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 11 #include "tb.h" 12 13 static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data, 14 void **return_value) 15 { 16 struct fwnode_reference_args args; 17 struct fwnode_handle *fwnode; 18 struct tb_nhi *nhi = data; 19 struct acpi_device *adev; 20 struct pci_dev *pdev; 21 struct device *dev; 22 int ret; 23 24 if (acpi_bus_get_device(handle, &adev)) 25 return AE_OK; 26 27 fwnode = acpi_fwnode_handle(adev); 28 ret = fwnode_property_get_reference_args(fwnode, "usb4-host-interface", 29 NULL, 0, 0, &args); 30 if (ret) 31 return AE_OK; 32 33 /* It needs to reference this NHI */ 34 if (nhi->pdev->dev.fwnode != args.fwnode) 35 goto out_put; 36 37 /* 38 * Try to find physical device walking upwards to the hierarcy. 39 * We need to do this because the xHCI driver might not yet be 40 * bound so the USB3 SuperSpeed ports are not yet created. 41 */ 42 dev = acpi_get_first_physical_node(adev); 43 while (!dev) { 44 adev = adev->parent; 45 if (!adev) 46 break; 47 dev = acpi_get_first_physical_node(adev); 48 } 49 50 if (!dev) 51 goto out_put; 52 53 /* 54 * Check that the device is PCIe. This is because USB3 55 * SuperSpeed ports have this property and they are not power 56 * managed with the xHCI and the SuperSpeed hub so we create the 57 * link from xHCI instead. 58 */ 59 while (!dev_is_pci(dev)) 60 dev = dev->parent; 61 62 if (!dev) 63 goto out_put; 64 65 /* 66 * Check that this actually matches the type of device we 67 * expect. It should either be xHCI or PCIe root/downstream 68 * port. 69 */ 70 pdev = to_pci_dev(dev); 71 if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI || 72 (pci_is_pcie(pdev) && 73 (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT || 74 pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM))) { 75 const struct device_link *link; 76 77 link = device_link_add(&pdev->dev, &nhi->pdev->dev, 78 DL_FLAG_AUTOREMOVE_SUPPLIER | 79 DL_FLAG_PM_RUNTIME); 80 if (link) { 81 dev_dbg(&nhi->pdev->dev, "created link from %s\n", 82 dev_name(&pdev->dev)); 83 } else { 84 dev_warn(&nhi->pdev->dev, "device link creation from %s failed\n", 85 dev_name(&pdev->dev)); 86 } 87 } 88 89 out_put: 90 fwnode_handle_put(args.fwnode); 91 return AE_OK; 92 } 93 94 /** 95 * tb_acpi_add_links() - Add device links based on ACPI description 96 * @nhi: Pointer to NHI 97 * 98 * Goes over ACPI namespace finding tunneled ports that reference to 99 * @nhi ACPI node. For each reference a device link is added. The link 100 * is automatically removed by the driver core. 101 */ 102 void tb_acpi_add_links(struct tb_nhi *nhi) 103 { 104 acpi_status status; 105 106 if (!has_acpi_companion(&nhi->pdev->dev)) 107 return; 108 109 /* 110 * Find all devices that have usb4-host-controller interface 111 * property that references to this NHI. 112 */ 113 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 32, 114 tb_acpi_add_link, NULL, nhi, NULL); 115 if (ACPI_FAILURE(status)) 116 dev_warn(&nhi->pdev->dev, "failed to enumerate tunneled ports\n"); 117 } 118