEOLINT_ENABLE)
477 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_txeol, queue);
478 
479 	if (tq->tqi_flags & AR5K_TXQ_FLAG_CBRORNINT_ENABLE)
480 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_cbrorn, queue);
481 
482 	if (tq->tqi_flags & AR5K_TXQ_FLAG_CBRURNINT_ENABLE)
483 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_cbrurn, queue);
484 
485 	if (tq->tqi_flags & AR5K_TXQ_FLAG_QTRIGINT_ENABLE)
486 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_qtrig, queue);
487 
488 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXNOFRMINT_ENABLE)
489 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_nofrm, queue);
490 
491 	/* Update secondary interrupt mask registers */
492 
493 	/* Filter out inactive queues */
494 	ah->ah_txq_imr_txok &= ah->ah_txq_status;
495 	ah->ah_txq_imr_txerr &= ah->ah_txq_status;
496 	ah->ah_txq_imr_txurn &= ah->ah_txq_status;
497 	ah->ah_txq_imr_txdesc &= ah->ah_txq_status;
498 	ah->ah_txq_imr_txeol &= ah->ah_txq_status;
499 	ah->ah_txq_imr_cbrorn &= ah->ah_txq_status;
500 	ah->ah_txq_imr_cbrurn &= ah->ah_txq_status;
501 	ah->ah_txq_imr_qtrig &= ah->ah_txq_status;
502 	ah->ah_txq_imr_nofrm &= ah->ah_txq_status;
503 
504 	ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txq_imr_txok,
505 					AR5K_SIMR0_QCU_TXOK) |
506 					AR5K_REG_SM(ah->ah_txq_imr_txdesc,
507 					AR5K_SIMR0_QCU_TXDESC),
508 					AR5K_SIMR0);
509 
510 	ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txq_imr_txerr,
511 					AR5K_SIMR1_QCU_TXERR) |
512 					AR5K_REG_SM(ah->ah_txq_imr_txeol,
513 					AR5K_SIMR1_QCU_TXEOL),
514 					AR5K_SIMR1);
515 
516 	/* Update SIMR2 but don't overwrite rest simr2 settings */
517 	AR5K_REG_DISABLE_BITS(ah, AR5K_SIMR2, AR5K_SIMR2_QCU_TXURN);
518 	AR5K_REG_ENABLE_BITS(ah, AR5K_SIMR2,
519 				AR5K_REG_SM(ah->ah_txq_imr_txurn,
520 				AR5K_SIMR2_QCU_TXURN));
521 
522 	ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txq_imr_cbrorn,
523 				AR5K_SIMR3_QCBRORN) |
524 				AR5K_REG_SM(ah->ah_txq_imr_cbrurn,
525 				AR5K_SIMR3_QCBRURN),
526 				AR5K_SIMR3);
527 
528 	ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txq_imr_qtrig,
529 				AR5K_SIMR4_QTRIG), AR5K_SIMR4);
530 
531 	/* Set TXNOFRM_QCU for the queues with TXNOFRM enabled */
532 	ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txq_imr_nofrm,
533 				AR5K_TXNOFRM_QCU), AR5K_TXNOFRM);
534 
535 	/* No queue has TXNOFRM enabled, disable the interrupt
536 	 * by setting AR5K_TXNOFRM to zero */
537 	if (ah->ah_txq_imr_nofrm == 0)
538 		ath5k_hw_reg_write(ah, 0, AR5K_TXNOFRM);
539 
540 	/* Set QCU mask for this DCU to save power */
541 	AR5K_REG_WRITE_Q(ah, AR5K_QUEUE_QCUMASK(queue), queue);
542 
543 	return 0;
544 }
545 
546 
547 /**************************\
548 * Global QCU/DCU functions *
549 \**************************/
550 
551 /**
552  * ath5k_hw_set_ifs_intervals()  - Set global inter-frame spaces on DCU
553  * @ah: The &struct ath5k_hw
554  * @slot_time: Slot time in us
555  *
556  * Sets the global IFS intervals on DCU (also works on AR5210) for
557  * the given slot time and the current bwmode.
558  */
559 int ath5k_hw_set_ifs_intervals(struct ath5k_hw *ah, unsigned int slot_time)
560 {
561 	struct ieee80211_channel *channel = ah->ah_current_channel;
562 	enum nl80211_band band;
563 	struct ieee80211_supported_band *sband;
564 	struct ieee80211_rate *rate;
565 	u32 ack_tx_time, eifs, eifs_clock, sifs, sifs_clock;
566 	u32 slot_time_clock = ath5k_hw_htoclock(ah, slot_time);
567 	u32 rate_flags, i;
568 
569 	if (slot_time < 6 || slot_time_clock > AR5K_SLOT_TIME_MAX)
570 		return -EINVAL;
571 
572 	sifs = ath5k_hw_get_default_sifs(ah);
573 	sifs_clock = ath5k_hw_htoclock(ah, sifs - 2);
574 
575 	/* EIFS
576 	 * Txtime of ack at lowest rate + SIFS + DIFS
577 	 * (DIFS = SIFS + 2 * Slot time)
578 	 *
579 	 * Note: HAL has some predefined values for EIFS
580 	 * Turbo:   (37 + 2 * 6)
581 	 * Default: (74 + 2 * 9)
582 	 * Half:    (149 + 2 * 13)
583 	 * Quarter: (298 + 2 * 21)
584 	 *
585 	 * (74 + 2 * 6) for AR5210 default and turbo !
586 	 *
587 	 * According to the formula we have
588 	 * ack_tx_time = 25 for turbo and
589 	 * ack_tx_time = 42.5 * clock multiplier
590 	 * for default/half/quarter.
591 	 *
592 	 * This can't be right, 42 is what we would get
593 	 * from ath5k_hw_get_frame_dur_for_bwmode or
594 	 * ieee80211_generic_frame_duration for zero frame
595 	 * length and without SIFS !
596 	 *
597 	 * Also we have different lowest rate for 802.11a
598 	 */
599 	if (channel->band == NL80211_BAND_5GHZ)
600 		band = NL80211_BAND_5GHZ;
601 	else
602 		band = NL80211_BAND_2GHZ;
603 
604 	switch (ah->ah_bwmode) {
605 	case AR5K_BWMODE_5MHZ:
606 		rate_flags = IEEE80211_RATE_SUPPORTS_5MHZ;
607 		break;
608 	case AR5K_BWMODE_10MHZ:
609 		rate_flags = IEEE80211_RATE_SUPPORTS_10MHZ;
610 		break;
611 	default:
612 		rate_flags = 0;
613 		break;
614 	}
615 	sband = &ah->sbands[band];
616 	rate = NULL;
617 	for (i = 0; i < sband->n_bitrates; i++) {
618 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
619 			continue;
620 		rate = &sband->bitrates[i];
621 		break;
622 	}
623 	if (WARN_ON(!rate))
624 		return -EINVAL;
625 
626 	ack_tx_time = ath5k_hw_get_frame_duration(ah, band, 10, rate, false);
627 
628 	/* ack_tx_time includes an SIFS already */
629 	eifs = ack_tx_time + sifs + 2 * slot_time;
630 	eifs_clock = ath5k_hw_htoclock(ah, eifs);
631 
632 	/* Set IFS settings on AR5210 */
633 	if (ah->ah_version == AR5K_AR5210) {
634 		u32 pifs, pifs_clock, difs, difs_clock;
635 
636 		/* Set slot time */
637 		ath5k_hw_reg_write(ah, slot_time_clock, AR5K_SLOT_TIME);
638 
639 		/* Set EIFS */
640 		eifs_clock = AR5K_REG_SM(eifs_clock, AR5K_IFS1_EIFS);
641 
642 		/* PIFS = Slot time + SIFS */
643 		pifs = slot_time + sifs;
644 		pifs_clock = ath5k_hw_htoclock(ah, pifs);
645 		pifs_clock = AR5K_REG_SM(pifs_clock, AR5K_IFS1_PIFS);
646 
647 		/* DIFS = SIFS + 2 * Slot time */
648 		difs = sifs + 2 * slot_time;
649 		difs_clock = ath5k_hw_htoclock(ah, difs);
650 
651 		/* Set SIFS/DIFS */
652 		ath5k_hw_reg_write(ah, (difs_clock <<
653 				AR5K_IFS0_DIFS_S) | sifs_clock,
654 				AR5K_IFS0);
655 
656 		/* Set PIFS/EIFS and preserve AR5K_INIT_CARR_SENSE_EN */
657 		ath5k_hw_reg_write(ah, pifs_clock | eifs_clock |
658 				(AR5K_INIT_CARR_SENSE_EN << AR5K_IFS1_CS_EN_S),
659 				AR5K_IFS1);
660 
661 		return 0;
662 	}
663 
664 	/* Set IFS slot time */
665 	ath5k_hw_reg_write(ah, slot_time_clock, AR5K_DCU_GBL_IFS_SLOT);
666 
667 	/* Set EIFS interval */
668 	ath5k_hw_reg_write(ah, eifs_clock, AR5K_DCU_GBL_IFS_EIFS);
669 
670 	/* Set SIFS interval in usecs */
671 	AR5K_REG_WRITE_BITS(ah, AR5K_DCU_GBL_IFS_MISC,
672 				AR5K_DCU_GBL_IFS_MISC_SIFS_DUR_USEC,
673 				sifs);
674 
675 	/* Set SIFS interval in clock cycles */
676 	ath5k_hw_reg_write(ah, sifs_clock, AR5K_DCU_GBL_IFS_SIFS);
677 
678 	return 0;
679 }
680 
681 
682 /**
683  * ath5k_hw_init_queues() - Initialize tx queues
684  * @ah: The &struct ath5k_hw
685  *
686  * Initializes all tx queues based on information on
687  * ah->ah_txq* set by the driver
688  */
689 int
690 ath5k_hw_init_queues(struct ath5k_hw *ah)
691 {
692 	int i, ret;
693 
694 	/* TODO: HW Compression support for data queues */
695 	/* TODO: Burst prefetch for data queues */
696 
697 	/*
698 	 * Reset queues and start beacon timers at the end of the reset routine
699 	 * This also sets QCU mask on each DCU for 1:1 qcu to dcu mapping
700 	 * Note: If we want we can assign multiple qcus on one dcu.
701 	 */
702 	if (ah->ah_version != AR5K_AR5210)
703 		for (i = 0; i < ah->ah_capabilities.cap_queues.q_tx_num; i++) {
704 			ret = ath5k_hw_reset_tx_queue(ah, i);
705 			if (ret) {
706 				ATH5K_ERR(ah,
707 					"failed to reset TX queue #%d\n", i);
708 				return ret;
709 			}
710 		}
711 	else
712 		/* No QCU/DCU on AR5210, just set tx
713 		 * retry limits. We set IFS parameters
714 		 * on ath5k_hw_set_ifs_intervals */
715 		ath5k_hw_set_tx_retry_limits(ah, 0);
716 
717 	/* Set the turbo flag when operating on 40MHz */
718 	if (ah->ah_bwmode == AR5K_BWMODE_40MHZ)
719 		AR5K_REG_ENABLE_BITS(ah, AR5K_DCU_GBL_IFS_MISC,
720 				AR5K_DCU_GBL_IFS_MISC_TURBO_MODE);
721 
722 	/* If we didn't set IFS timings through
723 	 * ath5k_hw_set_coverage_class make sure
724 	 * we set them here */
725 	if (!ah->ah_coverage_class) {
726 		unsigned int slot_time = ath5k_hw_get_default_slottime(ah);
727 		ath5k_hw_set_ifs_intervals(ah, slot_time);
728 	}
729 
730 	return 0;
731 }
732