xref: /openbmc/linux/drivers/net/wireless/ath/ath5k/qcu.c (revision 6c33a6f4)
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 	/* Skip if queue inactive or if we are on AR5210
331 	 * that doesn't have QCU/DCU */
332 	if ((ah->ah_version == AR5K_AR5210) ||
333 	(tq->tqi_type == AR5K_TX_QUEUE_INACTIVE))
334 		return 0;
335 
336 	/*
337 	 * Set contention window (cw_min/cw_max)
338 	 * and arbitrated interframe space (aifs)...
339 	 */
340 	ath5k_hw_reg_write(ah,
341 		AR5K_REG_SM(tq->tqi_cw_min, AR5K_DCU_LCL_IFS_CW_MIN) |
342 		AR5K_REG_SM(tq->tqi_cw_max, AR5K_DCU_LCL_IFS_CW_MAX) |
343 		AR5K_REG_SM(tq->tqi_aifs, AR5K_DCU_LCL_IFS_AIFS),
344 		AR5K_QUEUE_DFS_LOCAL_IFS(queue));
345 
346 	/*
347 	 * Set tx retry limits for this queue
348 	 */
349 	ath5k_hw_set_tx_retry_limits(ah, queue);
350 
351 
352 	/*
353 	 * Set misc registers
354 	 */
355 
356 	/* Enable DCU to wait for next fragment from QCU */
357 	AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_DFS_MISC(queue),
358 				AR5K_DCU_MISC_FRAG_WAIT);
359 
360 	/* On Maui and Spirit use the global seqnum on DCU */
361 	if (ah->ah_mac_version < AR5K_SREV_AR5211)
362 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_DFS_MISC(queue),
363 					AR5K_DCU_MISC_SEQNUM_CTL);
364 
365 	/* Constant bit rate period */
366 	if (tq->tqi_cbr_period) {
367 		ath5k_hw_reg_write(ah, AR5K_REG_SM(tq->tqi_cbr_period,
368 					AR5K_QCU_CBRCFG_INTVAL) |
369 					AR5K_REG_SM(tq->tqi_cbr_overflow_limit,
370 					AR5K_QCU_CBRCFG_ORN_THRES),
371 					AR5K_QUEUE_CBRCFG(queue));
372 
373 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
374 					AR5K_QCU_MISC_FRSHED_CBR);
375 
376 		if (tq->tqi_cbr_overflow_limit)
377 			AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
378 					AR5K_QCU_MISC_CBR_THRES_ENABLE);
379 	}
380 
381 	/* Ready time interval */
382 	if (tq->tqi_ready_time && (tq->tqi_type != AR5K_TX_QUEUE_CAB))
383 		ath5k_hw_reg_write(ah, AR5K_REG_SM(tq->tqi_ready_time,
384 					AR5K_QCU_RDYTIMECFG_INTVAL) |
385 					AR5K_QCU_RDYTIMECFG_ENABLE,
386 					AR5K_QUEUE_RDYTIMECFG(queue));
387 
388 	if (tq->tqi_burst_time) {
389 		ath5k_hw_reg_write(ah, AR5K_REG_SM(tq->tqi_burst_time,
390 					AR5K_DCU_CHAN_TIME_DUR) |
391 					AR5K_DCU_CHAN_TIME_ENABLE,
392 					AR5K_QUEUE_DFS_CHANNEL_TIME(queue));
393 
394 		if (tq->tqi_flags & AR5K_TXQ_FLAG_RDYTIME_EXP_POLICY_ENABLE)
395 			AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
396 					AR5K_QCU_MISC_RDY_VEOL_POLICY);
397 	}
398 
399 	/* Enable/disable Post frame backoff */
400 	if (tq->tqi_flags & AR5K_TXQ_FLAG_BACKOFF_DISABLE)
401 		ath5k_hw_reg_write(ah, AR5K_DCU_MISC_POST_FR_BKOFF_DIS,
402 					AR5K_QUEUE_DFS_MISC(queue));
403 
404 	/* Enable/disable fragmentation burst backoff */
405 	if (tq->tqi_flags & AR5K_TXQ_FLAG_FRAG_BURST_BACKOFF_ENABLE)
406 		ath5k_hw_reg_write(ah, AR5K_DCU_MISC_BACKOFF_FRAG,
407 					AR5K_QUEUE_DFS_MISC(queue));
408 
409 	/*
410 	 * Set registers by queue type
411 	 */
412 	switch (tq->tqi_type) {
413 	case AR5K_TX_QUEUE_BEACON:
414 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
415 				AR5K_QCU_MISC_FRSHED_DBA_GT |
416 				AR5K_QCU_MISC_CBREXP_BCN_DIS |
417 				AR5K_QCU_MISC_BCN_ENABLE);
418 
419 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_DFS_MISC(queue),
420 				(AR5K_DCU_MISC_ARBLOCK_CTL_GLOBAL <<
421 				AR5K_DCU_MISC_ARBLOCK_CTL_S) |
422 				AR5K_DCU_MISC_ARBLOCK_IGNORE |
423 				AR5K_DCU_MISC_POST_FR_BKOFF_DIS |
424 				AR5K_DCU_MISC_BCN_ENABLE);
425 		break;
426 
427 	case AR5K_TX_QUEUE_CAB:
428 		/* XXX: use BCN_SENT_GT, if we can figure out how */
429 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
430 					AR5K_QCU_MISC_FRSHED_DBA_GT |
431 					AR5K_QCU_MISC_CBREXP_DIS |
432 					AR5K_QCU_MISC_CBREXP_BCN_DIS);
433 
434 		ath5k_hw_reg_write(ah, ((tq->tqi_ready_time -
435 					(AR5K_TUNE_SW_BEACON_RESP -
436 					AR5K_TUNE_DMA_BEACON_RESP) -
437 				AR5K_TUNE_ADDITIONAL_SWBA_BACKOFF) * 1024) |
438 					AR5K_QCU_RDYTIMECFG_ENABLE,
439 					AR5K_QUEUE_RDYTIMECFG(queue));
440 
441 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_DFS_MISC(queue),
442 					(AR5K_DCU_MISC_ARBLOCK_CTL_GLOBAL <<
443 					AR5K_DCU_MISC_ARBLOCK_CTL_S));
444 		break;
445 
446 	case AR5K_TX_QUEUE_UAPSD:
447 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
448 					AR5K_QCU_MISC_CBREXP_DIS);
449 		break;
450 
451 	case AR5K_TX_QUEUE_DATA:
452 	default:
453 			break;
454 	}
455 
456 	/* TODO: Handle frame compression */
457 
458 	/*
459 	 * Enable interrupts for this tx queue
460 	 * in the secondary interrupt mask registers
461 	 */
462 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXOKINT_ENABLE)
463 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_txok, queue);
464 
465 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXERRINT_ENABLE)
466 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_txerr, queue);
467 
468 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXURNINT_ENABLE)
469 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_txurn, queue);
470 
471 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXDESCINT_ENABLE)
472 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_txdesc, queue);
473 
474 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXEOLINT_ENABLE)
475 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_txeol, queue);
476 
477 	if (tq->tqi_flags & AR5K_TXQ_FLAG_CBRORNINT_ENABLE)
478 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_cbrorn, queue);
479 
480 	if (tq->tqi_flags & AR5K_TXQ_FLAG_CBRURNINT_ENABLE)
481 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_cbrurn, queue);
482 
483 	if (tq->tqi_flags & AR5K_TXQ_FLAG_QTRIGINT_ENABLE)
484 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_qtrig, queue);
485 
486 	if (tq->tqi_flags & AR5K_TXQ_FLAG_TXNOFRMINT_ENABLE)
487 		AR5K_Q_ENABLE_BITS(ah->ah_txq_imr_nofrm, queue);
488 
489 	/* Update secondary interrupt mask registers */
490 
491 	/* Filter out inactive queues */
492 	ah->ah_txq_imr_txok &= ah->ah_txq_status;
493 	ah->ah_txq_imr_txerr &= ah->ah_txq_status;
494 	ah->ah_txq_imr_txurn &= ah->ah_txq_status;
495 	ah->ah_txq_imr_txdesc &= ah->ah_txq_status;
496 	ah->ah_txq_imr_txeol &= ah->ah_txq_status;
497 	ah->ah_txq_imr_cbrorn &= ah->ah_txq_status;
498 	ah->ah_txq_imr_cbrurn &= ah->ah_txq_status;
499 	ah->ah_txq_imr_qtrig &= ah->ah_txq_status;
500 	ah->ah_txq_imr_nofrm &= ah->ah_txq_status;
501 
502 	ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txq_imr_txok,
503 					AR5K_SIMR0_QCU_TXOK) |
504 					AR5K_REG_SM(ah->ah_txq_imr_txdesc,
505 					AR5K_SIMR0_QCU_TXDESC),
506 					AR5K_SIMR0);
507 
508 	ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txq_imr_txerr,
509 					AR5K_SIMR1_QCU_TXERR) |
510 					AR5K_REG_SM(ah->ah_txq_imr_txeol,
511 					AR5K_SIMR1_QCU_TXEOL),
512 					AR5K_SIMR1);
513 
514 	/* Update SIMR2 but don't overwrite rest simr2 settings */
515 	AR5K_REG_DISABLE_BITS(ah, AR5K_SIMR2, AR5K_SIMR2_QCU_TXURN);
516 	AR5K_REG_ENABLE_BITS(ah, AR5K_SIMR2,
517 				AR5K_REG_SM(ah->ah_txq_imr_txurn,
518 				AR5K_SIMR2_QCU_TXURN));
519 
520 	ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txq_imr_cbrorn,
521 				AR5K_SIMR3_QCBRORN) |
522 				AR5K_REG_SM(ah->ah_txq_imr_cbrurn,
523 				AR5K_SIMR3_QCBRURN),
524 				AR5K_SIMR3);
525 
526 	ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txq_imr_qtrig,
527 				AR5K_SIMR4_QTRIG), AR5K_SIMR4);
528 
529 	/* Set TXNOFRM_QCU for the queues with TXNOFRM enabled */
530 	ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txq_imr_nofrm,
531 				AR5K_TXNOFRM_QCU), AR5K_TXNOFRM);
532 
533 	/* No queue has TXNOFRM enabled, disable the interrupt
534 	 * by setting AR5K_TXNOFRM to zero */
535 	if (ah->ah_txq_imr_nofrm == 0)
536 		ath5k_hw_reg_write(ah, 0, AR5K_TXNOFRM);
537 
538 	/* Set QCU mask for this DCU to save power */
539 	AR5K_REG_WRITE_Q(ah, AR5K_QUEUE_QCUMASK(queue), queue);
540 
541 	return 0;
542 }
543 
544 
545 /**************************\
546 * Global QCU/DCU functions *
547 \**************************/
548 
549 /**
550  * ath5k_hw_set_ifs_intervals()  - Set global inter-frame spaces on DCU
551  * @ah: The &struct ath5k_hw
552  * @slot_time: Slot time in us
553  *
554  * Sets the global IFS intervals on DCU (also works on AR5210) for
555  * the given slot time and the current bwmode.
556  */
557 int ath5k_hw_set_ifs_intervals(struct ath5k_hw *ah, unsigned int slot_time)
558 {
559 	struct ieee80211_channel *channel = ah->ah_current_channel;
560 	enum nl80211_band band;
561 	struct ieee80211_supported_band *sband;
562 	struct ieee80211_rate *rate;
563 	u32 ack_tx_time, eifs, eifs_clock, sifs, sifs_clock;
564 	u32 slot_time_clock = ath5k_hw_htoclock(ah, slot_time);
565 	u32 rate_flags, i;
566 
567 	if (slot_time < 6 || slot_time_clock > AR5K_SLOT_TIME_MAX)
568 		return -EINVAL;
569 
570 	sifs = ath5k_hw_get_default_sifs(ah);
571 	sifs_clock = ath5k_hw_htoclock(ah, sifs - 2);
572 
573 	/* EIFS
574 	 * Txtime of ack at lowest rate + SIFS + DIFS
575 	 * (DIFS = SIFS + 2 * Slot time)
576 	 *
577 	 * Note: HAL has some predefined values for EIFS
578 	 * Turbo:   (37 + 2 * 6)
579 	 * Default: (74 + 2 * 9)
580 	 * Half:    (149 + 2 * 13)
581 	 * Quarter: (298 + 2 * 21)
582 	 *
583 	 * (74 + 2 * 6) for AR5210 default and turbo !
584 	 *
585 	 * According to the formula we have
586 	 * ack_tx_time = 25 for turbo and
587 	 * ack_tx_time = 42.5 * clock multiplier
588 	 * for default/half/quarter.
589 	 *
590 	 * This can't be right, 42 is what we would get
591 	 * from ath5k_hw_get_frame_dur_for_bwmode or
592 	 * ieee80211_generic_frame_duration for zero frame
593 	 * length and without SIFS !
594 	 *
595 	 * Also we have different lowest rate for 802.11a
596 	 */
597 	if (channel->band == NL80211_BAND_5GHZ)
598 		band = NL80211_BAND_5GHZ;
599 	else
600 		band = NL80211_BAND_2GHZ;
601 
602 	switch (ah->ah_bwmode) {
603 	case AR5K_BWMODE_5MHZ:
604 		rate_flags = IEEE80211_RATE_SUPPORTS_5MHZ;
605 		break;
606 	case AR5K_BWMODE_10MHZ:
607 		rate_flags = IEEE80211_RATE_SUPPORTS_10MHZ;
608 		break;
609 	default:
610 		rate_flags = 0;
611 		break;
612 	}
613 	sband = &ah->sbands[band];
614 	rate = NULL;
615 	for (i = 0; i < sband->n_bitrates; i++) {
616 		if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
617 			continue;
618 		rate = &sband->bitrates[i];
619 		break;
620 	}
621 	if (WARN_ON(!rate))
622 		return -EINVAL;
623 
624 	ack_tx_time = ath5k_hw_get_frame_duration(ah, band, 10, rate, false);
625 
626 	/* ack_tx_time includes an SIFS already */
627 	eifs = ack_tx_time + sifs + 2 * slot_time;
628 	eifs_clock = ath5k_hw_htoclock(ah, eifs);
629 
630 	/* Set IFS settings on AR5210 */
631 	if (ah->ah_version == AR5K_AR5210) {
632 		u32 pifs, pifs_clock, difs, difs_clock;
633 
634 		/* Set slot time */
635 		ath5k_hw_reg_write(ah, slot_time_clock, AR5K_SLOT_TIME);
636 
637 		/* Set EIFS */
638 		eifs_clock = AR5K_REG_SM(eifs_clock, AR5K_IFS1_EIFS);
639 
640 		/* PIFS = Slot time + SIFS */
641 		pifs = slot_time + sifs;
642 		pifs_clock = ath5k_hw_htoclock(ah, pifs);
643 		pifs_clock = AR5K_REG_SM(pifs_clock, AR5K_IFS1_PIFS);
644 
645 		/* DIFS = SIFS + 2 * Slot time */
646 		difs = sifs + 2 * slot_time;
647 		difs_clock = ath5k_hw_htoclock(ah, difs);
648 
649 		/* Set SIFS/DIFS */
650 		ath5k_hw_reg_write(ah, (difs_clock <<
651 				AR5K_IFS0_DIFS_S) | sifs_clock,
652 				AR5K_IFS0);
653 
654 		/* Set PIFS/EIFS and preserve AR5K_INIT_CARR_SENSE_EN */
655 		ath5k_hw_reg_write(ah, pifs_clock | eifs_clock |
656 				(AR5K_INIT_CARR_SENSE_EN << AR5K_IFS1_CS_EN_S),
657 				AR5K_IFS1);
658 
659 		return 0;
660 	}
661 
662 	/* Set IFS slot time */
663 	ath5k_hw_reg_write(ah, slot_time_clock, AR5K_DCU_GBL_IFS_SLOT);
664 
665 	/* Set EIFS interval */
666 	ath5k_hw_reg_write(ah, eifs_clock, AR5K_DCU_GBL_IFS_EIFS);
667 
668 	/* Set SIFS interval in usecs */
669 	AR5K_REG_WRITE_BITS(ah, AR5K_DCU_GBL_IFS_MISC,
670 				AR5K_DCU_GBL_IFS_MISC_SIFS_DUR_USEC,
671 				sifs);
672 
673 	/* Set SIFS interval in clock cycles */
674 	ath5k_hw_reg_write(ah, sifs_clock, AR5K_DCU_GBL_IFS_SIFS);
675 
676 	return 0;
677 }
678 
679 
680 /**
681  * ath5k_hw_init_queues() - Initialize tx queues
682  * @ah: The &struct ath5k_hw
683  *
684  * Initializes all tx queues based on information on
685  * ah->ah_txq* set by the driver
686  */
687 int
688 ath5k_hw_init_queues(struct ath5k_hw *ah)
689 {
690 	int i, ret;
691 
692 	/* TODO: HW Compression support for data queues */
693 	/* TODO: Burst prefetch for data queues */
694 
695 	/*
696 	 * Reset queues and start beacon timers at the end of the reset routine
697 	 * This also sets QCU mask on each DCU for 1:1 qcu to dcu mapping
698 	 * Note: If we want we can assign multiple qcus on one dcu.
699 	 */
700 	if (ah->ah_version != AR5K_AR5210)
701 		for (i = 0; i < ah->ah_capabilities.cap_queues.q_tx_num; i++) {
702 			ret = ath5k_hw_reset_tx_queue(ah, i);
703 			if (ret) {
704 				ATH5K_ERR(ah,
705 					"failed to reset TX queue #%d\n", i);
706 				return ret;
707 			}
708 		}
709 	else
710 		/* No QCU/DCU on AR5210, just set tx
711 		 * retry limits. We set IFS parameters
712 		 * on ath5k_hw_set_ifs_intervals */
713 		ath5k_hw_set_tx_retry_limits(ah, 0);
714 
715 	/* Set the turbo flag when operating on 40MHz */
716 	if (ah->ah_bwmode == AR5K_BWMODE_40MHZ)
717 		AR5K_REG_ENABLE_BITS(ah, AR5K_DCU_GBL_IFS_MISC,
718 				AR5K_DCU_GBL_IFS_MISC_TURBO_MODE);
719 
720 	/* If we didn't set IFS timings through
721 	 * ath5k_hw_set_coverage_class make sure
722 	 * we set them here */
723 	if (!ah->ah_coverage_class) {
724 		unsigned int slot_time = ath5k_hw_get_default_slottime(ah);
725 		ath5k_hw_set_ifs_intervals(ah, slot_time);
726 	}
727 
728 	return 0;
729 }
730