Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6] / drivers / usb / host / ohci-hub.c
1 /*
2  * OHCI HCD (Host Controller Driver) for USB.
3  *
4  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
5  * (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
6  *
7  * This file is licenced under GPL
8  */
9
10 /*-------------------------------------------------------------------------*/
11
12 /*
13  * OHCI Root Hub ... the nonsharable stuff
14  */
15
16 #define dbg_port(hc,label,num,value) \
17         ohci_dbg (hc, \
18                 "%s roothub.portstatus [%d] " \
19                 "= 0x%08x%s%s%s%s%s%s%s%s%s%s%s%s\n", \
20                 label, num, temp, \
21                 (temp & RH_PS_PRSC) ? " PRSC" : "", \
22                 (temp & RH_PS_OCIC) ? " OCIC" : "", \
23                 (temp & RH_PS_PSSC) ? " PSSC" : "", \
24                 (temp & RH_PS_PESC) ? " PESC" : "", \
25                 (temp & RH_PS_CSC) ? " CSC" : "", \
26                 \
27                 (temp & RH_PS_LSDA) ? " LSDA" : "", \
28                 (temp & RH_PS_PPS) ? " PPS" : "", \
29                 (temp & RH_PS_PRS) ? " PRS" : "", \
30                 (temp & RH_PS_POCI) ? " POCI" : "", \
31                 (temp & RH_PS_PSS) ? " PSS" : "", \
32                 \
33                 (temp & RH_PS_PES) ? " PES" : "", \
34                 (temp & RH_PS_CCS) ? " CCS" : "" \
35                 );
36
37 /*-------------------------------------------------------------------------*/
38
39 #define OHCI_SCHED_ENABLES \
40         (OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
41
42 static void dl_done_list (struct ohci_hcd *);
43 static void finish_unlinks (struct ohci_hcd *, u16);
44
45 #ifdef  CONFIG_PM
46 static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop)
47 __releases(ohci->lock)
48 __acquires(ohci->lock)
49 {
50         int                     status = 0;
51
52         ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
53         switch (ohci->hc_control & OHCI_CTRL_HCFS) {
54         case OHCI_USB_RESUME:
55                 ohci_dbg (ohci, "resume/suspend?\n");
56                 ohci->hc_control &= ~OHCI_CTRL_HCFS;
57                 ohci->hc_control |= OHCI_USB_RESET;
58                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
59                 (void) ohci_readl (ohci, &ohci->regs->control);
60                 /* FALL THROUGH */
61         case OHCI_USB_RESET:
62                 status = -EBUSY;
63                 ohci_dbg (ohci, "needs reinit!\n");
64                 goto done;
65         case OHCI_USB_SUSPEND:
66                 if (!ohci->autostop) {
67                         ohci_dbg (ohci, "already suspended\n");
68                         goto done;
69                 }
70         }
71         ohci_dbg (ohci, "%s root hub\n",
72                         autostop ? "auto-stop" : "suspend");
73
74         /* First stop any processing */
75         if (!autostop && (ohci->hc_control & OHCI_SCHED_ENABLES)) {
76                 ohci->hc_control &= ~OHCI_SCHED_ENABLES;
77                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
78                 ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
79                 ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
80
81                 /* sched disables take effect on the next frame,
82                  * then the last WDH could take 6+ msec
83                  */
84                 ohci_dbg (ohci, "stopping schedules ...\n");
85                 ohci->autostop = 0;
86                 spin_unlock_irq (&ohci->lock);
87                 msleep (8);
88                 spin_lock_irq (&ohci->lock);
89         }
90         dl_done_list (ohci);
91         finish_unlinks (ohci, ohci_frame_no(ohci));
92
93         /* maybe resume can wake root hub */
94         if (ohci_to_hcd(ohci)->self.root_hub->do_remote_wakeup || autostop) {
95                 ohci->hc_control |= OHCI_CTRL_RWE;
96         } else {
97                 ohci_writel(ohci, OHCI_INTR_RHSC | OHCI_INTR_RD,
98                                 &ohci->regs->intrdisable);
99                 ohci->hc_control &= ~OHCI_CTRL_RWE;
100         }
101
102         /* Suspend hub ... this is the "global (to this bus) suspend" mode,
103          * which doesn't imply ports will first be individually suspended.
104          */
105         ohci->hc_control &= ~OHCI_CTRL_HCFS;
106         ohci->hc_control |= OHCI_USB_SUSPEND;
107         ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
108         (void) ohci_readl (ohci, &ohci->regs->control);
109
110         /* no resumes until devices finish suspending */
111         if (!autostop) {
112                 ohci->next_statechange = jiffies + msecs_to_jiffies (5);
113                 ohci->autostop = 0;
114         }
115
116 done:
117         return status;
118 }
119
120 static inline struct ed *find_head (struct ed *ed)
121 {
122         /* for bulk and control lists */
123         while (ed->ed_prev)
124                 ed = ed->ed_prev;
125         return ed;
126 }
127
128 /* caller has locked the root hub */
129 static int ohci_rh_resume (struct ohci_hcd *ohci)
130 __releases(ohci->lock)
131 __acquires(ohci->lock)
132 {
133         struct usb_hcd          *hcd = ohci_to_hcd (ohci);
134         u32                     temp, enables;
135         int                     status = -EINPROGRESS;
136         int                     autostopped = ohci->autostop;
137
138         ohci->autostop = 0;
139         ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
140
141         if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
142                 /* this can happen after resuming a swsusp snapshot */
143                 if (hcd->state == HC_STATE_RESUMING) {
144                         ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
145                                         ohci->hc_control);
146                         status = -EBUSY;
147                 /* this happens when pmcore resumes HC then root */
148                 } else {
149                         ohci_dbg (ohci, "duplicate resume\n");
150                         status = 0;
151                 }
152         } else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
153         case OHCI_USB_SUSPEND:
154                 ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
155                 ohci->hc_control |= OHCI_USB_RESUME;
156                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
157                 (void) ohci_readl (ohci, &ohci->regs->control);
158                 ohci_dbg (ohci, "%s root hub\n",
159                                 autostopped ? "auto-start" : "resume");
160                 break;
161         case OHCI_USB_RESUME:
162                 /* HCFS changes sometime after INTR_RD */
163                 ohci_dbg(ohci, "%swakeup root hub\n",
164                                 autostopped ? "auto-" : "");
165                 break;
166         case OHCI_USB_OPER:
167                 /* this can happen after resuming a swsusp snapshot */
168                 ohci_dbg (ohci, "snapshot resume? reinit\n");
169                 status = -EBUSY;
170                 break;
171         default:                /* RESET, we lost power */
172                 ohci_dbg (ohci, "lost power\n");
173                 status = -EBUSY;
174         }
175         if (status == -EBUSY) {
176                 if (!autostopped) {
177                         spin_unlock_irq (&ohci->lock);
178                         (void) ohci_init (ohci);
179                         status = ohci_restart (ohci);
180
181                         usb_root_hub_lost_power(hcd->self.root_hub);
182
183                         spin_lock_irq (&ohci->lock);
184                 }
185                 return status;
186         }
187         if (status != -EINPROGRESS)
188                 return status;
189         if (autostopped)
190                 goto skip_resume;
191         spin_unlock_irq (&ohci->lock);
192
193         /* Some controllers (lucent erratum) need extra-long delays */
194         msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);
195
196         temp = ohci_readl (ohci, &ohci->regs->control);
197         temp &= OHCI_CTRL_HCFS;
198         if (temp != OHCI_USB_RESUME) {
199                 ohci_err (ohci, "controller won't resume\n");
200                 spin_lock_irq(&ohci->lock);
201                 return -EBUSY;
202         }
203
204         /* disable old schedule state, reinit from scratch */
205         ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
206         ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
207         ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
208         ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
209         ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
210         ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
211
212         /* Sometimes PCI D3 suspend trashes frame timings ... */
213         periodic_reinit (ohci);
214
215         /* the following code is executed with ohci->lock held and
216          * irqs disabled if and only if autostopped is true
217          */
218
219 skip_resume:
220         /* interrupts might have been disabled */
221         ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
222         if (ohci->ed_rm_list)
223                 ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
224
225         /* Then re-enable operations */
226         ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
227         (void) ohci_readl (ohci, &ohci->regs->control);
228         if (!autostopped)
229                 msleep (3);
230
231         temp = ohci->hc_control;
232         temp &= OHCI_CTRL_RWC;
233         temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
234         ohci->hc_control = temp;
235         ohci_writel (ohci, temp, &ohci->regs->control);
236         (void) ohci_readl (ohci, &ohci->regs->control);
237
238         /* TRSMRCY */
239         if (!autostopped) {
240                 msleep (10);
241                 spin_lock_irq (&ohci->lock);
242         }
243         /* now ohci->lock is always held and irqs are always disabled */
244
245         /* keep it alive for more than ~5x suspend + resume costs */
246         ohci->next_statechange = jiffies + STATECHANGE_DELAY;
247
248         /* maybe turn schedules back on */
249         enables = 0;
250         temp = 0;
251         if (!ohci->ed_rm_list) {
252                 if (ohci->ed_controltail) {
253                         ohci_writel (ohci,
254                                         find_head (ohci->ed_controltail)->dma,
255                                         &ohci->regs->ed_controlhead);
256                         enables |= OHCI_CTRL_CLE;
257                         temp |= OHCI_CLF;
258                 }
259                 if (ohci->ed_bulktail) {
260                         ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
261                                 &ohci->regs->ed_bulkhead);
262                         enables |= OHCI_CTRL_BLE;
263                         temp |= OHCI_BLF;
264                 }
265         }
266         if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
267                 enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
268         if (enables) {
269                 ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
270                 ohci->hc_control |= enables;
271                 ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
272                 if (temp)
273                         ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
274                 (void) ohci_readl (ohci, &ohci->regs->control);
275         }
276
277         return 0;
278 }
279
280 static int ohci_bus_suspend (struct usb_hcd *hcd)
281 {
282         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
283         int                     rc;
284
285         spin_lock_irq (&ohci->lock);
286
287         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
288                 rc = -ESHUTDOWN;
289         else
290                 rc = ohci_rh_suspend (ohci, 0);
291         spin_unlock_irq (&ohci->lock);
292         return rc;
293 }
294
295 static int ohci_bus_resume (struct usb_hcd *hcd)
296 {
297         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
298         int                     rc;
299
300         if (time_before (jiffies, ohci->next_statechange))
301                 msleep(5);
302
303         spin_lock_irq (&ohci->lock);
304
305         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
306                 rc = -ESHUTDOWN;
307         else
308                 rc = ohci_rh_resume (ohci);
309         spin_unlock_irq (&ohci->lock);
310
311         /* poll until we know a device is connected or we autostop */
312         if (rc == 0)
313                 usb_hcd_poll_rh_status(hcd);
314         return rc;
315 }
316
317 /* Carry out the final steps of resuming the controller device */
318 static void ohci_finish_controller_resume(struct usb_hcd *hcd)
319 {
320         struct ohci_hcd         *ohci = hcd_to_ohci(hcd);
321         int                     port;
322         bool                    need_reinit = false;
323
324         /* See if the controller is already running or has been reset */
325         ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
326         if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
327                 need_reinit = true;
328         } else {
329                 switch (ohci->hc_control & OHCI_CTRL_HCFS) {
330                 case OHCI_USB_OPER:
331                 case OHCI_USB_RESET:
332                         need_reinit = true;
333                 }
334         }
335
336         /* If needed, reinitialize and suspend the root hub */
337         if (need_reinit) {
338                 spin_lock_irq(&ohci->lock);
339                 hcd->state = HC_STATE_RESUMING;
340                 ohci_rh_resume(ohci);
341                 hcd->state = HC_STATE_QUIESCING;
342                 ohci_rh_suspend(ohci, 0);
343                 hcd->state = HC_STATE_SUSPENDED;
344                 spin_unlock_irq(&ohci->lock);
345         }
346
347         /* Normally just turn on port power and enable interrupts */
348         else {
349                 ohci_dbg(ohci, "powerup ports\n");
350                 for (port = 0; port < ohci->num_ports; port++)
351                         ohci_writel(ohci, RH_PS_PPS,
352                                         &ohci->regs->roothub.portstatus[port]);
353
354                 ohci_writel(ohci, OHCI_INTR_MIE, &ohci->regs->intrenable);
355                 ohci_readl(ohci, &ohci->regs->intrenable);
356                 msleep(20);
357         }
358 }
359
360 /* Carry out polling-, autostop-, and autoresume-related state changes */
361 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
362                 int any_connected)
363 {
364         int     poll_rh = 1;
365         int     rhsc;
366
367         rhsc = ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC;
368         switch (ohci->hc_control & OHCI_CTRL_HCFS) {
369
370         case OHCI_USB_OPER:
371                 /* If no status changes are pending, enable status-change
372                  * interrupts.
373                  */
374                 if (!rhsc && !changed) {
375                         rhsc = OHCI_INTR_RHSC;
376                         ohci_writel(ohci, rhsc, &ohci->regs->intrenable);
377                 }
378
379                 /* Keep on polling until we know a device is connected
380                  * and RHSC is enabled, or until we autostop.
381                  */
382                 if (!ohci->autostop) {
383                         if (any_connected ||
384                                         !device_may_wakeup(&ohci_to_hcd(ohci)
385                                                 ->self.root_hub->dev)) {
386                                 if (rhsc)
387                                         poll_rh = 0;
388                         } else {
389                                 ohci->autostop = 1;
390                                 ohci->next_statechange = jiffies + HZ;
391                         }
392
393                 /* if no devices have been attached for one second, autostop */
394                 } else {
395                         if (changed || any_connected) {
396                                 ohci->autostop = 0;
397                                 ohci->next_statechange = jiffies +
398                                                 STATECHANGE_DELAY;
399                         } else if (rhsc && time_after_eq(jiffies,
400                                                 ohci->next_statechange)
401                                         && !ohci->ed_rm_list
402                                         && !(ohci->hc_control &
403                                                 OHCI_SCHED_ENABLES)) {
404                                 ohci_rh_suspend(ohci, 1);
405                                 poll_rh = 0;
406                         }
407                 }
408                 break;
409
410         /* if there is a port change, autostart or ask to be resumed */
411         case OHCI_USB_SUSPEND:
412         case OHCI_USB_RESUME:
413                 if (changed) {
414                         if (ohci->autostop)
415                                 ohci_rh_resume(ohci);
416                         else
417                                 usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
418                 } else {
419                         if (!rhsc && (ohci->autostop ||
420                                         ohci_to_hcd(ohci)->self.root_hub->
421                                                 do_remote_wakeup))
422                                 ohci_writel(ohci, OHCI_INTR_RHSC,
423                                                 &ohci->regs->intrenable);
424
425                         /* everything is idle, no need for polling */
426                         poll_rh = 0;
427                 }
428                 break;
429         }
430         return poll_rh;
431 }
432
433 #else   /* CONFIG_PM */
434
435 static inline int ohci_rh_resume(struct ohci_hcd *ohci)
436 {
437         return 0;
438 }
439
440 /* Carry out polling-related state changes.
441  * autostop isn't used when CONFIG_PM is turned off.
442  */
443 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
444                 int any_connected)
445 {
446         /* If RHSC is enabled, don't poll */
447         if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
448                 return 0;
449
450         /* If no status changes are pending, enable status-change interrupts */
451         if (!changed) {
452                 ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
453                 return 0;
454         }
455         return 1;
456 }
457
458 #endif  /* CONFIG_PM */
459
460 /*-------------------------------------------------------------------------*/
461
462 /* build "status change" packet (one or two bytes) from HC registers */
463
464 static int
465 ohci_hub_status_data (struct usb_hcd *hcd, char *buf)
466 {
467         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
468         int             i, changed = 0, length = 1;
469         int             any_connected = 0;
470         unsigned long   flags;
471
472         spin_lock_irqsave (&ohci->lock, flags);
473         if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))
474                 goto done;
475
476         /* undocumented erratum seen on at least rev D */
477         if ((ohci->flags & OHCI_QUIRK_AMD756)
478                         && (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
479                 ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
480                           ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
481                 /* retry later; "should not happen" */
482                 goto done;
483         }
484
485         /* init status */
486         if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
487                 buf [0] = changed = 1;
488         else
489                 buf [0] = 0;
490         if (ohci->num_ports > 7) {
491                 buf [1] = 0;
492                 length++;
493         }
494
495         /* Some broken controllers never turn off RHCS in the interrupt
496          * status register.  For their sake we won't re-enable RHSC
497          * interrupts if the flag is already set.
498          */
499         if (ohci_readl(ohci, &ohci->regs->intrstatus) & OHCI_INTR_RHSC)
500                 changed = 1;
501
502         /* look at each port */
503         for (i = 0; i < ohci->num_ports; i++) {
504                 u32     status = roothub_portstatus (ohci, i);
505
506                 /* can't autostop if ports are connected */
507                 any_connected |= (status & RH_PS_CCS);
508
509                 if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
510                                 | RH_PS_OCIC | RH_PS_PRSC)) {
511                         changed = 1;
512                         if (i < 7)
513                             buf [0] |= 1 << (i + 1);
514                         else
515                             buf [1] |= 1 << (i - 7);
516                 }
517         }
518
519         hcd->poll_rh = ohci_root_hub_state_changes(ohci, changed,
520                         any_connected);
521
522 done:
523         spin_unlock_irqrestore (&ohci->lock, flags);
524
525         return changed ? length : 0;
526 }
527
528 /*-------------------------------------------------------------------------*/
529
530 static void
531 ohci_hub_descriptor (
532         struct ohci_hcd                 *ohci,
533         struct usb_hub_descriptor       *desc
534 ) {
535         u32             rh = roothub_a (ohci);
536         u16             temp;
537
538         desc->bDescriptorType = 0x29;
539         desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
540         desc->bHubContrCurrent = 0;
541
542         desc->bNbrPorts = ohci->num_ports;
543         temp = 1 + (ohci->num_ports / 8);
544         desc->bDescLength = 7 + 2 * temp;
545
546         temp = 0;
547         if (rh & RH_A_NPS)              /* no power switching? */
548             temp |= 0x0002;
549         if (rh & RH_A_PSM)              /* per-port power switching? */
550             temp |= 0x0001;
551         if (rh & RH_A_NOCP)             /* no overcurrent reporting? */
552             temp |= 0x0010;
553         else if (rh & RH_A_OCPM)        /* per-port overcurrent reporting? */
554             temp |= 0x0008;
555         desc->wHubCharacteristics = (__force __u16)cpu_to_hc16(ohci, temp);
556
557         /* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
558         rh = roothub_b (ohci);
559         memset(desc->bitmap, 0xff, sizeof(desc->bitmap));
560         desc->bitmap [0] = rh & RH_B_DR;
561         if (ohci->num_ports > 7) {
562                 desc->bitmap [1] = (rh & RH_B_DR) >> 8;
563                 desc->bitmap [2] = 0xff;
564         } else
565                 desc->bitmap [1] = 0xff;
566 }
567
568 /*-------------------------------------------------------------------------*/
569
570 #ifdef  CONFIG_USB_OTG
571
572 static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
573 {
574         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
575         u32                     status;
576
577         if (!port)
578                 return -EINVAL;
579         port--;
580
581         /* start port reset before HNP protocol times out */
582         status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
583         if (!(status & RH_PS_CCS))
584                 return -ENODEV;
585
586         /* khubd will finish the reset later */
587         ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
588         return 0;
589 }
590
591 #else
592
593 #define ohci_start_port_reset           NULL
594
595 #endif
596
597 /*-------------------------------------------------------------------------*/
598
599
600 /* See usb 7.1.7.5:  root hubs must issue at least 50 msec reset signaling,
601  * not necessarily continuous ... to guard against resume signaling.
602  * The short timeout is safe for non-root hubs, and is backward-compatible
603  * with earlier Linux hosts.
604  */
605 #ifdef  CONFIG_USB_SUSPEND
606 #define PORT_RESET_MSEC         50
607 #else
608 #define PORT_RESET_MSEC         10
609 #endif
610
611 /* this timer value might be vendor-specific ... */
612 #define PORT_RESET_HW_MSEC      10
613
614 /* wrap-aware logic morphed from <linux/jiffies.h> */
615 #define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
616
617 /* called from some task, normally khubd */
618 static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
619 {
620         __hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
621         u32     temp = 0;
622         u16     now = ohci_readl(ohci, &ohci->regs->fmnumber);
623         u16     reset_done = now + PORT_RESET_MSEC;
624         int     limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);
625
626         /* build a "continuous enough" reset signal, with up to
627          * 3msec gap between pulses.  scheduler HZ==100 must work;
628          * this might need to be deadline-scheduled.
629          */
630         do {
631                 int limit_2;
632
633                 /* spin until any current reset finishes */
634                 limit_2 = PORT_RESET_HW_MSEC * 2;
635                 while (--limit_2 >= 0) {
636                         temp = ohci_readl (ohci, portstat);
637                         /* handle e.g. CardBus eject */
638                         if (temp == ~(u32)0)
639                                 return -ESHUTDOWN;
640                         if (!(temp & RH_PS_PRS))
641                                 break;
642                         udelay (500);
643                 }
644
645                 /* timeout (a hardware error) has been observed when
646                  * EHCI sets CF while this driver is resetting a port;
647                  * presumably other disconnect paths might do it too.
648                  */
649                 if (limit_2 < 0) {
650                         ohci_dbg(ohci,
651                                 "port[%d] reset timeout, stat %08x\n",
652                                 port, temp);
653                         break;
654                 }
655
656                 if (!(temp & RH_PS_CCS))
657                         break;
658                 if (temp & RH_PS_PRSC)
659                         ohci_writel (ohci, RH_PS_PRSC, portstat);
660
661                 /* start the next reset, sleep till it's probably done */
662                 ohci_writel (ohci, RH_PS_PRS, portstat);
663                 msleep(PORT_RESET_HW_MSEC);
664                 now = ohci_readl(ohci, &ohci->regs->fmnumber);
665         } while (tick_before(now, reset_done) && --limit_1 >= 0);
666
667         /* caller synchronizes using PRSC ... and handles PRS
668          * still being set when this returns.
669          */
670
671         return 0;
672 }
673
674 static int ohci_hub_control (
675         struct usb_hcd  *hcd,
676         u16             typeReq,
677         u16             wValue,
678         u16             wIndex,
679         char            *buf,
680         u16             wLength
681 ) {
682         struct ohci_hcd *ohci = hcd_to_ohci (hcd);
683         int             ports = hcd_to_bus (hcd)->root_hub->maxchild;
684         u32             temp;
685         int             retval = 0;
686
687         if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
688                 return -ESHUTDOWN;
689
690         switch (typeReq) {
691         case ClearHubFeature:
692                 switch (wValue) {
693                 case C_HUB_OVER_CURRENT:
694                         ohci_writel (ohci, RH_HS_OCIC,
695                                         &ohci->regs->roothub.status);
696                 case C_HUB_LOCAL_POWER:
697                         break;
698                 default:
699                         goto error;
700                 }
701                 break;
702         case ClearPortFeature:
703                 if (!wIndex || wIndex > ports)
704                         goto error;
705                 wIndex--;
706
707                 switch (wValue) {
708                 case USB_PORT_FEAT_ENABLE:
709                         temp = RH_PS_CCS;
710                         break;
711                 case USB_PORT_FEAT_C_ENABLE:
712                         temp = RH_PS_PESC;
713                         break;
714                 case USB_PORT_FEAT_SUSPEND:
715                         temp = RH_PS_POCI;
716                         break;
717                 case USB_PORT_FEAT_C_SUSPEND:
718                         temp = RH_PS_PSSC;
719                         break;
720                 case USB_PORT_FEAT_POWER:
721                         temp = RH_PS_LSDA;
722                         break;
723                 case USB_PORT_FEAT_C_CONNECTION:
724                         temp = RH_PS_CSC;
725                         break;
726                 case USB_PORT_FEAT_C_OVER_CURRENT:
727                         temp = RH_PS_OCIC;
728                         break;
729                 case USB_PORT_FEAT_C_RESET:
730                         temp = RH_PS_PRSC;
731                         break;
732                 default:
733                         goto error;
734                 }
735                 ohci_writel (ohci, temp,
736                                 &ohci->regs->roothub.portstatus [wIndex]);
737                 // ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
738                 break;
739         case GetHubDescriptor:
740                 ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
741                 break;
742         case GetHubStatus:
743                 temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
744                 put_unaligned_le32(temp, buf);
745                 break;
746         case GetPortStatus:
747                 if (!wIndex || wIndex > ports)
748                         goto error;
749                 wIndex--;
750                 temp = roothub_portstatus (ohci, wIndex);
751                 put_unaligned_le32(temp, buf);
752
753 #ifndef OHCI_VERBOSE_DEBUG
754         if (*(u16*)(buf+2))     /* only if wPortChange is interesting */
755 #endif
756                 dbg_port (ohci, "GetStatus", wIndex, temp);
757                 break;
758         case SetHubFeature:
759                 switch (wValue) {
760                 case C_HUB_OVER_CURRENT:
761                         // FIXME:  this can be cleared, yes?
762                 case C_HUB_LOCAL_POWER:
763                         break;
764                 default:
765                         goto error;
766                 }
767                 break;
768         case SetPortFeature:
769                 if (!wIndex || wIndex > ports)
770                         goto error;
771                 wIndex--;
772                 switch (wValue) {
773                 case USB_PORT_FEAT_SUSPEND:
774 #ifdef  CONFIG_USB_OTG
775                         if (hcd->self.otg_port == (wIndex + 1)
776                                         && hcd->self.b_hnp_enable)
777                                 ohci->start_hnp(ohci);
778                         else
779 #endif
780                         ohci_writel (ohci, RH_PS_PSS,
781                                 &ohci->regs->roothub.portstatus [wIndex]);
782                         break;
783                 case USB_PORT_FEAT_POWER:
784                         ohci_writel (ohci, RH_PS_PPS,
785                                 &ohci->regs->roothub.portstatus [wIndex]);
786                         break;
787                 case USB_PORT_FEAT_RESET:
788                         retval = root_port_reset (ohci, wIndex);
789                         break;
790                 default:
791                         goto error;
792                 }
793                 break;
794
795         default:
796 error:
797                 /* "protocol stall" on error */
798                 retval = -EPIPE;
799         }
800         return retval;
801 }
802