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 "xhci.h"
  10
  11 #define USB_SW_DRV_NAME         "intel_xhci_usb_sw"
  12 #define USB_SW_RESOURCE_SIZE    0x400
  13
  14 static void xhci_intel_unregister_pdev(void *arg)
  15 {
  16         platform_device_unregister(arg);
  17 }
  18
  19 static int xhci_create_intel_xhci_sw_pdev(struct xhci_hcd *xhci, u32 cap_offset)
  20 {
  21         struct usb_hcd *hcd = xhci_to_hcd(xhci);
  22         struct device *dev = hcd->self.controller;
  23         struct platform_device *pdev;
  24         struct resource res = { 0, };
  25         int ret;
  26
  27         pdev = platform_device_alloc(USB_SW_DRV_NAME, PLATFORM_DEVID_NONE);
  28         if (!pdev) {
  29                 xhci_err(xhci, "couldn't allocate %s platform device\n",
  30                          USB_SW_DRV_NAME);
  31                 return -ENOMEM;
  32         }
  33
  34         res.start = hcd->rsrc_start + cap_offset;
  35         res.end   = res.start + USB_SW_RESOURCE_SIZE - 1;
  36         res.name  = USB_SW_DRV_NAME;
  37         res.flags = IORESOURCE_MEM;
  38
  39         ret = platform_device_add_resources(pdev, &res, 1);
  40         if (ret) {
  41                 dev_err(dev, "couldn't add resources to intel_xhci_usb_sw pdev\n");
  42                 platform_device_put(pdev);
  43                 return ret;
  44         }
  45
  46         pdev->dev.parent = dev;
  47
  48         ret = platform_device_add(pdev);
  49         if (ret) {
  50                 dev_err(dev, "couldn't register intel_xhci_usb_sw pdev\n");
  51                 platform_device_put(pdev);
  52                 return ret;
  53         }
  54
  55         ret = devm_add_action_or_reset(dev, xhci_intel_unregister_pdev, pdev);
  56         if (ret) {
  57                 dev_err(dev, "couldn't add unregister action for intel_xhci_usb_sw pdev\n");
  58                 return ret;
  59         }
  60
  61         return 0;
  62 }
  63
  64 int xhci_ext_cap_init(struct xhci_hcd *xhci)
  65 {
  66         void __iomem *base = &xhci->cap_regs->hc_capbase;
  67         u32 offset, val;
  68         int ret;
  69
  70         offset = xhci_find_next_ext_cap(base, 0, 0);
  71
  72         while (offset) {
  73                 val = readl(base + offset);
  74
  75                 switch (XHCI_EXT_CAPS_ID(val)) {
  76                 case XHCI_EXT_CAPS_VENDOR_INTEL:
  77                         if (xhci->quirks & XHCI_INTEL_USB_ROLE_SW) {
  78                                 ret = xhci_create_intel_xhci_sw_pdev(xhci,
  79                                                                      offset);
  80                                 if (ret)
  81                                         return ret;
  82                         }
  83                         break;
  84                 }
  85                 offset = xhci_find_next_ext_cap(base, offset, 0);
  86         }
  87
  88         return 0;
  89 }
  90 EXPORT_SYMBOL_GPL(xhci_ext_cap_init);