xref: /linux/drivers/usb/core/hcd-pci.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
1 /*
2  * (C) Copyright David Brownell 2000-2002
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License as published by the
6  * Free Software Foundation; either version 2 of the License, or (at your
7  * option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software Foundation,
16  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18 
19 #include <linux/config.h>
20 
21 #ifdef CONFIG_USB_DEBUG
22 	#define DEBUG
23 #else
24 	#undef DEBUG
25 #endif
26 
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/pci.h>
30 #include <asm/io.h>
31 #include <asm/irq.h>
32 #include <linux/usb.h>
33 
34 #include "usb.h"
35 #include "hcd.h"
36 
37 
38 /* PCI-based HCs are common, but plenty of non-PCI HCs are used too */
39 
40 
41 /*-------------------------------------------------------------------------*/
42 
43 /* configure so an HC device and id are always provided */
44 /* always called with process context; sleeping is OK */
45 
46 /**
47  * usb_hcd_pci_probe - initialize PCI-based HCDs
48  * @dev: USB Host Controller being probed
49  * @id: pci hotplug id connecting controller to HCD framework
50  * Context: !in_interrupt()
51  *
52  * Allocates basic PCI resources for this USB host controller, and
53  * then invokes the start() method for the HCD associated with it
54  * through the hotplug entry's driver_data.
55  *
56  * Store this function in the HCD's struct pci_driver as probe().
57  */
58 int usb_hcd_pci_probe (struct pci_dev *dev, const struct pci_device_id *id)
59 {
60 	struct hc_driver	*driver;
61 	struct usb_hcd		*hcd;
62 	int			retval;
63 
64 	if (usb_disabled())
65 		return -ENODEV;
66 
67 	if (!id || !(driver = (struct hc_driver *) id->driver_data))
68 		return -EINVAL;
69 
70 	if (pci_enable_device (dev) < 0)
71 		return -ENODEV;
72 	dev->current_state = PCI_D0;
73 	dev->dev.power.power_state = PMSG_ON;
74 
75         if (!dev->irq) {
76         	dev_err (&dev->dev,
77 			"Found HC with no IRQ.  Check BIOS/PCI %s setup!\n",
78 			pci_name(dev));
79    	        retval = -ENODEV;
80 		goto err1;
81         }
82 
83 	hcd = usb_create_hcd (driver, &dev->dev, pci_name(dev));
84 	if (!hcd) {
85 		retval = -ENOMEM;
86 		goto err1;
87 	}
88 
89 	if (driver->flags & HCD_MEMORY) {	// EHCI, OHCI
90 		hcd->rsrc_start = pci_resource_start (dev, 0);
91 		hcd->rsrc_len = pci_resource_len (dev, 0);
92 		if (!request_mem_region (hcd->rsrc_start, hcd->rsrc_len,
93 				driver->description)) {
94 			dev_dbg (&dev->dev, "controller already in use\n");
95 			retval = -EBUSY;
96 			goto err2;
97 		}
98 		hcd->regs = ioremap_nocache (hcd->rsrc_start, hcd->rsrc_len);
99 		if (hcd->regs == NULL) {
100 			dev_dbg (&dev->dev, "error mapping memory\n");
101 			retval = -EFAULT;
102 			goto err3;
103 		}
104 
105 	} else { 				// UHCI
106 		int	region;
107 
108 		for (region = 0; region < PCI_ROM_RESOURCE; region++) {
109 			if (!(pci_resource_flags (dev, region) &
110 					IORESOURCE_IO))
111 				continue;
112 
113 			hcd->rsrc_start = pci_resource_start (dev, region);
114 			hcd->rsrc_len = pci_resource_len (dev, region);
115 			if (request_region (hcd->rsrc_start, hcd->rsrc_len,
116 					driver->description))
117 				break;
118 		}
119 		if (region == PCI_ROM_RESOURCE) {
120 			dev_dbg (&dev->dev, "no i/o regions available\n");
121 			retval = -EBUSY;
122 			goto err1;
123 		}
124 	}
125 
126 	pci_set_master (dev);
127 
128 	retval = usb_add_hcd (hcd, dev->irq, SA_SHIRQ);
129 	if (retval != 0)
130 		goto err4;
131 	return retval;
132 
133  err4:
134 	if (driver->flags & HCD_MEMORY) {
135 		iounmap (hcd->regs);
136  err3:
137 		release_mem_region (hcd->rsrc_start, hcd->rsrc_len);
138 	} else
139 		release_region (hcd->rsrc_start, hcd->rsrc_len);
140  err2:
141 	usb_put_hcd (hcd);
142  err1:
143 	pci_disable_device (dev);
144 	dev_err (&dev->dev, "init %s fail, %d\n", pci_name(dev), retval);
145 	return retval;
146 }
147 EXPORT_SYMBOL (usb_hcd_pci_probe);
148 
149 
150 /* may be called without controller electrically present */
151 /* may be called with controller, bus, and devices active */
152 
153 /**
154  * usb_hcd_pci_remove - shutdown processing for PCI-based HCDs
155  * @dev: USB Host Controller being removed
156  * Context: !in_interrupt()
157  *
158  * Reverses the effect of usb_hcd_pci_probe(), first invoking
159  * the HCD's stop() method.  It is always called from a thread
160  * context, normally "rmmod", "apmd", or something similar.
161  *
162  * Store this function in the HCD's struct pci_driver as remove().
163  */
164 void usb_hcd_pci_remove (struct pci_dev *dev)
165 {
166 	struct usb_hcd		*hcd;
167 
168 	hcd = pci_get_drvdata(dev);
169 	if (!hcd)
170 		return;
171 
172 	usb_remove_hcd (hcd);
173 	if (hcd->driver->flags & HCD_MEMORY) {
174 		iounmap (hcd->regs);
175 		release_mem_region (hcd->rsrc_start, hcd->rsrc_len);
176 	} else {
177 		release_region (hcd->rsrc_start, hcd->rsrc_len);
178 	}
179 	usb_put_hcd (hcd);
180 	pci_disable_device(dev);
181 }
182 EXPORT_SYMBOL (usb_hcd_pci_remove);
183 
184 
185 #ifdef	CONFIG_PM
186 
187 /**
188  * usb_hcd_pci_suspend - power management suspend of a PCI-based HCD
189  * @dev: USB Host Controller being suspended
190  * @message: semantics in flux
191  *
192  * Store this function in the HCD's struct pci_driver as suspend().
193  */
194 int usb_hcd_pci_suspend (struct pci_dev *dev, pm_message_t message)
195 {
196 	struct usb_hcd		*hcd;
197 	int			retval = 0;
198 	int			has_pci_pm;
199 
200 	hcd = pci_get_drvdata(dev);
201 
202 	/* Root hub suspend should have stopped all downstream traffic,
203 	 * and all bus master traffic.  And done so for both the interface
204 	 * and the stub usb_device (which we check here).  But maybe it
205 	 * didn't; writing sysfs power/state files ignores such rules...
206 	 *
207 	 * We must ignore the FREEZE vs SUSPEND distinction here, because
208 	 * otherwise the swsusp will save (and restore) garbage state.
209 	 */
210 	if (hcd->self.root_hub->dev.power.power_state.event == PM_EVENT_ON)
211 		return -EBUSY;
212 
213 	if (hcd->driver->suspend) {
214 		retval = hcd->driver->suspend(hcd, message);
215 		if (retval) {
216 			dev_dbg (&dev->dev, "PCI pre-suspend fail, %d\n",
217 				retval);
218 			goto done;
219 		}
220 	}
221 
222 	/* FIXME until the generic PM interfaces change a lot more, this
223 	 * can't use PCI D1 and D2 states.  For example, the confusion
224 	 * between messages and states will need to vanish, and messages
225 	 * will need to provide a target system state again.
226 	 *
227 	 * It'll be important to learn characteristics of the target state,
228 	 * especially on embedded hardware where the HCD will often be in
229 	 * charge of an external VBUS power supply and one or more clocks.
230 	 * Some target system states will leave them active; others won't.
231 	 * (With PCI, that's often handled by platform BIOS code.)
232 	 */
233 
234 	/* even when the PCI layer rejects some of the PCI calls
235 	 * below, HCs can try global suspend and reduce DMA traffic.
236 	 * PM-sensitive HCDs may already have done this.
237 	 */
238 	has_pci_pm = pci_find_capability(dev, PCI_CAP_ID_PM);
239 
240 	/* Downstream ports from this root hub should already be quiesced, so
241 	 * there will be no DMA activity.  Now we can shut down the upstream
242 	 * link (except maybe for PME# resume signaling) and enter some PCI
243 	 * low power state, if the hardware allows.
244 	 */
245 	if (hcd->state == HC_STATE_SUSPENDED) {
246 
247 		/* no DMA or IRQs except when HC is active */
248 		if (dev->current_state == PCI_D0) {
249 			pci_save_state (dev);
250 			pci_disable_device (dev);
251 		}
252 
253 		if (!has_pci_pm) {
254 			dev_dbg (hcd->self.controller, "--> PCI D0/legacy\n");
255 			goto done;
256 		}
257 
258 		/* NOTE:  dev->current_state becomes nonzero only here, and
259 		 * only for devices that support PCI PM.  Also, exiting
260 		 * PCI_D3 (but not PCI_D1 or PCI_D2) is allowed to reset
261 		 * some device state (e.g. as part of clock reinit).
262 		 */
263 		retval = pci_set_power_state (dev, PCI_D3hot);
264 		if (retval == 0) {
265 			dev_dbg (hcd->self.controller, "--> PCI D3\n");
266 
267 			/* Ignore these return values.  We rely on pci code to
268 			 * reject requests the hardware can't implement, rather
269 			 * than coding the same thing.
270 			 */
271 			(void) pci_enable_wake (dev, PCI_D3hot, hcd->remote_wakeup);
272 			(void) pci_enable_wake (dev, PCI_D3cold, hcd->remote_wakeup);
273 		} else {
274 			dev_dbg (&dev->dev, "PCI D3 suspend fail, %d\n",
275 					retval);
276 			(void) usb_hcd_pci_resume (dev);
277 		}
278 
279 	} else {
280 		dev_dbg (hcd->self.controller, "hcd state %d; not suspended\n",
281 			hcd->state);
282 		WARN_ON(1);
283 		retval = -EINVAL;
284 	}
285 
286 done:
287 	if (retval == 0)
288 		dev->dev.power.power_state = PMSG_SUSPEND;
289 	return retval;
290 }
291 EXPORT_SYMBOL (usb_hcd_pci_suspend);
292 
293 /**
294  * usb_hcd_pci_resume - power management resume of a PCI-based HCD
295  * @dev: USB Host Controller being resumed
296  *
297  * Store this function in the HCD's struct pci_driver as resume().
298  */
299 int usb_hcd_pci_resume (struct pci_dev *dev)
300 {
301 	struct usb_hcd		*hcd;
302 	int			retval;
303 
304 	hcd = pci_get_drvdata(dev);
305 	if (hcd->state != HC_STATE_SUSPENDED) {
306 		dev_dbg (hcd->self.controller,
307 				"can't resume, not suspended!\n");
308 		return 0;
309 	}
310 
311 	/* NOTE:  chip docs cover clean "real suspend" cases (what Linux
312 	 * calls "standby", "suspend to RAM", and so on).  There are also
313 	 * dirty cases when swsusp fakes a suspend in "shutdown" mode.
314 	 */
315 	if (dev->current_state != PCI_D0) {
316 #ifdef	DEBUG
317 		int	pci_pm;
318 		u16	pmcr;
319 
320 		pci_pm = pci_find_capability(dev, PCI_CAP_ID_PM);
321 		pci_read_config_word(dev, pci_pm + PCI_PM_CTRL, &pmcr);
322 		pmcr &= PCI_PM_CTRL_STATE_MASK;
323 		if (pmcr) {
324 			/* Clean case:  power to USB and to HC registers was
325 			 * maintained; remote wakeup is easy.
326 			 */
327 			dev_dbg(hcd->self.controller, "resume from PCI D%d\n",
328 					pmcr);
329 		} else {
330 			/* Clean:  HC lost Vcc power, D0 uninitialized
331 			 *   + Vaux may have preserved port and transceiver
332 			 *     state ... for remote wakeup from D3cold
333 			 *   + or not; HCD must reinit + re-enumerate
334 			 *
335 			 * Dirty: D0 semi-initialized cases with swsusp
336 			 *   + after BIOS init
337 			 *   + after Linux init (HCD statically linked)
338 			 */
339 			dev_dbg(hcd->self.controller,
340 				"PCI D0, from previous PCI D%d\n",
341 				dev->current_state);
342 		}
343 #endif
344 		/* yes, ignore these results too... */
345 		(void) pci_enable_wake (dev, dev->current_state, 0);
346 		(void) pci_enable_wake (dev, PCI_D3cold, 0);
347 	} else {
348 		/* Same basic cases: clean (powered/not), dirty */
349 		dev_dbg(hcd->self.controller, "PCI legacy resume\n");
350 	}
351 
352 	/* NOTE:  the PCI API itself is asymmetric here.  We don't need to
353 	 * pci_set_power_state(PCI_D0) since that's part of re-enabling;
354 	 * but that won't re-enable bus mastering.  Yet pci_disable_device()
355 	 * explicitly disables bus mastering...
356 	 */
357 	retval = pci_enable_device (dev);
358 	if (retval < 0) {
359 		dev_err (hcd->self.controller,
360 			"can't re-enable after resume, %d!\n", retval);
361 		return retval;
362 	}
363 	pci_set_master (dev);
364 	pci_restore_state (dev);
365 
366 	dev->dev.power.power_state = PMSG_ON;
367 
368 	hcd->saw_irq = 0;
369 
370 	if (hcd->driver->resume) {
371 		retval = hcd->driver->resume(hcd);
372 		if (retval) {
373 			dev_err (hcd->self.controller,
374 				"PCI post-resume error %d!\n", retval);
375 			usb_hc_died (hcd);
376 		}
377 	}
378 
379 	return retval;
380 }
381 EXPORT_SYMBOL (usb_hcd_pci_resume);
382 
383 #endif	/* CONFIG_PM */
384 
385 
386