xref: /linux/drivers/net/wireless/ath/ath5k/dma.c (revision e0d687bd)
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 * DMA and interrupt masking functions *
21 \*************************************/
22 
23 /*
24  * dma.c - DMA and interrupt masking functions
25  *
26  * Here we setup descriptor pointers (rxdp/txdp) start/stop dma engine and
27  * handle queue setup for 5210 chipset (rest are handled on qcu.c).
28  * Also we setup interrupt mask register (IMR) and read the various interrupt
29  * status registers (ISR).
30  *
31  * TODO: Handle SISR on 5211+ and introduce a function to return the queue
32  * number that resulted the interrupt.
33  */
34 
35 #include "ath5k.h"
36 #include "reg.h"
37 #include "debug.h"
38 #include "base.h"
39 
40 
41 /*********\
42 * Receive *
43 \*********/
44 
45 /**
46  * ath5k_hw_start_rx_dma - Start DMA receive
47  *
48  * @ah:	The &struct ath5k_hw
49  */
50 void ath5k_hw_start_rx_dma(struct ath5k_hw *ah)
51 {
52 	ath5k_hw_reg_write(ah, AR5K_CR_RXE, AR5K_CR);
53 	ath5k_hw_reg_read(ah, AR5K_CR);
54 }
55 
56 /**
57  * ath5k_hw_stop_rx_dma - Stop DMA receive
58  *
59  * @ah:	The &struct ath5k_hw
60  */
61 static int ath5k_hw_stop_rx_dma(struct ath5k_hw *ah)
62 {
63 	unsigned int i;
64 
65 	ath5k_hw_reg_write(ah, AR5K_CR_RXD, AR5K_CR);
66 
67 	/*
68 	 * It may take some time to disable the DMA receive unit
69 	 */
70 	for (i = 1000; i > 0 &&
71 			(ath5k_hw_reg_read(ah, AR5K_CR) & AR5K_CR_RXE) != 0;
72 			i--)
73 		udelay(100);
74 
75 	if (!i)
76 		ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
77 				"failed to stop RX DMA !\n");
78 
79 	return i ? 0 : -EBUSY;
80 }
81 
82 /**
83  * ath5k_hw_get_rxdp - Get RX Descriptor's address
84  *
85  * @ah: The &struct ath5k_hw
86  */
87 u32 ath5k_hw_get_rxdp(struct ath5k_hw *ah)
88 {
89 	return ath5k_hw_reg_read(ah, AR5K_RXDP);
90 }
91 
92 /**
93  * ath5k_hw_set_rxdp - Set RX Descriptor's address
94  *
95  * @ah: The &struct ath5k_hw
96  * @phys_addr: RX descriptor address
97  *
98  * Returns -EIO if rx is active
99  */
100 int ath5k_hw_set_rxdp(struct ath5k_hw *ah, u32 phys_addr)
101 {
102 	if (ath5k_hw_reg_read(ah, AR5K_CR) & AR5K_CR_RXE) {
103 		ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
104 				"tried to set RXDP while rx was active !\n");
105 		return -EIO;
106 	}
107 
108 	ath5k_hw_reg_write(ah, phys_addr, AR5K_RXDP);
109 	return 0;
110 }
111 
112 
113 /**********\
114 * Transmit *
115 \**********/
116 
117 /**
118  * ath5k_hw_start_tx_dma - Start DMA transmit for a specific queue
119  *
120  * @ah: The &struct ath5k_hw
121  * @queue: The hw queue number
122  *
123  * Start DMA transmit for a specific queue and since 5210 doesn't have
124  * QCU/DCU, set up queue parameters for 5210 here based on queue type (one
125  * queue for normal data and one queue for beacons). For queue setup
126  * on newer chips check out qcu.c. Returns -EINVAL if queue number is out
127  * of range or if queue is already disabled.
128  *
129  * NOTE: Must be called after setting up tx control descriptor for that
130  * queue (see below).
131  */
132 int ath5k_hw_start_tx_dma(struct ath5k_hw *ah, unsigned int queue)
133 {
134 	u32 tx_queue;
135 
136 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
137 
138 	/* Return if queue is declared inactive */
139 	if (ah->ah_txq[queue].tqi_type == AR5K_TX_QUEUE_INACTIVE)
140 		return -EINVAL;
141 
142 	if (ah->ah_version == AR5K_AR5210) {
143 		tx_queue = ath5k_hw_reg_read(ah, AR5K_CR);
144 
145 		/*
146 		 * Set the queue by type on 5210
147 		 */
148 		switch (ah->ah_txq[queue].tqi_type) {
149 		case AR5K_TX_QUEUE_DATA:
150 			tx_queue |= AR5K_CR_TXE0 & ~AR5K_CR_TXD0;
151 			break;
152 		case AR5K_TX_QUEUE_BEACON:
153 			tx_queue |= AR5K_CR_TXE1 & ~AR5K_CR_TXD1;
154 			ath5k_hw_reg_write(ah, AR5K_BCR_TQ1V | AR5K_BCR_BDMAE,
155 					AR5K_BSR);
156 			break;
157 		case AR5K_TX_QUEUE_CAB:
158 			tx_queue |= AR5K_CR_TXE1 & ~AR5K_CR_TXD1;
159 			ath5k_hw_reg_write(ah, AR5K_BCR_TQ1FV | AR5K_BCR_TQ1V |
160 				AR5K_BCR_BDMAE, AR5K_BSR);
161 			break;
162 		default:
163 			return -EINVAL;
164 		}
165 		/* Start queue */
166 		ath5k_hw_reg_write(ah, tx_queue, AR5K_CR);
167 		ath5k_hw_reg_read(ah, AR5K_CR);
168 	} else {
169 		/* Return if queue is disabled */
170 		if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXD, queue))
171 			return -EIO;
172 
173 		/* Start queue */
174 		AR5K_REG_WRITE_Q(ah, AR5K_QCU_TXE, queue);
175 	}
176 
177 	return 0;
178 }
179 
180 /**
181  * ath5k_hw_stop_tx_dma - Stop DMA transmit on a specific queue
182  *
183  * @ah: The &struct ath5k_hw
184  * @queue: The hw queue number
185  *
186  * Stop DMA transmit on a specific hw queue and drain queue so we don't
187  * have any pending frames. Returns -EBUSY if we still have pending frames,
188  * -EINVAL if queue number is out of range or inactive.
189  *
190  */
191 static int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
192 {
193 	unsigned int i = 40;
194 	u32 tx_queue, pending;
195 
196 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
197 
198 	/* Return if queue is declared inactive */
199 	if (ah->ah_txq[queue].tqi_type == AR5K_TX_QUEUE_INACTIVE)
200 		return -EINVAL;
201 
202 	if (ah->ah_version == AR5K_AR5210) {
203 		tx_queue = ath5k_hw_reg_read(ah, AR5K_CR);
204 
205 		/*
206 		 * Set by queue type
207 		 */
208 		switch (ah->ah_txq[queue].tqi_type) {
209 		case AR5K_TX_QUEUE_DATA:
210 			tx_queue |= AR5K_CR_TXD0 & ~AR5K_CR_TXE0;
211 			break;
212 		case AR5K_TX_QUEUE_BEACON:
213 		case AR5K_TX_QUEUE_CAB:
214 			/* XXX Fix me... */
215 			tx_queue |= AR5K_CR_TXD1 & ~AR5K_CR_TXD1;
216 			ath5k_hw_reg_write(ah, 0, AR5K_BSR);
217 			break;
218 		default:
219 			return -EINVAL;
220 		}
221 
222 		/* Stop queue */
223 		ath5k_hw_reg_write(ah, tx_queue, AR5K_CR);
224 		ath5k_hw_reg_read(ah, AR5K_CR);
225 	} else {
226 
227 		/*
228 		 * Enable DCU early termination to quickly
229 		 * flush any pending frames from QCU
230 		 */
231 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
232 					AR5K_QCU_MISC_DCU_EARLY);
233 
234 		/*
235 		 * Schedule TX disable and wait until queue is empty
236 		 */
237 		AR5K_REG_WRITE_Q(ah, AR5K_QCU_TXD, queue);
238 
239 		/* Wait for queue to stop */
240 		for (i = 1000; i > 0 &&
241 		(AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue) != 0);
242 		i--)
243 			udelay(100);
244 
245 		if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue))
246 			ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
247 				"queue %i didn't stop !\n", queue);
248 
249 		/* Check for pending frames */
250 		i = 1000;
251 		do {
252 			pending = ath5k_hw_reg_read(ah,
253 				AR5K_QUEUE_STATUS(queue)) &
254 				AR5K_QCU_STS_FRMPENDCNT;
255 			udelay(100);
256 		} while (--i && pending);
257 
258 		/* For 2413+ order PCU to drop packets using
259 		 * QUIET mechanism */
260 		if (ah->ah_mac_version >= (AR5K_SREV_AR2414 >> 4) &&
261 		    pending) {
262 			/* Set periodicity and duration */
263 			ath5k_hw_reg_write(ah,
264 				AR5K_REG_SM(100, AR5K_QUIET_CTL2_QT_PER)|
265 				AR5K_REG_SM(10, AR5K_QUIET_CTL2_QT_DUR),
266 				AR5K_QUIET_CTL2);
267 
268 			/* Enable quiet period for current TSF */
269 			ath5k_hw_reg_write(ah,
270 				AR5K_QUIET_CTL1_QT_EN |
271 				AR5K_REG_SM(ath5k_hw_reg_read(ah,
272 						AR5K_TSF_L32_5211) >> 10,
273 						AR5K_QUIET_CTL1_NEXT_QT_TSF),
274 				AR5K_QUIET_CTL1);
275 
276 			/* Force channel idle high */
277 			AR5K_REG_ENABLE_BITS(ah, AR5K_DIAG_SW_5211,
278 					AR5K_DIAG_SW_CHANNEL_IDLE_HIGH);
279 
280 			/* Wait a while and disable mechanism */
281 			udelay(400);
282 			AR5K_REG_DISABLE_BITS(ah, AR5K_QUIET_CTL1,
283 						AR5K_QUIET_CTL1_QT_EN);
284 
285 			/* Re-check for pending frames */
286 			i = 100;
287 			do {
288 				pending = ath5k_hw_reg_read(ah,
289 					AR5K_QUEUE_STATUS(queue)) &
290 					AR5K_QCU_STS_FRMPENDCNT;
291 				udelay(100);
292 			} while (--i && pending);
293 
294 			AR5K_REG_DISABLE_BITS(ah, AR5K_DIAG_SW_5211,
295 					AR5K_DIAG_SW_CHANNEL_IDLE_HIGH);
296 
297 			if (pending)
298 				ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
299 					"quiet mechanism didn't work q:%i !\n",
300 					queue);
301 		}
302 
303 		/*
304 		 * Disable DCU early termination
305 		 */
306 		AR5K_REG_DISABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
307 					AR5K_QCU_MISC_DCU_EARLY);
308 
309 		/* Clear register */
310 		ath5k_hw_reg_write(ah, 0, AR5K_QCU_TXD);
311 		if (pending) {
312 			ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
313 					"tx dma didn't stop (q:%i, frm:%i) !\n",
314 					queue, pending);
315 			return -EBUSY;
316 		}
317 	}
318 
319 	/* TODO: Check for success on 5210 else return error */
320 	return 0;
321 }
322 
323 /**
324  * ath5k_hw_stop_beacon_queue - Stop beacon queue
325  *
326  * @ah The &struct ath5k_hw
327  * @queue The queue number
328  *
329  * Returns -EIO if queue didn't stop
330  */
331 int ath5k_hw_stop_beacon_queue(struct ath5k_hw *ah, unsigned int queue)
332 {
333 	int ret;
334 	ret = ath5k_hw_stop_tx_dma(ah, queue);
335 	if (ret) {
336 		ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
337 				"beacon queue didn't stop !\n");
338 		return -EIO;
339 	}
340 	return 0;
341 }
342 
343 /**
344  * ath5k_hw_get_txdp - Get TX Descriptor's address for a specific queue
345  *
346  * @ah: The &struct ath5k_hw
347  * @queue: The hw queue number
348  *
349  * Get TX descriptor's address for a specific queue. For 5210 we ignore
350  * the queue number and use tx queue type since we only have 2 queues.
351  * We use TXDP0 for normal data queue and TXDP1 for beacon queue.
352  * For newer chips with QCU/DCU we just read the corresponding TXDP register.
353  *
354  * XXX: Is TXDP read and clear ?
355  */
356 u32 ath5k_hw_get_txdp(struct ath5k_hw *ah, unsigned int queue)
357 {
358 	u16 tx_reg;
359 
360 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
361 
362 	/*
363 	 * Get the transmit queue descriptor pointer from the selected queue
364 	 */
365 	/*5210 doesn't have QCU*/
366 	if (ah->ah_version == AR5K_AR5210) {
367 		switch (ah->ah_txq[queue].tqi_type) {
368 		case AR5K_TX_QUEUE_DATA:
369 			tx_reg = AR5K_NOQCU_TXDP0;
370 			break;
371 		case AR5K_TX_QUEUE_BEACON:
372 		case AR5K_TX_QUEUE_CAB:
373 			tx_reg = AR5K_NOQCU_TXDP1;
374 			break;
375 		default:
376 			return 0xffffffff;
377 		}
378 	} else {
379 		tx_reg = AR5K_QUEUE_TXDP(queue);
380 	}
381 
382 	return ath5k_hw_reg_read(ah, tx_reg);
383 }
384 
385 /**
386  * ath5k_hw_set_txdp - Set TX Descriptor's address for a specific queue
387  *
388  * @ah: The &struct ath5k_hw
389  * @queue: The hw queue number
390  *
391  * Set TX descriptor's address for a specific queue. For 5210 we ignore
392  * the queue number and we use tx queue type since we only have 2 queues
393  * so as above we use TXDP0 for normal data queue and TXDP1 for beacon queue.
394  * For newer chips with QCU/DCU we just set the corresponding TXDP register.
395  * Returns -EINVAL if queue type is invalid for 5210 and -EIO if queue is still
396  * active.
397  */
398 int ath5k_hw_set_txdp(struct ath5k_hw *ah, unsigned int queue, u32 phys_addr)
399 {
400 	u16 tx_reg;
401 
402 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
403 
404 	/*
405 	 * Set the transmit queue descriptor pointer register by type
406 	 * on 5210
407 	 */
408 	if (ah->ah_version == AR5K_AR5210) {
409 		switch (ah->ah_txq[queue].tqi_type) {
410 		case AR5K_TX_QUEUE_DATA:
411 			tx_reg = AR5K_NOQCU_TXDP0;
412 			break;
413 		case AR5K_TX_QUEUE_BEACON:
414 		case AR5K_TX_QUEUE_CAB:
415 			tx_reg = AR5K_NOQCU_TXDP1;
416 			break;
417 		default:
418 			return -EINVAL;
419 		}
420 	} else {
421 		/*
422 		 * Set the transmit queue descriptor pointer for
423 		 * the selected queue on QCU for 5211+
424 		 * (this won't work if the queue is still active)
425 		 */
426 		if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue))
427 			return -EIO;
428 
429 		tx_reg = AR5K_QUEUE_TXDP(queue);
430 	}
431 
432 	/* Set descriptor pointer */
433 	ath5k_hw_reg_write(ah, phys_addr, tx_reg);
434 
435 	return 0;
436 }
437 
438 /**
439  * ath5k_hw_update_tx_triglevel - Update tx trigger level
440  *
441  * @ah: The &struct ath5k_hw
442  * @increase: Flag to force increase of trigger level
443  *
444  * This function increases/decreases the tx trigger level for the tx fifo
445  * buffer (aka FIFO threshold) that is used to indicate when PCU flushes
446  * the buffer and transmits its data. Lowering this results sending small
447  * frames more quickly but can lead to tx underruns, raising it a lot can
448  * result other problems (i think bmiss is related). Right now we start with
449  * the lowest possible (64Bytes) and if we get tx underrun we increase it using
450  * the increase flag. Returns -EIO if we have reached maximum/minimum.
451  *
452  * XXX: Link this with tx DMA size ?
453  * XXX: Use it to save interrupts ?
454  * TODO: Needs testing, i think it's related to bmiss...
455  */
456 int ath5k_hw_update_tx_triglevel(struct ath5k_hw *ah, bool increase)
457 {
458 	u32 trigger_level, imr;
459 	int ret = -EIO;
460 
461 	/*
462 	 * Disable interrupts by setting the mask
463 	 */
464 	imr = ath5k_hw_set_imr(ah, ah->ah_imr & ~AR5K_INT_GLOBAL);
465 
466 	trigger_level = AR5K_REG_MS(ath5k_hw_reg_read(ah, AR5K_TXCFG),
467 			AR5K_TXCFG_TXFULL);
468 
469 	if (!increase) {
470 		if (--trigger_level < AR5K_TUNE_MIN_TX_FIFO_THRES)
471 			goto done;
472 	} else
473 		trigger_level +=
474 			((AR5K_TUNE_MAX_TX_FIFO_THRES - trigger_level) / 2);
475 
476 	/*
477 	 * Update trigger level on success
478 	 */
479 	if (ah->ah_version == AR5K_AR5210)
480 		ath5k_hw_reg_write(ah, trigger_level, AR5K_TRIG_LVL);
481 	else
482 		AR5K_REG_WRITE_BITS(ah, AR5K_TXCFG,
483 				AR5K_TXCFG_TXFULL, trigger_level);
484 
485 	ret = 0;
486 
487 done:
488 	/*
489 	 * Restore interrupt mask
490 	 */
491 	ath5k_hw_set_imr(ah, imr);
492 
493 	return ret;
494 }
495 
496 
497 /*******************\
498 * Interrupt masking *
499 \*******************/
500 
501 /**
502  * ath5k_hw_is_intr_pending - Check if we have pending interrupts
503  *
504  * @ah: The &struct ath5k_hw
505  *
506  * Check if we have pending interrupts to process. Returns 1 if we
507  * have pending interrupts and 0 if we haven't.
508  */
509 bool ath5k_hw_is_intr_pending(struct ath5k_hw *ah)
510 {
511 	return ath5k_hw_reg_read(ah, AR5K_INTPEND) == 1 ? 1 : 0;
512 }
513 
514 /**
515  * ath5k_hw_get_isr - Get interrupt status
516  *
517  * @ah: The @struct ath5k_hw
518  * @interrupt_mask: Driver's interrupt mask used to filter out
519  * interrupts in sw.
520  *
521  * This function is used inside our interrupt handler to determine the reason
522  * for the interrupt by reading Primary Interrupt Status Register. Returns an
523  * abstract interrupt status mask which is mostly ISR with some uncommon bits
524  * being mapped on some standard non hw-specific positions
525  * (check out &ath5k_int).
526  *
527  * NOTE: We use read-and-clear register, so after this function is called ISR
528  * is zeroed.
529  */
530 int ath5k_hw_get_isr(struct ath5k_hw *ah, enum ath5k_int *interrupt_mask)
531 {
532 	u32 data;
533 
534 	/*
535 	 * Read interrupt status from the Interrupt Status register
536 	 * on 5210
537 	 */
538 	if (ah->ah_version == AR5K_AR5210) {
539 		data = ath5k_hw_reg_read(ah, AR5K_ISR);
540 		if (unlikely(data == AR5K_INT_NOCARD)) {
541 			*interrupt_mask = data;
542 			return -ENODEV;
543 		}
544 	} else {
545 		/*
546 		 * Read interrupt status from Interrupt
547 		 * Status Register shadow copy (Read And Clear)
548 		 *
549 		 * Note: PISR/SISR Not available on 5210
550 		 */
551 		data = ath5k_hw_reg_read(ah, AR5K_RAC_PISR);
552 		if (unlikely(data == AR5K_INT_NOCARD)) {
553 			*interrupt_mask = data;
554 			return -ENODEV;
555 		}
556 	}
557 
558 	/*
559 	 * Get abstract interrupt mask (driver-compatible)
560 	 */
561 	*interrupt_mask = (data & AR5K_INT_COMMON) & ah->ah_imr;
562 
563 	if (ah->ah_version != AR5K_AR5210) {
564 		u32 sisr2 = ath5k_hw_reg_read(ah, AR5K_RAC_SISR2);
565 
566 		/*HIU = Host Interface Unit (PCI etc)*/
567 		if (unlikely(data & (AR5K_ISR_HIUERR)))
568 			*interrupt_mask |= AR5K_INT_FATAL;
569 
570 		/*Beacon Not Ready*/
571 		if (unlikely(data & (AR5K_ISR_BNR)))
572 			*interrupt_mask |= AR5K_INT_BNR;
573 
574 		if (unlikely(sisr2 & (AR5K_SISR2_SSERR |
575 					AR5K_SISR2_DPERR |
576 					AR5K_SISR2_MCABT)))
577 			*interrupt_mask |= AR5K_INT_FATAL;
578 
579 		if (data & AR5K_ISR_TIM)
580 			*interrupt_mask |= AR5K_INT_TIM;
581 
582 		if (data & AR5K_ISR_BCNMISC) {
583 			if (sisr2 & AR5K_SISR2_TIM)
584 				*interrupt_mask |= AR5K_INT_TIM;
585 			if (sisr2 & AR5K_SISR2_DTIM)
586 				*interrupt_mask |= AR5K_INT_DTIM;
587 			if (sisr2 & AR5K_SISR2_DTIM_SYNC)
588 				*interrupt_mask |= AR5K_INT_DTIM_SYNC;
589 			if (sisr2 & AR5K_SISR2_BCN_TIMEOUT)
590 				*interrupt_mask |= AR5K_INT_BCN_TIMEOUT;
591 			if (sisr2 & AR5K_SISR2_CAB_TIMEOUT)
592 				*interrupt_mask |= AR5K_INT_CAB_TIMEOUT;
593 		}
594 
595 		if (data & AR5K_ISR_RXDOPPLER)
596 			*interrupt_mask |= AR5K_INT_RX_DOPPLER;
597 		if (data & AR5K_ISR_QCBRORN) {
598 			*interrupt_mask |= AR5K_INT_QCBRORN;
599 			ah->ah_txq_isr |= AR5K_REG_MS(
600 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR3),
601 					AR5K_SISR3_QCBRORN);
602 		}
603 		if (data & AR5K_ISR_QCBRURN) {
604 			*interrupt_mask |= AR5K_INT_QCBRURN;
605 			ah->ah_txq_isr |= AR5K_REG_MS(
606 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR3),
607 					AR5K_SISR3_QCBRURN);
608 		}
609 		if (data & AR5K_ISR_QTRIG) {
610 			*interrupt_mask |= AR5K_INT_QTRIG;
611 			ah->ah_txq_isr |= AR5K_REG_MS(
612 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR4),
613 					AR5K_SISR4_QTRIG);
614 		}
615 
616 		if (data & AR5K_ISR_TXOK)
617 			ah->ah_txq_isr |= AR5K_REG_MS(
618 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR0),
619 					AR5K_SISR0_QCU_TXOK);
620 
621 		if (data & AR5K_ISR_TXDESC)
622 			ah->ah_txq_isr |= AR5K_REG_MS(
623 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR0),
624 					AR5K_SISR0_QCU_TXDESC);
625 
626 		if (data & AR5K_ISR_TXERR)
627 			ah->ah_txq_isr |= AR5K_REG_MS(
628 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR1),
629 					AR5K_SISR1_QCU_TXERR);
630 
631 		if (data & AR5K_ISR_TXEOL)
632 			ah->ah_txq_isr |= AR5K_REG_MS(
633 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR1),
634 					AR5K_SISR1_QCU_TXEOL);
635 
636 		if (data & AR5K_ISR_TXURN)
637 			ah->ah_txq_isr |= AR5K_REG_MS(
638 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR2),
639 					AR5K_SISR2_QCU_TXURN);
640 	} else {
641 		if (unlikely(data & (AR5K_ISR_SSERR | AR5K_ISR_MCABT
642 				| AR5K_ISR_HIUERR | AR5K_ISR_DPERR)))
643 			*interrupt_mask |= AR5K_INT_FATAL;
644 
645 		/*
646 		 * XXX: BMISS interrupts may occur after association.
647 		 * I found this on 5210 code but it needs testing. If this is
648 		 * true we should disable them before assoc and re-enable them
649 		 * after a successful assoc + some jiffies.
650 			interrupt_mask &= ~AR5K_INT_BMISS;
651 		 */
652 	}
653 
654 	/*
655 	 * In case we didn't handle anything,
656 	 * print the register value.
657 	 */
658 	if (unlikely(*interrupt_mask == 0 && net_ratelimit()))
659 		ATH5K_PRINTF("ISR: 0x%08x IMR: 0x%08x\n", data, ah->ah_imr);
660 
661 	return 0;
662 }
663 
664 /**
665  * ath5k_hw_set_imr - Set interrupt mask
666  *
667  * @ah: The &struct ath5k_hw
668  * @new_mask: The new interrupt mask to be set
669  *
670  * Set the interrupt mask in hw to save interrupts. We do that by mapping
671  * ath5k_int bits to hw-specific bits to remove abstraction and writing
672  * Interrupt Mask Register.
673  */
674 enum ath5k_int ath5k_hw_set_imr(struct ath5k_hw *ah, enum ath5k_int new_mask)
675 {
676 	enum ath5k_int old_mask, int_mask;
677 
678 	old_mask = ah->ah_imr;
679 
680 	/*
681 	 * Disable card interrupts to prevent any race conditions
682 	 * (they will be re-enabled afterwards if AR5K_INT GLOBAL
683 	 * is set again on the new mask).
684 	 */
685 	if (old_mask & AR5K_INT_GLOBAL) {
686 		ath5k_hw_reg_write(ah, AR5K_IER_DISABLE, AR5K_IER);
687 		ath5k_hw_reg_read(ah, AR5K_IER);
688 	}
689 
690 	/*
691 	 * Add additional, chipset-dependent interrupt mask flags
692 	 * and write them to the IMR (interrupt mask register).
693 	 */
694 	int_mask = new_mask & AR5K_INT_COMMON;
695 
696 	if (ah->ah_version != AR5K_AR5210) {
697 		/* Preserve per queue TXURN interrupt mask */
698 		u32 simr2 = ath5k_hw_reg_read(ah, AR5K_SIMR2)
699 				& AR5K_SIMR2_QCU_TXURN;
700 
701 		if (new_mask & AR5K_INT_FATAL) {
702 			int_mask |= AR5K_IMR_HIUERR;
703 			simr2 |= (AR5K_SIMR2_MCABT | AR5K_SIMR2_SSERR
704 				| AR5K_SIMR2_DPERR);
705 		}
706 
707 		/*Beacon Not Ready*/
708 		if (new_mask & AR5K_INT_BNR)
709 			int_mask |= AR5K_INT_BNR;
710 
711 		if (new_mask & AR5K_INT_TIM)
712 			int_mask |= AR5K_IMR_TIM;
713 
714 		if (new_mask & AR5K_INT_TIM)
715 			simr2 |= AR5K_SISR2_TIM;
716 		if (new_mask & AR5K_INT_DTIM)
717 			simr2 |= AR5K_SISR2_DTIM;
718 		if (new_mask & AR5K_INT_DTIM_SYNC)
719 			simr2 |= AR5K_SISR2_DTIM_SYNC;
720 		if (new_mask & AR5K_INT_BCN_TIMEOUT)
721 			simr2 |= AR5K_SISR2_BCN_TIMEOUT;
722 		if (new_mask & AR5K_INT_CAB_TIMEOUT)
723 			simr2 |= AR5K_SISR2_CAB_TIMEOUT;
724 
725 		if (new_mask & AR5K_INT_RX_DOPPLER)
726 			int_mask |= AR5K_IMR_RXDOPPLER;
727 
728 		/* Note: Per queue interrupt masks
729 		 * are set via ath5k_hw_reset_tx_queue() (qcu.c) */
730 		ath5k_hw_reg_write(ah, int_mask, AR5K_PIMR);
731 		ath5k_hw_reg_write(ah, simr2, AR5K_SIMR2);
732 
733 	} else {
734 		if (new_mask & AR5K_INT_FATAL)
735 			int_mask |= (AR5K_IMR_SSERR | AR5K_IMR_MCABT
736 				| AR5K_IMR_HIUERR | AR5K_IMR_DPERR);
737 
738 		ath5k_hw_reg_write(ah, int_mask, AR5K_IMR);
739 	}
740 
741 	/* If RXNOFRM interrupt is masked disable it
742 	 * by setting AR5K_RXNOFRM to zero */
743 	if (!(new_mask & AR5K_INT_RXNOFRM))
744 		ath5k_hw_reg_write(ah, 0, AR5K_RXNOFRM);
745 
746 	/* Store new interrupt mask */
747 	ah->ah_imr = new_mask;
748 
749 	/* ..re-enable interrupts if AR5K_INT_GLOBAL is set */
750 	if (new_mask & AR5K_INT_GLOBAL) {
751 		ath5k_hw_reg_write(ah, AR5K_IER_ENABLE, AR5K_IER);
752 		ath5k_hw_reg_read(ah, AR5K_IER);
753 	}
754 
755 	return old_mask;
756 }
757 
758 
759 /********************\
760  Init/Stop functions
761 \********************/
762 
763 /**
764  * ath5k_hw_dma_init - Initialize DMA unit
765  *
766  * @ah: The &struct ath5k_hw
767  *
768  * Set DMA size and pre-enable interrupts
769  * (driver handles tx/rx buffer setup and
770  * dma start/stop)
771  *
772  * XXX: Save/restore RXDP/TXDP registers ?
773  */
774 void ath5k_hw_dma_init(struct ath5k_hw *ah)
775 {
776 	/*
777 	 * Set Rx/Tx DMA Configuration
778 	 *
779 	 * Set standard DMA size (128). Note that
780 	 * a DMA size of 512 causes rx overruns and tx errors
781 	 * on pci-e cards (tested on 5424 but since rx overruns
782 	 * also occur on 5416/5418 with madwifi we set 128
783 	 * for all PCI-E cards to be safe).
784 	 *
785 	 * XXX: need to check 5210 for this
786 	 * TODO: Check out tx trigger level, it's always 64 on dumps but I
787 	 * guess we can tweak it and see how it goes ;-)
788 	 */
789 	if (ah->ah_version != AR5K_AR5210) {
790 		AR5K_REG_WRITE_BITS(ah, AR5K_TXCFG,
791 			AR5K_TXCFG_SDMAMR, AR5K_DMASIZE_128B);
792 		AR5K_REG_WRITE_BITS(ah, AR5K_RXCFG,
793 			AR5K_RXCFG_SDMAMW, AR5K_DMASIZE_128B);
794 	}
795 
796 	/* Pre-enable interrupts on 5211/5212*/
797 	if (ah->ah_version != AR5K_AR5210)
798 		ath5k_hw_set_imr(ah, ah->ah_imr);
799 
800 }
801 
802 /**
803  * ath5k_hw_dma_stop - stop DMA unit
804  *
805  * @ah: The &struct ath5k_hw
806  *
807  * Stop tx/rx DMA and interrupts. Returns
808  * -EBUSY if tx or rx dma failed to stop.
809  *
810  * XXX: Sometimes DMA unit hangs and we have
811  * stuck frames on tx queues, only a reset
812  * can fix that.
813  */
814 int ath5k_hw_dma_stop(struct ath5k_hw *ah)
815 {
816 	int i, qmax, err;
817 	err = 0;
818 
819 	/* Disable interrupts */
820 	ath5k_hw_set_imr(ah, 0);
821 
822 	/* Stop rx dma */
823 	err = ath5k_hw_stop_rx_dma(ah);
824 	if (err)
825 		return err;
826 
827 	/* Clear any pending interrupts
828 	 * and disable tx dma */
829 	if (ah->ah_version != AR5K_AR5210) {
830 		ath5k_hw_reg_write(ah, 0xffffffff, AR5K_PISR);
831 		qmax = AR5K_NUM_TX_QUEUES;
832 	} else {
833 		/* PISR/SISR Not available on 5210 */
834 		ath5k_hw_reg_read(ah, AR5K_ISR);
835 		qmax = AR5K_NUM_TX_QUEUES_NOQCU;
836 	}
837 
838 	for (i = 0; i < qmax; i++) {
839 		err = ath5k_hw_stop_tx_dma(ah, i);
840 		/* -EINVAL -> queue inactive */
841 		if (err && err != -EINVAL)
842 			return err;
843 	}
844 
845 	return 0;
846 }
847