xref: /openbmc/linux/drivers/usb/host/xhci-ext-caps.c (revision a2818ee4)
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);
91