xref: /linux/drivers/usb/musb/musb_cppi41.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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 "musb_core.h"
9 
10 #define RNDIS_REG(x) (0x80 + ((x - 1) * 4))
11 
12 #define EP_MODE_AUTOREQ_NONE		0
13 #define EP_MODE_AUTOREQ_ALL_NEOP	1
14 #define EP_MODE_AUTOREQ_ALWAYS		3
15 
16 #define EP_MODE_DMA_TRANSPARENT		0
17 #define EP_MODE_DMA_RNDIS		1
18 #define EP_MODE_DMA_GEN_RNDIS		3
19 
20 #define USB_CTRL_TX_MODE	0x70
21 #define USB_CTRL_RX_MODE	0x74
22 #define USB_CTRL_AUTOREQ	0xd0
23 #define USB_TDOWN		0xd8
24 
25 struct cppi41_dma_channel {
26 	struct dma_channel channel;
27 	struct cppi41_dma_controller *controller;
28 	struct musb_hw_ep *hw_ep;
29 	struct dma_chan *dc;
30 	dma_cookie_t cookie;
31 	u8 port_num;
32 	u8 is_tx;
33 	u8 is_allocated;
34 	u8 usb_toggle;
35 
36 	dma_addr_t buf_addr;
37 	u32 total_len;
38 	u32 prog_len;
39 	u32 transferred;
40 	u32 packet_sz;
41 	struct list_head tx_check;
42 	int tx_zlp;
43 };
44 
45 #define MUSB_DMA_NUM_CHANNELS 15
46 
47 struct cppi41_dma_controller {
48 	struct dma_controller controller;
49 	struct cppi41_dma_channel rx_channel[MUSB_DMA_NUM_CHANNELS];
50 	struct cppi41_dma_channel tx_channel[MUSB_DMA_NUM_CHANNELS];
51 	struct musb *musb;
52 	struct hrtimer early_tx;
53 	struct list_head early_tx_list;
54 	u32 rx_mode;
55 	u32 tx_mode;
56 	u32 auto_req;
57 };
58 
59 static void save_rx_toggle(struct cppi41_dma_channel *cppi41_channel)
60 {
61 	u16 csr;
62 	u8 toggle;
63 
64 	if (cppi41_channel->is_tx)
65 		return;
66 	if (!is_host_active(cppi41_channel->controller->musb))
67 		return;
68 
69 	csr = musb_readw(cppi41_channel->hw_ep->regs, MUSB_RXCSR);
70 	toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0;
71 
72 	cppi41_channel->usb_toggle = toggle;
73 }
74 
75 static void update_rx_toggle(struct cppi41_dma_channel *cppi41_channel)
76 {
77 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
78 	struct musb *musb = hw_ep->musb;
79 	u16 csr;
80 	u8 toggle;
81 
82 	if (cppi41_channel->is_tx)
83 		return;
84 	if (!is_host_active(musb))
85 		return;
86 
87 	musb_ep_select(musb->mregs, hw_ep->epnum);
88 	csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
89 	toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0;
90 
91 	/*
92 	 * AM335x Advisory 1.0.13: Due to internal synchronisation error the
93 	 * data toggle may reset from DATA1 to DATA0 during receiving data from
94 	 * more than one endpoint.
95 	 */
96 	if (!toggle && toggle == cppi41_channel->usb_toggle) {
97 		csr |= MUSB_RXCSR_H_DATATOGGLE | MUSB_RXCSR_H_WR_DATATOGGLE;
98 		musb_writew(cppi41_channel->hw_ep->regs, MUSB_RXCSR, csr);
99 		dev_dbg(cppi41_channel->controller->musb->controller,
100 				"Restoring DATA1 toggle.\n");
101 	}
102 
103 	cppi41_channel->usb_toggle = toggle;
104 }
105 
106 static bool musb_is_tx_fifo_empty(struct musb_hw_ep *hw_ep)
107 {
108 	u8		epnum = hw_ep->epnum;
109 	struct musb	*musb = hw_ep->musb;
110 	void __iomem	*epio = musb->endpoints[epnum].regs;
111 	u16		csr;
112 
113 	musb_ep_select(musb->mregs, hw_ep->epnum);
114 	csr = musb_readw(epio, MUSB_TXCSR);
115 	if (csr & MUSB_TXCSR_TXPKTRDY)
116 		return false;
117 	return true;
118 }
119 
120 static void cppi41_dma_callback(void *private_data);
121 
122 static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
123 {
124 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
125 	struct musb *musb = hw_ep->musb;
126 	void __iomem *epio = hw_ep->regs;
127 	u16 csr;
128 
129 	if (!cppi41_channel->prog_len ||
130 	    (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)) {
131 
132 		/* done, complete */
133 		cppi41_channel->channel.actual_len =
134 			cppi41_channel->transferred;
135 		cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
136 		cppi41_channel->channel.rx_packet_done = true;
137 
138 		/*
139 		 * transmit ZLP using PIO mode for transfers which size is
140 		 * multiple of EP packet size.
141 		 */
142 		if (cppi41_channel->tx_zlp && (cppi41_channel->transferred %
143 					cppi41_channel->packet_sz) == 0) {
144 			musb_ep_select(musb->mregs, hw_ep->epnum);
145 			csr = MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY;
146 			musb_writew(epio, MUSB_TXCSR, csr);
147 		}
148 		musb_dma_completion(musb, hw_ep->epnum, cppi41_channel->is_tx);
149 	} else {
150 		/* next iteration, reload */
151 		struct dma_chan *dc = cppi41_channel->dc;
152 		struct dma_async_tx_descriptor *dma_desc;
153 		enum dma_transfer_direction direction;
154 		u32 remain_bytes;
155 
156 		cppi41_channel->buf_addr += cppi41_channel->packet_sz;
157 
158 		remain_bytes = cppi41_channel->total_len;
159 		remain_bytes -= cppi41_channel->transferred;
160 		remain_bytes = min(remain_bytes, cppi41_channel->packet_sz);
161 		cppi41_channel->prog_len = remain_bytes;
162 
163 		direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV
164 			: DMA_DEV_TO_MEM;
165 		dma_desc = dmaengine_prep_slave_single(dc,
166 				cppi41_channel->buf_addr,
167 				remain_bytes,
168 				direction,
169 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
170 		if (WARN_ON(!dma_desc))
171 			return;
172 
173 		dma_desc->callback = cppi41_dma_callback;
174 		dma_desc->callback_param = &cppi41_channel->channel;
175 		cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
176 		dma_async_issue_pending(dc);
177 
178 		if (!cppi41_channel->is_tx) {
179 			musb_ep_select(musb->mregs, hw_ep->epnum);
180 			csr = musb_readw(epio, MUSB_RXCSR);
181 			csr |= MUSB_RXCSR_H_REQPKT;
182 			musb_writew(epio, MUSB_RXCSR, csr);
183 		}
184 	}
185 }
186 
187 static enum hrtimer_restart cppi41_recheck_tx_req(struct hrtimer *timer)
188 {
189 	struct cppi41_dma_controller *controller;
190 	struct cppi41_dma_channel *cppi41_channel, *n;
191 	struct musb *musb;
192 	unsigned long flags;
193 	enum hrtimer_restart ret = HRTIMER_NORESTART;
194 
195 	controller = container_of(timer, struct cppi41_dma_controller,
196 			early_tx);
197 	musb = controller->musb;
198 
199 	spin_lock_irqsave(&musb->lock, flags);
200 	list_for_each_entry_safe(cppi41_channel, n, &controller->early_tx_list,
201 			tx_check) {
202 		bool empty;
203 		struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
204 
205 		empty = musb_is_tx_fifo_empty(hw_ep);
206 		if (empty) {
207 			list_del_init(&cppi41_channel->tx_check);
208 			cppi41_trans_done(cppi41_channel);
209 		}
210 	}
211 
212 	if (!list_empty(&controller->early_tx_list) &&
213 	    !hrtimer_is_queued(&controller->early_tx)) {
214 		ret = HRTIMER_RESTART;
215 		hrtimer_forward_now(&controller->early_tx,
216 				ktime_set(0, 20 * NSEC_PER_USEC));
217 	}
218 
219 	spin_unlock_irqrestore(&musb->lock, flags);
220 	return ret;
221 }
222 
223 static void cppi41_dma_callback(void *private_data)
224 {
225 	struct dma_channel *channel = private_data;
226 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
227 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
228 	struct cppi41_dma_controller *controller;
229 	struct musb *musb = hw_ep->musb;
230 	unsigned long flags;
231 	struct dma_tx_state txstate;
232 	u32 transferred;
233 	int is_hs = 0;
234 	bool empty;
235 
236 	spin_lock_irqsave(&musb->lock, flags);
237 
238 	dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
239 			&txstate);
240 	transferred = cppi41_channel->prog_len - txstate.residue;
241 	cppi41_channel->transferred += transferred;
242 
243 	dev_dbg(musb->controller, "DMA transfer done on hw_ep=%d bytes=%d/%d\n",
244 		hw_ep->epnum, cppi41_channel->transferred,
245 		cppi41_channel->total_len);
246 
247 	update_rx_toggle(cppi41_channel);
248 
249 	if (cppi41_channel->transferred == cppi41_channel->total_len ||
250 			transferred < cppi41_channel->packet_sz)
251 		cppi41_channel->prog_len = 0;
252 
253 	if (cppi41_channel->is_tx)
254 		empty = musb_is_tx_fifo_empty(hw_ep);
255 
256 	if (!cppi41_channel->is_tx || empty) {
257 		cppi41_trans_done(cppi41_channel);
258 		goto out;
259 	}
260 
261 	/*
262 	 * On AM335x it has been observed that the TX interrupt fires
263 	 * too early that means the TXFIFO is not yet empty but the DMA
264 	 * engine says that it is done with the transfer. We don't
265 	 * receive a FIFO empty interrupt so the only thing we can do is
266 	 * to poll for the bit. On HS it usually takes 2us, on FS around
267 	 * 110us - 150us depending on the transfer size.
268 	 * We spin on HS (no longer than than 25us and setup a timer on
269 	 * FS to check for the bit and complete the transfer.
270 	 */
271 	controller = cppi41_channel->controller;
272 
273 	if (is_host_active(musb)) {
274 		if (musb->port1_status & USB_PORT_STAT_HIGH_SPEED)
275 			is_hs = 1;
276 	} else {
277 		if (musb->g.speed == USB_SPEED_HIGH)
278 			is_hs = 1;
279 	}
280 	if (is_hs) {
281 		unsigned wait = 25;
282 
283 		do {
284 			empty = musb_is_tx_fifo_empty(hw_ep);
285 			if (empty) {
286 				cppi41_trans_done(cppi41_channel);
287 				goto out;
288 			}
289 			wait--;
290 			if (!wait)
291 				break;
292 			cpu_relax();
293 		} while (1);
294 	}
295 	list_add_tail(&cppi41_channel->tx_check,
296 			&controller->early_tx_list);
297 	if (!hrtimer_is_queued(&controller->early_tx)) {
298 		unsigned long usecs = cppi41_channel->total_len / 10;
299 
300 		hrtimer_start_range_ns(&controller->early_tx,
301 				ktime_set(0, usecs * NSEC_PER_USEC),
302 				20 * NSEC_PER_USEC,
303 				HRTIMER_MODE_REL);
304 	}
305 
306 out:
307 	spin_unlock_irqrestore(&musb->lock, flags);
308 }
309 
310 static u32 update_ep_mode(unsigned ep, unsigned mode, u32 old)
311 {
312 	unsigned shift;
313 
314 	shift = (ep - 1) * 2;
315 	old &= ~(3 << shift);
316 	old |= mode << shift;
317 	return old;
318 }
319 
320 static void cppi41_set_dma_mode(struct cppi41_dma_channel *cppi41_channel,
321 		unsigned mode)
322 {
323 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
324 	u32 port;
325 	u32 new_mode;
326 	u32 old_mode;
327 
328 	if (cppi41_channel->is_tx)
329 		old_mode = controller->tx_mode;
330 	else
331 		old_mode = controller->rx_mode;
332 	port = cppi41_channel->port_num;
333 	new_mode = update_ep_mode(port, mode, old_mode);
334 
335 	if (new_mode == old_mode)
336 		return;
337 	if (cppi41_channel->is_tx) {
338 		controller->tx_mode = new_mode;
339 		musb_writel(controller->musb->ctrl_base, USB_CTRL_TX_MODE,
340 				new_mode);
341 	} else {
342 		controller->rx_mode = new_mode;
343 		musb_writel(controller->musb->ctrl_base, USB_CTRL_RX_MODE,
344 				new_mode);
345 	}
346 }
347 
348 static void cppi41_set_autoreq_mode(struct cppi41_dma_channel *cppi41_channel,
349 		unsigned mode)
350 {
351 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
352 	u32 port;
353 	u32 new_mode;
354 	u32 old_mode;
355 
356 	old_mode = controller->auto_req;
357 	port = cppi41_channel->port_num;
358 	new_mode = update_ep_mode(port, mode, old_mode);
359 
360 	if (new_mode == old_mode)
361 		return;
362 	controller->auto_req = new_mode;
363 	musb_writel(controller->musb->ctrl_base, USB_CTRL_AUTOREQ, new_mode);
364 }
365 
366 static bool cppi41_configure_channel(struct dma_channel *channel,
367 				u16 packet_sz, u8 mode,
368 				dma_addr_t dma_addr, u32 len)
369 {
370 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
371 	struct dma_chan *dc = cppi41_channel->dc;
372 	struct dma_async_tx_descriptor *dma_desc;
373 	enum dma_transfer_direction direction;
374 	struct musb *musb = cppi41_channel->controller->musb;
375 	unsigned use_gen_rndis = 0;
376 
377 	dev_dbg(musb->controller,
378 		"configure ep%d/%x packet_sz=%d, mode=%d, dma_addr=0x%llx, len=%d is_tx=%d\n",
379 		cppi41_channel->port_num, RNDIS_REG(cppi41_channel->port_num),
380 		packet_sz, mode, (unsigned long long) dma_addr,
381 		len, cppi41_channel->is_tx);
382 
383 	cppi41_channel->buf_addr = dma_addr;
384 	cppi41_channel->total_len = len;
385 	cppi41_channel->transferred = 0;
386 	cppi41_channel->packet_sz = packet_sz;
387 	cppi41_channel->tx_zlp = (cppi41_channel->is_tx && mode) ? 1 : 0;
388 
389 	/*
390 	 * Due to AM335x' Advisory 1.0.13 we are not allowed to transfer more
391 	 * than max packet size at a time.
392 	 */
393 	if (cppi41_channel->is_tx)
394 		use_gen_rndis = 1;
395 
396 	if (use_gen_rndis) {
397 		/* RNDIS mode */
398 		if (len > packet_sz) {
399 			musb_writel(musb->ctrl_base,
400 				RNDIS_REG(cppi41_channel->port_num), len);
401 			/* gen rndis */
402 			cppi41_set_dma_mode(cppi41_channel,
403 					EP_MODE_DMA_GEN_RNDIS);
404 
405 			/* auto req */
406 			cppi41_set_autoreq_mode(cppi41_channel,
407 					EP_MODE_AUTOREQ_ALL_NEOP);
408 		} else {
409 			musb_writel(musb->ctrl_base,
410 					RNDIS_REG(cppi41_channel->port_num), 0);
411 			cppi41_set_dma_mode(cppi41_channel,
412 					EP_MODE_DMA_TRANSPARENT);
413 			cppi41_set_autoreq_mode(cppi41_channel,
414 					EP_MODE_AUTOREQ_NONE);
415 		}
416 	} else {
417 		/* fallback mode */
418 		cppi41_set_dma_mode(cppi41_channel, EP_MODE_DMA_TRANSPARENT);
419 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);
420 		len = min_t(u32, packet_sz, len);
421 	}
422 	cppi41_channel->prog_len = len;
423 	direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
424 	dma_desc = dmaengine_prep_slave_single(dc, dma_addr, len, direction,
425 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
426 	if (!dma_desc)
427 		return false;
428 
429 	dma_desc->callback = cppi41_dma_callback;
430 	dma_desc->callback_param = channel;
431 	cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
432 	cppi41_channel->channel.rx_packet_done = false;
433 
434 	save_rx_toggle(cppi41_channel);
435 	dma_async_issue_pending(dc);
436 	return true;
437 }
438 
439 static struct dma_channel *cppi41_dma_channel_allocate(struct dma_controller *c,
440 				struct musb_hw_ep *hw_ep, u8 is_tx)
441 {
442 	struct cppi41_dma_controller *controller = container_of(c,
443 			struct cppi41_dma_controller, controller);
444 	struct cppi41_dma_channel *cppi41_channel = NULL;
445 	u8 ch_num = hw_ep->epnum - 1;
446 
447 	if (ch_num >= MUSB_DMA_NUM_CHANNELS)
448 		return NULL;
449 
450 	if (is_tx)
451 		cppi41_channel = &controller->tx_channel[ch_num];
452 	else
453 		cppi41_channel = &controller->rx_channel[ch_num];
454 
455 	if (!cppi41_channel->dc)
456 		return NULL;
457 
458 	if (cppi41_channel->is_allocated)
459 		return NULL;
460 
461 	cppi41_channel->hw_ep = hw_ep;
462 	cppi41_channel->is_allocated = 1;
463 
464 	return &cppi41_channel->channel;
465 }
466 
467 static void cppi41_dma_channel_release(struct dma_channel *channel)
468 {
469 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
470 
471 	if (cppi41_channel->is_allocated) {
472 		cppi41_channel->is_allocated = 0;
473 		channel->status = MUSB_DMA_STATUS_FREE;
474 		channel->actual_len = 0;
475 	}
476 }
477 
478 static int cppi41_dma_channel_program(struct dma_channel *channel,
479 				u16 packet_sz, u8 mode,
480 				dma_addr_t dma_addr, u32 len)
481 {
482 	int ret;
483 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
484 	int hb_mult = 0;
485 
486 	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
487 		channel->status == MUSB_DMA_STATUS_BUSY);
488 
489 	if (is_host_active(cppi41_channel->controller->musb)) {
490 		if (cppi41_channel->is_tx)
491 			hb_mult = cppi41_channel->hw_ep->out_qh->hb_mult;
492 		else
493 			hb_mult = cppi41_channel->hw_ep->in_qh->hb_mult;
494 	}
495 
496 	channel->status = MUSB_DMA_STATUS_BUSY;
497 	channel->actual_len = 0;
498 
499 	if (hb_mult)
500 		packet_sz = hb_mult * (packet_sz & 0x7FF);
501 
502 	ret = cppi41_configure_channel(channel, packet_sz, mode, dma_addr, len);
503 	if (!ret)
504 		channel->status = MUSB_DMA_STATUS_FREE;
505 
506 	return ret;
507 }
508 
509 static int cppi41_is_compatible(struct dma_channel *channel, u16 maxpacket,
510 		void *buf, u32 length)
511 {
512 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
513 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
514 	struct musb *musb = controller->musb;
515 
516 	if (is_host_active(musb)) {
517 		WARN_ON(1);
518 		return 1;
519 	}
520 	if (cppi41_channel->hw_ep->ep_in.type != USB_ENDPOINT_XFER_BULK)
521 		return 0;
522 	if (cppi41_channel->is_tx)
523 		return 1;
524 	/* AM335x Advisory 1.0.13. No workaround for device RX mode */
525 	return 0;
526 }
527 
528 static int cppi41_dma_channel_abort(struct dma_channel *channel)
529 {
530 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
531 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
532 	struct musb *musb = controller->musb;
533 	void __iomem *epio = cppi41_channel->hw_ep->regs;
534 	int tdbit;
535 	int ret;
536 	unsigned is_tx;
537 	u16 csr;
538 
539 	is_tx = cppi41_channel->is_tx;
540 	dev_dbg(musb->controller, "abort channel=%d, is_tx=%d\n",
541 			cppi41_channel->port_num, is_tx);
542 
543 	if (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)
544 		return 0;
545 
546 	list_del_init(&cppi41_channel->tx_check);
547 	if (is_tx) {
548 		csr = musb_readw(epio, MUSB_TXCSR);
549 		csr &= ~MUSB_TXCSR_DMAENAB;
550 		musb_writew(epio, MUSB_TXCSR, csr);
551 	} else {
552 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);
553 
554 		csr = musb_readw(epio, MUSB_RXCSR);
555 		csr &= ~(MUSB_RXCSR_H_REQPKT | MUSB_RXCSR_DMAENAB);
556 		musb_writew(epio, MUSB_RXCSR, csr);
557 
558 		/* wait to drain cppi dma pipe line */
559 		udelay(50);
560 
561 		csr = musb_readw(epio, MUSB_RXCSR);
562 		if (csr & MUSB_RXCSR_RXPKTRDY) {
563 			csr |= MUSB_RXCSR_FLUSHFIFO;
564 			musb_writew(epio, MUSB_RXCSR, csr);
565 			musb_writew(epio, MUSB_RXCSR, csr);
566 		}
567 	}
568 
569 	tdbit = 1 << cppi41_channel->port_num;
570 	if (is_tx)
571 		tdbit <<= 16;
572 
573 	do {
574 		if (is_tx)
575 			musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
576 		ret = dmaengine_terminate_all(cppi41_channel->dc);
577 	} while (ret == -EAGAIN);
578 
579 	if (is_tx) {
580 		musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
581 
582 		csr = musb_readw(epio, MUSB_TXCSR);
583 		if (csr & MUSB_TXCSR_TXPKTRDY) {
584 			csr |= MUSB_TXCSR_FLUSHFIFO;
585 			musb_writew(epio, MUSB_TXCSR, csr);
586 		}
587 	}
588 
589 	cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
590 	return 0;
591 }
592 
593 static void cppi41_release_all_dma_chans(struct cppi41_dma_controller *ctrl)
594 {
595 	struct dma_chan *dc;
596 	int i;
597 
598 	for (i = 0; i < MUSB_DMA_NUM_CHANNELS; i++) {
599 		dc = ctrl->tx_channel[i].dc;
600 		if (dc)
601 			dma_release_channel(dc);
602 		dc = ctrl->rx_channel[i].dc;
603 		if (dc)
604 			dma_release_channel(dc);
605 	}
606 }
607 
608 static void cppi41_dma_controller_stop(struct cppi41_dma_controller *controller)
609 {
610 	cppi41_release_all_dma_chans(controller);
611 }
612 
613 static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
614 {
615 	struct musb *musb = controller->musb;
616 	struct device *dev = musb->controller;
617 	struct device_node *np = dev->of_node;
618 	struct cppi41_dma_channel *cppi41_channel;
619 	int count;
620 	int i;
621 	int ret;
622 
623 	count = of_property_count_strings(np, "dma-names");
624 	if (count < 0)
625 		return count;
626 
627 	for (i = 0; i < count; i++) {
628 		struct dma_chan *dc;
629 		struct dma_channel *musb_dma;
630 		const char *str;
631 		unsigned is_tx;
632 		unsigned int port;
633 
634 		ret = of_property_read_string_index(np, "dma-names", i, &str);
635 		if (ret)
636 			goto err;
637 		if (strstarts(str, "tx"))
638 			is_tx = 1;
639 		else if (strstarts(str, "rx"))
640 			is_tx = 0;
641 		else {
642 			dev_err(dev, "Wrong dmatype %s\n", str);
643 			goto err;
644 		}
645 		ret = kstrtouint(str + 2, 0, &port);
646 		if (ret)
647 			goto err;
648 
649 		ret = -EINVAL;
650 		if (port > MUSB_DMA_NUM_CHANNELS || !port)
651 			goto err;
652 		if (is_tx)
653 			cppi41_channel = &controller->tx_channel[port - 1];
654 		else
655 			cppi41_channel = &controller->rx_channel[port - 1];
656 
657 		cppi41_channel->controller = controller;
658 		cppi41_channel->port_num = port;
659 		cppi41_channel->is_tx = is_tx;
660 		INIT_LIST_HEAD(&cppi41_channel->tx_check);
661 
662 		musb_dma = &cppi41_channel->channel;
663 		musb_dma->private_data = cppi41_channel;
664 		musb_dma->status = MUSB_DMA_STATUS_FREE;
665 		musb_dma->max_len = SZ_4M;
666 
667 		dc = dma_request_slave_channel(dev, str);
668 		if (!dc) {
669 			dev_err(dev, "Failed to request %s.\n", str);
670 			ret = -EPROBE_DEFER;
671 			goto err;
672 		}
673 		cppi41_channel->dc = dc;
674 	}
675 	return 0;
676 err:
677 	cppi41_release_all_dma_chans(controller);
678 	return ret;
679 }
680 
681 void dma_controller_destroy(struct dma_controller *c)
682 {
683 	struct cppi41_dma_controller *controller = container_of(c,
684 			struct cppi41_dma_controller, controller);
685 
686 	hrtimer_cancel(&controller->early_tx);
687 	cppi41_dma_controller_stop(controller);
688 	kfree(controller);
689 }
690 
691 struct dma_controller *dma_controller_create(struct musb *musb,
692 					void __iomem *base)
693 {
694 	struct cppi41_dma_controller *controller;
695 	int ret = 0;
696 
697 	if (!musb->controller->of_node) {
698 		dev_err(musb->controller, "Need DT for the DMA engine.\n");
699 		return NULL;
700 	}
701 
702 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
703 	if (!controller)
704 		goto kzalloc_fail;
705 
706 	hrtimer_init(&controller->early_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
707 	controller->early_tx.function = cppi41_recheck_tx_req;
708 	INIT_LIST_HEAD(&controller->early_tx_list);
709 	controller->musb = musb;
710 
711 	controller->controller.channel_alloc = cppi41_dma_channel_allocate;
712 	controller->controller.channel_release = cppi41_dma_channel_release;
713 	controller->controller.channel_program = cppi41_dma_channel_program;
714 	controller->controller.channel_abort = cppi41_dma_channel_abort;
715 	controller->controller.is_compatible = cppi41_is_compatible;
716 
717 	ret = cppi41_dma_controller_start(controller);
718 	if (ret)
719 		goto plat_get_fail;
720 	return &controller->controller;
721 
722 plat_get_fail:
723 	kfree(controller);
724 kzalloc_fail:
725 	if (ret == -EPROBE_DEFER)
726 		return ERR_PTR(ret);
727 	return NULL;
728 }
729