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5fd54ace | 1 | // SPDX-License-Identifier: GPL-2.0+ |
1da177e4 LT |
2 | /* |
3 | * epautoconf.c -- endpoint autoconfiguration for usb gadget drivers | |
4 | * | |
5 | * Copyright (C) 2004 David Brownell | |
1da177e4 LT |
6 | */ |
7 | ||
8 | #include <linux/kernel.h> | |
dc995fc2 | 9 | #include <linux/module.h> |
1da177e4 LT |
10 | #include <linux/types.h> |
11 | #include <linux/device.h> | |
12 | ||
13 | #include <linux/ctype.h> | |
14 | #include <linux/string.h> | |
15 | ||
5f848137 | 16 | #include <linux/usb/ch9.h> |
9454a57a | 17 | #include <linux/usb/gadget.h> |
1da177e4 | 18 | |
1da177e4 | 19 | /** |
a59d6b91 TB |
20 | * usb_ep_autoconfig_ss() - choose an endpoint matching the ep |
21 | * descriptor and ep companion descriptor | |
1da177e4 LT |
22 | * @gadget: The device to which the endpoint must belong. |
23 | * @desc: Endpoint descriptor, with endpoint direction and transfer mode | |
a59d6b91 TB |
24 | * initialized. For periodic transfers, the maximum packet |
25 | * size must also be initialized. This is modified on | |
26 | * success. | |
27 | * @ep_comp: Endpoint companion descriptor, with the required | |
28 | * number of streams. Will be modified when the chosen EP | |
29 | * supports a different number of streams. | |
1da177e4 | 30 | * |
a59d6b91 TB |
31 | * This routine replaces the usb_ep_autoconfig when needed |
32 | * superspeed enhancments. If such enhancemnets are required, | |
33 | * the FD should call usb_ep_autoconfig_ss directly and provide | |
34 | * the additional ep_comp parameter. | |
35 | * | |
36 | * By choosing an endpoint to use with the specified descriptor, | |
37 | * this routine simplifies writing gadget drivers that work with | |
38 | * multiple USB device controllers. The endpoint would be | |
39 | * passed later to usb_ep_enable(), along with some descriptor. | |
1da177e4 LT |
40 | * |
41 | * That second descriptor won't always be the same as the first one. | |
42 | * For example, isochronous endpoints can be autoconfigured for high | |
43 | * bandwidth, and then used in several lower bandwidth altsettings. | |
44 | * Also, high and full speed descriptors will be different. | |
45 | * | |
a59d6b91 TB |
46 | * Be sure to examine and test the results of autoconfiguration |
47 | * on your hardware. This code may not make the best choices | |
48 | * about how to use the USB controller, and it can't know all | |
49 | * the restrictions that may apply. Some combinations of driver | |
50 | * and hardware won't be able to autoconfigure. | |
1da177e4 | 51 | * |
f871cb9b | 52 | * On success, this returns an claimed usb_ep, and modifies the endpoint |
1da177e4 | 53 | * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value |
a59d6b91 TB |
54 | * is initialized as if the endpoint were used at full speed and |
55 | * the bmAttribute field in the ep companion descriptor is | |
56 | * updated with the assigned number of streams if it is | |
57 | * different from the original value. To prevent the endpoint | |
f871cb9b | 58 | * from being returned by a later autoconfig call, claims it by |
cc476b42 | 59 | * assigning ep->claimed to true. |
1da177e4 LT |
60 | * |
61 | * On failure, this returns a null endpoint descriptor. | |
62 | */ | |
a59d6b91 | 63 | struct usb_ep *usb_ep_autoconfig_ss( |
1da177e4 | 64 | struct usb_gadget *gadget, |
a59d6b91 TB |
65 | struct usb_endpoint_descriptor *desc, |
66 | struct usb_ss_ep_comp_descriptor *ep_comp | |
1da177e4 LT |
67 | ) |
68 | { | |
69 | struct usb_ep *ep; | |
70 | u8 type; | |
71 | ||
72 | type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; | |
73 | ||
596c154d RB |
74 | if (gadget->ops->match_ep) { |
75 | ep = gadget->ops->match_ep(gadget, desc, ep_comp); | |
76 | if (ep) | |
77 | goto found_ep; | |
78 | } | |
79 | ||
a353678d | 80 | /* Second, look at endpoints until an unclaimed one looks usable */ |
1da177e4 | 81 | list_for_each_entry (ep, &gadget->ep_list, ep_list) { |
4278c687 | 82 | if (usb_gadget_ep_match_desc(gadget, ep, desc, ep_comp)) |
609ca228 | 83 | goto found_ep; |
1da177e4 LT |
84 | } |
85 | ||
86 | /* Fail */ | |
87 | return NULL; | |
609ca228 | 88 | found_ep: |
5dbe135a RB |
89 | |
90 | /* | |
91 | * If the protocol driver hasn't yet decided on wMaxPacketSize | |
92 | * and wants to know the maximum possible, provide the info. | |
93 | */ | |
94 | if (desc->wMaxPacketSize == 0) | |
95 | desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket_limit); | |
96 | ||
97 | /* report address */ | |
98 | desc->bEndpointAddress &= USB_DIR_IN; | |
99 | if (isdigit(ep->name[2])) { | |
100 | u8 num = simple_strtoul(&ep->name[2], NULL, 10); | |
101 | desc->bEndpointAddress |= num; | |
102 | } else if (desc->bEndpointAddress & USB_DIR_IN) { | |
103 | if (++gadget->in_epnum > 15) | |
104 | return NULL; | |
105 | desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum; | |
106 | } else { | |
107 | if (++gadget->out_epnum > 15) | |
108 | return NULL; | |
109 | desc->bEndpointAddress |= gadget->out_epnum; | |
110 | } | |
111 | ||
112 | /* report (variable) full speed bulk maxpacket */ | |
113 | if ((type == USB_ENDPOINT_XFER_BULK) && !ep_comp) { | |
114 | int size = ep->maxpacket_limit; | |
115 | ||
116 | /* min() doesn't work on bitfields with gcc-3.5 */ | |
117 | if (size > 64) | |
118 | size = 64; | |
119 | desc->wMaxPacketSize = cpu_to_le16(size); | |
120 | } | |
121 | ||
122 | ep->address = desc->bEndpointAddress; | |
609ca228 SAS |
123 | ep->desc = NULL; |
124 | ep->comp_desc = NULL; | |
cc476b42 | 125 | ep->claimed = true; |
609ca228 | 126 | return ep; |
1da177e4 | 127 | } |
dc995fc2 | 128 | EXPORT_SYMBOL_GPL(usb_ep_autoconfig_ss); |
1da177e4 | 129 | |
a59d6b91 TB |
130 | /** |
131 | * usb_ep_autoconfig() - choose an endpoint matching the | |
132 | * descriptor | |
133 | * @gadget: The device to which the endpoint must belong. | |
134 | * @desc: Endpoint descriptor, with endpoint direction and transfer mode | |
135 | * initialized. For periodic transfers, the maximum packet | |
136 | * size must also be initialized. This is modified on success. | |
137 | * | |
138 | * By choosing an endpoint to use with the specified descriptor, this | |
139 | * routine simplifies writing gadget drivers that work with multiple | |
140 | * USB device controllers. The endpoint would be passed later to | |
141 | * usb_ep_enable(), along with some descriptor. | |
142 | * | |
143 | * That second descriptor won't always be the same as the first one. | |
144 | * For example, isochronous endpoints can be autoconfigured for high | |
145 | * bandwidth, and then used in several lower bandwidth altsettings. | |
146 | * Also, high and full speed descriptors will be different. | |
147 | * | |
148 | * Be sure to examine and test the results of autoconfiguration on your | |
149 | * hardware. This code may not make the best choices about how to use the | |
150 | * USB controller, and it can't know all the restrictions that may apply. | |
151 | * Some combinations of driver and hardware won't be able to autoconfigure. | |
152 | * | |
f871cb9b | 153 | * On success, this returns an claimed usb_ep, and modifies the endpoint |
a59d6b91 TB |
154 | * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value |
155 | * is initialized as if the endpoint were used at full speed. To prevent | |
f871cb9b | 156 | * the endpoint from being returned by a later autoconfig call, claims it |
cc476b42 | 157 | * by assigning ep->claimed to true. |
a59d6b91 TB |
158 | * |
159 | * On failure, this returns a null endpoint descriptor. | |
160 | */ | |
161 | struct usb_ep *usb_ep_autoconfig( | |
162 | struct usb_gadget *gadget, | |
163 | struct usb_endpoint_descriptor *desc | |
164 | ) | |
165 | { | |
166 | return usb_ep_autoconfig_ss(gadget, desc, NULL); | |
167 | } | |
dc995fc2 | 168 | EXPORT_SYMBOL_GPL(usb_ep_autoconfig); |
a59d6b91 | 169 | |
b67f628c RB |
170 | /** |
171 | * usb_ep_autoconfig_release - releases endpoint and set it to initial state | |
172 | * @ep: endpoint which should be released | |
173 | * | |
174 | * This function can be used during function bind for endpoints obtained | |
175 | * from usb_ep_autoconfig(). It unclaims endpoint claimed by | |
176 | * usb_ep_autoconfig() to make it available for other functions. Endpoint | |
177 | * which was released is no longer invalid and shouldn't be used in | |
178 | * context of function which released it. | |
179 | */ | |
180 | void usb_ep_autoconfig_release(struct usb_ep *ep) | |
181 | { | |
182 | ep->claimed = false; | |
183 | ep->driver_data = NULL; | |
184 | } | |
185 | EXPORT_SYMBOL_GPL(usb_ep_autoconfig_release); | |
186 | ||
1da177e4 LT |
187 | /** |
188 | * usb_ep_autoconfig_reset - reset endpoint autoconfig state | |
189 | * @gadget: device for which autoconfig state will be reset | |
190 | * | |
191 | * Use this for devices where one configuration may need to assign | |
192 | * endpoint resources very differently from the next one. It clears | |
cc476b42 | 193 | * state such as ep->claimed and the record of assigned endpoints |
1da177e4 LT |
194 | * used by usb_ep_autoconfig(). |
195 | */ | |
28824b18 | 196 | void usb_ep_autoconfig_reset (struct usb_gadget *gadget) |
1da177e4 LT |
197 | { |
198 | struct usb_ep *ep; | |
199 | ||
200 | list_for_each_entry (ep, &gadget->ep_list, ep_list) { | |
cc476b42 | 201 | ep->claimed = false; |
e4c1b1ba | 202 | ep->driver_data = NULL; |
1da177e4 | 203 | } |
e87bb711 SAS |
204 | gadget->in_epnum = 0; |
205 | gadget->out_epnum = 0; | |
1da177e4 | 206 | } |
dc995fc2 | 207 | EXPORT_SYMBOL_GPL(usb_ep_autoconfig_reset); |