xref: /openbmc/linux/drivers/usb/core/hcd-pci.c (revision 87c2ce3b)
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 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/pci.h>
23 #include <linux/usb.h>
24 
25 #include <asm/io.h>
26 #include <asm/irq.h>
27 
28 #ifdef CONFIG_PPC_PMAC
29 #include <asm/machdep.h>
30 #include <asm/pmac_feature.h>
31 #include <asm/pci-bridge.h>
32 #include <asm/prom.h>
33 #endif
34 
35 #include "usb.h"
36 #include "hcd.h"
37 
38 
39 /* PCI-based HCs are common, but plenty of non-PCI HCs are used too */
40 
41 
42 /*-------------------------------------------------------------------------*/
43 
44 /* configure so an HC device and id are always provided */
45 /* always called with process context; sleeping is OK */
46 
47 /**
48  * usb_hcd_pci_probe - initialize PCI-based HCDs
49  * @dev: USB Host Controller being probed
50  * @id: pci hotplug id connecting controller to HCD framework
51  * Context: !in_interrupt()
52  *
53  * Allocates basic PCI resources for this USB host controller, and
54  * then invokes the start() method for the HCD associated with it
55  * through the hotplug entry's driver_data.
56  *
57  * Store this function in the HCD's struct pci_driver as probe().
58  */
59 int usb_hcd_pci_probe (struct pci_dev *dev, const struct pci_device_id *id)
60 {
61 	struct hc_driver	*driver;
62 	struct usb_hcd		*hcd;
63 	int			retval;
64 
65 	if (usb_disabled())
66 		return -ENODEV;
67 
68 	if (!id || !(driver = (struct hc_driver *) id->driver_data))
69 		return -EINVAL;
70 
71 	if (pci_enable_device (dev) < 0)
72 		return -ENODEV;
73 	dev->current_state = PCI_D0;
74 	dev->dev.power.power_state = PMSG_ON;
75 
76         if (!dev->irq) {
77         	dev_err (&dev->dev,
78 			"Found HC with no IRQ.  Check BIOS/PCI %s setup!\n",
79 			pci_name(dev));
80    	        retval = -ENODEV;
81 		goto err1;
82         }
83 
84 	hcd = usb_create_hcd (driver, &dev->dev, pci_name(dev));
85 	if (!hcd) {
86 		retval = -ENOMEM;
87 		goto err1;
88 	}
89 
90 	if (driver->flags & HCD_MEMORY) {	// EHCI, OHCI
91 		hcd->rsrc_start = pci_resource_start (dev, 0);
92 		hcd->rsrc_len = pci_resource_len (dev, 0);
93 		if (!request_mem_region (hcd->rsrc_start, hcd->rsrc_len,
94 				driver->description)) {
95 			dev_dbg (&dev->dev, "controller already in use\n");
96 			retval = -EBUSY;
97 			goto err2;
98 		}
99 		hcd->regs = ioremap_nocache (hcd->rsrc_start, hcd->rsrc_len);
100 		if (hcd->regs == NULL) {
101 			dev_dbg (&dev->dev, "error mapping memory\n");
102 			retval = -EFAULT;
103 			goto err3;
104 		}
105 
106 	} else { 				// UHCI
107 		int	region;
108 
109 		for (region = 0; region < PCI_ROM_RESOURCE; region++) {
110 			if (!(pci_resource_flags (dev, region) &
111 					IORESOURCE_IO))
112 				continue;
113 
114 			hcd->rsrc_start = pci_resource_start (dev, region);
115 			hcd->rsrc_len = pci_resource_len (dev, region);
116 			if (request_region (hcd->rsrc_start, hcd->rsrc_len,
117 					driver->description))
118 				break;
119 		}
120 		if (region == PCI_ROM_RESOURCE) {
121 			dev_dbg (&dev->dev, "no i/o regions available\n");
122 			retval = -EBUSY;
123 			goto err1;
124 		}
125 	}
126 
127 	pci_set_master (dev);
128 
129 	retval = usb_add_hcd (hcd, dev->irq, SA_SHIRQ);
130 	if (retval != 0)
131 		goto err4;
132 	return retval;
133 
134  err4:
135 	if (driver->flags & HCD_MEMORY) {
136 		iounmap (hcd->regs);
137  err3:
138 		release_mem_region (hcd->rsrc_start, hcd->rsrc_len);
139 	} else
140 		release_region (hcd->rsrc_start, hcd->rsrc_len);
141  err2:
142 	usb_put_hcd (hcd);
143  err1:
144 	pci_disable_device (dev);
145 	dev_err (&dev->dev, "init %s fail, %d\n", pci_name(dev), retval);
146 	return retval;
147 }
148 EXPORT_SYMBOL (usb_hcd_pci_probe);
149 
150 
151 /* may be called without controller electrically present */
152 /* may be called with controller, bus, and devices active */
153 
154 /**
155  * usb_hcd_pci_remove - shutdown processing for PCI-based HCDs
156  * @dev: USB Host Controller being removed
157  * Context: !in_interrupt()
158  *
159  * Reverses the effect of usb_hcd_pci_probe(), first invoking
160  * the HCD's stop() method.  It is always called from a thread
161  * context, normally "rmmod", "apmd", or something similar.
162  *
163  * Store this function in the HCD's struct pci_driver as remove().
164  */
165 void usb_hcd_pci_remove (struct pci_dev *dev)
166 {
167 	struct usb_hcd		*hcd;
168 
169 	hcd = pci_get_drvdata(dev);
170 	if (!hcd)
171 		return;
172 
173 	usb_remove_hcd (hcd);
174 	if (hcd->driver->flags & HCD_MEMORY) {
175 		iounmap (hcd->regs);
176 		release_mem_region (hcd->rsrc_start, hcd->rsrc_len);
177 	} else {
178 		release_region (hcd->rsrc_start, hcd->rsrc_len);
179 	}
180 	usb_put_hcd (hcd);
181 	pci_disable_device(dev);
182 }
183 EXPORT_SYMBOL (usb_hcd_pci_remove);
184 
185 
186 #ifdef	CONFIG_PM
187 
188 /**
189  * usb_hcd_pci_suspend - power management suspend of a PCI-based HCD
190  * @dev: USB Host Controller being suspended
191  * @message: semantics in flux
192  *
193  * Store this function in the HCD's struct pci_driver as suspend().
194  */
195 int usb_hcd_pci_suspend (struct pci_dev *dev, pm_message_t message)
196 {
197 	struct usb_hcd		*hcd;
198 	int			retval = 0;
199 	int			has_pci_pm;
200 
201 	hcd = pci_get_drvdata(dev);
202 
203 	/* Root hub suspend should have stopped all downstream traffic,
204 	 * and all bus master traffic.  And done so for both the interface
205 	 * and the stub usb_device (which we check here).  But maybe it
206 	 * didn't; writing sysfs power/state files ignores such rules...
207 	 *
208 	 * We must ignore the FREEZE vs SUSPEND distinction here, because
209 	 * otherwise the swsusp will save (and restore) garbage state.
210 	 */
211 	if (hcd->self.root_hub->dev.power.power_state.event == PM_EVENT_ON)
212 		return -EBUSY;
213 
214 	if (hcd->driver->suspend) {
215 		retval = hcd->driver->suspend(hcd, message);
216 		if (retval) {
217 			dev_dbg (&dev->dev, "PCI pre-suspend fail, %d\n",
218 				retval);
219 			goto done;
220 		}
221 	}
222 	synchronize_irq(dev->irq);
223 
224 	/* FIXME until the generic PM interfaces change a lot more, this
225 	 * can't use PCI D1 and D2 states.  For example, the confusion
226 	 * between messages and states will need to vanish, and messages
227 	 * will need to provide a target system state again.
228 	 *
229 	 * It'll be important to learn characteristics of the target state,
230 	 * especially on embedded hardware where the HCD will often be in
231 	 * charge of an external VBUS power supply and one or more clocks.
232 	 * Some target system states will leave them active; others won't.
233 	 * (With PCI, that's often handled by platform BIOS code.)
234 	 */
235 
236 	/* even when the PCI layer rejects some of the PCI calls
237 	 * below, HCs can try global suspend and reduce DMA traffic.
238 	 * PM-sensitive HCDs may already have done this.
239 	 */
240 	has_pci_pm = pci_find_capability(dev, PCI_CAP_ID_PM);
241 
242 	/* Downstream ports from this root hub should already be quiesced, so
243 	 * there will be no DMA activity.  Now we can shut down the upstream
244 	 * link (except maybe for PME# resume signaling) and enter some PCI
245 	 * low power state, if the hardware allows.
246 	 */
247 	if (hcd->state == HC_STATE_SUSPENDED) {
248 
249 		/* no DMA or IRQs except when HC is active */
250 		if (dev->current_state == PCI_D0) {
251 			pci_save_state (dev);
252 			pci_disable_device (dev);
253 		}
254 
255 		if (!has_pci_pm) {
256 			dev_dbg (hcd->self.controller, "--> PCI D0/legacy\n");
257 			goto done;
258 		}
259 
260 		/* NOTE:  dev->current_state becomes nonzero only here, and
261 		 * only for devices that support PCI PM.  Also, exiting
262 		 * PCI_D3 (but not PCI_D1 or PCI_D2) is allowed to reset
263 		 * some device state (e.g. as part of clock reinit).
264 		 */
265 		retval = pci_set_power_state (dev, PCI_D3hot);
266 		if (retval == 0) {
267 			dev_dbg (hcd->self.controller, "--> PCI D3\n");
268 
269 			/* Ignore these return values.  We rely on pci code to
270 			 * reject requests the hardware can't implement, rather
271 			 * than coding the same thing.
272 			 */
273 			(void) pci_enable_wake (dev, PCI_D3hot, hcd->remote_wakeup);
274 			(void) pci_enable_wake (dev, PCI_D3cold, hcd->remote_wakeup);
275 		} else {
276 			dev_dbg (&dev->dev, "PCI D3 suspend fail, %d\n",
277 					retval);
278 			(void) usb_hcd_pci_resume (dev);
279 		}
280 
281 	} else {
282 		dev_dbg (hcd->self.controller, "hcd state %d; not suspended\n",
283 			hcd->state);
284 		WARN_ON(1);
285 		retval = -EINVAL;
286 	}
287 
288 done:
289 	if (retval == 0) {
290 		dev->dev.power.power_state = PMSG_SUSPEND;
291 
292 #ifdef CONFIG_PPC_PMAC
293 		/* Disable ASIC clocks for USB */
294 		if (_machine == _MACH_Pmac) {
295 			struct device_node	*of_node;
296 
297 			of_node = pci_device_to_OF_node (dev);
298 			if (of_node)
299 				pmac_call_feature(PMAC_FTR_USB_ENABLE,
300 							of_node, 0, 0);
301 		}
302 #endif
303 	}
304 
305 	return retval;
306 }
307 EXPORT_SYMBOL (usb_hcd_pci_suspend);
308 
309 /**
310  * usb_hcd_pci_resume - power management resume of a PCI-based HCD
311  * @dev: USB Host Controller being resumed
312  *
313  * Store this function in the HCD's struct pci_driver as resume().
314  */
315 int usb_hcd_pci_resume (struct pci_dev *dev)
316 {
317 	struct usb_hcd		*hcd;
318 	int			retval;
319 
320 	hcd = pci_get_drvdata(dev);
321 	if (hcd->state != HC_STATE_SUSPENDED) {
322 		dev_dbg (hcd->self.controller,
323 				"can't resume, not suspended!\n");
324 		return 0;
325 	}
326 
327 #ifdef CONFIG_PPC_PMAC
328 	/* Reenable ASIC clocks for USB */
329 	if (_machine == _MACH_Pmac) {
330 		struct device_node *of_node;
331 
332 		of_node = pci_device_to_OF_node (dev);
333 		if (of_node)
334 			pmac_call_feature (PMAC_FTR_USB_ENABLE,
335 						of_node, 0, 1);
336 	}
337 #endif
338 
339 	/* NOTE:  chip docs cover clean "real suspend" cases (what Linux
340 	 * calls "standby", "suspend to RAM", and so on).  There are also
341 	 * dirty cases when swsusp fakes a suspend in "shutdown" mode.
342 	 */
343 	if (dev->current_state != PCI_D0) {
344 #ifdef	DEBUG
345 		int	pci_pm;
346 		u16	pmcr;
347 
348 		pci_pm = pci_find_capability(dev, PCI_CAP_ID_PM);
349 		pci_read_config_word(dev, pci_pm + PCI_PM_CTRL, &pmcr);
350 		pmcr &= PCI_PM_CTRL_STATE_MASK;
351 		if (pmcr) {
352 			/* Clean case:  power to USB and to HC registers was
353 			 * maintained; remote wakeup is easy.
354 			 */
355 			dev_dbg(hcd->self.controller, "resume from PCI D%d\n",
356 					pmcr);
357 		} else {
358 			/* Clean:  HC lost Vcc power, D0 uninitialized
359 			 *   + Vaux may have preserved port and transceiver
360 			 *     state ... for remote wakeup from D3cold
361 			 *   + or not; HCD must reinit + re-enumerate
362 			 *
363 			 * Dirty: D0 semi-initialized cases with swsusp
364 			 *   + after BIOS init
365 			 *   + after Linux init (HCD statically linked)
366 			 */
367 			dev_dbg(hcd->self.controller,
368 				"PCI D0, from previous PCI D%d\n",
369 				dev->current_state);
370 		}
371 #endif
372 		/* yes, ignore these results too... */
373 		(void) pci_enable_wake (dev, dev->current_state, 0);
374 		(void) pci_enable_wake (dev, PCI_D3cold, 0);
375 	} else {
376 		/* Same basic cases: clean (powered/not), dirty */
377 		dev_dbg(hcd->self.controller, "PCI legacy resume\n");
378 	}
379 
380 	/* NOTE:  the PCI API itself is asymmetric here.  We don't need to
381 	 * pci_set_power_state(PCI_D0) since that's part of re-enabling;
382 	 * but that won't re-enable bus mastering.  Yet pci_disable_device()
383 	 * explicitly disables bus mastering...
384 	 */
385 	retval = pci_enable_device (dev);
386 	if (retval < 0) {
387 		dev_err (hcd->self.controller,
388 			"can't re-enable after resume, %d!\n", retval);
389 		return retval;
390 	}
391 	pci_set_master (dev);
392 	pci_restore_state (dev);
393 
394 	dev->dev.power.power_state = PMSG_ON;
395 
396 	clear_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
397 
398 	if (hcd->driver->resume) {
399 		retval = hcd->driver->resume(hcd);
400 		if (retval) {
401 			dev_err (hcd->self.controller,
402 				"PCI post-resume error %d!\n", retval);
403 			usb_hc_died (hcd);
404 		}
405 	}
406 
407 	return retval;
408 }
409 EXPORT_SYMBOL (usb_hcd_pci_resume);
410 
411 #endif	/* CONFIG_PM */
412 
413 
414