1 /*
2 * epautoconf.c -- endpoint autoconfiguration for usb gadget drivers
3 *
4 * Copyright (C) 2004 David Brownell
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/device.h>
17
18 #include <linux/ctype.h>
19 #include <linux/string.h>
20
21 #include <linux/usb/ch9.h>
22 #include <linux/usb/gadget.h>
23
24 #include "gadget_chips.h"
25
26 /*
27 * This should work with endpoints from controller drivers sharing the
28 * same endpoint naming convention. By example:
29 *
30 * - ep1, ep2, ... address is fixed, not direction or type
31 * - ep1in, ep2out, ... address and direction are fixed, not type
32 * - ep1-bulk, ep2-bulk, ... address and type are fixed, not direction
33 * - ep1in-bulk, ep2out-iso, ... all three are fixed
34 * - ep-* ... no functionality restrictions
35 *
36 * Type suffixes are "-bulk", "-iso", or "-int". Numbers are decimal.
37 * Less common restrictions are implied by gadget_is_*().
38 *
39 * NOTE: each endpoint is unidirectional, as specified by its USB
40 * descriptor; and isn't specific to a configuration or altsetting.
41 */
42 static int
ep_matches(struct usb_gadget * gadget,struct usb_ep * ep,struct usb_endpoint_descriptor * desc,struct usb_ss_ep_comp_descriptor * ep_comp)43 ep_matches (
44 struct usb_gadget *gadget,
45 struct usb_ep *ep,
46 struct usb_endpoint_descriptor *desc,
47 struct usb_ss_ep_comp_descriptor *ep_comp
48 )
49 {
50 u8 type;
51 const char *tmp;
52 u16 max;
53
54 int num_req_streams = 0;
55
56 /* endpoint already claimed? */
57 if (NULL != ep->driver_data)
58 return 0;
59
60 /* only support ep0 for portable CONTROL traffic */
61 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
62 if (USB_ENDPOINT_XFER_CONTROL == type)
63 return 0;
64
65 /* some other naming convention */
66 if ('e' != ep->name[0])
67 return 0;
68
69 /* type-restriction: "-iso", "-bulk", or "-int".
70 * direction-restriction: "in", "out".
71 */
72 if ('-' != ep->name[2]) {
73 tmp = strrchr (ep->name, '-');
74 if (tmp) {
75 switch (type) {
76 case USB_ENDPOINT_XFER_INT:
77 /* bulk endpoints handle interrupt transfers,
78 * except the toggle-quirky iso-synch kind
79 */
80 if ('s' == tmp[2]) // == "-iso"
81 return 0;
82 /* for now, avoid PXA "interrupt-in";
83 * it's documented as never using DATA1.
84 */
85 if (gadget_is_pxa (gadget)
86 && 'i' == tmp [1])
87 return 0;
88 break;
89 case USB_ENDPOINT_XFER_BULK:
90 if ('b' != tmp[1]) // != "-bulk"
91 return 0;
92 break;
93 case USB_ENDPOINT_XFER_ISOC:
94 if ('s' != tmp[2]) // != "-iso"
95 return 0;
96 }
97 } else {
98 tmp = ep->name + strlen (ep->name);
99 }
100
101 /* direction-restriction: "..in-..", "out-.." */
102 tmp--;
103 if (!isdigit (*tmp)) {
104 if (desc->bEndpointAddress & USB_DIR_IN) {
105 if ('n' != *tmp)
106 return 0;
107 } else {
108 if ('t' != *tmp)
109 return 0;
110 }
111 }
112 }
113
114 /*
115 * Get the number of required streams from the EP companion
116 * descriptor and see if the EP matches it
117 */
118 if (usb_endpoint_xfer_bulk(desc)) {
119 if (ep_comp && gadget->max_speed >= USB_SPEED_SUPER) {
120 num_req_streams = ep_comp->bmAttributes & 0x1f;
121 if (num_req_streams > ep->max_streams)
122 return 0;
123 }
124
125 }
126
127 /*
128 * If the protocol driver hasn't yet decided on wMaxPacketSize
129 * and wants to know the maximum possible, provide the info.
130 */
131 if (desc->wMaxPacketSize == 0)
132 desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket);
133
134 /* endpoint maxpacket size is an input parameter, except for bulk
135 * where it's an output parameter representing the full speed limit.
136 * the usb spec fixes high speed bulk maxpacket at 512 bytes.
137 */
138 max = 0x7ff & usb_endpoint_maxp(desc);
139 switch (type) {
140 case USB_ENDPOINT_XFER_INT:
141 /* INT: limit 64 bytes full speed, 1024 high/super speed */
142 if (!gadget_is_dualspeed(gadget) && max > 64)
143 return 0;
144 /* FALLTHROUGH */
145
146 case USB_ENDPOINT_XFER_ISOC:
147 /* ISO: limit 1023 bytes full speed, 1024 high/super speed */
148 if (ep->maxpacket < max)
149 return 0;
150 if (!gadget_is_dualspeed(gadget) && max > 1023)
151 return 0;
152
153 /* BOTH: "high bandwidth" works only at high speed */
154 if ((desc->wMaxPacketSize & cpu_to_le16(3<<11))) {
155 if (!gadget_is_dualspeed(gadget))
156 return 0;
157 /* configure your hardware with enough buffering!! */
158 }
159 break;
160 }
161
162 /* MATCH!! */
163
164 /* report address */
165 desc->bEndpointAddress &= USB_DIR_IN;
166 if (isdigit (ep->name [2])) {
167 u8 num = simple_strtoul (&ep->name [2], NULL, 10);
168 desc->bEndpointAddress |= num;
169 } else if (desc->bEndpointAddress & USB_DIR_IN) {
170 if (++gadget->in_epnum > 15)
171 return 0;
172 desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum;
173 } else {
174 if (++gadget->out_epnum > 15)
175 return 0;
176 desc->bEndpointAddress |= gadget->out_epnum;
177 }
178
179 /* report (variable) full speed bulk maxpacket */
180 if ((USB_ENDPOINT_XFER_BULK == type) && !ep_comp) {
181 int size = ep->maxpacket;
182
183 /* min() doesn't work on bitfields with gcc-3.5 */
184 if (size > 64)
185 size = 64;
186 desc->wMaxPacketSize = cpu_to_le16(size);
187 }
188 ep->address = desc->bEndpointAddress;
189 return 1;
190 }
191
192 static struct usb_ep *
find_ep(struct usb_gadget * gadget,const char * name)193 find_ep (struct usb_gadget *gadget, const char *name)
194 {
195 struct usb_ep *ep;
196
197 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
198 if (0 == strcmp (ep->name, name))
199 return ep;
200 }
201 return NULL;
202 }
203
204 /**
205 * usb_ep_autoconfig_ss() - choose an endpoint matching the ep
206 * descriptor and ep companion descriptor
207 * @gadget: The device to which the endpoint must belong.
208 * @desc: Endpoint descriptor, with endpoint direction and transfer mode
209 * initialized. For periodic transfers, the maximum packet
210 * size must also be initialized. This is modified on
211 * success.
212 * @ep_comp: Endpoint companion descriptor, with the required
213 * number of streams. Will be modified when the chosen EP
214 * supports a different number of streams.
215 *
216 * This routine replaces the usb_ep_autoconfig when needed
217 * superspeed enhancments. If such enhancemnets are required,
218 * the FD should call usb_ep_autoconfig_ss directly and provide
219 * the additional ep_comp parameter.
220 *
221 * By choosing an endpoint to use with the specified descriptor,
222 * this routine simplifies writing gadget drivers that work with
223 * multiple USB device controllers. The endpoint would be
224 * passed later to usb_ep_enable(), along with some descriptor.
225 *
226 * That second descriptor won't always be the same as the first one.
227 * For example, isochronous endpoints can be autoconfigured for high
228 * bandwidth, and then used in several lower bandwidth altsettings.
229 * Also, high and full speed descriptors will be different.
230 *
231 * Be sure to examine and test the results of autoconfiguration
232 * on your hardware. This code may not make the best choices
233 * about how to use the USB controller, and it can't know all
234 * the restrictions that may apply. Some combinations of driver
235 * and hardware won't be able to autoconfigure.
236 *
237 * On success, this returns an un-claimed usb_ep, and modifies the endpoint
238 * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
239 * is initialized as if the endpoint were used at full speed and
240 * the bmAttribute field in the ep companion descriptor is
241 * updated with the assigned number of streams if it is
242 * different from the original value. To prevent the endpoint
243 * from being returned by a later autoconfig call, claim it by
244 * assigning ep->driver_data to some non-null value.
245 *
246 * On failure, this returns a null endpoint descriptor.
247 */
usb_ep_autoconfig_ss(struct usb_gadget * gadget,struct usb_endpoint_descriptor * desc,struct usb_ss_ep_comp_descriptor * ep_comp)248 struct usb_ep *usb_ep_autoconfig_ss(
249 struct usb_gadget *gadget,
250 struct usb_endpoint_descriptor *desc,
251 struct usb_ss_ep_comp_descriptor *ep_comp
252 )
253 {
254 struct usb_ep *ep;
255 u8 type;
256
257 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
258
259 /* First, apply chip-specific "best usage" knowledge.
260 * This might make a good usb_gadget_ops hook ...
261 */
262 if (gadget_is_net2280 (gadget) && type == USB_ENDPOINT_XFER_INT) {
263 /* ep-e, ep-f are PIO with only 64 byte fifos */
264 ep = find_ep (gadget, "ep-e");
265 if (ep && ep_matches(gadget, ep, desc, ep_comp))
266 goto found_ep;
267 ep = find_ep (gadget, "ep-f");
268 if (ep && ep_matches(gadget, ep, desc, ep_comp))
269 goto found_ep;
270
271 } else if (gadget_is_goku (gadget)) {
272 if (USB_ENDPOINT_XFER_INT == type) {
273 /* single buffering is enough */
274 ep = find_ep(gadget, "ep3-bulk");
275 if (ep && ep_matches(gadget, ep, desc, ep_comp))
276 goto found_ep;
277 } else if (USB_ENDPOINT_XFER_BULK == type
278 && (USB_DIR_IN & desc->bEndpointAddress)) {
279 /* DMA may be available */
280 ep = find_ep(gadget, "ep2-bulk");
281 if (ep && ep_matches(gadget, ep, desc,
282 ep_comp))
283 goto found_ep;
284 }
285
286 #ifdef CONFIG_BLACKFIN
287 } else if (gadget_is_musbhdrc(gadget)) {
288 if ((USB_ENDPOINT_XFER_BULK == type) ||
289 (USB_ENDPOINT_XFER_ISOC == type)) {
290 if (USB_DIR_IN & desc->bEndpointAddress)
291 ep = find_ep (gadget, "ep5in");
292 else
293 ep = find_ep (gadget, "ep6out");
294 } else if (USB_ENDPOINT_XFER_INT == type) {
295 if (USB_DIR_IN & desc->bEndpointAddress)
296 ep = find_ep(gadget, "ep1in");
297 else
298 ep = find_ep(gadget, "ep2out");
299 } else
300 ep = NULL;
301 if (ep && ep_matches(gadget, ep, desc, ep_comp))
302 goto found_ep;
303 #endif
304 }
305
306 /* Second, look at endpoints until an unclaimed one looks usable */
307 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
308 if (ep_matches(gadget, ep, desc, ep_comp))
309 goto found_ep;
310 }
311
312 /* Fail */
313 return NULL;
314 found_ep:
315 ep->desc = NULL;
316 ep->comp_desc = NULL;
317 return ep;
318 }
319 EXPORT_SYMBOL_GPL(usb_ep_autoconfig_ss);
320
321 /**
322 * usb_ep_autoconfig() - choose an endpoint matching the
323 * descriptor
324 * @gadget: The device to which the endpoint must belong.
325 * @desc: Endpoint descriptor, with endpoint direction and transfer mode
326 * initialized. For periodic transfers, the maximum packet
327 * size must also be initialized. This is modified on success.
328 *
329 * By choosing an endpoint to use with the specified descriptor, this
330 * routine simplifies writing gadget drivers that work with multiple
331 * USB device controllers. The endpoint would be passed later to
332 * usb_ep_enable(), along with some descriptor.
333 *
334 * That second descriptor won't always be the same as the first one.
335 * For example, isochronous endpoints can be autoconfigured for high
336 * bandwidth, and then used in several lower bandwidth altsettings.
337 * Also, high and full speed descriptors will be different.
338 *
339 * Be sure to examine and test the results of autoconfiguration on your
340 * hardware. This code may not make the best choices about how to use the
341 * USB controller, and it can't know all the restrictions that may apply.
342 * Some combinations of driver and hardware won't be able to autoconfigure.
343 *
344 * On success, this returns an un-claimed usb_ep, and modifies the endpoint
345 * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
346 * is initialized as if the endpoint were used at full speed. To prevent
347 * the endpoint from being returned by a later autoconfig call, claim it
348 * by assigning ep->driver_data to some non-null value.
349 *
350 * On failure, this returns a null endpoint descriptor.
351 */
usb_ep_autoconfig(struct usb_gadget * gadget,struct usb_endpoint_descriptor * desc)352 struct usb_ep *usb_ep_autoconfig(
353 struct usb_gadget *gadget,
354 struct usb_endpoint_descriptor *desc
355 )
356 {
357 return usb_ep_autoconfig_ss(gadget, desc, NULL);
358 }
359 EXPORT_SYMBOL_GPL(usb_ep_autoconfig);
360
361 /**
362 * usb_ep_autoconfig_reset - reset endpoint autoconfig state
363 * @gadget: device for which autoconfig state will be reset
364 *
365 * Use this for devices where one configuration may need to assign
366 * endpoint resources very differently from the next one. It clears
367 * state such as ep->driver_data and the record of assigned endpoints
368 * used by usb_ep_autoconfig().
369 */
usb_ep_autoconfig_reset(struct usb_gadget * gadget)370 void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
371 {
372 struct usb_ep *ep;
373
374 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
375 ep->driver_data = NULL;
376 }
377 gadget->in_epnum = 0;
378 gadget->out_epnum = 0;
379 }
380 EXPORT_SYMBOL_GPL(usb_ep_autoconfig_reset);
381