1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * ACPI support
  4 *
  5 * Copyright (C) 2020, Intel Corporation
  6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
  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 **return_value)
 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->pdev->dev) != fwnode)
 32		goto out_put;
 33
 34	/*
 35	 * Try to find physical device walking upwards to the hierarcy.
 36	 * We need to do this because the xHCI driver might not yet be
 37	 * bound so the USB3 SuperSpeed ports are not yet created.
 38	 */
 39	dev = acpi_get_first_physical_node(adev);
 40	while (!dev) {
 41		adev = acpi_dev_parent(adev);
 42		if (!adev)
 43			break;
 44		dev = acpi_get_first_physical_node(adev);
 45	}
 46
 47	if (!dev)
 48		goto out_put;
 49
 50	/*
 51	 * Check that the device is PCIe. This is because USB3
 52	 * SuperSpeed ports have this property and they are not power
 53	 * managed with the xHCI and the SuperSpeed hub so we create the
 54	 * link from xHCI instead.
 55	 */
 56	while (dev && !dev_is_pci(dev))
 57		dev = dev->parent;
 58
 59	if (!dev)
 60		goto out_put;
 61
 62	/*
 63	 * Check that this actually matches the type of device we
 64	 * expect. It should either be xHCI or PCIe root/downstream
 65	 * port.
 66	 */
 67	pdev = to_pci_dev(dev);
 68	if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI ||
 69	    (pci_is_pcie(pdev) &&
 70		(pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
 71		 pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM))) {
 72		const struct device_link *link;
 73
 74		/*
 75		 * Make them both active first to make sure the NHI does
 76		 * not runtime suspend before the consumer. The
 77		 * pm_runtime_put() below then allows the consumer to
 78		 * runtime suspend again (which then allows NHI runtime
 79		 * suspend too now that the device link is established).
 80		 */
 81		pm_runtime_get_sync(&pdev->dev);
 82
 83		link = device_link_add(&pdev->dev, &nhi->pdev->dev,
 84				       DL_FLAG_AUTOREMOVE_SUPPLIER |
 85				       DL_FLAG_RPM_ACTIVE |
 86				       DL_FLAG_PM_RUNTIME);
 87		if (link) {
 88			dev_dbg(&nhi->pdev->dev, "created link from %s\n",
 89				dev_name(&pdev->dev));
 90		} else {
 91			dev_warn(&nhi->pdev->dev, "device link creation from %s failed\n",
 92				 dev_name(&pdev->dev));
 93		}
 94
 95		pm_runtime_put(&pdev->dev);
 96	}
 97
 98out_put:
 99	fwnode_handle_put(fwnode);
100	return AE_OK;
101}
102
103/**
104 * tb_acpi_add_links() - Add device links based on ACPI description
105 * @nhi: Pointer to NHI
106 *
107 * Goes over ACPI namespace finding tunneled ports that reference to
108 * @nhi ACPI node. For each reference a device link is added. The link
109 * is automatically removed by the driver core.
110 */
111void tb_acpi_add_links(struct tb_nhi *nhi)
112{
113	acpi_status status;
114
115	if (!has_acpi_companion(&nhi->pdev->dev))
116		return;
117
118	/*
119	 * Find all devices that have usb4-host-controller interface
120	 * property that references to this NHI.
121	 */
122	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 32,
123				     tb_acpi_add_link, NULL, nhi, NULL);
124	if (ACPI_FAILURE(status))
125		dev_warn(&nhi->pdev->dev, "failed to enumerate tunneled ports\n");
126}
127
128/**
129 * tb_acpi_is_native() - Did the platform grant native TBT/USB4 control
130 *
131 * Returns %true if the platform granted OS native control over
132 * TBT/USB4. In this case software based connection manager can be used,
133 * otherwise there is firmware based connection manager running.
134 */
135bool tb_acpi_is_native(void)
136{
137	return osc_sb_native_usb4_support_confirmed &&
138	       osc_sb_native_usb4_control;
139}
140
141/**
142 * tb_acpi_may_tunnel_usb3() - Is USB3 tunneling allowed by the platform
143 *
144 * When software based connection manager is used, this function
145 * returns %true if platform allows native USB3 tunneling.
146 */
147bool tb_acpi_may_tunnel_usb3(void)
148{
149	if (tb_acpi_is_native())
150		return osc_sb_native_usb4_control & OSC_USB_USB3_TUNNELING;
151	return true;
152}
153
154/**
155 * tb_acpi_may_tunnel_dp() - Is DisplayPort tunneling allowed by the platform
156 *
157 * When software based connection manager is used, this function
158 * returns %true if platform allows native DP tunneling.
159 */
160bool tb_acpi_may_tunnel_dp(void)
161{
162	if (tb_acpi_is_native())
163		return osc_sb_native_usb4_control & OSC_USB_DP_TUNNELING;
164	return true;
165}
166
167/**
168 * tb_acpi_may_tunnel_pcie() - Is PCIe tunneling allowed by the platform
169 *
170 * When software based connection manager is used, this function
171 * returns %true if platform allows native PCIe tunneling.
172 */
173bool tb_acpi_may_tunnel_pcie(void)
174{
175	if (tb_acpi_is_native())
176		return osc_sb_native_usb4_control & OSC_USB_PCIE_TUNNELING;
177	return true;
178}
179
180/**
181 * tb_acpi_is_xdomain_allowed() - Are XDomain connections allowed
182 *
183 * When software based connection manager is used, this function
184 * returns %true if platform allows XDomain connections.
185 */
186bool tb_acpi_is_xdomain_allowed(void)
187{
188	if (tb_acpi_is_native())
189		return osc_sb_native_usb4_control & OSC_USB_XDOMAIN;
190	return true;
191}
192
193/* UUID for retimer _DSM: e0053122-795b-4122-8a5e-57be1d26acb3 */
194static const guid_t retimer_dsm_guid =
195	GUID_INIT(0xe0053122, 0x795b, 0x4122,
196		  0x8a, 0x5e, 0x57, 0xbe, 0x1d, 0x26, 0xac, 0xb3);
197
198#define RETIMER_DSM_QUERY_ONLINE_STATE	1
199#define RETIMER_DSM_SET_ONLINE_STATE	2
200
201static int tb_acpi_retimer_set_power(struct tb_port *port, bool power)
202{
203	struct usb4_port *usb4 = port->usb4;
204	union acpi_object argv4[2];
205	struct acpi_device *adev;
206	union acpi_object *obj;
207	int ret;
208
209	if (!usb4->can_offline)
210		return 0;
211
212	adev = ACPI_COMPANION(&usb4->dev);
213	if (WARN_ON(!adev))
214		return 0;
215
216	/* Check if we are already powered on (and in correct mode) */
217	obj = acpi_evaluate_dsm_typed(adev->handle, &retimer_dsm_guid, 1,
218				      RETIMER_DSM_QUERY_ONLINE_STATE, NULL,
219				      ACPI_TYPE_INTEGER);
220	if (!obj) {
221		tb_port_warn(port, "ACPI: query online _DSM failed\n");
222		return -EIO;
223	}
224
225	ret = obj->integer.value;
226	ACPI_FREE(obj);
227
228	if (power == ret)
229		return 0;
230
231	tb_port_dbg(port, "ACPI: calling _DSM to power %s retimers\n",
232		    power ? "on" : "off");
233
234	argv4[0].type = ACPI_TYPE_PACKAGE;
235	argv4[0].package.count = 1;
236	argv4[0].package.elements = &argv4[1];
237	argv4[1].integer.type = ACPI_TYPE_INTEGER;
238	argv4[1].integer.value = power;
239
240	obj = acpi_evaluate_dsm_typed(adev->handle, &retimer_dsm_guid, 1,
241				      RETIMER_DSM_SET_ONLINE_STATE, argv4,
242				      ACPI_TYPE_INTEGER);
243	if (!obj) {
244		tb_port_warn(port,
245			     "ACPI: set online state _DSM evaluation failed\n");
246		return -EIO;
247	}
248
249	ret = obj->integer.value;
250	ACPI_FREE(obj);
251
252	if (ret >= 0) {
253		if (power)
254			return ret == 1 ? 0 : -EBUSY;
255		return 0;
256	}
257
258	tb_port_warn(port, "ACPI: set online state _DSM failed with error %d\n", ret);
259	return -EIO;
260}
261
262/**
263 * tb_acpi_power_on_retimers() - Call platform to power on retimers
264 * @port: USB4 port
265 *
266 * Calls platform to turn on power to all retimers behind this USB4
267 * port. After this function returns successfully the caller can
268 * continue with the normal retimer flows (as specified in the USB4
269 * spec). Note if this returns %-EBUSY it means the type-C port is in
270 * non-USB4/TBT mode (there is non-USB4/TBT device connected).
271 *
272 * This should only be called if the USB4/TBT link is not up.
273 *
274 * Returns %0 on success.
275 */
276int tb_acpi_power_on_retimers(struct tb_port *port)
277{
278	return tb_acpi_retimer_set_power(port, true);
279}
280
281/**
282 * tb_acpi_power_off_retimers() - Call platform to power off retimers
283 * @port: USB4 port
284 *
285 * This is the opposite of tb_acpi_power_on_retimers(). After returning
286 * successfully the normal operations with the @port can continue.
287 *
288 * Returns %0 on success.
289 */
290int tb_acpi_power_off_retimers(struct tb_port *port)
291{
292	return tb_acpi_retimer_set_power(port, false);
293}
294
295static bool tb_acpi_bus_match(struct device *dev)
296{
297	return tb_is_switch(dev) || tb_is_usb4_port_device(dev);
298}
299
300static struct acpi_device *tb_acpi_switch_find_companion(struct tb_switch *sw)
301{
302	struct acpi_device *adev = NULL;
303	struct tb_switch *parent_sw;
304
305	/*
306	 * Device routers exists under the downstream facing USB4 port
307	 * of the parent router. Their _ADR is always 0.
308	 */
309	parent_sw = tb_switch_parent(sw);
310	if (parent_sw) {
311		struct tb_port *port = tb_port_at(tb_route(sw), parent_sw);
312		struct acpi_device *port_adev;
313
314		port_adev = acpi_find_child_by_adr(ACPI_COMPANION(&parent_sw->dev),
315						   port->port);
316		if (port_adev)
317			adev = acpi_find_child_device(port_adev, 0, false);
318	} else {
319		struct tb_nhi *nhi = sw->tb->nhi;
320		struct acpi_device *parent_adev;
321
322		parent_adev = ACPI_COMPANION(&nhi->pdev->dev);
323		if (parent_adev)
324			adev = acpi_find_child_device(parent_adev, 0, false);
325	}
326
327	return adev;
328}
329
330static struct acpi_device *tb_acpi_find_companion(struct device *dev)
331{
332	/*
333	 * The Thunderbolt/USB4 hierarchy looks like following:
334	 *
335	 * Device (NHI)
336	 *   Device (HR)		// Host router _ADR == 0
337	 *      Device (DFP0)		// Downstream port _ADR == lane 0 adapter
338	 *        Device (DR)		// Device router _ADR == 0
339	 *          Device (UFP)	// Upstream port _ADR == lane 0 adapter
340	 *      Device (DFP1)		// Downstream port _ADR == lane 0 adapter number
341	 *
342	 * At the moment we bind the host router to the corresponding
343	 * Linux device.
344	 */
345	if (tb_is_switch(dev))
346		return tb_acpi_switch_find_companion(tb_to_switch(dev));
347	else if (tb_is_usb4_port_device(dev))
348		return acpi_find_child_by_adr(ACPI_COMPANION(dev->parent),
349					      tb_to_usb4_port_device(dev)->port->port);
350	return NULL;
351}
352
353static void tb_acpi_setup(struct device *dev)
354{
355	struct acpi_device *adev = ACPI_COMPANION(dev);
356	struct usb4_port *usb4 = tb_to_usb4_port_device(dev);
357
358	if (!adev || !usb4)
359		return;
360
361	if (acpi_check_dsm(adev->handle, &retimer_dsm_guid, 1,
362			   BIT(RETIMER_DSM_QUERY_ONLINE_STATE) |
363			   BIT(RETIMER_DSM_SET_ONLINE_STATE)))
364		usb4->can_offline = true;
365}
366
367static struct acpi_bus_type tb_acpi_bus = {
368	.name = "thunderbolt",
369	.match = tb_acpi_bus_match,
370	.find_companion = tb_acpi_find_companion,
371	.setup = tb_acpi_setup,
372};
373
374int tb_acpi_init(void)
375{
376	return register_acpi_bus_type(&tb_acpi_bus);
377}
378
379void tb_acpi_exit(void)
380{
381	unregister_acpi_bus_type(&tb_acpi_bus);
382}