Merge branches 'acpi-sysfs', 'acpi-pci' and 'acpi-tables'
[cascardo/linux.git] / drivers / usb / chipidea / udc.c
1 /*
2  * udc.c - ChipIdea UDC driver
3  *
4  * Copyright (C) 2008 Chipidea - MIPS Technologies, Inc. All rights reserved.
5  *
6  * Author: David Lopo
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 as
10  * published by the Free Software Foundation.
11  */
12
13 #include <linux/delay.h>
14 #include <linux/device.h>
15 #include <linux/dmapool.h>
16 #include <linux/err.h>
17 #include <linux/irqreturn.h>
18 #include <linux/kernel.h>
19 #include <linux/slab.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/usb/ch9.h>
22 #include <linux/usb/gadget.h>
23 #include <linux/usb/otg-fsm.h>
24 #include <linux/usb/chipidea.h>
25
26 #include "ci.h"
27 #include "udc.h"
28 #include "bits.h"
29 #include "otg.h"
30 #include "otg_fsm.h"
31
32 /* control endpoint description */
33 static const struct usb_endpoint_descriptor
34 ctrl_endpt_out_desc = {
35         .bLength         = USB_DT_ENDPOINT_SIZE,
36         .bDescriptorType = USB_DT_ENDPOINT,
37
38         .bEndpointAddress = USB_DIR_OUT,
39         .bmAttributes    = USB_ENDPOINT_XFER_CONTROL,
40         .wMaxPacketSize  = cpu_to_le16(CTRL_PAYLOAD_MAX),
41 };
42
43 static const struct usb_endpoint_descriptor
44 ctrl_endpt_in_desc = {
45         .bLength         = USB_DT_ENDPOINT_SIZE,
46         .bDescriptorType = USB_DT_ENDPOINT,
47
48         .bEndpointAddress = USB_DIR_IN,
49         .bmAttributes    = USB_ENDPOINT_XFER_CONTROL,
50         .wMaxPacketSize  = cpu_to_le16(CTRL_PAYLOAD_MAX),
51 };
52
53 /**
54  * hw_ep_bit: calculates the bit number
55  * @num: endpoint number
56  * @dir: endpoint direction
57  *
58  * This function returns bit number
59  */
60 static inline int hw_ep_bit(int num, int dir)
61 {
62         return num + (dir ? 16 : 0);
63 }
64
65 static inline int ep_to_bit(struct ci_hdrc *ci, int n)
66 {
67         int fill = 16 - ci->hw_ep_max / 2;
68
69         if (n >= ci->hw_ep_max / 2)
70                 n += fill;
71
72         return n;
73 }
74
75 /**
76  * hw_device_state: enables/disables interrupts (execute without interruption)
77  * @dma: 0 => disable, !0 => enable and set dma engine
78  *
79  * This function returns an error code
80  */
81 static int hw_device_state(struct ci_hdrc *ci, u32 dma)
82 {
83         if (dma) {
84                 hw_write(ci, OP_ENDPTLISTADDR, ~0, dma);
85                 /* interrupt, error, port change, reset, sleep/suspend */
86                 hw_write(ci, OP_USBINTR, ~0,
87                              USBi_UI|USBi_UEI|USBi_PCI|USBi_URI|USBi_SLI);
88         } else {
89                 hw_write(ci, OP_USBINTR, ~0, 0);
90         }
91         return 0;
92 }
93
94 /**
95  * hw_ep_flush: flush endpoint fifo (execute without interruption)
96  * @num: endpoint number
97  * @dir: endpoint direction
98  *
99  * This function returns an error code
100  */
101 static int hw_ep_flush(struct ci_hdrc *ci, int num, int dir)
102 {
103         int n = hw_ep_bit(num, dir);
104
105         do {
106                 /* flush any pending transfer */
107                 hw_write(ci, OP_ENDPTFLUSH, ~0, BIT(n));
108                 while (hw_read(ci, OP_ENDPTFLUSH, BIT(n)))
109                         cpu_relax();
110         } while (hw_read(ci, OP_ENDPTSTAT, BIT(n)));
111
112         return 0;
113 }
114
115 /**
116  * hw_ep_disable: disables endpoint (execute without interruption)
117  * @num: endpoint number
118  * @dir: endpoint direction
119  *
120  * This function returns an error code
121  */
122 static int hw_ep_disable(struct ci_hdrc *ci, int num, int dir)
123 {
124         hw_ep_flush(ci, num, dir);
125         hw_write(ci, OP_ENDPTCTRL + num,
126                  dir ? ENDPTCTRL_TXE : ENDPTCTRL_RXE, 0);
127         return 0;
128 }
129
130 /**
131  * hw_ep_enable: enables endpoint (execute without interruption)
132  * @num:  endpoint number
133  * @dir:  endpoint direction
134  * @type: endpoint type
135  *
136  * This function returns an error code
137  */
138 static int hw_ep_enable(struct ci_hdrc *ci, int num, int dir, int type)
139 {
140         u32 mask, data;
141
142         if (dir) {
143                 mask  = ENDPTCTRL_TXT;  /* type    */
144                 data  = type << __ffs(mask);
145
146                 mask |= ENDPTCTRL_TXS;  /* unstall */
147                 mask |= ENDPTCTRL_TXR;  /* reset data toggle */
148                 data |= ENDPTCTRL_TXR;
149                 mask |= ENDPTCTRL_TXE;  /* enable  */
150                 data |= ENDPTCTRL_TXE;
151         } else {
152                 mask  = ENDPTCTRL_RXT;  /* type    */
153                 data  = type << __ffs(mask);
154
155                 mask |= ENDPTCTRL_RXS;  /* unstall */
156                 mask |= ENDPTCTRL_RXR;  /* reset data toggle */
157                 data |= ENDPTCTRL_RXR;
158                 mask |= ENDPTCTRL_RXE;  /* enable  */
159                 data |= ENDPTCTRL_RXE;
160         }
161         hw_write(ci, OP_ENDPTCTRL + num, mask, data);
162         return 0;
163 }
164
165 /**
166  * hw_ep_get_halt: return endpoint halt status
167  * @num: endpoint number
168  * @dir: endpoint direction
169  *
170  * This function returns 1 if endpoint halted
171  */
172 static int hw_ep_get_halt(struct ci_hdrc *ci, int num, int dir)
173 {
174         u32 mask = dir ? ENDPTCTRL_TXS : ENDPTCTRL_RXS;
175
176         return hw_read(ci, OP_ENDPTCTRL + num, mask) ? 1 : 0;
177 }
178
179 /**
180  * hw_ep_prime: primes endpoint (execute without interruption)
181  * @num:     endpoint number
182  * @dir:     endpoint direction
183  * @is_ctrl: true if control endpoint
184  *
185  * This function returns an error code
186  */
187 static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl)
188 {
189         int n = hw_ep_bit(num, dir);
190
191         if (is_ctrl && dir == RX && hw_read(ci, OP_ENDPTSETUPSTAT, BIT(num)))
192                 return -EAGAIN;
193
194         hw_write(ci, OP_ENDPTPRIME, ~0, BIT(n));
195
196         while (hw_read(ci, OP_ENDPTPRIME, BIT(n)))
197                 cpu_relax();
198         if (is_ctrl && dir == RX && hw_read(ci, OP_ENDPTSETUPSTAT, BIT(num)))
199                 return -EAGAIN;
200
201         /* status shoult be tested according with manual but it doesn't work */
202         return 0;
203 }
204
205 /**
206  * hw_ep_set_halt: configures ep halt & resets data toggle after clear (execute
207  *                 without interruption)
208  * @num:   endpoint number
209  * @dir:   endpoint direction
210  * @value: true => stall, false => unstall
211  *
212  * This function returns an error code
213  */
214 static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value)
215 {
216         if (value != 0 && value != 1)
217                 return -EINVAL;
218
219         do {
220                 enum ci_hw_regs reg = OP_ENDPTCTRL + num;
221                 u32 mask_xs = dir ? ENDPTCTRL_TXS : ENDPTCTRL_RXS;
222                 u32 mask_xr = dir ? ENDPTCTRL_TXR : ENDPTCTRL_RXR;
223
224                 /* data toggle - reserved for EP0 but it's in ESS */
225                 hw_write(ci, reg, mask_xs|mask_xr,
226                           value ? mask_xs : mask_xr);
227         } while (value != hw_ep_get_halt(ci, num, dir));
228
229         return 0;
230 }
231
232 /**
233  * hw_is_port_high_speed: test if port is high speed
234  *
235  * This function returns true if high speed port
236  */
237 static int hw_port_is_high_speed(struct ci_hdrc *ci)
238 {
239         return ci->hw_bank.lpm ? hw_read(ci, OP_DEVLC, DEVLC_PSPD) :
240                 hw_read(ci, OP_PORTSC, PORTSC_HSP);
241 }
242
243 /**
244  * hw_test_and_clear_complete: test & clear complete status (execute without
245  *                             interruption)
246  * @n: endpoint number
247  *
248  * This function returns complete status
249  */
250 static int hw_test_and_clear_complete(struct ci_hdrc *ci, int n)
251 {
252         n = ep_to_bit(ci, n);
253         return hw_test_and_clear(ci, OP_ENDPTCOMPLETE, BIT(n));
254 }
255
256 /**
257  * hw_test_and_clear_intr_active: test & clear active interrupts (execute
258  *                                without interruption)
259  *
260  * This function returns active interrutps
261  */
262 static u32 hw_test_and_clear_intr_active(struct ci_hdrc *ci)
263 {
264         u32 reg = hw_read_intr_status(ci) & hw_read_intr_enable(ci);
265
266         hw_write(ci, OP_USBSTS, ~0, reg);
267         return reg;
268 }
269
270 /**
271  * hw_test_and_clear_setup_guard: test & clear setup guard (execute without
272  *                                interruption)
273  *
274  * This function returns guard value
275  */
276 static int hw_test_and_clear_setup_guard(struct ci_hdrc *ci)
277 {
278         return hw_test_and_write(ci, OP_USBCMD, USBCMD_SUTW, 0);
279 }
280
281 /**
282  * hw_test_and_set_setup_guard: test & set setup guard (execute without
283  *                              interruption)
284  *
285  * This function returns guard value
286  */
287 static int hw_test_and_set_setup_guard(struct ci_hdrc *ci)
288 {
289         return hw_test_and_write(ci, OP_USBCMD, USBCMD_SUTW, USBCMD_SUTW);
290 }
291
292 /**
293  * hw_usb_set_address: configures USB address (execute without interruption)
294  * @value: new USB address
295  *
296  * This function explicitly sets the address, without the "USBADRA" (advance)
297  * feature, which is not supported by older versions of the controller.
298  */
299 static void hw_usb_set_address(struct ci_hdrc *ci, u8 value)
300 {
301         hw_write(ci, OP_DEVICEADDR, DEVICEADDR_USBADR,
302                  value << __ffs(DEVICEADDR_USBADR));
303 }
304
305 /**
306  * hw_usb_reset: restart device after a bus reset (execute without
307  *               interruption)
308  *
309  * This function returns an error code
310  */
311 static int hw_usb_reset(struct ci_hdrc *ci)
312 {
313         hw_usb_set_address(ci, 0);
314
315         /* ESS flushes only at end?!? */
316         hw_write(ci, OP_ENDPTFLUSH,    ~0, ~0);
317
318         /* clear setup token semaphores */
319         hw_write(ci, OP_ENDPTSETUPSTAT, 0,  0);
320
321         /* clear complete status */
322         hw_write(ci, OP_ENDPTCOMPLETE,  0,  0);
323
324         /* wait until all bits cleared */
325         while (hw_read(ci, OP_ENDPTPRIME, ~0))
326                 udelay(10);             /* not RTOS friendly */
327
328         /* reset all endpoints ? */
329
330         /* reset internal status and wait for further instructions
331            no need to verify the port reset status (ESS does it) */
332
333         return 0;
334 }
335
336 /******************************************************************************
337  * UTIL block
338  *****************************************************************************/
339
340 static int add_td_to_list(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq,
341                           unsigned length)
342 {
343         int i;
344         u32 temp;
345         struct td_node *lastnode, *node = kzalloc(sizeof(struct td_node),
346                                                   GFP_ATOMIC);
347
348         if (node == NULL)
349                 return -ENOMEM;
350
351         node->ptr = dma_pool_zalloc(hwep->td_pool, GFP_ATOMIC,
352                                    &node->dma);
353         if (node->ptr == NULL) {
354                 kfree(node);
355                 return -ENOMEM;
356         }
357
358         node->ptr->token = cpu_to_le32(length << __ffs(TD_TOTAL_BYTES));
359         node->ptr->token &= cpu_to_le32(TD_TOTAL_BYTES);
360         node->ptr->token |= cpu_to_le32(TD_STATUS_ACTIVE);
361         if (hwep->type == USB_ENDPOINT_XFER_ISOC && hwep->dir == TX) {
362                 u32 mul = hwreq->req.length / hwep->ep.maxpacket;
363
364                 if (hwreq->req.length == 0
365                                 || hwreq->req.length % hwep->ep.maxpacket)
366                         mul++;
367                 node->ptr->token |= mul << __ffs(TD_MULTO);
368         }
369
370         temp = (u32) (hwreq->req.dma + hwreq->req.actual);
371         if (length) {
372                 node->ptr->page[0] = cpu_to_le32(temp);
373                 for (i = 1; i < TD_PAGE_COUNT; i++) {
374                         u32 page = temp + i * CI_HDRC_PAGE_SIZE;
375                         page &= ~TD_RESERVED_MASK;
376                         node->ptr->page[i] = cpu_to_le32(page);
377                 }
378         }
379
380         hwreq->req.actual += length;
381
382         if (!list_empty(&hwreq->tds)) {
383                 /* get the last entry */
384                 lastnode = list_entry(hwreq->tds.prev,
385                                 struct td_node, td);
386                 lastnode->ptr->next = cpu_to_le32(node->dma);
387         }
388
389         INIT_LIST_HEAD(&node->td);
390         list_add_tail(&node->td, &hwreq->tds);
391
392         return 0;
393 }
394
395 /**
396  * _usb_addr: calculates endpoint address from direction & number
397  * @ep:  endpoint
398  */
399 static inline u8 _usb_addr(struct ci_hw_ep *ep)
400 {
401         return ((ep->dir == TX) ? USB_ENDPOINT_DIR_MASK : 0) | ep->num;
402 }
403
404 /**
405  * _hardware_enqueue: configures a request at hardware level
406  * @hwep:   endpoint
407  * @hwreq:  request
408  *
409  * This function returns an error code
410  */
411 static int _hardware_enqueue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
412 {
413         struct ci_hdrc *ci = hwep->ci;
414         int ret = 0;
415         unsigned rest = hwreq->req.length;
416         int pages = TD_PAGE_COUNT;
417         struct td_node *firstnode, *lastnode;
418
419         /* don't queue twice */
420         if (hwreq->req.status == -EALREADY)
421                 return -EALREADY;
422
423         hwreq->req.status = -EALREADY;
424
425         ret = usb_gadget_map_request(&ci->gadget, &hwreq->req, hwep->dir);
426         if (ret)
427                 return ret;
428
429         /*
430          * The first buffer could be not page aligned.
431          * In that case we have to span into one extra td.
432          */
433         if (hwreq->req.dma % PAGE_SIZE)
434                 pages--;
435
436         if (rest == 0) {
437                 ret = add_td_to_list(hwep, hwreq, 0);
438                 if (ret < 0)
439                         goto done;
440         }
441
442         while (rest > 0) {
443                 unsigned count = min(hwreq->req.length - hwreq->req.actual,
444                                         (unsigned)(pages * CI_HDRC_PAGE_SIZE));
445                 ret = add_td_to_list(hwep, hwreq, count);
446                 if (ret < 0)
447                         goto done;
448
449                 rest -= count;
450         }
451
452         if (hwreq->req.zero && hwreq->req.length && hwep->dir == TX
453             && (hwreq->req.length % hwep->ep.maxpacket == 0)) {
454                 ret = add_td_to_list(hwep, hwreq, 0);
455                 if (ret < 0)
456                         goto done;
457         }
458
459         firstnode = list_first_entry(&hwreq->tds, struct td_node, td);
460
461         lastnode = list_entry(hwreq->tds.prev,
462                 struct td_node, td);
463
464         lastnode->ptr->next = cpu_to_le32(TD_TERMINATE);
465         if (!hwreq->req.no_interrupt)
466                 lastnode->ptr->token |= cpu_to_le32(TD_IOC);
467         wmb();
468
469         hwreq->req.actual = 0;
470         if (!list_empty(&hwep->qh.queue)) {
471                 struct ci_hw_req *hwreqprev;
472                 int n = hw_ep_bit(hwep->num, hwep->dir);
473                 int tmp_stat;
474                 struct td_node *prevlastnode;
475                 u32 next = firstnode->dma & TD_ADDR_MASK;
476
477                 hwreqprev = list_entry(hwep->qh.queue.prev,
478                                 struct ci_hw_req, queue);
479                 prevlastnode = list_entry(hwreqprev->tds.prev,
480                                 struct td_node, td);
481
482                 prevlastnode->ptr->next = cpu_to_le32(next);
483                 wmb();
484                 if (hw_read(ci, OP_ENDPTPRIME, BIT(n)))
485                         goto done;
486                 do {
487                         hw_write(ci, OP_USBCMD, USBCMD_ATDTW, USBCMD_ATDTW);
488                         tmp_stat = hw_read(ci, OP_ENDPTSTAT, BIT(n));
489                 } while (!hw_read(ci, OP_USBCMD, USBCMD_ATDTW));
490                 hw_write(ci, OP_USBCMD, USBCMD_ATDTW, 0);
491                 if (tmp_stat)
492                         goto done;
493         }
494
495         /*  QH configuration */
496         hwep->qh.ptr->td.next = cpu_to_le32(firstnode->dma);
497         hwep->qh.ptr->td.token &=
498                 cpu_to_le32(~(TD_STATUS_HALTED|TD_STATUS_ACTIVE));
499
500         if (hwep->type == USB_ENDPOINT_XFER_ISOC && hwep->dir == RX) {
501                 u32 mul = hwreq->req.length / hwep->ep.maxpacket;
502
503                 if (hwreq->req.length == 0
504                                 || hwreq->req.length % hwep->ep.maxpacket)
505                         mul++;
506                 hwep->qh.ptr->cap |= mul << __ffs(QH_MULT);
507         }
508
509         wmb();   /* synchronize before ep prime */
510
511         ret = hw_ep_prime(ci, hwep->num, hwep->dir,
512                            hwep->type == USB_ENDPOINT_XFER_CONTROL);
513 done:
514         return ret;
515 }
516
517 /*
518  * free_pending_td: remove a pending request for the endpoint
519  * @hwep: endpoint
520  */
521 static void free_pending_td(struct ci_hw_ep *hwep)
522 {
523         struct td_node *pending = hwep->pending_td;
524
525         dma_pool_free(hwep->td_pool, pending->ptr, pending->dma);
526         hwep->pending_td = NULL;
527         kfree(pending);
528 }
529
530 static int reprime_dtd(struct ci_hdrc *ci, struct ci_hw_ep *hwep,
531                                            struct td_node *node)
532 {
533         hwep->qh.ptr->td.next = node->dma;
534         hwep->qh.ptr->td.token &=
535                 cpu_to_le32(~(TD_STATUS_HALTED | TD_STATUS_ACTIVE));
536
537         /* Synchronize before ep prime */
538         wmb();
539
540         return hw_ep_prime(ci, hwep->num, hwep->dir,
541                                 hwep->type == USB_ENDPOINT_XFER_CONTROL);
542 }
543
544 /**
545  * _hardware_dequeue: handles a request at hardware level
546  * @gadget: gadget
547  * @hwep:   endpoint
548  *
549  * This function returns an error code
550  */
551 static int _hardware_dequeue(struct ci_hw_ep *hwep, struct ci_hw_req *hwreq)
552 {
553         u32 tmptoken;
554         struct td_node *node, *tmpnode;
555         unsigned remaining_length;
556         unsigned actual = hwreq->req.length;
557         struct ci_hdrc *ci = hwep->ci;
558
559         if (hwreq->req.status != -EALREADY)
560                 return -EINVAL;
561
562         hwreq->req.status = 0;
563
564         list_for_each_entry_safe(node, tmpnode, &hwreq->tds, td) {
565                 tmptoken = le32_to_cpu(node->ptr->token);
566                 if ((TD_STATUS_ACTIVE & tmptoken) != 0) {
567                         int n = hw_ep_bit(hwep->num, hwep->dir);
568
569                         if (ci->rev == CI_REVISION_24)
570                                 if (!hw_read(ci, OP_ENDPTSTAT, BIT(n)))
571                                         reprime_dtd(ci, hwep, node);
572                         hwreq->req.status = -EALREADY;
573                         return -EBUSY;
574                 }
575
576                 remaining_length = (tmptoken & TD_TOTAL_BYTES);
577                 remaining_length >>= __ffs(TD_TOTAL_BYTES);
578                 actual -= remaining_length;
579
580                 hwreq->req.status = tmptoken & TD_STATUS;
581                 if ((TD_STATUS_HALTED & hwreq->req.status)) {
582                         hwreq->req.status = -EPIPE;
583                         break;
584                 } else if ((TD_STATUS_DT_ERR & hwreq->req.status)) {
585                         hwreq->req.status = -EPROTO;
586                         break;
587                 } else if ((TD_STATUS_TR_ERR & hwreq->req.status)) {
588                         hwreq->req.status = -EILSEQ;
589                         break;
590                 }
591
592                 if (remaining_length) {
593                         if (hwep->dir) {
594                                 hwreq->req.status = -EPROTO;
595                                 break;
596                         }
597                 }
598                 /*
599                  * As the hardware could still address the freed td
600                  * which will run the udc unusable, the cleanup of the
601                  * td has to be delayed by one.
602                  */
603                 if (hwep->pending_td)
604                         free_pending_td(hwep);
605
606                 hwep->pending_td = node;
607                 list_del_init(&node->td);
608         }
609
610         usb_gadget_unmap_request(&hwep->ci->gadget, &hwreq->req, hwep->dir);
611
612         hwreq->req.actual += actual;
613
614         if (hwreq->req.status)
615                 return hwreq->req.status;
616
617         return hwreq->req.actual;
618 }
619
620 /**
621  * _ep_nuke: dequeues all endpoint requests
622  * @hwep: endpoint
623  *
624  * This function returns an error code
625  * Caller must hold lock
626  */
627 static int _ep_nuke(struct ci_hw_ep *hwep)
628 __releases(hwep->lock)
629 __acquires(hwep->lock)
630 {
631         struct td_node *node, *tmpnode;
632         if (hwep == NULL)
633                 return -EINVAL;
634
635         hw_ep_flush(hwep->ci, hwep->num, hwep->dir);
636
637         while (!list_empty(&hwep->qh.queue)) {
638
639                 /* pop oldest request */
640                 struct ci_hw_req *hwreq = list_entry(hwep->qh.queue.next,
641                                                      struct ci_hw_req, queue);
642
643                 list_for_each_entry_safe(node, tmpnode, &hwreq->tds, td) {
644                         dma_pool_free(hwep->td_pool, node->ptr, node->dma);
645                         list_del_init(&node->td);
646                         node->ptr = NULL;
647                         kfree(node);
648                 }
649
650                 list_del_init(&hwreq->queue);
651                 hwreq->req.status = -ESHUTDOWN;
652
653                 if (hwreq->req.complete != NULL) {
654                         spin_unlock(hwep->lock);
655                         usb_gadget_giveback_request(&hwep->ep, &hwreq->req);
656                         spin_lock(hwep->lock);
657                 }
658         }
659
660         if (hwep->pending_td)
661                 free_pending_td(hwep);
662
663         return 0;
664 }
665
666 static int _ep_set_halt(struct usb_ep *ep, int value, bool check_transfer)
667 {
668         struct ci_hw_ep *hwep = container_of(ep, struct ci_hw_ep, ep);
669         int direction, retval = 0;
670         unsigned long flags;
671
672         if (ep == NULL || hwep->ep.desc == NULL)
673                 return -EINVAL;
674
675         if (usb_endpoint_xfer_isoc(hwep->ep.desc))
676                 return -EOPNOTSUPP;
677
678         spin_lock_irqsave(hwep->lock, flags);
679
680         if (value && hwep->dir == TX && check_transfer &&
681                 !list_empty(&hwep->qh.queue) &&
682                         !usb_endpoint_xfer_control(hwep->ep.desc)) {
683                 spin_unlock_irqrestore(hwep->lock, flags);
684                 return -EAGAIN;
685         }
686
687         direction = hwep->dir;
688         do {
689                 retval |= hw_ep_set_halt(hwep->ci, hwep->num, hwep->dir, value);
690
691                 if (!value)
692                         hwep->wedge = 0;
693
694                 if (hwep->type == USB_ENDPOINT_XFER_CONTROL)
695                         hwep->dir = (hwep->dir == TX) ? RX : TX;
696
697         } while (hwep->dir != direction);
698
699         spin_unlock_irqrestore(hwep->lock, flags);
700         return retval;
701 }
702
703
704 /**
705  * _gadget_stop_activity: stops all USB activity, flushes & disables all endpts
706  * @gadget: gadget
707  *
708  * This function returns an error code
709  */
710 static int _gadget_stop_activity(struct usb_gadget *gadget)
711 {
712         struct usb_ep *ep;
713         struct ci_hdrc    *ci = container_of(gadget, struct ci_hdrc, gadget);
714         unsigned long flags;
715
716         spin_lock_irqsave(&ci->lock, flags);
717         ci->gadget.speed = USB_SPEED_UNKNOWN;
718         ci->remote_wakeup = 0;
719         ci->suspended = 0;
720         spin_unlock_irqrestore(&ci->lock, flags);
721
722         /* flush all endpoints */
723         gadget_for_each_ep(ep, gadget) {
724                 usb_ep_fifo_flush(ep);
725         }
726         usb_ep_fifo_flush(&ci->ep0out->ep);
727         usb_ep_fifo_flush(&ci->ep0in->ep);
728
729         /* make sure to disable all endpoints */
730         gadget_for_each_ep(ep, gadget) {
731                 usb_ep_disable(ep);
732         }
733
734         if (ci->status != NULL) {
735                 usb_ep_free_request(&ci->ep0in->ep, ci->status);
736                 ci->status = NULL;
737         }
738
739         return 0;
740 }
741
742 /******************************************************************************
743  * ISR block
744  *****************************************************************************/
745 /**
746  * isr_reset_handler: USB reset interrupt handler
747  * @ci: UDC device
748  *
749  * This function resets USB engine after a bus reset occurred
750  */
751 static void isr_reset_handler(struct ci_hdrc *ci)
752 __releases(ci->lock)
753 __acquires(ci->lock)
754 {
755         int retval;
756
757         spin_unlock(&ci->lock);
758         if (ci->gadget.speed != USB_SPEED_UNKNOWN)
759                 usb_gadget_udc_reset(&ci->gadget, ci->driver);
760
761         retval = _gadget_stop_activity(&ci->gadget);
762         if (retval)
763                 goto done;
764
765         retval = hw_usb_reset(ci);
766         if (retval)
767                 goto done;
768
769         ci->status = usb_ep_alloc_request(&ci->ep0in->ep, GFP_ATOMIC);
770         if (ci->status == NULL)
771                 retval = -ENOMEM;
772
773 done:
774         spin_lock(&ci->lock);
775
776         if (retval)
777                 dev_err(ci->dev, "error: %i\n", retval);
778 }
779
780 /**
781  * isr_get_status_complete: get_status request complete function
782  * @ep:  endpoint
783  * @req: request handled
784  *
785  * Caller must release lock
786  */
787 static void isr_get_status_complete(struct usb_ep *ep, struct usb_request *req)
788 {
789         if (ep == NULL || req == NULL)
790                 return;
791
792         kfree(req->buf);
793         usb_ep_free_request(ep, req);
794 }
795
796 /**
797  * _ep_queue: queues (submits) an I/O request to an endpoint
798  * @ep:        endpoint
799  * @req:       request
800  * @gfp_flags: GFP flags (not used)
801  *
802  * Caller must hold lock
803  * This function returns an error code
804  */
805 static int _ep_queue(struct usb_ep *ep, struct usb_request *req,
806                     gfp_t __maybe_unused gfp_flags)
807 {
808         struct ci_hw_ep  *hwep  = container_of(ep,  struct ci_hw_ep, ep);
809         struct ci_hw_req *hwreq = container_of(req, struct ci_hw_req, req);
810         struct ci_hdrc *ci = hwep->ci;
811         int retval = 0;
812
813         if (ep == NULL || req == NULL || hwep->ep.desc == NULL)
814                 return -EINVAL;
815
816         if (hwep->type == USB_ENDPOINT_XFER_CONTROL) {
817                 if (req->length)
818                         hwep = (ci->ep0_dir == RX) ?
819                                ci->ep0out : ci->ep0in;
820                 if (!list_empty(&hwep->qh.queue)) {
821                         _ep_nuke(hwep);
822                         dev_warn(hwep->ci->dev, "endpoint ctrl %X nuked\n",
823                                  _usb_addr(hwep));
824                 }
825         }
826
827         if (usb_endpoint_xfer_isoc(hwep->ep.desc) &&
828             hwreq->req.length > (1 + hwep->ep.mult) * hwep->ep.maxpacket) {
829                 dev_err(hwep->ci->dev, "request length too big for isochronous\n");
830                 return -EMSGSIZE;
831         }
832
833         /* first nuke then test link, e.g. previous status has not sent */
834         if (!list_empty(&hwreq->queue)) {
835                 dev_err(hwep->ci->dev, "request already in queue\n");
836                 return -EBUSY;
837         }
838
839         /* push request */
840         hwreq->req.status = -EINPROGRESS;
841         hwreq->req.actual = 0;
842
843         retval = _hardware_enqueue(hwep, hwreq);
844
845         if (retval == -EALREADY)
846                 retval = 0;
847         if (!retval)
848                 list_add_tail(&hwreq->queue, &hwep->qh.queue);
849
850         return retval;
851 }
852
853 /**
854  * isr_get_status_response: get_status request response
855  * @ci: ci struct
856  * @setup: setup request packet
857  *
858  * This function returns an error code
859  */
860 static int isr_get_status_response(struct ci_hdrc *ci,
861                                    struct usb_ctrlrequest *setup)
862 __releases(hwep->lock)
863 __acquires(hwep->lock)
864 {
865         struct ci_hw_ep *hwep = ci->ep0in;
866         struct usb_request *req = NULL;
867         gfp_t gfp_flags = GFP_ATOMIC;
868         int dir, num, retval;
869
870         if (hwep == NULL || setup == NULL)
871                 return -EINVAL;
872
873         spin_unlock(hwep->lock);
874         req = usb_ep_alloc_request(&hwep->ep, gfp_flags);
875         spin_lock(hwep->lock);
876         if (req == NULL)
877                 return -ENOMEM;
878
879         req->complete = isr_get_status_complete;
880         req->length   = 2;
881         req->buf      = kzalloc(req->length, gfp_flags);
882         if (req->buf == NULL) {
883                 retval = -ENOMEM;
884                 goto err_free_req;
885         }
886
887         if ((setup->bRequestType & USB_RECIP_MASK) == USB_RECIP_DEVICE) {
888                 *(u16 *)req->buf = (ci->remote_wakeup << 1) |
889                         ci->gadget.is_selfpowered;
890         } else if ((setup->bRequestType & USB_RECIP_MASK) \
891                    == USB_RECIP_ENDPOINT) {
892                 dir = (le16_to_cpu(setup->wIndex) & USB_ENDPOINT_DIR_MASK) ?
893                         TX : RX;
894                 num =  le16_to_cpu(setup->wIndex) & USB_ENDPOINT_NUMBER_MASK;
895                 *(u16 *)req->buf = hw_ep_get_halt(ci, num, dir);
896         }
897         /* else do nothing; reserved for future use */
898
899         retval = _ep_queue(&hwep->ep, req, gfp_flags);
900         if (retval)
901                 goto err_free_buf;
902
903         return 0;
904
905  err_free_buf:
906         kfree(req->buf);
907  err_free_req:
908         spin_unlock(hwep->lock);
909         usb_ep_free_request(&hwep->ep, req);
910         spin_lock(hwep->lock);
911         return retval;
912 }
913
914 /**
915  * isr_setup_status_complete: setup_status request complete function
916  * @ep:  endpoint
917  * @req: request handled
918  *
919  * Caller must release lock. Put the port in test mode if test mode
920  * feature is selected.
921  */
922 static void
923 isr_setup_status_complete(struct usb_ep *ep, struct usb_request *req)
924 {
925         struct ci_hdrc *ci = req->context;
926         unsigned long flags;
927
928         if (ci->setaddr) {
929                 hw_usb_set_address(ci, ci->address);
930                 ci->setaddr = false;
931                 if (ci->address)
932                         usb_gadget_set_state(&ci->gadget, USB_STATE_ADDRESS);
933         }
934
935         spin_lock_irqsave(&ci->lock, flags);
936         if (ci->test_mode)
937                 hw_port_test_set(ci, ci->test_mode);
938         spin_unlock_irqrestore(&ci->lock, flags);
939 }
940
941 /**
942  * isr_setup_status_phase: queues the status phase of a setup transation
943  * @ci: ci struct
944  *
945  * This function returns an error code
946  */
947 static int isr_setup_status_phase(struct ci_hdrc *ci)
948 {
949         int retval;
950         struct ci_hw_ep *hwep;
951
952         /*
953          * Unexpected USB controller behavior, caused by bad signal integrity
954          * or ground reference problems, can lead to isr_setup_status_phase
955          * being called with ci->status equal to NULL.
956          * If this situation occurs, you should review your USB hardware design.
957          */
958         if (WARN_ON_ONCE(!ci->status))
959                 return -EPIPE;
960
961         hwep = (ci->ep0_dir == TX) ? ci->ep0out : ci->ep0in;
962         ci->status->context = ci;
963         ci->status->complete = isr_setup_status_complete;
964
965         retval = _ep_queue(&hwep->ep, ci->status, GFP_ATOMIC);
966
967         return retval;
968 }
969
970 /**
971  * isr_tr_complete_low: transaction complete low level handler
972  * @hwep: endpoint
973  *
974  * This function returns an error code
975  * Caller must hold lock
976  */
977 static int isr_tr_complete_low(struct ci_hw_ep *hwep)
978 __releases(hwep->lock)
979 __acquires(hwep->lock)
980 {
981         struct ci_hw_req *hwreq, *hwreqtemp;
982         struct ci_hw_ep *hweptemp = hwep;
983         int retval = 0;
984
985         list_for_each_entry_safe(hwreq, hwreqtemp, &hwep->qh.queue,
986                         queue) {
987                 retval = _hardware_dequeue(hwep, hwreq);
988                 if (retval < 0)
989                         break;
990                 list_del_init(&hwreq->queue);
991                 if (hwreq->req.complete != NULL) {
992                         spin_unlock(hwep->lock);
993                         if ((hwep->type == USB_ENDPOINT_XFER_CONTROL) &&
994                                         hwreq->req.length)
995                                 hweptemp = hwep->ci->ep0in;
996                         usb_gadget_giveback_request(&hweptemp->ep, &hwreq->req);
997                         spin_lock(hwep->lock);
998                 }
999         }
1000
1001         if (retval == -EBUSY)
1002                 retval = 0;
1003
1004         return retval;
1005 }
1006
1007 static int otg_a_alt_hnp_support(struct ci_hdrc *ci)
1008 {
1009         dev_warn(&ci->gadget.dev,
1010                 "connect the device to an alternate port if you want HNP\n");
1011         return isr_setup_status_phase(ci);
1012 }
1013
1014 /**
1015  * isr_setup_packet_handler: setup packet handler
1016  * @ci: UDC descriptor
1017  *
1018  * This function handles setup packet 
1019  */
1020 static void isr_setup_packet_handler(struct ci_hdrc *ci)
1021 __releases(ci->lock)
1022 __acquires(ci->lock)
1023 {
1024         struct ci_hw_ep *hwep = &ci->ci_hw_ep[0];
1025         struct usb_ctrlrequest req;
1026         int type, num, dir, err = -EINVAL;
1027         u8 tmode = 0;
1028
1029         /*
1030          * Flush data and handshake transactions of previous
1031          * setup packet.
1032          */
1033         _ep_nuke(ci->ep0out);
1034         _ep_nuke(ci->ep0in);
1035
1036         /* read_setup_packet */
1037         do {
1038                 hw_test_and_set_setup_guard(ci);
1039                 memcpy(&req, &hwep->qh.ptr->setup, sizeof(req));
1040         } while (!hw_test_and_clear_setup_guard(ci));
1041
1042         type = req.bRequestType;
1043
1044         ci->ep0_dir = (type & USB_DIR_IN) ? TX : RX;
1045
1046         switch (req.bRequest) {
1047         case USB_REQ_CLEAR_FEATURE:
1048                 if (type == (USB_DIR_OUT|USB_RECIP_ENDPOINT) &&
1049                                 le16_to_cpu(req.wValue) ==
1050                                 USB_ENDPOINT_HALT) {
1051                         if (req.wLength != 0)
1052                                 break;
1053                         num  = le16_to_cpu(req.wIndex);
1054                         dir = num & USB_ENDPOINT_DIR_MASK;
1055                         num &= USB_ENDPOINT_NUMBER_MASK;
1056                         if (dir) /* TX */
1057                                 num += ci->hw_ep_max / 2;
1058                         if (!ci->ci_hw_ep[num].wedge) {
1059                                 spin_unlock(&ci->lock);
1060                                 err = usb_ep_clear_halt(
1061                                         &ci->ci_hw_ep[num].ep);
1062                                 spin_lock(&ci->lock);
1063                                 if (err)
1064                                         break;
1065                         }
1066                         err = isr_setup_status_phase(ci);
1067                 } else if (type == (USB_DIR_OUT|USB_RECIP_DEVICE) &&
1068                                 le16_to_cpu(req.wValue) ==
1069                                 USB_DEVICE_REMOTE_WAKEUP) {
1070                         if (req.wLength != 0)
1071                                 break;
1072                         ci->remote_wakeup = 0;
1073                         err = isr_setup_status_phase(ci);
1074                 } else {
1075                         goto delegate;
1076                 }
1077                 break;
1078         case USB_REQ_GET_STATUS:
1079                 if ((type != (USB_DIR_IN|USB_RECIP_DEVICE) ||
1080                         le16_to_cpu(req.wIndex) == OTG_STS_SELECTOR) &&
1081                     type != (USB_DIR_IN|USB_RECIP_ENDPOINT) &&
1082                     type != (USB_DIR_IN|USB_RECIP_INTERFACE))
1083                         goto delegate;
1084                 if (le16_to_cpu(req.wLength) != 2 ||
1085                     le16_to_cpu(req.wValue)  != 0)
1086                         break;
1087                 err = isr_get_status_response(ci, &req);
1088                 break;
1089         case USB_REQ_SET_ADDRESS:
1090                 if (type != (USB_DIR_OUT|USB_RECIP_DEVICE))
1091                         goto delegate;
1092                 if (le16_to_cpu(req.wLength) != 0 ||
1093                     le16_to_cpu(req.wIndex)  != 0)
1094                         break;
1095                 ci->address = (u8)le16_to_cpu(req.wValue);
1096                 ci->setaddr = true;
1097                 err = isr_setup_status_phase(ci);
1098                 break;
1099         case USB_REQ_SET_FEATURE:
1100                 if (type == (USB_DIR_OUT|USB_RECIP_ENDPOINT) &&
1101                                 le16_to_cpu(req.wValue) ==
1102                                 USB_ENDPOINT_HALT) {
1103                         if (req.wLength != 0)
1104                                 break;
1105                         num  = le16_to_cpu(req.wIndex);
1106                         dir = num & USB_ENDPOINT_DIR_MASK;
1107                         num &= USB_ENDPOINT_NUMBER_MASK;
1108                         if (dir) /* TX */
1109                                 num += ci->hw_ep_max / 2;
1110
1111                         spin_unlock(&ci->lock);
1112                         err = _ep_set_halt(&ci->ci_hw_ep[num].ep, 1, false);
1113                         spin_lock(&ci->lock);
1114                         if (!err)
1115                                 isr_setup_status_phase(ci);
1116                 } else if (type == (USB_DIR_OUT|USB_RECIP_DEVICE)) {
1117                         if (req.wLength != 0)
1118                                 break;
1119                         switch (le16_to_cpu(req.wValue)) {
1120                         case USB_DEVICE_REMOTE_WAKEUP:
1121                                 ci->remote_wakeup = 1;
1122                                 err = isr_setup_status_phase(ci);
1123                                 break;
1124                         case USB_DEVICE_TEST_MODE:
1125                                 tmode = le16_to_cpu(req.wIndex) >> 8;
1126                                 switch (tmode) {
1127                                 case TEST_J:
1128                                 case TEST_K:
1129                                 case TEST_SE0_NAK:
1130                                 case TEST_PACKET:
1131                                 case TEST_FORCE_EN:
1132                                         ci->test_mode = tmode;
1133                                         err = isr_setup_status_phase(
1134                                                         ci);
1135                                         break;
1136                                 default:
1137                                         break;
1138                                 }
1139                                 break;
1140                         case USB_DEVICE_B_HNP_ENABLE:
1141                                 if (ci_otg_is_fsm_mode(ci)) {
1142                                         ci->gadget.b_hnp_enable = 1;
1143                                         err = isr_setup_status_phase(
1144                                                         ci);
1145                                 }
1146                                 break;
1147                         case USB_DEVICE_A_ALT_HNP_SUPPORT:
1148                                 if (ci_otg_is_fsm_mode(ci))
1149                                         err = otg_a_alt_hnp_support(ci);
1150                                 break;
1151                         case USB_DEVICE_A_HNP_SUPPORT:
1152                                 if (ci_otg_is_fsm_mode(ci)) {
1153                                         ci->gadget.a_hnp_support = 1;
1154                                         err = isr_setup_status_phase(
1155                                                         ci);
1156                                 }
1157                                 break;
1158                         default:
1159                                 goto delegate;
1160                         }
1161                 } else {
1162                         goto delegate;
1163                 }
1164                 break;
1165         default:
1166 delegate:
1167                 if (req.wLength == 0)   /* no data phase */
1168                         ci->ep0_dir = TX;
1169
1170                 spin_unlock(&ci->lock);
1171                 err = ci->driver->setup(&ci->gadget, &req);
1172                 spin_lock(&ci->lock);
1173                 break;
1174         }
1175
1176         if (err < 0) {
1177                 spin_unlock(&ci->lock);
1178                 if (_ep_set_halt(&hwep->ep, 1, false))
1179                         dev_err(ci->dev, "error: _ep_set_halt\n");
1180                 spin_lock(&ci->lock);
1181         }
1182 }
1183
1184 /**
1185  * isr_tr_complete_handler: transaction complete interrupt handler
1186  * @ci: UDC descriptor
1187  *
1188  * This function handles traffic events
1189  */
1190 static void isr_tr_complete_handler(struct ci_hdrc *ci)
1191 __releases(ci->lock)
1192 __acquires(ci->lock)
1193 {
1194         unsigned i;
1195         int err;
1196
1197         for (i = 0; i < ci->hw_ep_max; i++) {
1198                 struct ci_hw_ep *hwep  = &ci->ci_hw_ep[i];
1199
1200                 if (hwep->ep.desc == NULL)
1201                         continue;   /* not configured */
1202
1203                 if (hw_test_and_clear_complete(ci, i)) {
1204                         err = isr_tr_complete_low(hwep);
1205                         if (hwep->type == USB_ENDPOINT_XFER_CONTROL) {
1206                                 if (err > 0)   /* needs status phase */
1207                                         err = isr_setup_status_phase(ci);
1208                                 if (err < 0) {
1209                                         spin_unlock(&ci->lock);
1210                                         if (_ep_set_halt(&hwep->ep, 1, false))
1211                                                 dev_err(ci->dev,
1212                                                 "error: _ep_set_halt\n");
1213                                         spin_lock(&ci->lock);
1214                                 }
1215                         }
1216                 }
1217
1218                 /* Only handle setup packet below */
1219                 if (i == 0 &&
1220                         hw_test_and_clear(ci, OP_ENDPTSETUPSTAT, BIT(0)))
1221                         isr_setup_packet_handler(ci);
1222         }
1223 }
1224
1225 /******************************************************************************
1226  * ENDPT block
1227  *****************************************************************************/
1228 /**
1229  * ep_enable: configure endpoint, making it usable
1230  *
1231  * Check usb_ep_enable() at "usb_gadget.h" for details
1232  */
1233 static int ep_enable(struct usb_ep *ep,
1234                      const struct usb_endpoint_descriptor *desc)
1235 {
1236         struct ci_hw_ep *hwep = container_of(ep, struct ci_hw_ep, ep);
1237         int retval = 0;
1238         unsigned long flags;
1239         u32 cap = 0;
1240
1241         if (ep == NULL || desc == NULL)
1242                 return -EINVAL;
1243
1244         spin_lock_irqsave(hwep->lock, flags);
1245
1246         /* only internal SW should enable ctrl endpts */
1247
1248         if (!list_empty(&hwep->qh.queue)) {
1249                 dev_warn(hwep->ci->dev, "enabling a non-empty endpoint!\n");
1250                 spin_unlock_irqrestore(hwep->lock, flags);
1251                 return -EBUSY;
1252         }
1253
1254         hwep->ep.desc = desc;
1255
1256         hwep->dir  = usb_endpoint_dir_in(desc) ? TX : RX;
1257         hwep->num  = usb_endpoint_num(desc);
1258         hwep->type = usb_endpoint_type(desc);
1259
1260         hwep->ep.maxpacket = usb_endpoint_maxp(desc) & 0x07ff;
1261         hwep->ep.mult = QH_ISO_MULT(usb_endpoint_maxp(desc));
1262
1263         if (hwep->type == USB_ENDPOINT_XFER_CONTROL)
1264                 cap |= QH_IOS;
1265
1266         cap |= QH_ZLT;
1267         cap |= (hwep->ep.maxpacket << __ffs(QH_MAX_PKT)) & QH_MAX_PKT;
1268         /*
1269          * For ISO-TX, we set mult at QH as the largest value, and use
1270          * MultO at TD as real mult value.
1271          */
1272         if (hwep->type == USB_ENDPOINT_XFER_ISOC && hwep->dir == TX)
1273                 cap |= 3 << __ffs(QH_MULT);
1274
1275         hwep->qh.ptr->cap = cpu_to_le32(cap);
1276
1277         hwep->qh.ptr->td.next |= cpu_to_le32(TD_TERMINATE);   /* needed? */
1278
1279         if (hwep->num != 0 && hwep->type == USB_ENDPOINT_XFER_CONTROL) {
1280                 dev_err(hwep->ci->dev, "Set control xfer at non-ep0\n");
1281                 retval = -EINVAL;
1282         }
1283
1284         /*
1285          * Enable endpoints in the HW other than ep0 as ep0
1286          * is always enabled
1287          */
1288         if (hwep->num)
1289                 retval |= hw_ep_enable(hwep->ci, hwep->num, hwep->dir,
1290                                        hwep->type);
1291
1292         spin_unlock_irqrestore(hwep->lock, flags);
1293         return retval;
1294 }
1295
1296 /**
1297  * ep_disable: endpoint is no longer usable
1298  *
1299  * Check usb_ep_disable() at "usb_gadget.h" for details
1300  */
1301 static int ep_disable(struct usb_ep *ep)
1302 {
1303         struct ci_hw_ep *hwep = container_of(ep, struct ci_hw_ep, ep);
1304         int direction, retval = 0;
1305         unsigned long flags;
1306
1307         if (ep == NULL)
1308                 return -EINVAL;
1309         else if (hwep->ep.desc == NULL)
1310                 return -EBUSY;
1311
1312         spin_lock_irqsave(hwep->lock, flags);
1313
1314         /* only internal SW should disable ctrl endpts */
1315
1316         direction = hwep->dir;
1317         do {
1318                 retval |= _ep_nuke(hwep);
1319                 retval |= hw_ep_disable(hwep->ci, hwep->num, hwep->dir);
1320
1321                 if (hwep->type == USB_ENDPOINT_XFER_CONTROL)
1322                         hwep->dir = (hwep->dir == TX) ? RX : TX;
1323
1324         } while (hwep->dir != direction);
1325
1326         hwep->ep.desc = NULL;
1327
1328         spin_unlock_irqrestore(hwep->lock, flags);
1329         return retval;
1330 }
1331
1332 /**
1333  * ep_alloc_request: allocate a request object to use with this endpoint
1334  *
1335  * Check usb_ep_alloc_request() at "usb_gadget.h" for details
1336  */
1337 static struct usb_request *ep_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1338 {
1339         struct ci_hw_req *hwreq = NULL;
1340
1341         if (ep == NULL)
1342                 return NULL;
1343
1344         hwreq = kzalloc(sizeof(struct ci_hw_req), gfp_flags);
1345         if (hwreq != NULL) {
1346                 INIT_LIST_HEAD(&hwreq->queue);
1347                 INIT_LIST_HEAD(&hwreq->tds);
1348         }
1349
1350         return (hwreq == NULL) ? NULL : &hwreq->req;
1351 }
1352
1353 /**
1354  * ep_free_request: frees a request object
1355  *
1356  * Check usb_ep_free_request() at "usb_gadget.h" for details
1357  */
1358 static void ep_free_request(struct usb_ep *ep, struct usb_request *req)
1359 {
1360         struct ci_hw_ep  *hwep  = container_of(ep,  struct ci_hw_ep, ep);
1361         struct ci_hw_req *hwreq = container_of(req, struct ci_hw_req, req);
1362         struct td_node *node, *tmpnode;
1363         unsigned long flags;
1364
1365         if (ep == NULL || req == NULL) {
1366                 return;
1367         } else if (!list_empty(&hwreq->queue)) {
1368                 dev_err(hwep->ci->dev, "freeing queued request\n");
1369                 return;
1370         }
1371
1372         spin_lock_irqsave(hwep->lock, flags);
1373
1374         list_for_each_entry_safe(node, tmpnode, &hwreq->tds, td) {
1375                 dma_pool_free(hwep->td_pool, node->ptr, node->dma);
1376                 list_del_init(&node->td);
1377                 node->ptr = NULL;
1378                 kfree(node);
1379         }
1380
1381         kfree(hwreq);
1382
1383         spin_unlock_irqrestore(hwep->lock, flags);
1384 }
1385
1386 /**
1387  * ep_queue: queues (submits) an I/O request to an endpoint
1388  *
1389  * Check usb_ep_queue()* at usb_gadget.h" for details
1390  */
1391 static int ep_queue(struct usb_ep *ep, struct usb_request *req,
1392                     gfp_t __maybe_unused gfp_flags)
1393 {
1394         struct ci_hw_ep  *hwep  = container_of(ep,  struct ci_hw_ep, ep);
1395         int retval = 0;
1396         unsigned long flags;
1397
1398         if (ep == NULL || req == NULL || hwep->ep.desc == NULL)
1399                 return -EINVAL;
1400
1401         spin_lock_irqsave(hwep->lock, flags);
1402         retval = _ep_queue(ep, req, gfp_flags);
1403         spin_unlock_irqrestore(hwep->lock, flags);
1404         return retval;
1405 }
1406
1407 /**
1408  * ep_dequeue: dequeues (cancels, unlinks) an I/O request from an endpoint
1409  *
1410  * Check usb_ep_dequeue() at "usb_gadget.h" for details
1411  */
1412 static int ep_dequeue(struct usb_ep *ep, struct usb_request *req)
1413 {
1414         struct ci_hw_ep  *hwep  = container_of(ep,  struct ci_hw_ep, ep);
1415         struct ci_hw_req *hwreq = container_of(req, struct ci_hw_req, req);
1416         unsigned long flags;
1417         struct td_node *node, *tmpnode;
1418
1419         if (ep == NULL || req == NULL || hwreq->req.status != -EALREADY ||
1420                 hwep->ep.desc == NULL || list_empty(&hwreq->queue) ||
1421                 list_empty(&hwep->qh.queue))
1422                 return -EINVAL;
1423
1424         spin_lock_irqsave(hwep->lock, flags);
1425
1426         hw_ep_flush(hwep->ci, hwep->num, hwep->dir);
1427
1428         list_for_each_entry_safe(node, tmpnode, &hwreq->tds, td) {
1429                 dma_pool_free(hwep->td_pool, node->ptr, node->dma);
1430                 list_del(&node->td);
1431                 kfree(node);
1432         }
1433
1434         /* pop request */
1435         list_del_init(&hwreq->queue);
1436
1437         usb_gadget_unmap_request(&hwep->ci->gadget, req, hwep->dir);
1438
1439         req->status = -ECONNRESET;
1440
1441         if (hwreq->req.complete != NULL) {
1442                 spin_unlock(hwep->lock);
1443                 usb_gadget_giveback_request(&hwep->ep, &hwreq->req);
1444                 spin_lock(hwep->lock);
1445         }
1446
1447         spin_unlock_irqrestore(hwep->lock, flags);
1448         return 0;
1449 }
1450
1451 /**
1452  * ep_set_halt: sets the endpoint halt feature
1453  *
1454  * Check usb_ep_set_halt() at "usb_gadget.h" for details
1455  */
1456 static int ep_set_halt(struct usb_ep *ep, int value)
1457 {
1458         return _ep_set_halt(ep, value, true);
1459 }
1460
1461 /**
1462  * ep_set_wedge: sets the halt feature and ignores clear requests
1463  *
1464  * Check usb_ep_set_wedge() at "usb_gadget.h" for details
1465  */
1466 static int ep_set_wedge(struct usb_ep *ep)
1467 {
1468         struct ci_hw_ep *hwep = container_of(ep, struct ci_hw_ep, ep);
1469         unsigned long flags;
1470
1471         if (ep == NULL || hwep->ep.desc == NULL)
1472                 return -EINVAL;
1473
1474         spin_lock_irqsave(hwep->lock, flags);
1475         hwep->wedge = 1;
1476         spin_unlock_irqrestore(hwep->lock, flags);
1477
1478         return usb_ep_set_halt(ep);
1479 }
1480
1481 /**
1482  * ep_fifo_flush: flushes contents of a fifo
1483  *
1484  * Check usb_ep_fifo_flush() at "usb_gadget.h" for details
1485  */
1486 static void ep_fifo_flush(struct usb_ep *ep)
1487 {
1488         struct ci_hw_ep *hwep = container_of(ep, struct ci_hw_ep, ep);
1489         unsigned long flags;
1490
1491         if (ep == NULL) {
1492                 dev_err(hwep->ci->dev, "%02X: -EINVAL\n", _usb_addr(hwep));
1493                 return;
1494         }
1495
1496         spin_lock_irqsave(hwep->lock, flags);
1497
1498         hw_ep_flush(hwep->ci, hwep->num, hwep->dir);
1499
1500         spin_unlock_irqrestore(hwep->lock, flags);
1501 }
1502
1503 /**
1504  * Endpoint-specific part of the API to the USB controller hardware
1505  * Check "usb_gadget.h" for details
1506  */
1507 static const struct usb_ep_ops usb_ep_ops = {
1508         .enable        = ep_enable,
1509         .disable       = ep_disable,
1510         .alloc_request = ep_alloc_request,
1511         .free_request  = ep_free_request,
1512         .queue         = ep_queue,
1513         .dequeue       = ep_dequeue,
1514         .set_halt      = ep_set_halt,
1515         .set_wedge     = ep_set_wedge,
1516         .fifo_flush    = ep_fifo_flush,
1517 };
1518
1519 /******************************************************************************
1520  * GADGET block
1521  *****************************************************************************/
1522 static int ci_udc_vbus_session(struct usb_gadget *_gadget, int is_active)
1523 {
1524         struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
1525         unsigned long flags;
1526         int gadget_ready = 0;
1527
1528         spin_lock_irqsave(&ci->lock, flags);
1529         ci->vbus_active = is_active;
1530         if (ci->driver)
1531                 gadget_ready = 1;
1532         spin_unlock_irqrestore(&ci->lock, flags);
1533
1534         if (gadget_ready) {
1535                 if (is_active) {
1536                         pm_runtime_get_sync(&_gadget->dev);
1537                         hw_device_reset(ci);
1538                         hw_device_state(ci, ci->ep0out->qh.dma);
1539                         usb_gadget_set_state(_gadget, USB_STATE_POWERED);
1540                         usb_udc_vbus_handler(_gadget, true);
1541                 } else {
1542                         usb_udc_vbus_handler(_gadget, false);
1543                         if (ci->driver)
1544                                 ci->driver->disconnect(&ci->gadget);
1545                         hw_device_state(ci, 0);
1546                         if (ci->platdata->notify_event)
1547                                 ci->platdata->notify_event(ci,
1548                                 CI_HDRC_CONTROLLER_STOPPED_EVENT);
1549                         _gadget_stop_activity(&ci->gadget);
1550                         pm_runtime_put_sync(&_gadget->dev);
1551                         usb_gadget_set_state(_gadget, USB_STATE_NOTATTACHED);
1552                 }
1553         }
1554
1555         return 0;
1556 }
1557
1558 static int ci_udc_wakeup(struct usb_gadget *_gadget)
1559 {
1560         struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
1561         unsigned long flags;
1562         int ret = 0;
1563
1564         spin_lock_irqsave(&ci->lock, flags);
1565         if (!ci->remote_wakeup) {
1566                 ret = -EOPNOTSUPP;
1567                 goto out;
1568         }
1569         if (!hw_read(ci, OP_PORTSC, PORTSC_SUSP)) {
1570                 ret = -EINVAL;
1571                 goto out;
1572         }
1573         hw_write(ci, OP_PORTSC, PORTSC_FPR, PORTSC_FPR);
1574 out:
1575         spin_unlock_irqrestore(&ci->lock, flags);
1576         return ret;
1577 }
1578
1579 static int ci_udc_vbus_draw(struct usb_gadget *_gadget, unsigned ma)
1580 {
1581         struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
1582
1583         if (ci->usb_phy)
1584                 return usb_phy_set_power(ci->usb_phy, ma);
1585         return -ENOTSUPP;
1586 }
1587
1588 static int ci_udc_selfpowered(struct usb_gadget *_gadget, int is_on)
1589 {
1590         struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
1591         struct ci_hw_ep *hwep = ci->ep0in;
1592         unsigned long flags;
1593
1594         spin_lock_irqsave(hwep->lock, flags);
1595         _gadget->is_selfpowered = (is_on != 0);
1596         spin_unlock_irqrestore(hwep->lock, flags);
1597
1598         return 0;
1599 }
1600
1601 /* Change Data+ pullup status
1602  * this func is used by usb_gadget_connect/disconnet
1603  */
1604 static int ci_udc_pullup(struct usb_gadget *_gadget, int is_on)
1605 {
1606         struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget);
1607
1608         /*
1609          * Data+ pullup controlled by OTG state machine in OTG fsm mode;
1610          * and don't touch Data+ in host mode for dual role config.
1611          */
1612         if (ci_otg_is_fsm_mode(ci) || ci->role == CI_ROLE_HOST)
1613                 return 0;
1614
1615         pm_runtime_get_sync(&ci->gadget.dev);
1616         if (is_on)
1617                 hw_write(ci, OP_USBCMD, USBCMD_RS, USBCMD_RS);
1618         else
1619                 hw_write(ci, OP_USBCMD, USBCMD_RS, 0);
1620         pm_runtime_put_sync(&ci->gadget.dev);
1621
1622         return 0;
1623 }
1624
1625 static int ci_udc_start(struct usb_gadget *gadget,
1626                          struct usb_gadget_driver *driver);
1627 static int ci_udc_stop(struct usb_gadget *gadget);
1628 /**
1629  * Device operations part of the API to the USB controller hardware,
1630  * which don't involve endpoints (or i/o)
1631  * Check  "usb_gadget.h" for details
1632  */
1633 static const struct usb_gadget_ops usb_gadget_ops = {
1634         .vbus_session   = ci_udc_vbus_session,
1635         .wakeup         = ci_udc_wakeup,
1636         .set_selfpowered        = ci_udc_selfpowered,
1637         .pullup         = ci_udc_pullup,
1638         .vbus_draw      = ci_udc_vbus_draw,
1639         .udc_start      = ci_udc_start,
1640         .udc_stop       = ci_udc_stop,
1641 };
1642
1643 static int init_eps(struct ci_hdrc *ci)
1644 {
1645         int retval = 0, i, j;
1646
1647         for (i = 0; i < ci->hw_ep_max/2; i++)
1648                 for (j = RX; j <= TX; j++) {
1649                         int k = i + j * ci->hw_ep_max/2;
1650                         struct ci_hw_ep *hwep = &ci->ci_hw_ep[k];
1651
1652                         scnprintf(hwep->name, sizeof(hwep->name), "ep%i%s", i,
1653                                         (j == TX)  ? "in" : "out");
1654
1655                         hwep->ci          = ci;
1656                         hwep->lock         = &ci->lock;
1657                         hwep->td_pool      = ci->td_pool;
1658
1659                         hwep->ep.name      = hwep->name;
1660                         hwep->ep.ops       = &usb_ep_ops;
1661
1662                         if (i == 0) {
1663                                 hwep->ep.caps.type_control = true;
1664                         } else {
1665                                 hwep->ep.caps.type_iso = true;
1666                                 hwep->ep.caps.type_bulk = true;
1667                                 hwep->ep.caps.type_int = true;
1668                         }
1669
1670                         if (j == TX)
1671                                 hwep->ep.caps.dir_in = true;
1672                         else
1673                                 hwep->ep.caps.dir_out = true;
1674
1675                         /*
1676                          * for ep0: maxP defined in desc, for other
1677                          * eps, maxP is set by epautoconfig() called
1678                          * by gadget layer
1679                          */
1680                         usb_ep_set_maxpacket_limit(&hwep->ep, (unsigned short)~0);
1681
1682                         INIT_LIST_HEAD(&hwep->qh.queue);
1683                         hwep->qh.ptr = dma_pool_alloc(ci->qh_pool, GFP_KERNEL,
1684                                                      &hwep->qh.dma);
1685                         if (hwep->qh.ptr == NULL)
1686                                 retval = -ENOMEM;
1687                         else
1688                                 memset(hwep->qh.ptr, 0, sizeof(*hwep->qh.ptr));
1689
1690                         /*
1691                          * set up shorthands for ep0 out and in endpoints,
1692                          * don't add to gadget's ep_list
1693                          */
1694                         if (i == 0) {
1695                                 if (j == RX)
1696                                         ci->ep0out = hwep;
1697                                 else
1698                                         ci->ep0in = hwep;
1699
1700                                 usb_ep_set_maxpacket_limit(&hwep->ep, CTRL_PAYLOAD_MAX);
1701                                 continue;
1702                         }
1703
1704                         list_add_tail(&hwep->ep.ep_list, &ci->gadget.ep_list);
1705                 }
1706
1707         return retval;
1708 }
1709
1710 static void destroy_eps(struct ci_hdrc *ci)
1711 {
1712         int i;
1713
1714         for (i = 0; i < ci->hw_ep_max; i++) {
1715                 struct ci_hw_ep *hwep = &ci->ci_hw_ep[i];
1716
1717                 if (hwep->pending_td)
1718                         free_pending_td(hwep);
1719                 dma_pool_free(ci->qh_pool, hwep->qh.ptr, hwep->qh.dma);
1720         }
1721 }
1722
1723 /**
1724  * ci_udc_start: register a gadget driver
1725  * @gadget: our gadget
1726  * @driver: the driver being registered
1727  *
1728  * Interrupts are enabled here.
1729  */
1730 static int ci_udc_start(struct usb_gadget *gadget,
1731                          struct usb_gadget_driver *driver)
1732 {
1733         struct ci_hdrc *ci = container_of(gadget, struct ci_hdrc, gadget);
1734         unsigned long flags;
1735         int retval = -ENOMEM;
1736
1737         if (driver->disconnect == NULL)
1738                 return -EINVAL;
1739
1740
1741         ci->ep0out->ep.desc = &ctrl_endpt_out_desc;
1742         retval = usb_ep_enable(&ci->ep0out->ep);
1743         if (retval)
1744                 return retval;
1745
1746         ci->ep0in->ep.desc = &ctrl_endpt_in_desc;
1747         retval = usb_ep_enable(&ci->ep0in->ep);
1748         if (retval)
1749                 return retval;
1750
1751         ci->driver = driver;
1752
1753         /* Start otg fsm for B-device */
1754         if (ci_otg_is_fsm_mode(ci) && ci->fsm.id) {
1755                 ci_hdrc_otg_fsm_start(ci);
1756                 return retval;
1757         }
1758
1759         pm_runtime_get_sync(&ci->gadget.dev);
1760         if (ci->vbus_active) {
1761                 spin_lock_irqsave(&ci->lock, flags);
1762                 hw_device_reset(ci);
1763         } else {
1764                 usb_udc_vbus_handler(&ci->gadget, false);
1765                 pm_runtime_put_sync(&ci->gadget.dev);
1766                 return retval;
1767         }
1768
1769         retval = hw_device_state(ci, ci->ep0out->qh.dma);
1770         spin_unlock_irqrestore(&ci->lock, flags);
1771         if (retval)
1772                 pm_runtime_put_sync(&ci->gadget.dev);
1773
1774         return retval;
1775 }
1776
1777 static void ci_udc_stop_for_otg_fsm(struct ci_hdrc *ci)
1778 {
1779         if (!ci_otg_is_fsm_mode(ci))
1780                 return;
1781
1782         mutex_lock(&ci->fsm.lock);
1783         if (ci->fsm.otg->state == OTG_STATE_A_PERIPHERAL) {
1784                 ci->fsm.a_bidl_adis_tmout = 1;
1785                 ci_hdrc_otg_fsm_start(ci);
1786         } else if (ci->fsm.otg->state == OTG_STATE_B_PERIPHERAL) {
1787                 ci->fsm.protocol = PROTO_UNDEF;
1788                 ci->fsm.otg->state = OTG_STATE_UNDEFINED;
1789         }
1790         mutex_unlock(&ci->fsm.lock);
1791 }
1792
1793 /**
1794  * ci_udc_stop: unregister a gadget driver
1795  */
1796 static int ci_udc_stop(struct usb_gadget *gadget)
1797 {
1798         struct ci_hdrc *ci = container_of(gadget, struct ci_hdrc, gadget);
1799         unsigned long flags;
1800
1801         spin_lock_irqsave(&ci->lock, flags);
1802
1803         if (ci->vbus_active) {
1804                 hw_device_state(ci, 0);
1805                 if (ci->platdata->notify_event)
1806                         ci->platdata->notify_event(ci,
1807                         CI_HDRC_CONTROLLER_STOPPED_EVENT);
1808                 spin_unlock_irqrestore(&ci->lock, flags);
1809                 _gadget_stop_activity(&ci->gadget);
1810                 spin_lock_irqsave(&ci->lock, flags);
1811                 pm_runtime_put(&ci->gadget.dev);
1812         }
1813
1814         ci->driver = NULL;
1815         spin_unlock_irqrestore(&ci->lock, flags);
1816
1817         ci_udc_stop_for_otg_fsm(ci);
1818         return 0;
1819 }
1820
1821 /******************************************************************************
1822  * BUS block
1823  *****************************************************************************/
1824 /**
1825  * udc_irq: ci interrupt handler
1826  *
1827  * This function returns IRQ_HANDLED if the IRQ has been handled
1828  * It locks access to registers
1829  */
1830 static irqreturn_t udc_irq(struct ci_hdrc *ci)
1831 {
1832         irqreturn_t retval;
1833         u32 intr;
1834
1835         if (ci == NULL)
1836                 return IRQ_HANDLED;
1837
1838         spin_lock(&ci->lock);
1839
1840         if (ci->platdata->flags & CI_HDRC_REGS_SHARED) {
1841                 if (hw_read(ci, OP_USBMODE, USBMODE_CM) !=
1842                                 USBMODE_CM_DC) {
1843                         spin_unlock(&ci->lock);
1844                         return IRQ_NONE;
1845                 }
1846         }
1847         intr = hw_test_and_clear_intr_active(ci);
1848
1849         if (intr) {
1850                 /* order defines priority - do NOT change it */
1851                 if (USBi_URI & intr)
1852                         isr_reset_handler(ci);
1853
1854                 if (USBi_PCI & intr) {
1855                         ci->gadget.speed = hw_port_is_high_speed(ci) ?
1856                                 USB_SPEED_HIGH : USB_SPEED_FULL;
1857                         if (ci->suspended && ci->driver->resume) {
1858                                 spin_unlock(&ci->lock);
1859                                 ci->driver->resume(&ci->gadget);
1860                                 spin_lock(&ci->lock);
1861                                 ci->suspended = 0;
1862                         }
1863                 }
1864
1865                 if (USBi_UI  & intr)
1866                         isr_tr_complete_handler(ci);
1867
1868                 if (USBi_SLI & intr) {
1869                         if (ci->gadget.speed != USB_SPEED_UNKNOWN &&
1870                             ci->driver->suspend) {
1871                                 ci->suspended = 1;
1872                                 spin_unlock(&ci->lock);
1873                                 ci->driver->suspend(&ci->gadget);
1874                                 usb_gadget_set_state(&ci->gadget,
1875                                                 USB_STATE_SUSPENDED);
1876                                 spin_lock(&ci->lock);
1877                         }
1878                 }
1879                 retval = IRQ_HANDLED;
1880         } else {
1881                 retval = IRQ_NONE;
1882         }
1883         spin_unlock(&ci->lock);
1884
1885         return retval;
1886 }
1887
1888 /**
1889  * udc_start: initialize gadget role
1890  * @ci: chipidea controller
1891  */
1892 static int udc_start(struct ci_hdrc *ci)
1893 {
1894         struct device *dev = ci->dev;
1895         struct usb_otg_caps *otg_caps = &ci->platdata->ci_otg_caps;
1896         int retval = 0;
1897
1898         spin_lock_init(&ci->lock);
1899
1900         ci->gadget.ops          = &usb_gadget_ops;
1901         ci->gadget.speed        = USB_SPEED_UNKNOWN;
1902         ci->gadget.max_speed    = USB_SPEED_HIGH;
1903         ci->gadget.name         = ci->platdata->name;
1904         ci->gadget.otg_caps     = otg_caps;
1905
1906         if (ci->is_otg && (otg_caps->hnp_support || otg_caps->srp_support ||
1907                                                 otg_caps->adp_support))
1908                 ci->gadget.is_otg = 1;
1909
1910         INIT_LIST_HEAD(&ci->gadget.ep_list);
1911
1912         /* alloc resources */
1913         ci->qh_pool = dma_pool_create("ci_hw_qh", dev,
1914                                        sizeof(struct ci_hw_qh),
1915                                        64, CI_HDRC_PAGE_SIZE);
1916         if (ci->qh_pool == NULL)
1917                 return -ENOMEM;
1918
1919         ci->td_pool = dma_pool_create("ci_hw_td", dev,
1920                                        sizeof(struct ci_hw_td),
1921                                        64, CI_HDRC_PAGE_SIZE);
1922         if (ci->td_pool == NULL) {
1923                 retval = -ENOMEM;
1924                 goto free_qh_pool;
1925         }
1926
1927         retval = init_eps(ci);
1928         if (retval)
1929                 goto free_pools;
1930
1931         ci->gadget.ep0 = &ci->ep0in->ep;
1932
1933         retval = usb_add_gadget_udc(dev, &ci->gadget);
1934         if (retval)
1935                 goto destroy_eps;
1936
1937         pm_runtime_no_callbacks(&ci->gadget.dev);
1938         pm_runtime_enable(&ci->gadget.dev);
1939
1940         return retval;
1941
1942 destroy_eps:
1943         destroy_eps(ci);
1944 free_pools:
1945         dma_pool_destroy(ci->td_pool);
1946 free_qh_pool:
1947         dma_pool_destroy(ci->qh_pool);
1948         return retval;
1949 }
1950
1951 /**
1952  * ci_hdrc_gadget_destroy: parent remove must call this to remove UDC
1953  *
1954  * No interrupts active, the IRQ has been released
1955  */
1956 void ci_hdrc_gadget_destroy(struct ci_hdrc *ci)
1957 {
1958         if (!ci->roles[CI_ROLE_GADGET])
1959                 return;
1960
1961         usb_del_gadget_udc(&ci->gadget);
1962
1963         destroy_eps(ci);
1964
1965         dma_pool_destroy(ci->td_pool);
1966         dma_pool_destroy(ci->qh_pool);
1967 }
1968
1969 static int udc_id_switch_for_device(struct ci_hdrc *ci)
1970 {
1971         if (ci->is_otg)
1972                 /* Clear and enable BSV irq */
1973                 hw_write_otgsc(ci, OTGSC_BSVIS | OTGSC_BSVIE,
1974                                         OTGSC_BSVIS | OTGSC_BSVIE);
1975
1976         return 0;
1977 }
1978
1979 static void udc_id_switch_for_host(struct ci_hdrc *ci)
1980 {
1981         /*
1982          * host doesn't care B_SESSION_VALID event
1983          * so clear and disbale BSV irq
1984          */
1985         if (ci->is_otg)
1986                 hw_write_otgsc(ci, OTGSC_BSVIE | OTGSC_BSVIS, OTGSC_BSVIS);
1987 }
1988
1989 /**
1990  * ci_hdrc_gadget_init - initialize device related bits
1991  * ci: the controller
1992  *
1993  * This function initializes the gadget, if the device is "device capable".
1994  */
1995 int ci_hdrc_gadget_init(struct ci_hdrc *ci)
1996 {
1997         struct ci_role_driver *rdrv;
1998
1999         if (!hw_read(ci, CAP_DCCPARAMS, DCCPARAMS_DC))
2000                 return -ENXIO;
2001
2002         rdrv = devm_kzalloc(ci->dev, sizeof(struct ci_role_driver), GFP_KERNEL);
2003         if (!rdrv)
2004                 return -ENOMEM;
2005
2006         rdrv->start     = udc_id_switch_for_device;
2007         rdrv->stop      = udc_id_switch_for_host;
2008         rdrv->irq       = udc_irq;
2009         rdrv->name      = "gadget";
2010         ci->roles[CI_ROLE_GADGET] = rdrv;
2011
2012         return udc_start(ci);
2013 }