drivers/usb/host/xhci-ext-caps.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * XHCI extended capability handling
   4  *
   5  * Copyright (c) 2017 Hans de Goede <hdegoede@redhat.com>
   6  */
   7
   8 #include <linux/platform_device.h>
   9 #include <linux/property.h>
  10 #include <linux/pci.h>
  11 #include "xhci.h"
  12
  13 #define USB_SW_DRV_NAME         "intel_xhci_usb_sw"
  14 #define USB_SW_RESOURCE_SIZE    0x400
  15
  16 #define PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI     0x22b5
  17
  18 static const struct property_entry role_switch_props[] = {
  19         PROPERTY_ENTRY_BOOL("sw_switch_disable"),
  20         {},
  21 };
  22
  23 static void xhci_intel_unregister_pdev(void *arg)
  24 {
  25         platform_device_unregister(arg);
  26 }
  27
  28 static int xhci_create_intel_xhci_sw_pdev(struct xhci_hcd *xhci, u32 cap_offset)
  29 {
  30         struct usb_hcd *hcd = xhci_to_hcd(xhci);
  31         struct device *dev = hcd->self.controller;
  32         struct platform_device *pdev;
  33         struct pci_dev *pci = to_pci_dev(dev);
  34         struct resource res = { 0, };
  35         int ret;
  36
  37         pdev = platform_device_alloc(USB_SW_DRV_NAME, PLATFORM_DEVID_NONE);
  38         if (!pdev) {
  39                 xhci_err(xhci, "couldn't allocate %s platform device\n",
  40                          USB_SW_DRV_NAME);
  41                 return -ENOMEM;
  42         }
  43
  44         res.start = hcd->rsrc_start + cap_offset;
  45         res.end   = res.start + USB_SW_RESOURCE_SIZE - 1;
  46         res.name  = USB_SW_DRV_NAME;
  47         res.flags = IORESOURCE_MEM;
  48
  49         ret = platform_device_add_resources(pdev, &res, 1);
  50         if (ret) {
  51                 dev_err(dev, "couldn't add resources to intel_xhci_usb_sw pdev\n");
  52                 platform_device_put(pdev);
  53                 return ret;
  54         }
  55
  56         if (pci->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI) {
  57                 ret = device_create_managed_software_node(&pdev->dev, role_switch_props,
  58                                                           NULL);
  59                 if (ret) {
  60                         dev_err(dev, "failed to register device properties\n");
  61                         platform_device_put(pdev);
  62                         return ret;
  63                 }
  64         }
  65
  66         pdev->dev.parent = dev;
  67
  68         ret = platform_device_add(pdev);
  69         if (ret) {
  70                 dev_err(dev, "couldn't register intel_xhci_usb_sw pdev\n");
  71                 platform_device_put(pdev);
  72                 return ret;
  73         }
  74
  75         ret = devm_add_action_or_reset(dev, xhci_intel_unregister_pdev, pdev);
  76         if (ret) {
  77                 dev_err(dev, "couldn't add unregister action for intel_xhci_usb_sw pdev\n");
  78                 return ret;
  79         }
  80
  81         return 0;
  82 }
  83
  84 int xhci_ext_cap_init(struct xhci_hcd *xhci)
  85 {
  86         void __iomem *base = &xhci->cap_regs->hc_capbase;
  87         u32 offset, val;
  88         int ret;
  89
  90         offset = xhci_find_next_ext_cap(base, 0, 0);
  91
  92         while (offset) {
  93                 val = readl(base + offset);
  94
  95                 switch (XHCI_EXT_CAPS_ID(val)) {
  96                 case XHCI_EXT_CAPS_VENDOR_INTEL:
  97                         if (xhci->quirks & XHCI_INTEL_USB_ROLE_SW) {
  98                                 ret = xhci_create_intel_xhci_sw_pdev(xhci,
  99                                                                      offset);
 100                                 if (ret)
 101                                         return ret;
 102                         }
 103                         break;
 104                 }
 105                 offset = xhci_find_next_ext_cap(base, offset, 0);
 106         }
 107
 108         return 0;
 109 }
 110 EXPORT_SYMBOL_GPL(xhci_ext_cap_init);