xref: /linux/drivers/usb/host/pci-quirks.c (revision 7b12b9137930eb821b68e1bfa11e9de692208620)
1 /*
2  * This file contains code to reset and initialize USB host controllers.
3  * Some of it includes work-arounds for PCI hardware and BIOS quirks.
4  * It may need to run early during booting -- before USB would normally
5  * initialize -- to ensure that Linux doesn't use any legacy modes.
6  *
7  *  Copyright (c) 1999 Martin Mares <mj@ucw.cz>
8  *  (and others)
9  */
10 
11 #include <linux/config.h>
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/pci.h>
15 #include <linux/init.h>
16 #include <linux/delay.h>
17 #include <linux/acpi.h>
18 #include "pci-quirks.h"
19 
20 
21 #define UHCI_USBLEGSUP		0xc0		/* legacy support */
22 #define UHCI_USBCMD		0		/* command register */
23 #define UHCI_USBINTR		4		/* interrupt register */
24 #define UHCI_USBLEGSUP_RWC	0x8f00		/* the R/WC bits */
25 #define UHCI_USBLEGSUP_RO	0x5040		/* R/O and reserved bits */
26 #define UHCI_USBCMD_RUN		0x0001		/* RUN/STOP bit */
27 #define UHCI_USBCMD_HCRESET	0x0002		/* Host Controller reset */
28 #define UHCI_USBCMD_EGSM	0x0008		/* Global Suspend Mode */
29 #define UHCI_USBCMD_CONFIGURE	0x0040		/* Config Flag */
30 #define UHCI_USBINTR_RESUME	0x0002		/* Resume interrupt enable */
31 
32 #define OHCI_CONTROL		0x04
33 #define OHCI_CMDSTATUS		0x08
34 #define OHCI_INTRSTATUS		0x0c
35 #define OHCI_INTRENABLE		0x10
36 #define OHCI_INTRDISABLE	0x14
37 #define OHCI_OCR		(1 << 3)	/* ownership change request */
38 #define OHCI_CTRL_RWC		(1 << 9)	/* remote wakeup connected */
39 #define OHCI_CTRL_IR		(1 << 8)	/* interrupt routing */
40 #define OHCI_INTR_OC		(1 << 30)	/* ownership change */
41 
42 #define EHCI_HCC_PARAMS		0x08		/* extended capabilities */
43 #define EHCI_USBCMD		0		/* command register */
44 #define EHCI_USBCMD_RUN		(1 << 0)	/* RUN/STOP bit */
45 #define EHCI_USBSTS		4		/* status register */
46 #define EHCI_USBSTS_HALTED	(1 << 12)	/* HCHalted bit */
47 #define EHCI_USBINTR		8		/* interrupt register */
48 #define EHCI_USBLEGSUP		0		/* legacy support register */
49 #define EHCI_USBLEGSUP_BIOS	(1 << 16)	/* BIOS semaphore */
50 #define EHCI_USBLEGSUP_OS	(1 << 24)	/* OS semaphore */
51 #define EHCI_USBLEGCTLSTS	4		/* legacy control/status */
52 #define EHCI_USBLEGCTLSTS_SOOE	(1 << 13)	/* SMI on ownership change */
53 
54 
55 /*
56  * Make sure the controller is completely inactive, unable to
57  * generate interrupts or do DMA.
58  */
59 void uhci_reset_hc(struct pci_dev *pdev, unsigned long base)
60 {
61 	/* Turn off PIRQ enable and SMI enable.  (This also turns off the
62 	 * BIOS's USB Legacy Support.)  Turn off all the R/WC bits too.
63 	 */
64 	pci_write_config_word(pdev, UHCI_USBLEGSUP, UHCI_USBLEGSUP_RWC);
65 
66 	/* Reset the HC - this will force us to get a
67 	 * new notification of any already connected
68 	 * ports due to the virtual disconnect that it
69 	 * implies.
70 	 */
71 	outw(UHCI_USBCMD_HCRESET, base + UHCI_USBCMD);
72 	mb();
73 	udelay(5);
74 	if (inw(base + UHCI_USBCMD) & UHCI_USBCMD_HCRESET)
75 		dev_warn(&pdev->dev, "HCRESET not completed yet!\n");
76 
77 	/* Just to be safe, disable interrupt requests and
78 	 * make sure the controller is stopped.
79 	 */
80 	outw(0, base + UHCI_USBINTR);
81 	outw(0, base + UHCI_USBCMD);
82 }
83 EXPORT_SYMBOL_GPL(uhci_reset_hc);
84 
85 /*
86  * Initialize a controller that was newly discovered or has just been
87  * resumed.  In either case we can't be sure of its previous state.
88  *
89  * Returns: 1 if the controller was reset, 0 otherwise.
90  */
91 int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base)
92 {
93 	u16 legsup;
94 	unsigned int cmd, intr;
95 
96 	/*
97 	 * When restarting a suspended controller, we expect all the
98 	 * settings to be the same as we left them:
99 	 *
100 	 *	PIRQ and SMI disabled, no R/W bits set in USBLEGSUP;
101 	 *	Controller is stopped and configured with EGSM set;
102 	 *	No interrupts enabled except possibly Resume Detect.
103 	 *
104 	 * If any of these conditions are violated we do a complete reset.
105 	 */
106 	pci_read_config_word(pdev, UHCI_USBLEGSUP, &legsup);
107 	if (legsup & ~(UHCI_USBLEGSUP_RO | UHCI_USBLEGSUP_RWC)) {
108 		dev_dbg(&pdev->dev, "%s: legsup = 0x%04x\n",
109 				__FUNCTION__, legsup);
110 		goto reset_needed;
111 	}
112 
113 	cmd = inw(base + UHCI_USBCMD);
114 	if ((cmd & UHCI_USBCMD_RUN) || !(cmd & UHCI_USBCMD_CONFIGURE) ||
115 			!(cmd & UHCI_USBCMD_EGSM)) {
116 		dev_dbg(&pdev->dev, "%s: cmd = 0x%04x\n",
117 				__FUNCTION__, cmd);
118 		goto reset_needed;
119 	}
120 
121 	intr = inw(base + UHCI_USBINTR);
122 	if (intr & (~UHCI_USBINTR_RESUME)) {
123 		dev_dbg(&pdev->dev, "%s: intr = 0x%04x\n",
124 				__FUNCTION__, intr);
125 		goto reset_needed;
126 	}
127 	return 0;
128 
129 reset_needed:
130 	dev_dbg(&pdev->dev, "Performing full reset\n");
131 	uhci_reset_hc(pdev, base);
132 	return 1;
133 }
134 EXPORT_SYMBOL_GPL(uhci_check_and_reset_hc);
135 
136 static inline int io_type_enabled(struct pci_dev *pdev, unsigned int mask)
137 {
138 	u16 cmd;
139 	return !pci_read_config_word(pdev, PCI_COMMAND, &cmd) && (cmd & mask);
140 }
141 
142 #define pio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_IO)
143 #define mmio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_MEMORY)
144 
145 static void __devinit quirk_usb_handoff_uhci(struct pci_dev *pdev)
146 {
147 	unsigned long base = 0;
148 	int i;
149 
150 	if (!pio_enabled(pdev))
151 		return;
152 
153 	for (i = 0; i < PCI_ROM_RESOURCE; i++)
154 		if ((pci_resource_flags(pdev, i) & IORESOURCE_IO)) {
155 			base = pci_resource_start(pdev, i);
156 			break;
157 		}
158 
159 	if (base)
160 		uhci_check_and_reset_hc(pdev, base);
161 }
162 
163 static int __devinit mmio_resource_enabled(struct pci_dev *pdev, int idx)
164 {
165 	return pci_resource_start(pdev, idx) && mmio_enabled(pdev);
166 }
167 
168 static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)
169 {
170 	void __iomem *base;
171 	int wait_time;
172 	u32 control;
173 
174 	if (!mmio_resource_enabled(pdev, 0))
175 		return;
176 
177 	base = ioremap_nocache(pci_resource_start(pdev, 0),
178 				     pci_resource_len(pdev, 0));
179 	if (base == NULL) return;
180 
181 /* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
182 #ifndef __hppa__
183 	control = readl(base + OHCI_CONTROL);
184 	if (control & OHCI_CTRL_IR) {
185 		wait_time = 500; /* arbitrary; 5 seconds */
186 		writel(OHCI_INTR_OC, base + OHCI_INTRENABLE);
187 		writel(OHCI_OCR, base + OHCI_CMDSTATUS);
188 		while (wait_time > 0 &&
189 				readl(base + OHCI_CONTROL) & OHCI_CTRL_IR) {
190 			wait_time -= 10;
191 			msleep(10);
192 		}
193 		if (wait_time <= 0)
194 			printk(KERN_WARNING "%s %s: BIOS handoff "
195 					"failed (BIOS bug ?) %08x\n",
196 					pdev->dev.bus_id, "OHCI",
197 					readl(base + OHCI_CONTROL));
198 
199 		/* reset controller, preserving RWC */
200 		writel(control & OHCI_CTRL_RWC, base + OHCI_CONTROL);
201 	}
202 #endif
203 
204 	/*
205 	 * disable interrupts
206 	 */
207 	writel(~(u32)0, base + OHCI_INTRDISABLE);
208 	writel(~(u32)0, base + OHCI_INTRSTATUS);
209 
210 	iounmap(base);
211 }
212 
213 static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
214 {
215 	int wait_time, delta;
216 	void __iomem *base, *op_reg_base;
217 	u32	hcc_params, val;
218 	u8	offset, cap_length;
219 	int	count = 256/4;
220 
221 	if (!mmio_resource_enabled(pdev, 0))
222 		return;
223 
224 	base = ioremap_nocache(pci_resource_start(pdev, 0),
225 				pci_resource_len(pdev, 0));
226 	if (base == NULL) return;
227 
228 	cap_length = readb(base);
229 	op_reg_base = base + cap_length;
230 
231 	/* EHCI 0.96 and later may have "extended capabilities"
232 	 * spec section 5.1 explains the bios handoff, e.g. for
233 	 * booting from USB disk or using a usb keyboard
234 	 */
235 	hcc_params = readl(base + EHCI_HCC_PARAMS);
236 	offset = (hcc_params >> 8) & 0xff;
237 	while (offset && count--) {
238 		u32		cap;
239 		int		msec;
240 
241 		pci_read_config_dword(pdev, offset, &cap);
242 		switch (cap & 0xff) {
243 		case 1:			/* BIOS/SMM/... handoff support */
244 			if ((cap & EHCI_USBLEGSUP_BIOS)) {
245 				pr_debug("%s %s: BIOS handoff\n",
246 						pdev->dev.bus_id, "EHCI");
247 
248 #if 0
249 /* aleksey_gorelov@phoenix.com reports that some systems need SMI forced on,
250  * but that seems dubious in general (the BIOS left it off intentionally)
251  * and is known to prevent some systems from booting.  so we won't do this
252  * unless maybe we can determine when we're on a system that needs SMI forced.
253  */
254 				/* BIOS workaround (?): be sure the
255 				 * pre-Linux code receives the SMI
256 				 */
257 				pci_read_config_dword(pdev,
258 						offset + EHCI_USBLEGCTLSTS,
259 						&val);
260 				pci_write_config_dword(pdev,
261 						offset + EHCI_USBLEGCTLSTS,
262 						val | EHCI_USBLEGCTLSTS_SOOE);
263 #endif
264 
265 				/* some systems get upset if this semaphore is
266 				 * set for any other reason than forcing a BIOS
267 				 * handoff..
268 				 */
269 				pci_write_config_byte(pdev, offset + 3, 1);
270 			}
271 
272 			/* if boot firmware now owns EHCI, spin till
273 			 * it hands it over.
274 			 */
275 			msec = 5000;
276 			while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
277 				msleep(10);
278 				msec -= 10;
279 				pci_read_config_dword(pdev, offset, &cap);
280 			}
281 
282 			if (cap & EHCI_USBLEGSUP_BIOS) {
283 				/* well, possibly buggy BIOS... try to shut
284 				 * it down, and hope nothing goes too wrong
285 				 */
286 				printk(KERN_WARNING "%s %s: BIOS handoff "
287 						"failed (BIOS bug ?) %08x\n",
288 					pdev->dev.bus_id, "EHCI", cap);
289 				pci_write_config_byte(pdev, offset + 2, 0);
290 			}
291 
292 			/* just in case, always disable EHCI SMIs */
293 			pci_write_config_dword(pdev,
294 					offset + EHCI_USBLEGCTLSTS,
295 					0);
296 			break;
297 		case 0:			/* illegal reserved capability */
298 			cap = 0;
299 			/* FALLTHROUGH */
300 		default:
301 			printk(KERN_WARNING "%s %s: unrecognized "
302 					"capability %02x\n",
303 					pdev->dev.bus_id, "EHCI",
304 					cap & 0xff);
305 			break;
306 		}
307 		offset = (cap >> 8) & 0xff;
308 	}
309 	if (!count)
310 		printk(KERN_DEBUG "%s %s: capability loop?\n",
311 				pdev->dev.bus_id, "EHCI");
312 
313 	/*
314 	 * halt EHCI & disable its interrupts in any case
315 	 */
316 	val = readl(op_reg_base + EHCI_USBSTS);
317 	if ((val & EHCI_USBSTS_HALTED) == 0) {
318 		val = readl(op_reg_base + EHCI_USBCMD);
319 		val &= ~EHCI_USBCMD_RUN;
320 		writel(val, op_reg_base + EHCI_USBCMD);
321 
322 		wait_time = 2000;
323 		delta = 100;
324 		do {
325 			writel(0x3f, op_reg_base + EHCI_USBSTS);
326 			udelay(delta);
327 			wait_time -= delta;
328 			val = readl(op_reg_base + EHCI_USBSTS);
329 			if ((val == ~(u32)0) || (val & EHCI_USBSTS_HALTED)) {
330 				break;
331 			}
332 		} while (wait_time > 0);
333 	}
334 	writel(0, op_reg_base + EHCI_USBINTR);
335 	writel(0x3f, op_reg_base + EHCI_USBSTS);
336 
337 	iounmap(base);
338 
339 	return;
340 }
341 
342 
343 
344 static void __devinit quirk_usb_early_handoff(struct pci_dev *pdev)
345 {
346 	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
347 		quirk_usb_handoff_uhci(pdev);
348 	else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
349 		quirk_usb_handoff_ohci(pdev);
350 	else if (pdev->class == PCI_CLASS_SERIAL_USB_EHCI)
351 		quirk_usb_disable_ehci(pdev);
352 }
353 DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, quirk_usb_early_handoff);
354