xref: /linux/drivers/net/wireless/ath/ath5k/dma.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
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 
39 
40 /*********\
41 * Receive *
42 \*********/
43 
44 /**
45  * ath5k_hw_start_rx_dma - Start DMA receive
46  *
47  * @ah:	The &struct ath5k_hw
48  */
49 void ath5k_hw_start_rx_dma(struct ath5k_hw *ah)
50 {
51 	ath5k_hw_reg_write(ah, AR5K_CR_RXE, AR5K_CR);
52 	ath5k_hw_reg_read(ah, AR5K_CR);
53 }
54 
55 /**
56  * ath5k_hw_stop_rx_dma - Stop DMA receive
57  *
58  * @ah:	The &struct ath5k_hw
59  */
60 static int ath5k_hw_stop_rx_dma(struct ath5k_hw *ah)
61 {
62 	unsigned int i;
63 
64 	ath5k_hw_reg_write(ah, AR5K_CR_RXD, AR5K_CR);
65 
66 	/*
67 	 * It may take some time to disable the DMA receive unit
68 	 */
69 	for (i = 1000; i > 0 &&
70 			(ath5k_hw_reg_read(ah, AR5K_CR) & AR5K_CR_RXE) != 0;
71 			i--)
72 		udelay(100);
73 
74 	if (!i)
75 		ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
76 				"failed to stop RX DMA !\n");
77 
78 	return i ? 0 : -EBUSY;
79 }
80 
81 /**
82  * ath5k_hw_get_rxdp - Get RX Descriptor's address
83  *
84  * @ah: The &struct ath5k_hw
85  */
86 u32 ath5k_hw_get_rxdp(struct ath5k_hw *ah)
87 {
88 	return ath5k_hw_reg_read(ah, AR5K_RXDP);
89 }
90 
91 /**
92  * ath5k_hw_set_rxdp - Set RX Descriptor's address
93  *
94  * @ah: The &struct ath5k_hw
95  * @phys_addr: RX descriptor address
96  *
97  * Returns -EIO if rx is active
98  */
99 int ath5k_hw_set_rxdp(struct ath5k_hw *ah, u32 phys_addr)
100 {
101 	if (ath5k_hw_reg_read(ah, AR5K_CR) & AR5K_CR_RXE) {
102 		ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
103 				"tried to set RXDP while rx was active !\n");
104 		return -EIO;
105 	}
106 
107 	ath5k_hw_reg_write(ah, phys_addr, AR5K_RXDP);
108 	return 0;
109 }
110 
111 
112 /**********\
113 * Transmit *
114 \**********/
115 
116 /**
117  * ath5k_hw_start_tx_dma - Start DMA transmit for a specific queue
118  *
119  * @ah: The &struct ath5k_hw
120  * @queue: The hw queue number
121  *
122  * Start DMA transmit for a specific queue and since 5210 doesn't have
123  * QCU/DCU, set up queue parameters for 5210 here based on queue type (one
124  * queue for normal data and one queue for beacons). For queue setup
125  * on newer chips check out qcu.c. Returns -EINVAL if queue number is out
126  * of range or if queue is already disabled.
127  *
128  * NOTE: Must be called after setting up tx control descriptor for that
129  * queue (see below).
130  */
131 int ath5k_hw_start_tx_dma(struct ath5k_hw *ah, unsigned int queue)
132 {
133 	u32 tx_queue;
134 
135 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
136 
137 	/* Return if queue is declared inactive */
138 	if (ah->ah_txq[queue].tqi_type == AR5K_TX_QUEUE_INACTIVE)
139 		return -EINVAL;
140 
141 	if (ah->ah_version == AR5K_AR5210) {
142 		tx_queue = ath5k_hw_reg_read(ah, AR5K_CR);
143 
144 		/*
145 		 * Set the queue by type on 5210
146 		 */
147 		switch (ah->ah_txq[queue].tqi_type) {
148 		case AR5K_TX_QUEUE_DATA:
149 			tx_queue |= AR5K_CR_TXE0 & ~AR5K_CR_TXD0;
150 			break;
151 		case AR5K_TX_QUEUE_BEACON:
152 			tx_queue |= AR5K_CR_TXE1 & ~AR5K_CR_TXD1;
153 			ath5k_hw_reg_write(ah, AR5K_BCR_TQ1V | AR5K_BCR_BDMAE,
154 					AR5K_BSR);
155 			break;
156 		case AR5K_TX_QUEUE_CAB:
157 			tx_queue |= AR5K_CR_TXE1 & ~AR5K_CR_TXD1;
158 			ath5k_hw_reg_write(ah, AR5K_BCR_TQ1FV | AR5K_BCR_TQ1V |
159 				AR5K_BCR_BDMAE, AR5K_BSR);
160 			break;
161 		default:
162 			return -EINVAL;
163 		}
164 		/* Start queue */
165 		ath5k_hw_reg_write(ah, tx_queue, AR5K_CR);
166 		ath5k_hw_reg_read(ah, AR5K_CR);
167 	} else {
168 		/* Return if queue is disabled */
169 		if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXD, queue))
170 			return -EIO;
171 
172 		/* Start queue */
173 		AR5K_REG_WRITE_Q(ah, AR5K_QCU_TXE, queue);
174 	}
175 
176 	return 0;
177 }
178 
179 /**
180  * ath5k_hw_stop_tx_dma - Stop DMA transmit on a specific queue
181  *
182  * @ah: The &struct ath5k_hw
183  * @queue: The hw queue number
184  *
185  * Stop DMA transmit on a specific hw queue and drain queue so we don't
186  * have any pending frames. Returns -EBUSY if we still have pending frames,
187  * -EINVAL if queue number is out of range or inactive.
188  *
189  */
190 static int ath5k_hw_stop_tx_dma(struct ath5k_hw *ah, unsigned int queue)
191 {
192 	unsigned int i = 40;
193 	u32 tx_queue, pending;
194 
195 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
196 
197 	/* Return if queue is declared inactive */
198 	if (ah->ah_txq[queue].tqi_type == AR5K_TX_QUEUE_INACTIVE)
199 		return -EINVAL;
200 
201 	if (ah->ah_version == AR5K_AR5210) {
202 		tx_queue = ath5k_hw_reg_read(ah, AR5K_CR);
203 
204 		/*
205 		 * Set by queue type
206 		 */
207 		switch (ah->ah_txq[queue].tqi_type) {
208 		case AR5K_TX_QUEUE_DATA:
209 			tx_queue |= AR5K_CR_TXD0 & ~AR5K_CR_TXE0;
210 			break;
211 		case AR5K_TX_QUEUE_BEACON:
212 		case AR5K_TX_QUEUE_CAB:
213 			/* XXX Fix me... */
214 			tx_queue |= AR5K_CR_TXD1 & ~AR5K_CR_TXD1;
215 			ath5k_hw_reg_write(ah, 0, AR5K_BSR);
216 			break;
217 		default:
218 			return -EINVAL;
219 		}
220 
221 		/* Stop queue */
222 		ath5k_hw_reg_write(ah, tx_queue, AR5K_CR);
223 		ath5k_hw_reg_read(ah, AR5K_CR);
224 	} else {
225 
226 		/*
227 		 * Enable DCU early termination to quickly
228 		 * flush any pending frames from QCU
229 		 */
230 		AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
231 					AR5K_QCU_MISC_DCU_EARLY);
232 
233 		/*
234 		 * Schedule TX disable and wait until queue is empty
235 		 */
236 		AR5K_REG_WRITE_Q(ah, AR5K_QCU_TXD, queue);
237 
238 		/* Wait for queue to stop */
239 		for (i = 1000; i > 0 &&
240 		(AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue) != 0);
241 		i--)
242 			udelay(100);
243 
244 		if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue))
245 			ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
246 				"queue %i didn't stop !\n", queue);
247 
248 		/* Check for pending frames */
249 		i = 1000;
250 		do {
251 			pending = ath5k_hw_reg_read(ah,
252 				AR5K_QUEUE_STATUS(queue)) &
253 				AR5K_QCU_STS_FRMPENDCNT;
254 			udelay(100);
255 		} while (--i && pending);
256 
257 		/* For 2413+ order PCU to drop packets using
258 		 * QUIET mechanism */
259 		if (ah->ah_mac_version >= (AR5K_SREV_AR2414 >> 4) &&
260 		    pending) {
261 			/* Set periodicity and duration */
262 			ath5k_hw_reg_write(ah,
263 				AR5K_REG_SM(100, AR5K_QUIET_CTL2_QT_PER)|
264 				AR5K_REG_SM(10, AR5K_QUIET_CTL2_QT_DUR),
265 				AR5K_QUIET_CTL2);
266 
267 			/* Enable quiet period for current TSF */
268 			ath5k_hw_reg_write(ah,
269 				AR5K_QUIET_CTL1_QT_EN |
270 				AR5K_REG_SM(ath5k_hw_reg_read(ah,
271 						AR5K_TSF_L32_5211) >> 10,
272 						AR5K_QUIET_CTL1_NEXT_QT_TSF),
273 				AR5K_QUIET_CTL1);
274 
275 			/* Force channel idle high */
276 			AR5K_REG_ENABLE_BITS(ah, AR5K_DIAG_SW_5211,
277 					AR5K_DIAG_SW_CHANNEL_IDLE_HIGH);
278 
279 			/* Wait a while and disable mechanism */
280 			udelay(400);
281 			AR5K_REG_DISABLE_BITS(ah, AR5K_QUIET_CTL1,
282 						AR5K_QUIET_CTL1_QT_EN);
283 
284 			/* Re-check for pending frames */
285 			i = 100;
286 			do {
287 				pending = ath5k_hw_reg_read(ah,
288 					AR5K_QUEUE_STATUS(queue)) &
289 					AR5K_QCU_STS_FRMPENDCNT;
290 				udelay(100);
291 			} while (--i && pending);
292 
293 			AR5K_REG_DISABLE_BITS(ah, AR5K_DIAG_SW_5211,
294 					AR5K_DIAG_SW_CHANNEL_IDLE_HIGH);
295 
296 			if (pending)
297 				ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
298 					"quiet mechanism didn't work q:%i !\n",
299 					queue);
300 		}
301 
302 		/*
303 		 * Disable DCU early termination
304 		 */
305 		AR5K_REG_DISABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
306 					AR5K_QCU_MISC_DCU_EARLY);
307 
308 		/* Clear register */
309 		ath5k_hw_reg_write(ah, 0, AR5K_QCU_TXD);
310 		if (pending) {
311 			ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
312 					"tx dma didn't stop (q:%i, frm:%i) !\n",
313 					queue, pending);
314 			return -EBUSY;
315 		}
316 	}
317 
318 	/* TODO: Check for success on 5210 else return error */
319 	return 0;
320 }
321 
322 /**
323  * ath5k_hw_stop_beacon_queue - Stop beacon queue
324  *
325  * @ah The &struct ath5k_hw
326  * @queue The queue number
327  *
328  * Returns -EIO if queue didn't stop
329  */
330 int ath5k_hw_stop_beacon_queue(struct ath5k_hw *ah, unsigned int queue)
331 {
332 	int ret;
333 	ret = ath5k_hw_stop_tx_dma(ah, queue);
334 	if (ret) {
335 		ATH5K_DBG(ah, ATH5K_DEBUG_DMA,
336 				"beacon queue didn't stop !\n");
337 		return -EIO;
338 	}
339 	return 0;
340 }
341 
342 /**
343  * ath5k_hw_get_txdp - Get TX Descriptor's address for a specific queue
344  *
345  * @ah: The &struct ath5k_hw
346  * @queue: The hw queue number
347  *
348  * Get TX descriptor's address for a specific queue. For 5210 we ignore
349  * the queue number and use tx queue type since we only have 2 queues.
350  * We use TXDP0 for normal data queue and TXDP1 for beacon queue.
351  * For newer chips with QCU/DCU we just read the corresponding TXDP register.
352  *
353  * XXX: Is TXDP read and clear ?
354  */
355 u32 ath5k_hw_get_txdp(struct ath5k_hw *ah, unsigned int queue)
356 {
357 	u16 tx_reg;
358 
359 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
360 
361 	/*
362 	 * Get the transmit queue descriptor pointer from the selected queue
363 	 */
364 	/*5210 doesn't have QCU*/
365 	if (ah->ah_version == AR5K_AR5210) {
366 		switch (ah->ah_txq[queue].tqi_type) {
367 		case AR5K_TX_QUEUE_DATA:
368 			tx_reg = AR5K_NOQCU_TXDP0;
369 			break;
370 		case AR5K_TX_QUEUE_BEACON:
371 		case AR5K_TX_QUEUE_CAB:
372 			tx_reg = AR5K_NOQCU_TXDP1;
373 			break;
374 		default:
375 			return 0xffffffff;
376 		}
377 	} else {
378 		tx_reg = AR5K_QUEUE_TXDP(queue);
379 	}
380 
381 	return ath5k_hw_reg_read(ah, tx_reg);
382 }
383 
384 /**
385  * ath5k_hw_set_txdp - Set TX Descriptor's address for a specific queue
386  *
387  * @ah: The &struct ath5k_hw
388  * @queue: The hw queue number
389  *
390  * Set TX descriptor's address for a specific queue. For 5210 we ignore
391  * the queue number and we use tx queue type since we only have 2 queues
392  * so as above we use TXDP0 for normal data queue and TXDP1 for beacon queue.
393  * For newer chips with QCU/DCU we just set the corresponding TXDP register.
394  * Returns -EINVAL if queue type is invalid for 5210 and -EIO if queue is still
395  * active.
396  */
397 int ath5k_hw_set_txdp(struct ath5k_hw *ah, unsigned int queue, u32 phys_addr)
398 {
399 	u16 tx_reg;
400 
401 	AR5K_ASSERT_ENTRY(queue, ah->ah_capabilities.cap_queues.q_tx_num);
402 
403 	/*
404 	 * Set the transmit queue descriptor pointer register by type
405 	 * on 5210
406 	 */
407 	if (ah->ah_version == AR5K_AR5210) {
408 		switch (ah->ah_txq[queue].tqi_type) {
409 		case AR5K_TX_QUEUE_DATA:
410 			tx_reg = AR5K_NOQCU_TXDP0;
411 			break;
412 		case AR5K_TX_QUEUE_BEACON:
413 		case AR5K_TX_QUEUE_CAB:
414 			tx_reg = AR5K_NOQCU_TXDP1;
415 			break;
416 		default:
417 			return -EINVAL;
418 		}
419 	} else {
420 		/*
421 		 * Set the transmit queue descriptor pointer for
422 		 * the selected queue on QCU for 5211+
423 		 * (this won't work if the queue is still active)
424 		 */
425 		if (AR5K_REG_READ_Q(ah, AR5K_QCU_TXE, queue))
426 			return -EIO;
427 
428 		tx_reg = AR5K_QUEUE_TXDP(queue);
429 	}
430 
431 	/* Set descriptor pointer */
432 	ath5k_hw_reg_write(ah, phys_addr, tx_reg);
433 
434 	return 0;
435 }
436 
437 /**
438  * ath5k_hw_update_tx_triglevel - Update tx trigger level
439  *
440  * @ah: The &struct ath5k_hw
441  * @increase: Flag to force increase of trigger level
442  *
443  * This function increases/decreases the tx trigger level for the tx fifo
444  * buffer (aka FIFO threshold) that is used to indicate when PCU flushes
445  * the buffer and transmits its data. Lowering this results sending small
446  * frames more quickly but can lead to tx underruns, raising it a lot can
447  * result other problems (i think bmiss is related). Right now we start with
448  * the lowest possible (64Bytes) and if we get tx underrun we increase it using
449  * the increase flag. Returns -EIO if we have reached maximum/minimum.
450  *
451  * XXX: Link this with tx DMA size ?
452  * XXX: Use it to save interrupts ?
453  * TODO: Needs testing, i think it's related to bmiss...
454  */
455 int ath5k_hw_update_tx_triglevel(struct ath5k_hw *ah, bool increase)
456 {
457 	u32 trigger_level, imr;
458 	int ret = -EIO;
459 
460 	/*
461 	 * Disable interrupts by setting the mask
462 	 */
463 	imr = ath5k_hw_set_imr(ah, ah->ah_imr & ~AR5K_INT_GLOBAL);
464 
465 	trigger_level = AR5K_REG_MS(ath5k_hw_reg_read(ah, AR5K_TXCFG),
466 			AR5K_TXCFG_TXFULL);
467 
468 	if (!increase) {
469 		if (--trigger_level < AR5K_TUNE_MIN_TX_FIFO_THRES)
470 			goto done;
471 	} else
472 		trigger_level +=
473 			((AR5K_TUNE_MAX_TX_FIFO_THRES - trigger_level) / 2);
474 
475 	/*
476 	 * Update trigger level on success
477 	 */
478 	if (ah->ah_version == AR5K_AR5210)
479 		ath5k_hw_reg_write(ah, trigger_level, AR5K_TRIG_LVL);
480 	else
481 		AR5K_REG_WRITE_BITS(ah, AR5K_TXCFG,
482 				AR5K_TXCFG_TXFULL, trigger_level);
483 
484 	ret = 0;
485 
486 done:
487 	/*
488 	 * Restore interrupt mask
489 	 */
490 	ath5k_hw_set_imr(ah, imr);
491 
492 	return ret;
493 }
494 
495 
496 /*******************\
497 * Interrupt masking *
498 \*******************/
499 
500 /**
501  * ath5k_hw_is_intr_pending - Check if we have pending interrupts
502  *
503  * @ah: The &struct ath5k_hw
504  *
505  * Check if we have pending interrupts to process. Returns 1 if we
506  * have pending interrupts and 0 if we haven't.
507  */
508 bool ath5k_hw_is_intr_pending(struct ath5k_hw *ah)
509 {
510 	return ath5k_hw_reg_read(ah, AR5K_INTPEND) == 1 ? 1 : 0;
511 }
512 
513 /**
514  * ath5k_hw_get_isr - Get interrupt status
515  *
516  * @ah: The @struct ath5k_hw
517  * @interrupt_mask: Driver's interrupt mask used to filter out
518  * interrupts in sw.
519  *
520  * This function is used inside our interrupt handler to determine the reason
521  * for the interrupt by reading Primary Interrupt Status Register. Returns an
522  * abstract interrupt status mask which is mostly ISR with some uncommon bits
523  * being mapped on some standard non hw-specific positions
524  * (check out &ath5k_int).
525  *
526  * NOTE: We use read-and-clear register, so after this function is called ISR
527  * is zeroed.
528  */
529 int ath5k_hw_get_isr(struct ath5k_hw *ah, enum ath5k_int *interrupt_mask)
530 {
531 	u32 data;
532 
533 	/*
534 	 * Read interrupt status from the Interrupt Status register
535 	 * on 5210
536 	 */
537 	if (ah->ah_version == AR5K_AR5210) {
538 		data = ath5k_hw_reg_read(ah, AR5K_ISR);
539 		if (unlikely(data == AR5K_INT_NOCARD)) {
540 			*interrupt_mask = data;
541 			return -ENODEV;
542 		}
543 	} else {
544 		/*
545 		 * Read interrupt status from Interrupt
546 		 * Status Register shadow copy (Read And Clear)
547 		 *
548 		 * Note: PISR/SISR Not available on 5210
549 		 */
550 		data = ath5k_hw_reg_read(ah, AR5K_RAC_PISR);
551 		if (unlikely(data == AR5K_INT_NOCARD)) {
552 			*interrupt_mask = data;
553 			return -ENODEV;
554 		}
555 	}
556 
557 	/*
558 	 * Get abstract interrupt mask (driver-compatible)
559 	 */
560 	*interrupt_mask = (data & AR5K_INT_COMMON) & ah->ah_imr;
561 
562 	if (ah->ah_version != AR5K_AR5210) {
563 		u32 sisr2 = ath5k_hw_reg_read(ah, AR5K_RAC_SISR2);
564 
565 		/*HIU = Host Interface Unit (PCI etc)*/
566 		if (unlikely(data & (AR5K_ISR_HIUERR)))
567 			*interrupt_mask |= AR5K_INT_FATAL;
568 
569 		/*Beacon Not Ready*/
570 		if (unlikely(data & (AR5K_ISR_BNR)))
571 			*interrupt_mask |= AR5K_INT_BNR;
572 
573 		if (unlikely(sisr2 & (AR5K_SISR2_SSERR |
574 					AR5K_SISR2_DPERR |
575 					AR5K_SISR2_MCABT)))
576 			*interrupt_mask |= AR5K_INT_FATAL;
577 
578 		if (data & AR5K_ISR_TIM)
579 			*interrupt_mask |= AR5K_INT_TIM;
580 
581 		if (data & AR5K_ISR_BCNMISC) {
582 			if (sisr2 & AR5K_SISR2_TIM)
583 				*interrupt_mask |= AR5K_INT_TIM;
584 			if (sisr2 & AR5K_SISR2_DTIM)
585 				*interrupt_mask |= AR5K_INT_DTIM;
586 			if (sisr2 & AR5K_SISR2_DTIM_SYNC)
587 				*interrupt_mask |= AR5K_INT_DTIM_SYNC;
588 			if (sisr2 & AR5K_SISR2_BCN_TIMEOUT)
589 				*interrupt_mask |= AR5K_INT_BCN_TIMEOUT;
590 			if (sisr2 & AR5K_SISR2_CAB_TIMEOUT)
591 				*interrupt_mask |= AR5K_INT_CAB_TIMEOUT;
592 		}
593 
594 		if (data & AR5K_ISR_RXDOPPLER)
595 			*interrupt_mask |= AR5K_INT_RX_DOPPLER;
596 		if (data & AR5K_ISR_QCBRORN) {
597 			*interrupt_mask |= AR5K_INT_QCBRORN;
598 			ah->ah_txq_isr |= AR5K_REG_MS(
599 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR3),
600 					AR5K_SISR3_QCBRORN);
601 		}
602 		if (data & AR5K_ISR_QCBRURN) {
603 			*interrupt_mask |= AR5K_INT_QCBRURN;
604 			ah->ah_txq_isr |= AR5K_REG_MS(
605 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR3),
606 					AR5K_SISR3_QCBRURN);
607 		}
608 		if (data & AR5K_ISR_QTRIG) {
609 			*interrupt_mask |= AR5K_INT_QTRIG;
610 			ah->ah_txq_isr |= AR5K_REG_MS(
611 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR4),
612 					AR5K_SISR4_QTRIG);
613 		}
614 
615 		if (data & AR5K_ISR_TXOK)
616 			ah->ah_txq_isr |= AR5K_REG_MS(
617 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR0),
618 					AR5K_SISR0_QCU_TXOK);
619 
620 		if (data & AR5K_ISR_TXDESC)
621 			ah->ah_txq_isr |= AR5K_REG_MS(
622 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR0),
623 					AR5K_SISR0_QCU_TXDESC);
624 
625 		if (data & AR5K_ISR_TXERR)
626 			ah->ah_txq_isr |= AR5K_REG_MS(
627 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR1),
628 					AR5K_SISR1_QCU_TXERR);
629 
630 		if (data & AR5K_ISR_TXEOL)
631 			ah->ah_txq_isr |= AR5K_REG_MS(
632 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR1),
633 					AR5K_SISR1_QCU_TXEOL);
634 
635 		if (data & AR5K_ISR_TXURN)
636 			ah->ah_txq_isr |= AR5K_REG_MS(
637 					ath5k_hw_reg_read(ah, AR5K_RAC_SISR2),
638 					AR5K_SISR2_QCU_TXURN);
639 	} else {
640 		if (unlikely(data & (AR5K_ISR_SSERR | AR5K_ISR_MCABT
641 				| AR5K_ISR_HIUERR | AR5K_ISR_DPERR)))
642 			*interrupt_mask |= AR5K_INT_FATAL;
643 
644 		/*
645 		 * XXX: BMISS interrupts may occur after association.
646 		 * I found this on 5210 code but it needs testing. If this is
647 		 * true we should disable them before assoc and re-enable them
648 		 * after a successful assoc + some jiffies.
649 			interrupt_mask &= ~AR5K_INT_BMISS;
650 		 */
651 	}
652 
653 	/*
654 	 * In case we didn't handle anything,
655 	 * print the register value.
656 	 */
657 	if (unlikely(*interrupt_mask == 0 && net_ratelimit()))
658 		ATH5K_PRINTF("ISR: 0x%08x IMR: 0x%08x\n", data, ah->ah_imr);
659 
660 	return 0;
661 }
662 
663 /**
664  * ath5k_hw_set_imr - Set interrupt mask
665  *
666  * @ah: The &struct ath5k_hw
667  * @new_mask: The new interrupt mask to be set
668  *
669  * Set the interrupt mask in hw to save interrupts. We do that by mapping
670  * ath5k_int bits to hw-specific bits to remove abstraction and writing
671  * Interrupt Mask Register.
672  */
673 enum ath5k_int ath5k_hw_set_imr(struct ath5k_hw *ah, enum ath5k_int new_mask)
674 {
675 	enum ath5k_int old_mask, int_mask;
676 
677 	old_mask = ah->ah_imr;
678 
679 	/*
680 	 * Disable card interrupts to prevent any race conditions
681 	 * (they will be re-enabled afterwards if AR5K_INT GLOBAL
682 	 * is set again on the new mask).
683 	 */
684 	if (old_mask & AR5K_INT_GLOBAL) {
685 		ath5k_hw_reg_write(ah, AR5K_IER_DISABLE, AR5K_IER);
686 		ath5k_hw_reg_read(ah, AR5K_IER);
687 	}
688 
689 	/*
690 	 * Add additional, chipset-dependent interrupt mask flags
691 	 * and write them to the IMR (interrupt mask register).
692 	 */
693 	int_mask = new_mask & AR5K_INT_COMMON;
694 
695 	if (ah->ah_version != AR5K_AR5210) {
696 		/* Preserve per queue TXURN interrupt mask */
697 		u32 simr2 = ath5k_hw_reg_read(ah, AR5K_SIMR2)
698 				& AR5K_SIMR2_QCU_TXURN;
699 
700 		if (new_mask & AR5K_INT_FATAL) {
701 			int_mask |= AR5K_IMR_HIUERR;
702 			simr2 |= (AR5K_SIMR2_MCABT | AR5K_SIMR2_SSERR
703 				| AR5K_SIMR2_DPERR);
704 		}
705 
706 		/*Beacon Not Ready*/
707 		if (new_mask & AR5K_INT_BNR)
708 			int_mask |= AR5K_INT_BNR;
709 
710 		if (new_mask & AR5K_INT_TIM)
711 			int_mask |= AR5K_IMR_TIM;
712 
713 		if (new_mask & AR5K_INT_TIM)
714 			simr2 |= AR5K_SISR2_TIM;
715 		if (new_mask & AR5K_INT_DTIM)
716 			simr2 |= AR5K_SISR2_DTIM;
717 		if (new_mask & AR5K_INT_DTIM_SYNC)
718 			simr2 |= AR5K_SISR2_DTIM_SYNC;
719 		if (new_mask & AR5K_INT_BCN_TIMEOUT)
720 			simr2 |= AR5K_SISR2_BCN_TIMEOUT;
721 		if (new_mask & AR5K_INT_CAB_TIMEOUT)
722 			simr2 |= AR5K_SISR2_CAB_TIMEOUT;
723 
724 		if (new_mask & AR5K_INT_RX_DOPPLER)
725 			int_mask |= AR5K_IMR_RXDOPPLER;
726 
727 		/* Note: Per queue interrupt masks
728 		 * are set via ath5k_hw_reset_tx_queue() (qcu.c) */
729 		ath5k_hw_reg_write(ah, int_mask, AR5K_PIMR);
730 		ath5k_hw_reg_write(ah, simr2, AR5K_SIMR2);
731 
732 	} else {
733 		if (new_mask & AR5K_INT_FATAL)
734 			int_mask |= (AR5K_IMR_SSERR | AR5K_IMR_MCABT
735 				| AR5K_IMR_HIUERR | AR5K_IMR_DPERR);
736 
737 		ath5k_hw_reg_write(ah, int_mask, AR5K_IMR);
738 	}
739 
740 	/* If RXNOFRM interrupt is masked disable it
741 	 * by setting AR5K_RXNOFRM to zero */
742 	if (!(new_mask & AR5K_INT_RXNOFRM))
743 		ath5k_hw_reg_write(ah, 0, AR5K_RXNOFRM);
744 
745 	/* Store new interrupt mask */
746 	ah->ah_imr = new_mask;
747 
748 	/* ..re-enable interrupts if AR5K_INT_GLOBAL is set */
749 	if (new_mask & AR5K_INT_GLOBAL) {
750 		ath5k_hw_reg_write(ah, AR5K_IER_ENABLE, AR5K_IER);
751 		ath5k_hw_reg_read(ah, AR5K_IER);
752 	}
753 
754 	return old_mask;
755 }
756 
757 
758 /********************\
759  Init/Stop functions
760 \********************/
761 
762 /**
763  * ath5k_hw_dma_init - Initialize DMA unit
764  *
765  * @ah: The &struct ath5k_hw
766  *
767  * Set DMA size and pre-enable interrupts
768  * (driver handles tx/rx buffer setup and
769  * dma start/stop)
770  *
771  * XXX: Save/restore RXDP/TXDP registers ?
772  */
773 void ath5k_hw_dma_init(struct ath5k_hw *ah)
774 {
775 	/*
776 	 * Set Rx/Tx DMA Configuration
777 	 *
778 	 * Set standard DMA size (128). Note that
779 	 * a DMA size of 512 causes rx overruns and tx errors
780 	 * on pci-e cards (tested on 5424 but since rx overruns
781 	 * also occur on 5416/5418 with madwifi we set 128
782 	 * for all PCI-E cards to be safe).
783 	 *
784 	 * XXX: need to check 5210 for this
785 	 * TODO: Check out tx trigger level, it's always 64 on dumps but I
786 	 * guess we can tweak it and see how it goes ;-)
787 	 */
788 	if (ah->ah_version != AR5K_AR5210) {
789 		AR5K_REG_WRITE_BITS(ah, AR5K_TXCFG,
790 			AR5K_TXCFG_SDMAMR, AR5K_DMASIZE_128B);
791 		AR5K_REG_WRITE_BITS(ah, AR5K_RXCFG,
792 			AR5K_RXCFG_SDMAMW, AR5K_DMASIZE_128B);
793 	}
794 
795 	/* Pre-enable interrupts on 5211/5212*/
796 	if (ah->ah_version != AR5K_AR5210)
797 		ath5k_hw_set_imr(ah, ah->ah_imr);
798 
799 }
800 
801 /**
802  * ath5k_hw_dma_stop - stop DMA unit
803  *
804  * @ah: The &struct ath5k_hw
805  *
806  * Stop tx/rx DMA and interrupts. Returns
807  * -EBUSY if tx or rx dma failed to stop.
808  *
809  * XXX: Sometimes DMA unit hangs and we have
810  * stuck frames on tx queues, only a reset
811  * can fix that.
812  */
813 int ath5k_hw_dma_stop(struct ath5k_hw *ah)
814 {
815 	int i, qmax, err;
816 	err = 0;
817 
818 	/* Disable interrupts */
819 	ath5k_hw_set_imr(ah, 0);
820 
821 	/* Stop rx dma */
822 	err = ath5k_hw_stop_rx_dma(ah);
823 	if (err)
824 		return err;
825 
826 	/* Clear any pending interrupts
827 	 * and disable tx dma */
828 	if (ah->ah_version != AR5K_AR5210) {
829 		ath5k_hw_reg_write(ah, 0xffffffff, AR5K_PISR);
830 		qmax = AR5K_NUM_TX_QUEUES;
831 	} else {
832 		/* PISR/SISR Not available on 5210 */
833 		ath5k_hw_reg_read(ah, AR5K_ISR);
834 		qmax = AR5K_NUM_TX_QUEUES_NOQCU;
835 	}
836 
837 	for (i = 0; i < qmax; i++) {
838 		err = ath5k_hw_stop_tx_dma(ah, i);
839 		/* -EINVAL -> queue inactive */
840 		if (err && err != -EINVAL)
841 			return err;
842 	}
843 
844 	return 0;
845 }
846