UPSTREAM: usb: dwc3: gadget: pass dep as argument to endpoint command
[firefly-linux-kernel-4.4.55.git] / drivers / usb / dwc3 / gadget.c
1 /**
2  * gadget.c - DesignWare USB3 DRD Controller Gadget Framework Link
3  *
4  * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
5  *
6  * Authors: Felipe Balbi <balbi@ti.com>,
7  *          Sebastian Andrzej Siewior <bigeasy@linutronix.de>
8  *
9  * This program is free software: you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2  of
11  * the License as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  */
18
19 #include <linux/kernel.h>
20 #include <linux/delay.h>
21 #include <linux/slab.h>
22 #include <linux/spinlock.h>
23 #include <linux/platform_device.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/interrupt.h>
26 #include <linux/io.h>
27 #include <linux/list.h>
28 #include <linux/dma-mapping.h>
29
30 #include <linux/usb/ch9.h>
31 #include <linux/usb/gadget.h>
32
33 #include "debug.h"
34 #include "core.h"
35 #include "gadget.h"
36 #include "io.h"
37
38 /**
39  * dwc3_gadget_set_test_mode - Enables USB2 Test Modes
40  * @dwc: pointer to our context structure
41  * @mode: the mode to set (J, K SE0 NAK, Force Enable)
42  *
43  * Caller should take care of locking. This function will
44  * return 0 on success or -EINVAL if wrong Test Selector
45  * is passed
46  */
47 int dwc3_gadget_set_test_mode(struct dwc3 *dwc, int mode)
48 {
49         u32             reg;
50
51         reg = dwc3_readl(dwc->regs, DWC3_DCTL);
52         reg &= ~DWC3_DCTL_TSTCTRL_MASK;
53
54         switch (mode) {
55         case TEST_J:
56         case TEST_K:
57         case TEST_SE0_NAK:
58         case TEST_PACKET:
59         case TEST_FORCE_EN:
60                 reg |= mode << 1;
61                 break;
62         default:
63                 return -EINVAL;
64         }
65
66         dwc3_writel(dwc->regs, DWC3_DCTL, reg);
67
68         return 0;
69 }
70
71 /**
72  * dwc3_gadget_get_link_state - Gets current state of USB Link
73  * @dwc: pointer to our context structure
74  *
75  * Caller should take care of locking. This function will
76  * return the link state on success (>= 0) or -ETIMEDOUT.
77  */
78 int dwc3_gadget_get_link_state(struct dwc3 *dwc)
79 {
80         u32             reg;
81
82         reg = dwc3_readl(dwc->regs, DWC3_DSTS);
83
84         return DWC3_DSTS_USBLNKST(reg);
85 }
86
87 /**
88  * dwc3_gadget_set_link_state - Sets USB Link to a particular State
89  * @dwc: pointer to our context structure
90  * @state: the state to put link into
91  *
92  * Caller should take care of locking. This function will
93  * return 0 on success or -ETIMEDOUT.
94  */
95 int dwc3_gadget_set_link_state(struct dwc3 *dwc, enum dwc3_link_state state)
96 {
97         int             retries = 10000;
98         u32             reg;
99
100         /*
101          * Wait until device controller is ready. Only applies to 1.94a and
102          * later RTL.
103          */
104         if (dwc->revision >= DWC3_REVISION_194A) {
105                 while (--retries) {
106                         reg = dwc3_readl(dwc->regs, DWC3_DSTS);
107                         if (reg & DWC3_DSTS_DCNRD)
108                                 udelay(5);
109                         else
110                                 break;
111                 }
112
113                 if (retries <= 0)
114                         return -ETIMEDOUT;
115         }
116
117         reg = dwc3_readl(dwc->regs, DWC3_DCTL);
118         reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
119
120         /* set requested state */
121         reg |= DWC3_DCTL_ULSTCHNGREQ(state);
122         dwc3_writel(dwc->regs, DWC3_DCTL, reg);
123
124         /*
125          * The following code is racy when called from dwc3_gadget_wakeup,
126          * and is not needed, at least on newer versions
127          */
128         if (dwc->revision >= DWC3_REVISION_194A)
129                 return 0;
130
131         /* wait for a change in DSTS */
132         retries = 10000;
133         while (--retries) {
134                 reg = dwc3_readl(dwc->regs, DWC3_DSTS);
135
136                 if (DWC3_DSTS_USBLNKST(reg) == state)
137                         return 0;
138
139                 udelay(5);
140         }
141
142         dwc3_trace(trace_dwc3_gadget,
143                         "link state change request timed out");
144
145         return -ETIMEDOUT;
146 }
147
148 static void dwc3_ep_inc_enq(struct dwc3_ep *dep)
149 {
150         dep->trb_enqueue++;
151         dep->trb_enqueue %= DWC3_TRB_NUM;
152 }
153
154 static void dwc3_ep_inc_deq(struct dwc3_ep *dep)
155 {
156         dep->trb_dequeue++;
157         dep->trb_dequeue %= DWC3_TRB_NUM;
158 }
159
160 static int dwc3_ep_is_last_trb(unsigned int index)
161 {
162         return index == DWC3_TRB_NUM - 1;
163 }
164
165 void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
166                 int status)
167 {
168         struct dwc3                     *dwc = dep->dwc;
169         int                             i;
170
171         if (req->started) {
172                 i = 0;
173                 do {
174                         dwc3_ep_inc_deq(dep);
175                         /*
176                          * Skip LINK TRB. We can't use req->trb and check for
177                          * DWC3_TRBCTL_LINK_TRB because it points the TRB we
178                          * just completed (not the LINK TRB).
179                          */
180                         if (dwc3_ep_is_last_trb(dep->trb_dequeue))
181                                 dwc3_ep_inc_deq(dep);
182                 } while(++i < req->request.num_mapped_sgs);
183                 req->started = false;
184         }
185         list_del(&req->list);
186         req->trb = NULL;
187
188         if (req->request.status == -EINPROGRESS)
189                 req->request.status = status;
190
191         if (dwc->ep0_bounced && dep->number == 0)
192                 dwc->ep0_bounced = false;
193         else
194                 usb_gadget_unmap_request(&dwc->gadget, &req->request,
195                                 req->direction);
196
197         trace_dwc3_gadget_giveback(req);
198
199         spin_unlock(&dwc->lock);
200         usb_gadget_giveback_request(&dep->endpoint, &req->request);
201         spin_lock(&dwc->lock);
202 }
203
204 int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned cmd, u32 param)
205 {
206         u32             timeout = 500;
207         u32             reg;
208
209         trace_dwc3_gadget_generic_cmd(cmd, param);
210
211         dwc3_writel(dwc->regs, DWC3_DGCMDPAR, param);
212         dwc3_writel(dwc->regs, DWC3_DGCMD, cmd | DWC3_DGCMD_CMDACT);
213
214         do {
215                 reg = dwc3_readl(dwc->regs, DWC3_DGCMD);
216                 if (!(reg & DWC3_DGCMD_CMDACT)) {
217                         dwc3_trace(trace_dwc3_gadget,
218                                         "Command Complete --> %d",
219                                         DWC3_DGCMD_STATUS(reg));
220                         if (DWC3_DGCMD_STATUS(reg))
221                                 return -EINVAL;
222                         return 0;
223                 }
224
225                 /*
226                  * We can't sleep here, because it's also called from
227                  * interrupt context.
228                  */
229                 timeout--;
230                 if (!timeout) {
231                         dwc3_trace(trace_dwc3_gadget,
232                                         "Command Timed Out");
233                         return -ETIMEDOUT;
234                 }
235                 udelay(1);
236         } while (1);
237 }
238
239 static int __dwc3_gadget_wakeup(struct dwc3 *dwc);
240
241 int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned cmd,
242                 struct dwc3_gadget_ep_cmd_params *params)
243 {
244         struct dwc3             *dwc = dep->dwc;
245         u32                     timeout = 500;
246         u32                     reg;
247
248         int                     susphy = false;
249         int                     ret = -EINVAL;
250
251         unsigned                ep = dep->number;
252
253         trace_dwc3_gadget_ep_cmd(dep, cmd, params);
254
255         /*
256          * Synopsys Databook 2.60a states, on section 6.3.2.5.[1-8], that if
257          * we're issuing an endpoint command, we must check if
258          * GUSB2PHYCFG.SUSPHY bit is set. If it is, then we need to clear it.
259          *
260          * We will also set SUSPHY bit to what it was before returning as stated
261          * by the same section on Synopsys databook.
262          */
263         reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
264         if (unlikely(reg & DWC3_GUSB2PHYCFG_SUSPHY)) {
265                 susphy = true;
266                 reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
267                 dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
268         }
269
270         if (cmd == DWC3_DEPCMD_STARTTRANSFER) {
271                 int             needs_wakeup;
272
273                 needs_wakeup = (dwc->link_state == DWC3_LINK_STATE_U1 ||
274                                 dwc->link_state == DWC3_LINK_STATE_U2 ||
275                                 dwc->link_state == DWC3_LINK_STATE_U3);
276
277                 if (unlikely(needs_wakeup)) {
278                         ret = __dwc3_gadget_wakeup(dwc);
279                         dev_WARN_ONCE(dwc->dev, ret, "wakeup failed --> %d\n",
280                                         ret);
281                 }
282         }
283
284         dwc3_writel(dwc->regs, DWC3_DEPCMDPAR0(ep), params->param0);
285         dwc3_writel(dwc->regs, DWC3_DEPCMDPAR1(ep), params->param1);
286         dwc3_writel(dwc->regs, DWC3_DEPCMDPAR2(ep), params->param2);
287
288         dwc3_writel(dwc->regs, DWC3_DEPCMD(ep), cmd | DWC3_DEPCMD_CMDACT);
289         do {
290                 reg = dwc3_readl(dwc->regs, DWC3_DEPCMD(ep));
291                 if (!(reg & DWC3_DEPCMD_CMDACT)) {
292                         int cmd_status = DWC3_DEPCMD_STATUS(reg);
293
294                         dwc3_trace(trace_dwc3_gadget,
295                                         "Command Complete --> %d",
296                                         cmd_status);
297
298                         switch (cmd_status) {
299                         case 0:
300                                 ret = 0;
301                                 break;
302                         case DEPEVT_TRANSFER_NO_RESOURCE:
303                                 dwc3_trace(trace_dwc3_gadget, "%s: no resource available");
304                                 ret = -EINVAL;
305                                 break;
306                         case DEPEVT_TRANSFER_BUS_EXPIRY:
307                                 /*
308                                  * SW issues START TRANSFER command to
309                                  * isochronous ep with future frame interval. If
310                                  * future interval time has already passed when
311                                  * core receives the command, it will respond
312                                  * with an error status of 'Bus Expiry'.
313                                  *
314                                  * Instead of always returning -EINVAL, let's
315                                  * give a hint to the gadget driver that this is
316                                  * the case by returning -EAGAIN.
317                                  */
318                                 dwc3_trace(trace_dwc3_gadget, "%s: bus expiry");
319                                 ret = -EAGAIN;
320                                 break;
321                         default:
322                                 dev_WARN(dwc->dev, "UNKNOWN cmd status\n");
323                         }
324
325                         break;
326                 }
327
328                 /*
329                  * We can't sleep here, because it is also called from
330                  * interrupt context.
331                  */
332                 timeout--;
333                 if (!timeout) {
334                         dwc3_trace(trace_dwc3_gadget,
335                                         "Command Timed Out");
336                         ret = -ETIMEDOUT;
337                         break;
338                 }
339         } while (1);
340
341         if (unlikely(susphy)) {
342                 reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
343                 reg |= DWC3_GUSB2PHYCFG_SUSPHY;
344                 dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
345         }
346
347         return ret;
348 }
349
350 static int dwc3_send_clear_stall_ep_cmd(struct dwc3_ep *dep)
351 {
352         struct dwc3 *dwc = dep->dwc;
353         struct dwc3_gadget_ep_cmd_params params;
354         u32 cmd = DWC3_DEPCMD_CLEARSTALL;
355
356         /*
357          * As of core revision 2.60a the recommended programming model
358          * is to set the ClearPendIN bit when issuing a Clear Stall EP
359          * command for IN endpoints. This is to prevent an issue where
360          * some (non-compliant) hosts may not send ACK TPs for pending
361          * IN transfers due to a mishandled error condition. Synopsys
362          * STAR 9000614252.
363          */
364         if (dep->direction && (dwc->revision >= DWC3_REVISION_260A))
365                 cmd |= DWC3_DEPCMD_CLEARPENDIN;
366
367         memset(&params, 0, sizeof(params));
368
369         return dwc3_send_gadget_ep_cmd(dep, cmd, &params);
370 }
371
372 static dma_addr_t dwc3_trb_dma_offset(struct dwc3_ep *dep,
373                 struct dwc3_trb *trb)
374 {
375         u32             offset = (char *) trb - (char *) dep->trb_pool;
376
377         return dep->trb_pool_dma + offset;
378 }
379
380 static int dwc3_alloc_trb_pool(struct dwc3_ep *dep)
381 {
382         struct dwc3             *dwc = dep->dwc;
383
384         if (dep->trb_pool)
385                 return 0;
386
387         dep->trb_pool = dma_alloc_coherent(dwc->dev,
388                         sizeof(struct dwc3_trb) * DWC3_TRB_NUM,
389                         &dep->trb_pool_dma, GFP_KERNEL);
390         if (!dep->trb_pool) {
391                 dev_err(dep->dwc->dev, "failed to allocate trb pool for %s\n",
392                                 dep->name);
393                 return -ENOMEM;
394         }
395
396         return 0;
397 }
398
399 static void dwc3_free_trb_pool(struct dwc3_ep *dep)
400 {
401         struct dwc3             *dwc = dep->dwc;
402
403         dma_free_coherent(dwc->dev, sizeof(struct dwc3_trb) * DWC3_TRB_NUM,
404                         dep->trb_pool, dep->trb_pool_dma);
405
406         dep->trb_pool = NULL;
407         dep->trb_pool_dma = 0;
408 }
409
410 static int dwc3_gadget_set_xfer_resource(struct dwc3 *dwc, struct dwc3_ep *dep);
411
412 /**
413  * dwc3_gadget_start_config - Configure EP resources
414  * @dwc: pointer to our controller context structure
415  * @dep: endpoint that is being enabled
416  *
417  * The assignment of transfer resources cannot perfectly follow the
418  * data book due to the fact that the controller driver does not have
419  * all knowledge of the configuration in advance. It is given this
420  * information piecemeal by the composite gadget framework after every
421  * SET_CONFIGURATION and SET_INTERFACE. Trying to follow the databook
422  * programming model in this scenario can cause errors. For two
423  * reasons:
424  *
425  * 1) The databook says to do DEPSTARTCFG for every SET_CONFIGURATION
426  * and SET_INTERFACE (8.1.5). This is incorrect in the scenario of
427  * multiple interfaces.
428  *
429  * 2) The databook does not mention doing more DEPXFERCFG for new
430  * endpoint on alt setting (8.1.6).
431  *
432  * The following simplified method is used instead:
433  *
434  * All hardware endpoints can be assigned a transfer resource and this
435  * setting will stay persistent until either a core reset or
436  * hibernation. So whenever we do a DEPSTARTCFG(0) we can go ahead and
437  * do DEPXFERCFG for every hardware endpoint as well. We are
438  * guaranteed that there are as many transfer resources as endpoints.
439  *
440  * This function is called for each endpoint when it is being enabled
441  * but is triggered only when called for EP0-out, which always happens
442  * first, and which should only happen in one of the above conditions.
443  */
444 static int dwc3_gadget_start_config(struct dwc3 *dwc, struct dwc3_ep *dep)
445 {
446         struct dwc3_gadget_ep_cmd_params params;
447         u32                     cmd;
448         int                     i;
449         int                     ret;
450
451         if (dep->number)
452                 return 0;
453
454         memset(&params, 0x00, sizeof(params));
455         cmd = DWC3_DEPCMD_DEPSTARTCFG;
456
457         ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
458         if (ret)
459                 return ret;
460
461         for (i = 0; i < DWC3_ENDPOINTS_NUM; i++) {
462                 struct dwc3_ep *dep = dwc->eps[i];
463
464                 if (!dep)
465                         continue;
466
467                 ret = dwc3_gadget_set_xfer_resource(dwc, dep);
468                 if (ret)
469                         return ret;
470         }
471
472         return 0;
473 }
474
475 static int dwc3_gadget_set_ep_config(struct dwc3 *dwc, struct dwc3_ep *dep,
476                 const struct usb_endpoint_descriptor *desc,
477                 const struct usb_ss_ep_comp_descriptor *comp_desc,
478                 bool ignore, bool restore)
479 {
480         struct dwc3_gadget_ep_cmd_params params;
481
482         memset(&params, 0x00, sizeof(params));
483
484         params.param0 = DWC3_DEPCFG_EP_TYPE(usb_endpoint_type(desc))
485                 | DWC3_DEPCFG_MAX_PACKET_SIZE(usb_endpoint_maxp(desc));
486
487         /* Burst size is only needed in SuperSpeed mode */
488         if (dwc->gadget.speed >= USB_SPEED_SUPER) {
489                 u32 burst = dep->endpoint.maxburst;
490                 params.param0 |= DWC3_DEPCFG_BURST_SIZE(burst - 1);
491         }
492
493         if (ignore)
494                 params.param0 |= DWC3_DEPCFG_IGN_SEQ_NUM;
495
496         if (restore) {
497                 params.param0 |= DWC3_DEPCFG_ACTION_RESTORE;
498                 params.param2 |= dep->saved_state;
499         }
500
501         params.param1 = DWC3_DEPCFG_XFER_COMPLETE_EN
502                 | DWC3_DEPCFG_XFER_NOT_READY_EN;
503
504         if (usb_ss_max_streams(comp_desc) && usb_endpoint_xfer_bulk(desc)) {
505                 params.param1 |= DWC3_DEPCFG_STREAM_CAPABLE
506                         | DWC3_DEPCFG_STREAM_EVENT_EN;
507                 dep->stream_capable = true;
508         }
509
510         if (!usb_endpoint_xfer_control(desc))
511                 params.param1 |= DWC3_DEPCFG_XFER_IN_PROGRESS_EN;
512
513         /*
514          * We are doing 1:1 mapping for endpoints, meaning
515          * Physical Endpoints 2 maps to Logical Endpoint 2 and
516          * so on. We consider the direction bit as part of the physical
517          * endpoint number. So USB endpoint 0x81 is 0x03.
518          */
519         params.param1 |= DWC3_DEPCFG_EP_NUMBER(dep->number);
520
521         /*
522          * We must use the lower 16 TX FIFOs even though
523          * HW might have more
524          */
525         if (dep->direction)
526                 params.param0 |= DWC3_DEPCFG_FIFO_NUMBER(dep->number >> 1);
527
528         if (desc->bInterval) {
529                 params.param1 |= DWC3_DEPCFG_BINTERVAL_M1(desc->bInterval - 1);
530                 dep->interval = 1 << (desc->bInterval - 1);
531         }
532
533         return dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETEPCONFIG, &params);
534 }
535
536 static int dwc3_gadget_set_xfer_resource(struct dwc3 *dwc, struct dwc3_ep *dep)
537 {
538         struct dwc3_gadget_ep_cmd_params params;
539
540         memset(&params, 0x00, sizeof(params));
541
542         params.param0 = DWC3_DEPXFERCFG_NUM_XFER_RES(1);
543
544         return dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETTRANSFRESOURCE,
545                         &params);
546 }
547
548 /**
549  * __dwc3_gadget_ep_enable - Initializes a HW endpoint
550  * @dep: endpoint to be initialized
551  * @desc: USB Endpoint Descriptor
552  *
553  * Caller should take care of locking
554  */
555 static int __dwc3_gadget_ep_enable(struct dwc3_ep *dep,
556                 const struct usb_endpoint_descriptor *desc,
557                 const struct usb_ss_ep_comp_descriptor *comp_desc,
558                 bool ignore, bool restore)
559 {
560         struct dwc3             *dwc = dep->dwc;
561         u32                     reg;
562         int                     ret;
563
564         dwc3_trace(trace_dwc3_gadget, "Enabling %s", dep->name);
565
566         if (!(dep->flags & DWC3_EP_ENABLED)) {
567                 ret = dwc3_gadget_start_config(dwc, dep);
568                 if (ret)
569                         return ret;
570         }
571
572         ret = dwc3_gadget_set_ep_config(dwc, dep, desc, comp_desc, ignore,
573                         restore);
574         if (ret)
575                 return ret;
576
577         if (!(dep->flags & DWC3_EP_ENABLED)) {
578                 struct dwc3_trb *trb_st_hw;
579                 struct dwc3_trb *trb_link;
580
581                 dep->endpoint.desc = desc;
582                 dep->comp_desc = comp_desc;
583                 dep->type = usb_endpoint_type(desc);
584                 dep->flags |= DWC3_EP_ENABLED;
585
586                 reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
587                 reg |= DWC3_DALEPENA_EP(dep->number);
588                 dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);
589
590                 if (usb_endpoint_xfer_control(desc))
591                         goto out;
592
593                 /* Link TRB. The HWO bit is never reset */
594                 trb_st_hw = &dep->trb_pool[0];
595
596                 trb_link = &dep->trb_pool[DWC3_TRB_NUM - 1];
597                 memset(trb_link, 0, sizeof(*trb_link));
598
599                 trb_link->bpl = lower_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
600                 trb_link->bph = upper_32_bits(dwc3_trb_dma_offset(dep, trb_st_hw));
601                 trb_link->ctrl |= DWC3_TRBCTL_LINK_TRB;
602                 trb_link->ctrl |= DWC3_TRB_CTRL_HWO;
603         }
604
605 out:
606         switch (usb_endpoint_type(desc)) {
607         case USB_ENDPOINT_XFER_CONTROL:
608                 /* don't change name */
609                 break;
610         case USB_ENDPOINT_XFER_ISOC:
611                 strlcat(dep->name, "-isoc", sizeof(dep->name));
612                 break;
613         case USB_ENDPOINT_XFER_BULK:
614                 strlcat(dep->name, "-bulk", sizeof(dep->name));
615                 break;
616         case USB_ENDPOINT_XFER_INT:
617                 strlcat(dep->name, "-int", sizeof(dep->name));
618                 break;
619         default:
620                 dev_err(dwc->dev, "invalid endpoint transfer type\n");
621         }
622
623         return 0;
624 }
625
626 static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum, bool force);
627 static void dwc3_remove_requests(struct dwc3 *dwc, struct dwc3_ep *dep)
628 {
629         struct dwc3_request             *req;
630
631         if (!list_empty(&dep->started_list)) {
632                 dwc3_stop_active_transfer(dwc, dep->number, true);
633
634                 /* - giveback all requests to gadget driver */
635                 while (!list_empty(&dep->started_list)) {
636                         req = next_request(&dep->started_list);
637
638                         dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
639                 }
640         }
641
642         while (!list_empty(&dep->pending_list)) {
643                 req = next_request(&dep->pending_list);
644
645                 dwc3_gadget_giveback(dep, req, -ESHUTDOWN);
646         }
647 }
648
649 /**
650  * __dwc3_gadget_ep_disable - Disables a HW endpoint
651  * @dep: the endpoint to disable
652  *
653  * This function also removes requests which are currently processed ny the
654  * hardware and those which are not yet scheduled.
655  * Caller should take care of locking.
656  */
657 static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
658 {
659         struct dwc3             *dwc = dep->dwc;
660         u32                     reg;
661
662         dwc3_trace(trace_dwc3_gadget, "Disabling %s", dep->name);
663
664         dwc3_remove_requests(dwc, dep);
665
666         /* make sure HW endpoint isn't stalled */
667         if (dep->flags & DWC3_EP_STALL)
668                 __dwc3_gadget_ep_set_halt(dep, 0, false);
669
670         reg = dwc3_readl(dwc->regs, DWC3_DALEPENA);
671         reg &= ~DWC3_DALEPENA_EP(dep->number);
672         dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);
673
674         dep->stream_capable = false;
675         dep->endpoint.desc = NULL;
676         dep->comp_desc = NULL;
677         dep->type = 0;
678         dep->flags = 0;
679
680         snprintf(dep->name, sizeof(dep->name), "ep%d%s",
681                         dep->number >> 1,
682                         (dep->number & 1) ? "in" : "out");
683
684         return 0;
685 }
686
687 /* -------------------------------------------------------------------------- */
688
689 static int dwc3_gadget_ep0_enable(struct usb_ep *ep,
690                 const struct usb_endpoint_descriptor *desc)
691 {
692         return -EINVAL;
693 }
694
695 static int dwc3_gadget_ep0_disable(struct usb_ep *ep)
696 {
697         return -EINVAL;
698 }
699
700 /* -------------------------------------------------------------------------- */
701
702 static int dwc3_gadget_ep_enable(struct usb_ep *ep,
703                 const struct usb_endpoint_descriptor *desc)
704 {
705         struct dwc3_ep                  *dep;
706         struct dwc3                     *dwc;
707         unsigned long                   flags;
708         int                             ret;
709
710         if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
711                 pr_debug("dwc3: invalid parameters\n");
712                 return -EINVAL;
713         }
714
715         if (!desc->wMaxPacketSize) {
716                 pr_debug("dwc3: missing wMaxPacketSize\n");
717                 return -EINVAL;
718         }
719
720         dep = to_dwc3_ep(ep);
721         dwc = dep->dwc;
722
723         if (dev_WARN_ONCE(dwc->dev, dep->flags & DWC3_EP_ENABLED,
724                                         "%s is already enabled\n",
725                                         dep->name))
726                 return 0;
727
728         spin_lock_irqsave(&dwc->lock, flags);
729         ret = __dwc3_gadget_ep_enable(dep, desc, ep->comp_desc, false, false);
730         spin_unlock_irqrestore(&dwc->lock, flags);
731
732         return ret;
733 }
734
735 static int dwc3_gadget_ep_disable(struct usb_ep *ep)
736 {
737         struct dwc3_ep                  *dep;
738         struct dwc3                     *dwc;
739         unsigned long                   flags;
740         int                             ret;
741
742         if (!ep) {
743                 pr_debug("dwc3: invalid parameters\n");
744                 return -EINVAL;
745         }
746
747         dep = to_dwc3_ep(ep);
748         dwc = dep->dwc;
749
750         if (dev_WARN_ONCE(dwc->dev, !(dep->flags & DWC3_EP_ENABLED),
751                                         "%s is already disabled\n",
752                                         dep->name))
753                 return 0;
754
755         spin_lock_irqsave(&dwc->lock, flags);
756         ret = __dwc3_gadget_ep_disable(dep);
757         spin_unlock_irqrestore(&dwc->lock, flags);
758
759         return ret;
760 }
761
762 static struct usb_request *dwc3_gadget_ep_alloc_request(struct usb_ep *ep,
763         gfp_t gfp_flags)
764 {
765         struct dwc3_request             *req;
766         struct dwc3_ep                  *dep = to_dwc3_ep(ep);
767
768         req = kzalloc(sizeof(*req), gfp_flags);
769         if (!req)
770                 return NULL;
771
772         req->epnum      = dep->number;
773         req->dep        = dep;
774
775         trace_dwc3_alloc_request(req);
776
777         return &req->request;
778 }
779
780 static void dwc3_gadget_ep_free_request(struct usb_ep *ep,
781                 struct usb_request *request)
782 {
783         struct dwc3_request             *req = to_dwc3_request(request);
784
785         trace_dwc3_free_request(req);
786         kfree(req);
787 }
788
789 /**
790  * dwc3_prepare_one_trb - setup one TRB from one request
791  * @dep: endpoint for which this request is prepared
792  * @req: dwc3_request pointer
793  */
794 static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
795                 struct dwc3_request *req, dma_addr_t dma,
796                 unsigned length, unsigned last, unsigned chain, unsigned node)
797 {
798         struct dwc3_trb         *trb;
799
800         dwc3_trace(trace_dwc3_gadget, "%s: req %p dma %08llx length %d%s%s",
801                         dep->name, req, (unsigned long long) dma,
802                         length, last ? " last" : "",
803                         chain ? " chain" : "");
804
805
806         trb = &dep->trb_pool[dep->trb_enqueue];
807
808         if (!req->trb) {
809                 dwc3_gadget_move_started_request(req);
810                 req->trb = trb;
811                 req->trb_dma = dwc3_trb_dma_offset(dep, trb);
812                 req->first_trb_index = dep->trb_enqueue;
813         }
814
815         dwc3_ep_inc_enq(dep);
816         /* Skip the LINK-TRB */
817         if (dwc3_ep_is_last_trb(dep->trb_enqueue))
818                 dwc3_ep_inc_enq(dep);
819
820         trb->size = DWC3_TRB_SIZE_LENGTH(length);
821         trb->bpl = lower_32_bits(dma);
822         trb->bph = upper_32_bits(dma);
823
824         switch (usb_endpoint_type(dep->endpoint.desc)) {
825         case USB_ENDPOINT_XFER_CONTROL:
826                 trb->ctrl = DWC3_TRBCTL_CONTROL_SETUP;
827                 break;
828
829         case USB_ENDPOINT_XFER_ISOC:
830                 if (!node)
831                         trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS_FIRST;
832                 else
833                         trb->ctrl = DWC3_TRBCTL_ISOCHRONOUS;
834
835                 /* always enable Interrupt on Missed ISOC */
836                 trb->ctrl |= DWC3_TRB_CTRL_ISP_IMI;
837                 break;
838
839         case USB_ENDPOINT_XFER_BULK:
840         case USB_ENDPOINT_XFER_INT:
841                 trb->ctrl = DWC3_TRBCTL_NORMAL;
842                 break;
843         default:
844                 /*
845                  * This is only possible with faulty memory because we
846                  * checked it already :)
847                  */
848                 BUG();
849         }
850
851         /* always enable Continue on Short Packet */
852         trb->ctrl |= DWC3_TRB_CTRL_CSP;
853
854         if (!req->request.no_interrupt && !chain)
855                 trb->ctrl |= DWC3_TRB_CTRL_IOC | DWC3_TRB_CTRL_ISP_IMI;
856
857         if (last)
858                 trb->ctrl |= DWC3_TRB_CTRL_LST;
859
860         if (chain)
861                 trb->ctrl |= DWC3_TRB_CTRL_CHN;
862
863         if (usb_endpoint_xfer_bulk(dep->endpoint.desc) && dep->stream_capable)
864                 trb->ctrl |= DWC3_TRB_CTRL_SID_SOFN(req->request.stream_id);
865
866         trb->ctrl |= DWC3_TRB_CTRL_HWO;
867
868         trace_dwc3_prepare_trb(dep, trb);
869 }
870
871 static u32 dwc3_calc_trbs_left(struct dwc3_ep *dep)
872 {
873         struct dwc3_trb         *tmp;
874
875         /*
876          * If enqueue & dequeue are equal than it is either full or empty.
877          *
878          * One way to know for sure is if the TRB right before us has HWO bit
879          * set or not. If it has, then we're definitely full and can't fit any
880          * more transfers in our ring.
881          */
882         if (dep->trb_enqueue == dep->trb_dequeue) {
883                 /* If we're full, enqueue/dequeue are > 0 */
884                 if (dep->trb_enqueue) {
885                         tmp = &dep->trb_pool[dep->trb_enqueue - 1];
886                         if (tmp->ctrl & DWC3_TRB_CTRL_HWO)
887                                 return 0;
888                 }
889
890                 return DWC3_TRB_NUM - 1;
891         }
892
893         return dep->trb_dequeue - dep->trb_enqueue;
894 }
895
896 static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
897                 struct dwc3_request *req, unsigned int trbs_left)
898 {
899         struct usb_request *request = &req->request;
900         struct scatterlist *sg = request->sg;
901         struct scatterlist *s;
902         unsigned int    last = false;
903         unsigned int    length;
904         dma_addr_t      dma;
905         int             i;
906
907         for_each_sg(sg, s, request->num_mapped_sgs, i) {
908                 unsigned chain = true;
909
910                 length = sg_dma_len(s);
911                 dma = sg_dma_address(s);
912
913                 if (sg_is_last(s)) {
914                         if (list_is_last(&req->list, &dep->pending_list))
915                                 last = true;
916
917                         chain = false;
918                 }
919
920                 if (!trbs_left)
921                         last = true;
922
923                 if (last)
924                         chain = false;
925
926                 dwc3_prepare_one_trb(dep, req, dma, length,
927                                 last, chain, i);
928
929                 if (last)
930                         break;
931         }
932 }
933
934 static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
935                 struct dwc3_request *req, unsigned int trbs_left)
936 {
937         unsigned int    last = false;
938         unsigned int    length;
939         dma_addr_t      dma;
940
941         dma = req->request.dma;
942         length = req->request.length;
943
944         if (!trbs_left)
945                 last = true;
946
947         /* Is this the last request? */
948         if (list_is_last(&req->list, &dep->pending_list))
949                 last = true;
950
951         dwc3_prepare_one_trb(dep, req, dma, length,
952                         last, false, 0);
953 }
954
955 /*
956  * dwc3_prepare_trbs - setup TRBs from requests
957  * @dep: endpoint for which requests are being prepared
958  *
959  * The function goes through the requests list and sets up TRBs for the
960  * transfers. The function returns once there are no more TRBs available or
961  * it runs out of requests.
962  */
963 static void dwc3_prepare_trbs(struct dwc3_ep *dep)
964 {
965         struct dwc3_request     *req, *n;
966         u32                     trbs_left;
967
968         BUILD_BUG_ON_NOT_POWER_OF_2(DWC3_TRB_NUM);
969
970         trbs_left = dwc3_calc_trbs_left(dep);
971
972         list_for_each_entry_safe(req, n, &dep->pending_list, list) {
973                 if (req->request.num_mapped_sgs > 0)
974                         dwc3_prepare_one_trb_sg(dep, req, trbs_left--);
975                 else
976                         dwc3_prepare_one_trb_linear(dep, req, trbs_left--);
977
978                 if (!trbs_left)
979                         return;
980         }
981 }
982
983 static int __dwc3_gadget_kick_transfer(struct dwc3_ep *dep, u16 cmd_param)
984 {
985         struct dwc3_gadget_ep_cmd_params params;
986         struct dwc3_request             *req;
987         struct dwc3                     *dwc = dep->dwc;
988         int                             starting;
989         int                             ret;
990         u32                             cmd;
991
992         starting = !(dep->flags & DWC3_EP_BUSY);
993
994         dwc3_prepare_trbs(dep);
995         req = next_request(&dep->started_list);
996         if (!req) {
997                 dep->flags |= DWC3_EP_PENDING_REQUEST;
998                 return 0;
999         }
1000
1001         memset(&params, 0, sizeof(params));
1002
1003         if (starting) {
1004                 params.param0 = upper_32_bits(req->trb_dma);
1005                 params.param1 = lower_32_bits(req->trb_dma);
1006                 cmd = DWC3_DEPCMD_STARTTRANSFER;
1007         } else {
1008                 cmd = DWC3_DEPCMD_UPDATETRANSFER;
1009         }
1010
1011         cmd |= DWC3_DEPCMD_PARAM(cmd_param);
1012         ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
1013         if (ret < 0) {
1014                 /*
1015                  * FIXME we need to iterate over the list of requests
1016                  * here and stop, unmap, free and del each of the linked
1017                  * requests instead of what we do now.
1018                  */
1019                 usb_gadget_unmap_request(&dwc->gadget, &req->request,
1020                                 req->direction);
1021                 list_del(&req->list);
1022                 return ret;
1023         }
1024
1025         dep->flags |= DWC3_EP_BUSY;
1026
1027         if (starting) {
1028                 dep->resource_index = dwc3_gadget_ep_get_transfer_index(dwc,
1029                                 dep->number);
1030                 WARN_ON_ONCE(!dep->resource_index);
1031         }
1032
1033         return 0;
1034 }
1035
1036 static void __dwc3_gadget_start_isoc(struct dwc3 *dwc,
1037                 struct dwc3_ep *dep, u32 cur_uf)
1038 {
1039         u32 uf;
1040
1041         if (list_empty(&dep->pending_list)) {
1042                 dwc3_trace(trace_dwc3_gadget,
1043                                 "ISOC ep %s run out for requests",
1044                                 dep->name);
1045                 dep->flags |= DWC3_EP_PENDING_REQUEST;
1046                 return;
1047         }
1048
1049         /* 4 micro frames in the future */
1050         uf = cur_uf + dep->interval * 4;
1051
1052         __dwc3_gadget_kick_transfer(dep, uf);
1053 }
1054
1055 static void dwc3_gadget_start_isoc(struct dwc3 *dwc,
1056                 struct dwc3_ep *dep, const struct dwc3_event_depevt *event)
1057 {
1058         u32 cur_uf, mask;
1059
1060         mask = ~(dep->interval - 1);
1061         cur_uf = event->parameters & mask;
1062
1063         __dwc3_gadget_start_isoc(dwc, dep, cur_uf);
1064 }
1065
1066 static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
1067 {
1068         struct dwc3             *dwc = dep->dwc;
1069         int                     ret;
1070
1071         if (!dep->endpoint.desc) {
1072                 dwc3_trace(trace_dwc3_gadget,
1073                                 "trying to queue request %p to disabled %s\n",
1074                                 &req->request, dep->endpoint.name);
1075                 return -ESHUTDOWN;
1076         }
1077
1078         if (WARN(req->dep != dep, "request %p belongs to '%s'\n",
1079                                 &req->request, req->dep->name)) {
1080                 dwc3_trace(trace_dwc3_gadget, "request %p belongs to '%s'\n",
1081                                 &req->request, req->dep->name);
1082                 return -EINVAL;
1083         }
1084
1085         req->request.actual     = 0;
1086         req->request.status     = -EINPROGRESS;
1087         req->direction          = dep->direction;
1088         req->epnum              = dep->number;
1089
1090         trace_dwc3_ep_queue(req);
1091
1092         /*
1093          * Per databook, the total size of buffer must be a multiple
1094          * of MaxPacketSize for OUT endpoints. And MaxPacketSize is
1095          * configed for endpoints in dwc3_gadget_set_ep_config(),
1096          * set to usb_endpoint_descriptor->wMaxPacketSize.
1097          */
1098         if (dep->direction == 0 &&
1099             req->request.length % dep->endpoint.desc->wMaxPacketSize)
1100                 req->request.length = roundup(req->request.length,
1101                                         dep->endpoint.desc->wMaxPacketSize);
1102
1103         /*
1104          * We only add to our list of requests now and
1105          * start consuming the list once we get XferNotReady
1106          * IRQ.
1107          *
1108          * That way, we avoid doing anything that we don't need
1109          * to do now and defer it until the point we receive a
1110          * particular token from the Host side.
1111          *
1112          * This will also avoid Host cancelling URBs due to too
1113          * many NAKs.
1114          */
1115         ret = usb_gadget_map_request(&dwc->gadget, &req->request,
1116                         dep->direction);
1117         if (ret)
1118                 return ret;
1119
1120         list_add_tail(&req->list, &dep->pending_list);
1121
1122         /*
1123          * If there are no pending requests and the endpoint isn't already
1124          * busy, we will just start the request straight away.
1125          *
1126          * This will save one IRQ (XFER_NOT_READY) and possibly make it a
1127          * little bit faster.
1128          */
1129         if (!usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
1130                         !usb_endpoint_xfer_int(dep->endpoint.desc) &&
1131                         !(dep->flags & DWC3_EP_BUSY)) {
1132                 ret = __dwc3_gadget_kick_transfer(dep, 0);
1133                 goto out;
1134         }
1135
1136         /*
1137          * There are a few special cases:
1138          *
1139          * 1. XferNotReady with empty list of requests. We need to kick the
1140          *    transfer here in that situation, otherwise we will be NAKing
1141          *    forever. If we get XferNotReady before gadget driver has a
1142          *    chance to queue a request, we will ACK the IRQ but won't be
1143          *    able to receive the data until the next request is queued.
1144          *    The following code is handling exactly that.
1145          *
1146          */
1147         if (dep->flags & DWC3_EP_PENDING_REQUEST) {
1148                 /*
1149                  * If xfernotready is already elapsed and it is a case
1150                  * of isoc transfer, then issue END TRANSFER, so that
1151                  * you can receive xfernotready again and can have
1152                  * notion of current microframe.
1153                  */
1154                 if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
1155                         if (list_empty(&dep->started_list)) {
1156                                 dwc3_stop_active_transfer(dwc, dep->number, true);
1157                                 dep->flags = DWC3_EP_ENABLED;
1158                         }
1159                         return 0;
1160                 }
1161
1162                 ret = __dwc3_gadget_kick_transfer(dep, 0);
1163                 if (!ret)
1164                         dep->flags &= ~DWC3_EP_PENDING_REQUEST;
1165
1166                 goto out;
1167         }
1168
1169         /*
1170          * 2. XferInProgress on Isoc EP with an active transfer. We need to
1171          *    kick the transfer here after queuing a request, otherwise the
1172          *    core may not see the modified TRB(s).
1173          */
1174         if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
1175                         (dep->flags & DWC3_EP_BUSY) &&
1176                         !(dep->flags & DWC3_EP_MISSED_ISOC)) {
1177                 WARN_ON_ONCE(!dep->resource_index);
1178                 ret = __dwc3_gadget_kick_transfer(dep, dep->resource_index);
1179                 goto out;
1180         }
1181
1182         /*
1183          * 4. Stream Capable Bulk Endpoints. We need to start the transfer
1184          * right away, otherwise host will not know we have streams to be
1185          * handled.
1186          */
1187         if (dep->stream_capable)
1188                 ret = __dwc3_gadget_kick_transfer(dep, 0);
1189
1190 out:
1191         if (ret && ret != -EBUSY)
1192                 dwc3_trace(trace_dwc3_gadget,
1193                                 "%s: failed to kick transfers\n",
1194                                 dep->name);
1195         if (ret == -EBUSY)
1196                 ret = 0;
1197
1198         return ret;
1199 }
1200
1201 static void __dwc3_gadget_ep_zlp_complete(struct usb_ep *ep,
1202                 struct usb_request *request)
1203 {
1204         dwc3_gadget_ep_free_request(ep, request);
1205 }
1206
1207 static int __dwc3_gadget_ep_queue_zlp(struct dwc3 *dwc, struct dwc3_ep *dep)
1208 {
1209         struct dwc3_request             *req;
1210         struct usb_request              *request;
1211         struct usb_ep                   *ep = &dep->endpoint;
1212
1213         dwc3_trace(trace_dwc3_gadget, "queueing ZLP\n");
1214         request = dwc3_gadget_ep_alloc_request(ep, GFP_ATOMIC);
1215         if (!request)
1216                 return -ENOMEM;
1217
1218         request->length = 0;
1219         request->buf = dwc->zlp_buf;
1220         request->complete = __dwc3_gadget_ep_zlp_complete;
1221
1222         req = to_dwc3_request(request);
1223
1224         return __dwc3_gadget_ep_queue(dep, req);
1225 }
1226
1227 static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,
1228         gfp_t gfp_flags)
1229 {
1230         struct dwc3_request             *req = to_dwc3_request(request);
1231         struct dwc3_ep                  *dep = to_dwc3_ep(ep);
1232         struct dwc3                     *dwc = dep->dwc;
1233
1234         unsigned long                   flags;
1235
1236         int                             ret;
1237
1238         spin_lock_irqsave(&dwc->lock, flags);
1239         ret = __dwc3_gadget_ep_queue(dep, req);
1240
1241         /*
1242          * Okay, here's the thing, if gadget driver has requested for a ZLP by
1243          * setting request->zero, instead of doing magic, we will just queue an
1244          * extra usb_request ourselves so that it gets handled the same way as
1245          * any other request.
1246          */
1247         if (ret == 0 && request->zero && request->length &&
1248             (request->length % ep->desc->wMaxPacketSize == 0))
1249                 ret = __dwc3_gadget_ep_queue_zlp(dwc, dep);
1250
1251         spin_unlock_irqrestore(&dwc->lock, flags);
1252
1253         return ret;
1254 }
1255
1256 static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
1257                 struct usb_request *request)
1258 {
1259         struct dwc3_request             *req = to_dwc3_request(request);
1260         struct dwc3_request             *r = NULL;
1261
1262         struct dwc3_ep                  *dep = to_dwc3_ep(ep);
1263         struct dwc3                     *dwc = dep->dwc;
1264
1265         unsigned long                   flags;
1266         int                             ret = 0;
1267
1268         trace_dwc3_ep_dequeue(req);
1269
1270         spin_lock_irqsave(&dwc->lock, flags);
1271
1272         list_for_each_entry(r, &dep->pending_list, list) {
1273                 if (r == req)
1274                         break;
1275         }
1276
1277         if (r != req) {
1278                 list_for_each_entry(r, &dep->started_list, list) {
1279                         if (r == req)
1280                                 break;
1281                 }
1282                 if (r == req) {
1283                         /* wait until it is processed */
1284                         dwc3_stop_active_transfer(dwc, dep->number, true);
1285                         goto out1;
1286                 }
1287                 dev_err(dwc->dev, "request %p was not queued to %s\n",
1288                                 request, ep->name);
1289                 ret = -EINVAL;
1290                 goto out0;
1291         }
1292
1293 out1:
1294         /* giveback the request */
1295         dwc3_gadget_giveback(dep, req, -ECONNRESET);
1296
1297 out0:
1298         spin_unlock_irqrestore(&dwc->lock, flags);
1299
1300         return ret;
1301 }
1302
1303 int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
1304 {
1305         struct dwc3_gadget_ep_cmd_params        params;
1306         struct dwc3                             *dwc = dep->dwc;
1307         int                                     ret;
1308
1309         if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
1310                 dev_err(dwc->dev, "%s is of Isochronous type\n", dep->name);
1311                 return -EINVAL;
1312         }
1313
1314         memset(&params, 0x00, sizeof(params));
1315
1316         if (value) {
1317                 if (!protocol && ((dep->direction && dep->flags & DWC3_EP_BUSY) ||
1318                                 (!list_empty(&dep->started_list) ||
1319                                  !list_empty(&dep->pending_list)))) {
1320                         dwc3_trace(trace_dwc3_gadget,
1321                                         "%s: pending request, cannot halt",
1322                                         dep->name);
1323                         return -EAGAIN;
1324                 }
1325
1326                 ret = dwc3_send_gadget_ep_cmd(dep, DWC3_DEPCMD_SETSTALL,
1327                                 &params);
1328                 if (ret)
1329                         dev_err(dwc->dev, "failed to set STALL on %s\n",
1330                                         dep->name);
1331                 else
1332                         dep->flags |= DWC3_EP_STALL;
1333         } else {
1334
1335                 ret = dwc3_send_clear_stall_ep_cmd(dep);
1336                 if (ret)
1337                         dev_err(dwc->dev, "failed to clear STALL on %s\n",
1338                                         dep->name);
1339                 else
1340                         dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE);
1341         }
1342
1343         return ret;
1344 }
1345
1346 static int dwc3_gadget_ep_set_halt(struct usb_ep *ep, int value)
1347 {
1348         struct dwc3_ep                  *dep = to_dwc3_ep(ep);
1349         struct dwc3                     *dwc = dep->dwc;
1350
1351         unsigned long                   flags;
1352
1353         int                             ret;
1354
1355         spin_lock_irqsave(&dwc->lock, flags);
1356         ret = __dwc3_gadget_ep_set_halt(dep, value, false);
1357         spin_unlock_irqrestore(&dwc->lock, flags);
1358
1359         return ret;
1360 }
1361
1362 static int dwc3_gadget_ep_set_wedge(struct usb_ep *ep)
1363 {
1364         struct dwc3_ep                  *dep = to_dwc3_ep(ep);
1365         struct dwc3                     *dwc = dep->dwc;
1366         unsigned long                   flags;
1367         int                             ret;
1368
1369         spin_lock_irqsave(&dwc->lock, flags);
1370         dep->flags |= DWC3_EP_WEDGE;
1371
1372         if (dep->number == 0 || dep->number == 1)
1373                 ret = __dwc3_gadget_ep0_set_halt(ep, 1);
1374         else
1375                 ret = __dwc3_gadget_ep_set_halt(dep, 1, false);
1376         spin_unlock_irqrestore(&dwc->lock, flags);
1377
1378         return ret;
1379 }
1380
1381 /* -------------------------------------------------------------------------- */
1382
1383 static struct usb_endpoint_descriptor dwc3_gadget_ep0_desc = {
1384         .bLength        = USB_DT_ENDPOINT_SIZE,
1385         .bDescriptorType = USB_DT_ENDPOINT,
1386         .bmAttributes   = USB_ENDPOINT_XFER_CONTROL,
1387 };
1388
1389 static const struct usb_ep_ops dwc3_gadget_ep0_ops = {
1390         .enable         = dwc3_gadget_ep0_enable,
1391         .disable        = dwc3_gadget_ep0_disable,
1392         .alloc_request  = dwc3_gadget_ep_alloc_request,
1393         .free_request   = dwc3_gadget_ep_free_request,
1394         .queue          = dwc3_gadget_ep0_queue,
1395         .dequeue        = dwc3_gadget_ep_dequeue,
1396         .set_halt       = dwc3_gadget_ep0_set_halt,
1397         .set_wedge      = dwc3_gadget_ep_set_wedge,
1398 };
1399
1400 static const struct usb_ep_ops dwc3_gadget_ep_ops = {
1401         .enable         = dwc3_gadget_ep_enable,
1402         .disable        = dwc3_gadget_ep_disable,
1403         .alloc_request  = dwc3_gadget_ep_alloc_request,
1404         .free_request   = dwc3_gadget_ep_free_request,
1405         .queue          = dwc3_gadget_ep_queue,
1406         .dequeue        = dwc3_gadget_ep_dequeue,
1407         .set_halt       = dwc3_gadget_ep_set_halt,
1408         .set_wedge      = dwc3_gadget_ep_set_wedge,
1409 };
1410
1411 /* -------------------------------------------------------------------------- */
1412
1413 static int dwc3_gadget_get_frame(struct usb_gadget *g)
1414 {
1415         struct dwc3             *dwc = gadget_to_dwc(g);
1416         u32                     reg;
1417
1418         reg = dwc3_readl(dwc->regs, DWC3_DSTS);
1419         return DWC3_DSTS_SOFFN(reg);
1420 }
1421
1422 static int __dwc3_gadget_wakeup(struct dwc3 *dwc)
1423 {
1424         unsigned long           timeout;
1425
1426         int                     ret;
1427         u32                     reg;
1428
1429         u8                      link_state;
1430         u8                      speed;
1431
1432         /*
1433          * According to the Databook Remote wakeup request should
1434          * be issued only when the device is in early suspend state.
1435          *
1436          * We can check that via USB Link State bits in DSTS register.
1437          */
1438         reg = dwc3_readl(dwc->regs, DWC3_DSTS);
1439
1440         speed = reg & DWC3_DSTS_CONNECTSPD;
1441         if (speed == DWC3_DSTS_SUPERSPEED) {
1442                 dwc3_trace(trace_dwc3_gadget, "no wakeup on SuperSpeed\n");
1443                 return 0;
1444         }
1445
1446         link_state = DWC3_DSTS_USBLNKST(reg);
1447
1448         switch (link_state) {
1449         case DWC3_LINK_STATE_RX_DET:    /* in HS, means Early Suspend */
1450         case DWC3_LINK_STATE_U3:        /* in HS, means SUSPEND */
1451                 break;
1452         default:
1453                 dwc3_trace(trace_dwc3_gadget,
1454                                 "can't wakeup from '%s'\n",
1455                                 dwc3_gadget_link_string(link_state));
1456                 return -EINVAL;
1457         }
1458
1459         ret = dwc3_gadget_set_link_state(dwc, DWC3_LINK_STATE_RECOV);
1460         if (ret < 0) {
1461                 dev_err(dwc->dev, "failed to put link in Recovery\n");
1462                 return ret;
1463         }
1464
1465         /* Recent versions do this automatically */
1466         if (dwc->revision < DWC3_REVISION_194A) {
1467                 /* write zeroes to Link Change Request */
1468                 reg = dwc3_readl(dwc->regs, DWC3_DCTL);
1469                 reg &= ~DWC3_DCTL_ULSTCHNGREQ_MASK;
1470                 dwc3_writel(dwc->regs, DWC3_DCTL, reg);
1471         }
1472
1473         /* poll until Link State changes to ON */
1474         timeout = jiffies + msecs_to_jiffies(100);
1475
1476         while (!time_after(jiffies, timeout)) {
1477                 reg = dwc3_readl(dwc->regs, DWC3_DSTS);
1478
1479                 /* in HS, means ON */
1480                 if (DWC3_DSTS_USBLNKST(reg) == DWC3_LINK_STATE_U0)
1481                         break;
1482         }
1483
1484         if (DWC3_DSTS_USBLNKST(reg) != DWC3_LINK_STATE_U0) {
1485                 dev_err(dwc->dev, "failed to send remote wakeup\n");
1486                 return -EINVAL;
1487         }
1488
1489         return 0;
1490 }
1491
1492 static int dwc3_gadget_wakeup(struct usb_gadget *g)
1493 {
1494         struct dwc3             *dwc = gadget_to_dwc(g);
1495         unsigned long           flags;
1496         int                     ret;
1497
1498         spin_lock_irqsave(&dwc->lock, flags);
1499         ret = __dwc3_gadget_wakeup(dwc);
1500         spin_unlock_irqrestore(&dwc->lock, flags);
1501
1502         return ret;
1503 }
1504
1505 static int dwc3_gadget_set_selfpowered(struct usb_gadget *g,
1506                 int is_selfpowered)
1507 {
1508         struct dwc3             *dwc = gadget_to_dwc(g);
1509         unsigned long           flags;
1510
1511         spin_lock_irqsave(&dwc->lock, flags);
1512         g->is_selfpowered = !!is_selfpowered;
1513         spin_unlock_irqrestore(&dwc->lock, flags);
1514
1515         return 0;
1516 }
1517
1518 static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
1519 {
1520         u32                     reg;
1521         u32                     timeout = 500;
1522
1523         reg = dwc3_readl(dwc->regs, DWC3_DCTL);
1524         if (is_on) {
1525                 if (dwc->revision <= DWC3_REVISION_187A) {
1526                         reg &= ~DWC3_DCTL_TRGTULST_MASK;
1527                         reg |= DWC3_DCTL_TRGTULST_RX_DET;
1528                 }
1529
1530                 if (dwc->revision >= DWC3_REVISION_194A)
1531                         reg &= ~DWC3_DCTL_KEEP_CONNECT;
1532                 reg |= DWC3_DCTL_RUN_STOP;
1533
1534                 if (dwc->has_hibernation)
1535                         reg |= DWC3_DCTL_KEEP_CONNECT;
1536
1537                 dwc->pullups_connected = true;
1538         } else {
1539                 reg &= ~DWC3_DCTL_RUN_STOP;
1540
1541                 if (dwc->has_hibernation && !suspend)
1542                         reg &= ~DWC3_DCTL_KEEP_CONNECT;
1543
1544                 dwc->pullups_connected = false;
1545         }
1546
1547         dwc3_writel(dwc->regs, DWC3_DCTL, reg);
1548
1549         do {
1550                 reg = dwc3_readl(dwc->regs, DWC3_DSTS);
1551                 if (is_on) {
1552                         if (!(reg & DWC3_DSTS_DEVCTRLHLT))
1553                                 break;
1554                 } else {
1555                         if (reg & DWC3_DSTS_DEVCTRLHLT)
1556                                 break;
1557                 }
1558                 timeout--;
1559                 if (!timeout)
1560                         return -ETIMEDOUT;
1561                 udelay(1);
1562         } while (1);
1563
1564         dwc3_trace(trace_dwc3_gadget, "gadget %s data soft-%s",
1565                         dwc->gadget_driver
1566                         ? dwc->gadget_driver->function : "no-function",
1567                         is_on ? "connect" : "disconnect");
1568
1569         return 0;
1570 }
1571
1572 static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
1573 {
1574         struct dwc3             *dwc = gadget_to_dwc(g);
1575         unsigned long           flags;
1576         int                     ret;
1577
1578         is_on = !!is_on;
1579
1580         spin_lock_irqsave(&dwc->lock, flags);
1581         ret = dwc3_gadget_run_stop(dwc, is_on, false);
1582         spin_unlock_irqrestore(&dwc->lock, flags);
1583
1584         return ret;
1585 }
1586
1587 static void dwc3_gadget_enable_irq(struct dwc3 *dwc)
1588 {
1589         u32                     reg;
1590
1591         /* Enable all but Start and End of Frame IRQs */
1592         reg = (DWC3_DEVTEN_VNDRDEVTSTRCVEDEN |
1593                         DWC3_DEVTEN_EVNTOVERFLOWEN |
1594                         DWC3_DEVTEN_CMDCMPLTEN |
1595                         DWC3_DEVTEN_ERRTICERREN |
1596                         DWC3_DEVTEN_WKUPEVTEN |
1597                         DWC3_DEVTEN_ULSTCNGEN |
1598                         DWC3_DEVTEN_CONNECTDONEEN |
1599                         DWC3_DEVTEN_USBRSTEN |
1600                         DWC3_DEVTEN_DISCONNEVTEN);
1601
1602         dwc3_writel(dwc->regs, DWC3_DEVTEN, reg);
1603 }
1604
1605 static void dwc3_gadget_disable_irq(struct dwc3 *dwc)
1606 {
1607         /* mask all interrupts */
1608         dwc3_writel(dwc->regs, DWC3_DEVTEN, 0x00);
1609 }
1610
1611 static irqreturn_t dwc3_interrupt(int irq, void *_dwc);
1612 static irqreturn_t dwc3_thread_interrupt(int irq, void *_dwc);
1613
1614 /**
1615  * dwc3_gadget_setup_nump - Calculate and initialize NUMP field of DCFG
1616  * dwc: pointer to our context structure
1617  *
1618  * The following looks like complex but it's actually very simple. In order to
1619  * calculate the number of packets we can burst at once on OUT transfers, we're
1620  * gonna use RxFIFO size.
1621  *
1622  * To calculate RxFIFO size we need two numbers:
1623  * MDWIDTH = size, in bits, of the internal memory bus
1624  * RAM2_DEPTH = depth, in MDWIDTH, of internal RAM2 (where RxFIFO sits)
1625  *
1626  * Given these two numbers, the formula is simple:
1627  *
1628  * RxFIFO Size = (RAM2_DEPTH * MDWIDTH / 8) - 24 - 16;
1629  *
1630  * 24 bytes is for 3x SETUP packets
1631  * 16 bytes is a clock domain crossing tolerance
1632  *
1633  * Given RxFIFO Size, NUMP = RxFIFOSize / 1024;
1634  */
1635 static void dwc3_gadget_setup_nump(struct dwc3 *dwc)
1636 {
1637         u32 ram2_depth;
1638         u32 mdwidth;
1639         u32 nump;
1640         u32 reg;
1641
1642         ram2_depth = DWC3_GHWPARAMS7_RAM2_DEPTH(dwc->hwparams.hwparams7);
1643         mdwidth = DWC3_GHWPARAMS0_MDWIDTH(dwc->hwparams.hwparams0);
1644
1645         nump = ((ram2_depth * mdwidth / 8) - 24 - 16) / 1024;
1646         nump = min_t(u32, nump, 16);
1647
1648         /* update NumP */
1649         reg = dwc3_readl(dwc->regs, DWC3_DCFG);
1650         reg &= ~DWC3_DCFG_NUMP_MASK;
1651         reg |= nump << DWC3_DCFG_NUMP_SHIFT;
1652         dwc3_writel(dwc->regs, DWC3_DCFG, reg);
1653 }
1654
1655 static int __dwc3_gadget_start(struct dwc3 *dwc)
1656 {
1657         struct dwc3_ep          *dep;
1658         int                     ret = 0;
1659         u32                     reg;
1660
1661         reg = dwc3_readl(dwc->regs, DWC3_DCFG);
1662         reg &= ~(DWC3_DCFG_SPEED_MASK);
1663
1664         /**
1665          * WORKAROUND: DWC3 revision < 2.20a have an issue
1666          * which would cause metastability state on Run/Stop
1667          * bit if we try to force the IP to USB2-only mode.
1668          *
1669          * Because of that, we cannot configure the IP to any
1670          * speed other than the SuperSpeed
1671          *
1672          * Refers to:
1673          *
1674          * STAR#9000525659: Clock Domain Crossing on DCTL in
1675          * USB 2.0 Mode
1676          */
1677         if (dwc->revision < DWC3_REVISION_220A) {
1678                 reg |= DWC3_DCFG_SUPERSPEED;
1679         } else {
1680                 switch (dwc->maximum_speed) {
1681                 case USB_SPEED_LOW:
1682                         reg |= DWC3_DSTS_LOWSPEED;
1683                         break;
1684                 case USB_SPEED_FULL:
1685                         reg |= DWC3_DSTS_FULLSPEED1;
1686                         break;
1687                 case USB_SPEED_HIGH:
1688                         reg |= DWC3_DSTS_HIGHSPEED;
1689                         break;
1690                 case USB_SPEED_SUPER:   /* FALLTHROUGH */
1691                 case USB_SPEED_UNKNOWN: /* FALTHROUGH */
1692                 default:
1693                         reg |= DWC3_DSTS_SUPERSPEED;
1694                 }
1695         }
1696         dwc3_writel(dwc->regs, DWC3_DCFG, reg);
1697
1698         /*
1699          * We are telling dwc3 that we want to use DCFG.NUMP as ACK TP's NUMP
1700          * field instead of letting dwc3 itself calculate that automatically.
1701          *
1702          * This way, we maximize the chances that we'll be able to get several
1703          * bursts of data without going through any sort of endpoint throttling.
1704          */
1705         reg = dwc3_readl(dwc->regs, DWC3_GRXTHRCFG);
1706         reg &= ~DWC3_GRXTHRCFG_PKTCNTSEL;
1707         dwc3_writel(dwc->regs, DWC3_GRXTHRCFG, reg);
1708
1709         dwc3_gadget_setup_nump(dwc);
1710
1711         /* Start with SuperSpeed Default */
1712         dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
1713
1714         dep = dwc->eps[0];
1715         ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL, false,
1716                         false);
1717         if (ret) {
1718                 dev_err(dwc->dev, "failed to enable %s\n", dep->name);
1719                 goto err0;
1720         }
1721
1722         dep = dwc->eps[1];
1723         ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL, false,
1724                         false);
1725         if (ret) {
1726                 dev_err(dwc->dev, "failed to enable %s\n", dep->name);
1727                 goto err1;
1728         }
1729
1730         /* begin to receive SETUP packets */
1731         dwc->ep0state = EP0_SETUP_PHASE;
1732         dwc3_ep0_out_start(dwc);
1733
1734         dwc3_gadget_enable_irq(dwc);
1735
1736         return 0;
1737
1738 err1:
1739         __dwc3_gadget_ep_disable(dwc->eps[0]);
1740
1741 err0:
1742         return ret;
1743 }
1744
1745 static int dwc3_gadget_start(struct usb_gadget *g,
1746                 struct usb_gadget_driver *driver)
1747 {
1748         struct dwc3             *dwc = gadget_to_dwc(g);
1749         unsigned long           flags;
1750         int                     ret = 0;
1751         int                     irq;
1752
1753         irq = platform_get_irq(to_platform_device(dwc->dev), 0);
1754         ret = request_threaded_irq(irq, dwc3_interrupt, dwc3_thread_interrupt,
1755                         IRQF_SHARED, "dwc3", dwc->ev_buf);
1756         if (ret) {
1757                 dev_err(dwc->dev, "failed to request irq #%d --> %d\n",
1758                                 irq, ret);
1759                 goto err0;
1760         }
1761
1762         spin_lock_irqsave(&dwc->lock, flags);
1763         if (dwc->gadget_driver) {
1764                 dev_err(dwc->dev, "%s is already bound to %s\n",
1765                                 dwc->gadget.name,
1766                                 dwc->gadget_driver->driver.name);
1767                 ret = -EBUSY;
1768                 goto err1;
1769         }
1770
1771         dwc->gadget_driver      = driver;
1772
1773         __dwc3_gadget_start(dwc);
1774         spin_unlock_irqrestore(&dwc->lock, flags);
1775
1776         return 0;
1777
1778 err1:
1779         spin_unlock_irqrestore(&dwc->lock, flags);
1780         free_irq(irq, dwc);
1781
1782 err0:
1783         return ret;
1784 }
1785
1786 static void __dwc3_gadget_stop(struct dwc3 *dwc)
1787 {
1788         dwc3_gadget_disable_irq(dwc);
1789         __dwc3_gadget_ep_disable(dwc->eps[0]);
1790         __dwc3_gadget_ep_disable(dwc->eps[1]);
1791 }
1792
1793 static int dwc3_gadget_stop(struct usb_gadget *g)
1794 {
1795         struct dwc3             *dwc = gadget_to_dwc(g);
1796         unsigned long           flags;
1797         int                     irq;
1798
1799         spin_lock_irqsave(&dwc->lock, flags);
1800         __dwc3_gadget_stop(dwc);
1801         dwc->gadget_driver      = NULL;
1802         spin_unlock_irqrestore(&dwc->lock, flags);
1803
1804         irq = platform_get_irq(to_platform_device(dwc->dev), 0);
1805         free_irq(irq, dwc->ev_buf);
1806
1807         return 0;
1808 }
1809
1810 static const struct usb_gadget_ops dwc3_gadget_ops = {
1811         .get_frame              = dwc3_gadget_get_frame,
1812         .wakeup                 = dwc3_gadget_wakeup,
1813         .set_selfpowered        = dwc3_gadget_set_selfpowered,
1814         .pullup                 = dwc3_gadget_pullup,
1815         .udc_start              = dwc3_gadget_start,
1816         .udc_stop               = dwc3_gadget_stop,
1817 };
1818
1819 /* -------------------------------------------------------------------------- */
1820
1821 static int dwc3_gadget_init_hw_endpoints(struct dwc3 *dwc,
1822                 u8 num, u32 direction)
1823 {
1824         struct dwc3_ep                  *dep;
1825         u8                              i;
1826
1827         for (i = 0; i < num; i++) {
1828                 u8 epnum = (i << 1) | (!!direction);
1829
1830                 dep = kzalloc(sizeof(*dep), GFP_KERNEL);
1831                 if (!dep)
1832                         return -ENOMEM;
1833
1834                 dep->dwc = dwc;
1835                 dep->number = epnum;
1836                 dep->direction = !!direction;
1837                 dwc->eps[epnum] = dep;
1838
1839                 snprintf(dep->name, sizeof(dep->name), "ep%d%s", epnum >> 1,
1840                                 (epnum & 1) ? "in" : "out");
1841
1842                 dep->endpoint.name = dep->name;
1843
1844                 dwc3_trace(trace_dwc3_gadget, "initializing %s", dep->name);
1845
1846                 if (epnum == 0 || epnum == 1) {
1847                         usb_ep_set_maxpacket_limit(&dep->endpoint, 512);
1848                         dep->endpoint.maxburst = 1;
1849                         dep->endpoint.ops = &dwc3_gadget_ep0_ops;
1850                         if (!epnum)
1851                                 dwc->gadget.ep0 = &dep->endpoint;
1852                 } else {
1853                         int             ret;
1854
1855                         usb_ep_set_maxpacket_limit(&dep->endpoint, 1024);
1856                         dep->endpoint.max_streams = 15;
1857                         dep->endpoint.ops = &dwc3_gadget_ep_ops;
1858                         list_add_tail(&dep->endpoint.ep_list,
1859                                         &dwc->gadget.ep_list);
1860
1861                         ret = dwc3_alloc_trb_pool(dep);
1862                         if (ret)
1863                                 return ret;
1864                 }
1865
1866                 if (epnum == 0 || epnum == 1) {
1867                         dep->endpoint.caps.type_control = true;
1868                 } else {
1869                         dep->endpoint.caps.type_iso = true;
1870                         dep->endpoint.caps.type_bulk = true;
1871                         dep->endpoint.caps.type_int = true;
1872                 }
1873
1874                 dep->endpoint.caps.dir_in = !!direction;
1875                 dep->endpoint.caps.dir_out = !direction;
1876
1877                 INIT_LIST_HEAD(&dep->pending_list);
1878                 INIT_LIST_HEAD(&dep->started_list);
1879         }
1880
1881         return 0;
1882 }
1883
1884 static int dwc3_gadget_init_endpoints(struct dwc3 *dwc)
1885 {
1886         int                             ret;
1887
1888         INIT_LIST_HEAD(&dwc->gadget.ep_list);
1889
1890         ret = dwc3_gadget_init_hw_endpoints(dwc, dwc->num_out_eps, 0);
1891         if (ret < 0) {
1892                 dwc3_trace(trace_dwc3_gadget,
1893                                 "failed to allocate OUT endpoints");
1894                 return ret;
1895         }
1896
1897         ret = dwc3_gadget_init_hw_endpoints(dwc, dwc->num_in_eps, 1);
1898         if (ret < 0) {
1899                 dwc3_trace(trace_dwc3_gadget,
1900                                 "failed to allocate IN endpoints");
1901                 return ret;
1902         }
1903
1904         return 0;
1905 }
1906
1907 static void dwc3_gadget_free_endpoints(struct dwc3 *dwc)
1908 {
1909         struct dwc3_ep                  *dep;
1910         u8                              epnum;
1911
1912         for (epnum = 0; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
1913                 dep = dwc->eps[epnum];
1914                 if (!dep)
1915                         continue;
1916                 /*
1917                  * Physical endpoints 0 and 1 are special; they form the
1918                  * bi-directional USB endpoint 0.
1919                  *
1920                  * For those two physical endpoints, we don't allocate a TRB
1921                  * pool nor do we add them the endpoints list. Due to that, we
1922                  * shouldn't do these two operations otherwise we would end up
1923                  * with all sorts of bugs when removing dwc3.ko.
1924                  */
1925                 if (epnum != 0 && epnum != 1) {
1926                         dwc3_free_trb_pool(dep);
1927                         list_del(&dep->endpoint.ep_list);
1928                 }
1929
1930                 kfree(dep);
1931         }
1932 }
1933
1934 /* -------------------------------------------------------------------------- */
1935
1936 static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
1937                 struct dwc3_request *req, struct dwc3_trb *trb,
1938                 const struct dwc3_event_depevt *event, int status)
1939 {
1940         unsigned int            count;
1941         unsigned int            s_pkt = 0;
1942         unsigned int            trb_status;
1943
1944         trace_dwc3_complete_trb(dep, trb);
1945
1946         if ((trb->ctrl & DWC3_TRB_CTRL_HWO) && status != -ESHUTDOWN)
1947                 /*
1948                  * We continue despite the error. There is not much we
1949                  * can do. If we don't clean it up we loop forever. If
1950                  * we skip the TRB then it gets overwritten after a
1951                  * while since we use them in a ring buffer. A BUG()
1952                  * would help. Lets hope that if this occurs, someone
1953                  * fixes the root cause instead of looking away :)
1954                  */
1955                 dev_err(dwc->dev, "%s's TRB (%p) still owned by HW\n",
1956                                 dep->name, trb);
1957         count = trb->size & DWC3_TRB_SIZE_MASK;
1958
1959         if (dep->direction) {
1960                 if (count) {
1961                         trb_status = DWC3_TRB_SIZE_TRBSTS(trb->size);
1962                         if (trb_status == DWC3_TRBSTS_MISSED_ISOC) {
1963                                 dwc3_trace(trace_dwc3_gadget,
1964                                                 "%s: incomplete IN transfer\n",
1965                                                 dep->name);
1966                                 /*
1967                                  * If missed isoc occurred and there is
1968                                  * no request queued then issue END
1969                                  * TRANSFER, so that core generates
1970                                  * next xfernotready and we will issue
1971                                  * a fresh START TRANSFER.
1972                                  * If there are still queued request
1973                                  * then wait, do not issue either END
1974                                  * or UPDATE TRANSFER, just attach next
1975                                  * request in pending_list during
1976                                  * giveback.If any future queued request
1977                                  * is successfully transferred then we
1978                                  * will issue UPDATE TRANSFER for all
1979                                  * request in the pending_list.
1980                                  */
1981                                 dep->flags |= DWC3_EP_MISSED_ISOC;
1982                         } else {
1983                                 dev_err(dwc->dev, "incomplete IN transfer %s\n",
1984                                                 dep->name);
1985                                 status = -ECONNRESET;
1986                         }
1987                 } else {
1988                         dep->flags &= ~DWC3_EP_MISSED_ISOC;
1989                 }
1990         } else {
1991                 if (count && (event->status & DEPEVT_STATUS_SHORT))
1992                         s_pkt = 1;
1993         }
1994
1995         /*
1996          * We assume here we will always receive the entire data block
1997          * which we should receive. Meaning, if we program RX to
1998          * receive 4K but we receive only 2K, we assume that's all we
1999          * should receive and we simply bounce the request back to the
2000          * gadget driver for further processing.
2001          */
2002         req->request.actual += req->request.length - count;
2003         if (s_pkt)
2004                 return 1;
2005         if ((event->status & DEPEVT_STATUS_LST) &&
2006                         (trb->ctrl & (DWC3_TRB_CTRL_LST |
2007                                 DWC3_TRB_CTRL_HWO)))
2008                 return 1;
2009         if ((event->status & DEPEVT_STATUS_IOC) &&
2010                         (trb->ctrl & DWC3_TRB_CTRL_IOC))
2011                 return 1;
2012         return 0;
2013 }
2014
2015 static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
2016                 const struct dwc3_event_depevt *event, int status)
2017 {
2018         struct dwc3_request     *req;
2019         struct dwc3_trb         *trb;
2020         unsigned int            slot;
2021         unsigned int            i;
2022         int                     ret;
2023
2024         do {
2025                 req = next_request(&dep->started_list);
2026                 if (WARN_ON_ONCE(!req))
2027                         return 1;
2028
2029                 i = 0;
2030                 do {
2031                         slot = req->first_trb_index + i;
2032                         if (slot == DWC3_TRB_NUM - 1)
2033                                 slot++;
2034                         slot %= DWC3_TRB_NUM;
2035                         trb = &dep->trb_pool[slot];
2036
2037                         ret = __dwc3_cleanup_done_trbs(dwc, dep, req, trb,
2038                                         event, status);
2039                         if (ret)
2040                                 break;
2041                 } while (++i < req->request.num_mapped_sgs);
2042
2043                 dwc3_gadget_giveback(dep, req, status);
2044
2045                 if (ret)
2046                         break;
2047         } while (1);
2048
2049         if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
2050                         list_empty(&dep->started_list)) {
2051                 if (list_empty(&dep->pending_list)) {
2052                         /*
2053                          * If there is no entry in request list then do
2054                          * not issue END TRANSFER now. Just set PENDING
2055                          * flag, so that END TRANSFER is issued when an
2056                          * entry is added into request list.
2057                          */
2058                         dep->flags = DWC3_EP_PENDING_REQUEST;
2059                 } else {
2060                         dwc3_stop_active_transfer(dwc, dep->number, true);
2061                         dep->flags = DWC3_EP_ENABLED;
2062                 }
2063                 return 1;
2064         }
2065
2066         return 1;
2067 }
2068
2069 static void dwc3_endpoint_transfer_complete(struct dwc3 *dwc,
2070                 struct dwc3_ep *dep, const struct dwc3_event_depevt *event)
2071 {
2072         unsigned                status = 0;
2073         int                     clean_busy;
2074         u32                     is_xfer_complete;
2075
2076         is_xfer_complete = (event->endpoint_event == DWC3_DEPEVT_XFERCOMPLETE);
2077
2078         if (event->status & DEPEVT_STATUS_BUSERR)
2079                 status = -ECONNRESET;
2080
2081         clean_busy = dwc3_cleanup_done_reqs(dwc, dep, event, status);
2082         if (clean_busy && (is_xfer_complete ||
2083                                 usb_endpoint_xfer_isoc(dep->endpoint.desc)))
2084                 dep->flags &= ~DWC3_EP_BUSY;
2085
2086         /*
2087          * WORKAROUND: This is the 2nd half of U1/U2 -> U0 workaround.
2088          * See dwc3_gadget_linksts_change_interrupt() for 1st half.
2089          */
2090         if (dwc->revision < DWC3_REVISION_183A) {
2091                 u32             reg;
2092                 int             i;
2093
2094                 for (i = 0; i < DWC3_ENDPOINTS_NUM; i++) {
2095                         dep = dwc->eps[i];
2096
2097                         if (!(dep->flags & DWC3_EP_ENABLED))
2098                                 continue;
2099
2100                         if (!list_empty(&dep->started_list))
2101                                 return;
2102                 }
2103
2104                 reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2105                 reg |= dwc->u1u2;
2106                 dwc3_writel(dwc->regs, DWC3_DCTL, reg);
2107
2108                 dwc->u1u2 = 0;
2109         }
2110
2111         if (!usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
2112                 int ret;
2113
2114                 ret = __dwc3_gadget_kick_transfer(dep, 0);
2115                 if (!ret || ret == -EBUSY)
2116                         return;
2117         }
2118 }
2119
2120 static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
2121                 const struct dwc3_event_depevt *event)
2122 {
2123         struct dwc3_ep          *dep;
2124         u8                      epnum = event->endpoint_number;
2125
2126         dep = dwc->eps[epnum];
2127
2128         if (!(dep->flags & DWC3_EP_ENABLED))
2129                 return;
2130
2131         if (epnum == 0 || epnum == 1) {
2132                 dwc3_ep0_interrupt(dwc, event);
2133                 return;
2134         }
2135
2136         switch (event->endpoint_event) {
2137         case DWC3_DEPEVT_XFERCOMPLETE:
2138                 dep->resource_index = 0;
2139
2140                 if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
2141                         dwc3_trace(trace_dwc3_gadget,
2142                                         "%s is an Isochronous endpoint\n",
2143                                         dep->name);
2144                         return;
2145                 }
2146
2147                 dwc3_endpoint_transfer_complete(dwc, dep, event);
2148                 break;
2149         case DWC3_DEPEVT_XFERINPROGRESS:
2150                 dwc3_endpoint_transfer_complete(dwc, dep, event);
2151                 break;
2152         case DWC3_DEPEVT_XFERNOTREADY:
2153                 if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
2154                         dwc3_gadget_start_isoc(dwc, dep, event);
2155                 } else {
2156                         int active;
2157                         int ret;
2158
2159                         active = event->status & DEPEVT_STATUS_TRANSFER_ACTIVE;
2160
2161                         dwc3_trace(trace_dwc3_gadget, "%s: reason %s",
2162                                         dep->name, active ? "Transfer Active"
2163                                         : "Transfer Not Active");
2164
2165                         ret = __dwc3_gadget_kick_transfer(dep, 0);
2166                         if (!ret || ret == -EBUSY)
2167                                 return;
2168
2169                         dwc3_trace(trace_dwc3_gadget,
2170                                         "%s: failed to kick transfers\n",
2171                                         dep->name);
2172                 }
2173
2174                 break;
2175         case DWC3_DEPEVT_STREAMEVT:
2176                 if (!usb_endpoint_xfer_bulk(dep->endpoint.desc)) {
2177                         dev_err(dwc->dev, "Stream event for non-Bulk %s\n",
2178                                         dep->name);
2179                         return;
2180                 }
2181
2182                 switch (event->status) {
2183                 case DEPEVT_STREAMEVT_FOUND:
2184                         dwc3_trace(trace_dwc3_gadget,
2185                                         "Stream %d found and started",
2186                                         event->parameters);
2187
2188                         break;
2189                 case DEPEVT_STREAMEVT_NOTFOUND:
2190                         /* FALLTHROUGH */
2191                 default:
2192                         dwc3_trace(trace_dwc3_gadget,
2193                                         "unable to find suitable stream\n");
2194                 }
2195                 break;
2196         case DWC3_DEPEVT_RXTXFIFOEVT:
2197                 dwc3_trace(trace_dwc3_gadget, "%s FIFO Overrun\n", dep->name);
2198                 break;
2199         case DWC3_DEPEVT_EPCMDCMPLT:
2200                 dwc3_trace(trace_dwc3_gadget, "Endpoint Command Complete");
2201                 break;
2202         }
2203 }
2204
2205 static void dwc3_disconnect_gadget(struct dwc3 *dwc)
2206 {
2207         if (dwc->gadget_driver && dwc->gadget_driver->disconnect) {
2208                 spin_unlock(&dwc->lock);
2209                 dwc->gadget_driver->disconnect(&dwc->gadget);
2210                 spin_lock(&dwc->lock);
2211         }
2212 }
2213
2214 static void dwc3_suspend_gadget(struct dwc3 *dwc)
2215 {
2216         if (dwc->gadget_driver && dwc->gadget_driver->suspend) {
2217                 spin_unlock(&dwc->lock);
2218                 dwc->gadget_driver->suspend(&dwc->gadget);
2219                 spin_lock(&dwc->lock);
2220         }
2221 }
2222
2223 static void dwc3_resume_gadget(struct dwc3 *dwc)
2224 {
2225         if (dwc->gadget_driver && dwc->gadget_driver->resume) {
2226                 spin_unlock(&dwc->lock);
2227                 dwc->gadget_driver->resume(&dwc->gadget);
2228                 spin_lock(&dwc->lock);
2229         }
2230 }
2231
2232 static void dwc3_reset_gadget(struct dwc3 *dwc)
2233 {
2234         if (!dwc->gadget_driver)
2235                 return;
2236
2237         if (dwc->gadget.speed != USB_SPEED_UNKNOWN) {
2238                 spin_unlock(&dwc->lock);
2239                 usb_gadget_udc_reset(&dwc->gadget, dwc->gadget_driver);
2240                 spin_lock(&dwc->lock);
2241         }
2242 }
2243
2244 static void dwc3_stop_active_transfer(struct dwc3 *dwc, u32 epnum, bool force)
2245 {
2246         struct dwc3_ep *dep;
2247         struct dwc3_gadget_ep_cmd_params params;
2248         u32 cmd;
2249         int ret;
2250
2251         dep = dwc->eps[epnum];
2252
2253         if (!dep->resource_index)
2254                 return;
2255
2256         /*
2257          * NOTICE: We are violating what the Databook says about the
2258          * EndTransfer command. Ideally we would _always_ wait for the
2259          * EndTransfer Command Completion IRQ, but that's causing too
2260          * much trouble synchronizing between us and gadget driver.
2261          *
2262          * We have discussed this with the IP Provider and it was
2263          * suggested to giveback all requests here, but give HW some
2264          * extra time to synchronize with the interconnect. We're using
2265          * an arbitrary 100us delay for that.
2266          *
2267          * Note also that a similar handling was tested by Synopsys
2268          * (thanks a lot Paul) and nothing bad has come out of it.
2269          * In short, what we're doing is:
2270          *
2271          * - Issue EndTransfer WITH CMDIOC bit set
2272          * - Wait 100us
2273          */
2274
2275         cmd = DWC3_DEPCMD_ENDTRANSFER;
2276         cmd |= force ? DWC3_DEPCMD_HIPRI_FORCERM : 0;
2277         cmd |= DWC3_DEPCMD_CMDIOC;
2278         cmd |= DWC3_DEPCMD_PARAM(dep->resource_index);
2279         memset(&params, 0, sizeof(params));
2280         ret = dwc3_send_gadget_ep_cmd(dep, cmd, &params);
2281         WARN_ON_ONCE(ret);
2282         dep->resource_index = 0;
2283         dep->flags &= ~DWC3_EP_BUSY;
2284         udelay(100);
2285 }
2286
2287 static void dwc3_stop_active_transfers(struct dwc3 *dwc)
2288 {
2289         u32 epnum;
2290
2291         for (epnum = 2; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
2292                 struct dwc3_ep *dep;
2293
2294                 dep = dwc->eps[epnum];
2295                 if (!dep)
2296                         continue;
2297
2298                 if (!(dep->flags & DWC3_EP_ENABLED))
2299                         continue;
2300
2301                 dwc3_remove_requests(dwc, dep);
2302         }
2303 }
2304
2305 static void dwc3_clear_stall_all_ep(struct dwc3 *dwc)
2306 {
2307         u32 epnum;
2308
2309         for (epnum = 1; epnum < DWC3_ENDPOINTS_NUM; epnum++) {
2310                 struct dwc3_ep *dep;
2311                 int ret;
2312
2313                 dep = dwc->eps[epnum];
2314                 if (!dep)
2315                         continue;
2316
2317                 if (!(dep->flags & DWC3_EP_STALL))
2318                         continue;
2319
2320                 dep->flags &= ~DWC3_EP_STALL;
2321
2322                 ret = dwc3_send_clear_stall_ep_cmd(dep);
2323                 WARN_ON_ONCE(ret);
2324         }
2325 }
2326
2327 static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
2328 {
2329         int                     reg;
2330
2331         reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2332         reg &= ~DWC3_DCTL_INITU1ENA;
2333         dwc3_writel(dwc->regs, DWC3_DCTL, reg);
2334
2335         reg &= ~DWC3_DCTL_INITU2ENA;
2336         dwc3_writel(dwc->regs, DWC3_DCTL, reg);
2337
2338         dwc3_disconnect_gadget(dwc);
2339
2340         dwc->gadget.speed = USB_SPEED_UNKNOWN;
2341         dwc->setup_packet_pending = false;
2342         usb_gadget_set_state(&dwc->gadget, USB_STATE_NOTATTACHED);
2343 }
2344
2345 static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
2346 {
2347         u32                     reg;
2348
2349         /*
2350          * WORKAROUND: DWC3 revisions <1.88a have an issue which
2351          * would cause a missing Disconnect Event if there's a
2352          * pending Setup Packet in the FIFO.
2353          *
2354          * There's no suggested workaround on the official Bug
2355          * report, which states that "unless the driver/application
2356          * is doing any special handling of a disconnect event,
2357          * there is no functional issue".
2358          *
2359          * Unfortunately, it turns out that we _do_ some special
2360          * handling of a disconnect event, namely complete all
2361          * pending transfers, notify gadget driver of the
2362          * disconnection, and so on.
2363          *
2364          * Our suggested workaround is to follow the Disconnect
2365          * Event steps here, instead, based on a setup_packet_pending
2366          * flag. Such flag gets set whenever we have a SETUP_PENDING
2367          * status for EP0 TRBs and gets cleared on XferComplete for the
2368          * same endpoint.
2369          *
2370          * Refers to:
2371          *
2372          * STAR#9000466709: RTL: Device : Disconnect event not
2373          * generated if setup packet pending in FIFO
2374          */
2375         if (dwc->revision < DWC3_REVISION_188A) {
2376                 if (dwc->setup_packet_pending)
2377                         dwc3_gadget_disconnect_interrupt(dwc);
2378         }
2379
2380         dwc3_reset_gadget(dwc);
2381
2382         reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2383         reg &= ~DWC3_DCTL_TSTCTRL_MASK;
2384         dwc3_writel(dwc->regs, DWC3_DCTL, reg);
2385         dwc->test_mode = false;
2386
2387         dwc3_stop_active_transfers(dwc);
2388         dwc3_clear_stall_all_ep(dwc);
2389
2390         /* Reset device address to zero */
2391         reg = dwc3_readl(dwc->regs, DWC3_DCFG);
2392         reg &= ~(DWC3_DCFG_DEVADDR_MASK);
2393         dwc3_writel(dwc->regs, DWC3_DCFG, reg);
2394 }
2395
2396 static void dwc3_update_ram_clk_sel(struct dwc3 *dwc, u32 speed)
2397 {
2398         u32 reg;
2399         u32 usb30_clock = DWC3_GCTL_CLK_BUS;
2400
2401         /*
2402          * We change the clock only at SS but I dunno why I would want to do
2403          * this. Maybe it becomes part of the power saving plan.
2404          */
2405
2406         if (speed != DWC3_DSTS_SUPERSPEED)
2407                 return;
2408
2409         /*
2410          * RAMClkSel is reset to 0 after USB reset, so it must be reprogrammed
2411          * each time on Connect Done.
2412          */
2413         if (!usb30_clock)
2414                 return;
2415
2416         reg = dwc3_readl(dwc->regs, DWC3_GCTL);
2417         reg |= DWC3_GCTL_RAMCLKSEL(usb30_clock);
2418         dwc3_writel(dwc->regs, DWC3_GCTL, reg);
2419 }
2420
2421 static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
2422 {
2423         struct dwc3_ep          *dep;
2424         int                     ret;
2425         u32                     reg;
2426         u8                      speed;
2427
2428         reg = dwc3_readl(dwc->regs, DWC3_DSTS);
2429         speed = reg & DWC3_DSTS_CONNECTSPD;
2430         dwc->speed = speed;
2431
2432         dwc3_update_ram_clk_sel(dwc, speed);
2433
2434         switch (speed) {
2435         case DWC3_DCFG_SUPERSPEED:
2436                 /*
2437                  * WORKAROUND: DWC3 revisions <1.90a have an issue which
2438                  * would cause a missing USB3 Reset event.
2439                  *
2440                  * In such situations, we should force a USB3 Reset
2441                  * event by calling our dwc3_gadget_reset_interrupt()
2442                  * routine.
2443                  *
2444                  * Refers to:
2445                  *
2446                  * STAR#9000483510: RTL: SS : USB3 reset event may
2447                  * not be generated always when the link enters poll
2448                  */
2449                 if (dwc->revision < DWC3_REVISION_190A)
2450                         dwc3_gadget_reset_interrupt(dwc);
2451
2452                 dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(512);
2453                 dwc->gadget.ep0->maxpacket = 512;
2454                 dwc->gadget.speed = USB_SPEED_SUPER;
2455                 break;
2456         case DWC3_DCFG_HIGHSPEED:
2457                 dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(64);
2458                 dwc->gadget.ep0->maxpacket = 64;
2459                 dwc->gadget.speed = USB_SPEED_HIGH;
2460                 break;
2461         case DWC3_DCFG_FULLSPEED2:
2462         case DWC3_DCFG_FULLSPEED1:
2463                 dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(64);
2464                 dwc->gadget.ep0->maxpacket = 64;
2465                 dwc->gadget.speed = USB_SPEED_FULL;
2466                 break;
2467         case DWC3_DCFG_LOWSPEED:
2468                 dwc3_gadget_ep0_desc.wMaxPacketSize = cpu_to_le16(8);
2469                 dwc->gadget.ep0->maxpacket = 8;
2470                 dwc->gadget.speed = USB_SPEED_LOW;
2471                 break;
2472         }
2473
2474         /* Enable USB2 LPM Capability */
2475
2476         if ((dwc->revision > DWC3_REVISION_194A)
2477                         && (speed != DWC3_DCFG_SUPERSPEED)) {
2478                 reg = dwc3_readl(dwc->regs, DWC3_DCFG);
2479                 reg |= DWC3_DCFG_LPM_CAP;
2480                 dwc3_writel(dwc->regs, DWC3_DCFG, reg);
2481
2482                 reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2483                 reg &= ~(DWC3_DCTL_HIRD_THRES_MASK | DWC3_DCTL_L1_HIBER_EN);
2484
2485                 reg |= DWC3_DCTL_HIRD_THRES(dwc->hird_threshold);
2486
2487                 /*
2488                  * When dwc3 revisions >= 2.40a, LPM Erratum is enabled and
2489                  * DCFG.LPMCap is set, core responses with an ACK and the
2490                  * BESL value in the LPM token is less than or equal to LPM
2491                  * NYET threshold.
2492                  */
2493                 WARN_ONCE(dwc->revision < DWC3_REVISION_240A
2494                                 && dwc->has_lpm_erratum,
2495                                 "LPM Erratum not available on dwc3 revisisions < 2.40a\n");
2496
2497                 if (dwc->has_lpm_erratum && dwc->revision >= DWC3_REVISION_240A)
2498                         reg |= DWC3_DCTL_LPM_ERRATA(dwc->lpm_nyet_threshold);
2499
2500                 dwc3_writel(dwc->regs, DWC3_DCTL, reg);
2501         } else {
2502                 reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2503                 reg &= ~DWC3_DCTL_HIRD_THRES_MASK;
2504                 dwc3_writel(dwc->regs, DWC3_DCTL, reg);
2505         }
2506
2507         dep = dwc->eps[0];
2508         ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL, true,
2509                         false);
2510         if (ret) {
2511                 dev_err(dwc->dev, "failed to enable %s\n", dep->name);
2512                 return;
2513         }
2514
2515         dep = dwc->eps[1];
2516         ret = __dwc3_gadget_ep_enable(dep, &dwc3_gadget_ep0_desc, NULL, true,
2517                         false);
2518         if (ret) {
2519                 dev_err(dwc->dev, "failed to enable %s\n", dep->name);
2520                 return;
2521         }
2522
2523         /*
2524          * Configure PHY via GUSB3PIPECTLn if required.
2525          *
2526          * Update GTXFIFOSIZn
2527          *
2528          * In both cases reset values should be sufficient.
2529          */
2530 }
2531
2532 static void dwc3_gadget_wakeup_interrupt(struct dwc3 *dwc)
2533 {
2534         /*
2535          * TODO take core out of low power mode when that's
2536          * implemented.
2537          */
2538
2539         if (dwc->gadget_driver && dwc->gadget_driver->resume) {
2540                 spin_unlock(&dwc->lock);
2541                 dwc->gadget_driver->resume(&dwc->gadget);
2542                 spin_lock(&dwc->lock);
2543         }
2544 }
2545
2546 static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
2547                 unsigned int evtinfo)
2548 {
2549         enum dwc3_link_state    next = evtinfo & DWC3_LINK_STATE_MASK;
2550         unsigned int            pwropt;
2551
2552         /*
2553          * WORKAROUND: DWC3 < 2.50a have an issue when configured without
2554          * Hibernation mode enabled which would show up when device detects
2555          * host-initiated U3 exit.
2556          *
2557          * In that case, device will generate a Link State Change Interrupt
2558          * from U3 to RESUME which is only necessary if Hibernation is
2559          * configured in.
2560          *
2561          * There are no functional changes due to such spurious event and we
2562          * just need to ignore it.
2563          *
2564          * Refers to:
2565          *
2566          * STAR#9000570034 RTL: SS Resume event generated in non-Hibernation
2567          * operational mode
2568          */
2569         pwropt = DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1);
2570         if ((dwc->revision < DWC3_REVISION_250A) &&
2571                         (pwropt != DWC3_GHWPARAMS1_EN_PWROPT_HIB)) {
2572                 if ((dwc->link_state == DWC3_LINK_STATE_U3) &&
2573                                 (next == DWC3_LINK_STATE_RESUME)) {
2574                         dwc3_trace(trace_dwc3_gadget,
2575                                         "ignoring transition U3 -> Resume");
2576                         return;
2577                 }
2578         }
2579
2580         /*
2581          * WORKAROUND: DWC3 Revisions <1.83a have an issue which, depending
2582          * on the link partner, the USB session might do multiple entry/exit
2583          * of low power states before a transfer takes place.
2584          *
2585          * Due to this problem, we might experience lower throughput. The
2586          * suggested workaround is to disable DCTL[12:9] bits if we're
2587          * transitioning from U1/U2 to U0 and enable those bits again
2588          * after a transfer completes and there are no pending transfers
2589          * on any of the enabled endpoints.
2590          *
2591          * This is the first half of that workaround.
2592          *
2593          * Refers to:
2594          *
2595          * STAR#9000446952: RTL: Device SS : if U1/U2 ->U0 takes >128us
2596          * core send LGO_Ux entering U0
2597          */
2598         if (dwc->revision < DWC3_REVISION_183A) {
2599                 if (next == DWC3_LINK_STATE_U0) {
2600                         u32     u1u2;
2601                         u32     reg;
2602
2603                         switch (dwc->link_state) {
2604                         case DWC3_LINK_STATE_U1:
2605                         case DWC3_LINK_STATE_U2:
2606                                 reg = dwc3_readl(dwc->regs, DWC3_DCTL);
2607                                 u1u2 = reg & (DWC3_DCTL_INITU2ENA
2608                                                 | DWC3_DCTL_ACCEPTU2ENA
2609                                                 | DWC3_DCTL_INITU1ENA
2610                                                 | DWC3_DCTL_ACCEPTU1ENA);
2611
2612                                 if (!dwc->u1u2)
2613                                         dwc->u1u2 = reg & u1u2;
2614
2615                                 reg &= ~u1u2;
2616
2617                                 dwc3_writel(dwc->regs, DWC3_DCTL, reg);
2618                                 break;
2619                         default:
2620                                 /* do nothing */
2621                                 break;
2622                         }
2623                 }
2624         }
2625
2626         switch (next) {
2627         case DWC3_LINK_STATE_U1:
2628                 if (dwc->speed == USB_SPEED_SUPER)
2629                         dwc3_suspend_gadget(dwc);
2630                 break;
2631         case DWC3_LINK_STATE_U2:
2632         case DWC3_LINK_STATE_U3:
2633                 dwc3_suspend_gadget(dwc);
2634                 break;
2635         case DWC3_LINK_STATE_RESUME:
2636                 dwc3_resume_gadget(dwc);
2637                 break;
2638         default:
2639                 /* do nothing */
2640                 break;
2641         }
2642
2643         dwc->link_state = next;
2644 }
2645
2646 static void dwc3_gadget_hibernation_interrupt(struct dwc3 *dwc,
2647                 unsigned int evtinfo)
2648 {
2649         unsigned int is_ss = evtinfo & BIT(4);
2650
2651         /**
2652          * WORKAROUND: DWC3 revison 2.20a with hibernation support
2653          * have a known issue which can cause USB CV TD.9.23 to fail
2654          * randomly.
2655          *
2656          * Because of this issue, core could generate bogus hibernation
2657          * events which SW needs to ignore.
2658          *
2659          * Refers to:
2660          *
2661          * STAR#9000546576: Device Mode Hibernation: Issue in USB 2.0
2662          * Device Fallback from SuperSpeed
2663          */
2664         if (is_ss ^ (dwc->speed == USB_SPEED_SUPER))
2665                 return;
2666
2667         /* enter hibernation here */
2668 }
2669
2670 static void dwc3_gadget_interrupt(struct dwc3 *dwc,
2671                 const struct dwc3_event_devt *event)
2672 {
2673         switch (event->type) {
2674         case DWC3_DEVICE_EVENT_DISCONNECT:
2675                 dwc3_gadget_disconnect_interrupt(dwc);
2676                 break;
2677         case DWC3_DEVICE_EVENT_RESET:
2678                 dwc3_gadget_reset_interrupt(dwc);
2679                 break;
2680         case DWC3_DEVICE_EVENT_CONNECT_DONE:
2681                 dwc3_gadget_conndone_interrupt(dwc);
2682                 break;
2683         case DWC3_DEVICE_EVENT_WAKEUP:
2684                 dwc3_gadget_wakeup_interrupt(dwc);
2685                 break;
2686         case DWC3_DEVICE_EVENT_HIBER_REQ:
2687                 if (dev_WARN_ONCE(dwc->dev, !dwc->has_hibernation,
2688                                         "unexpected hibernation event\n"))
2689                         break;
2690
2691                 dwc3_gadget_hibernation_interrupt(dwc, event->event_info);
2692                 break;
2693         case DWC3_DEVICE_EVENT_LINK_STATUS_CHANGE:
2694                 dwc3_gadget_linksts_change_interrupt(dwc, event->event_info);
2695                 break;
2696         case DWC3_DEVICE_EVENT_EOPF:
2697                 dwc3_trace(trace_dwc3_gadget, "End of Periodic Frame");
2698                 break;
2699         case DWC3_DEVICE_EVENT_SOF:
2700                 dwc3_trace(trace_dwc3_gadget, "Start of Periodic Frame");
2701                 break;
2702         case DWC3_DEVICE_EVENT_ERRATIC_ERROR:
2703                 dwc3_trace(trace_dwc3_gadget, "Erratic Error");
2704                 break;
2705         case DWC3_DEVICE_EVENT_CMD_CMPL:
2706                 dwc3_trace(trace_dwc3_gadget, "Command Complete");
2707                 break;
2708         case DWC3_DEVICE_EVENT_OVERFLOW:
2709                 dwc3_trace(trace_dwc3_gadget, "Overflow");
2710                 break;
2711         default:
2712                 dev_WARN(dwc->dev, "UNKNOWN IRQ %d\n", event->type);
2713         }
2714 }
2715
2716 static void dwc3_process_event_entry(struct dwc3 *dwc,
2717                 const union dwc3_event *event)
2718 {
2719         trace_dwc3_event(event->raw);
2720
2721         /* Endpoint IRQ, handle it and return early */
2722         if (event->type.is_devspec == 0) {
2723                 /* depevt */
2724                 return dwc3_endpoint_interrupt(dwc, &event->depevt);
2725         }
2726
2727         switch (event->type.type) {
2728         case DWC3_EVENT_TYPE_DEV:
2729                 dwc3_gadget_interrupt(dwc, &event->devt);
2730                 break;
2731         /* REVISIT what to do with Carkit and I2C events ? */
2732         default:
2733                 dev_err(dwc->dev, "UNKNOWN IRQ type %d\n", event->raw);
2734         }
2735 }
2736
2737 static irqreturn_t dwc3_process_event_buf(struct dwc3_event_buffer *evt)
2738 {
2739         struct dwc3 *dwc = evt->dwc;
2740         irqreturn_t ret = IRQ_NONE;
2741         int left;
2742         u32 reg;
2743
2744         left = evt->count;
2745
2746         if (!(evt->flags & DWC3_EVENT_PENDING))
2747                 return IRQ_NONE;
2748
2749         while (left > 0) {
2750                 union dwc3_event event;
2751
2752                 event.raw = *(u32 *) (evt->buf + evt->lpos);
2753
2754                 dwc3_process_event_entry(dwc, &event);
2755
2756                 /*
2757                  * FIXME we wrap around correctly to the next entry as
2758                  * almost all entries are 4 bytes in size. There is one
2759                  * entry which has 12 bytes which is a regular entry
2760                  * followed by 8 bytes data. ATM I don't know how
2761                  * things are organized if we get next to the a
2762                  * boundary so I worry about that once we try to handle
2763                  * that.
2764                  */
2765                 evt->lpos = (evt->lpos + 4) % DWC3_EVENT_BUFFERS_SIZE;
2766                 left -= 4;
2767
2768                 dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), 4);
2769         }
2770
2771         evt->count = 0;
2772         evt->flags &= ~DWC3_EVENT_PENDING;
2773         ret = IRQ_HANDLED;
2774
2775         /* Unmask interrupt */
2776         reg = dwc3_readl(dwc->regs, DWC3_GEVNTSIZ(0));
2777         reg &= ~DWC3_GEVNTSIZ_INTMASK;
2778         dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), reg);
2779
2780         return ret;
2781 }
2782
2783 static irqreturn_t dwc3_thread_interrupt(int irq, void *_evt)
2784 {
2785         struct dwc3_event_buffer *evt = _evt;
2786         struct dwc3 *dwc = evt->dwc;
2787         unsigned long flags;
2788         irqreturn_t ret = IRQ_NONE;
2789
2790         spin_lock_irqsave(&dwc->lock, flags);
2791         ret = dwc3_process_event_buf(evt);
2792         spin_unlock_irqrestore(&dwc->lock, flags);
2793
2794         return ret;
2795 }
2796
2797 static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt)
2798 {
2799         struct dwc3 *dwc = evt->dwc;
2800         u32 count;
2801         u32 reg;
2802
2803         count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0));
2804         count &= DWC3_GEVNTCOUNT_MASK;
2805         if (!count)
2806                 return IRQ_NONE;
2807
2808         evt->count = count;
2809         evt->flags |= DWC3_EVENT_PENDING;
2810
2811         /* Mask interrupt */
2812         reg = dwc3_readl(dwc->regs, DWC3_GEVNTSIZ(0));
2813         reg |= DWC3_GEVNTSIZ_INTMASK;
2814         dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0), reg);
2815
2816         return IRQ_WAKE_THREAD;
2817 }
2818
2819 static irqreturn_t dwc3_interrupt(int irq, void *_evt)
2820 {
2821         struct dwc3_event_buffer        *evt = _evt;
2822
2823         return dwc3_check_event_buf(evt);
2824 }
2825
2826 /**
2827  * dwc3_gadget_init - Initializes gadget related registers
2828  * @dwc: pointer to our controller context structure
2829  *
2830  * Returns 0 on success otherwise negative errno.
2831  */
2832 int dwc3_gadget_init(struct dwc3 *dwc)
2833 {
2834         int                                     ret;
2835
2836         dwc->ctrl_req = dma_alloc_coherent(dwc->dev, sizeof(*dwc->ctrl_req),
2837                         &dwc->ctrl_req_addr, GFP_KERNEL);
2838         if (!dwc->ctrl_req) {
2839                 dev_err(dwc->dev, "failed to allocate ctrl request\n");
2840                 ret = -ENOMEM;
2841                 goto err0;
2842         }
2843
2844         dwc->ep0_trb = dma_alloc_coherent(dwc->dev, sizeof(*dwc->ep0_trb) * 2,
2845                         &dwc->ep0_trb_addr, GFP_KERNEL);
2846         if (!dwc->ep0_trb) {
2847                 dev_err(dwc->dev, "failed to allocate ep0 trb\n");
2848                 ret = -ENOMEM;
2849                 goto err1;
2850         }
2851
2852         dwc->setup_buf = kzalloc(DWC3_EP0_BOUNCE_SIZE, GFP_KERNEL);
2853         if (!dwc->setup_buf) {
2854                 ret = -ENOMEM;
2855                 goto err2;
2856         }
2857
2858         dwc->ep0_bounce = dma_alloc_coherent(dwc->dev,
2859                         DWC3_EP0_BOUNCE_SIZE, &dwc->ep0_bounce_addr,
2860                         GFP_KERNEL);
2861         if (!dwc->ep0_bounce) {
2862                 dev_err(dwc->dev, "failed to allocate ep0 bounce buffer\n");
2863                 ret = -ENOMEM;
2864                 goto err3;
2865         }
2866
2867         dwc->zlp_buf = kzalloc(DWC3_ZLP_BUF_SIZE, GFP_KERNEL);
2868         if (!dwc->zlp_buf) {
2869                 ret = -ENOMEM;
2870                 goto err4;
2871         }
2872
2873         dwc->gadget.ops                 = &dwc3_gadget_ops;
2874         dwc->gadget.speed               = USB_SPEED_UNKNOWN;
2875         dwc->gadget.sg_supported        = true;
2876         dwc->gadget.name                = "dwc3-gadget";
2877         dwc->gadget.is_otg              = dwc->dr_mode == USB_DR_MODE_OTG;
2878
2879         /*
2880          * FIXME We might be setting max_speed to <SUPER, however versions
2881          * <2.20a of dwc3 have an issue with metastability (documented
2882          * elsewhere in this driver) which tells us we can't set max speed to
2883          * anything lower than SUPER.
2884          *
2885          * Because gadget.max_speed is only used by composite.c and function
2886          * drivers (i.e. it won't go into dwc3's registers) we are allowing this
2887          * to happen so we avoid sending SuperSpeed Capability descriptor
2888          * together with our BOS descriptor as that could confuse host into
2889          * thinking we can handle super speed.
2890          *
2891          * Note that, in fact, we won't even support GetBOS requests when speed
2892          * is less than super speed because we don't have means, yet, to tell
2893          * composite.c that we are USB 2.0 + LPM ECN.
2894          */
2895         if (dwc->revision < DWC3_REVISION_220A)
2896                 dwc3_trace(trace_dwc3_gadget,
2897                                 "Changing max_speed on rev %08x\n",
2898                                 dwc->revision);
2899
2900         dwc->gadget.max_speed           = dwc->maximum_speed;
2901
2902         /*
2903          * Per databook, DWC3 needs buffer size to be aligned to MaxPacketSize
2904          * on ep out.
2905          */
2906         dwc->gadget.quirk_ep_out_aligned_size = true;
2907
2908         /*
2909          * REVISIT: Here we should clear all pending IRQs to be
2910          * sure we're starting from a well known location.
2911          */
2912
2913         ret = dwc3_gadget_init_endpoints(dwc);
2914         if (ret)
2915                 goto err5;
2916
2917         ret = usb_add_gadget_udc(dwc->dev, &dwc->gadget);
2918         if (ret) {
2919                 dev_err(dwc->dev, "failed to register udc\n");
2920                 goto err5;
2921         }
2922
2923         return 0;
2924
2925 err5:
2926         kfree(dwc->zlp_buf);
2927
2928 err4:
2929         dwc3_gadget_free_endpoints(dwc);
2930         dma_free_coherent(dwc->dev, DWC3_EP0_BOUNCE_SIZE,
2931                         dwc->ep0_bounce, dwc->ep0_bounce_addr);
2932
2933 err3:
2934         kfree(dwc->setup_buf);
2935
2936 err2:
2937         dma_free_coherent(dwc->dev, sizeof(*dwc->ep0_trb),
2938                         dwc->ep0_trb, dwc->ep0_trb_addr);
2939
2940 err1:
2941         dma_free_coherent(dwc->dev, sizeof(*dwc->ctrl_req),
2942                         dwc->ctrl_req, dwc->ctrl_req_addr);
2943
2944 err0:
2945         return ret;
2946 }
2947
2948 /* -------------------------------------------------------------------------- */
2949
2950 void dwc3_gadget_exit(struct dwc3 *dwc)
2951 {
2952         usb_del_gadget_udc(&dwc->gadget);
2953
2954         dwc3_gadget_free_endpoints(dwc);
2955
2956         dma_free_coherent(dwc->dev, DWC3_EP0_BOUNCE_SIZE,
2957                         dwc->ep0_bounce, dwc->ep0_bounce_addr);
2958
2959         kfree(dwc->setup_buf);
2960         kfree(dwc->zlp_buf);
2961
2962         dma_free_coherent(dwc->dev, sizeof(*dwc->ep0_trb),
2963                         dwc->ep0_trb, dwc->ep0_trb_addr);
2964
2965         dma_free_coherent(dwc->dev, sizeof(*dwc->ctrl_req),
2966                         dwc->ctrl_req, dwc->ctrl_req_addr);
2967 }
2968
2969 int dwc3_gadget_suspend(struct dwc3 *dwc)
2970 {
2971         int ret;
2972
2973         if (!dwc->gadget_driver)
2974                 return 0;
2975
2976         ret = dwc3_gadget_run_stop(dwc, false, false);
2977         if (ret < 0)
2978                 return ret;
2979
2980         dwc3_disconnect_gadget(dwc);
2981         __dwc3_gadget_stop(dwc);
2982
2983         return 0;
2984 }
2985
2986 int dwc3_gadget_resume(struct dwc3 *dwc)
2987 {
2988         int                     ret;
2989
2990         if (!dwc->gadget_driver)
2991                 return 0;
2992
2993         ret = __dwc3_gadget_start(dwc);
2994         if (ret < 0)
2995                 goto err0;
2996
2997         ret = dwc3_gadget_run_stop(dwc, true, false);
2998         if (ret < 0)
2999                 goto err1;
3000
3001         return 0;
3002
3003 err1:
3004         __dwc3_gadget_stop(dwc);
3005
3006 err0:
3007         return ret;
3008 }