xref: /openbmc/linux/drivers/usb/musb/musb_cppi41.c (revision afb46f79)
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_AUTOREG_NONE		0
13 #define EP_MODE_AUTOREG_ALL_NEOP	1
14 #define EP_MODE_AUTOREG_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 	struct work_struct dma_completion;
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 	u16 csr;
78 	u8 toggle;
79 
80 	if (cppi41_channel->is_tx)
81 		return;
82 	if (!is_host_active(cppi41_channel->controller->musb))
83 		return;
84 
85 	csr = musb_readw(cppi41_channel->hw_ep->regs, MUSB_RXCSR);
86 	toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0;
87 
88 	/*
89 	 * AM335x Advisory 1.0.13: Due to internal synchronisation error the
90 	 * data toggle may reset from DATA1 to DATA0 during receiving data from
91 	 * more than one endpoint.
92 	 */
93 	if (!toggle && toggle == cppi41_channel->usb_toggle) {
94 		csr |= MUSB_RXCSR_H_DATATOGGLE | MUSB_RXCSR_H_WR_DATATOGGLE;
95 		musb_writew(cppi41_channel->hw_ep->regs, MUSB_RXCSR, csr);
96 		dev_dbg(cppi41_channel->controller->musb->controller,
97 				"Restoring DATA1 toggle.\n");
98 	}
99 
100 	cppi41_channel->usb_toggle = toggle;
101 }
102 
103 static bool musb_is_tx_fifo_empty(struct musb_hw_ep *hw_ep)
104 {
105 	u8		epnum = hw_ep->epnum;
106 	struct musb	*musb = hw_ep->musb;
107 	void __iomem	*epio = musb->endpoints[epnum].regs;
108 	u16		csr;
109 
110 	csr = musb_readw(epio, MUSB_TXCSR);
111 	if (csr & MUSB_TXCSR_TXPKTRDY)
112 		return false;
113 	return true;
114 }
115 
116 static bool is_isoc(struct musb_hw_ep *hw_ep, bool in)
117 {
118 	if (in && hw_ep->in_qh) {
119 		if (hw_ep->in_qh->type == USB_ENDPOINT_XFER_ISOC)
120 			return true;
121 	} else if (hw_ep->out_qh) {
122 		if (hw_ep->out_qh->type == USB_ENDPOINT_XFER_ISOC)
123 			return true;
124 	}
125 	return false;
126 }
127 
128 static void cppi41_dma_callback(void *private_data);
129 
130 static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
131 {
132 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
133 	struct musb *musb = hw_ep->musb;
134 
135 	if (!cppi41_channel->prog_len ||
136 	    (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)) {
137 
138 		/* done, complete */
139 		cppi41_channel->channel.actual_len =
140 			cppi41_channel->transferred;
141 		cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
142 		musb_dma_completion(musb, hw_ep->epnum, cppi41_channel->is_tx);
143 	} else {
144 		/* next iteration, reload */
145 		struct dma_chan *dc = cppi41_channel->dc;
146 		struct dma_async_tx_descriptor *dma_desc;
147 		enum dma_transfer_direction direction;
148 		u16 csr;
149 		u32 remain_bytes;
150 		void __iomem *epio = cppi41_channel->hw_ep->regs;
151 
152 		cppi41_channel->buf_addr += cppi41_channel->packet_sz;
153 
154 		remain_bytes = cppi41_channel->total_len;
155 		remain_bytes -= cppi41_channel->transferred;
156 		remain_bytes = min(remain_bytes, cppi41_channel->packet_sz);
157 		cppi41_channel->prog_len = remain_bytes;
158 
159 		direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV
160 			: DMA_DEV_TO_MEM;
161 		dma_desc = dmaengine_prep_slave_single(dc,
162 				cppi41_channel->buf_addr,
163 				remain_bytes,
164 				direction,
165 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
166 		if (WARN_ON(!dma_desc))
167 			return;
168 
169 		dma_desc->callback = cppi41_dma_callback;
170 		dma_desc->callback_param = &cppi41_channel->channel;
171 		cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
172 		dma_async_issue_pending(dc);
173 
174 		if (!cppi41_channel->is_tx) {
175 			csr = musb_readw(epio, MUSB_RXCSR);
176 			csr |= MUSB_RXCSR_H_REQPKT;
177 			musb_writew(epio, MUSB_RXCSR, csr);
178 		}
179 	}
180 }
181 
182 static void cppi_trans_done_work(struct work_struct *work)
183 {
184 	unsigned long flags;
185 	struct cppi41_dma_channel *cppi41_channel =
186 		container_of(work, struct cppi41_dma_channel, dma_completion);
187 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
188 	struct musb *musb = controller->musb;
189 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
190 	bool empty;
191 
192 	if (!cppi41_channel->is_tx && is_isoc(hw_ep, 1)) {
193 		spin_lock_irqsave(&musb->lock, flags);
194 		cppi41_trans_done(cppi41_channel);
195 		spin_unlock_irqrestore(&musb->lock, flags);
196 	} else {
197 		empty = musb_is_tx_fifo_empty(hw_ep);
198 		if (empty) {
199 			spin_lock_irqsave(&musb->lock, flags);
200 			cppi41_trans_done(cppi41_channel);
201 			spin_unlock_irqrestore(&musb->lock, flags);
202 		} else {
203 			schedule_work(&cppi41_channel->dma_completion);
204 		}
205 	}
206 }
207 
208 static enum hrtimer_restart cppi41_recheck_tx_req(struct hrtimer *timer)
209 {
210 	struct cppi41_dma_controller *controller;
211 	struct cppi41_dma_channel *cppi41_channel, *n;
212 	struct musb *musb;
213 	unsigned long flags;
214 	enum hrtimer_restart ret = HRTIMER_NORESTART;
215 
216 	controller = container_of(timer, struct cppi41_dma_controller,
217 			early_tx);
218 	musb = controller->musb;
219 
220 	spin_lock_irqsave(&musb->lock, flags);
221 	list_for_each_entry_safe(cppi41_channel, n, &controller->early_tx_list,
222 			tx_check) {
223 		bool empty;
224 		struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
225 
226 		empty = musb_is_tx_fifo_empty(hw_ep);
227 		if (empty) {
228 			list_del_init(&cppi41_channel->tx_check);
229 			cppi41_trans_done(cppi41_channel);
230 		}
231 	}
232 
233 	if (!list_empty(&controller->early_tx_list)) {
234 		ret = HRTIMER_RESTART;
235 		hrtimer_forward_now(&controller->early_tx,
236 				ktime_set(0, 150 * NSEC_PER_USEC));
237 	}
238 
239 	spin_unlock_irqrestore(&musb->lock, flags);
240 	return ret;
241 }
242 
243 static void cppi41_dma_callback(void *private_data)
244 {
245 	struct dma_channel *channel = private_data;
246 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
247 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
248 	struct musb *musb = hw_ep->musb;
249 	unsigned long flags;
250 	struct dma_tx_state txstate;
251 	u32 transferred;
252 	bool empty;
253 
254 	spin_lock_irqsave(&musb->lock, flags);
255 
256 	dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
257 			&txstate);
258 	transferred = cppi41_channel->prog_len - txstate.residue;
259 	cppi41_channel->transferred += transferred;
260 
261 	dev_dbg(musb->controller, "DMA transfer done on hw_ep=%d bytes=%d/%d\n",
262 		hw_ep->epnum, cppi41_channel->transferred,
263 		cppi41_channel->total_len);
264 
265 	update_rx_toggle(cppi41_channel);
266 
267 	if (cppi41_channel->transferred == cppi41_channel->total_len ||
268 			transferred < cppi41_channel->packet_sz)
269 		cppi41_channel->prog_len = 0;
270 
271 	if (!cppi41_channel->is_tx) {
272 		if (is_isoc(hw_ep, 1))
273 			schedule_work(&cppi41_channel->dma_completion);
274 		else
275 			cppi41_trans_done(cppi41_channel);
276 		goto out;
277 	}
278 
279 	empty = musb_is_tx_fifo_empty(hw_ep);
280 	if (empty) {
281 		cppi41_trans_done(cppi41_channel);
282 	} else {
283 		struct cppi41_dma_controller *controller;
284 		/*
285 		 * On AM335x it has been observed that the TX interrupt fires
286 		 * too early that means the TXFIFO is not yet empty but the DMA
287 		 * engine says that it is done with the transfer. We don't
288 		 * receive a FIFO empty interrupt so the only thing we can do is
289 		 * to poll for the bit. On HS it usually takes 2us, on FS around
290 		 * 110us - 150us depending on the transfer size.
291 		 * We spin on HS (no longer than than 25us and setup a timer on
292 		 * FS to check for the bit and complete the transfer.
293 		 */
294 		controller = cppi41_channel->controller;
295 
296 		if (musb->g.speed == USB_SPEED_HIGH) {
297 			unsigned wait = 25;
298 
299 			do {
300 				empty = musb_is_tx_fifo_empty(hw_ep);
301 				if (empty)
302 					break;
303 				wait--;
304 				if (!wait)
305 					break;
306 				udelay(1);
307 			} while (1);
308 
309 			empty = musb_is_tx_fifo_empty(hw_ep);
310 			if (empty) {
311 				cppi41_trans_done(cppi41_channel);
312 				goto out;
313 			}
314 		}
315 		if (is_isoc(hw_ep, 0)) {
316 			schedule_work(&cppi41_channel->dma_completion);
317 			goto out;
318 		}
319 		list_add_tail(&cppi41_channel->tx_check,
320 				&controller->early_tx_list);
321 		if (!hrtimer_active(&controller->early_tx)) {
322 			hrtimer_start_range_ns(&controller->early_tx,
323 				ktime_set(0, 140 * NSEC_PER_USEC),
324 				40 * NSEC_PER_USEC,
325 				HRTIMER_MODE_REL);
326 		}
327 	}
328 out:
329 	spin_unlock_irqrestore(&musb->lock, flags);
330 }
331 
332 static u32 update_ep_mode(unsigned ep, unsigned mode, u32 old)
333 {
334 	unsigned shift;
335 
336 	shift = (ep - 1) * 2;
337 	old &= ~(3 << shift);
338 	old |= mode << shift;
339 	return old;
340 }
341 
342 static void cppi41_set_dma_mode(struct cppi41_dma_channel *cppi41_channel,
343 		unsigned mode)
344 {
345 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
346 	u32 port;
347 	u32 new_mode;
348 	u32 old_mode;
349 
350 	if (cppi41_channel->is_tx)
351 		old_mode = controller->tx_mode;
352 	else
353 		old_mode = controller->rx_mode;
354 	port = cppi41_channel->port_num;
355 	new_mode = update_ep_mode(port, mode, old_mode);
356 
357 	if (new_mode == old_mode)
358 		return;
359 	if (cppi41_channel->is_tx) {
360 		controller->tx_mode = new_mode;
361 		musb_writel(controller->musb->ctrl_base, USB_CTRL_TX_MODE,
362 				new_mode);
363 	} else {
364 		controller->rx_mode = new_mode;
365 		musb_writel(controller->musb->ctrl_base, USB_CTRL_RX_MODE,
366 				new_mode);
367 	}
368 }
369 
370 static void cppi41_set_autoreq_mode(struct cppi41_dma_channel *cppi41_channel,
371 		unsigned mode)
372 {
373 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
374 	u32 port;
375 	u32 new_mode;
376 	u32 old_mode;
377 
378 	old_mode = controller->auto_req;
379 	port = cppi41_channel->port_num;
380 	new_mode = update_ep_mode(port, mode, old_mode);
381 
382 	if (new_mode == old_mode)
383 		return;
384 	controller->auto_req = new_mode;
385 	musb_writel(controller->musb->ctrl_base, USB_CTRL_AUTOREQ, new_mode);
386 }
387 
388 static bool cppi41_configure_channel(struct dma_channel *channel,
389 				u16 packet_sz, u8 mode,
390 				dma_addr_t dma_addr, u32 len)
391 {
392 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
393 	struct dma_chan *dc = cppi41_channel->dc;
394 	struct dma_async_tx_descriptor *dma_desc;
395 	enum dma_transfer_direction direction;
396 	struct musb *musb = cppi41_channel->controller->musb;
397 	unsigned use_gen_rndis = 0;
398 
399 	dev_dbg(musb->controller,
400 		"configure ep%d/%x packet_sz=%d, mode=%d, dma_addr=0x%llx, len=%d is_tx=%d\n",
401 		cppi41_channel->port_num, RNDIS_REG(cppi41_channel->port_num),
402 		packet_sz, mode, (unsigned long long) dma_addr,
403 		len, cppi41_channel->is_tx);
404 
405 	cppi41_channel->buf_addr = dma_addr;
406 	cppi41_channel->total_len = len;
407 	cppi41_channel->transferred = 0;
408 	cppi41_channel->packet_sz = packet_sz;
409 
410 	/*
411 	 * Due to AM335x' Advisory 1.0.13 we are not allowed to transfer more
412 	 * than max packet size at a time.
413 	 */
414 	if (cppi41_channel->is_tx)
415 		use_gen_rndis = 1;
416 
417 	if (use_gen_rndis) {
418 		/* RNDIS mode */
419 		if (len > packet_sz) {
420 			musb_writel(musb->ctrl_base,
421 				RNDIS_REG(cppi41_channel->port_num), len);
422 			/* gen rndis */
423 			cppi41_set_dma_mode(cppi41_channel,
424 					EP_MODE_DMA_GEN_RNDIS);
425 
426 			/* auto req */
427 			cppi41_set_autoreq_mode(cppi41_channel,
428 					EP_MODE_AUTOREG_ALL_NEOP);
429 		} else {
430 			musb_writel(musb->ctrl_base,
431 					RNDIS_REG(cppi41_channel->port_num), 0);
432 			cppi41_set_dma_mode(cppi41_channel,
433 					EP_MODE_DMA_TRANSPARENT);
434 			cppi41_set_autoreq_mode(cppi41_channel,
435 					EP_MODE_AUTOREG_NONE);
436 		}
437 	} else {
438 		/* fallback mode */
439 		cppi41_set_dma_mode(cppi41_channel, EP_MODE_DMA_TRANSPARENT);
440 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREG_NONE);
441 		len = min_t(u32, packet_sz, len);
442 	}
443 	cppi41_channel->prog_len = len;
444 	direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
445 	dma_desc = dmaengine_prep_slave_single(dc, dma_addr, len, direction,
446 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
447 	if (!dma_desc)
448 		return false;
449 
450 	dma_desc->callback = cppi41_dma_callback;
451 	dma_desc->callback_param = channel;
452 	cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
453 
454 	save_rx_toggle(cppi41_channel);
455 	dma_async_issue_pending(dc);
456 	return true;
457 }
458 
459 static struct dma_channel *cppi41_dma_channel_allocate(struct dma_controller *c,
460 				struct musb_hw_ep *hw_ep, u8 is_tx)
461 {
462 	struct cppi41_dma_controller *controller = container_of(c,
463 			struct cppi41_dma_controller, controller);
464 	struct cppi41_dma_channel *cppi41_channel = NULL;
465 	u8 ch_num = hw_ep->epnum - 1;
466 
467 	if (ch_num >= MUSB_DMA_NUM_CHANNELS)
468 		return NULL;
469 
470 	if (is_tx)
471 		cppi41_channel = &controller->tx_channel[ch_num];
472 	else
473 		cppi41_channel = &controller->rx_channel[ch_num];
474 
475 	if (!cppi41_channel->dc)
476 		return NULL;
477 
478 	if (cppi41_channel->is_allocated)
479 		return NULL;
480 
481 	cppi41_channel->hw_ep = hw_ep;
482 	cppi41_channel->is_allocated = 1;
483 
484 	return &cppi41_channel->channel;
485 }
486 
487 static void cppi41_dma_channel_release(struct dma_channel *channel)
488 {
489 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
490 
491 	if (cppi41_channel->is_allocated) {
492 		cppi41_channel->is_allocated = 0;
493 		channel->status = MUSB_DMA_STATUS_FREE;
494 		channel->actual_len = 0;
495 	}
496 }
497 
498 static int cppi41_dma_channel_program(struct dma_channel *channel,
499 				u16 packet_sz, u8 mode,
500 				dma_addr_t dma_addr, u32 len)
501 {
502 	int ret;
503 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
504 	int hb_mult = 0;
505 
506 	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
507 		channel->status == MUSB_DMA_STATUS_BUSY);
508 
509 	if (is_host_active(cppi41_channel->controller->musb)) {
510 		if (cppi41_channel->is_tx)
511 			hb_mult = cppi41_channel->hw_ep->out_qh->hb_mult;
512 		else
513 			hb_mult = cppi41_channel->hw_ep->in_qh->hb_mult;
514 	}
515 
516 	channel->status = MUSB_DMA_STATUS_BUSY;
517 	channel->actual_len = 0;
518 
519 	if (hb_mult)
520 		packet_sz = hb_mult * (packet_sz & 0x7FF);
521 
522 	ret = cppi41_configure_channel(channel, packet_sz, mode, dma_addr, len);
523 	if (!ret)
524 		channel->status = MUSB_DMA_STATUS_FREE;
525 
526 	return ret;
527 }
528 
529 static int cppi41_is_compatible(struct dma_channel *channel, u16 maxpacket,
530 		void *buf, u32 length)
531 {
532 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
533 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
534 	struct musb *musb = controller->musb;
535 
536 	if (is_host_active(musb)) {
537 		WARN_ON(1);
538 		return 1;
539 	}
540 	if (cppi41_channel->hw_ep->ep_in.type != USB_ENDPOINT_XFER_BULK)
541 		return 0;
542 	if (cppi41_channel->is_tx)
543 		return 1;
544 	/* AM335x Advisory 1.0.13. No workaround for device RX mode */
545 	return 0;
546 }
547 
548 static int cppi41_dma_channel_abort(struct dma_channel *channel)
549 {
550 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
551 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
552 	struct musb *musb = controller->musb;
553 	void __iomem *epio = cppi41_channel->hw_ep->regs;
554 	int tdbit;
555 	int ret;
556 	unsigned is_tx;
557 	u16 csr;
558 
559 	is_tx = cppi41_channel->is_tx;
560 	dev_dbg(musb->controller, "abort channel=%d, is_tx=%d\n",
561 			cppi41_channel->port_num, is_tx);
562 
563 	if (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)
564 		return 0;
565 
566 	list_del_init(&cppi41_channel->tx_check);
567 	if (is_tx) {
568 		csr = musb_readw(epio, MUSB_TXCSR);
569 		csr &= ~MUSB_TXCSR_DMAENAB;
570 		musb_writew(epio, MUSB_TXCSR, csr);
571 	} else {
572 		csr = musb_readw(epio, MUSB_RXCSR);
573 		csr &= ~(MUSB_RXCSR_H_REQPKT | MUSB_RXCSR_DMAENAB);
574 		musb_writew(epio, MUSB_RXCSR, csr);
575 
576 		csr = musb_readw(epio, MUSB_RXCSR);
577 		if (csr & MUSB_RXCSR_RXPKTRDY) {
578 			csr |= MUSB_RXCSR_FLUSHFIFO;
579 			musb_writew(epio, MUSB_RXCSR, csr);
580 			musb_writew(epio, MUSB_RXCSR, csr);
581 		}
582 	}
583 
584 	tdbit = 1 << cppi41_channel->port_num;
585 	if (is_tx)
586 		tdbit <<= 16;
587 
588 	do {
589 		musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
590 		ret = dmaengine_terminate_all(cppi41_channel->dc);
591 	} while (ret == -EAGAIN);
592 
593 	musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
594 
595 	if (is_tx) {
596 		csr = musb_readw(epio, MUSB_TXCSR);
597 		if (csr & MUSB_TXCSR_TXPKTRDY) {
598 			csr |= MUSB_TXCSR_FLUSHFIFO;
599 			musb_writew(epio, MUSB_TXCSR, csr);
600 		}
601 	}
602 
603 	cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
604 	return 0;
605 }
606 
607 static void cppi41_release_all_dma_chans(struct cppi41_dma_controller *ctrl)
608 {
609 	struct dma_chan *dc;
610 	int i;
611 
612 	for (i = 0; i < MUSB_DMA_NUM_CHANNELS; i++) {
613 		dc = ctrl->tx_channel[i].dc;
614 		if (dc)
615 			dma_release_channel(dc);
616 		dc = ctrl->rx_channel[i].dc;
617 		if (dc)
618 			dma_release_channel(dc);
619 	}
620 }
621 
622 static void cppi41_dma_controller_stop(struct cppi41_dma_controller *controller)
623 {
624 	cppi41_release_all_dma_chans(controller);
625 }
626 
627 static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
628 {
629 	struct musb *musb = controller->musb;
630 	struct device *dev = musb->controller;
631 	struct device_node *np = dev->of_node;
632 	struct cppi41_dma_channel *cppi41_channel;
633 	int count;
634 	int i;
635 	int ret;
636 
637 	count = of_property_count_strings(np, "dma-names");
638 	if (count < 0)
639 		return count;
640 
641 	for (i = 0; i < count; i++) {
642 		struct dma_chan *dc;
643 		struct dma_channel *musb_dma;
644 		const char *str;
645 		unsigned is_tx;
646 		unsigned int port;
647 
648 		ret = of_property_read_string_index(np, "dma-names", i, &str);
649 		if (ret)
650 			goto err;
651 		if (!strncmp(str, "tx", 2))
652 			is_tx = 1;
653 		else if (!strncmp(str, "rx", 2))
654 			is_tx = 0;
655 		else {
656 			dev_err(dev, "Wrong dmatype %s\n", str);
657 			goto err;
658 		}
659 		ret = kstrtouint(str + 2, 0, &port);
660 		if (ret)
661 			goto err;
662 
663 		ret = -EINVAL;
664 		if (port > MUSB_DMA_NUM_CHANNELS || !port)
665 			goto err;
666 		if (is_tx)
667 			cppi41_channel = &controller->tx_channel[port - 1];
668 		else
669 			cppi41_channel = &controller->rx_channel[port - 1];
670 
671 		cppi41_channel->controller = controller;
672 		cppi41_channel->port_num = port;
673 		cppi41_channel->is_tx = is_tx;
674 		INIT_LIST_HEAD(&cppi41_channel->tx_check);
675 		INIT_WORK(&cppi41_channel->dma_completion,
676 			  cppi_trans_done_work);
677 
678 		musb_dma = &cppi41_channel->channel;
679 		musb_dma->private_data = cppi41_channel;
680 		musb_dma->status = MUSB_DMA_STATUS_FREE;
681 		musb_dma->max_len = SZ_4M;
682 
683 		dc = dma_request_slave_channel(dev, str);
684 		if (!dc) {
685 			dev_err(dev, "Failed to request %s.\n", str);
686 			ret = -EPROBE_DEFER;
687 			goto err;
688 		}
689 		cppi41_channel->dc = dc;
690 	}
691 	return 0;
692 err:
693 	cppi41_release_all_dma_chans(controller);
694 	return ret;
695 }
696 
697 void dma_controller_destroy(struct dma_controller *c)
698 {
699 	struct cppi41_dma_controller *controller = container_of(c,
700 			struct cppi41_dma_controller, controller);
701 
702 	hrtimer_cancel(&controller->early_tx);
703 	cppi41_dma_controller_stop(controller);
704 	kfree(controller);
705 }
706 
707 struct dma_controller *dma_controller_create(struct musb *musb,
708 					void __iomem *base)
709 {
710 	struct cppi41_dma_controller *controller;
711 	int ret = 0;
712 
713 	if (!musb->controller->of_node) {
714 		dev_err(musb->controller, "Need DT for the DMA engine.\n");
715 		return NULL;
716 	}
717 
718 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
719 	if (!controller)
720 		goto kzalloc_fail;
721 
722 	hrtimer_init(&controller->early_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
723 	controller->early_tx.function = cppi41_recheck_tx_req;
724 	INIT_LIST_HEAD(&controller->early_tx_list);
725 	controller->musb = musb;
726 
727 	controller->controller.channel_alloc = cppi41_dma_channel_allocate;
728 	controller->controller.channel_release = cppi41_dma_channel_release;
729 	controller->controller.channel_program = cppi41_dma_channel_program;
730 	controller->controller.channel_abort = cppi41_dma_channel_abort;
731 	controller->controller.is_compatible = cppi41_is_compatible;
732 
733 	ret = cppi41_dma_controller_start(controller);
734 	if (ret)
735 		goto plat_get_fail;
736 	return &controller->controller;
737 
738 plat_get_fail:
739 	kfree(controller);
740 kzalloc_fail:
741 	if (ret == -EPROBE_DEFER)
742 		return ERR_PTR(ret);
743 	return NULL;
744 }
745