xref: /linux/drivers/usb/musb/musb_cppi41.c (revision b246a9d2671f4f6cfab3f98199568e0b3028f6e5)
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 musb *musb;
34 	struct hrtimer early_tx;
35 	struct list_head early_tx_list;
36 	u32 rx_mode;
37 	u32 tx_mode;
38 	u32 auto_req;
39 };
40 
41 static void save_rx_toggle(struct cppi41_dma_channel *cppi41_channel)
42 {
43 	u16 csr;
44 	u8 toggle;
45 
46 	if (cppi41_channel->is_tx)
47 		return;
48 	if (!is_host_active(cppi41_channel->controller->musb))
49 		return;
50 
51 	csr = musb_readw(cppi41_channel->hw_ep->regs, MUSB_RXCSR);
52 	toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0;
53 
54 	cppi41_channel->usb_toggle = toggle;
55 }
56 
57 static void update_rx_toggle(struct cppi41_dma_channel *cppi41_channel)
58 {
59 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
60 	struct musb *musb = hw_ep->musb;
61 	u16 csr;
62 	u8 toggle;
63 
64 	if (cppi41_channel->is_tx)
65 		return;
66 	if (!is_host_active(musb))
67 		return;
68 
69 	musb_ep_select(musb->mregs, hw_ep->epnum);
70 	csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
71 	toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0;
72 
73 	/*
74 	 * AM335x Advisory 1.0.13: Due to internal synchronisation error the
75 	 * data toggle may reset from DATA1 to DATA0 during receiving data from
76 	 * more than one endpoint.
77 	 */
78 	if (!toggle && toggle == cppi41_channel->usb_toggle) {
79 		csr |= MUSB_RXCSR_H_DATATOGGLE | MUSB_RXCSR_H_WR_DATATOGGLE;
80 		musb_writew(cppi41_channel->hw_ep->regs, MUSB_RXCSR, csr);
81 		musb_dbg(cppi41_channel->controller->musb,
82 				"Restoring DATA1 toggle.");
83 	}
84 
85 	cppi41_channel->usb_toggle = toggle;
86 }
87 
88 static bool musb_is_tx_fifo_empty(struct musb_hw_ep *hw_ep)
89 {
90 	u8		epnum = hw_ep->epnum;
91 	struct musb	*musb = hw_ep->musb;
92 	void __iomem	*epio = musb->endpoints[epnum].regs;
93 	u16		csr;
94 
95 	musb_ep_select(musb->mregs, hw_ep->epnum);
96 	csr = musb_readw(epio, MUSB_TXCSR);
97 	if (csr & MUSB_TXCSR_TXPKTRDY)
98 		return false;
99 	return true;
100 }
101 
102 static void cppi41_dma_callback(void *private_data);
103 
104 static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
105 {
106 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
107 	struct musb *musb = hw_ep->musb;
108 	void __iomem *epio = hw_ep->regs;
109 	u16 csr;
110 
111 	if (!cppi41_channel->prog_len ||
112 	    (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)) {
113 
114 		/* done, complete */
115 		cppi41_channel->channel.actual_len =
116 			cppi41_channel->transferred;
117 		cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
118 		cppi41_channel->channel.rx_packet_done = true;
119 
120 		/*
121 		 * transmit ZLP using PIO mode for transfers which size is
122 		 * multiple of EP packet size.
123 		 */
124 		if (cppi41_channel->tx_zlp && (cppi41_channel->transferred %
125 					cppi41_channel->packet_sz) == 0) {
126 			musb_ep_select(musb->mregs, hw_ep->epnum);
127 			csr = MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY;
128 			musb_writew(epio, MUSB_TXCSR, csr);
129 		}
130 
131 		trace_musb_cppi41_done(cppi41_channel);
132 		musb_dma_completion(musb, hw_ep->epnum, cppi41_channel->is_tx);
133 	} else {
134 		/* next iteration, reload */
135 		struct dma_chan *dc = cppi41_channel->dc;
136 		struct dma_async_tx_descriptor *dma_desc;
137 		enum dma_transfer_direction direction;
138 		u32 remain_bytes;
139 
140 		cppi41_channel->buf_addr += cppi41_channel->packet_sz;
141 
142 		remain_bytes = cppi41_channel->total_len;
143 		remain_bytes -= cppi41_channel->transferred;
144 		remain_bytes = min(remain_bytes, cppi41_channel->packet_sz);
145 		cppi41_channel->prog_len = remain_bytes;
146 
147 		direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV
148 			: DMA_DEV_TO_MEM;
149 		dma_desc = dmaengine_prep_slave_single(dc,
150 				cppi41_channel->buf_addr,
151 				remain_bytes,
152 				direction,
153 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
154 		if (WARN_ON(!dma_desc))
155 			return;
156 
157 		dma_desc->callback = cppi41_dma_callback;
158 		dma_desc->callback_param = &cppi41_channel->channel;
159 		cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
160 		trace_musb_cppi41_cont(cppi41_channel);
161 		dma_async_issue_pending(dc);
162 
163 		if (!cppi41_channel->is_tx) {
164 			musb_ep_select(musb->mregs, hw_ep->epnum);
165 			csr = musb_readw(epio, MUSB_RXCSR);
166 			csr |= MUSB_RXCSR_H_REQPKT;
167 			musb_writew(epio, MUSB_RXCSR, csr);
168 		}
169 	}
170 }
171 
172 static enum hrtimer_restart cppi41_recheck_tx_req(struct hrtimer *timer)
173 {
174 	struct cppi41_dma_controller *controller;
175 	struct cppi41_dma_channel *cppi41_channel, *n;
176 	struct musb *musb;
177 	unsigned long flags;
178 	enum hrtimer_restart ret = HRTIMER_NORESTART;
179 
180 	controller = container_of(timer, struct cppi41_dma_controller,
181 			early_tx);
182 	musb = controller->musb;
183 
184 	spin_lock_irqsave(&musb->lock, flags);
185 	list_for_each_entry_safe(cppi41_channel, n, &controller->early_tx_list,
186 			tx_check) {
187 		bool empty;
188 		struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
189 
190 		empty = musb_is_tx_fifo_empty(hw_ep);
191 		if (empty) {
192 			list_del_init(&cppi41_channel->tx_check);
193 			cppi41_trans_done(cppi41_channel);
194 		}
195 	}
196 
197 	if (!list_empty(&controller->early_tx_list) &&
198 	    !hrtimer_is_queued(&controller->early_tx)) {
199 		ret = HRTIMER_RESTART;
200 		hrtimer_forward_now(&controller->early_tx, 20 * NSEC_PER_USEC);
201 	}
202 
203 	spin_unlock_irqrestore(&musb->lock, flags);
204 	return ret;
205 }
206 
207 static void cppi41_dma_callback(void *private_data)
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 	spin_lock_irqsave(&musb->lock, flags);
221 
222 	dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
223 			&txstate);
224 	transferred = cppi41_channel->prog_len - txstate.residue;
225 	cppi41_channel->transferred += transferred;
226 
227 	trace_musb_cppi41_gb(cppi41_channel);
228 	update_rx_toggle(cppi41_channel);
229 
230 	if (cppi41_channel->transferred == cppi41_channel->total_len ||
231 			transferred < cppi41_channel->packet_sz)
232 		cppi41_channel->prog_len = 0;
233 
234 	if (cppi41_channel->is_tx)
235 		empty = musb_is_tx_fifo_empty(hw_ep);
236 
237 	if (!cppi41_channel->is_tx || empty) {
238 		cppi41_trans_done(cppi41_channel);
239 		goto out;
240 	}
241 
242 	/*
243 	 * On AM335x it has been observed that the TX interrupt fires
244 	 * too early that means the TXFIFO is not yet empty but the DMA
245 	 * engine says that it is done with the transfer. We don't
246 	 * receive a FIFO empty interrupt so the only thing we can do is
247 	 * to poll for the bit. On HS it usually takes 2us, on FS around
248 	 * 110us - 150us depending on the transfer size.
249 	 * We spin on HS (no longer than than 25us and setup a timer on
250 	 * FS to check for the bit and complete the transfer.
251 	 */
252 	controller = cppi41_channel->controller;
253 
254 	if (is_host_active(musb)) {
255 		if (musb->port1_status & USB_PORT_STAT_HIGH_SPEED)
256 			is_hs = 1;
257 	} else {
258 		if (musb->g.speed == USB_SPEED_HIGH)
259 			is_hs = 1;
260 	}
261 	if (is_hs) {
262 		unsigned wait = 25;
263 
264 		do {
265 			empty = musb_is_tx_fifo_empty(hw_ep);
266 			if (empty) {
267 				cppi41_trans_done(cppi41_channel);
268 				goto out;
269 			}
270 			wait--;
271 			if (!wait)
272 				break;
273 			cpu_relax();
274 		} while (1);
275 	}
276 	list_add_tail(&cppi41_channel->tx_check,
277 			&controller->early_tx_list);
278 	if (!hrtimer_is_queued(&controller->early_tx)) {
279 		unsigned long usecs = cppi41_channel->total_len / 10;
280 
281 		hrtimer_start_range_ns(&controller->early_tx,
282 				       usecs * NSEC_PER_USEC,
283 				       20 * NSEC_PER_USEC,
284 				       HRTIMER_MODE_REL);
285 	}
286 
287 out:
288 	spin_unlock_irqrestore(&musb->lock, flags);
289 }
290 
291 static u32 update_ep_mode(unsigned ep, unsigned mode, u32 old)
292 {
293 	unsigned shift;
294 
295 	shift = (ep - 1) * 2;
296 	old &= ~(3 << shift);
297 	old |= mode << shift;
298 	return old;
299 }
300 
301 static void cppi41_set_dma_mode(struct cppi41_dma_channel *cppi41_channel,
302 		unsigned mode)
303 {
304 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
305 	u32 port;
306 	u32 new_mode;
307 	u32 old_mode;
308 
309 	if (cppi41_channel->is_tx)
310 		old_mode = controller->tx_mode;
311 	else
312 		old_mode = controller->rx_mode;
313 	port = cppi41_channel->port_num;
314 	new_mode = update_ep_mode(port, mode, old_mode);
315 
316 	if (new_mode == old_mode)
317 		return;
318 	if (cppi41_channel->is_tx) {
319 		controller->tx_mode = new_mode;
320 		musb_writel(controller->musb->ctrl_base, USB_CTRL_TX_MODE,
321 				new_mode);
322 	} else {
323 		controller->rx_mode = new_mode;
324 		musb_writel(controller->musb->ctrl_base, USB_CTRL_RX_MODE,
325 				new_mode);
326 	}
327 }
328 
329 static void cppi41_set_autoreq_mode(struct cppi41_dma_channel *cppi41_channel,
330 		unsigned mode)
331 {
332 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
333 	u32 port;
334 	u32 new_mode;
335 	u32 old_mode;
336 
337 	old_mode = controller->auto_req;
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 	controller->auto_req = new_mode;
344 	musb_writel(controller->musb->ctrl_base, USB_CTRL_AUTOREQ, new_mode);
345 }
346 
347 static bool cppi41_configure_channel(struct dma_channel *channel,
348 				u16 packet_sz, u8 mode,
349 				dma_addr_t dma_addr, u32 len)
350 {
351 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
352 	struct dma_chan *dc = cppi41_channel->dc;
353 	struct dma_async_tx_descriptor *dma_desc;
354 	enum dma_transfer_direction direction;
355 	struct musb *musb = cppi41_channel->controller->musb;
356 	unsigned use_gen_rndis = 0;
357 
358 	cppi41_channel->buf_addr = dma_addr;
359 	cppi41_channel->total_len = len;
360 	cppi41_channel->transferred = 0;
361 	cppi41_channel->packet_sz = packet_sz;
362 	cppi41_channel->tx_zlp = (cppi41_channel->is_tx && mode) ? 1 : 0;
363 
364 	/*
365 	 * Due to AM335x' Advisory 1.0.13 we are not allowed to transfer more
366 	 * than max packet size at a time.
367 	 */
368 	if (cppi41_channel->is_tx)
369 		use_gen_rndis = 1;
370 
371 	if (use_gen_rndis) {
372 		/* RNDIS mode */
373 		if (len > packet_sz) {
374 			musb_writel(musb->ctrl_base,
375 				RNDIS_REG(cppi41_channel->port_num), len);
376 			/* gen rndis */
377 			cppi41_set_dma_mode(cppi41_channel,
378 					EP_MODE_DMA_GEN_RNDIS);
379 
380 			/* auto req */
381 			cppi41_set_autoreq_mode(cppi41_channel,
382 					EP_MODE_AUTOREQ_ALL_NEOP);
383 		} else {
384 			musb_writel(musb->ctrl_base,
385 					RNDIS_REG(cppi41_channel->port_num), 0);
386 			cppi41_set_dma_mode(cppi41_channel,
387 					EP_MODE_DMA_TRANSPARENT);
388 			cppi41_set_autoreq_mode(cppi41_channel,
389 					EP_MODE_AUTOREQ_NONE);
390 		}
391 	} else {
392 		/* fallback mode */
393 		cppi41_set_dma_mode(cppi41_channel, EP_MODE_DMA_TRANSPARENT);
394 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);
395 		len = min_t(u32, packet_sz, len);
396 	}
397 	cppi41_channel->prog_len = len;
398 	direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
399 	dma_desc = dmaengine_prep_slave_single(dc, dma_addr, len, direction,
400 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
401 	if (!dma_desc)
402 		return false;
403 
404 	dma_desc->callback = cppi41_dma_callback;
405 	dma_desc->callback_param = channel;
406 	cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
407 	cppi41_channel->channel.rx_packet_done = false;
408 
409 	trace_musb_cppi41_config(cppi41_channel);
410 
411 	save_rx_toggle(cppi41_channel);
412 	dma_async_issue_pending(dc);
413 	return true;
414 }
415 
416 static struct dma_channel *cppi41_dma_channel_allocate(struct dma_controller *c,
417 				struct musb_hw_ep *hw_ep, u8 is_tx)
418 {
419 	struct cppi41_dma_controller *controller = container_of(c,
420 			struct cppi41_dma_controller, controller);
421 	struct cppi41_dma_channel *cppi41_channel = NULL;
422 	u8 ch_num = hw_ep->epnum - 1;
423 
424 	if (ch_num >= MUSB_DMA_NUM_CHANNELS)
425 		return NULL;
426 
427 	if (is_tx)
428 		cppi41_channel = &controller->tx_channel[ch_num];
429 	else
430 		cppi41_channel = &controller->rx_channel[ch_num];
431 
432 	if (!cppi41_channel->dc)
433 		return NULL;
434 
435 	if (cppi41_channel->is_allocated)
436 		return NULL;
437 
438 	cppi41_channel->hw_ep = hw_ep;
439 	cppi41_channel->is_allocated = 1;
440 
441 	trace_musb_cppi41_alloc(cppi41_channel);
442 	return &cppi41_channel->channel;
443 }
444 
445 static void cppi41_dma_channel_release(struct dma_channel *channel)
446 {
447 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
448 
449 	trace_musb_cppi41_free(cppi41_channel);
450 	if (cppi41_channel->is_allocated) {
451 		cppi41_channel->is_allocated = 0;
452 		channel->status = MUSB_DMA_STATUS_FREE;
453 		channel->actual_len = 0;
454 	}
455 }
456 
457 static int cppi41_dma_channel_program(struct dma_channel *channel,
458 				u16 packet_sz, u8 mode,
459 				dma_addr_t dma_addr, u32 len)
460 {
461 	int ret;
462 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
463 	int hb_mult = 0;
464 
465 	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
466 		channel->status == MUSB_DMA_STATUS_BUSY);
467 
468 	if (is_host_active(cppi41_channel->controller->musb)) {
469 		if (cppi41_channel->is_tx)
470 			hb_mult = cppi41_channel->hw_ep->out_qh->hb_mult;
471 		else
472 			hb_mult = cppi41_channel->hw_ep->in_qh->hb_mult;
473 	}
474 
475 	channel->status = MUSB_DMA_STATUS_BUSY;
476 	channel->actual_len = 0;
477 
478 	if (hb_mult)
479 		packet_sz = hb_mult * (packet_sz & 0x7FF);
480 
481 	ret = cppi41_configure_channel(channel, packet_sz, mode, dma_addr, len);
482 	if (!ret)
483 		channel->status = MUSB_DMA_STATUS_FREE;
484 
485 	return ret;
486 }
487 
488 static int cppi41_is_compatible(struct dma_channel *channel, u16 maxpacket,
489 		void *buf, u32 length)
490 {
491 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
492 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
493 	struct musb *musb = controller->musb;
494 
495 	if (is_host_active(musb)) {
496 		WARN_ON(1);
497 		return 1;
498 	}
499 	if (cppi41_channel->hw_ep->ep_in.type != USB_ENDPOINT_XFER_BULK)
500 		return 0;
501 	if (cppi41_channel->is_tx)
502 		return 1;
503 	/* AM335x Advisory 1.0.13. No workaround for device RX mode */
504 	return 0;
505 }
506 
507 static int cppi41_dma_channel_abort(struct dma_channel *channel)
508 {
509 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
510 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
511 	struct musb *musb = controller->musb;
512 	void __iomem *epio = cppi41_channel->hw_ep->regs;
513 	int tdbit;
514 	int ret;
515 	unsigned is_tx;
516 	u16 csr;
517 
518 	is_tx = cppi41_channel->is_tx;
519 	trace_musb_cppi41_abort(cppi41_channel);
520 
521 	if (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)
522 		return 0;
523 
524 	list_del_init(&cppi41_channel->tx_check);
525 	if (is_tx) {
526 		csr = musb_readw(epio, MUSB_TXCSR);
527 		csr &= ~MUSB_TXCSR_DMAENAB;
528 		musb_writew(epio, MUSB_TXCSR, csr);
529 	} else {
530 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);
531 
532 		/* delay to drain to cppi dma pipeline for isoch */
533 		udelay(250);
534 
535 		csr = musb_readw(epio, MUSB_RXCSR);
536 		csr &= ~(MUSB_RXCSR_H_REQPKT | MUSB_RXCSR_DMAENAB);
537 		musb_writew(epio, MUSB_RXCSR, csr);
538 
539 		/* wait to drain cppi dma pipe line */
540 		udelay(50);
541 
542 		csr = musb_readw(epio, MUSB_RXCSR);
543 		if (csr & MUSB_RXCSR_RXPKTRDY) {
544 			csr |= MUSB_RXCSR_FLUSHFIFO;
545 			musb_writew(epio, MUSB_RXCSR, csr);
546 			musb_writew(epio, MUSB_RXCSR, csr);
547 		}
548 	}
549 
550 	tdbit = 1 << cppi41_channel->port_num;
551 	if (is_tx)
552 		tdbit <<= 16;
553 
554 	do {
555 		if (is_tx)
556 			musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
557 		ret = dmaengine_terminate_all(cppi41_channel->dc);
558 	} while (ret == -EAGAIN);
559 
560 	if (is_tx) {
561 		musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
562 
563 		csr = musb_readw(epio, MUSB_TXCSR);
564 		if (csr & MUSB_TXCSR_TXPKTRDY) {
565 			csr |= MUSB_TXCSR_FLUSHFIFO;
566 			musb_writew(epio, MUSB_TXCSR, csr);
567 		}
568 	}
569 
570 	cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
571 	return 0;
572 }
573 
574 static void cppi41_release_all_dma_chans(struct cppi41_dma_controller *ctrl)
575 {
576 	struct dma_chan *dc;
577 	int i;
578 
579 	for (i = 0; i < MUSB_DMA_NUM_CHANNELS; i++) {
580 		dc = ctrl->tx_channel[i].dc;
581 		if (dc)
582 			dma_release_channel(dc);
583 		dc = ctrl->rx_channel[i].dc;
584 		if (dc)
585 			dma_release_channel(dc);
586 	}
587 }
588 
589 static void cppi41_dma_controller_stop(struct cppi41_dma_controller *controller)
590 {
591 	cppi41_release_all_dma_chans(controller);
592 }
593 
594 static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
595 {
596 	struct musb *musb = controller->musb;
597 	struct device *dev = musb->controller;
598 	struct device_node *np = dev->parent->of_node;
599 	struct cppi41_dma_channel *cppi41_channel;
600 	int count;
601 	int i;
602 	int ret;
603 
604 	count = of_property_count_strings(np, "dma-names");
605 	if (count < 0)
606 		return count;
607 
608 	for (i = 0; i < count; i++) {
609 		struct dma_chan *dc;
610 		struct dma_channel *musb_dma;
611 		const char *str;
612 		unsigned is_tx;
613 		unsigned int port;
614 
615 		ret = of_property_read_string_index(np, "dma-names", i, &str);
616 		if (ret)
617 			goto err;
618 		if (strstarts(str, "tx"))
619 			is_tx = 1;
620 		else if (strstarts(str, "rx"))
621 			is_tx = 0;
622 		else {
623 			dev_err(dev, "Wrong dmatype %s\n", str);
624 			goto err;
625 		}
626 		ret = kstrtouint(str + 2, 0, &port);
627 		if (ret)
628 			goto err;
629 
630 		ret = -EINVAL;
631 		if (port > MUSB_DMA_NUM_CHANNELS || !port)
632 			goto err;
633 		if (is_tx)
634 			cppi41_channel = &controller->tx_channel[port - 1];
635 		else
636 			cppi41_channel = &controller->rx_channel[port - 1];
637 
638 		cppi41_channel->controller = controller;
639 		cppi41_channel->port_num = port;
640 		cppi41_channel->is_tx = is_tx;
641 		INIT_LIST_HEAD(&cppi41_channel->tx_check);
642 
643 		musb_dma = &cppi41_channel->channel;
644 		musb_dma->private_data = cppi41_channel;
645 		musb_dma->status = MUSB_DMA_STATUS_FREE;
646 		musb_dma->max_len = SZ_4M;
647 
648 		dc = dma_request_slave_channel(dev->parent, str);
649 		if (!dc) {
650 			dev_err(dev, "Failed to request %s.\n", str);
651 			ret = -EPROBE_DEFER;
652 			goto err;
653 		}
654 		cppi41_channel->dc = dc;
655 	}
656 	return 0;
657 err:
658 	cppi41_release_all_dma_chans(controller);
659 	return ret;
660 }
661 
662 void cppi41_dma_controller_destroy(struct dma_controller *c)
663 {
664 	struct cppi41_dma_controller *controller = container_of(c,
665 			struct cppi41_dma_controller, controller);
666 
667 	hrtimer_cancel(&controller->early_tx);
668 	cppi41_dma_controller_stop(controller);
669 	kfree(controller);
670 }
671 EXPORT_SYMBOL_GPL(cppi41_dma_controller_destroy);
672 
673 struct dma_controller *
674 cppi41_dma_controller_create(struct musb *musb, void __iomem *base)
675 {
676 	struct cppi41_dma_controller *controller;
677 	int ret = 0;
678 
679 	if (!musb->controller->parent->of_node) {
680 		dev_err(musb->controller, "Need DT for the DMA engine.\n");
681 		return NULL;
682 	}
683 
684 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
685 	if (!controller)
686 		goto kzalloc_fail;
687 
688 	hrtimer_init(&controller->early_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
689 	controller->early_tx.function = cppi41_recheck_tx_req;
690 	INIT_LIST_HEAD(&controller->early_tx_list);
691 	controller->musb = musb;
692 
693 	controller->controller.channel_alloc = cppi41_dma_channel_allocate;
694 	controller->controller.channel_release = cppi41_dma_channel_release;
695 	controller->controller.channel_program = cppi41_dma_channel_program;
696 	controller->controller.channel_abort = cppi41_dma_channel_abort;
697 	controller->controller.is_compatible = cppi41_is_compatible;
698 
699 	ret = cppi41_dma_controller_start(controller);
700 	if (ret)
701 		goto plat_get_fail;
702 	return &controller->controller;
703 
704 plat_get_fail:
705 	kfree(controller);
706 kzalloc_fail:
707 	if (ret == -EPROBE_DEFER)
708 		return ERR_PTR(ret);
709 	return NULL;
710 }
711 EXPORT_SYMBOL_GPL(cppi41_dma_controller_create);
712