xref: /openbmc/linux/drivers/usb/host/xhci-ext-caps.h (revision 25985edc)
1 /*
2  * xHCI host controller driver
3  *
4  * Copyright (C) 2008 Intel Corp.
5  *
6  * Author: Sarah Sharp
7  * Some code borrowed from the Linux EHCI driver.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16  * for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software Foundation,
20  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 /* Up to 16 ms to halt an HC */
23 #define XHCI_MAX_HALT_USEC	(16*1000)
24 /* HC not running - set to 1 when run/stop bit is cleared. */
25 #define XHCI_STS_HALT		(1<<0)
26 
27 /* HCCPARAMS offset from PCI base address */
28 #define XHCI_HCC_PARAMS_OFFSET	0x10
29 /* HCCPARAMS contains the first extended capability pointer */
30 #define XHCI_HCC_EXT_CAPS(p)	(((p)>>16)&0xffff)
31 
32 /* Command and Status registers offset from the Operational Registers address */
33 #define XHCI_CMD_OFFSET		0x00
34 #define XHCI_STS_OFFSET		0x04
35 
36 #define XHCI_MAX_EXT_CAPS		50
37 
38 /* Capability Register */
39 /* bits 7:0 - how long is the Capabilities register */
40 #define XHCI_HC_LENGTH(p)	(((p)>>00)&0x00ff)
41 
42 /* Extended capability register fields */
43 #define XHCI_EXT_CAPS_ID(p)	(((p)>>0)&0xff)
44 #define XHCI_EXT_CAPS_NEXT(p)	(((p)>>8)&0xff)
45 #define	XHCI_EXT_CAPS_VAL(p)	((p)>>16)
46 /* Extended capability IDs - ID 0 reserved */
47 #define XHCI_EXT_CAPS_LEGACY	1
48 #define XHCI_EXT_CAPS_PROTOCOL	2
49 #define XHCI_EXT_CAPS_PM	3
50 #define XHCI_EXT_CAPS_VIRT	4
51 #define XHCI_EXT_CAPS_ROUTE	5
52 /* IDs 6-9 reserved */
53 #define XHCI_EXT_CAPS_DEBUG	10
54 /* USB Legacy Support Capability - section 7.1.1 */
55 #define XHCI_HC_BIOS_OWNED	(1 << 16)
56 #define XHCI_HC_OS_OWNED	(1 << 24)
57 
58 /* USB Legacy Support Capability - section 7.1.1 */
59 /* Add this offset, plus the value of xECP in HCCPARAMS to the base address */
60 #define XHCI_LEGACY_SUPPORT_OFFSET	(0x00)
61 
62 /* USB Legacy Support Control and Status Register  - section 7.1.2 */
63 /* Add this offset, plus the value of xECP in HCCPARAMS to the base address */
64 #define XHCI_LEGACY_CONTROL_OFFSET	(0x04)
65 /* bits 1:2, 5:12, and 17:19 need to be preserved; bits 21:28 should be zero */
66 #define	XHCI_LEGACY_DISABLE_SMI		((0x3 << 1) + (0xff << 5) + (0x7 << 17))
67 
68 /* command register values to disable interrupts and halt the HC */
69 /* start/stop HC execution - do not write unless HC is halted*/
70 #define XHCI_CMD_RUN		(1 << 0)
71 /* Event Interrupt Enable - get irq when EINT bit is set in USBSTS register */
72 #define XHCI_CMD_EIE		(1 << 2)
73 /* Host System Error Interrupt Enable - get irq when HSEIE bit set in USBSTS */
74 #define XHCI_CMD_HSEIE		(1 << 3)
75 /* Enable Wrap Event - '1' means xHC generates an event when MFINDEX wraps. */
76 #define XHCI_CMD_EWE		(1 << 10)
77 
78 #define XHCI_IRQS		(XHCI_CMD_EIE | XHCI_CMD_HSEIE | XHCI_CMD_EWE)
79 
80 /* true: Controller Not Ready to accept doorbell or op reg writes after reset */
81 #define XHCI_STS_CNR		(1 << 11)
82 
83 #include <linux/io.h>
84 
85 /**
86  * Return the next extended capability pointer register.
87  *
88  * @base	PCI register base address.
89  *
90  * @ext_offset	Offset of the 32-bit register that contains the extended
91  * capabilites pointer.  If searching for the first extended capability, pass
92  * in XHCI_HCC_PARAMS_OFFSET.  If searching for the next extended capability,
93  * pass in the offset of the current extended capability register.
94  *
95  * Returns 0 if there is no next extended capability register or returns the register offset
96  * from the PCI registers base address.
97  */
98 static inline int xhci_find_next_cap_offset(void __iomem *base, int ext_offset)
99 {
100 	u32 next;
101 
102 	next = readl(base + ext_offset);
103 
104 	if (ext_offset == XHCI_HCC_PARAMS_OFFSET) {
105 		/* Find the first extended capability */
106 		next = XHCI_HCC_EXT_CAPS(next);
107 		ext_offset = 0;
108 	} else {
109 		/* Find the next extended capability */
110 		next = XHCI_EXT_CAPS_NEXT(next);
111 	}
112 
113 	if (!next)
114 		return 0;
115 	/*
116 	 * Address calculation from offset of extended capabilities
117 	 * (or HCCPARAMS) register - see section 5.3.6 and section 7.
118 	 */
119 	return ext_offset + (next << 2);
120 }
121 
122 /**
123  * Find the offset of the extended capabilities with capability ID id.
124  *
125  * @base PCI MMIO registers base address.
126  * @ext_offset Offset from base of the first extended capability to look at,
127  * 		or the address of HCCPARAMS.
128  * @id Extended capability ID to search for.
129  *
130  * This uses an arbitrary limit of XHCI_MAX_EXT_CAPS extended capabilities
131  * to make sure that the list doesn't contain a loop.
132  */
133 static inline int xhci_find_ext_cap_by_id(void __iomem *base, int ext_offset, int id)
134 {
135 	u32 val;
136 	int limit = XHCI_MAX_EXT_CAPS;
137 
138 	while (ext_offset && limit > 0) {
139 		val = readl(base + ext_offset);
140 		if (XHCI_EXT_CAPS_ID(val) == id)
141 			break;
142 		ext_offset = xhci_find_next_cap_offset(base, ext_offset);
143 		limit--;
144 	}
145 	if (limit > 0)
146 		return ext_offset;
147 	return 0;
148 }
149