xref: /openbmc/linux/drivers/usb/musb/musb_cppi41.c (revision 293d5b43)
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,
201 				ktime_set(0, 20 * NSEC_PER_USEC));
202 	}
203 
204 	spin_unlock_irqrestore(&musb->lock, flags);
205 	return ret;
206 }
207 
208 static void cppi41_dma_callback(void *private_data)
209 {
210 	struct dma_channel *channel = private_data;
211 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
212 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
213 	struct cppi41_dma_controller *controller;
214 	struct musb *musb = hw_ep->musb;
215 	unsigned long flags;
216 	struct dma_tx_state txstate;
217 	u32 transferred;
218 	int is_hs = 0;
219 	bool empty;
220 
221 	spin_lock_irqsave(&musb->lock, flags);
222 
223 	dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
224 			&txstate);
225 	transferred = cppi41_channel->prog_len - txstate.residue;
226 	cppi41_channel->transferred += transferred;
227 
228 	trace_musb_cppi41_gb(cppi41_channel);
229 	update_rx_toggle(cppi41_channel);
230 
231 	if (cppi41_channel->transferred == cppi41_channel->total_len ||
232 			transferred < cppi41_channel->packet_sz)
233 		cppi41_channel->prog_len = 0;
234 
235 	if (cppi41_channel->is_tx)
236 		empty = musb_is_tx_fifo_empty(hw_ep);
237 
238 	if (!cppi41_channel->is_tx || empty) {
239 		cppi41_trans_done(cppi41_channel);
240 		goto out;
241 	}
242 
243 	/*
244 	 * On AM335x it has been observed that the TX interrupt fires
245 	 * too early that means the TXFIFO is not yet empty but the DMA
246 	 * engine says that it is done with the transfer. We don't
247 	 * receive a FIFO empty interrupt so the only thing we can do is
248 	 * to poll for the bit. On HS it usually takes 2us, on FS around
249 	 * 110us - 150us depending on the transfer size.
250 	 * We spin on HS (no longer than than 25us and setup a timer on
251 	 * FS to check for the bit and complete the transfer.
252 	 */
253 	controller = cppi41_channel->controller;
254 
255 	if (is_host_active(musb)) {
256 		if (musb->port1_status & USB_PORT_STAT_HIGH_SPEED)
257 			is_hs = 1;
258 	} else {
259 		if (musb->g.speed == USB_SPEED_HIGH)
260 			is_hs = 1;
261 	}
262 	if (is_hs) {
263 		unsigned wait = 25;
264 
265 		do {
266 			empty = musb_is_tx_fifo_empty(hw_ep);
267 			if (empty) {
268 				cppi41_trans_done(cppi41_channel);
269 				goto out;
270 			}
271 			wait--;
272 			if (!wait)
273 				break;
274 			cpu_relax();
275 		} while (1);
276 	}
277 	list_add_tail(&cppi41_channel->tx_check,
278 			&controller->early_tx_list);
279 	if (!hrtimer_is_queued(&controller->early_tx)) {
280 		unsigned long usecs = cppi41_channel->total_len / 10;
281 
282 		hrtimer_start_range_ns(&controller->early_tx,
283 				ktime_set(0, usecs * NSEC_PER_USEC),
284 				20 * NSEC_PER_USEC,
285 				HRTIMER_MODE_REL);
286 	}
287 
288 out:
289 	spin_unlock_irqrestore(&musb->lock, flags);
290 }
291 
292 static u32 update_ep_mode(unsigned ep, unsigned mode, u32 old)
293 {
294 	unsigned shift;
295 
296 	shift = (ep - 1) * 2;
297 	old &= ~(3 << shift);
298 	old |= mode << shift;
299 	return old;
300 }
301 
302 static void cppi41_set_dma_mode(struct cppi41_dma_channel *cppi41_channel,
303 		unsigned mode)
304 {
305 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
306 	u32 port;
307 	u32 new_mode;
308 	u32 old_mode;
309 
310 	if (cppi41_channel->is_tx)
311 		old_mode = controller->tx_mode;
312 	else
313 		old_mode = controller->rx_mode;
314 	port = cppi41_channel->port_num;
315 	new_mode = update_ep_mode(port, mode, old_mode);
316 
317 	if (new_mode == old_mode)
318 		return;
319 	if (cppi41_channel->is_tx) {
320 		controller->tx_mode = new_mode;
321 		musb_writel(controller->musb->ctrl_base, USB_CTRL_TX_MODE,
322 				new_mode);
323 	} else {
324 		controller->rx_mode = new_mode;
325 		musb_writel(controller->musb->ctrl_base, USB_CTRL_RX_MODE,
326 				new_mode);
327 	}
328 }
329 
330 static void cppi41_set_autoreq_mode(struct cppi41_dma_channel *cppi41_channel,
331 		unsigned mode)
332 {
333 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
334 	u32 port;
335 	u32 new_mode;
336 	u32 old_mode;
337 
338 	old_mode = controller->auto_req;
339 	port = cppi41_channel->port_num;
340 	new_mode = update_ep_mode(port, mode, old_mode);
341 
342 	if (new_mode == old_mode)
343 		return;
344 	controller->auto_req = new_mode;
345 	musb_writel(controller->musb->ctrl_base, USB_CTRL_AUTOREQ, new_mode);
346 }
347 
348 static bool cppi41_configure_channel(struct dma_channel *channel,
349 				u16 packet_sz, u8 mode,
350 				dma_addr_t dma_addr, u32 len)
351 {
352 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
353 	struct dma_chan *dc = cppi41_channel->dc;
354 	struct dma_async_tx_descriptor *dma_desc;
355 	enum dma_transfer_direction direction;
356 	struct musb *musb = cppi41_channel->controller->musb;
357 	unsigned use_gen_rndis = 0;
358 
359 	cppi41_channel->buf_addr = dma_addr;
360 	cppi41_channel->total_len = len;
361 	cppi41_channel->transferred = 0;
362 	cppi41_channel->packet_sz = packet_sz;
363 	cppi41_channel->tx_zlp = (cppi41_channel->is_tx && mode) ? 1 : 0;
364 
365 	/*
366 	 * Due to AM335x' Advisory 1.0.13 we are not allowed to transfer more
367 	 * than max packet size at a time.
368 	 */
369 	if (cppi41_channel->is_tx)
370 		use_gen_rndis = 1;
371 
372 	if (use_gen_rndis) {
373 		/* RNDIS mode */
374 		if (len > packet_sz) {
375 			musb_writel(musb->ctrl_base,
376 				RNDIS_REG(cppi41_channel->port_num), len);
377 			/* gen rndis */
378 			cppi41_set_dma_mode(cppi41_channel,
379 					EP_MODE_DMA_GEN_RNDIS);
380 
381 			/* auto req */
382 			cppi41_set_autoreq_mode(cppi41_channel,
383 					EP_MODE_AUTOREQ_ALL_NEOP);
384 		} else {
385 			musb_writel(musb->ctrl_base,
386 					RNDIS_REG(cppi41_channel->port_num), 0);
387 			cppi41_set_dma_mode(cppi41_channel,
388 					EP_MODE_DMA_TRANSPARENT);
389 			cppi41_set_autoreq_mode(cppi41_channel,
390 					EP_MODE_AUTOREQ_NONE);
391 		}
392 	} else {
393 		/* fallback mode */
394 		cppi41_set_dma_mode(cppi41_channel, EP_MODE_DMA_TRANSPARENT);
395 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);
396 		len = min_t(u32, packet_sz, len);
397 	}
398 	cppi41_channel->prog_len = len;
399 	direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
400 	dma_desc = dmaengine_prep_slave_single(dc, dma_addr, len, direction,
401 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
402 	if (!dma_desc)
403 		return false;
404 
405 	dma_desc->callback = cppi41_dma_callback;
406 	dma_desc->callback_param = channel;
407 	cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
408 	cppi41_channel->channel.rx_packet_done = false;
409 
410 	trace_musb_cppi41_config(cppi41_channel);
411 
412 	save_rx_toggle(cppi41_channel);
413 	dma_async_issue_pending(dc);
414 	return true;
415 }
416 
417 static struct dma_channel *cppi41_dma_channel_allocate(struct dma_controller *c,
418 				struct musb_hw_ep *hw_ep, u8 is_tx)
419 {
420 	struct cppi41_dma_controller *controller = container_of(c,
421 			struct cppi41_dma_controller, controller);
422 	struct cppi41_dma_channel *cppi41_channel = NULL;
423 	u8 ch_num = hw_ep->epnum - 1;
424 
425 	if (ch_num >= MUSB_DMA_NUM_CHANNELS)
426 		return NULL;
427 
428 	if (is_tx)
429 		cppi41_channel = &controller->tx_channel[ch_num];
430 	else
431 		cppi41_channel = &controller->rx_channel[ch_num];
432 
433 	if (!cppi41_channel->dc)
434 		return NULL;
435 
436 	if (cppi41_channel->is_allocated)
437 		return NULL;
438 
439 	cppi41_channel->hw_ep = hw_ep;
440 	cppi41_channel->is_allocated = 1;
441 
442 	trace_musb_cppi41_alloc(cppi41_channel);
443 	return &cppi41_channel->channel;
444 }
445 
446 static void cppi41_dma_channel_release(struct dma_channel *channel)
447 {
448 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
449 
450 	trace_musb_cppi41_free(cppi41_channel);
451 	if (cppi41_channel->is_allocated) {
452 		cppi41_channel->is_allocated = 0;
453 		channel->status = MUSB_DMA_STATUS_FREE;
454 		channel->actual_len = 0;
455 	}
456 }
457 
458 static int cppi41_dma_channel_program(struct dma_channel *channel,
459 				u16 packet_sz, u8 mode,
460 				dma_addr_t dma_addr, u32 len)
461 {
462 	int ret;
463 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
464 	int hb_mult = 0;
465 
466 	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
467 		channel->status == MUSB_DMA_STATUS_BUSY);
468 
469 	if (is_host_active(cppi41_channel->controller->musb)) {
470 		if (cppi41_channel->is_tx)
471 			hb_mult = cppi41_channel->hw_ep->out_qh->hb_mult;
472 		else
473 			hb_mult = cppi41_channel->hw_ep->in_qh->hb_mult;
474 	}
475 
476 	channel->status = MUSB_DMA_STATUS_BUSY;
477 	channel->actual_len = 0;
478 
479 	if (hb_mult)
480 		packet_sz = hb_mult * (packet_sz & 0x7FF);
481 
482 	ret = cppi41_configure_channel(channel, packet_sz, mode, dma_addr, len);
483 	if (!ret)
484 		channel->status = MUSB_DMA_STATUS_FREE;
485 
486 	return ret;
487 }
488 
489 static int cppi41_is_compatible(struct dma_channel *channel, u16 maxpacket,
490 		void *buf, u32 length)
491 {
492 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
493 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
494 	struct musb *musb = controller->musb;
495 
496 	if (is_host_active(musb)) {
497 		WARN_ON(1);
498 		return 1;
499 	}
500 	if (cppi41_channel->hw_ep->ep_in.type != USB_ENDPOINT_XFER_BULK)
501 		return 0;
502 	if (cppi41_channel->is_tx)
503 		return 1;
504 	/* AM335x Advisory 1.0.13. No workaround for device RX mode */
505 	return 0;
506 }
507 
508 static int cppi41_dma_channel_abort(struct dma_channel *channel)
509 {
510 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
511 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
512 	struct musb *musb = controller->musb;
513 	void __iomem *epio = cppi41_channel->hw_ep->regs;
514 	int tdbit;
515 	int ret;
516 	unsigned is_tx;
517 	u16 csr;
518 
519 	is_tx = cppi41_channel->is_tx;
520 	trace_musb_cppi41_abort(cppi41_channel);
521 
522 	if (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)
523 		return 0;
524 
525 	list_del_init(&cppi41_channel->tx_check);
526 	if (is_tx) {
527 		csr = musb_readw(epio, MUSB_TXCSR);
528 		csr &= ~MUSB_TXCSR_DMAENAB;
529 		musb_writew(epio, MUSB_TXCSR, csr);
530 	} else {
531 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);
532 
533 		/* delay to drain to cppi dma pipeline for isoch */
534 		udelay(250);
535 
536 		csr = musb_readw(epio, MUSB_RXCSR);
537 		csr &= ~(MUSB_RXCSR_H_REQPKT | MUSB_RXCSR_DMAENAB);
538 		musb_writew(epio, MUSB_RXCSR, csr);
539 
540 		/* wait to drain cppi dma pipe line */
541 		udelay(50);
542 
543 		csr = musb_readw(epio, MUSB_RXCSR);
544 		if (csr & MUSB_RXCSR_RXPKTRDY) {
545 			csr |= MUSB_RXCSR_FLUSHFIFO;
546 			musb_writew(epio, MUSB_RXCSR, csr);
547 			musb_writew(epio, MUSB_RXCSR, csr);
548 		}
549 	}
550 
551 	tdbit = 1 << cppi41_channel->port_num;
552 	if (is_tx)
553 		tdbit <<= 16;
554 
555 	do {
556 		if (is_tx)
557 			musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
558 		ret = dmaengine_terminate_all(cppi41_channel->dc);
559 	} while (ret == -EAGAIN);
560 
561 	if (is_tx) {
562 		musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
563 
564 		csr = musb_readw(epio, MUSB_TXCSR);
565 		if (csr & MUSB_TXCSR_TXPKTRDY) {
566 			csr |= MUSB_TXCSR_FLUSHFIFO;
567 			musb_writew(epio, MUSB_TXCSR, csr);
568 		}
569 	}
570 
571 	cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
572 	return 0;
573 }
574 
575 static void cppi41_release_all_dma_chans(struct cppi41_dma_controller *ctrl)
576 {
577 	struct dma_chan *dc;
578 	int i;
579 
580 	for (i = 0; i < MUSB_DMA_NUM_CHANNELS; i++) {
581 		dc = ctrl->tx_channel[i].dc;
582 		if (dc)
583 			dma_release_channel(dc);
584 		dc = ctrl->rx_channel[i].dc;
585 		if (dc)
586 			dma_release_channel(dc);
587 	}
588 }
589 
590 static void cppi41_dma_controller_stop(struct cppi41_dma_controller *controller)
591 {
592 	cppi41_release_all_dma_chans(controller);
593 }
594 
595 static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
596 {
597 	struct musb *musb = controller->musb;
598 	struct device *dev = musb->controller;
599 	struct device_node *np = dev->parent->of_node;
600 	struct cppi41_dma_channel *cppi41_channel;
601 	int count;
602 	int i;
603 	int ret;
604 
605 	count = of_property_count_strings(np, "dma-names");
606 	if (count < 0)
607 		return count;
608 
609 	for (i = 0; i < count; i++) {
610 		struct dma_chan *dc;
611 		struct dma_channel *musb_dma;
612 		const char *str;
613 		unsigned is_tx;
614 		unsigned int port;
615 
616 		ret = of_property_read_string_index(np, "dma-names", i, &str);
617 		if (ret)
618 			goto err;
619 		if (strstarts(str, "tx"))
620 			is_tx = 1;
621 		else if (strstarts(str, "rx"))
622 			is_tx = 0;
623 		else {
624 			dev_err(dev, "Wrong dmatype %s\n", str);
625 			goto err;
626 		}
627 		ret = kstrtouint(str + 2, 0, &port);
628 		if (ret)
629 			goto err;
630 
631 		ret = -EINVAL;
632 		if (port > MUSB_DMA_NUM_CHANNELS || !port)
633 			goto err;
634 		if (is_tx)
635 			cppi41_channel = &controller->tx_channel[port - 1];
636 		else
637 			cppi41_channel = &controller->rx_channel[port - 1];
638 
639 		cppi41_channel->controller = controller;
640 		cppi41_channel->port_num = port;
641 		cppi41_channel->is_tx = is_tx;
642 		INIT_LIST_HEAD(&cppi41_channel->tx_check);
643 
644 		musb_dma = &cppi41_channel->channel;
645 		musb_dma->private_data = cppi41_channel;
646 		musb_dma->status = MUSB_DMA_STATUS_FREE;
647 		musb_dma->max_len = SZ_4M;
648 
649 		dc = dma_request_slave_channel(dev->parent, str);
650 		if (!dc) {
651 			dev_err(dev, "Failed to request %s.\n", str);
652 			ret = -EPROBE_DEFER;
653 			goto err;
654 		}
655 		cppi41_channel->dc = dc;
656 	}
657 	return 0;
658 err:
659 	cppi41_release_all_dma_chans(controller);
660 	return ret;
661 }
662 
663 void cppi41_dma_controller_destroy(struct dma_controller *c)
664 {
665 	struct cppi41_dma_controller *controller = container_of(c,
666 			struct cppi41_dma_controller, controller);
667 
668 	hrtimer_cancel(&controller->early_tx);
669 	cppi41_dma_controller_stop(controller);
670 	kfree(controller);
671 }
672 EXPORT_SYMBOL_GPL(cppi41_dma_controller_destroy);
673 
674 struct dma_controller *
675 cppi41_dma_controller_create(struct musb *musb, void __iomem *base)
676 {
677 	struct cppi41_dma_controller *controller;
678 	int ret = 0;
679 
680 	if (!musb->controller->parent->of_node) {
681 		dev_err(musb->controller, "Need DT for the DMA engine.\n");
682 		return NULL;
683 	}
684 
685 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
686 	if (!controller)
687 		goto kzalloc_fail;
688 
689 	hrtimer_init(&controller->early_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
690 	controller->early_tx.function = cppi41_recheck_tx_req;
691 	INIT_LIST_HEAD(&controller->early_tx_list);
692 	controller->musb = musb;
693 
694 	controller->controller.channel_alloc = cppi41_dma_channel_allocate;
695 	controller->controller.channel_release = cppi41_dma_channel_release;
696 	controller->controller.channel_program = cppi41_dma_channel_program;
697 	controller->controller.channel_abort = cppi41_dma_channel_abort;
698 	controller->controller.is_compatible = cppi41_is_compatible;
699 
700 	ret = cppi41_dma_controller_start(controller);
701 	if (ret)
702 		goto plat_get_fail;
703 	return &controller->controller;
704 
705 plat_get_fail:
706 	kfree(controller);
707 kzalloc_fail:
708 	if (ret == -EPROBE_DEFER)
709 		return ERR_PTR(ret);
710 	return NULL;
711 }
712 EXPORT_SYMBOL_GPL(cppi41_dma_controller_create);
713