xref: /openbmc/linux/drivers/usb/musb/musb_cppi41.c (revision 8684014d)
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 	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 musb *musb = hw_ep->musb;
229 	unsigned long flags;
230 	struct dma_tx_state txstate;
231 	u32 transferred;
232 	bool empty;
233 
234 	spin_lock_irqsave(&musb->lock, flags);
235 
236 	dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
237 			&txstate);
238 	transferred = cppi41_channel->prog_len - txstate.residue;
239 	cppi41_channel->transferred += transferred;
240 
241 	dev_dbg(musb->controller, "DMA transfer done on hw_ep=%d bytes=%d/%d\n",
242 		hw_ep->epnum, cppi41_channel->transferred,
243 		cppi41_channel->total_len);
244 
245 	update_rx_toggle(cppi41_channel);
246 
247 	if (cppi41_channel->transferred == cppi41_channel->total_len ||
248 			transferred < cppi41_channel->packet_sz)
249 		cppi41_channel->prog_len = 0;
250 
251 	empty = musb_is_tx_fifo_empty(hw_ep);
252 	if (empty) {
253 		cppi41_trans_done(cppi41_channel);
254 	} else {
255 		struct cppi41_dma_controller *controller;
256 		int is_hs = 0;
257 		/*
258 		 * On AM335x it has been observed that the TX interrupt fires
259 		 * too early that means the TXFIFO is not yet empty but the DMA
260 		 * engine says that it is done with the transfer. We don't
261 		 * receive a FIFO empty interrupt so the only thing we can do is
262 		 * to poll for the bit. On HS it usually takes 2us, on FS around
263 		 * 110us - 150us depending on the transfer size.
264 		 * We spin on HS (no longer than than 25us and setup a timer on
265 		 * FS to check for the bit and complete the transfer.
266 		 */
267 		controller = cppi41_channel->controller;
268 
269 		if (is_host_active(musb)) {
270 			if (musb->port1_status & USB_PORT_STAT_HIGH_SPEED)
271 				is_hs = 1;
272 		} else {
273 			if (musb->g.speed == USB_SPEED_HIGH)
274 				is_hs = 1;
275 		}
276 		if (is_hs) {
277 			unsigned wait = 25;
278 
279 			do {
280 				empty = musb_is_tx_fifo_empty(hw_ep);
281 				if (empty)
282 					break;
283 				wait--;
284 				if (!wait)
285 					break;
286 				udelay(1);
287 			} while (1);
288 
289 			empty = musb_is_tx_fifo_empty(hw_ep);
290 			if (empty) {
291 				cppi41_trans_done(cppi41_channel);
292 				goto out;
293 			}
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_AUTOREG_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_AUTOREG_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_AUTOREG_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 		csr = musb_readw(epio, MUSB_RXCSR);
553 		csr &= ~(MUSB_RXCSR_H_REQPKT | MUSB_RXCSR_DMAENAB);
554 		musb_writew(epio, MUSB_RXCSR, csr);
555 
556 		csr = musb_readw(epio, MUSB_RXCSR);
557 		if (csr & MUSB_RXCSR_RXPKTRDY) {
558 			csr |= MUSB_RXCSR_FLUSHFIFO;
559 			musb_writew(epio, MUSB_RXCSR, csr);
560 			musb_writew(epio, MUSB_RXCSR, csr);
561 		}
562 	}
563 
564 	tdbit = 1 << cppi41_channel->port_num;
565 	if (is_tx)
566 		tdbit <<= 16;
567 
568 	do {
569 		musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
570 		ret = dmaengine_terminate_all(cppi41_channel->dc);
571 	} while (ret == -EAGAIN);
572 
573 	musb_writel(musb->ctrl_base, USB_TDOWN, tdbit);
574 
575 	if (is_tx) {
576 		csr = musb_readw(epio, MUSB_TXCSR);
577 		if (csr & MUSB_TXCSR_TXPKTRDY) {
578 			csr |= MUSB_TXCSR_FLUSHFIFO;
579 			musb_writew(epio, MUSB_TXCSR, csr);
580 		}
581 	}
582 
583 	cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
584 	return 0;
585 }
586 
587 static void cppi41_release_all_dma_chans(struct cppi41_dma_controller *ctrl)
588 {
589 	struct dma_chan *dc;
590 	int i;
591 
592 	for (i = 0; i < MUSB_DMA_NUM_CHANNELS; i++) {
593 		dc = ctrl->tx_channel[i].dc;
594 		if (dc)
595 			dma_release_channel(dc);
596 		dc = ctrl->rx_channel[i].dc;
597 		if (dc)
598 			dma_release_channel(dc);
599 	}
600 }
601 
602 static void cppi41_dma_controller_stop(struct cppi41_dma_controller *controller)
603 {
604 	cppi41_release_all_dma_chans(controller);
605 }
606 
607 static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
608 {
609 	struct musb *musb = controller->musb;
610 	struct device *dev = musb->controller;
611 	struct device_node *np = dev->of_node;
612 	struct cppi41_dma_channel *cppi41_channel;
613 	int count;
614 	int i;
615 	int ret;
616 
617 	count = of_property_count_strings(np, "dma-names");
618 	if (count < 0)
619 		return count;
620 
621 	for (i = 0; i < count; i++) {
622 		struct dma_chan *dc;
623 		struct dma_channel *musb_dma;
624 		const char *str;
625 		unsigned is_tx;
626 		unsigned int port;
627 
628 		ret = of_property_read_string_index(np, "dma-names", i, &str);
629 		if (ret)
630 			goto err;
631 		if (!strncmp(str, "tx", 2))
632 			is_tx = 1;
633 		else if (!strncmp(str, "rx", 2))
634 			is_tx = 0;
635 		else {
636 			dev_err(dev, "Wrong dmatype %s\n", str);
637 			goto err;
638 		}
639 		ret = kstrtouint(str + 2, 0, &port);
640 		if (ret)
641 			goto err;
642 
643 		ret = -EINVAL;
644 		if (port > MUSB_DMA_NUM_CHANNELS || !port)
645 			goto err;
646 		if (is_tx)
647 			cppi41_channel = &controller->tx_channel[port - 1];
648 		else
649 			cppi41_channel = &controller->rx_channel[port - 1];
650 
651 		cppi41_channel->controller = controller;
652 		cppi41_channel->port_num = port;
653 		cppi41_channel->is_tx = is_tx;
654 		INIT_LIST_HEAD(&cppi41_channel->tx_check);
655 
656 		musb_dma = &cppi41_channel->channel;
657 		musb_dma->private_data = cppi41_channel;
658 		musb_dma->status = MUSB_DMA_STATUS_FREE;
659 		musb_dma->max_len = SZ_4M;
660 
661 		dc = dma_request_slave_channel(dev, str);
662 		if (!dc) {
663 			dev_err(dev, "Failed to request %s.\n", str);
664 			ret = -EPROBE_DEFER;
665 			goto err;
666 		}
667 		cppi41_channel->dc = dc;
668 	}
669 	return 0;
670 err:
671 	cppi41_release_all_dma_chans(controller);
672 	return ret;
673 }
674 
675 void dma_controller_destroy(struct dma_controller *c)
676 {
677 	struct cppi41_dma_controller *controller = container_of(c,
678 			struct cppi41_dma_controller, controller);
679 
680 	hrtimer_cancel(&controller->early_tx);
681 	cppi41_dma_controller_stop(controller);
682 	kfree(controller);
683 }
684 
685 struct dma_controller *dma_controller_create(struct musb *musb,
686 					void __iomem *base)
687 {
688 	struct cppi41_dma_controller *controller;
689 	int ret = 0;
690 
691 	if (!musb->controller->of_node) {
692 		dev_err(musb->controller, "Need DT for the DMA engine.\n");
693 		return NULL;
694 	}
695 
696 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
697 	if (!controller)
698 		goto kzalloc_fail;
699 
700 	hrtimer_init(&controller->early_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
701 	controller->early_tx.function = cppi41_recheck_tx_req;
702 	INIT_LIST_HEAD(&controller->early_tx_list);
703 	controller->musb = musb;
704 
705 	controller->controller.channel_alloc = cppi41_dma_channel_allocate;
706 	controller->controller.channel_release = cppi41_dma_channel_release;
707 	controller->controller.channel_program = cppi41_dma_channel_program;
708 	controller->controller.channel_abort = cppi41_dma_channel_abort;
709 	controller->controller.is_compatible = cppi41_is_compatible;
710 
711 	ret = cppi41_dma_controller_start(controller);
712 	if (ret)
713 		goto plat_get_fail;
714 	return &controller->controller;
715 
716 plat_get_fail:
717 	kfree(controller);
718 kzalloc_fail:
719 	if (ret == -EPROBE_DEFER)
720 		return ERR_PTR(ret);
721 	return NULL;
722 }
723