xref: /openbmc/linux/drivers/usb/musb/musb_cppi41.c (revision 711aab1d)
1 #include <linux/device.h>
2 #include <linux/dma-mapping.h>
3 #include <linux/dmaengine.h>
4 #include <linux/sizes.h>
5 #include <linux/platform_device.h>
6 #include <linux/of.h>
7 
8 #include "cppi_dma.h"
9 #include "musb_core.h"
10 #include "musb_trace.h"
11 
12 #define RNDIS_REG(x) (0x80 + ((x - 1) * 4))
13 
14 #define EP_MODE_AUTOREQ_NONE		0
15 #define EP_MODE_AUTOREQ_ALL_NEOP	1
16 #define EP_MODE_AUTOREQ_ALWAYS		3
17 
18 #define EP_MODE_DMA_TRANSPARENT		0
19 #define EP_MODE_DMA_RNDIS		1
20 #define EP_MODE_DMA_GEN_RNDIS		3
21 
22 #define USB_CTRL_TX_MODE	0x70
23 #define USB_CTRL_RX_MODE	0x74
24 #define USB_CTRL_AUTOREQ	0xd0
25 #define USB_TDOWN		0xd8
26 
27 #define MUSB_DMA_NUM_CHANNELS 15
28 
29 struct cppi41_dma_controller {
30 	struct dma_controller controller;
31 	struct cppi41_dma_channel rx_channel[MUSB_DMA_NUM_CHANNELS];
32 	struct cppi41_dma_channel tx_channel[MUSB_DMA_NUM_CHANNELS];
33 	struct hrtimer early_tx;
34 	struct list_head early_tx_list;
35 	u32 rx_mode;
36 	u32 tx_mode;
37 	u32 auto_req;
38 };
39 
40 static void save_rx_toggle(struct cppi41_dma_channel *cppi41_channel)
41 {
42 	u16 csr;
43 	u8 toggle;
44 
45 	if (cppi41_channel->is_tx)
46 		return;
47 	if (!is_host_active(cppi41_channel->controller->controller.musb))
48 		return;
49 
50 	csr = musb_readw(cppi41_channel->hw_ep->regs, MUSB_RXCSR);
51 	toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0;
52 
53 	cppi41_channel->usb_toggle = toggle;
54 }
55 
56 static void update_rx_toggle(struct cppi41_dma_channel *cppi41_channel)
57 {
58 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
59 	struct musb *musb = hw_ep->musb;
60 	u16 csr;
61 	u8 toggle;
62 
63 	if (cppi41_channel->is_tx)
64 		return;
65 	if (!is_host_active(musb))
66 		return;
67 
68 	musb_ep_select(musb->mregs, hw_ep->epnum);
69 	csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
70 	toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0;
71 
72 	/*
73 	 * AM335x Advisory 1.0.13: Due to internal synchronisation error the
74 	 * data toggle may reset from DATA1 to DATA0 during receiving data from
75 	 * more than one endpoint.
76 	 */
77 	if (!toggle && toggle == cppi41_channel->usb_toggle) {
78 		csr |= MUSB_RXCSR_H_DATATOGGLE | MUSB_RXCSR_H_WR_DATATOGGLE;
79 		musb_writew(cppi41_channel->hw_ep->regs, MUSB_RXCSR, csr);
80 		musb_dbg(musb, "Restoring DATA1 toggle.");
81 	}
82 
83 	cppi41_channel->usb_toggle = toggle;
84 }
85 
86 static bool musb_is_tx_fifo_empty(struct musb_hw_ep *hw_ep)
87 {
88 	u8		epnum = hw_ep->epnum;
89 	struct musb	*musb = hw_ep->musb;
90 	void __iomem	*epio = musb->endpoints[epnum].regs;
91 	u16		csr;
92 
93 	musb_ep_select(musb->mregs, hw_ep->epnum);
94 	csr = musb_readw(epio, MUSB_TXCSR);
95 	if (csr & MUSB_TXCSR_TXPKTRDY)
96 		return false;
97 	return true;
98 }
99 
100 static void cppi41_dma_callback(void *private_data,
101 				const struct dmaengine_result *result);
102 
103 static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
104 {
105 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
106 	struct musb *musb = hw_ep->musb;
107 	void __iomem *epio = hw_ep->regs;
108 	u16 csr;
109 
110 	if (!cppi41_channel->prog_len ||
111 	    (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)) {
112 
113 		/* done, complete */
114 		cppi41_channel->channel.actual_len =
115 			cppi41_channel->transferred;
116 		cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
117 		cppi41_channel->channel.rx_packet_done = true;
118 
119 		/*
120 		 * transmit ZLP using PIO mode for transfers which size is
121 		 * multiple of EP packet size.
122 		 */
123 		if (cppi41_channel->tx_zlp && (cppi41_channel->transferred %
124 					cppi41_channel->packet_sz) == 0) {
125 			musb_ep_select(musb->mregs, hw_ep->epnum);
126 			csr = MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY;
127 			musb_writew(epio, MUSB_TXCSR, csr);
128 		}
129 
130 		trace_musb_cppi41_done(cppi41_channel);
131 		musb_dma_completion(musb, hw_ep->epnum, cppi41_channel->is_tx);
132 	} else {
133 		/* next iteration, reload */
134 		struct dma_chan *dc = cppi41_channel->dc;
135 		struct dma_async_tx_descriptor *dma_desc;
136 		enum dma_transfer_direction direction;
137 		u32 remain_bytes;
138 
139 		cppi41_channel->buf_addr += cppi41_channel->packet_sz;
140 
141 		remain_bytes = cppi41_channel->total_len;
142 		remain_bytes -= cppi41_channel->transferred;
143 		remain_bytes = min(remain_bytes, cppi41_channel->packet_sz);
144 		cppi41_channel->prog_len = remain_bytes;
145 
146 		direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV
147 			: DMA_DEV_TO_MEM;
148 		dma_desc = dmaengine_prep_slave_single(dc,
149 				cppi41_channel->buf_addr,
150 				remain_bytes,
151 				direction,
152 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
153 		if (WARN_ON(!dma_desc))
154 			return;
155 
156 		dma_desc->callback_result = cppi41_dma_callback;
157 		dma_desc->callback_param = &cppi41_channel->channel;
158 		cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
159 		trace_musb_cppi41_cont(cppi41_channel);
160 		dma_async_issue_pending(dc);
161 
162 		if (!cppi41_channel->is_tx) {
163 			musb_ep_select(musb->mregs, hw_ep->epnum);
164 			csr = musb_readw(epio, MUSB_RXCSR);
165 			csr |= MUSB_RXCSR_H_REQPKT;
166 			musb_writew(epio, MUSB_RXCSR, csr);
167 		}
168 	}
169 }
170 
171 static enum hrtimer_restart cppi41_recheck_tx_req(struct hrtimer *timer)
172 {
173 	struct cppi41_dma_controller *controller;
174 	struct cppi41_dma_channel *cppi41_channel, *n;
175 	struct musb *musb;
176 	unsigned long flags;
177 	enum hrtimer_restart ret = HRTIMER_NORESTART;
178 
179 	controller = container_of(timer, struct cppi41_dma_controller,
180 			early_tx);
181 	musb = controller->controller.musb;
182 
183 	spin_lock_irqsave(&musb->lock, flags);
184 	list_for_each_entry_safe(cppi41_channel, n, &controller->early_tx_list,
185 			tx_check) {
186 		bool empty;
187 		struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
188 
189 		empty = musb_is_tx_fifo_empty(hw_ep);
190 		if (empty) {
191 			list_del_init(&cppi41_channel->tx_check);
192 			cppi41_trans_done(cppi41_channel);
193 		}
194 	}
195 
196 	if (!list_empty(&controller->early_tx_list) &&
197 	    !hrtimer_is_queued(&controller->early_tx)) {
198 		ret = HRTIMER_RESTART;
199 		hrtimer_forward_now(&controller->early_tx, 20 * NSEC_PER_USEC);
200 	}
201 
202 	spin_unlock_irqrestore(&musb->lock, flags);
203 	return ret;
204 }
205 
206 static void cppi41_dma_callback(void *private_data,
207 				const struct dmaengine_result *result)
208 {
209 	struct dma_channel *channel = private_data;
210 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
211 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
212 	struct cppi41_dma_controller *controller;
213 	struct musb *musb = hw_ep->musb;
214 	unsigned long flags;
215 	struct dma_tx_state txstate;
216 	u32 transferred;
217 	int is_hs = 0;
218 	bool empty;
219 
220 	controller = cppi41_channel->controller;
221 	if (controller->controller.dma_callback)
222 		controller->controller.dma_callback(&controller->controller);
223 
224 	if (result->result == DMA_TRANS_ABORTED)
225 		return;
226 
227 	spin_lock_irqsave(&musb->lock, flags);
228 
229 	dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
230 			&txstate);
231 	transferred = cppi41_channel->prog_len - txstate.residue;
232 	cppi41_channel->transferred += transferred;
233 
234 	trace_musb_cppi41_gb(cppi41_channel);
235 	update_rx_toggle(cppi41_channel);
236 
237 	if (cppi41_channel->transferred == cppi41_channel->total_len ||
238 			transferred < cppi41_channel->packet_sz)
239 		cppi41_channel->prog_len = 0;
240 
241 	if (cppi41_channel->is_tx) {
242 		u8 type;
243 
244 		if (is_host_active(musb))
245 			type = hw_ep->out_qh->type;
246 		else
247 			type = hw_ep->ep_in.type;
248 
249 		if (type == USB_ENDPOINT_XFER_ISOC)
250 			/*
251 			 * Don't use the early-TX-interrupt workaround below
252 			 * for Isoch transfter. Since Isoch are periodic
253 			 * transfer, by the time the next transfer is
254 			 * scheduled, the current one should be done already.
255 			 *
256 			 * This avoids audio playback underrun issue.
257 			 */
258 			empty = true;
259 		else
260 			empty = musb_is_tx_fifo_empty(hw_ep);
261 	}
262 
263 	if (!cppi41_channel->is_tx || empty) {
264 		cppi41_trans_done(cppi41_channel);
265 		goto out;
266 	}
267 
268 	/*
269 	 * On AM335x it has been observed that the TX interrupt fires
270 	 * too early that means the TXFIFO is not yet empty but the DMA
271 	 * engine says that it is done with the transfer. We don't
272 	 * receive a FIFO empty interrupt so the only thing we can do is
273 	 * to poll for the bit. On HS it usually takes 2us, on FS around
274 	 * 110us - 150us depending on the transfer size.
275 	 * We spin on HS (no longer than than 25us and setup a timer on
276 	 * FS to check for the bit and complete the transfer.
277 	 */
278 	if (is_host_active(musb)) {
279 		if (musb->port1_status & USB_PORT_STAT_HIGH_SPEED)
280 			is_hs = 1;
281 	} else {
282 		if (musb->g.speed == USB_SPEED_HIGH)
283 			is_hs = 1;
284 	}
285 	if (is_hs) {
286 		unsigned wait = 25;
287 
288 		do {
289 			empty = musb_is_tx_fifo_empty(hw_ep);
290 			if (empty) {
291 				cppi41_trans_done(cppi41_channel);
292 				goto out;
293 			}
294 			wait--;
295 			if (!wait)
296 				break;
297 			cpu_relax();
298 		} while (1);
299 	}
300 	list_add_tail(&cppi41_channel->tx_check,
301 			&controller->early_tx_list);
302 	if (!hrtimer_is_queued(&controller->early_tx)) {
303 		unsigned long usecs = cppi41_channel->total_len / 10;
304 
305 		hrtimer_start_range_ns(&controller->early_tx,
306 				       usecs * NSEC_PER_USEC,
307 				       20 * NSEC_PER_USEC,
308 				       HRTIMER_MODE_REL);
309 	}
310 
311 out:
312 	spin_unlock_irqrestore(&musb->lock, flags);
313 }
314 
315 static u32 update_ep_mode(unsigned ep, unsigned mode, u32 old)
316 {
317 	unsigned shift;
318 
319 	shift = (ep - 1) * 2;
320 	old &= ~(3 << shift);
321 	old |= mode << shift;
322 	return old;
323 }
324 
325 static void cppi41_set_dma_mode(struct cppi41_dma_channel *cppi41_channel,
326 		unsigned mode)
327 {
328 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
329 	struct musb *musb = controller->controller.musb;
330 	u32 port;
331 	u32 new_mode;
332 	u32 old_mode;
333 
334 	if (cppi41_channel->is_tx)
335 		old_mode = controller->tx_mode;
336 	else
337 		old_mode = controller->rx_mode;
338 	port = cppi41_channel->port_num;
339 	new_mode = update_ep_mode(port, mode, old_mode);
340 
341 	if (new_mode == old_mode)
342 		return;
343 	if (cppi41_channel->is_tx) {
344 		controller->tx_mode = new_mode;
345 		musb_writel(musb->ctrl_base, USB_CTRL_TX_MODE, new_mode);
346 	} else {
347 		controller->rx_mode = new_mode;
348 		musb_writel(musb->ctrl_base, USB_CTRL_RX_MODE, new_mode);
349 	}
350 }
351 
352 static void cppi41_set_autoreq_mode(struct cppi41_dma_channel *cppi41_channel,
353 		unsigned mode)
354 {
355 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
356 	u32 port;
357 	u32 new_mode;
358 	u32 old_mode;
359 
360 	old_mode = controller->auto_req;
361 	port = cppi41_channel->port_num;
362 	new_mode = update_ep_mode(port, mode, old_mode);
363 
364 	if (new_mode == old_mode)
365 		return;
366 	controller->auto_req = new_mode;
367 	musb_writel(controller->controller.musb->ctrl_base, USB_CTRL_AUTOREQ,
368 		    new_mode);
369 }
370 
371 static bool cppi41_configure_channel(struct dma_channel *channel,
372 				u16 packet_sz, u8 mode,
373 				dma_addr_t dma_addr, u32 len)
374 {
375 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
376 	struct dma_chan *dc = cppi41_channel->dc;
377 	struct dma_async_tx_descriptor *dma_desc;
378 	enum dma_transfer_direction direction;
379 	struct musb *musb = cppi41_channel->controller->controller.musb;
380 	unsigned use_gen_rndis = 0;
381 
382 	cppi41_channel->buf_addr = dma_addr;
383 	cppi41_channel->total_len = len;
384 	cppi41_channel->transferred = 0;
385 	cppi41_channel->packet_sz = packet_sz;
386 	cppi41_channel->tx_zlp = (cppi41_channel->is_tx && mode) ? 1 : 0;
387 
388 	/*
389 	 * Due to AM335x' Advisory 1.0.13 we are not allowed to transfer more
390 	 * than max packet size at a time.
391 	 */
392 	if (cppi41_channel->is_tx)
393 		use_gen_rndis = 1;
394 
395 	if (use_gen_rndis) {
396 		/* RNDIS mode */
397 		if (len > packet_sz) {
398 			musb_writel(musb->ctrl_base,
399 				RNDIS_REG(cppi41_channel->port_num), len);
400 			/* gen rndis */
401 			cppi41_set_dma_mode(cppi41_channel,
402 					EP_MODE_DMA_GEN_RNDIS);
403 
404 			/* auto req */
405 			cppi41_set_autoreq_mode(cppi41_channel,
406 					EP_MODE_AUTOREQ_ALL_NEOP);
407 		} else {
408 			musb_writel(musb->ctrl_base,
409 					RNDIS_REG(cppi41_channel->port_num), 0);
410 			cppi41_set_dma_mode(cppi41_channel,
411 					EP_MODE_DMA_TRANSPARENT);
412 			cppi41_set_autoreq_mode(cppi41_channel,
413 					EP_MODE_AUTOREQ_NONE);
414 		}
415 	} else {
416 		/* fallback mode */
417 		cppi41_set_dma_mode(cppi41_channel, EP_MODE_DMA_TRANSPARENT);
418 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);
419 		len = min_t(u32, packet_sz, len);
420 	}
421 	cppi41_channel->prog_len = len;
422 	direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
423 	dma_desc = dmaengine_prep_slave_single(dc, dma_addr, len, direction,
424 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
425 	if (!dma_desc)
426 		return false;
427 
428 	dma_desc->callback_result = cppi41_dma_callback;
429 	dma_desc->callback_param = channel;
430 	cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
431 	cppi41_channel->channel.rx_packet_done = false;
432 
433 	trace_musb_cppi41_config(cppi41_channel);
434 
435 	save_rx_toggle(cppi41_channel);
436 	dma_async_issue_pending(dc);
437 	return true;
438 }
439 
440 static struct dma_channel *cppi41_dma_channel_allocate(struct dma_controller *c,
441 				struct musb_hw_ep *hw_ep, u8 is_tx)
442 {
443 	struct cppi41_dma_controller *controller = container_of(c,
444 			struct cppi41_dma_controller, controller);
445 	struct cppi41_dma_channel *cppi41_channel = NULL;
446 	u8 ch_num = hw_ep->epnum - 1;
447 
448 	if (ch_num >= MUSB_DMA_NUM_CHANNELS)
449 		return NULL;
450 
451 	if (is_tx)
452 		cppi41_channel = &controller->tx_channel[ch_num];
453 	else
454 		cppi41_channel = &controller->rx_channel[ch_num];
455 
456 	if (!cppi41_channel->dc)
457 		return NULL;
458 
459 	if (cppi41_channel->is_allocated)
460 		return NULL;
461 
462 	cppi41_channel->hw_ep = hw_ep;
463 	cppi41_channel->is_allocated = 1;
464 
465 	trace_musb_cppi41_alloc(cppi41_channel);
466 	return &cppi41_channel->channel;
467 }
468 
469 static void cppi41_dma_channel_release(struct dma_channel *channel)
470 {
471 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
472 
473 	trace_musb_cppi41_free(cppi41_channel);
474 	if (cppi41_channel->is_allocated) {
475 		cppi41_channel->is_allocated = 0;
476 		channel->status = MUSB_DMA_STATUS_FREE;
477 		channel->actual_len = 0;
478 	}
479 }
480 
481 static int cppi41_dma_channel_program(struct dma_channel *channel,
482 				u16 packet_sz, u8 mode,
483 				dma_addr_t dma_addr, u32 len)
484 {
485 	int ret;
486 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
487 	int hb_mult = 0;
488 
489 	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
490 		channel->status == MUSB_DMA_STATUS_BUSY);
491 
492 	if (is_host_active(cppi41_channel->controller->controller.musb)) {
493 		if (cppi41_channel->is_tx)
494 			hb_mult = cppi41_channel->hw_ep->out_qh->hb_mult;
495 		else
496 			hb_mult = cppi41_channel->hw_ep->in_qh->hb_mult;
497 	}
498 
499 	channel->status = MUSB_DMA_STATUS_BUSY;
500 	channel->actual_len = 0;
501 
502 	if (hb_mult)
503 		packet_sz = hb_mult * (packet_sz & 0x7FF);
504 
505 	ret = cppi41_configure_channel(channel, packet_sz, mode, dma_addr, len);
506 	if (!ret)
507 		channel->status = MUSB_DMA_STATUS_FREE;
508 
509 	return ret;
510 }
511 
512 static int cppi41_is_compatible(struct dma_channel *channel, u16 maxpacket,
513 		void *buf, u32 length)
514 {
515 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
516 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
517 	struct musb *musb = controller->controller.musb;
518 
519 	if (is_host_active(musb)) {
520 		WARN_ON(1);
521 		return 1;
522 	}
523 	if (cppi41_channel->hw_ep->ep_in.type != USB_ENDPOINT_XFER_BULK)
524 		return 0;
525 	if (cppi41_channel->is_tx)
526 		return 1;
527 	/* AM335x Advisory 1.0.13. No workaround for device RX mode */
528 	return 0;
529 }
530 
531 static int cppi41_dma_channel_abort(struct dma_channel *channel)
532 {
533 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
534 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
535 	struct musb *musb = controller->controller.musb;
536 	void __iomem *epio = cppi41_channel->hw_ep->regs;
537 	int tdbit;
538 	int ret;
539 	unsigned is_tx;
540 	u16 csr;
541 
542 	is_tx = cppi41_channel->is_tx;
543 	trace_musb_cppi41_abort(cppi41_channel);
544 
545 	if (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)
546 		return 0;
547 
548 	list_del_init(&cppi41_channel->tx_check);
549 	if (is_tx) {
550 		csr = musb_readw(epio, MUSB_TXCSR);
551 		csr &= ~MUSB_TXCSR_DMAENAB;
552 		musb_writew(epio, MUSB_TXCSR, csr);
553 	} else {
554 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);
555 
556 		/* delay to drain to cppi dma pipeline for isoch */
557 		udelay(250);
558 
559 		csr = musb_readw(epio, MUSB_RXCSR);
560 		csr &= ~(MUSB_RXCSR_H_REQPKT | MUSB_RXCSR_DMAENAB);
561 		musb_writew(epio, MUSB_RXCSR, csr);
562 
563 		/* wait to drain cppi dma pipe line */
564 		udelay(50);
565 
566 		csr = musb_readw(epio, MUSB_RXCSR);
567 		if (csr & MUSB_RXCSR_RXPKTRDY) {
568 			csr |= MUSB_RXCSR_FLUSHFIFO;
569 			musb_writew(epio, MUSB_RXCSR, csr);
570 			musb_writew(epio, MUSB_RXCSR, csr);
571 		}
572 	}
573 
574 	/* DA8xx Advisory 2.3.27: wait 250 ms before to start the teardown */
575 	if (musb->io.quirks & MUSB_DA8XX)
576 		mdelay(250);
577 
578 	tdbit = 1 << cppi41_channel->port_num;
579 	if (is_tx)
580 		tdbit <<= 16;
581 
582 	do {
583 		if (is_tx)
584 			musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
585 		ret = dmaengine_terminate_all(cppi41_channel->dc);
586 	} while (ret == -EAGAIN);
587 
588 	if (is_tx) {
589 		musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
590 
591 		csr = musb_readw(epio, MUSB_TXCSR);
592 		if (csr & MUSB_TXCSR_TXPKTRDY) {
593 			csr |= MUSB_TXCSR_FLUSHFIFO;
594 			musb_writew(epio, MUSB_TXCSR, csr);
595 		}
596 	}
597 
598 	cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
599 	return 0;
600 }
601 
602 static void cppi41_release_all_dma_chans(struct cppi41_dma_controller *ctrl)
603 {
604 	struct dma_chan *dc;
605 	int i;
606 
607 	for (i = 0; i < MUSB_DMA_NUM_CHANNELS; i++) {
608 		dc = ctrl->tx_channel[i].dc;
609 		if (dc)
610 			dma_release_channel(dc);
611 		dc = ctrl->rx_channel[i].dc;
612 		if (dc)
613 			dma_release_channel(dc);
614 	}
615 }
616 
617 static void cppi41_dma_controller_stop(struct cppi41_dma_controller *controller)
618 {
619 	cppi41_release_all_dma_chans(controller);
620 }
621 
622 static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
623 {
624 	struct musb *musb = controller->controller.musb;
625 	struct device *dev = musb->controller;
626 	struct device_node *np = dev->parent->of_node;
627 	struct cppi41_dma_channel *cppi41_channel;
628 	int count;
629 	int i;
630 	int ret;
631 
632 	count = of_property_count_strings(np, "dma-names");
633 	if (count < 0)
634 		return count;
635 
636 	for (i = 0; i < count; i++) {
637 		struct dma_chan *dc;
638 		struct dma_channel *musb_dma;
639 		const char *str;
640 		unsigned is_tx;
641 		unsigned int port;
642 
643 		ret = of_property_read_string_index(np, "dma-names", i, &str);
644 		if (ret)
645 			goto err;
646 		if (strstarts(str, "tx"))
647 			is_tx = 1;
648 		else if (strstarts(str, "rx"))
649 			is_tx = 0;
650 		else {
651 			dev_err(dev, "Wrong dmatype %s\n", str);
652 			goto err;
653 		}
654 		ret = kstrtouint(str + 2, 0, &port);
655 		if (ret)
656 			goto err;
657 
658 		ret = -EINVAL;
659 		if (port > MUSB_DMA_NUM_CHANNELS || !port)
660 			goto err;
661 		if (is_tx)
662 			cppi41_channel = &controller->tx_channel[port - 1];
663 		else
664 			cppi41_channel = &controller->rx_channel[port - 1];
665 
666 		cppi41_channel->controller = controller;
667 		cppi41_channel->port_num = port;
668 		cppi41_channel->is_tx = is_tx;
669 		INIT_LIST_HEAD(&cppi41_channel->tx_check);
670 
671 		musb_dma = &cppi41_channel->channel;
672 		musb_dma->private_data = cppi41_channel;
673 		musb_dma->status = MUSB_DMA_STATUS_FREE;
674 		musb_dma->max_len = SZ_4M;
675 
676 		dc = dma_request_chan(dev->parent, str);
677 		if (IS_ERR(dc)) {
678 			ret = PTR_ERR(dc);
679 			if (ret != -EPROBE_DEFER)
680 				dev_err(dev, "Failed to request %s: %d.\n",
681 					str, ret);
682 			goto err;
683 		}
684 
685 		cppi41_channel->dc = dc;
686 	}
687 	return 0;
688 err:
689 	cppi41_release_all_dma_chans(controller);
690 	return ret;
691 }
692 
693 void cppi41_dma_controller_destroy(struct dma_controller *c)
694 {
695 	struct cppi41_dma_controller *controller = container_of(c,
696 			struct cppi41_dma_controller, controller);
697 
698 	hrtimer_cancel(&controller->early_tx);
699 	cppi41_dma_controller_stop(controller);
700 	kfree(controller);
701 }
702 EXPORT_SYMBOL_GPL(cppi41_dma_controller_destroy);
703 
704 struct dma_controller *
705 cppi41_dma_controller_create(struct musb *musb, void __iomem *base)
706 {
707 	struct cppi41_dma_controller *controller;
708 	int ret = 0;
709 
710 	if (!musb->controller->parent->of_node) {
711 		dev_err(musb->controller, "Need DT for the DMA engine.\n");
712 		return NULL;
713 	}
714 
715 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
716 	if (!controller)
717 		goto kzalloc_fail;
718 
719 	hrtimer_init(&controller->early_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
720 	controller->early_tx.function = cppi41_recheck_tx_req;
721 	INIT_LIST_HEAD(&controller->early_tx_list);
722 
723 	controller->controller.channel_alloc = cppi41_dma_channel_allocate;
724 	controller->controller.channel_release = cppi41_dma_channel_release;
725 	controller->controller.channel_program = cppi41_dma_channel_program;
726 	controller->controller.channel_abort = cppi41_dma_channel_abort;
727 	controller->controller.is_compatible = cppi41_is_compatible;
728 	controller->controller.musb = musb;
729 
730 	ret = cppi41_dma_controller_start(controller);
731 	if (ret)
732 		goto plat_get_fail;
733 	return &controller->controller;
734 
735 plat_get_fail:
736 	kfree(controller);
737 kzalloc_fail:
738 	if (ret == -EPROBE_DEFER)
739 		return ERR_PTR(ret);
740 	return NULL;
741 }
742 EXPORT_SYMBOL_GPL(cppi41_dma_controller_create);
743