xref: /openbmc/linux/drivers/usb/host/uhci-hub.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Universal Host Controller Interface driver for USB.
4  *
5  * Maintainer: Alan Stern <stern@rowland.harvard.edu>
6  *
7  * (C) Copyright 1999 Linus Torvalds
8  * (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
9  * (C) Copyright 1999 Randy Dunlap
10  * (C) Copyright 1999 Georg Acher, acher@in.tum.de
11  * (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
12  * (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
13  * (C) Copyright 2004 Alan Stern, stern@rowland.harvard.edu
14  */
15 
16 static const __u8 root_hub_hub_des[] =
17 {
18 	0x09,			/*  __u8  bLength; */
19 	USB_DT_HUB,		/*  __u8  bDescriptorType; Hub-descriptor */
20 	0x02,			/*  __u8  bNbrPorts; */
21 	HUB_CHAR_NO_LPSM |	/* __u16  wHubCharacteristics; */
22 		HUB_CHAR_INDV_PORT_OCPM, /* (per-port OC, no power switching) */
23 	0x00,
24 	0x01,			/*  __u8  bPwrOn2pwrGood; 2ms */
25 	0x00,			/*  __u8  bHubContrCurrent; 0 mA */
26 	0x00,			/*  __u8  DeviceRemovable; *** 7 Ports max */
27 	0xff			/*  __u8  PortPwrCtrlMask; *** 7 ports max */
28 };
29 
30 #define	UHCI_RH_MAXCHILD	7
31 
32 /* must write as zeroes */
33 #define WZ_BITS		(USBPORTSC_RES2 | USBPORTSC_RES3 | USBPORTSC_RES4)
34 
35 /* status change bits:  nonzero writes will clear */
36 #define RWC_BITS	(USBPORTSC_OCC | USBPORTSC_PEC | USBPORTSC_CSC)
37 
38 /* suspend/resume bits: port suspended or port resuming */
39 #define SUSPEND_BITS	(USBPORTSC_SUSP | USBPORTSC_RD)
40 
41 /* A port that either is connected or has a changed-bit set will prevent
42  * us from AUTO_STOPPING.
43  */
44 static int any_ports_active(struct uhci_hcd *uhci)
45 {
46 	int port;
47 
48 	for (port = 0; port < uhci->rh_numports; ++port) {
49 		if ((uhci_readw(uhci, USBPORTSC1 + port * 2) &
50 				(USBPORTSC_CCS | RWC_BITS)) ||
51 				test_bit(port, &uhci->port_c_suspend))
52 			return 1;
53 	}
54 	return 0;
55 }
56 
57 static inline int get_hub_status_data(struct uhci_hcd *uhci, char *buf)
58 {
59 	int port;
60 	int mask = RWC_BITS;
61 
62 	/* Some boards (both VIA and Intel apparently) report bogus
63 	 * overcurrent indications, causing massive log spam unless
64 	 * we completely ignore them.  This doesn't seem to be a problem
65 	 * with the chipset so much as with the way it is connected on
66 	 * the motherboard; if the overcurrent input is left to float
67 	 * then it may constantly register false positives. */
68 	if (ignore_oc)
69 		mask &= ~USBPORTSC_OCC;
70 
71 	*buf = 0;
72 	for (port = 0; port < uhci->rh_numports; ++port) {
73 		if ((uhci_readw(uhci, USBPORTSC1 + port * 2) & mask) ||
74 				test_bit(port, &uhci->port_c_suspend))
75 			*buf |= (1 << (port + 1));
76 	}
77 	return !!*buf;
78 }
79 
80 #define CLR_RH_PORTSTAT(x) \
81 	status = uhci_readw(uhci, port_addr);	\
82 	status &= ~(RWC_BITS|WZ_BITS); \
83 	status &= ~(x); \
84 	status |= RWC_BITS & (x); \
85 	uhci_writew(uhci, status, port_addr)
86 
87 #define SET_RH_PORTSTAT(x) \
88 	status = uhci_readw(uhci, port_addr);	\
89 	status |= (x); \
90 	status &= ~(RWC_BITS|WZ_BITS); \
91 	uhci_writew(uhci, status, port_addr)
92 
93 /* UHCI controllers don't automatically stop resume signalling after 20 msec,
94  * so we have to poll and check timeouts in order to take care of it.
95  */
96 static void uhci_finish_suspend(struct uhci_hcd *uhci, int port,
97 		unsigned long port_addr)
98 {
99 	int status;
100 	int i;
101 
102 	if (uhci_readw(uhci, port_addr) & SUSPEND_BITS) {
103 		CLR_RH_PORTSTAT(SUSPEND_BITS);
104 		if (test_bit(port, &uhci->resuming_ports))
105 			set_bit(port, &uhci->port_c_suspend);
106 
107 		/* The controller won't actually turn off the RD bit until
108 		 * it has had a chance to send a low-speed EOP sequence,
109 		 * which is supposed to take 3 bit times (= 2 microseconds).
110 		 * Experiments show that some controllers take longer, so
111 		 * we'll poll for completion. */
112 		for (i = 0; i < 10; ++i) {
113 			if (!(uhci_readw(uhci, port_addr) & SUSPEND_BITS))
114 				break;
115 			udelay(1);
116 		}
117 	}
118 	clear_bit(port, &uhci->resuming_ports);
119 	usb_hcd_end_port_resume(&uhci_to_hcd(uhci)->self, port);
120 }
121 
122 /* Wait for the UHCI controller in HP's iLO2 server management chip.
123  * It can take up to 250 us to finish a reset and set the CSC bit.
124  */
125 static void wait_for_HP(struct uhci_hcd *uhci, unsigned long port_addr)
126 {
127 	int i;
128 
129 	for (i = 10; i < 250; i += 10) {
130 		if (uhci_readw(uhci, port_addr) & USBPORTSC_CSC)
131 			return;
132 		udelay(10);
133 	}
134 	/* Log a warning? */
135 }
136 
137 static void uhci_check_ports(struct uhci_hcd *uhci)
138 {
139 	unsigned int port;
140 	unsigned long port_addr;
141 	int status;
142 
143 	for (port = 0; port < uhci->rh_numports; ++port) {
144 		port_addr = USBPORTSC1 + 2 * port;
145 		status = uhci_readw(uhci, port_addr);
146 		if (unlikely(status & USBPORTSC_PR)) {
147 			if (time_after_eq(jiffies, uhci->ports_timeout)) {
148 				CLR_RH_PORTSTAT(USBPORTSC_PR);
149 				udelay(10);
150 
151 				/* HP's server management chip requires
152 				 * a longer delay. */
153 				if (uhci->wait_for_hp)
154 					wait_for_HP(uhci, port_addr);
155 
156 				/* If the port was enabled before, turning
157 				 * reset on caused a port enable change.
158 				 * Turning reset off causes a port connect
159 				 * status change.  Clear these changes. */
160 				CLR_RH_PORTSTAT(USBPORTSC_CSC | USBPORTSC_PEC);
161 				SET_RH_PORTSTAT(USBPORTSC_PE);
162 			}
163 		}
164 		if (unlikely(status & USBPORTSC_RD)) {
165 			if (!test_bit(port, &uhci->resuming_ports)) {
166 
167 				/* Port received a wakeup request */
168 				set_bit(port, &uhci->resuming_ports);
169 				uhci->ports_timeout = jiffies +
170 					msecs_to_jiffies(USB_RESUME_TIMEOUT);
171 				usb_hcd_start_port_resume(
172 						&uhci_to_hcd(uhci)->self, port);
173 
174 				/* Make sure we see the port again
175 				 * after the resuming period is over. */
176 				mod_timer(&uhci_to_hcd(uhci)->rh_timer,
177 						uhci->ports_timeout);
178 			} else if (time_after_eq(jiffies,
179 						uhci->ports_timeout)) {
180 				uhci_finish_suspend(uhci, port, port_addr);
181 			}
182 		}
183 	}
184 }
185 
186 static int uhci_hub_status_data(struct usb_hcd *hcd, char *buf)
187 {
188 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
189 	unsigned long flags;
190 	int status = 0;
191 
192 	spin_lock_irqsave(&uhci->lock, flags);
193 
194 	uhci_scan_schedule(uhci);
195 	if (!HCD_HW_ACCESSIBLE(hcd) || uhci->dead)
196 		goto done;
197 	uhci_check_ports(uhci);
198 
199 	status = get_hub_status_data(uhci, buf);
200 
201 	switch (uhci->rh_state) {
202 	    case UHCI_RH_SUSPENDED:
203 		/* if port change, ask to be resumed */
204 		if (status || uhci->resuming_ports) {
205 			status = 1;
206 			usb_hcd_resume_root_hub(hcd);
207 		}
208 		break;
209 
210 	    case UHCI_RH_AUTO_STOPPED:
211 		/* if port change, auto start */
212 		if (status)
213 			wakeup_rh(uhci);
214 		break;
215 
216 	    case UHCI_RH_RUNNING:
217 		/* are any devices attached? */
218 		if (!any_ports_active(uhci)) {
219 			uhci->rh_state = UHCI_RH_RUNNING_NODEVS;
220 			uhci->auto_stop_time = jiffies + HZ;
221 		}
222 		break;
223 
224 	    case UHCI_RH_RUNNING_NODEVS:
225 		/* auto-stop if nothing connected for 1 second */
226 		if (any_ports_active(uhci))
227 			uhci->rh_state = UHCI_RH_RUNNING;
228 		else if (time_after_eq(jiffies, uhci->auto_stop_time) &&
229 				!uhci->wait_for_hp)
230 			suspend_rh(uhci, UHCI_RH_AUTO_STOPPED);
231 		break;
232 
233 	    default:
234 		break;
235 	}
236 
237 done:
238 	spin_unlock_irqrestore(&uhci->lock, flags);
239 	return status;
240 }
241 
242 /* size of returned buffer is part of USB spec */
243 static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
244 			u16 wIndex, char *buf, u16 wLength)
245 {
246 	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
247 	int status, lstatus, retval = 0;
248 	unsigned int port = wIndex - 1;
249 	unsigned long port_addr = USBPORTSC1 + 2 * port;
250 	u16 wPortChange, wPortStatus;
251 	unsigned long flags;
252 
253 	if (!HCD_HW_ACCESSIBLE(hcd) || uhci->dead)
254 		return -ETIMEDOUT;
255 
256 	spin_lock_irqsave(&uhci->lock, flags);
257 	switch (typeReq) {
258 
259 	case GetHubStatus:
260 		*(__le32 *)buf = cpu_to_le32(0);
261 		retval = 4; /* hub power */
262 		break;
263 	case GetPortStatus:
264 		if (port >= uhci->rh_numports)
265 			goto err;
266 
267 		uhci_check_ports(uhci);
268 		status = uhci_readw(uhci, port_addr);
269 
270 		/* Intel controllers report the OverCurrent bit active on.
271 		 * VIA controllers report it active off, so we'll adjust the
272 		 * bit value.  (It's not standardized in the UHCI spec.)
273 		 */
274 		if (uhci->oc_low)
275 			status ^= USBPORTSC_OC;
276 
277 		/* UHCI doesn't support C_RESET (always false) */
278 		wPortChange = lstatus = 0;
279 		if (status & USBPORTSC_CSC)
280 			wPortChange |= USB_PORT_STAT_C_CONNECTION;
281 		if (status & USBPORTSC_PEC)
282 			wPortChange |= USB_PORT_STAT_C_ENABLE;
283 		if ((status & USBPORTSC_OCC) && !ignore_oc)
284 			wPortChange |= USB_PORT_STAT_C_OVERCURRENT;
285 
286 		if (test_bit(port, &uhci->port_c_suspend)) {
287 			wPortChange |= USB_PORT_STAT_C_SUSPEND;
288 			lstatus |= 1;
289 		}
290 		if (test_bit(port, &uhci->resuming_ports))
291 			lstatus |= 4;
292 
293 		/* UHCI has no power switching (always on) */
294 		wPortStatus = USB_PORT_STAT_POWER;
295 		if (status & USBPORTSC_CCS)
296 			wPortStatus |= USB_PORT_STAT_CONNECTION;
297 		if (status & USBPORTSC_PE) {
298 			wPortStatus |= USB_PORT_STAT_ENABLE;
299 			if (status & SUSPEND_BITS)
300 				wPortStatus |= USB_PORT_STAT_SUSPEND;
301 		}
302 		if (status & USBPORTSC_OC)
303 			wPortStatus |= USB_PORT_STAT_OVERCURRENT;
304 		if (status & USBPORTSC_PR)
305 			wPortStatus |= USB_PORT_STAT_RESET;
306 		if (status & USBPORTSC_LSDA)
307 			wPortStatus |= USB_PORT_STAT_LOW_SPEED;
308 
309 		if (wPortChange)
310 			dev_dbg(uhci_dev(uhci), "port %d portsc %04x,%02x\n",
311 					wIndex, status, lstatus);
312 
313 		*(__le16 *)buf = cpu_to_le16(wPortStatus);
314 		*(__le16 *)(buf + 2) = cpu_to_le16(wPortChange);
315 		retval = 4;
316 		break;
317 	case SetHubFeature:		/* We don't implement these */
318 	case ClearHubFeature:
319 		switch (wValue) {
320 		case C_HUB_OVER_CURRENT:
321 		case C_HUB_LOCAL_POWER:
322 			break;
323 		default:
324 			goto err;
325 		}
326 		break;
327 	case SetPortFeature:
328 		if (port >= uhci->rh_numports)
329 			goto err;
330 
331 		switch (wValue) {
332 		case USB_PORT_FEAT_SUSPEND:
333 			SET_RH_PORTSTAT(USBPORTSC_SUSP);
334 			break;
335 		case USB_PORT_FEAT_RESET:
336 			SET_RH_PORTSTAT(USBPORTSC_PR);
337 
338 			/* Reset terminates Resume signalling */
339 			uhci_finish_suspend(uhci, port, port_addr);
340 
341 			/* USB v2.0 7.1.7.5 */
342 			uhci->ports_timeout = jiffies +
343 				msecs_to_jiffies(USB_RESUME_TIMEOUT);
344 			break;
345 		case USB_PORT_FEAT_POWER:
346 			/* UHCI has no power switching */
347 			break;
348 		default:
349 			goto err;
350 		}
351 		break;
352 	case ClearPortFeature:
353 		if (port >= uhci->rh_numports)
354 			goto err;
355 
356 		switch (wValue) {
357 		case USB_PORT_FEAT_ENABLE:
358 			CLR_RH_PORTSTAT(USBPORTSC_PE);
359 
360 			/* Disable terminates Resume signalling */
361 			uhci_finish_suspend(uhci, port, port_addr);
362 			break;
363 		case USB_PORT_FEAT_C_ENABLE:
364 			CLR_RH_PORTSTAT(USBPORTSC_PEC);
365 			break;
366 		case USB_PORT_FEAT_SUSPEND:
367 			if (!(uhci_readw(uhci, port_addr) & USBPORTSC_SUSP)) {
368 
369 				/* Make certain the port isn't suspended */
370 				uhci_finish_suspend(uhci, port, port_addr);
371 			} else if (!test_and_set_bit(port,
372 						&uhci->resuming_ports)) {
373 				SET_RH_PORTSTAT(USBPORTSC_RD);
374 
375 				/* The controller won't allow RD to be set
376 				 * if the port is disabled.  When this happens
377 				 * just skip the Resume signalling.
378 				 */
379 				if (!(uhci_readw(uhci, port_addr) &
380 						USBPORTSC_RD))
381 					uhci_finish_suspend(uhci, port,
382 							port_addr);
383 				else
384 					/* USB v2.0 7.1.7.7 */
385 					uhci->ports_timeout = jiffies +
386 						msecs_to_jiffies(20);
387 			}
388 			break;
389 		case USB_PORT_FEAT_C_SUSPEND:
390 			clear_bit(port, &uhci->port_c_suspend);
391 			break;
392 		case USB_PORT_FEAT_POWER:
393 			/* UHCI has no power switching */
394 			goto err;
395 		case USB_PORT_FEAT_C_CONNECTION:
396 			CLR_RH_PORTSTAT(USBPORTSC_CSC);
397 			break;
398 		case USB_PORT_FEAT_C_OVER_CURRENT:
399 			CLR_RH_PORTSTAT(USBPORTSC_OCC);
400 			break;
401 		case USB_PORT_FEAT_C_RESET:
402 			/* this driver won't report these */
403 			break;
404 		default:
405 			goto err;
406 		}
407 		break;
408 	case GetHubDescriptor:
409 		retval = min_t(unsigned int, sizeof(root_hub_hub_des), wLength);
410 		memcpy(buf, root_hub_hub_des, retval);
411 		if (retval > 2)
412 			buf[2] = uhci->rh_numports;
413 		break;
414 	default:
415 err:
416 		retval = -EPIPE;
417 	}
418 	spin_unlock_irqrestore(&uhci->lock, flags);
419 
420 	return retval;
421 }
422