summaryrefslogtreecommitdiff
path: root/drivers/thunderbolt/acpi.c
blob: 35fa17f7e59983f90ec022b9415f95d212542148 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
// SPDX-License-Identifier: GPL-2.0
/*
 * ACPI support
 *
 * Copyright (C) 2020, Intel Corporation
 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
 */

#include <linux/acpi.h>

#include "tb.h"

static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
				    void **return_value)
{
	struct fwnode_reference_args args;
	struct fwnode_handle *fwnode;
	struct tb_nhi *nhi = data;
	struct acpi_device *adev;
	struct pci_dev *pdev;
	struct device *dev;
	int ret;

	if (acpi_bus_get_device(handle, &adev))
		return AE_OK;

	fwnode = acpi_fwnode_handle(adev);
	ret = fwnode_property_get_reference_args(fwnode, "usb4-host-interface",
						 NULL, 0, 0, &args);
	if (ret)
		return AE_OK;

	/* It needs to reference this NHI */
	if (nhi->pdev->dev.fwnode != args.fwnode)
		goto out_put;

	/*
	 * Try to find physical device walking upwards to the hierarcy.
	 * We need to do this because the xHCI driver might not yet be
	 * bound so the USB3 SuperSpeed ports are not yet created.
	 */
	dev = acpi_get_first_physical_node(adev);
	while (!dev) {
		adev = adev->parent;
		if (!adev)
			break;
		dev = acpi_get_first_physical_node(adev);
	}

	if (!dev)
		goto out_put;

	/*
	 * Check that the device is PCIe. This is because USB3
	 * SuperSpeed ports have this property and they are not power
	 * managed with the xHCI and the SuperSpeed hub so we create the
	 * link from xHCI instead.
	 */
	while (dev && !dev_is_pci(dev))
		dev = dev->parent;

	if (!dev)
		goto out_put;

	/*
	 * Check that this actually matches the type of device we
	 * expect. It should either be xHCI or PCIe root/downstream
	 * port.
	 */
	pdev = to_pci_dev(dev);
	if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI ||
	    (pci_is_pcie(pdev) &&
		(pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
		 pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM))) {
		const struct device_link *link;

		link = device_link_add(&pdev->dev, &nhi->pdev->dev,
				       DL_FLAG_AUTOREMOVE_SUPPLIER |
				       DL_FLAG_PM_RUNTIME);
		if (link) {
			dev_dbg(&nhi->pdev->dev, "created link from %s\n",
				dev_name(&pdev->dev));
		} else {
			dev_warn(&nhi->pdev->dev, "device link creation from %s failed\n",
				 dev_name(&pdev->dev));
		}
	}

out_put:
	fwnode_handle_put(args.fwnode);
	return AE_OK;
}

/**
 * tb_acpi_add_links() - Add device links based on ACPI description
 * @nhi: Pointer to NHI
 *
 * Goes over ACPI namespace finding tunneled ports that reference to
 * @nhi ACPI node. For each reference a device link is added. The link
 * is automatically removed by the driver core.
 */
void tb_acpi_add_links(struct tb_nhi *nhi)
{
	acpi_status status;

	if (!has_acpi_companion(&nhi->pdev->dev))
		return;

	/*
	 * Find all devices that have usb4-host-controller interface
	 * property that references to this NHI.
	 */
	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 32,
				     tb_acpi_add_link, NULL, nhi, NULL);
	if (ACPI_FAILURE(status))
		dev_warn(&nhi->pdev->dev, "failed to enumerate tunneled ports\n");
}

/**
 * tb_acpi_is_native() - Did the platform grant native TBT/USB4 control
 *
 * Returns %true if the platform granted OS native control over
 * TBT/USB4. In this case software based connection manager can be used,
 * otherwise there is firmware based connection manager running.
 */
bool tb_acpi_is_native(void)
{
	return osc_sb_native_usb4_support_confirmed &&
	       osc_sb_native_usb4_control;
}

/**
 * tb_acpi_may_tunnel_usb3() - Is USB3 tunneling allowed by the platform
 *
 * When software based connection manager is used, this function
 * returns %true if platform allows native USB3 tunneling.
 */
bool tb_acpi_may_tunnel_usb3(void)
{
	if (tb_acpi_is_native())
		return osc_sb_native_usb4_control & OSC_USB_USB3_TUNNELING;
	return true;
}

/**
 * tb_acpi_may_tunnel_dp() - Is DisplayPort tunneling allowed by the platform
 *
 * When software based connection manager is used, this function
 * returns %true if platform allows native DP tunneling.
 */
bool tb_acpi_may_tunnel_dp(void)
{
	if (tb_acpi_is_native())
		return osc_sb_native_usb4_control & OSC_USB_DP_TUNNELING;
	return true;
}

/**
 * tb_acpi_may_tunnel_pcie() - Is PCIe tunneling allowed by the platform
 *
 * When software based connection manager is used, this function
 * returns %true if platform allows native PCIe tunneling.
 */
bool tb_acpi_may_tunnel_pcie(void)
{
	if (tb_acpi_is_native())
		return osc_sb_native_usb4_control & OSC_USB_PCIE_TUNNELING;
	return true;
}

/**
 * tb_acpi_is_xdomain_allowed() - Are XDomain connections allowed
 *
 * When software based connection manager is used, this function
 * returns %true if platform allows XDomain connections.
 */
bool tb_acpi_is_xdomain_allowed(void)
{
	if (tb_acpi_is_native())
		return osc_sb_native_usb4_control & OSC_USB_XDOMAIN;
	return true;
}