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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ACPI support
4 *
5 * Copyright (C) 2020, Intel Corporation
6 * Author: Mika Westerberg <[email protected]>
7 */
8
9#include <linux/acpi.h>
10#include <linux/pm_runtime.h>
11
12#include "tb.h"
13
14static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
15 void **ret)
16{
17 struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
18 struct fwnode_handle *fwnode;
19 struct tb_nhi *nhi = data;
20 struct pci_dev *pdev;
21 struct device *dev;
22
23 if (!adev)
24 return AE_OK;
25
26 fwnode = fwnode_find_reference(acpi_fwnode_handle(adev), "usb4-host-interface", 0);
27 if (IS_ERR(fwnode))
28 return AE_OK;
29
30 /* It needs to reference this NHI */
31 if (dev_fwnode(nhi->dev) != fwnode)
32 goto out_put;
33
34 /*
35 * Ignore USB3 ports here as USB core will set up device links between
36 * tunneled USB3 devices and NHI host during USB device creation.
37 * USB3 ports might not even have a physical device yet if xHCI driver
38 * isn't bound yet.
39 */
40 dev = acpi_get_first_physical_node(adev);
41 if (!dev || !dev_is_pci(dev))
42 goto out_put;
43
44 /* Check that this matches a PCIe root/downstream port. */
45 pdev = to_pci_dev(dev);
46 if (pci_is_pcie(pdev) &&
47 (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
48 pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM)) {
49 const struct device_link *link;
50
51 /*
52 * Make them both active first to make sure the NHI does
53 * not runtime suspend before the consumer. The
54 * pm_runtime_put() below then allows the consumer to
55 * runtime suspend again (which then allows NHI runtime
56 * suspend too now that the device link is established).
57 */
58 pm_runtime_get_sync(&pdev->dev);
59
60 link = device_link_add(&pdev->dev, nhi->dev,
61 DL_FLAG_AUTOREMOVE_SUPPLIER |
62 DL_FLAG_RPM_ACTIVE |
63 DL_FLAG_PM_RUNTIME);
64 if (link) {
65 dev_dbg(nhi->dev, "created link from %s\n",
66 dev_name(&pdev->dev));
67 *(bool *)ret = true;
68 } else {
69 dev_warn(nhi->dev, "device link creation from %s failed\n",
70 dev_name(&pdev->dev));
71 }
72
73 pm_runtime_put(&pdev->dev);
74 }
75
76out_put:
77 fwnode_handle_put(fwnode);
78 return AE_OK;
79}
80
81/**
82 * tb_acpi_add_links() - Add device links based on ACPI description
83 * @nhi: Pointer to NHI
84 *
85 * Goes over ACPI namespace finding tunneled ports that reference to
86 * @nhi ACPI node. For each reference a device link is added. The link
87 * is automatically removed by the driver core.
88 *
89 * Returns %true if at least one link was created, %false otherwise.
90 */
91bool tb_acpi_add_links(struct tb_nhi *nhi)
92{
93 acpi_status status;
94 bool ret = false;
95
96 if (!has_acpi_companion(nhi->dev))
97 return false;
98
99 /*
100 * Find all devices that have usb4-host-controller interface
101 * property that references to this NHI.
102 */
103 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 32,
104 tb_acpi_add_link, NULL, nhi, (void **)&ret);
105 if (ACPI_FAILURE(status)) {
106 dev_warn(nhi->dev, "failed to enumerate tunneled ports\n");
107 return false;
108 }
109
110 return ret;
111}
112
113/**
114 * tb_acpi_is_native() - Did the platform grant native TBT/USB4 control
115 *
116 * Return: %true if the platform granted OS native control over
117 * TBT/USB4, %false otherwise.
118 *
119 * When returned %true, software based connection manager can be used,
120 * otherwise there is firmware based connection manager running.
121 */
122bool tb_acpi_is_native(void)
123{
124 return osc_sb_native_usb4_support_confirmed &&
125 osc_sb_native_usb4_control;
126}
127
128/**
129 * tb_acpi_may_tunnel_usb3() - Is USB3 tunneling allowed by the platform
130 *
131 * Return: %true if software based connection manager is used and
132 * platform allows native USB 3.x tunneling, %false otherwise.
133 */
134bool tb_acpi_may_tunnel_usb3(void)
135{
136 if (tb_acpi_is_native())
137 return osc_sb_native_usb4_control & OSC_USB_USB3_TUNNELING;
138 return true;
139}
140
141/**
142 * tb_acpi_may_tunnel_dp() - Is DisplayPort tunneling allowed by the platform
143 *
144 * Return: %true if software based connection manager is used and
145 * platform allows native DP tunneling, %false otherwise.
146 */
147bool tb_acpi_may_tunnel_dp(void)
148{
149 if (tb_acpi_is_native())
150 return osc_sb_native_usb4_control & OSC_USB_DP_TUNNELING;
151 return true;
152}
153
154/**
155 * tb_acpi_may_tunnel_pcie() - Is PCIe tunneling allowed by the platform
156 *
157 * Return: %true if software based connection manager is used and
158 * platform allows native PCIe tunneling, %false otherwise.
159 */
160bool tb_acpi_may_tunnel_pcie(void)
161{
162 if (tb_acpi_is_native())
163 return osc_sb_native_usb4_control & OSC_USB_PCIE_TUNNELING;
164 return true;
165}
166
167/**
168 * tb_acpi_is_xdomain_allowed() - Are XDomain connections allowed
169 *
170 * Return: %true if software based connection manager is used and
171 * platform allows XDomain tunneling, %false otherwise.
172 */
173bool tb_acpi_is_xdomain_allowed(void)
174{
175 if (tb_acpi_is_native())
176 return osc_sb_native_usb4_control & OSC_USB_XDOMAIN;
177 return true;
178}
179
180/* UUID for retimer _DSM: e0053122-795b-4122-8a5e-57be1d26acb3 */
181static const guid_t retimer_dsm_guid =
182 GUID_INIT(0xe0053122, 0x795b, 0x4122,
183 0x8a, 0x5e, 0x57, 0xbe, 0x1d, 0x26, 0xac, 0xb3);
184
185#define RETIMER_DSM_QUERY_ONLINE_STATE 1
186#define RETIMER_DSM_SET_ONLINE_STATE 2
187
188static int tb_acpi_retimer_set_power(struct tb_port *port, bool power)
189{
190 struct usb4_port *usb4 = port->usb4;
191 union acpi_object argv4[2];
192 struct acpi_device *adev;
193 union acpi_object *obj;
194 int ret;
195
196 if (!usb4->can_offline)
197 return 0;
198
199 adev = ACPI_COMPANION(&usb4->dev);
200 if (WARN_ON(!adev))
201 return 0;
202
203 /* Check if we are already powered on (and in correct mode) */
204 obj = acpi_evaluate_dsm_typed(adev->handle, &retimer_dsm_guid, 1,
205 RETIMER_DSM_QUERY_ONLINE_STATE, NULL,
206 ACPI_TYPE_INTEGER);
207 if (!obj) {
208 tb_port_warn(port, "ACPI: query online _DSM failed\n");
209 return -EIO;
210 }
211
212 ret = obj->integer.value;
213 ACPI_FREE(obj);
214
215 if (power == ret)
216 return 0;
217
218 tb_port_dbg(port, "ACPI: calling _DSM to power %s retimers\n",
219 power ? "on" : "off");
220
221 argv4[0].type = ACPI_TYPE_PACKAGE;
222 argv4[0].package.count = 1;
223 argv4[0].package.elements = &argv4[1];
224 argv4[1].integer.type = ACPI_TYPE_INTEGER;
225 argv4[1].integer.value = power;
226
227 obj = acpi_evaluate_dsm_typed(adev->handle, &retimer_dsm_guid, 1,
228 RETIMER_DSM_SET_ONLINE_STATE, argv4,
229 ACPI_TYPE_INTEGER);
230 if (!obj) {
231 tb_port_warn(port,
232 "ACPI: set online state _DSM evaluation failed\n");
233 return -EIO;
234 }
235
236 ret = obj->integer.value;
237 ACPI_FREE(obj);
238
239 if (ret >= 0) {
240 if (power)
241 return ret == 1 ? 0 : -EBUSY;
242 return 0;
243 }
244
245 tb_port_warn(port, "ACPI: set online state _DSM failed with error %d\n", ret);
246 return -EIO;
247}
248
249/**
250 * tb_acpi_power_on_retimers() - Call platform to power on retimers
251 * @port: USB4 port
252 *
253 * Calls platform to turn on power to all retimers behind this USB4
254 * port. After this function returns successfully the caller can
255 * continue with the normal retimer flows (as specified in the USB4
256 * spec). Note if this returns %-EBUSY it means the type-C port is in
257 * non-USB4/TBT mode (there is non-USB4/TBT device connected).
258 *
259 * This should only be called if the USB4/TBT link is not up.
260 *
261 * Return: %0 on success, negative errno otherwise.
262 */
263int tb_acpi_power_on_retimers(struct tb_port *port)
264{
265 return tb_acpi_retimer_set_power(port, true);
266}
267
268/**
269 * tb_acpi_power_off_retimers() - Call platform to power off retimers
270 * @port: USB4 port
271 *
272 * This is the opposite of tb_acpi_power_on_retimers(). After returning
273 * successfully the normal operations with the @port can continue.
274 *
275 * Return: %0 on success, negative errno otherwise.
276 */
277int tb_acpi_power_off_retimers(struct tb_port *port)
278{
279 return tb_acpi_retimer_set_power(port, false);
280}
281
282static bool tb_acpi_bus_match(struct device *dev)
283{
284 return tb_is_switch(dev) || tb_is_usb4_port_device(dev);
285}
286
287static struct acpi_device *tb_acpi_switch_find_companion(struct tb_switch *sw)
288{
289 struct tb_switch *parent_sw = tb_switch_parent(sw);
290 struct acpi_device *adev = NULL;
291
292 /*
293 * Device routers exists under the downstream facing USB4 port
294 * of the parent router. Their _ADR is always 0.
295 */
296 if (parent_sw) {
297 struct tb_port *port = tb_switch_downstream_port(sw);
298 struct acpi_device *port_adev;
299
300 port_adev = acpi_find_child_by_adr(ACPI_COMPANION(&parent_sw->dev),
301 port->port);
302 if (port_adev)
303 adev = acpi_find_child_device(port_adev, 0, false);
304 } else {
305 struct tb_nhi *nhi = sw->tb->nhi;
306 struct acpi_device *parent_adev;
307
308 parent_adev = ACPI_COMPANION(nhi->dev);
309 if (parent_adev)
310 adev = acpi_find_child_device(parent_adev, 0, false);
311 }
312
313 return adev;
314}
315
316static struct acpi_device *tb_acpi_find_companion(struct device *dev)
317{
318 /*
319 * The Thunderbolt/USB4 hierarchy looks like following:
320 *
321 * Device (NHI)
322 * Device (HR) // Host router _ADR == 0
323 * Device (DFP0) // Downstream port _ADR == lane 0 adapter
324 * Device (DR) // Device router _ADR == 0
325 * Device (UFP) // Upstream port _ADR == lane 0 adapter
326 * Device (DFP1) // Downstream port _ADR == lane 0 adapter number
327 *
328 * At the moment we bind the host router to the corresponding
329 * Linux device.
330 */
331 if (tb_is_switch(dev))
332 return tb_acpi_switch_find_companion(tb_to_switch(dev));
333 if (tb_is_usb4_port_device(dev))
334 return acpi_find_child_by_adr(ACPI_COMPANION(dev->parent),
335 tb_to_usb4_port_device(dev)->port->port);
336 return NULL;
337}
338
339static void tb_acpi_setup(struct device *dev)
340{
341 struct acpi_device *adev = ACPI_COMPANION(dev);
342 struct usb4_port *usb4 = tb_to_usb4_port_device(dev);
343
344 if (!adev || !usb4)
345 return;
346
347 if (acpi_check_dsm(adev->handle, &retimer_dsm_guid, 1,
348 BIT(RETIMER_DSM_QUERY_ONLINE_STATE) |
349 BIT(RETIMER_DSM_SET_ONLINE_STATE)))
350 usb4->can_offline = true;
351}
352
353static struct acpi_bus_type tb_acpi_bus = {
354 .name = "thunderbolt",
355 .match = tb_acpi_bus_match,
356 .find_companion = tb_acpi_find_companion,
357 .setup = tb_acpi_setup,
358};
359
360int tb_acpi_init(void)
361{
362 return register_acpi_bus_type(&tb_acpi_bus);
363}
364
365void tb_acpi_exit(void)
366{
367 unregister_acpi_bus_type(&tb_acpi_bus);
368}