xref: /openbmc/linux/drivers/usb/host/pci-quirks.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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/types.h>
12 #include <linux/kernel.h>
13 #include <linux/pci.h>
14 #include <linux/init.h>
15 #include <linux/delay.h>
16 #include <linux/acpi.h>
17 #include "pci-quirks.h"
18 
19 
20 #define UHCI_USBLEGSUP		0xc0		/* legacy support */
21 #define UHCI_USBCMD		0		/* command register */
22 #define UHCI_USBINTR		4		/* interrupt register */
23 #define UHCI_USBLEGSUP_RWC	0x8f00		/* the R/WC bits */
24 #define UHCI_USBLEGSUP_RO	0x5040		/* R/O and reserved bits */
25 #define UHCI_USBCMD_RUN		0x0001		/* RUN/STOP bit */
26 #define UHCI_USBCMD_HCRESET	0x0002		/* Host Controller reset */
27 #define UHCI_USBCMD_EGSM	0x0008		/* Global Suspend Mode */
28 #define UHCI_USBCMD_CONFIGURE	0x0040		/* Config Flag */
29 #define UHCI_USBINTR_RESUME	0x0002		/* Resume interrupt enable */
30 
31 #define OHCI_CONTROL		0x04
32 #define OHCI_CMDSTATUS		0x08
33 #define OHCI_INTRSTATUS		0x0c
34 #define OHCI_INTRENABLE		0x10
35 #define OHCI_INTRDISABLE	0x14
36 #define OHCI_OCR		(1 << 3)	/* ownership change request */
37 #define OHCI_CTRL_RWC		(1 << 9)	/* remote wakeup connected */
38 #define OHCI_CTRL_IR		(1 << 8)	/* interrupt routing */
39 #define OHCI_INTR_OC		(1 << 30)	/* ownership change */
40 
41 #define EHCI_HCC_PARAMS		0x08		/* extended capabilities */
42 #define EHCI_USBCMD		0		/* command register */
43 #define EHCI_USBCMD_RUN		(1 << 0)	/* RUN/STOP bit */
44 #define EHCI_USBSTS		4		/* status register */
45 #define EHCI_USBSTS_HALTED	(1 << 12)	/* HCHalted bit */
46 #define EHCI_USBINTR		8		/* interrupt register */
47 #define EHCI_CONFIGFLAG		0x40		/* configured flag 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 
172 	if (!mmio_resource_enabled(pdev, 0))
173 		return;
174 
175 	base = ioremap_nocache(pci_resource_start(pdev, 0),
176 				     pci_resource_len(pdev, 0));
177 	if (base == NULL) return;
178 
179 /* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
180 #ifndef __hppa__
181 {
182 	u32 control = readl(base + OHCI_CONTROL);
183 	if (control & OHCI_CTRL_IR) {
184 		int wait_time = 500; /* arbitrary; 5 seconds */
185 		writel(OHCI_INTR_OC, base + OHCI_INTRENABLE);
186 		writel(OHCI_OCR, base + OHCI_CMDSTATUS);
187 		while (wait_time > 0 &&
188 				readl(base + OHCI_CONTROL) & OHCI_CTRL_IR) {
189 			wait_time -= 10;
190 			msleep(10);
191 		}
192 		if (wait_time <= 0)
193 			printk(KERN_WARNING "%s %s: BIOS handoff "
194 					"failed (BIOS bug ?) %08x\n",
195 					pdev->dev.bus_id, "OHCI",
196 					readl(base + OHCI_CONTROL));
197 
198 		/* reset controller, preserving RWC */
199 		writel(control & OHCI_CTRL_RWC, base + OHCI_CONTROL);
200 	}
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 	int	tried_handoff = 0;
221 
222 	if (!mmio_resource_enabled(pdev, 0))
223 		return;
224 
225 	base = ioremap_nocache(pci_resource_start(pdev, 0),
226 				pci_resource_len(pdev, 0));
227 	if (base == NULL) return;
228 
229 	cap_length = readb(base);
230 	op_reg_base = base + cap_length;
231 
232 	/* EHCI 0.96 and later may have "extended capabilities"
233 	 * spec section 5.1 explains the bios handoff, e.g. for
234 	 * booting from USB disk or using a usb keyboard
235 	 */
236 	hcc_params = readl(base + EHCI_HCC_PARAMS);
237 	offset = (hcc_params >> 8) & 0xff;
238 	while (offset && count--) {
239 		u32		cap;
240 		int		msec;
241 
242 		pci_read_config_dword(pdev, offset, &cap);
243 		switch (cap & 0xff) {
244 		case 1:			/* BIOS/SMM/... handoff support */
245 			if ((cap & EHCI_USBLEGSUP_BIOS)) {
246 				pr_debug("%s %s: BIOS handoff\n",
247 						pdev->dev.bus_id, "EHCI");
248 
249 #if 0
250 /* aleksey_gorelov@phoenix.com reports that some systems need SMI forced on,
251  * but that seems dubious in general (the BIOS left it off intentionally)
252  * and is known to prevent some systems from booting.  so we won't do this
253  * unless maybe we can determine when we're on a system that needs SMI forced.
254  */
255 				/* BIOS workaround (?): be sure the
256 				 * pre-Linux code receives the SMI
257 				 */
258 				pci_read_config_dword(pdev,
259 						offset + EHCI_USBLEGCTLSTS,
260 						&val);
261 				pci_write_config_dword(pdev,
262 						offset + EHCI_USBLEGCTLSTS,
263 						val | EHCI_USBLEGCTLSTS_SOOE);
264 #endif
265 
266 				/* some systems get upset if this semaphore is
267 				 * set for any other reason than forcing a BIOS
268 				 * handoff..
269 				 */
270 				pci_write_config_byte(pdev, offset + 3, 1);
271 			}
272 
273 			/* if boot firmware now owns EHCI, spin till
274 			 * it hands it over.
275 			 */
276 			msec = 5000;
277 			while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
278 				tried_handoff = 1;
279 				msleep(10);
280 				msec -= 10;
281 				pci_read_config_dword(pdev, offset, &cap);
282 			}
283 
284 			if (cap & EHCI_USBLEGSUP_BIOS) {
285 				/* well, possibly buggy BIOS... try to shut
286 				 * it down, and hope nothing goes too wrong
287 				 */
288 				printk(KERN_WARNING "%s %s: BIOS handoff "
289 						"failed (BIOS bug ?) %08x\n",
290 					pdev->dev.bus_id, "EHCI", cap);
291 				pci_write_config_byte(pdev, offset + 2, 0);
292 			}
293 
294 			/* just in case, always disable EHCI SMIs */
295 			pci_write_config_dword(pdev,
296 					offset + EHCI_USBLEGCTLSTS,
297 					0);
298 
299 			/* If the BIOS ever owned the controller then we
300 			 * can't expect any power sessions to remain intact.
301 			 */
302 			if (tried_handoff)
303 				writel(0, op_reg_base + EHCI_CONFIGFLAG);
304 			break;
305 		case 0:			/* illegal reserved capability */
306 			cap = 0;
307 			/* FALLTHROUGH */
308 		default:
309 			printk(KERN_WARNING "%s %s: unrecognized "
310 					"capability %02x\n",
311 					pdev->dev.bus_id, "EHCI",
312 					cap & 0xff);
313 			break;
314 		}
315 		offset = (cap >> 8) & 0xff;
316 	}
317 	if (!count)
318 		printk(KERN_DEBUG "%s %s: capability loop?\n",
319 				pdev->dev.bus_id, "EHCI");
320 
321 	/*
322 	 * halt EHCI & disable its interrupts in any case
323 	 */
324 	val = readl(op_reg_base + EHCI_USBSTS);
325 	if ((val & EHCI_USBSTS_HALTED) == 0) {
326 		val = readl(op_reg_base + EHCI_USBCMD);
327 		val &= ~EHCI_USBCMD_RUN;
328 		writel(val, op_reg_base + EHCI_USBCMD);
329 
330 		wait_time = 2000;
331 		delta = 100;
332 		do {
333 			writel(0x3f, op_reg_base + EHCI_USBSTS);
334 			udelay(delta);
335 			wait_time -= delta;
336 			val = readl(op_reg_base + EHCI_USBSTS);
337 			if ((val == ~(u32)0) || (val & EHCI_USBSTS_HALTED)) {
338 				break;
339 			}
340 		} while (wait_time > 0);
341 	}
342 	writel(0, op_reg_base + EHCI_USBINTR);
343 	writel(0x3f, op_reg_base + EHCI_USBSTS);
344 
345 	iounmap(base);
346 
347 	return;
348 }
349 
350 
351 
352 static void __devinit quirk_usb_early_handoff(struct pci_dev *pdev)
353 {
354 	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
355 		quirk_usb_handoff_uhci(pdev);
356 	else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
357 		quirk_usb_handoff_ohci(pdev);
358 	else if (pdev->class == PCI_CLASS_SERIAL_USB_EHCI)
359 		quirk_usb_disable_ehci(pdev);
360 }
361 DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, quirk_usb_early_handoff);
362