xref: /openbmc/linux/drivers/usb/dwc3/gadget.c (revision dc6a81c3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * gadget.c - DesignWare USB3 DRD Controller Gadget Framework Link
4  *
5  * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
6  *
7  * Authors: Felipe Balbi <balbi@ti.com>,
8  *	    Sebastian Andrzej Siewior <bigeasy@linutronix.de>
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/delay.h>
13 #include <linux/slab.h>
14 #include <linux/spinlock.h>
15 #include <linux/platform_device.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/interrupt.h>
18 #include <linux/io.h>
19 #include <linux/list.h>
20 #include <linux/dma-mapping.h>
21 
22 #include <linux/usb/ch9.h>
23 #include <linux/usb/gadget.h>
24 
25 #include "debug.h"
26 #include "core.h"
27 #include "gadget.h"
28 #include "io.h"
29 
30 #define DWC3_ALIGN_FRAME(d, n)	(((d)->frame_number + ((d)->interval * (n))) \
31 					& ~((d)->interval - 1))
32 
33 /**
34  * dwc3_gadget_set_test_mode - enables usb2 test modes
35  * @dwc: pointer to our context structure
36  * @mode: the mode to set (J, K SE0 NAK, Force Enable)
37  *
38  * Caller should take care of locking. This function will return 0 on
39  * success or -EINVAL if wrong Test Selector is passed.
40  */
41 int dwc3_gadget_set_test_mode(struct dwc3 *dwc, int mode)
42 {
43 	u32		reg;
44 
45 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
46 	reg &= ~DWC3_DCTL_TSTCTRL_MASK;
47 
48 	switch (mode) {
49 	case TEST_J:
50 	case TEST_K:
51 	case TEST_SE0_NAK:
52 	case TEST_PACKET:
53 	case TEST_FORCE_EN:
54 		reg |= mode << 1;
55 		break;
56 	default:
57 		return -EINVAL;
58 	}
59 
60 	dwc3_gadget_dctl_write_safe(dwc, reg);
61 
62 	return 0;
63 }
64 
65 /**
66  * dwc3_gadget_get_link_state - gets current state of usb link
67  * @dwc: pointer to our context structure
68  *
69  * Caller should take care of locking. This function will
70  * return the link state on success (>= 0) or -ETIMEDOUT.
71  */
72 int dwc3_gadget_get_link_state(struct dwc3 *dwc)
73 {
74 	u32		reg;
75 
76 	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
77 
78 	return DWC3_DSTS_USBLNKST(reg);
79 }
80 
81 /**
82  * dwc3_gadget_set_link_state - sets usb link to a particular state
83  * @dwc: pointer to our context structure
84  * @state: the state to put link into
85  *
86  * Caller should take care of locking. This function will
87  * return 0 on success or -ETIMEDOUT.
88  */
89 int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum dwc3_link_state state)
90 {
91 	int		retries = 10000;
92 	u32		reg;
93 
94 	/*
95 	 * Wait until device controller is ready. Only applies to 1.94a and
96 	 * later RTL.
97 	 */
98 	if (dwc->revision >= DWC3_REVISION_194A) {
99 		while (--retries) {
100 			reg = dwc3_readl(dwc->regs, DWC3_DSTS);
101 			if (reg & DWC3_DSTS_DCNRD)
102 				udelay(5);
103 			else
104 				break;
105 		}
106 
107 		if (retries <= 0)
108 			return -ETIMEDOUT;
109 	}
110 
111 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
112 	reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
113 
114 	/* set no action before sending new link state change */
115 	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
116 
117 	/* set requested state */
118 	reg |= DWC3_DCTL_ULSTCHNGREQ(state);
119 	dwc3_writel(dwc->regs, DWC3_DCTL, reg);
120 
121 	/*
122 	 * The following code is racy when called from dwc3_gadget_wakeup,
123 	 * and is not needed, at least on newer versions
124 	 */
125 	if (dwc->revision >= DWC3_REVISION_194A)
126 		return 0;
127 
128 	/* wait for a change in DSTS */
129 	retries = 10000;
130 	while (--retries) {
131 		reg = dwc3_readl(dwc->regs, DWC3_DSTS);
132 
133 		if (DWC3_DSTS_USBLNKST(reg) == state)
134 			return 0;
135 
136 		udelay(5);
137 	}
138 
139 	return -ETIMEDOUT;
140 }
141 
142 /**
143  * dwc3_ep_inc_trb - increment a trb index.
144  * @index: Pointer to the TRB index to increment.
145  *
146  * The index should never point to the link TRB. After incrementing,
147  * if it is point to the link TRB, wrap around to the beginning. The
148  * link TRB is always at the last TRB entry.
149  */
150 static void dwc3_ep_inc_trb(u8 *index)
151 {
152 	(*index)++;
153 	if (*index == (DWC3_TRB_NUM - 1))
154 		*index = 0;
155 }
156 
157 /**
158  * dwc3_ep_inc_enq - increment endpoint's enqueue pointer
159  * @dep: The endpoint whose enqueue pointer we're incrementing
160  */
161 static void dwc3_ep_inc_enq(struct dwc3_ep *dep)
162 {
163 	dwc3_ep_inc_trb(&dep->trb_enqueue);
164 }
165 
166 /**
167  * dwc3_ep_inc_deq - increment endpoint's dequeue pointer
168  * @dep: The endpoint whose enqueue pointer we're incrementing
169  */
170 static void dwc3_ep_inc_deq(struct dwc3_ep *dep)
171 {
172 	dwc3_ep_inc_trb(&dep->trb_dequeue);
173 }
174 
175 static void dwc3_gadget_del_and_unmap_request(struct dwc3_ep *dep,
176 		struct dwc3_request *req, int status)
177 {
178 	struct dwc3			*dwc = dep->dwc;
179 
180 	list_del(&req->list);
181 	req->remaining = 0;
182 	req->needs_extra_trb = false;
183 
184 	if (req->request.status == -EINPROGRESS)
185 		req->request.status = status;
186 
187 	if (req->trb)
188 		usb_gadget_unmap_request_by_dev(dwc->sysdev,
189 				&req->request, req->direction);
190 
191 	req->trb = NULL;
192 	trace_dwc3_gadget_giveback(req);
193 
194 	if (dep->number > 1)
195 		pm_runtime_put(dwc->dev);
196 }
197 
198 /**
199  * dwc3_gadget_giveback - call struct usb_request's ->complete callback
200  * @dep: The endpoint to whom the request belongs to
201  * @req: The request we're giving back
202  * @status: completion code for the request
203  *
204  * Must be called with controller's lock held and interrupts disabled. This
205  * function will unmap @req and call its ->complete() callback to notify upper
206  * layers that it has completed.
207  */
208 void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
209 		int status)
210 {
211 	struct dwc3			*dwc = dep->dwc;
212 
213 	dwc3_gadget_del_and_unmap_request(dep, req, status);
214 	req->status = DWC3_REQUEST_STATUS_COMPLETED;
215 
216 	spin_unlock(&dwc->lock);
217 	usb_gadget_giveback_request(&dep->endpoint, &req->request);
218 	spin_lock(&dwc->lock);
219 }
220 
221 /**
222  * dwc3_send_gadget_generic_command - issue a generic command for the controller
223  * @dwc: pointer to the controller context
224  * @cmd: the command to be issued
225  * @param: command parameter
226  *
227  * Caller should take care of locking. Issue @cmd with a given @param to @dwc
228  * and wait for its completion.
229  */
230 int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)
231 {
232 	u32		timeout = 500;
233 	int		status = 0;
234 	int		ret = 0;
235 	u32		reg;
236 
237 	dwc3_writel(dwc->regs, DWC3_DGCMDPAR, param);
238 	dwc3_writel(dwc->regs, DWC3_DGCMD, cmd | DWC3_DGCMD_CMDACT);
239 
240 	do {
241 		reg = dwc3_readl(dwc->regs, DWC3_DGCMD);
242 		if (!(reg & DWC3_DGCMD_CMDACT)) {
243 			status = DWC3_DGCMD_STATUS(reg);
244 			if (status)
245 				ret = -EINVAL;
246 			break;
247 		}
248 	} while (--timeout);
249 
250 	if (!timeout) {
251 		ret = -ETIMEDOUT;
252 		status = -ETIMEDOUT;
253 	}
254 
255 	trace_dwc3_gadget_generic_cmd(cmd, param, status);
256 
257 	return ret;
258 }
259 
260 static int __dwc3_gadget_wakeup(struct dwc3 *dwc);
261 
262 /**
263  * dwc3_send_gadget_ep_cmd - issue an endpoint command
264  * @dep: the endpoint to which the command is going to be issued
265  * @cmd: the command to be issued
266  * @params: parameters to the command
267  *
268  * Caller should handle locking. This function will issue @cmd with given
269  * @params to @dep and wait for its completion.
270  */
271 int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned cmd,
272 		struct dwc3_gadget_ep_cmd_params *params)
273 {
274 	const struct usb_endpoint_descriptor *desc = dep->endpoint.desc;
275 	struct dwc3		*dwc = dep->dwc;
276 	u32			timeout = 1000;
277 	u32			saved_config = 0;
278 	u32			reg;
279 
280 	int			cmd_status = 0;
281 	int			ret = -EINVAL;
282 
283 	/*
284 	 * When operating in USB 2.0 speeds (HS/FS), if GUSB2PHYCFG.ENBLSLPM or
285 	 * GUSB2PHYCFG.SUSPHY is set, it must be cleared before issuing an
286 	 * endpoint command.
287 	 *
288 	 * Save and clear both GUSB2PHYCFG.ENBLSLPM and GUSB2PHYCFG.SUSPHY
289 	 * settings. Restore them after the command is completed.
290 	 *
291 	 * DWC_usb3 3.30a and DWC_usb31 1.90a programming guide section 3.2.2
292 	 */
293 	if (dwc->gadget.speed <= USB_SPEED_HIGH) {
294 		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
295 		if (unlikely(reg & DWC3_GUSB2PHYCFG_SUSPHY)) {
296 			saved_config |= DWC3_GUSB2PHYCFG_SUSPHY;
297 			reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
298 		}
299 
300 		if (reg & DWC3_GUSB2PHYCFG_ENBLSLPM) {
301 			saved_config |= DWC3_GUSB2PHYCFG_ENBLSLPM;
302 			reg &= ~DWC3_GUSB2PHYCFG_ENBLSLPM;
303 		}
304 
305 		if (saved_config)
306 			dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
307 	}
308 
309 	if (DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_STARTTRANSFER) {
310 		int		needs_wakeup;
311 
312 		needs_wakeup = (dwc->link_state == DWC3_LINK_STATE_U1 ||
313 				dwc->link_state == DWC3_LINK_STATE_U2 ||
314 				dwc->link_state == DWC3_LINK_STATE_U3);
315 
316 		if (unlikely(needs_wakeup)) {
317 			ret = __dwc3_gadget_wakeup(dwc);
318 			dev_WARN_ONCE(dwc->dev, ret, "wakeup failed --> %d\n",
319 					ret);
320 		}
321 	}
322 
323 	dwc3_writel(dep->regs, DWC3_DEPCMDPAR0, params->param0);
324 	dwc3_writel(dep->regs, DWC3_DEPCMDPAR1, params->param1);
325 	dwc3_writel(dep->regs, DWC3_DEPCMDPAR2, params->param2);
326 
327 	/*
328 	 * Synopsys Databook 2.60a states in section 6.3.2.5.6 of that if we're
329 	 * not relying on XferNotReady, we can make use of a special "No
330 	 * Response Update Transfer" command where we should clear both CmdAct
331 	 * and CmdIOC bits.
332 	 *
333 	 * With this, we don't need to wait for command completion and can
334 	 * straight away issue further commands to the endpoint.
335 	 *
336 	 * NOTICE: We're making an assumption that control endpoints will never
337 	 * make use of Update Transfer command. This is a safe assumption
338 	 * because we can never have more than one request at a time with
339 	 * Control Endpoints. If anybody changes that assumption, this chunk
340 	 * needs to be updated accordingly.
341 	 */
342 	if (DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_UPDATETRANSFER &&
343 			!usb_endpoint_xfer_isoc(desc))
344 		cmd &= ~(DWC3_DEPCMD_CMDIOC | DWC3_DEPCMD_CMDACT);
345 	else
346 		cmd |= DWC3_DEPCMD_CMDACT;
347 
348 	dwc3_writel(dep->regs, DWC3_DEPCMD, cmd);
349 	do {
350 		reg = dwc3_readl(dep->regs, DWC3_DEPCMD);
351 		if (!(reg & DWC3_DEPCMD_CMDACT)) {
352 			cmd_status = DWC3_DEPCMD_STATUS(reg);
353 
354 			switch (cmd_status) {
355 			case 0:
356 				ret = 0;
357 				break;
358 			case DEPEVT_TRANSFER_NO_RESOURCE:
359 				ret = -EINVAL;
360 				break;
361 			case DEPEVT_TRANSFER_BUS_EXPIRY:
362 				/*
363 				 * SW issues START TRANSFER command to
364 				 * isochronous ep with future frame interval. If
365 				 * future interval time has already passed when
366 				 * core receives the command, it will respond
367 				 * with an error status of 'Bus Expiry'.
368 				 *
369 				 * Instead of always returning -EINVAL, let's
370 				 * give a hint to the gadget driver that this is
371 				 * the case by returning -EAGAIN.
372 				 */
373 				ret = -EAGAIN;
374 				break;
375 			default:
376 				dev_WARN(dwc->dev, "UNKNOWN cmd status\n");
377 			}
378 
379 			break;
380 		}
381 	} while (--timeout);
382 
383 	if (timeout == 0) {
384 		ret = -ETIMEDOUT;
385 		cmd_status = -ETIMEDOUT;
386 	}
387 
388 	trace_dwc3_gadget_ep_cmd(dep, cmd, params, cmd_status);
389 
390 	if (ret == 0 && DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_STARTTRANSFER) {
391 		dep->flags |= DWC3_EP_TRANSFER_STARTED;
392 		dwc3_gadget_ep_get_transfer_index(dep);
393 	}
394 
395 	if (saved_config) {
396 		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
397 		reg |= saved_config;
398 		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
399 	}
400 
401 	return ret;
402 }
403 
404 static int dwc3_send_clear_stall_ep_cmd(struct dwc3_ep *dep)
405 {
406 	struct dwc3 *dwc = dep->dwc;
407 	struct dwc3_gadget_ep_cmd_params params;
408 	u32 cmd = DWC3_DEPCMD_CLEARSTALL;
409 
410 	/*
411 	 * As of core revision 2.60a the recommended programming model
412 	 * is to set the ClearPendIN bit when issuing a Clear Stall EP
413 	 * command for IN endpoints. This is to prevent an issue where
414 	 * some (non-compliant) hosts may not send ACK TPs for pending
415 	 * IN transfers due to a mishandled error condition. Synopsys
416 	 * STAR 9000614252.
417 	 */
418 	if (dep->direction && (dwc->revision >= DWC3_REVISION_260A) &&
419 	    (dwc->gadget.speed >= USB_SPEED_SUPER))
420 		cmd |= DWC3_DEPCMD_CLEARPENDIN;
421 
422 	memset(&params, 0, sizeof(params));
423 
424 	return dwc3_send_gadget_ep_cmd(dep, cmd, &params);
425 }
426 
427 static dma_addr_t dwc3_trb_dma_offset(struct dwc3_ep *dep,
428 		struct dwc3_trb *trb)
429 {
430 	u32		offset = (char *) trb - (char *) dep->trb_pool;
431 
432 	return dep->trb_pool_dma + offset;
433 }
434 
435 static int dwc3_alloc_trb_pool(struct dwc3_ep *dep)
436 {
437 	struct dwc3		*dwc = dep->dwc;
438 
439 	if (dep->trb_pool)
440 		return 0;
441 
442 	dep->trb_pool = dma_alloc_coherent(dwc->sysdev,
443 			sizeof(struct dwc3_trb) * DWC3_TRB_NUM,
444 			&dep->trb_pool_dma, GFP_KERNEL);
445 	if (!dep->trb_pool) {
446 		dev_err(dep->dwc->dev, "failed to allocate trb pool for %s\n",
447 				dep->name);
448 		return -ENOMEM;
449 	}
450 
451 	return 0;
452 }
453 
454 static void dwc3_free_trb_pool(struct dwc3_ep *dep)
455 {
456 	struct dwc3		*dwc = dep->dwc;
457 
458 	dma_free_coherent(dwc->sysdev, sizeof(struct dwc3_trb) * DWC3_TRB_NUM,
459 			dep->trb_pool, dep->trb_pool_dma);
460 
461 	dep->trb_pool = NULL;
462 	dep->trb_pool_dma = 0;
463 }
464 
465 static int dwc3_gadget_set_xfer_resource(struct dwc3_ep *dep)
466 {
467 	struct dwc3_gadget_ep_cmd_params params;
468 
469 	memset(&params, 0x00, sizeof(params));
470 
471 	params.param0 = DWC3_DEPXFERCFG_NUM_XFER_RES(1);
472 
473 	return dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETTRANSFRESOURCE,
474 			&params);
475 }
476 
477 /**
478  * dwc3_gadget_start_config - configure ep resources
479  * @dep: endpoint that is being enabled
480  *
481  * Issue a %DWC3_DEPCMD_DEPSTARTCFG command to @dep. After the command's
482  * completion, it will set Transfer Resource for all available endpoints.
483  *
484  * The assignment of transfer resources cannot perfectly follow the data book
485  * due to the fact that the controller driver does not have all knowledge of the
486  * configuration in advance. It is given this information piecemeal by the
487  * composite gadget framework after every SET_CONFIGURATION and
488  * SET_INTERFACE. Trying to follow the databook programming model in this
489  * scenario can cause errors. For two reasons:
490  *
491  * 1) The databook says to do %DWC3_DEPCMD_DEPSTARTCFG for every
492  * %USB_REQ_SET_CONFIGURATION and %USB_REQ_SET_INTERFACE (8.1.5). This is
493  * incorrect in the scenario of multiple interfaces.
494  *
495  * 2) The databook does not mention doing more %DWC3_DEPCMD_DEPXFERCFG for new
496  * endpoint on alt setting (8.1.6).
497  *
498  * The following simplified method is used instead:
499  *
500  * All hardware endpoints can be assigned a transfer resource and this setting
501  * will stay persistent until either a core reset or hibernation. So whenever we
502  * do a %DWC3_DEPCMD_DEPSTARTCFG(0) we can go ahead and do
503  * %DWC3_DEPCMD_DEPXFERCFG for every hardware endpoint as well. We are
504  * guaranteed that there are as many transfer resources as endpoints.
505  *
506  * This function is called for each endpoint when it is being enabled but is
507  * triggered only when called for EP0-out, which always happens first, and which
508  * should only happen in one of the above conditions.
509  */
510 static int dwc3_gadget_start_config(struct dwc3_ep *dep)
511 {
512 	struct dwc3_gadget_ep_cmd_params params;
513 	struct dwc3		*dwc;
514 	u32			cmd;
515 	int			i;
516 	int			ret;
517 
518 	if (dep->number)
519 		return 0;
520 
521 	memset(&params, 0x00, sizeof(params));
522 	cmd = DWC3_DEPCMD_DEPSTARTCFG;
523 	dwc = dep->dwc;
524 
525 	ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
526 	if (ret)
527 		return ret;
528 
529 	for (i = 0; i < DWC3_ENDPOINTS_NUM; i++) {
530 		struct dwc3_ep *dep = dwc->eps[i];
531 
532 		if (!dep)
533 			continue;
534 
535 		ret = dwc3_gadget_set_xfer_resource(dep);
536 		if (ret)
537 			return ret;
538 	}
539 
540 	return 0;
541 }
542 
543 static int dwc3_gadget_set_ep_config(struct dwc3_ep *dep, unsigned int action)
544 {
545 	const struct usb_ss_ep_comp_descriptor *comp_desc;
546 	const struct usb_endpoint_descriptor *desc;
547 	struct dwc3_gadget_ep_cmd_params params;
548 	struct dwc3 *dwc = dep->dwc;
549 
550 	comp_desc = dep->endpoint.comp_desc;
551 	desc = dep->endpoint.desc;
552 
553 	memset(&params, 0x00, sizeof(params));
554 
555 	params.param0 = DWC3_DEPCFG_EP_TYPE(usb_endpoint_type(desc))
556 		| DWC3_DEPCFG_MAX_PACKET_SIZE(usb_endpoint_maxp(desc));
557 
558 	/* Burst size is only needed in SuperSpeed mode */
559 	if (dwc->gadget.speed >= USB_SPEED_SUPER) {
560 		u32 burst = dep->endpoint.maxburst;
561 		params.param0 |= DWC3_DEPCFG_BURST_SIZE(burst - 1);
562 	}
563 
564 	params.param0 |= action;
565 	if (action == DWC3_DEPCFG_ACTION_RESTORE)
566 		params.param2 |= dep->saved_state;
567 
568 	if (usb_endpoint_xfer_control(desc))
569 		params.param1 = DWC3_DEPCFG_XFER_COMPLETE_EN;
570 
571 	if (dep->number <= 1 || usb_endpoint_xfer_isoc(desc))
572 		params.param1 |= DWC3_DEPCFG_XFER_NOT_READY_EN;
573 
574 	if (usb_ss_max_streams(comp_desc) && usb_endpoint_xfer_bulk(desc)) {
575 		params.param1 |= DWC3_DEPCFG_STREAM_CAPABLE
576 			| DWC3_DEPCFG_STREAM_EVENT_EN;
577 		dep->stream_capable = true;
578 	}
579 
580 	if (!usb_endpoint_xfer_control(desc))
581 		params.param1 |= DWC3_DEPCFG_XFER_IN_PROGRESS_EN;
582 
583 	/*
584 	 * We are doing 1:1 mapping for endpoints, meaning
585 	 * Physical Endpoints 2 maps to Logical Endpoint 2 and
586 	 * so on. We consider the direction bit as part of the physical
587 	 * endpoint number. So USB endpoint 0x81 is 0x03.
588 	 */
589 	params.param1 |= DWC3_DEPCFG_EP_NUMBER(dep->number);
590 
591 	/*
592 	 * We must use the lower 16 TX FIFOs even though
593 	 * HW might have more
594 	 */
595 	if (dep->direction)
596 		params.param0 |= DWC3_DEPCFG_FIFO_NUMBER(dep->number >> 1);
597 
598 	if (desc->bInterval) {
599 		params.param1 |= DWC3_DEPCFG_BINTERVAL_M1(desc->bInterval - 1);
600 		dep->interval = 1 << (desc->bInterval - 1);
601 	}
602 
603 	return dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETEPCONFIG, &params);
604 }
605 
606 /**
607  * __dwc3_gadget_ep_enable - initializes a hw endpoint
608  * @dep: endpoint to be initialized
609  * @action: one of INIT, MODIFY or RESTORE
610  *
611  * Caller should take care of locking. Execute all necessary commands to
612  * initialize a HW endpoint so it can be used by a gadget driver.
613  */
614 static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep, unsigned int action)
615 {
616 	const struct usb_endpoint_descriptor *desc = dep->endpoint.desc;
617 	struct dwc3		*dwc = dep->dwc;
618 
619 	u32			reg;
620 	int			ret;
621 
622 	if (!(dep->flags & DWC3_EP_ENABLED)) {
623 		ret = dwc3_gadget_start_config(dep);
624 		if (ret)
625 			return ret;
626 	}
627 
628 	ret = dwc3_gadget_set_ep_config(dep, action);
629 	if (ret)
630 		return ret;
631 
632 	if (!(dep->flags & DWC3_EP_ENABLED)) {
633 		struct dwc3_trb	*trb_st_hw;
634 		struct dwc3_trb	*trb_link;
635 
636 		dep->type = usb_endpoint_type(desc);
637 		dep->flags |= DWC3_EP_ENABLED;
638 
639 		reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
640 		reg |= DWC3_DALEPENA_EP(dep->number);
641 		dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);
642 
643 		if (usb_endpoint_xfer_control(desc))
644 			goto out;
645 
646 		/* Initialize the TRB ring */
647 		dep->trb_dequeue = 0;
648 		dep->trb_enqueue = 0;
649 		memset(dep->trb_pool, 0,
650 		       sizeof(struct dwc3_trb) * DWC3_TRB_NUM);
651 
652 		/* Link TRB. The HWO bit is never reset */
653 		trb_st_hw = &dep->trb_pool[0];
654 
655 		trb_link = &dep->trb_pool[DWC3_TRB_NUM - 1];
656 		trb_link->bpl = lower_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
657 		trb_link->bph = upper_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
658 		trb_link->ctrl |= DWC3_TRBCTL_LINK_TRB;
659 		trb_link->ctrl |= DWC3_TRB_CTRL_HWO;
660 	}
661 
662 	/*
663 	 * Issue StartTransfer here with no-op TRB so we can always rely on No
664 	 * Response Update Transfer command.
665 	 */
666 	if ((usb_endpoint_xfer_bulk(desc) && !dep->stream_capable) ||
667 			usb_endpoint_xfer_int(desc)) {
668 		struct dwc3_gadget_ep_cmd_params params;
669 		struct dwc3_trb	*trb;
670 		dma_addr_t trb_dma;
671 		u32 cmd;
672 
673 		memset(&params, 0, sizeof(params));
674 		trb = &dep->trb_pool[0];
675 		trb_dma = dwc3_trb_dma_offset(dep, trb);
676 
677 		params.param0 = upper_32_bits(trb_dma);
678 		params.param1 = lower_32_bits(trb_dma);
679 
680 		cmd = DWC3_DEPCMD_STARTTRANSFER;
681 
682 		ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
683 		if (ret < 0)
684 			return ret;
685 	}
686 
687 out:
688 	trace_dwc3_gadget_ep_enable(dep);
689 
690 	return 0;
691 }
692 
693 static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force,
694 		bool interrupt);
695 static void dwc3_remove_requests(struct dwc3 *dwc, struct dwc3_ep *dep)
696 {
697 	struct dwc3_request		*req;
698 
699 	dwc3_stop_active_transfer(dep, true, false);
700 
701 	/* - giveback all requests to gadget driver */
702 	while (!list_empty(&dep->started_list)) {
703 		req = next_request(&dep->started_list);
704 
705 		dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
706 	}
707 
708 	while (!list_empty(&dep->pending_list)) {
709 		req = next_request(&dep->pending_list);
710 
711 		dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
712 	}
713 
714 	while (!list_empty(&dep->cancelled_list)) {
715 		req = next_request(&dep->cancelled_list);
716 
717 		dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
718 	}
719 }
720 
721 /**
722  * __dwc3_gadget_ep_disable - disables a hw endpoint
723  * @dep: the endpoint to disable
724  *
725  * This function undoes what __dwc3_gadget_ep_enable did and also removes
726  * requests which are currently being processed by the hardware and those which
727  * are not yet scheduled.
728  *
729  * Caller should take care of locking.
730  */
731 static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
732 {
733 	struct dwc3		*dwc = dep->dwc;
734 	u32			reg;
735 
736 	trace_dwc3_gadget_ep_disable(dep);
737 
738 	dwc3_remove_requests(dwc, dep);
739 
740 	/* make sure HW endpoint isn't stalled */
741 	if (dep->flags & DWC3_EP_STALL)
742 		__dwc3_gadget_ep_set_halt(dep, 0, false);
743 
744 	reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
745 	reg &= ~DWC3_DALEPENA_EP(dep->number);
746 	dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);
747 
748 	dep->stream_capable = false;
749 	dep->type = 0;
750 	dep->flags = 0;
751 
752 	/* Clear out the ep descriptors for non-ep0 */
753 	if (dep->number > 1) {
754 		dep->endpoint.comp_desc = NULL;
755 		dep->endpoint.desc = NULL;
756 	}
757 
758 	return 0;
759 }
760 
761 /* -------------------------------------------------------------------------- */
762 
763 static int dwc3_gadget_ep0_enable(struct usb_ep *ep,
764 		const struct usb_endpoint_descriptor *desc)
765 {
766 	return -EINVAL;
767 }
768 
769 static int dwc3_gadget_ep0_disable(struct usb_ep *ep)
770 {
771 	return -EINVAL;
772 }
773 
774 /* -------------------------------------------------------------------------- */
775 
776 static int dwc3_gadget_ep_enable(struct usb_ep *ep,
777 		const struct usb_endpoint_descriptor *desc)
778 {
779 	struct dwc3_ep			*dep;
780 	struct dwc3			*dwc;
781 	unsigned long			flags;
782 	int				ret;
783 
784 	if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
785 		pr_debug("dwc3: invalid parameters\n");
786 		return -EINVAL;
787 	}
788 
789 	if (!desc->wMaxPacketSize) {
790 		pr_debug("dwc3: missing wMaxPacketSize\n");
791 		return -EINVAL;
792 	}
793 
794 	dep = to_dwc3_ep(ep);
795 	dwc = dep->dwc;
796 
797 	if (dev_WARN_ONCE(dwc->dev, dep->flags & DWC3_EP_ENABLED,
798 					"%s is already enabled\n",
799 					dep->name))
800 		return 0;
801 
802 	spin_lock_irqsave(&dwc->lock, flags);
803 	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_INIT);
804 	spin_unlock_irqrestore(&dwc->lock, flags);
805 
806 	return ret;
807 }
808 
809 static int dwc3_gadget_ep_disable(struct usb_ep *ep)
810 {
811 	struct dwc3_ep			*dep;
812 	struct dwc3			*dwc;
813 	unsigned long			flags;
814 	int				ret;
815 
816 	if (!ep) {
817 		pr_debug("dwc3: invalid parameters\n");
818 		return -EINVAL;
819 	}
820 
821 	dep = to_dwc3_ep(ep);
822 	dwc = dep->dwc;
823 
824 	if (dev_WARN_ONCE(dwc->dev, !(dep->flags & DWC3_EP_ENABLED),
825 					"%s is already disabled\n",
826 					dep->name))
827 		return 0;
828 
829 	spin_lock_irqsave(&dwc->lock, flags);
830 	ret = __dwc3_gadget_ep_disable(dep);
831 	spin_unlock_irqrestore(&dwc->lock, flags);
832 
833 	return ret;
834 }
835 
836 static struct usb_request *dwc3_gadget_ep_alloc_request(struct usb_ep *ep,
837 		gfp_t gfp_flags)
838 {
839 	struct dwc3_request		*req;
840 	struct dwc3_ep			*dep = to_dwc3_ep(ep);
841 
842 	req = kzalloc(sizeof(*req), gfp_flags);
843 	if (!req)
844 		return NULL;
845 
846 	req->direction	= dep->direction;
847 	req->epnum	= dep->number;
848 	req->dep	= dep;
849 	req->status	= DWC3_REQUEST_STATUS_UNKNOWN;
850 
851 	trace_dwc3_alloc_request(req);
852 
853 	return &req->request;
854 }
855 
856 static void dwc3_gadget_ep_free_request(struct usb_ep *ep,
857 		struct usb_request *request)
858 {
859 	struct dwc3_request		*req = to_dwc3_request(request);
860 
861 	trace_dwc3_free_request(req);
862 	kfree(req);
863 }
864 
865 /**
866  * dwc3_ep_prev_trb - returns the previous TRB in the ring
867  * @dep: The endpoint with the TRB ring
868  * @index: The index of the current TRB in the ring
869  *
870  * Returns the TRB prior to the one pointed to by the index. If the
871  * index is 0, we will wrap backwards, skip the link TRB, and return
872  * the one just before that.
873  */
874 static struct dwc3_trb *dwc3_ep_prev_trb(struct dwc3_ep *dep, u8 index)
875 {
876 	u8 tmp = index;
877 
878 	if (!tmp)
879 		tmp = DWC3_TRB_NUM - 1;
880 
881 	return &dep->trb_pool[tmp - 1];
882 }
883 
884 static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep)
885 {
886 	struct dwc3_trb		*tmp;
887 	u8			trbs_left;
888 
889 	/*
890 	 * If enqueue & dequeue are equal than it is either full or empty.
891 	 *
892 	 * One way to know for sure is if the TRB right before us has HWO bit
893 	 * set or not. If it has, then we're definitely full and can't fit any
894 	 * more transfers in our ring.
895 	 */
896 	if (dep->trb_enqueue == dep->trb_dequeue) {
897 		tmp = dwc3_ep_prev_trb(dep, dep->trb_enqueue);
898 		if (tmp->ctrl & DWC3_TRB_CTRL_HWO)
899 			return 0;
900 
901 		return DWC3_TRB_NUM - 1;
902 	}
903 
904 	trbs_left = dep->trb_dequeue - dep->trb_enqueue;
905 	trbs_left &= (DWC3_TRB_NUM - 1);
906 
907 	if (dep->trb_dequeue < dep->trb_enqueue)
908 		trbs_left--;
909 
910 	return trbs_left;
911 }
912 
913 static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
914 		dma_addr_t dma, unsigned length, unsigned chain, unsigned node,
915 		unsigned stream_id, unsigned short_not_ok, unsigned no_interrupt)
916 {
917 	struct dwc3		*dwc = dep->dwc;
918 	struct usb_gadget	*gadget = &dwc->gadget;
919 	enum usb_device_speed	speed = gadget->speed;
920 
921 	trb->size = DWC3_TRB_SIZE_LENGTH(length);
922 	trb->bpl = lower_32_bits(dma);
923 	trb->bph = upper_32_bits(dma);
924 
925 	switch (usb_endpoint_type(dep->endpoint.desc)) {
926 	case USB_ENDPOINT_XFER_CONTROL:
927 		trb->ctrl = DWC3_TRBCTL_CONTROL_SETUP;
928 		break;
929 
930 	case USB_ENDPOINT_XFER_ISOC:
931 		if (!node) {
932 			trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS_FIRST;
933 
934 			/*
935 			 * USB Specification 2.0 Section 5.9.2 states that: "If
936 			 * there is only a single transaction in the microframe,
937 			 * only a DATA0 data packet PID is used.  If there are
938 			 * two transactions per microframe, DATA1 is used for
939 			 * the first transaction data packet and DATA0 is used
940 			 * for the second transaction data packet.  If there are
941 			 * three transactions per microframe, DATA2 is used for
942 			 * the first transaction data packet, DATA1 is used for
943 			 * the second, and DATA0 is used for the third."
944 			 *
945 			 * IOW, we should satisfy the following cases:
946 			 *
947 			 * 1) length <= maxpacket
948 			 *	- DATA0
949 			 *
950 			 * 2) maxpacket < length <= (2 * maxpacket)
951 			 *	- DATA1, DATA0
952 			 *
953 			 * 3) (2 * maxpacket) < length <= (3 * maxpacket)
954 			 *	- DATA2, DATA1, DATA0
955 			 */
956 			if (speed == USB_SPEED_HIGH) {
957 				struct usb_ep *ep = &dep->endpoint;
958 				unsigned int mult = 2;
959 				unsigned int maxp = usb_endpoint_maxp(ep->desc);
960 
961 				if (length <= (2 * maxp))
962 					mult--;
963 
964 				if (length <= maxp)
965 					mult--;
966 
967 				trb->size |= DWC3_TRB_SIZE_PCM1(mult);
968 			}
969 		} else {
970 			trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS;
971 		}
972 
973 		/* always enable Interrupt on Missed ISOC */
974 		trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;
975 		break;
976 
977 	case USB_ENDPOINT_XFER_BULK:
978 	case USB_ENDPOINT_XFER_INT:
979 		trb->ctrl = DWC3_TRBCTL_NORMAL;
980 		break;
981 	default:
982 		/*
983 		 * This is only possible with faulty memory because we
984 		 * checked it already :)
985 		 */
986 		dev_WARN(dwc->dev, "Unknown endpoint type %d\n",
987 				usb_endpoint_type(dep->endpoint.desc));
988 	}
989 
990 	/*
991 	 * Enable Continue on Short Packet
992 	 * when endpoint is not a stream capable
993 	 */
994 	if (usb_endpoint_dir_out(dep->endpoint.desc)) {
995 		if (!dep->stream_capable)
996 			trb->ctrl |= DWC3_TRB_CTRL_CSP;
997 
998 		if (short_not_ok)
999 			trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;
1000 	}
1001 
1002 	if ((!no_interrupt && !chain) ||
1003 			(dwc3_calc_trbs_left(dep) == 1))
1004 		trb->ctrl |= DWC3_TRB_CTRL_IOC;
1005 
1006 	if (chain)
1007 		trb->ctrl |= DWC3_TRB_CTRL_CHN;
1008 
1009 	if (usb_endpoint_xfer_bulk(dep->endpoint.desc) && dep->stream_capable)
1010 		trb->ctrl |= DWC3_TRB_CTRL_SID_SOFN(stream_id);
1011 
1012 	trb->ctrl |= DWC3_TRB_CTRL_HWO;
1013 
1014 	dwc3_ep_inc_enq(dep);
1015 
1016 	trace_dwc3_prepare_trb(dep, trb);
1017 }
1018 
1019 /**
1020  * dwc3_prepare_one_trb - setup one TRB from one request
1021  * @dep: endpoint for which this request is prepared
1022  * @req: dwc3_request pointer
1023  * @chain: should this TRB be chained to the next?
1024  * @node: only for isochronous endpoints. First TRB needs different type.
1025  */
1026 static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
1027 		struct dwc3_request *req, unsigned chain, unsigned node)
1028 {
1029 	struct dwc3_trb		*trb;
1030 	unsigned int		length;
1031 	dma_addr_t		dma;
1032 	unsigned		stream_id = req->request.stream_id;
1033 	unsigned		short_not_ok = req->request.short_not_ok;
1034 	unsigned		no_interrupt = req->request.no_interrupt;
1035 
1036 	if (req->request.num_sgs > 0) {
1037 		length = sg_dma_len(req->start_sg);
1038 		dma = sg_dma_address(req->start_sg);
1039 	} else {
1040 		length = req->request.length;
1041 		dma = req->request.dma;
1042 	}
1043 
1044 	trb = &dep->trb_pool[dep->trb_enqueue];
1045 
1046 	if (!req->trb) {
1047 		dwc3_gadget_move_started_request(req);
1048 		req->trb = trb;
1049 		req->trb_dma = dwc3_trb_dma_offset(dep, trb);
1050 	}
1051 
1052 	req->num_trbs++;
1053 
1054 	__dwc3_prepare_one_trb(dep, trb, dma, length, chain, node,
1055 			stream_id, short_not_ok, no_interrupt);
1056 }
1057 
1058 static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
1059 		struct dwc3_request *req)
1060 {
1061 	struct scatterlist *sg = req->start_sg;
1062 	struct scatterlist *s;
1063 	int		i;
1064 
1065 	unsigned int remaining = req->request.num_mapped_sgs
1066 		- req->num_queued_sgs;
1067 
1068 	for_each_sg(sg, s, remaining, i) {
1069 		unsigned int length = req->request.length;
1070 		unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
1071 		unsigned int rem = length % maxp;
1072 		unsigned chain = true;
1073 
1074 		if (sg_is_last(s))
1075 			chain = false;
1076 
1077 		if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) {
1078 			struct dwc3	*dwc = dep->dwc;
1079 			struct dwc3_trb	*trb;
1080 
1081 			req->needs_extra_trb = true;
1082 
1083 			/* prepare normal TRB */
1084 			dwc3_prepare_one_trb(dep, req, true, i);
1085 
1086 			/* Now prepare one extra TRB to align transfer size */
1087 			trb = &dep->trb_pool[dep->trb_enqueue];
1088 			req->num_trbs++;
1089 			__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr,
1090 					maxp - rem, false, 1,
1091 					req->request.stream_id,
1092 					req->request.short_not_ok,
1093 					req->request.no_interrupt);
1094 		} else {
1095 			dwc3_prepare_one_trb(dep, req, chain, i);
1096 		}
1097 
1098 		/*
1099 		 * There can be a situation where all sgs in sglist are not
1100 		 * queued because of insufficient trb number. To handle this
1101 		 * case, update start_sg to next sg to be queued, so that
1102 		 * we have free trbs we can continue queuing from where we
1103 		 * previously stopped
1104 		 */
1105 		if (chain)
1106 			req->start_sg = sg_next(s);
1107 
1108 		req->num_queued_sgs++;
1109 
1110 		if (!dwc3_calc_trbs_left(dep))
1111 			break;
1112 	}
1113 }
1114 
1115 static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
1116 		struct dwc3_request *req)
1117 {
1118 	unsigned int length = req->request.length;
1119 	unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
1120 	unsigned int rem = length % maxp;
1121 
1122 	if ((!length || rem) && usb_endpoint_dir_out(dep->endpoint.desc)) {
1123 		struct dwc3	*dwc = dep->dwc;
1124 		struct dwc3_trb	*trb;
1125 
1126 		req->needs_extra_trb = true;
1127 
1128 		/* prepare normal TRB */
1129 		dwc3_prepare_one_trb(dep, req, true, 0);
1130 
1131 		/* Now prepare one extra TRB to align transfer size */
1132 		trb = &dep->trb_pool[dep->trb_enqueue];
1133 		req->num_trbs++;
1134 		__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, maxp - rem,
1135 				false, 1, req->request.stream_id,
1136 				req->request.short_not_ok,
1137 				req->request.no_interrupt);
1138 	} else if (req->request.zero && req->request.length &&
1139 		   (IS_ALIGNED(req->request.length, maxp))) {
1140 		struct dwc3	*dwc = dep->dwc;
1141 		struct dwc3_trb	*trb;
1142 
1143 		req->needs_extra_trb = true;
1144 
1145 		/* prepare normal TRB */
1146 		dwc3_prepare_one_trb(dep, req, true, 0);
1147 
1148 		/* Now prepare one extra TRB to handle ZLP */
1149 		trb = &dep->trb_pool[dep->trb_enqueue];
1150 		req->num_trbs++;
1151 		__dwc3_prepare_one_trb(dep, trb, dwc->bounce_addr, 0,
1152 				false, 1, req->request.stream_id,
1153 				req->request.short_not_ok,
1154 				req->request.no_interrupt);
1155 	} else {
1156 		dwc3_prepare_one_trb(dep, req, false, 0);
1157 	}
1158 }
1159 
1160 /*
1161  * dwc3_prepare_trbs - setup TRBs from requests
1162  * @dep: endpoint for which requests are being prepared
1163  *
1164  * The function goes through the requests list and sets up TRBs for the
1165  * transfers. The function returns once there are no more TRBs available or
1166  * it runs out of requests.
1167  */
1168 static void dwc3_prepare_trbs(struct dwc3_ep *dep)
1169 {
1170 	struct dwc3_request	*req, *n;
1171 
1172 	BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);
1173 
1174 	/*
1175 	 * We can get in a situation where there's a request in the started list
1176 	 * but there weren't enough TRBs to fully kick it in the first time
1177 	 * around, so it has been waiting for more TRBs to be freed up.
1178 	 *
1179 	 * In that case, we should check if we have a request with pending_sgs
1180 	 * in the started list and prepare TRBs for that request first,
1181 	 * otherwise we will prepare TRBs completely out of order and that will
1182 	 * break things.
1183 	 */
1184 	list_for_each_entry(req, &dep->started_list, list) {
1185 		if (req->num_pending_sgs > 0)
1186 			dwc3_prepare_one_trb_sg(dep, req);
1187 
1188 		if (!dwc3_calc_trbs_left(dep))
1189 			return;
1190 	}
1191 
1192 	list_for_each_entry_safe(req, n, &dep->pending_list, list) {
1193 		struct dwc3	*dwc = dep->dwc;
1194 		int		ret;
1195 
1196 		ret = usb_gadget_map_request_by_dev(dwc->sysdev, &req->request,
1197 						    dep->direction);
1198 		if (ret)
1199 			return;
1200 
1201 		req->sg			= req->request.sg;
1202 		req->start_sg		= req->sg;
1203 		req->num_queued_sgs	= 0;
1204 		req->num_pending_sgs	= req->request.num_mapped_sgs;
1205 
1206 		if (req->num_pending_sgs > 0)
1207 			dwc3_prepare_one_trb_sg(dep, req);
1208 		else
1209 			dwc3_prepare_one_trb_linear(dep, req);
1210 
1211 		if (!dwc3_calc_trbs_left(dep))
1212 			return;
1213 	}
1214 }
1215 
1216 static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep)
1217 {
1218 	struct dwc3_gadget_ep_cmd_params params;
1219 	struct dwc3_request		*req;
1220 	int				starting;
1221 	int				ret;
1222 	u32				cmd;
1223 
1224 	if (!dwc3_calc_trbs_left(dep))
1225 		return 0;
1226 
1227 	starting = !(dep->flags & DWC3_EP_TRANSFER_STARTED);
1228 
1229 	dwc3_prepare_trbs(dep);
1230 	req = next_request(&dep->started_list);
1231 	if (!req) {
1232 		dep->flags |= DWC3_EP_PENDING_REQUEST;
1233 		return 0;
1234 	}
1235 
1236 	memset(&params, 0, sizeof(params));
1237 
1238 	if (starting) {
1239 		params.param0 = upper_32_bits(req->trb_dma);
1240 		params.param1 = lower_32_bits(req->trb_dma);
1241 		cmd = DWC3_DEPCMD_STARTTRANSFER;
1242 
1243 		if (dep->stream_capable)
1244 			cmd |= DWC3_DEPCMD_PARAM(req->request.stream_id);
1245 
1246 		if (usb_endpoint_xfer_isoc(dep->endpoint.desc))
1247 			cmd |= DWC3_DEPCMD_PARAM(dep->frame_number);
1248 	} else {
1249 		cmd = DWC3_DEPCMD_UPDATETRANSFER |
1250 			DWC3_DEPCMD_PARAM(dep->resource_index);
1251 	}
1252 
1253 	ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
1254 	if (ret < 0) {
1255 		/*
1256 		 * FIXME we need to iterate over the list of requests
1257 		 * here and stop, unmap, free and del each of the linked
1258 		 * requests instead of what we do now.
1259 		 */
1260 		if (req->trb)
1261 			memset(req->trb, 0, sizeof(struct dwc3_trb));
1262 		dwc3_gadget_del_and_unmap_request(dep, req, ret);
1263 		return ret;
1264 	}
1265 
1266 	return 0;
1267 }
1268 
1269 static int __dwc3_gadget_get_frame(struct dwc3 *dwc)
1270 {
1271 	u32			reg;
1272 
1273 	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
1274 	return DWC3_DSTS_SOFFN(reg);
1275 }
1276 
1277 /**
1278  * dwc3_gadget_start_isoc_quirk - workaround invalid frame number
1279  * @dep: isoc endpoint
1280  *
1281  * This function tests for the correct combination of BIT[15:14] from the 16-bit
1282  * microframe number reported by the XferNotReady event for the future frame
1283  * number to start the isoc transfer.
1284  *
1285  * In DWC_usb31 version 1.70a-ea06 and prior, for highspeed and fullspeed
1286  * isochronous IN, BIT[15:14] of the 16-bit microframe number reported by the
1287  * XferNotReady event are invalid. The driver uses this number to schedule the
1288  * isochronous transfer and passes it to the START TRANSFER command. Because
1289  * this number is invalid, the command may fail. If BIT[15:14] matches the
1290  * internal 16-bit microframe, the START TRANSFER command will pass and the
1291  * transfer will start at the scheduled time, if it is off by 1, the command
1292  * will still pass, but the transfer will start 2 seconds in the future. For all
1293  * other conditions, the START TRANSFER command will fail with bus-expiry.
1294  *
1295  * In order to workaround this issue, we can test for the correct combination of
1296  * BIT[15:14] by sending START TRANSFER commands with different values of
1297  * BIT[15:14]: 'b00, 'b01, 'b10, and 'b11. Each combination is 2^14 uframe apart
1298  * (or 2 seconds). 4 seconds into the future will result in a bus-expiry status.
1299  * As the result, within the 4 possible combinations for BIT[15:14], there will
1300  * be 2 successful and 2 failure START COMMAND status. One of the 2 successful
1301  * command status will result in a 2-second delay start. The smaller BIT[15:14]
1302  * value is the correct combination.
1303  *
1304  * Since there are only 4 outcomes and the results are ordered, we can simply
1305  * test 2 START TRANSFER commands with BIT[15:14] combinations 'b00 and 'b01 to
1306  * deduce the smaller successful combination.
1307  *
1308  * Let test0 = test status for combination 'b00 and test1 = test status for 'b01
1309  * of BIT[15:14]. The correct combination is as follow:
1310  *
1311  * if test0 fails and test1 passes, BIT[15:14] is 'b01
1312  * if test0 fails and test1 fails, BIT[15:14] is 'b10
1313  * if test0 passes and test1 fails, BIT[15:14] is 'b11
1314  * if test0 passes and test1 passes, BIT[15:14] is 'b00
1315  *
1316  * Synopsys STAR 9001202023: Wrong microframe number for isochronous IN
1317  * endpoints.
1318  */
1319 static int dwc3_gadget_start_isoc_quirk(struct dwc3_ep *dep)
1320 {
1321 	int cmd_status = 0;
1322 	bool test0;
1323 	bool test1;
1324 
1325 	while (dep->combo_num < 2) {
1326 		struct dwc3_gadget_ep_cmd_params params;
1327 		u32 test_frame_number;
1328 		u32 cmd;
1329 
1330 		/*
1331 		 * Check if we can start isoc transfer on the next interval or
1332 		 * 4 uframes in the future with BIT[15:14] as dep->combo_num
1333 		 */
1334 		test_frame_number = dep->frame_number & 0x3fff;
1335 		test_frame_number |= dep->combo_num << 14;
1336 		test_frame_number += max_t(u32, 4, dep->interval);
1337 
1338 		params.param0 = upper_32_bits(dep->dwc->bounce_addr);
1339 		params.param1 = lower_32_bits(dep->dwc->bounce_addr);
1340 
1341 		cmd = DWC3_DEPCMD_STARTTRANSFER;
1342 		cmd |= DWC3_DEPCMD_PARAM(test_frame_number);
1343 		cmd_status = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
1344 
1345 		/* Redo if some other failure beside bus-expiry is received */
1346 		if (cmd_status && cmd_status != -EAGAIN) {
1347 			dep->start_cmd_status = 0;
1348 			dep->combo_num = 0;
1349 			return 0;
1350 		}
1351 
1352 		/* Store the first test status */
1353 		if (dep->combo_num == 0)
1354 			dep->start_cmd_status = cmd_status;
1355 
1356 		dep->combo_num++;
1357 
1358 		/*
1359 		 * End the transfer if the START_TRANSFER command is successful
1360 		 * to wait for the next XferNotReady to test the command again
1361 		 */
1362 		if (cmd_status == 0) {
1363 			dwc3_stop_active_transfer(dep, true, true);
1364 			return 0;
1365 		}
1366 	}
1367 
1368 	/* test0 and test1 are both completed at this point */
1369 	test0 = (dep->start_cmd_status == 0);
1370 	test1 = (cmd_status == 0);
1371 
1372 	if (!test0 && test1)
1373 		dep->combo_num = 1;
1374 	else if (!test0 && !test1)
1375 		dep->combo_num = 2;
1376 	else if (test0 && !test1)
1377 		dep->combo_num = 3;
1378 	else if (test0 && test1)
1379 		dep->combo_num = 0;
1380 
1381 	dep->frame_number &= 0x3fff;
1382 	dep->frame_number |= dep->combo_num << 14;
1383 	dep->frame_number += max_t(u32, 4, dep->interval);
1384 
1385 	/* Reinitialize test variables */
1386 	dep->start_cmd_status = 0;
1387 	dep->combo_num = 0;
1388 
1389 	return __dwc3_gadget_kick_transfer(dep);
1390 }
1391 
1392 static int __dwc3_gadget_start_isoc(struct dwc3_ep *dep)
1393 {
1394 	struct dwc3 *dwc = dep->dwc;
1395 	int ret;
1396 	int i;
1397 
1398 	if (list_empty(&dep->pending_list)) {
1399 		dep->flags |= DWC3_EP_PENDING_REQUEST;
1400 		return -EAGAIN;
1401 	}
1402 
1403 	if (!dwc->dis_start_transfer_quirk && dwc3_is_usb31(dwc) &&
1404 	    (dwc->revision <= DWC3_USB31_REVISION_160A ||
1405 	     (dwc->revision == DWC3_USB31_REVISION_170A &&
1406 	      dwc->version_type >= DWC31_VERSIONTYPE_EA01 &&
1407 	      dwc->version_type <= DWC31_VERSIONTYPE_EA06))) {
1408 
1409 		if (dwc->gadget.speed <= USB_SPEED_HIGH && dep->direction)
1410 			return dwc3_gadget_start_isoc_quirk(dep);
1411 	}
1412 
1413 	for (i = 0; i < DWC3_ISOC_MAX_RETRIES; i++) {
1414 		dep->frame_number = DWC3_ALIGN_FRAME(dep, i + 1);
1415 
1416 		ret = __dwc3_gadget_kick_transfer(dep);
1417 		if (ret != -EAGAIN)
1418 			break;
1419 	}
1420 
1421 	return ret;
1422 }
1423 
1424 static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
1425 {
1426 	struct dwc3		*dwc = dep->dwc;
1427 
1428 	if (!dep->endpoint.desc) {
1429 		dev_err(dwc->dev, "%s: can't queue to disabled endpoint\n",
1430 				dep->name);
1431 		return -ESHUTDOWN;
1432 	}
1433 
1434 	if (WARN(req->dep != dep, "request %pK belongs to '%s'\n",
1435 				&req->request, req->dep->name))
1436 		return -EINVAL;
1437 
1438 	if (WARN(req->status < DWC3_REQUEST_STATUS_COMPLETED,
1439 				"%s: request %pK already in flight\n",
1440 				dep->name, &req->request))
1441 		return -EINVAL;
1442 
1443 	pm_runtime_get(dwc->dev);
1444 
1445 	req->request.actual	= 0;
1446 	req->request.status	= -EINPROGRESS;
1447 
1448 	trace_dwc3_ep_queue(req);
1449 
1450 	list_add_tail(&req->list, &dep->pending_list);
1451 	req->status = DWC3_REQUEST_STATUS_QUEUED;
1452 
1453 	/* Start the transfer only after the END_TRANSFER is completed */
1454 	if (dep->flags & DWC3_EP_END_TRANSFER_PENDING) {
1455 		dep->flags |= DWC3_EP_DELAY_START;
1456 		return 0;
1457 	}
1458 
1459 	/*
1460 	 * NOTICE: Isochronous endpoints should NEVER be prestarted. We must
1461 	 * wait for a XferNotReady event so we will know what's the current
1462 	 * (micro-)frame number.
1463 	 *
1464 	 * Without this trick, we are very, very likely gonna get Bus Expiry
1465 	 * errors which will force us issue EndTransfer command.
1466 	 */
1467 	if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
1468 		if (!(dep->flags & DWC3_EP_PENDING_REQUEST) &&
1469 				!(dep->flags & DWC3_EP_TRANSFER_STARTED))
1470 			return 0;
1471 
1472 		if ((dep->flags & DWC3_EP_PENDING_REQUEST)) {
1473 			if (!(dep->flags & DWC3_EP_TRANSFER_STARTED)) {
1474 				return __dwc3_gadget_start_isoc(dep);
1475 			}
1476 		}
1477 	}
1478 
1479 	return __dwc3_gadget_kick_transfer(dep);
1480 }
1481 
1482 static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
1483 	gfp_t gfp_flags)
1484 {
1485 	struct dwc3_request		*req = to_dwc3_request(request);
1486 	struct dwc3_ep			*dep = to_dwc3_ep(ep);
1487 	struct dwc3			*dwc = dep->dwc;
1488 
1489 	unsigned long			flags;
1490 
1491 	int				ret;
1492 
1493 	spin_lock_irqsave(&dwc->lock, flags);
1494 	ret = __dwc3_gadget_ep_queue(dep, req);
1495 	spin_unlock_irqrestore(&dwc->lock, flags);
1496 
1497 	return ret;
1498 }
1499 
1500 static void dwc3_gadget_ep_skip_trbs(struct dwc3_ep *dep, struct dwc3_request *req)
1501 {
1502 	int i;
1503 
1504 	/*
1505 	 * If request was already started, this means we had to
1506 	 * stop the transfer. With that we also need to ignore
1507 	 * all TRBs used by the request, however TRBs can only
1508 	 * be modified after completion of END_TRANSFER
1509 	 * command. So what we do here is that we wait for
1510 	 * END_TRANSFER completion and only after that, we jump
1511 	 * over TRBs by clearing HWO and incrementing dequeue
1512 	 * pointer.
1513 	 */
1514 	for (i = 0; i < req->num_trbs; i++) {
1515 		struct dwc3_trb *trb;
1516 
1517 		trb = req->trb + i;
1518 		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
1519 		dwc3_ep_inc_deq(dep);
1520 	}
1521 
1522 	req->num_trbs = 0;
1523 }
1524 
1525 static void dwc3_gadget_ep_cleanup_cancelled_requests(struct dwc3_ep *dep)
1526 {
1527 	struct dwc3_request		*req;
1528 	struct dwc3_request		*tmp;
1529 
1530 	list_for_each_entry_safe(req, tmp, &dep->cancelled_list, list) {
1531 		dwc3_gadget_ep_skip_trbs(dep, req);
1532 		dwc3_gadget_giveback(dep, req, -ECONNRESET);
1533 	}
1534 }
1535 
1536 static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
1537 		struct usb_request *request)
1538 {
1539 	struct dwc3_request		*req = to_dwc3_request(request);
1540 	struct dwc3_request		*r = NULL;
1541 
1542 	struct dwc3_ep			*dep = to_dwc3_ep(ep);
1543 	struct dwc3			*dwc = dep->dwc;
1544 
1545 	unsigned long			flags;
1546 	int				ret = 0;
1547 
1548 	trace_dwc3_ep_dequeue(req);
1549 
1550 	spin_lock_irqsave(&dwc->lock, flags);
1551 
1552 	list_for_each_entry(r, &dep->pending_list, list) {
1553 		if (r == req)
1554 			break;
1555 	}
1556 
1557 	if (r != req) {
1558 		list_for_each_entry(r, &dep->started_list, list) {
1559 			if (r == req)
1560 				break;
1561 		}
1562 		if (r == req) {
1563 			/* wait until it is processed */
1564 			dwc3_stop_active_transfer(dep, true, true);
1565 
1566 			if (!r->trb)
1567 				goto out0;
1568 
1569 			dwc3_gadget_move_cancelled_request(req);
1570 			if (dep->flags & DWC3_EP_TRANSFER_STARTED)
1571 				goto out0;
1572 			else
1573 				goto out1;
1574 		}
1575 		dev_err(dwc->dev, "request %pK was not queued to %s\n",
1576 				request, ep->name);
1577 		ret = -EINVAL;
1578 		goto out0;
1579 	}
1580 
1581 out1:
1582 	dwc3_gadget_giveback(dep, req, -ECONNRESET);
1583 
1584 out0:
1585 	spin_unlock_irqrestore(&dwc->lock, flags);
1586 
1587 	return ret;
1588 }
1589 
1590 int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
1591 {
1592 	struct dwc3_gadget_ep_cmd_params	params;
1593 	struct dwc3				*dwc = dep->dwc;
1594 	int					ret;
1595 
1596 	if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
1597 		dev_err(dwc->dev, "%s is of Isochronous type\n", dep->name);
1598 		return -EINVAL;
1599 	}
1600 
1601 	memset(&params, 0x00, sizeof(params));
1602 
1603 	if (value) {
1604 		struct dwc3_trb *trb;
1605 
1606 		unsigned transfer_in_flight;
1607 		unsigned started;
1608 
1609 		if (dep->number > 1)
1610 			trb = dwc3_ep_prev_trb(dep, dep->trb_enqueue);
1611 		else
1612 			trb = &dwc->ep0_trb[dep->trb_enqueue];
1613 
1614 		transfer_in_flight = trb->ctrl & DWC3_TRB_CTRL_HWO;
1615 		started = !list_empty(&dep->started_list);
1616 
1617 		if (!protocol && ((dep->direction && transfer_in_flight) ||
1618 				(!dep->direction && started))) {
1619 			return -EAGAIN;
1620 		}
1621 
1622 		ret = dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETSTALL,
1623 				&params);
1624 		if (ret)
1625 			dev_err(dwc->dev, "failed to set STALL on %s\n",
1626 					dep->name);
1627 		else
1628 			dep->flags |= DWC3_EP_STALL;
1629 	} else {
1630 
1631 		ret = dwc3_send_clear_stall_ep_cmd(dep);
1632 		if (ret)
1633 			dev_err(dwc->dev, "failed to clear STALL on %s\n",
1634 					dep->name);
1635 		else
1636 			dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE);
1637 	}
1638 
1639 	return ret;
1640 }
1641 
1642 static int dwc3_gadget_ep_set_halt(struct usb_ep *ep, int value)
1643 {
1644 	struct dwc3_ep			*dep = to_dwc3_ep(ep);
1645 	struct dwc3			*dwc = dep->dwc;
1646 
1647 	unsigned long			flags;
1648 
1649 	int				ret;
1650 
1651 	spin_lock_irqsave(&dwc->lock, flags);
1652 	ret = __dwc3_gadget_ep_set_halt(dep, value, false);
1653 	spin_unlock_irqrestore(&dwc->lock, flags);
1654 
1655 	return ret;
1656 }
1657 
1658 static int dwc3_gadget_ep_set_wedge(struct usb_ep *ep)
1659 {
1660 	struct dwc3_ep			*dep = to_dwc3_ep(ep);
1661 	struct dwc3			*dwc = dep->dwc;
1662 	unsigned long			flags;
1663 	int				ret;
1664 
1665 	spin_lock_irqsave(&dwc->lock, flags);
1666 	dep->flags |= DWC3_EP_WEDGE;
1667 
1668 	if (dep->number == 0 || dep->number == 1)
1669 		ret = __dwc3_gadget_ep0_set_halt(ep, 1);
1670 	else
1671 		ret = __dwc3_gadget_ep_set_halt(dep, 1, false);
1672 	spin_unlock_irqrestore(&dwc->lock, flags);
1673 
1674 	return ret;
1675 }
1676 
1677 /* -------------------------------------------------------------------------- */
1678 
1679 static struct usb_endpoint_descriptor dwc3_gadget_ep0_desc = {
1680 	.bLength	= USB_DT_ENDPOINT_SIZE,
1681 	.bDescriptorType = USB_DT_ENDPOINT,
1682 	.bmAttributes	= USB_ENDPOINT_XFER_CONTROL,
1683 };
1684 
1685 static const struct usb_ep_ops dwc3_gadget_ep0_ops = {
1686 	.enable		= dwc3_gadget_ep0_enable,
1687 	.disable	= dwc3_gadget_ep0_disable,
1688 	.alloc_request	= dwc3_gadget_ep_alloc_request,
1689 	.free_request	= dwc3_gadget_ep_free_request,
1690 	.queue		= dwc3_gadget_ep0_queue,
1691 	.dequeue	= dwc3_gadget_ep_dequeue,
1692 	.set_halt	= dwc3_gadget_ep0_set_halt,
1693 	.set_wedge	= dwc3_gadget_ep_set_wedge,
1694 };
1695 
1696 static const struct usb_ep_ops dwc3_gadget_ep_ops = {
1697 	.enable		= dwc3_gadget_ep_enable,
1698 	.disable	= dwc3_gadget_ep_disable,
1699 	.alloc_request	= dwc3_gadget_ep_alloc_request,
1700 	.free_request	= dwc3_gadget_ep_free_request,
1701 	.queue		= dwc3_gadget_ep_queue,
1702 	.dequeue	= dwc3_gadget_ep_dequeue,
1703 	.set_halt	= dwc3_gadget_ep_set_halt,
1704 	.set_wedge	= dwc3_gadget_ep_set_wedge,
1705 };
1706 
1707 /* -------------------------------------------------------------------------- */
1708 
1709 static int dwc3_gadget_get_frame(struct usb_gadget *g)
1710 {
1711 	struct dwc3		*dwc = gadget_to_dwc(g);
1712 
1713 	return __dwc3_gadget_get_frame(dwc);
1714 }
1715 
1716 static int __dwc3_gadget_wakeup(struct dwc3 *dwc)
1717 {
1718 	int			retries;
1719 
1720 	int			ret;
1721 	u32			reg;
1722 
1723 	u8			link_state;
1724 	u8			speed;
1725 
1726 	/*
1727 	 * According to the Databook Remote wakeup request should
1728 	 * be issued only when the device is in early suspend state.
1729 	 *
1730 	 * We can check that via USB Link State bits in DSTS register.
1731 	 */
1732 	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
1733 
1734 	speed = reg & DWC3_DSTS_CONNECTSPD;
1735 	if ((speed == DWC3_DSTS_SUPERSPEED) ||
1736 	    (speed == DWC3_DSTS_SUPERSPEED_PLUS))
1737 		return 0;
1738 
1739 	link_state = DWC3_DSTS_USBLNKST(reg);
1740 
1741 	switch (link_state) {
1742 	case DWC3_LINK_STATE_RX_DET:	/* in HS, means Early Suspend */
1743 	case DWC3_LINK_STATE_U3:	/* in HS, means SUSPEND */
1744 		break;
1745 	default:
1746 		return -EINVAL;
1747 	}
1748 
1749 	ret = dwc3_gadget_set_link_state(dwc, DWC3_LINK_STATE_RECOV);
1750 	if (ret < 0) {
1751 		dev_err(dwc->dev, "failed to put link in Recovery\n");
1752 		return ret;
1753 	}
1754 
1755 	/* Recent versions do this automatically */
1756 	if (dwc->revision < DWC3_REVISION_194A) {
1757 		/* write zeroes to Link Change Request */
1758 		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
1759 		reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
1760 		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
1761 	}
1762 
1763 	/* poll until Link State changes to ON */
1764 	retries = 20000;
1765 
1766 	while (retries--) {
1767 		reg = dwc3_readl(dwc->regs, DWC3_DSTS);
1768 
1769 		/* in HS, means ON */
1770 		if (DWC3_DSTS_USBLNKST(reg) == DWC3_LINK_STATE_U0)
1771 			break;
1772 	}
1773 
1774 	if (DWC3_DSTS_USBLNKST(reg) != DWC3_LINK_STATE_U0) {
1775 		dev_err(dwc->dev, "failed to send remote wakeup\n");
1776 		return -EINVAL;
1777 	}
1778 
1779 	return 0;
1780 }
1781 
1782 static int dwc3_gadget_wakeup(struct usb_gadget *g)
1783 {
1784 	struct dwc3		*dwc = gadget_to_dwc(g);
1785 	unsigned long		flags;
1786 	int			ret;
1787 
1788 	spin_lock_irqsave(&dwc->lock, flags);
1789 	ret = __dwc3_gadget_wakeup(dwc);
1790 	spin_unlock_irqrestore(&dwc->lock, flags);
1791 
1792 	return ret;
1793 }
1794 
1795 static int dwc3_gadget_set_selfpowered(struct usb_gadget *g,
1796 		int is_selfpowered)
1797 {
1798 	struct dwc3		*dwc = gadget_to_dwc(g);
1799 	unsigned long		flags;
1800 
1801 	spin_lock_irqsave(&dwc->lock, flags);
1802 	g->is_selfpowered = !!is_selfpowered;
1803 	spin_unlock_irqrestore(&dwc->lock, flags);
1804 
1805 	return 0;
1806 }
1807 
1808 static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
1809 {
1810 	u32			reg;
1811 	u32			timeout = 500;
1812 
1813 	if (pm_runtime_suspended(dwc->dev))
1814 		return 0;
1815 
1816 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
1817 	if (is_on) {
1818 		if (dwc->revision <= DWC3_REVISION_187A) {
1819 			reg &= ~DWC3_DCTL_TRGTULST_MASK;
1820 			reg |= DWC3_DCTL_TRGTULST_RX_DET;
1821 		}
1822 
1823 		if (dwc->revision >= DWC3_REVISION_194A)
1824 			reg &= ~DWC3_DCTL_KEEP_CONNECT;
1825 		reg |= DWC3_DCTL_RUN_STOP;
1826 
1827 		if (dwc->has_hibernation)
1828 			reg |= DWC3_DCTL_KEEP_CONNECT;
1829 
1830 		dwc->pullups_connected = true;
1831 	} else {
1832 		reg &= ~DWC3_DCTL_RUN_STOP;
1833 
1834 		if (dwc->has_hibernation && !suspend)
1835 			reg &= ~DWC3_DCTL_KEEP_CONNECT;
1836 
1837 		dwc->pullups_connected = false;
1838 	}
1839 
1840 	dwc3_gadget_dctl_write_safe(dwc, reg);
1841 
1842 	do {
1843 		reg = dwc3_readl(dwc->regs, DWC3_DSTS);
1844 		reg &= DWC3_DSTS_DEVCTRLHLT;
1845 	} while (--timeout && !(!is_on ^ !reg));
1846 
1847 	if (!timeout)
1848 		return -ETIMEDOUT;
1849 
1850 	return 0;
1851 }
1852 
1853 static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
1854 {
1855 	struct dwc3		*dwc = gadget_to_dwc(g);
1856 	unsigned long		flags;
1857 	int			ret;
1858 
1859 	is_on = !!is_on;
1860 
1861 	/*
1862 	 * Per databook, when we want to stop the gadget, if a control transfer
1863 	 * is still in process, complete it and get the core into setup phase.
1864 	 */
1865 	if (!is_on && dwc->ep0state != EP0_SETUP_PHASE) {
1866 		reinit_completion(&dwc->ep0_in_setup);
1867 
1868 		ret = wait_for_completion_timeout(&dwc->ep0_in_setup,
1869 				msecs_to_jiffies(DWC3_PULL_UP_TIMEOUT));
1870 		if (ret == 0) {
1871 			dev_err(dwc->dev, "timed out waiting for SETUP phase\n");
1872 			return -ETIMEDOUT;
1873 		}
1874 	}
1875 
1876 	spin_lock_irqsave(&dwc->lock, flags);
1877 	ret = dwc3_gadget_run_stop(dwc, is_on, false);
1878 	spin_unlock_irqrestore(&dwc->lock, flags);
1879 
1880 	return ret;
1881 }
1882 
1883 static void dwc3_gadget_enable_irq(struct dwc3 *dwc)
1884 {
1885 	u32			reg;
1886 
1887 	/* Enable all but Start and End of Frame IRQs */
1888 	reg = (DWC3_DEVTEN_VNDRDEVTSTRCVEDEN |
1889 			DWC3_DEVTEN_EVNTOVERFLOWEN |
1890 			DWC3_DEVTEN_CMDCMPLTEN |
1891 			DWC3_DEVTEN_ERRTICERREN |
1892 			DWC3_DEVTEN_WKUPEVTEN |
1893 			DWC3_DEVTEN_CONNECTDONEEN |
1894 			DWC3_DEVTEN_USBRSTEN |
1895 			DWC3_DEVTEN_DISCONNEVTEN);
1896 
1897 	if (dwc->revision < DWC3_REVISION_250A)
1898 		reg |= DWC3_DEVTEN_ULSTCNGEN;
1899 
1900 	dwc3_writel(dwc->regs, DWC3_DEVTEN, reg);
1901 }
1902 
1903 static void dwc3_gadget_disable_irq(struct dwc3 *dwc)
1904 {
1905 	/* mask all interrupts */
1906 	dwc3_writel(dwc->regs, DWC3_DEVTEN, 0x00);
1907 }
1908 
1909 static irqreturn_t dwc3_interrupt(int irq, void *_dwc);
1910 static irqreturn_t dwc3_thread_interrupt(int irq, void *_dwc);
1911 
1912 /**
1913  * dwc3_gadget_setup_nump - calculate and initialize NUMP field of %DWC3_DCFG
1914  * @dwc: pointer to our context structure
1915  *
1916  * The following looks like complex but it's actually very simple. In order to
1917  * calculate the number of packets we can burst at once on OUT transfers, we're
1918  * gonna use RxFIFO size.
1919  *
1920  * To calculate RxFIFO size we need two numbers:
1921  * MDWIDTH = size, in bits, of the internal memory bus
1922  * RAM2_DEPTH = depth, in MDWIDTH, of internal RAM2 (where RxFIFO sits)
1923  *
1924  * Given these two numbers, the formula is simple:
1925  *
1926  * RxFIFO Size = (RAM2_DEPTH * MDWIDTH / 8) - 24 - 16;
1927  *
1928  * 24 bytes is for 3x SETUP packets
1929  * 16 bytes is a clock domain crossing tolerance
1930  *
1931  * Given RxFIFO Size, NUMP = RxFIFOSize / 1024;
1932  */
1933 static void dwc3_gadget_setup_nump(struct dwc3 *dwc)
1934 {
1935 	u32 ram2_depth;
1936 	u32 mdwidth;
1937 	u32 nump;
1938 	u32 reg;
1939 
1940 	ram2_depth = DWC3_GHWPARAMS7_RAM2_DEPTH(dwc->hwparams.hwparams7);
1941 	mdwidth = DWC3_GHWPARAMS0_MDWIDTH(dwc->hwparams.hwparams0);
1942 
1943 	nump = ((ram2_depth * mdwidth / 8) - 24 - 16) / 1024;
1944 	nump = min_t(u32, nump, 16);
1945 
1946 	/* update NumP */
1947 	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
1948 	reg &= ~DWC3_DCFG_NUMP_MASK;
1949 	reg |= nump << DWC3_DCFG_NUMP_SHIFT;
1950 	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
1951 }
1952 
1953 static int __dwc3_gadget_start(struct dwc3 *dwc)
1954 {
1955 	struct dwc3_ep		*dep;
1956 	int			ret = 0;
1957 	u32			reg;
1958 
1959 	/*
1960 	 * Use IMOD if enabled via dwc->imod_interval. Otherwise, if
1961 	 * the core supports IMOD, disable it.
1962 	 */
1963 	if (dwc->imod_interval) {
1964 		dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval);
1965 		dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), DWC3_GEVNTCOUNT_EHB);
1966 	} else if (dwc3_has_imod(dwc)) {
1967 		dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), 0);
1968 	}
1969 
1970 	/*
1971 	 * We are telling dwc3 that we want to use DCFG.NUMP as ACK TP's NUMP
1972 	 * field instead of letting dwc3 itself calculate that automatically.
1973 	 *
1974 	 * This way, we maximize the chances that we'll be able to get several
1975 	 * bursts of data without going through any sort of endpoint throttling.
1976 	 */
1977 	reg = dwc3_readl(dwc->regs, DWC3_GRXTHRCFG);
1978 	if (dwc3_is_usb31(dwc))
1979 		reg &= ~DWC31_GRXTHRCFG_PKTCNTSEL;
1980 	else
1981 		reg &= ~DWC3_GRXTHRCFG_PKTCNTSEL;
1982 
1983 	dwc3_writel(dwc->regs, DWC3_GRXTHRCFG, reg);
1984 
1985 	dwc3_gadget_setup_nump(dwc);
1986 
1987 	/* Start with SuperSpeed Default */
1988 	dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
1989 
1990 	dep = dwc->eps[0];
1991 	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_INIT);
1992 	if (ret) {
1993 		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
1994 		goto err0;
1995 	}
1996 
1997 	dep = dwc->eps[1];
1998 	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_INIT);
1999 	if (ret) {
2000 		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
2001 		goto err1;
2002 	}
2003 
2004 	/* begin to receive SETUP packets */
2005 	dwc->ep0state = EP0_SETUP_PHASE;
2006 	dwc->link_state = DWC3_LINK_STATE_SS_DIS;
2007 	dwc3_ep0_out_start(dwc);
2008 
2009 	dwc3_gadget_enable_irq(dwc);
2010 
2011 	return 0;
2012 
2013 err1:
2014 	__dwc3_gadget_ep_disable(dwc->eps[0]);
2015 
2016 err0:
2017 	return ret;
2018 }
2019 
2020 static int dwc3_gadget_start(struct usb_gadget *g,
2021 		struct usb_gadget_driver *driver)
2022 {
2023 	struct dwc3		*dwc = gadget_to_dwc(g);
2024 	unsigned long		flags;
2025 	int			ret = 0;
2026 	int			irq;
2027 
2028 	irq = dwc->irq_gadget;
2029 	ret = request_threaded_irq(irq, dwc3_interrupt, dwc3_thread_interrupt,
2030 			IRQF_SHARED, "dwc3", dwc->ev_buf);
2031 	if (ret) {
2032 		dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
2033 				irq, ret);
2034 		goto err0;
2035 	}
2036 
2037 	spin_lock_irqsave(&dwc->lock, flags);
2038 	if (dwc->gadget_driver) {
2039 		dev_err(dwc->dev, "%s is already bound to %s\n",
2040 				dwc->gadget.name,
2041 				dwc->gadget_driver->driver.name);
2042 		ret = -EBUSY;
2043 		goto err1;
2044 	}
2045 
2046 	dwc->gadget_driver	= driver;
2047 
2048 	if (pm_runtime_active(dwc->dev))
2049 		__dwc3_gadget_start(dwc);
2050 
2051 	spin_unlock_irqrestore(&dwc->lock, flags);
2052 
2053 	return 0;
2054 
2055 err1:
2056 	spin_unlock_irqrestore(&dwc->lock, flags);
2057 	free_irq(irq, dwc);
2058 
2059 err0:
2060 	return ret;
2061 }
2062 
2063 static void __dwc3_gadget_stop(struct dwc3 *dwc)
2064 {
2065 	dwc3_gadget_disable_irq(dwc);
2066 	__dwc3_gadget_ep_disable(dwc->eps[0]);
2067 	__dwc3_gadget_ep_disable(dwc->eps[1]);
2068 }
2069 
2070 static int dwc3_gadget_stop(struct usb_gadget *g)
2071 {
2072 	struct dwc3		*dwc = gadget_to_dwc(g);
2073 	unsigned long		flags;
2074 
2075 	spin_lock_irqsave(&dwc->lock, flags);
2076 
2077 	if (pm_runtime_suspended(dwc->dev))
2078 		goto out;
2079 
2080 	__dwc3_gadget_stop(dwc);
2081 
2082 out:
2083 	dwc->gadget_driver	= NULL;
2084 	spin_unlock_irqrestore(&dwc->lock, flags);
2085 
2086 	free_irq(dwc->irq_gadget, dwc->ev_buf);
2087 
2088 	return 0;
2089 }
2090 
2091 static void dwc3_gadget_config_params(struct usb_gadget *g,
2092 				      struct usb_dcd_config_params *params)
2093 {
2094 	struct dwc3		*dwc = gadget_to_dwc(g);
2095 
2096 	params->besl_baseline = USB_DEFAULT_BESL_UNSPECIFIED;
2097 	params->besl_deep = USB_DEFAULT_BESL_UNSPECIFIED;
2098 
2099 	/* Recommended BESL */
2100 	if (!dwc->dis_enblslpm_quirk) {
2101 		/*
2102 		 * If the recommended BESL baseline is 0 or if the BESL deep is
2103 		 * less than 2, Microsoft's Windows 10 host usb stack will issue
2104 		 * a usb reset immediately after it receives the extended BOS
2105 		 * descriptor and the enumeration will fail. To maintain
2106 		 * compatibility with the Windows' usb stack, let's set the
2107 		 * recommended BESL baseline to 1 and clamp the BESL deep to be
2108 		 * within 2 to 15.
2109 		 */
2110 		params->besl_baseline = 1;
2111 		if (dwc->is_utmi_l1_suspend)
2112 			params->besl_deep =
2113 				clamp_t(u8, dwc->hird_threshold, 2, 15);
2114 	}
2115 
2116 	/* U1 Device exit Latency */
2117 	if (dwc->dis_u1_entry_quirk)
2118 		params->bU1devExitLat = 0;
2119 	else
2120 		params->bU1devExitLat = DWC3_DEFAULT_U1_DEV_EXIT_LAT;
2121 
2122 	/* U2 Device exit Latency */
2123 	if (dwc->dis_u2_entry_quirk)
2124 		params->bU2DevExitLat = 0;
2125 	else
2126 		params->bU2DevExitLat =
2127 				cpu_to_le16(DWC3_DEFAULT_U2_DEV_EXIT_LAT);
2128 }
2129 
2130 static void dwc3_gadget_set_speed(struct usb_gadget *g,
2131 				  enum usb_device_speed speed)
2132 {
2133 	struct dwc3		*dwc = gadget_to_dwc(g);
2134 	unsigned long		flags;
2135 	u32			reg;
2136 
2137 	spin_lock_irqsave(&dwc->lock, flags);
2138 	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
2139 	reg &= ~(DWC3_DCFG_SPEED_MASK);
2140 
2141 	/*
2142 	 * WORKAROUND: DWC3 revision < 2.20a have an issue
2143 	 * which would cause metastability state on Run/Stop
2144 	 * bit if we try to force the IP to USB2-only mode.
2145 	 *
2146 	 * Because of that, we cannot configure the IP to any
2147 	 * speed other than the SuperSpeed
2148 	 *
2149 	 * Refers to:
2150 	 *
2151 	 * STAR#9000525659: Clock Domain Crossing on DCTL in
2152 	 * USB 2.0 Mode
2153 	 */
2154 	if (dwc->revision < DWC3_REVISION_220A &&
2155 	    !dwc->dis_metastability_quirk) {
2156 		reg |= DWC3_DCFG_SUPERSPEED;
2157 	} else {
2158 		switch (speed) {
2159 		case USB_SPEED_LOW:
2160 			reg |= DWC3_DCFG_LOWSPEED;
2161 			break;
2162 		case USB_SPEED_FULL:
2163 			reg |= DWC3_DCFG_FULLSPEED;
2164 			break;
2165 		case USB_SPEED_HIGH:
2166 			reg |= DWC3_DCFG_HIGHSPEED;
2167 			break;
2168 		case USB_SPEED_SUPER:
2169 			reg |= DWC3_DCFG_SUPERSPEED;
2170 			break;
2171 		case USB_SPEED_SUPER_PLUS:
2172 			if (dwc3_is_usb31(dwc))
2173 				reg |= DWC3_DCFG_SUPERSPEED_PLUS;
2174 			else
2175 				reg |= DWC3_DCFG_SUPERSPEED;
2176 			break;
2177 		default:
2178 			dev_err(dwc->dev, "invalid speed (%d)\n", speed);
2179 
2180 			if (dwc->revision & DWC3_REVISION_IS_DWC31)
2181 				reg |= DWC3_DCFG_SUPERSPEED_PLUS;
2182 			else
2183 				reg |= DWC3_DCFG_SUPERSPEED;
2184 		}
2185 	}
2186 	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
2187 
2188 	spin_unlock_irqrestore(&dwc->lock, flags);
2189 }
2190 
2191 static const struct usb_gadget_ops dwc3_gadget_ops = {
2192 	.get_frame		= dwc3_gadget_get_frame,
2193 	.wakeup			= dwc3_gadget_wakeup,
2194 	.set_selfpowered	= dwc3_gadget_set_selfpowered,
2195 	.pullup			= dwc3_gadget_pullup,
2196 	.udc_start		= dwc3_gadget_start,
2197 	.udc_stop		= dwc3_gadget_stop,
2198 	.udc_set_speed		= dwc3_gadget_set_speed,
2199 	.get_config_params	= dwc3_gadget_config_params,
2200 };
2201 
2202 /* -------------------------------------------------------------------------- */
2203 
2204 static int dwc3_gadget_init_control_endpoint(struct dwc3_ep *dep)
2205 {
2206 	struct dwc3 *dwc = dep->dwc;
2207 
2208 	usb_ep_set_maxpacket_limit(&dep->endpoint, 512);
2209 	dep->endpoint.maxburst = 1;
2210 	dep->endpoint.ops = &dwc3_gadget_ep0_ops;
2211 	if (!dep->direction)
2212 		dwc->gadget.ep0 = &dep->endpoint;
2213 
2214 	dep->endpoint.caps.type_control = true;
2215 
2216 	return 0;
2217 }
2218 
2219 static int dwc3_gadget_init_in_endpoint(struct dwc3_ep *dep)
2220 {
2221 	struct dwc3 *dwc = dep->dwc;
2222 	int mdwidth;
2223 	int kbytes;
2224 	int size;
2225 
2226 	mdwidth = DWC3_MDWIDTH(dwc->hwparams.hwparams0);
2227 	/* MDWIDTH is represented in bits, we need it in bytes */
2228 	mdwidth /= 8;
2229 
2230 	size = dwc3_readl(dwc->regs, DWC3_GTXFIFOSIZ(dep->number >> 1));
2231 	if (dwc3_is_usb31(dwc))
2232 		size = DWC31_GTXFIFOSIZ_TXFDEF(size);
2233 	else
2234 		size = DWC3_GTXFIFOSIZ_TXFDEF(size);
2235 
2236 	/* FIFO Depth is in MDWDITH bytes. Multiply */
2237 	size *= mdwidth;
2238 
2239 	kbytes = size / 1024;
2240 	if (kbytes == 0)
2241 		kbytes = 1;
2242 
2243 	/*
2244 	 * FIFO sizes account an extra MDWIDTH * (kbytes + 1) bytes for
2245 	 * internal overhead. We don't really know how these are used,
2246 	 * but documentation say it exists.
2247 	 */
2248 	size -= mdwidth * (kbytes + 1);
2249 	size /= kbytes;
2250 
2251 	usb_ep_set_maxpacket_limit(&dep->endpoint, size);
2252 
2253 	dep->endpoint.max_streams = 15;
2254 	dep->endpoint.ops = &dwc3_gadget_ep_ops;
2255 	list_add_tail(&dep->endpoint.ep_list,
2256 			&dwc->gadget.ep_list);
2257 	dep->endpoint.caps.type_iso = true;
2258 	dep->endpoint.caps.type_bulk = true;
2259 	dep->endpoint.caps.type_int = true;
2260 
2261 	return dwc3_alloc_trb_pool(dep);
2262 }
2263 
2264 static int dwc3_gadget_init_out_endpoint(struct dwc3_ep *dep)
2265 {
2266 	struct dwc3 *dwc = dep->dwc;
2267 
2268 	usb_ep_set_maxpacket_limit(&dep->endpoint, 1024);
2269 	dep->endpoint.max_streams = 15;
2270 	dep->endpoint.ops = &dwc3_gadget_ep_ops;
2271 	list_add_tail(&dep->endpoint.ep_list,
2272 			&dwc->gadget.ep_list);
2273 	dep->endpoint.caps.type_iso = true;
2274 	dep->endpoint.caps.type_bulk = true;
2275 	dep->endpoint.caps.type_int = true;
2276 
2277 	return dwc3_alloc_trb_pool(dep);
2278 }
2279 
2280 static int dwc3_gadget_init_endpoint(struct dwc3 *dwc, u8 epnum)
2281 {
2282 	struct dwc3_ep			*dep;
2283 	bool				direction = epnum & 1;
2284 	int				ret;
2285 	u8				num = epnum >> 1;
2286 
2287 	dep = kzalloc(sizeof(*dep), GFP_KERNEL);
2288 	if (!dep)
2289 		return -ENOMEM;
2290 
2291 	dep->dwc = dwc;
2292 	dep->number = epnum;
2293 	dep->direction = direction;
2294 	dep->regs = dwc->regs + DWC3_DEP_BASE(epnum);
2295 	dwc->eps[epnum] = dep;
2296 	dep->combo_num = 0;
2297 	dep->start_cmd_status = 0;
2298 
2299 	snprintf(dep->name, sizeof(dep->name), "ep%u%s", num,
2300 			direction ? "in" : "out");
2301 
2302 	dep->endpoint.name = dep->name;
2303 
2304 	if (!(dep->number > 1)) {
2305 		dep->endpoint.desc = &dwc3_gadget_ep0_desc;
2306 		dep->endpoint.comp_desc = NULL;
2307 	}
2308 
2309 	if (num == 0)
2310 		ret = dwc3_gadget_init_control_endpoint(dep);
2311 	else if (direction)
2312 		ret = dwc3_gadget_init_in_endpoint(dep);
2313 	else
2314 		ret = dwc3_gadget_init_out_endpoint(dep);
2315 
2316 	if (ret)
2317 		return ret;
2318 
2319 	dep->endpoint.caps.dir_in = direction;
2320 	dep->endpoint.caps.dir_out = !direction;
2321 
2322 	INIT_LIST_HEAD(&dep->pending_list);
2323 	INIT_LIST_HEAD(&dep->started_list);
2324 	INIT_LIST_HEAD(&dep->cancelled_list);
2325 
2326 	return 0;
2327 }
2328 
2329 static int dwc3_gadget_init_endpoints(struct dwc3 *dwc, u8 total)
2330 {
2331 	u8				epnum;
2332 
2333 	INIT_LIST_HEAD(&dwc->gadget.ep_list);
2334 
2335 	for (epnum = 0; epnum < total; epnum++) {
2336 		int			ret;
2337 
2338 		ret = dwc3_gadget_init_endpoint(dwc, epnum);
2339 		if (ret)
2340 			return ret;
2341 	}
2342 
2343 	return 0;
2344 }
2345 
2346 static void dwc3_gadget_free_endpoints(struct dwc3 *dwc)
2347 {
2348 	struct dwc3_ep			*dep;
2349 	u8				epnum;
2350 
2351 	for (epnum = 0; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
2352 		dep = dwc->eps[epnum];
2353 		if (!dep)
2354 			continue;
2355 		/*
2356 		 * Physical endpoints 0 and 1 are special; they form the
2357 		 * bi-directional USB endpoint 0.
2358 		 *
2359 		 * For those two physical endpoints, we don't allocate a TRB
2360 		 * pool nor do we add them the endpoints list. Due to that, we
2361 		 * shouldn't do these two operations otherwise we would end up
2362 		 * with all sorts of bugs when removing dwc3.ko.
2363 		 */
2364 		if (epnum != 0 && epnum != 1) {
2365 			dwc3_free_trb_pool(dep);
2366 			list_del(&dep->endpoint.ep_list);
2367 		}
2368 
2369 		kfree(dep);
2370 	}
2371 }
2372 
2373 /* -------------------------------------------------------------------------- */
2374 
2375 static int dwc3_gadget_ep_reclaim_completed_trb(struct dwc3_ep *dep,
2376 		struct dwc3_request *req, struct dwc3_trb *trb,
2377 		const struct dwc3_event_depevt *event, int status, int chain)
2378 {
2379 	unsigned int		count;
2380 
2381 	dwc3_ep_inc_deq(dep);
2382 
2383 	trace_dwc3_complete_trb(dep, trb);
2384 	req->num_trbs--;
2385 
2386 	/*
2387 	 * If we're in the middle of series of chained TRBs and we
2388 	 * receive a short transfer along the way, DWC3 will skip
2389 	 * through all TRBs including the last TRB in the chain (the
2390 	 * where CHN bit is zero. DWC3 will also avoid clearing HWO
2391 	 * bit and SW has to do it manually.
2392 	 *
2393 	 * We're going to do that here to avoid problems of HW trying
2394 	 * to use bogus TRBs for transfers.
2395 	 */
2396 	if (chain && (trb->ctrl & DWC3_TRB_CTRL_HWO))
2397 		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
2398 
2399 	/*
2400 	 * For isochronous transfers, the first TRB in a service interval must
2401 	 * have the Isoc-First type. Track and report its interval frame number.
2402 	 */
2403 	if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
2404 	    (trb->ctrl & DWC3_TRBCTL_ISOCHRONOUS_FIRST)) {
2405 		unsigned int frame_number;
2406 
2407 		frame_number = DWC3_TRB_CTRL_GET_SID_SOFN(trb->ctrl);
2408 		frame_number &= ~(dep->interval - 1);
2409 		req->request.frame_number = frame_number;
2410 	}
2411 
2412 	/*
2413 	 * If we're dealing with unaligned size OUT transfer, we will be left
2414 	 * with one TRB pending in the ring. We need to manually clear HWO bit
2415 	 * from that TRB.
2416 	 */
2417 
2418 	if (req->needs_extra_trb && !(trb->ctrl & DWC3_TRB_CTRL_CHN)) {
2419 		trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
2420 		return 1;
2421 	}
2422 
2423 	count = trb->size & DWC3_TRB_SIZE_MASK;
2424 	req->remaining += count;
2425 
2426 	if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN)
2427 		return 1;
2428 
2429 	if (event->status & DEPEVT_STATUS_SHORT && !chain)
2430 		return 1;
2431 
2432 	if (event->status & DEPEVT_STATUS_IOC)
2433 		return 1;
2434 
2435 	return 0;
2436 }
2437 
2438 static int dwc3_gadget_ep_reclaim_trb_sg(struct dwc3_ep *dep,
2439 		struct dwc3_request *req, const struct dwc3_event_depevt *event,
2440 		int status)
2441 {
2442 	struct dwc3_trb *trb = &dep->trb_pool[dep->trb_dequeue];
2443 	struct scatterlist *sg = req->sg;
2444 	struct scatterlist *s;
2445 	unsigned int pending = req->num_pending_sgs;
2446 	unsigned int i;
2447 	int ret = 0;
2448 
2449 	for_each_sg(sg, s, pending, i) {
2450 		trb = &dep->trb_pool[dep->trb_dequeue];
2451 
2452 		if (trb->ctrl & DWC3_TRB_CTRL_HWO)
2453 			break;
2454 
2455 		req->sg = sg_next(s);
2456 		req->num_pending_sgs--;
2457 
2458 		ret = dwc3_gadget_ep_reclaim_completed_trb(dep, req,
2459 				trb, event, status, true);
2460 		if (ret)
2461 			break;
2462 	}
2463 
2464 	return ret;
2465 }
2466 
2467 static int dwc3_gadget_ep_reclaim_trb_linear(struct dwc3_ep *dep,
2468 		struct dwc3_request *req, const struct dwc3_event_depevt *event,
2469 		int status)
2470 {
2471 	struct dwc3_trb *trb = &dep->trb_pool[dep->trb_dequeue];
2472 
2473 	return dwc3_gadget_ep_reclaim_completed_trb(dep, req, trb,
2474 			event, status, false);
2475 }
2476 
2477 static bool dwc3_gadget_ep_request_completed(struct dwc3_request *req)
2478 {
2479 	/*
2480 	 * For OUT direction, host may send less than the setup
2481 	 * length. Return true for all OUT requests.
2482 	 */
2483 	if (!req->direction)
2484 		return true;
2485 
2486 	return req->request.actual == req->request.length;
2487 }
2488 
2489 static int dwc3_gadget_ep_cleanup_completed_request(struct dwc3_ep *dep,
2490 		const struct dwc3_event_depevt *event,
2491 		struct dwc3_request *req, int status)
2492 {
2493 	int ret;
2494 
2495 	if (req->num_pending_sgs)
2496 		ret = dwc3_gadget_ep_reclaim_trb_sg(dep, req, event,
2497 				status);
2498 	else
2499 		ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event,
2500 				status);
2501 
2502 	if (req->needs_extra_trb) {
2503 		ret = dwc3_gadget_ep_reclaim_trb_linear(dep, req, event,
2504 				status);
2505 		req->needs_extra_trb = false;
2506 	}
2507 
2508 	req->request.actual = req->request.length - req->remaining;
2509 
2510 	if (!dwc3_gadget_ep_request_completed(req) ||
2511 			req->num_pending_sgs) {
2512 		__dwc3_gadget_kick_transfer(dep);
2513 		goto out;
2514 	}
2515 
2516 	dwc3_gadget_giveback(dep, req, status);
2517 
2518 out:
2519 	return ret;
2520 }
2521 
2522 static void dwc3_gadget_ep_cleanup_completed_requests(struct dwc3_ep *dep,
2523 		const struct dwc3_event_depevt *event, int status)
2524 {
2525 	struct dwc3_request	*req;
2526 	struct dwc3_request	*tmp;
2527 
2528 	list_for_each_entry_safe(req, tmp, &dep->started_list, list) {
2529 		int ret;
2530 
2531 		ret = dwc3_gadget_ep_cleanup_completed_request(dep, event,
2532 				req, status);
2533 		if (ret)
2534 			break;
2535 	}
2536 }
2537 
2538 static void dwc3_gadget_endpoint_frame_from_event(struct dwc3_ep *dep,
2539 		const struct dwc3_event_depevt *event)
2540 {
2541 	dep->frame_number = event->parameters;
2542 }
2543 
2544 static void dwc3_gadget_endpoint_transfer_in_progress(struct dwc3_ep *dep,
2545 		const struct dwc3_event_depevt *event)
2546 {
2547 	struct dwc3		*dwc = dep->dwc;
2548 	unsigned		status = 0;
2549 	bool			stop = false;
2550 
2551 	dwc3_gadget_endpoint_frame_from_event(dep, event);
2552 
2553 	if (event->status & DEPEVT_STATUS_BUSERR)
2554 		status = -ECONNRESET;
2555 
2556 	if (event->status & DEPEVT_STATUS_MISSED_ISOC) {
2557 		status = -EXDEV;
2558 
2559 		if (list_empty(&dep->started_list))
2560 			stop = true;
2561 	}
2562 
2563 	dwc3_gadget_ep_cleanup_completed_requests(dep, event, status);
2564 
2565 	if (stop) {
2566 		dwc3_stop_active_transfer(dep, true, true);
2567 		dep->flags = DWC3_EP_ENABLED;
2568 	}
2569 
2570 	/*
2571 	 * WORKAROUND: This is the 2nd half of U1/U2 -> U0 workaround.
2572 	 * See dwc3_gadget_linksts_change_interrupt() for 1st half.
2573 	 */
2574 	if (dwc->revision < DWC3_REVISION_183A) {
2575 		u32		reg;
2576 		int		i;
2577 
2578 		for (i = 0; i < DWC3_ENDPOINTS_NUM; i++) {
2579 			dep = dwc->eps[i];
2580 
2581 			if (!(dep->flags & DWC3_EP_ENABLED))
2582 				continue;
2583 
2584 			if (!list_empty(&dep->started_list))
2585 				return;
2586 		}
2587 
2588 		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2589 		reg |= dwc->u1u2;
2590 		dwc3_writel(dwc->regs, DWC3_DCTL, reg);
2591 
2592 		dwc->u1u2 = 0;
2593 	}
2594 }
2595 
2596 static void dwc3_gadget_endpoint_transfer_not_ready(struct dwc3_ep *dep,
2597 		const struct dwc3_event_depevt *event)
2598 {
2599 	dwc3_gadget_endpoint_frame_from_event(dep, event);
2600 	(void) __dwc3_gadget_start_isoc(dep);
2601 }
2602 
2603 static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
2604 		const struct dwc3_event_depevt *event)
2605 {
2606 	struct dwc3_ep		*dep;
2607 	u8			epnum = event->endpoint_number;
2608 	u8			cmd;
2609 
2610 	dep = dwc->eps[epnum];
2611 
2612 	if (!(dep->flags & DWC3_EP_ENABLED)) {
2613 		if (!(dep->flags & DWC3_EP_TRANSFER_STARTED))
2614 			return;
2615 
2616 		/* Handle only EPCMDCMPLT when EP disabled */
2617 		if (event->endpoint_event != DWC3_DEPEVT_EPCMDCMPLT)
2618 			return;
2619 	}
2620 
2621 	if (epnum == 0 || epnum == 1) {
2622 		dwc3_ep0_interrupt(dwc, event);
2623 		return;
2624 	}
2625 
2626 	switch (event->endpoint_event) {
2627 	case DWC3_DEPEVT_XFERINPROGRESS:
2628 		dwc3_gadget_endpoint_transfer_in_progress(dep, event);
2629 		break;
2630 	case DWC3_DEPEVT_XFERNOTREADY:
2631 		dwc3_gadget_endpoint_transfer_not_ready(dep, event);
2632 		break;
2633 	case DWC3_DEPEVT_EPCMDCMPLT:
2634 		cmd = DEPEVT_PARAMETER_CMD(event->parameters);
2635 
2636 		if (cmd == DWC3_DEPCMD_ENDTRANSFER) {
2637 			dep->flags &= ~DWC3_EP_END_TRANSFER_PENDING;
2638 			dep->flags &= ~DWC3_EP_TRANSFER_STARTED;
2639 			dwc3_gadget_ep_cleanup_cancelled_requests(dep);
2640 			if ((dep->flags & DWC3_EP_DELAY_START) &&
2641 			    !usb_endpoint_xfer_isoc(dep->endpoint.desc))
2642 				__dwc3_gadget_kick_transfer(dep);
2643 
2644 			dep->flags &= ~DWC3_EP_DELAY_START;
2645 		}
2646 		break;
2647 	case DWC3_DEPEVT_STREAMEVT:
2648 	case DWC3_DEPEVT_XFERCOMPLETE:
2649 	case DWC3_DEPEVT_RXTXFIFOEVT:
2650 		break;
2651 	}
2652 }
2653 
2654 static void dwc3_disconnect_gadget(struct dwc3 *dwc)
2655 {
2656 	if (dwc->gadget_driver && dwc->gadget_driver->disconnect) {
2657 		spin_unlock(&dwc->lock);
2658 		dwc->gadget_driver->disconnect(&dwc->gadget);
2659 		spin_lock(&dwc->lock);
2660 	}
2661 }
2662 
2663 static void dwc3_suspend_gadget(struct dwc3 *dwc)
2664 {
2665 	if (dwc->gadget_driver && dwc->gadget_driver->suspend) {
2666 		spin_unlock(&dwc->lock);
2667 		dwc->gadget_driver->suspend(&dwc->gadget);
2668 		spin_lock(&dwc->lock);
2669 	}
2670 }
2671 
2672 static void dwc3_resume_gadget(struct dwc3 *dwc)
2673 {
2674 	if (dwc->gadget_driver && dwc->gadget_driver->resume) {
2675 		spin_unlock(&dwc->lock);
2676 		dwc->gadget_driver->resume(&dwc->gadget);
2677 		spin_lock(&dwc->lock);
2678 	}
2679 }
2680 
2681 static void dwc3_reset_gadget(struct dwc3 *dwc)
2682 {
2683 	if (!dwc->gadget_driver)
2684 		return;
2685 
2686 	if (dwc->gadget.speed != USB_SPEED_UNKNOWN) {
2687 		spin_unlock(&dwc->lock);
2688 		usb_gadget_udc_reset(&dwc->gadget, dwc->gadget_driver);
2689 		spin_lock(&dwc->lock);
2690 	}
2691 }
2692 
2693 static void dwc3_stop_active_transfer(struct dwc3_ep *dep, bool force,
2694 	bool interrupt)
2695 {
2696 	struct dwc3_gadget_ep_cmd_params params;
2697 	u32 cmd;
2698 	int ret;
2699 
2700 	if (!(dep->flags & DWC3_EP_TRANSFER_STARTED) ||
2701 	    (dep->flags & DWC3_EP_END_TRANSFER_PENDING))
2702 		return;
2703 
2704 	/*
2705 	 * NOTICE: We are violating what the Databook says about the
2706 	 * EndTransfer command. Ideally we would _always_ wait for the
2707 	 * EndTransfer Command Completion IRQ, but that's causing too
2708 	 * much trouble synchronizing between us and gadget driver.
2709 	 *
2710 	 * We have discussed this with the IP Provider and it was
2711 	 * suggested to giveback all requests here.
2712 	 *
2713 	 * Note also that a similar handling was tested by Synopsys
2714 	 * (thanks a lot Paul) and nothing bad has come out of it.
2715 	 * In short, what we're doing is issuing EndTransfer with
2716 	 * CMDIOC bit set and delay kicking transfer until the
2717 	 * EndTransfer command had completed.
2718 	 *
2719 	 * As of IP version 3.10a of the DWC_usb3 IP, the controller
2720 	 * supports a mode to work around the above limitation. The
2721 	 * software can poll the CMDACT bit in the DEPCMD register
2722 	 * after issuing a EndTransfer command. This mode is enabled
2723 	 * by writing GUCTL2[14]. This polling is already done in the
2724 	 * dwc3_send_gadget_ep_cmd() function so if the mode is
2725 	 * enabled, the EndTransfer command will have completed upon
2726 	 * returning from this function.
2727 	 *
2728 	 * This mode is NOT available on the DWC_usb31 IP.
2729 	 */
2730 
2731 	cmd = DWC3_DEPCMD_ENDTRANSFER;
2732 	cmd |= force ? DWC3_DEPCMD_HIPRI_FORCERM : 0;
2733 	cmd |= interrupt ? DWC3_DEPCMD_CMDIOC : 0;
2734 	cmd |= DWC3_DEPCMD_PARAM(dep->resource_index);
2735 	memset(&params, 0, sizeof(params));
2736 	ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
2737 	WARN_ON_ONCE(ret);
2738 	dep->resource_index = 0;
2739 
2740 	if (!interrupt)
2741 		dep->flags &= ~DWC3_EP_TRANSFER_STARTED;
2742 	else
2743 		dep->flags |= DWC3_EP_END_TRANSFER_PENDING;
2744 }
2745 
2746 static void dwc3_clear_stall_all_ep(struct dwc3 *dwc)
2747 {
2748 	u32 epnum;
2749 
2750 	for (epnum = 1; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
2751 		struct dwc3_ep *dep;
2752 		int ret;
2753 
2754 		dep = dwc->eps[epnum];
2755 		if (!dep)
2756 			continue;
2757 
2758 		if (!(dep->flags & DWC3_EP_STALL))
2759 			continue;
2760 
2761 		dep->flags &= ~DWC3_EP_STALL;
2762 
2763 		ret = dwc3_send_clear_stall_ep_cmd(dep);
2764 		WARN_ON_ONCE(ret);
2765 	}
2766 }
2767 
2768 static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
2769 {
2770 	int			reg;
2771 
2772 	dwc3_gadget_set_link_state(dwc, DWC3_LINK_STATE_RX_DET);
2773 
2774 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2775 	reg &= ~DWC3_DCTL_INITU1ENA;
2776 	reg &= ~DWC3_DCTL_INITU2ENA;
2777 	dwc3_gadget_dctl_write_safe(dwc, reg);
2778 
2779 	dwc3_disconnect_gadget(dwc);
2780 
2781 	dwc->gadget.speed = USB_SPEED_UNKNOWN;
2782 	dwc->setup_packet_pending = false;
2783 	usb_gadget_set_state(&dwc->gadget, USB_STATE_NOTATTACHED);
2784 
2785 	dwc->connected = false;
2786 }
2787 
2788 static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
2789 {
2790 	u32			reg;
2791 
2792 	dwc->connected = true;
2793 
2794 	/*
2795 	 * WORKAROUND: DWC3 revisions <1.88a have an issue which
2796 	 * would cause a missing Disconnect Event if there's a
2797 	 * pending Setup Packet in the FIFO.
2798 	 *
2799 	 * There's no suggested workaround on the official Bug
2800 	 * report, which states that "unless the driver/application
2801 	 * is doing any special handling of a disconnect event,
2802 	 * there is no functional issue".
2803 	 *
2804 	 * Unfortunately, it turns out that we _do_ some special
2805 	 * handling of a disconnect event, namely complete all
2806 	 * pending transfers, notify gadget driver of the
2807 	 * disconnection, and so on.
2808 	 *
2809 	 * Our suggested workaround is to follow the Disconnect
2810 	 * Event steps here, instead, based on a setup_packet_pending
2811 	 * flag. Such flag gets set whenever we have a SETUP_PENDING
2812 	 * status for EP0 TRBs and gets cleared on XferComplete for the
2813 	 * same endpoint.
2814 	 *
2815 	 * Refers to:
2816 	 *
2817 	 * STAR#9000466709: RTL: Device : Disconnect event not
2818 	 * generated if setup packet pending in FIFO
2819 	 */
2820 	if (dwc->revision < DWC3_REVISION_188A) {
2821 		if (dwc->setup_packet_pending)
2822 			dwc3_gadget_disconnect_interrupt(dwc);
2823 	}
2824 
2825 	dwc3_reset_gadget(dwc);
2826 
2827 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2828 	reg &= ~DWC3_DCTL_TSTCTRL_MASK;
2829 	dwc3_gadget_dctl_write_safe(dwc, reg);
2830 	dwc->test_mode = false;
2831 	dwc3_clear_stall_all_ep(dwc);
2832 
2833 	/* Reset device address to zero */
2834 	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
2835 	reg &= ~(DWC3_DCFG_DEVADDR_MASK);
2836 	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
2837 }
2838 
2839 static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
2840 {
2841 	struct dwc3_ep		*dep;
2842 	int			ret;
2843 	u32			reg;
2844 	u8			speed;
2845 
2846 	reg = dwc3_readl(dwc->regs, DWC3_DSTS);
2847 	speed = reg & DWC3_DSTS_CONNECTSPD;
2848 	dwc->speed = speed;
2849 
2850 	/*
2851 	 * RAMClkSel is reset to 0 after USB reset, so it must be reprogrammed
2852 	 * each time on Connect Done.
2853 	 *
2854 	 * Currently we always use the reset value. If any platform
2855 	 * wants to set this to a different value, we need to add a
2856 	 * setting and update GCTL.RAMCLKSEL here.
2857 	 */
2858 
2859 	switch (speed) {
2860 	case DWC3_DSTS_SUPERSPEED_PLUS:
2861 		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
2862 		dwc->gadget.ep0->maxpacket = 512;
2863 		dwc->gadget.speed = USB_SPEED_SUPER_PLUS;
2864 		break;
2865 	case DWC3_DSTS_SUPERSPEED:
2866 		/*
2867 		 * WORKAROUND: DWC3 revisions <1.90a have an issue which
2868 		 * would cause a missing USB3 Reset event.
2869 		 *
2870 		 * In such situations, we should force a USB3 Reset
2871 		 * event by calling our dwc3_gadget_reset_interrupt()
2872 		 * routine.
2873 		 *
2874 		 * Refers to:
2875 		 *
2876 		 * STAR#9000483510: RTL: SS : USB3 reset event may
2877 		 * not be generated always when the link enters poll
2878 		 */
2879 		if (dwc->revision < DWC3_REVISION_190A)
2880 			dwc3_gadget_reset_interrupt(dwc);
2881 
2882 		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
2883 		dwc->gadget.ep0->maxpacket = 512;
2884 		dwc->gadget.speed = USB_SPEED_SUPER;
2885 		break;
2886 	case DWC3_DSTS_HIGHSPEED:
2887 		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(64);
2888 		dwc->gadget.ep0->maxpacket = 64;
2889 		dwc->gadget.speed = USB_SPEED_HIGH;
2890 		break;
2891 	case DWC3_DSTS_FULLSPEED:
2892 		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(64);
2893 		dwc->gadget.ep0->maxpacket = 64;
2894 		dwc->gadget.speed = USB_SPEED_FULL;
2895 		break;
2896 	case DWC3_DSTS_LOWSPEED:
2897 		dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(8);
2898 		dwc->gadget.ep0->maxpacket = 8;
2899 		dwc->gadget.speed = USB_SPEED_LOW;
2900 		break;
2901 	}
2902 
2903 	dwc->eps[1]->endpoint.maxpacket = dwc->gadget.ep0->maxpacket;
2904 
2905 	/* Enable USB2 LPM Capability */
2906 
2907 	if ((dwc->revision > DWC3_REVISION_194A) &&
2908 	    (speed != DWC3_DSTS_SUPERSPEED) &&
2909 	    (speed != DWC3_DSTS_SUPERSPEED_PLUS)) {
2910 		reg = dwc3_readl(dwc->regs, DWC3_DCFG);
2911 		reg |= DWC3_DCFG_LPM_CAP;
2912 		dwc3_writel(dwc->regs, DWC3_DCFG, reg);
2913 
2914 		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2915 		reg &= ~(DWC3_DCTL_HIRD_THRES_MASK | DWC3_DCTL_L1_HIBER_EN);
2916 
2917 		reg |= DWC3_DCTL_HIRD_THRES(dwc->hird_threshold |
2918 					    (dwc->is_utmi_l1_suspend << 4));
2919 
2920 		/*
2921 		 * When dwc3 revisions >= 2.40a, LPM Erratum is enabled and
2922 		 * DCFG.LPMCap is set, core responses with an ACK and the
2923 		 * BESL value in the LPM token is less than or equal to LPM
2924 		 * NYET threshold.
2925 		 */
2926 		WARN_ONCE(dwc->revision < DWC3_REVISION_240A
2927 				&& dwc->has_lpm_erratum,
2928 				"LPM Erratum not available on dwc3 revisions < 2.40a\n");
2929 
2930 		if (dwc->has_lpm_erratum && dwc->revision >= DWC3_REVISION_240A)
2931 			reg |= DWC3_DCTL_NYET_THRES(dwc->lpm_nyet_threshold);
2932 
2933 		dwc3_gadget_dctl_write_safe(dwc, reg);
2934 	} else {
2935 		reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2936 		reg &= ~DWC3_DCTL_HIRD_THRES_MASK;
2937 		dwc3_gadget_dctl_write_safe(dwc, reg);
2938 	}
2939 
2940 	dep = dwc->eps[0];
2941 	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_MODIFY);
2942 	if (ret) {
2943 		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
2944 		return;
2945 	}
2946 
2947 	dep = dwc->eps[1];
2948 	ret = __dwc3_gadget_ep_enable(dep, DWC3_DEPCFG_ACTION_MODIFY);
2949 	if (ret) {
2950 		dev_err(dwc->dev, "failed to enable %s\n", dep->name);
2951 		return;
2952 	}
2953 
2954 	/*
2955 	 * Configure PHY via GUSB3PIPECTLn if required.
2956 	 *
2957 	 * Update GTXFIFOSIZn
2958 	 *
2959 	 * In both cases reset values should be sufficient.
2960 	 */
2961 }
2962 
2963 static void dwc3_gadget_wakeup_interrupt(struct dwc3 *dwc)
2964 {
2965 	/*
2966 	 * TODO take core out of low power mode when that's
2967 	 * implemented.
2968 	 */
2969 
2970 	if (dwc->gadget_driver && dwc->gadget_driver->resume) {
2971 		spin_unlock(&dwc->lock);
2972 		dwc->gadget_driver->resume(&dwc->gadget);
2973 		spin_lock(&dwc->lock);
2974 	}
2975 }
2976 
2977 static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
2978 		unsigned int evtinfo)
2979 {
2980 	enum dwc3_link_state	next = evtinfo & DWC3_LINK_STATE_MASK;
2981 	unsigned int		pwropt;
2982 
2983 	/*
2984 	 * WORKAROUND: DWC3 < 2.50a have an issue when configured without
2985 	 * Hibernation mode enabled which would show up when device detects
2986 	 * host-initiated U3 exit.
2987 	 *
2988 	 * In that case, device will generate a Link State Change Interrupt
2989 	 * from U3 to RESUME which is only necessary if Hibernation is
2990 	 * configured in.
2991 	 *
2992 	 * There are no functional changes due to such spurious event and we
2993 	 * just need to ignore it.
2994 	 *
2995 	 * Refers to:
2996 	 *
2997 	 * STAR#9000570034 RTL: SS Resume event generated in non-Hibernation
2998 	 * operational mode
2999 	 */
3000 	pwropt = DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1);
3001 	if ((dwc->revision < DWC3_REVISION_250A) &&
3002 			(pwropt != DWC3_GHWPARAMS1_EN_PWROPT_HIB)) {
3003 		if ((dwc->link_state == DWC3_LINK_STATE_U3) &&
3004 				(next == DWC3_LINK_STATE_RESUME)) {
3005 			return;
3006 		}
3007 	}
3008 
3009 	/*
3010 	 * WORKAROUND: DWC3 Revisions <1.83a have an issue which, depending
3011 	 * on the link partner, the USB session might do multiple entry/exit
3012 	 * of low power states before a transfer takes place.
3013 	 *
3014 	 * Due to this problem, we might experience lower throughput. The
3015 	 * suggested workaround is to disable DCTL[12:9] bits if we're
3016 	 * transitioning from U1/U2 to U0 and enable those bits again
3017 	 * after a transfer completes and there are no pending transfers
3018 	 * on any of the enabled endpoints.
3019 	 *
3020 	 * This is the first half of that workaround.
3021 	 *
3022 	 * Refers to:
3023 	 *
3024 	 * STAR#9000446952: RTL: Device SS : if U1/U2 ->U0 takes >128us
3025 	 * core send LGO_Ux entering U0
3026 	 */
3027 	if (dwc->revision < DWC3_REVISION_183A) {
3028 		if (next == DWC3_LINK_STATE_U0) {
3029 			u32	u1u2;
3030 			u32	reg;
3031 
3032 			switch (dwc->link_state) {
3033 			case DWC3_LINK_STATE_U1:
3034 			case DWC3_LINK_STATE_U2:
3035 				reg = dwc3_readl(dwc->regs, DWC3_DCTL);
3036 				u1u2 = reg & (DWC3_DCTL_INITU2ENA
3037 						| DWC3_DCTL_ACCEPTU2ENA
3038 						| DWC3_DCTL_INITU1ENA
3039 						| DWC3_DCTL_ACCEPTU1ENA);
3040 
3041 				if (!dwc->u1u2)
3042 					dwc->u1u2 = reg & u1u2;
3043 
3044 				reg &= ~u1u2;
3045 
3046 				dwc3_gadget_dctl_write_safe(dwc, reg);
3047 				break;
3048 			default:
3049 				/* do nothing */
3050 				break;
3051 			}
3052 		}
3053 	}
3054 
3055 	switch (next) {
3056 	case DWC3_LINK_STATE_U1:
3057 		if (dwc->speed == USB_SPEED_SUPER)
3058 			dwc3_suspend_gadget(dwc);
3059 		break;
3060 	case DWC3_LINK_STATE_U2:
3061 	case DWC3_LINK_STATE_U3:
3062 		dwc3_suspend_gadget(dwc);
3063 		break;
3064 	case DWC3_LINK_STATE_RESUME:
3065 		dwc3_resume_gadget(dwc);
3066 		break;
3067 	default:
3068 		/* do nothing */
3069 		break;
3070 	}
3071 
3072 	dwc->link_state = next;
3073 }
3074 
3075 static void dwc3_gadget_suspend_interrupt(struct dwc3 *dwc,
3076 					  unsigned int evtinfo)
3077 {
3078 	enum dwc3_link_state next = evtinfo & DWC3_LINK_STATE_MASK;
3079 
3080 	if (dwc->link_state != next && next == DWC3_LINK_STATE_U3)
3081 		dwc3_suspend_gadget(dwc);
3082 
3083 	dwc->link_state = next;
3084 }
3085 
3086 static void dwc3_gadget_hibernation_interrupt(struct dwc3 *dwc,
3087 		unsigned int evtinfo)
3088 {
3089 	unsigned int is_ss = evtinfo & BIT(4);
3090 
3091 	/*
3092 	 * WORKAROUND: DWC3 revison 2.20a with hibernation support
3093 	 * have a known issue which can cause USB CV TD.9.23 to fail
3094 	 * randomly.
3095 	 *
3096 	 * Because of this issue, core could generate bogus hibernation
3097 	 * events which SW needs to ignore.
3098 	 *
3099 	 * Refers to:
3100 	 *
3101 	 * STAR#9000546576: Device Mode Hibernation: Issue in USB 2.0
3102 	 * Device Fallback from SuperSpeed
3103 	 */
3104 	if (is_ss ^ (dwc->speed == USB_SPEED_SUPER))
3105 		return;
3106 
3107 	/* enter hibernation here */
3108 }
3109 
3110 static void dwc3_gadget_interrupt(struct dwc3 *dwc,
3111 		const struct dwc3_event_devt *event)
3112 {
3113 	switch (event->type) {
3114 	case DWC3_DEVICE_EVENT_DISCONNECT:
3115 		dwc3_gadget_disconnect_interrupt(dwc);
3116 		break;
3117 	case DWC3_DEVICE_EVENT_RESET:
3118 		dwc3_gadget_reset_interrupt(dwc);
3119 		break;
3120 	case DWC3_DEVICE_EVENT_CONNECT_DONE:
3121 		dwc3_gadget_conndone_interrupt(dwc);
3122 		break;
3123 	case DWC3_DEVICE_EVENT_WAKEUP:
3124 		dwc3_gadget_wakeup_interrupt(dwc);
3125 		break;
3126 	case DWC3_DEVICE_EVENT_HIBER_REQ:
3127 		if (dev_WARN_ONCE(dwc->dev, !dwc->has_hibernation,
3128 					"unexpected hibernation event\n"))
3129 			break;
3130 
3131 		dwc3_gadget_hibernation_interrupt(dwc, event->event_info);
3132 		break;
3133 	case DWC3_DEVICE_EVENT_LINK_STATUS_CHANGE:
3134 		dwc3_gadget_linksts_change_interrupt(dwc, event->event_info);
3135 		break;
3136 	case DWC3_DEVICE_EVENT_EOPF:
3137 		/* It changed to be suspend event for version 2.30a and above */
3138 		if (dwc->revision >= DWC3_REVISION_230A) {
3139 			/*
3140 			 * Ignore suspend event until the gadget enters into
3141 			 * USB_STATE_CONFIGURED state.
3142 			 */
3143 			if (dwc->gadget.state >= USB_STATE_CONFIGURED)
3144 				dwc3_gadget_suspend_interrupt(dwc,
3145 						event->event_info);
3146 		}
3147 		break;
3148 	case DWC3_DEVICE_EVENT_SOF:
3149 	case DWC3_DEVICE_EVENT_ERRATIC_ERROR:
3150 	case DWC3_DEVICE_EVENT_CMD_CMPL:
3151 	case DWC3_DEVICE_EVENT_OVERFLOW:
3152 		break;
3153 	default:
3154 		dev_WARN(dwc->dev, "UNKNOWN IRQ %d\n", event->type);
3155 	}
3156 }
3157 
3158 static void dwc3_process_event_entry(struct dwc3 *dwc,
3159 		const union dwc3_event *event)
3160 {
3161 	trace_dwc3_event(event->raw, dwc);
3162 
3163 	if (!event->type.is_devspec)
3164 		dwc3_endpoint_interrupt(dwc, &event->depevt);
3165 	else if (event->type.type == DWC3_EVENT_TYPE_DEV)
3166 		dwc3_gadget_interrupt(dwc, &event->devt);
3167 	else
3168 		dev_err(dwc->dev, "UNKNOWN IRQ type %d\n", event->raw);
3169 }
3170 
3171 static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt)
3172 {
3173 	struct dwc3 *dwc = evt->dwc;
3174 	irqreturn_t ret = IRQ_NONE;
3175 	int left;
3176 	u32 reg;
3177 
3178 	left = evt->count;
3179 
3180 	if (!(evt->flags & DWC3_EVENT_PENDING))
3181 		return IRQ_NONE;
3182 
3183 	while (left > 0) {
3184 		union dwc3_event event;
3185 
3186 		event.raw = *(u32 *) (evt->cache + evt->lpos);
3187 
3188 		dwc3_process_event_entry(dwc, &event);
3189 
3190 		/*
3191 		 * FIXME we wrap around correctly to the next entry as
3192 		 * almost all entries are 4 bytes in size. There is one
3193 		 * entry which has 12 bytes which is a regular entry
3194 		 * followed by 8 bytes data. ATM I don't know how
3195 		 * things are organized if we get next to the a
3196 		 * boundary so I worry about that once we try to handle
3197 		 * that.
3198 		 */
3199 		evt->lpos = (evt->lpos + 4) % evt->length;
3200 		left -= 4;
3201 	}
3202 
3203 	evt->count = 0;
3204 	evt->flags &= ~DWC3_EVENT_PENDING;
3205 	ret = IRQ_HANDLED;
3206 
3207 	/* Unmask interrupt */
3208 	reg = dwc3_readl(dwc->regs, DWC3_GEVNTSIZ(0));
3209 	reg &= ~DWC3_GEVNTSIZ_INTMASK;
3210 	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), reg);
3211 
3212 	if (dwc->imod_interval) {
3213 		dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), DWC3_GEVNTCOUNT_EHB);
3214 		dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval);
3215 	}
3216 
3217 	return ret;
3218 }
3219 
3220 static irqreturn_t dwc3_thread_interrupt(int irq, void *_evt)
3221 {
3222 	struct dwc3_event_buffer *evt = _evt;
3223 	struct dwc3 *dwc = evt->dwc;
3224 	unsigned long flags;
3225 	irqreturn_t ret = IRQ_NONE;
3226 
3227 	spin_lock_irqsave(&dwc->lock, flags);
3228 	ret = dwc3_process_event_buf(evt);
3229 	spin_unlock_irqrestore(&dwc->lock, flags);
3230 
3231 	return ret;
3232 }
3233 
3234 static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt)
3235 {
3236 	struct dwc3 *dwc = evt->dwc;
3237 	u32 amount;
3238 	u32 count;
3239 	u32 reg;
3240 
3241 	if (pm_runtime_suspended(dwc->dev)) {
3242 		pm_runtime_get(dwc->dev);
3243 		disable_irq_nosync(dwc->irq_gadget);
3244 		dwc->pending_events = true;
3245 		return IRQ_HANDLED;
3246 	}
3247 
3248 	/*
3249 	 * With PCIe legacy interrupt, test shows that top-half irq handler can
3250 	 * be called again after HW interrupt deassertion. Check if bottom-half
3251 	 * irq event handler completes before caching new event to prevent
3252 	 * losing events.
3253 	 */
3254 	if (evt->flags & DWC3_EVENT_PENDING)
3255 		return IRQ_HANDLED;
3256 
3257 	count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0));
3258 	count &= DWC3_GEVNTCOUNT_MASK;
3259 	if (!count)
3260 		return IRQ_NONE;
3261 
3262 	evt->count = count;
3263 	evt->flags |= DWC3_EVENT_PENDING;
3264 
3265 	/* Mask interrupt */
3266 	reg = dwc3_readl(dwc->regs, DWC3_GEVNTSIZ(0));
3267 	reg |= DWC3_GEVNTSIZ_INTMASK;
3268 	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), reg);
3269 
3270 	amount = min(count, evt->length - evt->lpos);
3271 	memcpy(evt->cache + evt->lpos, evt->buf + evt->lpos, amount);
3272 
3273 	if (amount < count)
3274 		memcpy(evt->cache, evt->buf, count - amount);
3275 
3276 	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), count);
3277 
3278 	return IRQ_WAKE_THREAD;
3279 }
3280 
3281 static irqreturn_t dwc3_interrupt(int irq, void *_evt)
3282 {
3283 	struct dwc3_event_buffer	*evt = _evt;
3284 
3285 	return dwc3_check_event_buf(evt);
3286 }
3287 
3288 static int dwc3_gadget_get_irq(struct dwc3 *dwc)
3289 {
3290 	struct platform_device *dwc3_pdev = to_platform_device(dwc->dev);
3291 	int irq;
3292 
3293 	irq = platform_get_irq_byname_optional(dwc3_pdev, "peripheral");
3294 	if (irq > 0)
3295 		goto out;
3296 
3297 	if (irq == -EPROBE_DEFER)
3298 		goto out;
3299 
3300 	irq = platform_get_irq_byname_optional(dwc3_pdev, "dwc_usb3");
3301 	if (irq > 0)
3302 		goto out;
3303 
3304 	if (irq == -EPROBE_DEFER)
3305 		goto out;
3306 
3307 	irq = platform_get_irq(dwc3_pdev, 0);
3308 	if (irq > 0)
3309 		goto out;
3310 
3311 	if (!irq)
3312 		irq = -EINVAL;
3313 
3314 out:
3315 	return irq;
3316 }
3317 
3318 /**
3319  * dwc3_gadget_init - initializes gadget related registers
3320  * @dwc: pointer to our controller context structure
3321  *
3322  * Returns 0 on success otherwise negative errno.
3323  */
3324 int dwc3_gadget_init(struct dwc3 *dwc)
3325 {
3326 	int ret;
3327 	int irq;
3328 
3329 	irq = dwc3_gadget_get_irq(dwc);
3330 	if (irq < 0) {
3331 		ret = irq;
3332 		goto err0;
3333 	}
3334 
3335 	dwc->irq_gadget = irq;
3336 
3337 	dwc->ep0_trb = dma_alloc_coherent(dwc->sysdev,
3338 					  sizeof(*dwc->ep0_trb) * 2,
3339 					  &dwc->ep0_trb_addr, GFP_KERNEL);
3340 	if (!dwc->ep0_trb) {
3341 		dev_err(dwc->dev, "failed to allocate ep0 trb\n");
3342 		ret = -ENOMEM;
3343 		goto err0;
3344 	}
3345 
3346 	dwc->setup_buf = kzalloc(DWC3_EP0_SETUP_SIZE, GFP_KERNEL);
3347 	if (!dwc->setup_buf) {
3348 		ret = -ENOMEM;
3349 		goto err1;
3350 	}
3351 
3352 	dwc->bounce = dma_alloc_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE,
3353 			&dwc->bounce_addr, GFP_KERNEL);
3354 	if (!dwc->bounce) {
3355 		ret = -ENOMEM;
3356 		goto err2;
3357 	}
3358 
3359 	init_completion(&dwc->ep0_in_setup);
3360 
3361 	dwc->gadget.ops			= &dwc3_gadget_ops;
3362 	dwc->gadget.speed		= USB_SPEED_UNKNOWN;
3363 	dwc->gadget.sg_supported	= true;
3364 	dwc->gadget.name		= "dwc3-gadget";
3365 	dwc->gadget.lpm_capable		= true;
3366 
3367 	/*
3368 	 * FIXME We might be setting max_speed to <SUPER, however versions
3369 	 * <2.20a of dwc3 have an issue with metastability (documented
3370 	 * elsewhere in this driver) which tells us we can't set max speed to
3371 	 * anything lower than SUPER.
3372 	 *
3373 	 * Because gadget.max_speed is only used by composite.c and function
3374 	 * drivers (i.e. it won't go into dwc3's registers) we are allowing this
3375 	 * to happen so we avoid sending SuperSpeed Capability descriptor
3376 	 * together with our BOS descriptor as that could confuse host into
3377 	 * thinking we can handle super speed.
3378 	 *
3379 	 * Note that, in fact, we won't even support GetBOS requests when speed
3380 	 * is less than super speed because we don't have means, yet, to tell
3381 	 * composite.c that we are USB 2.0 + LPM ECN.
3382 	 */
3383 	if (dwc->revision < DWC3_REVISION_220A &&
3384 	    !dwc->dis_metastability_quirk)
3385 		dev_info(dwc->dev, "changing max_speed on rev %08x\n",
3386 				dwc->revision);
3387 
3388 	dwc->gadget.max_speed		= dwc->maximum_speed;
3389 
3390 	/*
3391 	 * REVISIT: Here we should clear all pending IRQs to be
3392 	 * sure we're starting from a well known location.
3393 	 */
3394 
3395 	ret = dwc3_gadget_init_endpoints(dwc, dwc->num_eps);
3396 	if (ret)
3397 		goto err3;
3398 
3399 	ret = usb_add_gadget_udc(dwc->dev, &dwc->gadget);
3400 	if (ret) {
3401 		dev_err(dwc->dev, "failed to register udc\n");
3402 		goto err4;
3403 	}
3404 
3405 	dwc3_gadget_set_speed(&dwc->gadget, dwc->maximum_speed);
3406 
3407 	return 0;
3408 
3409 err4:
3410 	dwc3_gadget_free_endpoints(dwc);
3411 
3412 err3:
3413 	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
3414 			dwc->bounce_addr);
3415 
3416 err2:
3417 	kfree(dwc->setup_buf);
3418 
3419 err1:
3420 	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
3421 			dwc->ep0_trb, dwc->ep0_trb_addr);
3422 
3423 err0:
3424 	return ret;
3425 }
3426 
3427 /* -------------------------------------------------------------------------- */
3428 
3429 void dwc3_gadget_exit(struct dwc3 *dwc)
3430 {
3431 	usb_del_gadget_udc(&dwc->gadget);
3432 	dwc3_gadget_free_endpoints(dwc);
3433 	dma_free_coherent(dwc->sysdev, DWC3_BOUNCE_SIZE, dwc->bounce,
3434 			  dwc->bounce_addr);
3435 	kfree(dwc->setup_buf);
3436 	dma_free_coherent(dwc->sysdev, sizeof(*dwc->ep0_trb) * 2,
3437 			  dwc->ep0_trb, dwc->ep0_trb_addr);
3438 }
3439 
3440 int dwc3_gadget_suspend(struct dwc3 *dwc)
3441 {
3442 	if (!dwc->gadget_driver)
3443 		return 0;
3444 
3445 	dwc3_gadget_run_stop(dwc, false, false);
3446 	dwc3_disconnect_gadget(dwc);
3447 	__dwc3_gadget_stop(dwc);
3448 
3449 	return 0;
3450 }
3451 
3452 int dwc3_gadget_resume(struct dwc3 *dwc)
3453 {
3454 	int			ret;
3455 
3456 	if (!dwc->gadget_driver)
3457 		return 0;
3458 
3459 	ret = __dwc3_gadget_start(dwc);
3460 	if (ret < 0)
3461 		goto err0;
3462 
3463 	ret = dwc3_gadget_run_stop(dwc, true, false);
3464 	if (ret < 0)
3465 		goto err1;
3466 
3467 	return 0;
3468 
3469 err1:
3470 	__dwc3_gadget_stop(dwc);
3471 
3472 err0:
3473 	return ret;
3474 }
3475 
3476 void dwc3_gadget_process_pending_events(struct dwc3 *dwc)
3477 {
3478 	if (dwc->pending_events) {
3479 		dwc3_interrupt(dwc->irq_gadget, dwc->ev_buf);
3480 		dwc->pending_events = false;
3481 		enable_irq(dwc->irq_gadget);
3482 	}
3483 }
3484