xref: /openbmc/linux/drivers/usb/host/xhci-ext-caps.c (revision 3dc4b6fb)
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 = platform_device_add_properties(pdev, role_switch_props);
58 		if (ret) {
59 			dev_err(dev, "failed to register device properties\n");
60 			return ret;
61 		}
62 	}
63 
64 	pdev->dev.parent = dev;
65 
66 	ret = platform_device_add(pdev);
67 	if (ret) {
68 		dev_err(dev, "couldn't register intel_xhci_usb_sw pdev\n");
69 		platform_device_put(pdev);
70 		return ret;
71 	}
72 
73 	ret = devm_add_action_or_reset(dev, xhci_intel_unregister_pdev, pdev);
74 	if (ret) {
75 		dev_err(dev, "couldn't add unregister action for intel_xhci_usb_sw pdev\n");
76 		return ret;
77 	}
78 
79 	return 0;
80 }
81 
82 int xhci_ext_cap_init(struct xhci_hcd *xhci)
83 {
84 	void __iomem *base = &xhci->cap_regs->hc_capbase;
85 	u32 offset, val;
86 	int ret;
87 
88 	offset = xhci_find_next_ext_cap(base, 0, 0);
89 
90 	while (offset) {
91 		val = readl(base + offset);
92 
93 		switch (XHCI_EXT_CAPS_ID(val)) {
94 		case XHCI_EXT_CAPS_VENDOR_INTEL:
95 			if (xhci->quirks & XHCI_INTEL_USB_ROLE_SW) {
96 				ret = xhci_create_intel_xhci_sw_pdev(xhci,
97 								     offset);
98 				if (ret)
99 					return ret;
100 			}
101 			break;
102 		}
103 		offset = xhci_find_next_ext_cap(base, offset, 0);
104 	}
105 
106 	return 0;
107 }
108 EXPORT_SYMBOL_GPL(xhci_ext_cap_init);
109