drivers/thunderbolt/acpi.c

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