summaryrefslogtreecommitdiff
path: root/drivers/thunderbolt/acpi.c
blob: 628225deb8fef2f0b44cb95205edebdd246ea021 (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
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
// 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 <linux/pm_runtime.h>

#include "tb.h"

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

	if (!adev)
		return AE_OK;

	fwnode = fwnode_find_reference(acpi_fwnode_handle(adev), "usb4-host-interface", 0);
	if (IS_ERR(fwnode))
		return AE_OK;

	/* It needs to reference this NHI */
	if (dev_fwnode(&nhi->pdev->dev) != 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.
	 */
	do {
		dev = acpi_get_first_physical_node(adev);
		if (dev)
			break;

		adev = acpi_dev_parent(adev);
	} while (adev);

	/*
	 * 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;

		/*
		 * Make them both active first to make sure the NHI does
		 * not runtime suspend before the consumer. The
		 * pm_runtime_put() below then allows the consumer to
		 * runtime suspend again (which then allows NHI runtime
		 * suspend too now that the device link is established).
		 */
		pm_runtime_get_sync(&pdev->dev);

		link = device_link_add(&pdev->dev, &nhi->pdev->dev,
				       DL_FLAG_AUTOREMOVE_SUPPLIER |
				       DL_FLAG_RPM_ACTIVE |
				       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));
		}

		pm_runtime_put(&pdev->dev);
	}

out_put:
	fwnode_handle_put(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;
}

/* UUID for retimer _DSM: e0053122-795b-4122-8a5e-57be1d26acb3 */
static const guid_t retimer_dsm_guid =
	GUID_INIT(0xe0053122, 0x795b, 0x4122,
		  0x8a, 0x5e, 0x57, 0xbe, 0x1d, 0x26, 0xac, 0xb3);

#define RETIMER_DSM_QUERY_ONLINE_STATE	1
#define RETIMER_DSM_SET_ONLINE_STATE	2

static int tb_acpi_retimer_set_power(struct tb_port *port, bool power)
{
	struct usb4_port *usb4 = port->usb4;
	union acpi_object argv4[2];
	struct acpi_device *adev;
	union acpi_object *obj;
	int ret;

	if (!usb4->can_offline)
		return 0;

	adev = ACPI_COMPANION(&usb4->dev);
	if (WARN_ON(!adev))
		return 0;

	/* Check if we are already powered on (and in correct mode) */
	obj = acpi_evaluate_dsm_typed(adev->handle, &retimer_dsm_guid, 1,
				      RETIMER_DSM_QUERY_ONLINE_STATE, NULL,
				      ACPI_TYPE_INTEGER);
	if (!obj) {
		tb_port_warn(port, "ACPI: query online _DSM failed\n");
		return -EIO;
	}

	ret = obj->integer.value;
	ACPI_FREE(obj);

	if (power == ret)
		return 0;

	tb_port_dbg(port, "ACPI: calling _DSM to power %s retimers\n",
		    power ? "on" : "off");

	argv4[0].type = ACPI_TYPE_PACKAGE;
	argv4[0].package.count = 1;
	argv4[0].package.elements = &argv4[1];
	argv4[1].integer.type = ACPI_TYPE_INTEGER;
	argv4[1].integer.value = power;

	obj = acpi_evaluate_dsm_typed(adev->handle, &retimer_dsm_guid, 1,
				      RETIMER_DSM_SET_ONLINE_STATE, argv4,
				      ACPI_TYPE_INTEGER);
	if (!obj) {
		tb_port_warn(port,
			     "ACPI: set online state _DSM evaluation failed\n");
		return -EIO;
	}

	ret = obj->integer.value;
	ACPI_FREE(obj);

	if (ret >= 0) {
		if (power)
			return ret == 1 ? 0 : -EBUSY;
		return 0;
	}

	tb_port_warn(port, "ACPI: set online state _DSM failed with error %d\n", ret);
	return -EIO;
}

/**
 * tb_acpi_power_on_retimers() - Call platform to power on retimers
 * @port: USB4 port
 *
 * Calls platform to turn on power to all retimers behind this USB4
 * port. After this function returns successfully the caller can
 * continue with the normal retimer flows (as specified in the USB4
 * spec). Note if this returns %-EBUSY it means the type-C port is in
 * non-USB4/TBT mode (there is non-USB4/TBT device connected).
 *
 * This should only be called if the USB4/TBT link is not up.
 *
 * Returns %0 on success.
 */
int tb_acpi_power_on_retimers(struct tb_port *port)
{
	return tb_acpi_retimer_set_power(port, true);
}

/**
 * tb_acpi_power_off_retimers() - Call platform to power off retimers
 * @port: USB4 port
 *
 * This is the opposite of tb_acpi_power_on_retimers(). After returning
 * successfully the normal operations with the @port can continue.
 *
 * Returns %0 on success.
 */
int tb_acpi_power_off_retimers(struct tb_port *port)
{
	return tb_acpi_retimer_set_power(port, false);
}

static bool tb_acpi_bus_match(struct device *dev)
{
	return tb_is_switch(dev) || tb_is_usb4_port_device(dev);
}

static struct acpi_device *tb_acpi_switch_find_companion(struct tb_switch *sw)
{
	struct acpi_device *adev = NULL;
	struct tb_switch *parent_sw;

	/*
	 * Device routers exists under the downstream facing USB4 port
	 * of the parent router. Their _ADR is always 0.
	 */
	parent_sw = tb_switch_parent(sw);
	if (parent_sw) {
		struct tb_port *port = tb_port_at(tb_route(sw), parent_sw);
		struct acpi_device *port_adev;

		port_adev = acpi_find_child_by_adr(ACPI_COMPANION(&parent_sw->dev),
						   port->port);
		if (port_adev)
			adev = acpi_find_child_device(port_adev, 0, false);
	} else {
		struct tb_nhi *nhi = sw->tb->nhi;
		struct acpi_device *parent_adev;

		parent_adev = ACPI_COMPANION(&nhi->pdev->dev);
		if (parent_adev)
			adev = acpi_find_child_device(parent_adev, 0, false);
	}

	return adev;
}

static struct acpi_device *tb_acpi_find_companion(struct device *dev)
{
	/*
	 * The Thunderbolt/USB4 hierarchy looks like following:
	 *
	 * Device (NHI)
	 *   Device (HR)		// Host router _ADR == 0
	 *      Device (DFP0)		// Downstream port _ADR == lane 0 adapter
	 *        Device (DR)		// Device router _ADR == 0
	 *          Device (UFP)	// Upstream port _ADR == lane 0 adapter
	 *      Device (DFP1)		// Downstream port _ADR == lane 0 adapter number
	 *
	 * At the moment we bind the host router to the corresponding
	 * Linux device.
	 */
	if (tb_is_switch(dev))
		return tb_acpi_switch_find_companion(tb_to_switch(dev));
	else if (tb_is_usb4_port_device(dev))
		return acpi_find_child_by_adr(ACPI_COMPANION(dev->parent),
					      tb_to_usb4_port_device(dev)->port->port);
	return NULL;
}

static void tb_acpi_setup(struct device *dev)
{
	struct acpi_device *adev = ACPI_COMPANION(dev);
	struct usb4_port *usb4 = tb_to_usb4_port_device(dev);

	if (!adev || !usb4)
		return;

	if (acpi_check_dsm(adev->handle, &retimer_dsm_guid, 1,
			   BIT(RETIMER_DSM_QUERY_ONLINE_STATE) |
			   BIT(RETIMER_DSM_SET_ONLINE_STATE)))
		usb4->can_offline = true;
}

static struct acpi_bus_type tb_acpi_bus = {
	.name = "thunderbolt",
	.match = tb_acpi_bus_match,
	.find_companion = tb_acpi_find_companion,
	.setup = tb_acpi_setup,
};

int tb_acpi_init(void)
{
	return register_acpi_bus_type(&tb_acpi_bus);
}

void tb_acpi_exit(void)
{
	unregister_acpi_bus_type(&tb_acpi_bus);
}