xref: /openbmc/linux/drivers/usb/musb/musb_cppi41.c (revision cfbb9be8)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/device.h>
3 #include <linux/dma-mapping.h>
4 #include <linux/dmaengine.h>
5 #include <linux/sizes.h>
6 #include <linux/platform_device.h>
7 #include <linux/of.h>
8 
9 #include "cppi_dma.h"
10 #include "musb_core.h"
11 #include "musb_trace.h"
12 
13 #define RNDIS_REG(x) (0x80 + ((x - 1) * 4))
14 
15 #define EP_MODE_AUTOREQ_NONE		0
16 #define EP_MODE_AUTOREQ_ALL_NEOP	1
17 #define EP_MODE_AUTOREQ_ALWAYS		3
18 
19 #define EP_MODE_DMA_TRANSPARENT		0
20 #define EP_MODE_DMA_RNDIS		1
21 #define EP_MODE_DMA_GEN_RNDIS		3
22 
23 #define USB_CTRL_TX_MODE	0x70
24 #define USB_CTRL_RX_MODE	0x74
25 #define USB_CTRL_AUTOREQ	0xd0
26 #define USB_TDOWN		0xd8
27 
28 #define MUSB_DMA_NUM_CHANNELS 15
29 
30 #define DA8XX_USB_MODE		0x10
31 #define DA8XX_USB_AUTOREQ	0x14
32 #define DA8XX_USB_TEARDOWN	0x1c
33 
34 #define DA8XX_DMA_NUM_CHANNELS 4
35 
36 struct cppi41_dma_controller {
37 	struct dma_controller controller;
38 	struct cppi41_dma_channel *rx_channel;
39 	struct cppi41_dma_channel *tx_channel;
40 	struct hrtimer early_tx;
41 	struct list_head early_tx_list;
42 	u32 rx_mode;
43 	u32 tx_mode;
44 	u32 auto_req;
45 
46 	u32 tdown_reg;
47 	u32 autoreq_reg;
48 
49 	void (*set_dma_mode)(struct cppi41_dma_channel *cppi41_channel,
50 			     unsigned int mode);
51 	u8 num_channels;
52 };
53 
54 static void save_rx_toggle(struct cppi41_dma_channel *cppi41_channel)
55 {
56 	u16 csr;
57 	u8 toggle;
58 
59 	if (cppi41_channel->is_tx)
60 		return;
61 	if (!is_host_active(cppi41_channel->controller->controller.musb))
62 		return;
63 
64 	csr = musb_readw(cppi41_channel->hw_ep->regs, MUSB_RXCSR);
65 	toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0;
66 
67 	cppi41_channel->usb_toggle = toggle;
68 }
69 
70 static void update_rx_toggle(struct cppi41_dma_channel *cppi41_channel)
71 {
72 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
73 	struct musb *musb = hw_ep->musb;
74 	u16 csr;
75 	u8 toggle;
76 
77 	if (cppi41_channel->is_tx)
78 		return;
79 	if (!is_host_active(musb))
80 		return;
81 
82 	musb_ep_select(musb->mregs, hw_ep->epnum);
83 	csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
84 	toggle = csr & MUSB_RXCSR_H_DATATOGGLE ? 1 : 0;
85 
86 	/*
87 	 * AM335x Advisory 1.0.13: Due to internal synchronisation error the
88 	 * data toggle may reset from DATA1 to DATA0 during receiving data from
89 	 * more than one endpoint.
90 	 */
91 	if (!toggle && toggle == cppi41_channel->usb_toggle) {
92 		csr |= MUSB_RXCSR_H_DATATOGGLE | MUSB_RXCSR_H_WR_DATATOGGLE;
93 		musb_writew(cppi41_channel->hw_ep->regs, MUSB_RXCSR, csr);
94 		musb_dbg(musb, "Restoring DATA1 toggle.");
95 	}
96 
97 	cppi41_channel->usb_toggle = toggle;
98 }
99 
100 static bool musb_is_tx_fifo_empty(struct musb_hw_ep *hw_ep)
101 {
102 	u8		epnum = hw_ep->epnum;
103 	struct musb	*musb = hw_ep->musb;
104 	void __iomem	*epio = musb->endpoints[epnum].regs;
105 	u16		csr;
106 
107 	musb_ep_select(musb->mregs, hw_ep->epnum);
108 	csr = musb_readw(epio, MUSB_TXCSR);
109 	if (csr & MUSB_TXCSR_TXPKTRDY)
110 		return false;
111 	return true;
112 }
113 
114 static void cppi41_dma_callback(void *private_data,
115 				const struct dmaengine_result *result);
116 
117 static void cppi41_trans_done(struct cppi41_dma_channel *cppi41_channel)
118 {
119 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
120 	struct musb *musb = hw_ep->musb;
121 	void __iomem *epio = hw_ep->regs;
122 	u16 csr;
123 
124 	if (!cppi41_channel->prog_len ||
125 	    (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)) {
126 
127 		/* done, complete */
128 		cppi41_channel->channel.actual_len =
129 			cppi41_channel->transferred;
130 		cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
131 		cppi41_channel->channel.rx_packet_done = true;
132 
133 		/*
134 		 * transmit ZLP using PIO mode for transfers which size is
135 		 * multiple of EP packet size.
136 		 */
137 		if (cppi41_channel->tx_zlp && (cppi41_channel->transferred %
138 					cppi41_channel->packet_sz) == 0) {
139 			musb_ep_select(musb->mregs, hw_ep->epnum);
140 			csr = MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY;
141 			musb_writew(epio, MUSB_TXCSR, csr);
142 		}
143 
144 		trace_musb_cppi41_done(cppi41_channel);
145 		musb_dma_completion(musb, hw_ep->epnum, cppi41_channel->is_tx);
146 	} else {
147 		/* next iteration, reload */
148 		struct dma_chan *dc = cppi41_channel->dc;
149 		struct dma_async_tx_descriptor *dma_desc;
150 		enum dma_transfer_direction direction;
151 		u32 remain_bytes;
152 
153 		cppi41_channel->buf_addr += cppi41_channel->packet_sz;
154 
155 		remain_bytes = cppi41_channel->total_len;
156 		remain_bytes -= cppi41_channel->transferred;
157 		remain_bytes = min(remain_bytes, cppi41_channel->packet_sz);
158 		cppi41_channel->prog_len = remain_bytes;
159 
160 		direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV
161 			: DMA_DEV_TO_MEM;
162 		dma_desc = dmaengine_prep_slave_single(dc,
163 				cppi41_channel->buf_addr,
164 				remain_bytes,
165 				direction,
166 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
167 		if (WARN_ON(!dma_desc))
168 			return;
169 
170 		dma_desc->callback_result = cppi41_dma_callback;
171 		dma_desc->callback_param = &cppi41_channel->channel;
172 		cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
173 		trace_musb_cppi41_cont(cppi41_channel);
174 		dma_async_issue_pending(dc);
175 
176 		if (!cppi41_channel->is_tx) {
177 			musb_ep_select(musb->mregs, hw_ep->epnum);
178 			csr = musb_readw(epio, MUSB_RXCSR);
179 			csr |= MUSB_RXCSR_H_REQPKT;
180 			musb_writew(epio, MUSB_RXCSR, csr);
181 		}
182 	}
183 }
184 
185 static enum hrtimer_restart cppi41_recheck_tx_req(struct hrtimer *timer)
186 {
187 	struct cppi41_dma_controller *controller;
188 	struct cppi41_dma_channel *cppi41_channel, *n;
189 	struct musb *musb;
190 	unsigned long flags;
191 	enum hrtimer_restart ret = HRTIMER_NORESTART;
192 
193 	controller = container_of(timer, struct cppi41_dma_controller,
194 			early_tx);
195 	musb = controller->controller.musb;
196 
197 	spin_lock_irqsave(&musb->lock, flags);
198 	list_for_each_entry_safe(cppi41_channel, n, &controller->early_tx_list,
199 			tx_check) {
200 		bool empty;
201 		struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
202 
203 		empty = musb_is_tx_fifo_empty(hw_ep);
204 		if (empty) {
205 			list_del_init(&cppi41_channel->tx_check);
206 			cppi41_trans_done(cppi41_channel);
207 		}
208 	}
209 
210 	if (!list_empty(&controller->early_tx_list) &&
211 	    !hrtimer_is_queued(&controller->early_tx)) {
212 		ret = HRTIMER_RESTART;
213 		hrtimer_forward_now(&controller->early_tx, 20 * NSEC_PER_USEC);
214 	}
215 
216 	spin_unlock_irqrestore(&musb->lock, flags);
217 	return ret;
218 }
219 
220 static void cppi41_dma_callback(void *private_data,
221 				const struct dmaengine_result *result)
222 {
223 	struct dma_channel *channel = private_data;
224 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
225 	struct musb_hw_ep *hw_ep = cppi41_channel->hw_ep;
226 	struct cppi41_dma_controller *controller;
227 	struct musb *musb = hw_ep->musb;
228 	unsigned long flags;
229 	struct dma_tx_state txstate;
230 	u32 transferred;
231 	int is_hs = 0;
232 	bool empty;
233 
234 	controller = cppi41_channel->controller;
235 	if (controller->controller.dma_callback)
236 		controller->controller.dma_callback(&controller->controller);
237 
238 	if (result->result == DMA_TRANS_ABORTED)
239 		return;
240 
241 	spin_lock_irqsave(&musb->lock, flags);
242 
243 	dmaengine_tx_status(cppi41_channel->dc, cppi41_channel->cookie,
244 			&txstate);
245 	transferred = cppi41_channel->prog_len - txstate.residue;
246 	cppi41_channel->transferred += transferred;
247 
248 	trace_musb_cppi41_gb(cppi41_channel);
249 	update_rx_toggle(cppi41_channel);
250 
251 	if (cppi41_channel->transferred == cppi41_channel->total_len ||
252 			transferred < cppi41_channel->packet_sz)
253 		cppi41_channel->prog_len = 0;
254 
255 	if (cppi41_channel->is_tx) {
256 		u8 type;
257 
258 		if (is_host_active(musb))
259 			type = hw_ep->out_qh->type;
260 		else
261 			type = hw_ep->ep_in.type;
262 
263 		if (type == USB_ENDPOINT_XFER_ISOC)
264 			/*
265 			 * Don't use the early-TX-interrupt workaround below
266 			 * for Isoch transfter. Since Isoch are periodic
267 			 * transfer, by the time the next transfer is
268 			 * scheduled, the current one should be done already.
269 			 *
270 			 * This avoids audio playback underrun issue.
271 			 */
272 			empty = true;
273 		else
274 			empty = musb_is_tx_fifo_empty(hw_ep);
275 	}
276 
277 	if (!cppi41_channel->is_tx || empty) {
278 		cppi41_trans_done(cppi41_channel);
279 		goto out;
280 	}
281 
282 	/*
283 	 * On AM335x it has been observed that the TX interrupt fires
284 	 * too early that means the TXFIFO is not yet empty but the DMA
285 	 * engine says that it is done with the transfer. We don't
286 	 * receive a FIFO empty interrupt so the only thing we can do is
287 	 * to poll for the bit. On HS it usually takes 2us, on FS around
288 	 * 110us - 150us depending on the transfer size.
289 	 * We spin on HS (no longer than than 25us and setup a timer on
290 	 * FS to check for the bit and complete the transfer.
291 	 */
292 	if (is_host_active(musb)) {
293 		if (musb->port1_status & USB_PORT_STAT_HIGH_SPEED)
294 			is_hs = 1;
295 	} else {
296 		if (musb->g.speed == USB_SPEED_HIGH)
297 			is_hs = 1;
298 	}
299 	if (is_hs) {
300 		unsigned wait = 25;
301 
302 		do {
303 			empty = musb_is_tx_fifo_empty(hw_ep);
304 			if (empty) {
305 				cppi41_trans_done(cppi41_channel);
306 				goto out;
307 			}
308 			wait--;
309 			if (!wait)
310 				break;
311 			cpu_relax();
312 		} while (1);
313 	}
314 	list_add_tail(&cppi41_channel->tx_check,
315 			&controller->early_tx_list);
316 	if (!hrtimer_is_queued(&controller->early_tx)) {
317 		unsigned long usecs = cppi41_channel->total_len / 10;
318 
319 		hrtimer_start_range_ns(&controller->early_tx,
320 				       usecs * NSEC_PER_USEC,
321 				       20 * NSEC_PER_USEC,
322 				       HRTIMER_MODE_REL);
323 	}
324 
325 out:
326 	spin_unlock_irqrestore(&musb->lock, flags);
327 }
328 
329 static u32 update_ep_mode(unsigned ep, unsigned mode, u32 old)
330 {
331 	unsigned shift;
332 
333 	shift = (ep - 1) * 2;
334 	old &= ~(3 << shift);
335 	old |= mode << shift;
336 	return old;
337 }
338 
339 static void cppi41_set_dma_mode(struct cppi41_dma_channel *cppi41_channel,
340 		unsigned mode)
341 {
342 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
343 	struct musb *musb = controller->controller.musb;
344 	u32 port;
345 	u32 new_mode;
346 	u32 old_mode;
347 
348 	if (cppi41_channel->is_tx)
349 		old_mode = controller->tx_mode;
350 	else
351 		old_mode = controller->rx_mode;
352 	port = cppi41_channel->port_num;
353 	new_mode = update_ep_mode(port, mode, old_mode);
354 
355 	if (new_mode == old_mode)
356 		return;
357 	if (cppi41_channel->is_tx) {
358 		controller->tx_mode = new_mode;
359 		musb_writel(musb->ctrl_base, USB_CTRL_TX_MODE, new_mode);
360 	} else {
361 		controller->rx_mode = new_mode;
362 		musb_writel(musb->ctrl_base, USB_CTRL_RX_MODE, new_mode);
363 	}
364 }
365 
366 static void da8xx_set_dma_mode(struct cppi41_dma_channel *cppi41_channel,
367 		unsigned int mode)
368 {
369 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
370 	struct musb *musb = controller->controller.musb;
371 	unsigned int shift;
372 	u32 port;
373 	u32 new_mode;
374 	u32 old_mode;
375 
376 	old_mode = controller->tx_mode;
377 	port = cppi41_channel->port_num;
378 
379 	shift = (port - 1) * 4;
380 	if (!cppi41_channel->is_tx)
381 		shift += 16;
382 	new_mode = old_mode & ~(3 << shift);
383 	new_mode |= mode << shift;
384 
385 	if (new_mode == old_mode)
386 		return;
387 	controller->tx_mode = new_mode;
388 	musb_writel(musb->ctrl_base, DA8XX_USB_MODE, new_mode);
389 }
390 
391 
392 static void cppi41_set_autoreq_mode(struct cppi41_dma_channel *cppi41_channel,
393 		unsigned mode)
394 {
395 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
396 	u32 port;
397 	u32 new_mode;
398 	u32 old_mode;
399 
400 	old_mode = controller->auto_req;
401 	port = cppi41_channel->port_num;
402 	new_mode = update_ep_mode(port, mode, old_mode);
403 
404 	if (new_mode == old_mode)
405 		return;
406 	controller->auto_req = new_mode;
407 	musb_writel(controller->controller.musb->ctrl_base,
408 		    controller->autoreq_reg, new_mode);
409 }
410 
411 static bool cppi41_configure_channel(struct dma_channel *channel,
412 				u16 packet_sz, u8 mode,
413 				dma_addr_t dma_addr, u32 len)
414 {
415 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
416 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
417 	struct dma_chan *dc = cppi41_channel->dc;
418 	struct dma_async_tx_descriptor *dma_desc;
419 	enum dma_transfer_direction direction;
420 	struct musb *musb = cppi41_channel->controller->controller.musb;
421 	unsigned use_gen_rndis = 0;
422 
423 	cppi41_channel->buf_addr = dma_addr;
424 	cppi41_channel->total_len = len;
425 	cppi41_channel->transferred = 0;
426 	cppi41_channel->packet_sz = packet_sz;
427 	cppi41_channel->tx_zlp = (cppi41_channel->is_tx && mode) ? 1 : 0;
428 
429 	/*
430 	 * Due to AM335x' Advisory 1.0.13 we are not allowed to transfer more
431 	 * than max packet size at a time.
432 	 */
433 	if (cppi41_channel->is_tx)
434 		use_gen_rndis = 1;
435 
436 	if (use_gen_rndis) {
437 		/* RNDIS mode */
438 		if (len > packet_sz) {
439 			musb_writel(musb->ctrl_base,
440 				RNDIS_REG(cppi41_channel->port_num), len);
441 			/* gen rndis */
442 			controller->set_dma_mode(cppi41_channel,
443 					EP_MODE_DMA_GEN_RNDIS);
444 
445 			/* auto req */
446 			cppi41_set_autoreq_mode(cppi41_channel,
447 					EP_MODE_AUTOREQ_ALL_NEOP);
448 		} else {
449 			musb_writel(musb->ctrl_base,
450 					RNDIS_REG(cppi41_channel->port_num), 0);
451 			controller->set_dma_mode(cppi41_channel,
452 					EP_MODE_DMA_TRANSPARENT);
453 			cppi41_set_autoreq_mode(cppi41_channel,
454 					EP_MODE_AUTOREQ_NONE);
455 		}
456 	} else {
457 		/* fallback mode */
458 		controller->set_dma_mode(cppi41_channel,
459 				EP_MODE_DMA_TRANSPARENT);
460 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);
461 		len = min_t(u32, packet_sz, len);
462 	}
463 	cppi41_channel->prog_len = len;
464 	direction = cppi41_channel->is_tx ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
465 	dma_desc = dmaengine_prep_slave_single(dc, dma_addr, len, direction,
466 			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
467 	if (!dma_desc)
468 		return false;
469 
470 	dma_desc->callback_result = cppi41_dma_callback;
471 	dma_desc->callback_param = channel;
472 	cppi41_channel->cookie = dma_desc->tx_submit(dma_desc);
473 	cppi41_channel->channel.rx_packet_done = false;
474 
475 	trace_musb_cppi41_config(cppi41_channel);
476 
477 	save_rx_toggle(cppi41_channel);
478 	dma_async_issue_pending(dc);
479 	return true;
480 }
481 
482 static struct dma_channel *cppi41_dma_channel_allocate(struct dma_controller *c,
483 				struct musb_hw_ep *hw_ep, u8 is_tx)
484 {
485 	struct cppi41_dma_controller *controller = container_of(c,
486 			struct cppi41_dma_controller, controller);
487 	struct cppi41_dma_channel *cppi41_channel = NULL;
488 	u8 ch_num = hw_ep->epnum - 1;
489 
490 	if (ch_num >= controller->num_channels)
491 		return NULL;
492 
493 	if (is_tx)
494 		cppi41_channel = &controller->tx_channel[ch_num];
495 	else
496 		cppi41_channel = &controller->rx_channel[ch_num];
497 
498 	if (!cppi41_channel->dc)
499 		return NULL;
500 
501 	if (cppi41_channel->is_allocated)
502 		return NULL;
503 
504 	cppi41_channel->hw_ep = hw_ep;
505 	cppi41_channel->is_allocated = 1;
506 
507 	trace_musb_cppi41_alloc(cppi41_channel);
508 	return &cppi41_channel->channel;
509 }
510 
511 static void cppi41_dma_channel_release(struct dma_channel *channel)
512 {
513 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
514 
515 	trace_musb_cppi41_free(cppi41_channel);
516 	if (cppi41_channel->is_allocated) {
517 		cppi41_channel->is_allocated = 0;
518 		channel->status = MUSB_DMA_STATUS_FREE;
519 		channel->actual_len = 0;
520 	}
521 }
522 
523 static int cppi41_dma_channel_program(struct dma_channel *channel,
524 				u16 packet_sz, u8 mode,
525 				dma_addr_t dma_addr, u32 len)
526 {
527 	int ret;
528 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
529 	int hb_mult = 0;
530 
531 	BUG_ON(channel->status == MUSB_DMA_STATUS_UNKNOWN ||
532 		channel->status == MUSB_DMA_STATUS_BUSY);
533 
534 	if (is_host_active(cppi41_channel->controller->controller.musb)) {
535 		if (cppi41_channel->is_tx)
536 			hb_mult = cppi41_channel->hw_ep->out_qh->hb_mult;
537 		else
538 			hb_mult = cppi41_channel->hw_ep->in_qh->hb_mult;
539 	}
540 
541 	channel->status = MUSB_DMA_STATUS_BUSY;
542 	channel->actual_len = 0;
543 
544 	if (hb_mult)
545 		packet_sz = hb_mult * (packet_sz & 0x7FF);
546 
547 	ret = cppi41_configure_channel(channel, packet_sz, mode, dma_addr, len);
548 	if (!ret)
549 		channel->status = MUSB_DMA_STATUS_FREE;
550 
551 	return ret;
552 }
553 
554 static int cppi41_is_compatible(struct dma_channel *channel, u16 maxpacket,
555 		void *buf, u32 length)
556 {
557 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
558 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
559 	struct musb *musb = controller->controller.musb;
560 
561 	if (is_host_active(musb)) {
562 		WARN_ON(1);
563 		return 1;
564 	}
565 	if (cppi41_channel->hw_ep->ep_in.type != USB_ENDPOINT_XFER_BULK)
566 		return 0;
567 	if (cppi41_channel->is_tx)
568 		return 1;
569 	/* AM335x Advisory 1.0.13. No workaround for device RX mode */
570 	return 0;
571 }
572 
573 static int cppi41_dma_channel_abort(struct dma_channel *channel)
574 {
575 	struct cppi41_dma_channel *cppi41_channel = channel->private_data;
576 	struct cppi41_dma_controller *controller = cppi41_channel->controller;
577 	struct musb *musb = controller->controller.musb;
578 	void __iomem *epio = cppi41_channel->hw_ep->regs;
579 	int tdbit;
580 	int ret;
581 	unsigned is_tx;
582 	u16 csr;
583 
584 	is_tx = cppi41_channel->is_tx;
585 	trace_musb_cppi41_abort(cppi41_channel);
586 
587 	if (cppi41_channel->channel.status == MUSB_DMA_STATUS_FREE)
588 		return 0;
589 
590 	list_del_init(&cppi41_channel->tx_check);
591 	if (is_tx) {
592 		csr = musb_readw(epio, MUSB_TXCSR);
593 		csr &= ~MUSB_TXCSR_DMAENAB;
594 		musb_writew(epio, MUSB_TXCSR, csr);
595 	} else {
596 		cppi41_set_autoreq_mode(cppi41_channel, EP_MODE_AUTOREQ_NONE);
597 
598 		/* delay to drain to cppi dma pipeline for isoch */
599 		udelay(250);
600 
601 		csr = musb_readw(epio, MUSB_RXCSR);
602 		csr &= ~(MUSB_RXCSR_H_REQPKT | MUSB_RXCSR_DMAENAB);
603 		musb_writew(epio, MUSB_RXCSR, csr);
604 
605 		/* wait to drain cppi dma pipe line */
606 		udelay(50);
607 
608 		csr = musb_readw(epio, MUSB_RXCSR);
609 		if (csr & MUSB_RXCSR_RXPKTRDY) {
610 			csr |= MUSB_RXCSR_FLUSHFIFO;
611 			musb_writew(epio, MUSB_RXCSR, csr);
612 			musb_writew(epio, MUSB_RXCSR, csr);
613 		}
614 	}
615 
616 	/* DA8xx Advisory 2.3.27: wait 250 ms before to start the teardown */
617 	if (musb->io.quirks & MUSB_DA8XX)
618 		mdelay(250);
619 
620 	tdbit = 1 << cppi41_channel->port_num;
621 	if (is_tx)
622 		tdbit <<= 16;
623 
624 	do {
625 		if (is_tx)
626 			musb_writel(musb->ctrl_base, controller->tdown_reg,
627 				    tdbit);
628 		ret = dmaengine_terminate_all(cppi41_channel->dc);
629 	} while (ret == -EAGAIN);
630 
631 	if (is_tx) {
632 		musb_writel(musb->ctrl_base, controller->tdown_reg, tdbit);
633 
634 		csr = musb_readw(epio, MUSB_TXCSR);
635 		if (csr & MUSB_TXCSR_TXPKTRDY) {
636 			csr |= MUSB_TXCSR_FLUSHFIFO;
637 			musb_writew(epio, MUSB_TXCSR, csr);
638 		}
639 	}
640 
641 	cppi41_channel->channel.status = MUSB_DMA_STATUS_FREE;
642 	return 0;
643 }
644 
645 static void cppi41_release_all_dma_chans(struct cppi41_dma_controller *ctrl)
646 {
647 	struct dma_chan *dc;
648 	int i;
649 
650 	for (i = 0; i < ctrl->num_channels; i++) {
651 		dc = ctrl->tx_channel[i].dc;
652 		if (dc)
653 			dma_release_channel(dc);
654 		dc = ctrl->rx_channel[i].dc;
655 		if (dc)
656 			dma_release_channel(dc);
657 	}
658 }
659 
660 static void cppi41_dma_controller_stop(struct cppi41_dma_controller *controller)
661 {
662 	cppi41_release_all_dma_chans(controller);
663 }
664 
665 static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
666 {
667 	struct musb *musb = controller->controller.musb;
668 	struct device *dev = musb->controller;
669 	struct device_node *np = dev->parent->of_node;
670 	struct cppi41_dma_channel *cppi41_channel;
671 	int count;
672 	int i;
673 	int ret;
674 
675 	count = of_property_count_strings(np, "dma-names");
676 	if (count < 0)
677 		return count;
678 
679 	for (i = 0; i < count; i++) {
680 		struct dma_chan *dc;
681 		struct dma_channel *musb_dma;
682 		const char *str;
683 		unsigned is_tx;
684 		unsigned int port;
685 
686 		ret = of_property_read_string_index(np, "dma-names", i, &str);
687 		if (ret)
688 			goto err;
689 		if (strstarts(str, "tx"))
690 			is_tx = 1;
691 		else if (strstarts(str, "rx"))
692 			is_tx = 0;
693 		else {
694 			dev_err(dev, "Wrong dmatype %s\n", str);
695 			goto err;
696 		}
697 		ret = kstrtouint(str + 2, 0, &port);
698 		if (ret)
699 			goto err;
700 
701 		ret = -EINVAL;
702 		if (port > controller->num_channels || !port)
703 			goto err;
704 		if (is_tx)
705 			cppi41_channel = &controller->tx_channel[port - 1];
706 		else
707 			cppi41_channel = &controller->rx_channel[port - 1];
708 
709 		cppi41_channel->controller = controller;
710 		cppi41_channel->port_num = port;
711 		cppi41_channel->is_tx = is_tx;
712 		INIT_LIST_HEAD(&cppi41_channel->tx_check);
713 
714 		musb_dma = &cppi41_channel->channel;
715 		musb_dma->private_data = cppi41_channel;
716 		musb_dma->status = MUSB_DMA_STATUS_FREE;
717 		musb_dma->max_len = SZ_4M;
718 
719 		dc = dma_request_chan(dev->parent, str);
720 		if (IS_ERR(dc)) {
721 			ret = PTR_ERR(dc);
722 			if (ret != -EPROBE_DEFER)
723 				dev_err(dev, "Failed to request %s: %d.\n",
724 					str, ret);
725 			goto err;
726 		}
727 
728 		cppi41_channel->dc = dc;
729 	}
730 	return 0;
731 err:
732 	cppi41_release_all_dma_chans(controller);
733 	return ret;
734 }
735 
736 void cppi41_dma_controller_destroy(struct dma_controller *c)
737 {
738 	struct cppi41_dma_controller *controller = container_of(c,
739 			struct cppi41_dma_controller, controller);
740 
741 	hrtimer_cancel(&controller->early_tx);
742 	cppi41_dma_controller_stop(controller);
743 	kfree(controller->rx_channel);
744 	kfree(controller->tx_channel);
745 	kfree(controller);
746 }
747 EXPORT_SYMBOL_GPL(cppi41_dma_controller_destroy);
748 
749 struct dma_controller *
750 cppi41_dma_controller_create(struct musb *musb, void __iomem *base)
751 {
752 	struct cppi41_dma_controller *controller;
753 	int channel_size;
754 	int ret = 0;
755 
756 	if (!musb->controller->parent->of_node) {
757 		dev_err(musb->controller, "Need DT for the DMA engine.\n");
758 		return NULL;
759 	}
760 
761 	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
762 	if (!controller)
763 		goto kzalloc_fail;
764 
765 	hrtimer_init(&controller->early_tx, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
766 	controller->early_tx.function = cppi41_recheck_tx_req;
767 	INIT_LIST_HEAD(&controller->early_tx_list);
768 
769 	controller->controller.channel_alloc = cppi41_dma_channel_allocate;
770 	controller->controller.channel_release = cppi41_dma_channel_release;
771 	controller->controller.channel_program = cppi41_dma_channel_program;
772 	controller->controller.channel_abort = cppi41_dma_channel_abort;
773 	controller->controller.is_compatible = cppi41_is_compatible;
774 	controller->controller.musb = musb;
775 
776 	if (musb->io.quirks & MUSB_DA8XX) {
777 		controller->tdown_reg = DA8XX_USB_TEARDOWN;
778 		controller->autoreq_reg = DA8XX_USB_AUTOREQ;
779 		controller->set_dma_mode = da8xx_set_dma_mode;
780 		controller->num_channels = DA8XX_DMA_NUM_CHANNELS;
781 	} else {
782 		controller->tdown_reg = USB_TDOWN;
783 		controller->autoreq_reg = USB_CTRL_AUTOREQ;
784 		controller->set_dma_mode = cppi41_set_dma_mode;
785 		controller->num_channels = MUSB_DMA_NUM_CHANNELS;
786 	}
787 
788 	channel_size = controller->num_channels *
789 			sizeof(struct cppi41_dma_channel);
790 	controller->rx_channel = kzalloc(channel_size, GFP_KERNEL);
791 	if (!controller->rx_channel)
792 		goto rx_channel_alloc_fail;
793 	controller->tx_channel = kzalloc(channel_size, GFP_KERNEL);
794 	if (!controller->tx_channel)
795 		goto tx_channel_alloc_fail;
796 
797 	ret = cppi41_dma_controller_start(controller);
798 	if (ret)
799 		goto plat_get_fail;
800 	return &controller->controller;
801 
802 plat_get_fail:
803 	kfree(controller->tx_channel);
804 tx_channel_alloc_fail:
805 	kfree(controller->rx_channel);
806 rx_channel_alloc_fail:
807 	kfree(controller);
808 kzalloc_fail:
809 	if (ret == -EPROBE_DEFER)
810 		return ERR_PTR(ret);
811 	return NULL;
812 }
813 EXPORT_SYMBOL_GPL(cppi41_dma_controller_create);
814