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 14 static 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 device *dev = NULL; 21 struct pci_dev *pdev; 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_bus_get_primary_device(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 76 out_put: 77 put_device(dev); 78 fwnode_handle_put(fwnode); 79 return AE_OK; 80 } 81 82 /** 83 * tb_acpi_add_links() - Add device links based on ACPI description 84 * @nhi: Pointer to NHI 85 * 86 * Goes over ACPI namespace finding tunneled ports that reference to 87 * @nhi ACPI node. For each reference a device link is added. The link 88 * is automatically removed by the driver core. 89 * 90 * Returns %true if at least one link was created, %false otherwise. 91 */ 92 bool tb_acpi_add_links(struct tb_nhi *nhi) 93 { 94 acpi_status status; 95 bool ret = false; 96 97 if (!has_acpi_companion(nhi->dev)) 98 return false; 99 100 /* 101 * Find all devices that have usb4-host-controller interface 102 * property that references to this NHI. 103 */ 104 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 32, 105 tb_acpi_add_link, NULL, nhi, (void **)&ret); 106 if (ACPI_FAILURE(status)) { 107 dev_warn(nhi->dev, "failed to enumerate tunneled ports\n"); 108 return false; 109 } 110 111 return ret; 112 } 113 114 /** 115 * tb_acpi_is_native() - Did the platform grant native TBT/USB4 control 116 * 117 * Return: %true if the platform granted OS native control over 118 * TBT/USB4, %false otherwise. 119 * 120 * When returned %true, software based connection manager can be used, 121 * otherwise there is firmware based connection manager running. 122 */ 123 bool tb_acpi_is_native(void) 124 { 125 return osc_sb_native_usb4_support_confirmed && 126 osc_sb_native_usb4_control; 127 } 128 129 /** 130 * tb_acpi_may_tunnel_usb3() - Is USB3 tunneling allowed by the platform 131 * 132 * Return: %true if software based connection manager is used and 133 * platform allows native USB 3.x tunneling, %false otherwise. 134 */ 135 bool tb_acpi_may_tunnel_usb3(void) 136 { 137 if (tb_acpi_is_native()) 138 return osc_sb_native_usb4_control & OSC_USB_USB3_TUNNELING; 139 return true; 140 } 141 142 /** 143 * tb_acpi_may_tunnel_dp() - Is DisplayPort tunneling allowed by the platform 144 * 145 * Return: %true if software based connection manager is used and 146 * platform allows native DP tunneling, %false otherwise. 147 */ 148 bool tb_acpi_may_tunnel_dp(void) 149 { 150 if (tb_acpi_is_native()) 151 return osc_sb_native_usb4_control & OSC_USB_DP_TUNNELING; 152 return true; 153 } 154 155 /** 156 * tb_acpi_may_tunnel_pcie() - Is PCIe tunneling allowed by the platform 157 * 158 * Return: %true if software based connection manager is used and 159 * platform allows native PCIe tunneling, %false otherwise. 160 */ 161 bool tb_acpi_may_tunnel_pcie(void) 162 { 163 if (tb_acpi_is_native()) 164 return osc_sb_native_usb4_control & OSC_USB_PCIE_TUNNELING; 165 return true; 166 } 167 168 /** 169 * tb_acpi_is_xdomain_allowed() - Are XDomain connections allowed 170 * 171 * Return: %true if software based connection manager is used and 172 * platform allows XDomain tunneling, %false otherwise. 173 */ 174 bool tb_acpi_is_xdomain_allowed(void) 175 { 176 if (tb_acpi_is_native()) 177 return osc_sb_native_usb4_control & OSC_USB_XDOMAIN; 178 return true; 179 } 180 181 /* UUID for retimer _DSM: e0053122-795b-4122-8a5e-57be1d26acb3 */ 182 static const guid_t retimer_dsm_guid = 183 GUID_INIT(0xe0053122, 0x795b, 0x4122, 184 0x8a, 0x5e, 0x57, 0xbe, 0x1d, 0x26, 0xac, 0xb3); 185 186 #define RETIMER_DSM_QUERY_ONLINE_STATE 1 187 #define RETIMER_DSM_SET_ONLINE_STATE 2 188 189 static int tb_acpi_retimer_set_power(struct tb_port *port, bool power) 190 { 191 struct usb4_port *usb4 = port->usb4; 192 union acpi_object argv4[2]; 193 struct acpi_device *adev; 194 union acpi_object *obj; 195 int ret; 196 197 if (!usb4->can_offline) 198 return 0; 199 200 adev = ACPI_COMPANION(&usb4->dev); 201 if (WARN_ON(!adev)) 202 return 0; 203 204 /* Check if we are already powered on (and in correct mode) */ 205 obj = acpi_evaluate_dsm_typed(adev->handle, &retimer_dsm_guid, 1, 206 RETIMER_DSM_QUERY_ONLINE_STATE, NULL, 207 ACPI_TYPE_INTEGER); 208 if (!obj) { 209 tb_port_warn(port, "ACPI: query online _DSM failed\n"); 210 return -EIO; 211 } 212 213 ret = obj->integer.value; 214 ACPI_FREE(obj); 215 216 if (power == ret) 217 return 0; 218 219 tb_port_dbg(port, "ACPI: calling _DSM to power %s retimers\n", 220 power ? "on" : "off"); 221 222 argv4[0].type = ACPI_TYPE_PACKAGE; 223 argv4[0].package.count = 1; 224 argv4[0].package.elements = &argv4[1]; 225 argv4[1].integer.type = ACPI_TYPE_INTEGER; 226 argv4[1].integer.value = power; 227 228 obj = acpi_evaluate_dsm_typed(adev->handle, &retimer_dsm_guid, 1, 229 RETIMER_DSM_SET_ONLINE_STATE, argv4, 230 ACPI_TYPE_INTEGER); 231 if (!obj) { 232 tb_port_warn(port, 233 "ACPI: set online state _DSM evaluation failed\n"); 234 return -EIO; 235 } 236 237 ret = obj->integer.value; 238 ACPI_FREE(obj); 239 240 if (ret >= 0) { 241 if (power) 242 return ret == 1 ? 0 : -EBUSY; 243 return 0; 244 } 245 246 tb_port_warn(port, "ACPI: set online state _DSM failed with error %d\n", ret); 247 return -EIO; 248 } 249 250 /** 251 * tb_acpi_power_on_retimers() - Call platform to power on retimers 252 * @port: USB4 port 253 * 254 * Calls platform to turn on power to all retimers behind this USB4 255 * port. After this function returns successfully the caller can 256 * continue with the normal retimer flows (as specified in the USB4 257 * spec). Note if this returns %-EBUSY it means the type-C port is in 258 * non-USB4/TBT mode (there is non-USB4/TBT device connected). 259 * 260 * This should only be called if the USB4/TBT link is not up. 261 * 262 * Return: %0 on success, negative errno otherwise. 263 */ 264 int tb_acpi_power_on_retimers(struct tb_port *port) 265 { 266 return tb_acpi_retimer_set_power(port, true); 267 } 268 269 /** 270 * tb_acpi_power_off_retimers() - Call platform to power off retimers 271 * @port: USB4 port 272 * 273 * This is the opposite of tb_acpi_power_on_retimers(). After returning 274 * successfully the normal operations with the @port can continue. 275 * 276 * Return: %0 on success, negative errno otherwise. 277 */ 278 int tb_acpi_power_off_retimers(struct tb_port *port) 279 { 280 return tb_acpi_retimer_set_power(port, false); 281 } 282 283 static bool tb_acpi_bus_match(struct device *dev) 284 { 285 return tb_is_switch(dev) || tb_is_usb4_port_device(dev); 286 } 287 288 static struct acpi_device *tb_acpi_switch_find_companion(struct tb_switch *sw) 289 { 290 struct tb_switch *parent_sw = tb_switch_parent(sw); 291 struct acpi_device *adev = NULL; 292 293 /* 294 * Device routers exists under the downstream facing USB4 port 295 * of the parent router. Their _ADR is always 0. 296 */ 297 if (parent_sw) { 298 struct tb_port *port = tb_switch_downstream_port(sw); 299 struct acpi_device *port_adev; 300 301 port_adev = acpi_find_child_by_adr(ACPI_COMPANION(&parent_sw->dev), 302 port->port); 303 if (port_adev) 304 adev = acpi_find_child_device(port_adev, 0, false); 305 } else { 306 struct tb_nhi *nhi = sw->tb->nhi; 307 struct acpi_device *parent_adev; 308 309 parent_adev = ACPI_COMPANION(nhi->dev); 310 if (parent_adev) 311 adev = acpi_find_child_device(parent_adev, 0, false); 312 } 313 314 return adev; 315 } 316 317 static struct acpi_device *tb_acpi_find_companion(struct device *dev) 318 { 319 /* 320 * The Thunderbolt/USB4 hierarchy looks like following: 321 * 322 * Device (NHI) 323 * Device (HR) // Host router _ADR == 0 324 * Device (DFP0) // Downstream port _ADR == lane 0 adapter 325 * Device (DR) // Device router _ADR == 0 326 * Device (UFP) // Upstream port _ADR == lane 0 adapter 327 * Device (DFP1) // Downstream port _ADR == lane 0 adapter number 328 * 329 * At the moment we bind the host router to the corresponding 330 * Linux device. 331 */ 332 if (tb_is_switch(dev)) 333 return tb_acpi_switch_find_companion(tb_to_switch(dev)); 334 if (tb_is_usb4_port_device(dev)) 335 return acpi_find_child_by_adr(ACPI_COMPANION(dev->parent), 336 tb_to_usb4_port_device(dev)->port->port); 337 return NULL; 338 } 339 340 static void tb_acpi_setup(struct device *dev) 341 { 342 struct acpi_device *adev = ACPI_COMPANION(dev); 343 struct usb4_port *usb4 = tb_to_usb4_port_device(dev); 344 345 if (!adev || !usb4) 346 return; 347 348 if (acpi_check_dsm(adev->handle, &retimer_dsm_guid, 1, 349 BIT(RETIMER_DSM_QUERY_ONLINE_STATE) | 350 BIT(RETIMER_DSM_SET_ONLINE_STATE))) 351 usb4->can_offline = true; 352 } 353 354 static struct acpi_bus_type tb_acpi_bus = { 355 .name = "thunderbolt", 356 .match = tb_acpi_bus_match, 357 .find_companion = tb_acpi_find_companion, 358 .setup = tb_acpi_setup, 359 }; 360 361 int tb_acpi_init(void) 362 { 363 return register_acpi_bus_type(&tb_acpi_bus); 364 } 365 366 void tb_acpi_exit(void) 367 { 368 unregister_acpi_bus_type(&tb_acpi_bus); 369 } 370