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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/init.h>
14#include <linux/types.h>
15#include <linux/device.h>
16
17#include <linux/ctype.h>
18#include <linux/string.h>
19
20#include <linux/usb/ch9.h>
21#include <linux/usb/gadget.h>
22
23#include "gadget_chips.h"
24
25
26/* we must assign addresses for configurable endpoints (like net2280) */
27static unsigned epnum;
28
29// #define MANY_ENDPOINTS
30#ifdef MANY_ENDPOINTS
31/* more than 15 configurable endpoints */
32static unsigned in_epnum;
33#endif
34
35
36/*
37 * This should work with endpoints from controller drivers sharing the
38 * same endpoint naming convention. By example:
39 *
40 * - ep1, ep2, ... address is fixed, not direction or type
41 * - ep1in, ep2out, ... address and direction are fixed, not type
42 * - ep1-bulk, ep2-bulk, ... address and type are fixed, not direction
43 * - ep1in-bulk, ep2out-iso, ... all three are fixed
44 * - ep-* ... no functionality restrictions
45 *
46 * Type suffixes are "-bulk", "-iso", or "-int". Numbers are decimal.
47 * Less common restrictions are implied by gadget_is_*().
48 *
49 * NOTE: each endpoint is unidirectional, as specified by its USB
50 * descriptor; and isn't specific to a configuration or altsetting.
51 */
52static int
53ep_matches (
54 struct usb_gadget *gadget,
55 struct usb_ep *ep,
56 struct usb_endpoint_descriptor *desc,
57 struct usb_ss_ep_comp_descriptor *ep_comp
58)
59{
60 u8 type;
61 const char *tmp;
62 u16 max;
63
64 int num_req_streams = 0;
65
66 /* endpoint already claimed? */
67 if (NULL != ep->driver_data)
68 return 0;
69
70 /* only support ep0 for portable CONTROL traffic */
71 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
72 if (USB_ENDPOINT_XFER_CONTROL == type)
73 return 0;
74
75 /* some other naming convention */
76 if ('e' != ep->name[0])
77 return 0;
78
79 /* type-restriction: "-iso", "-bulk", or "-int".
80 * direction-restriction: "in", "out".
81 */
82 if ('-' != ep->name[2]) {
83 tmp = strrchr (ep->name, '-');
84 if (tmp) {
85 switch (type) {
86 case USB_ENDPOINT_XFER_INT:
87 /* bulk endpoints handle interrupt transfers,
88 * except the toggle-quirky iso-synch kind
89 */
90 if ('s' == tmp[2]) // == "-iso"
91 return 0;
92 /* for now, avoid PXA "interrupt-in";
93 * it's documented as never using DATA1.
94 */
95 if (gadget_is_pxa (gadget)
96 && 'i' == tmp [1])
97 return 0;
98 break;
99 case USB_ENDPOINT_XFER_BULK:
100 if ('b' != tmp[1]) // != "-bulk"
101 return 0;
102 break;
103 case USB_ENDPOINT_XFER_ISOC:
104 if ('s' != tmp[2]) // != "-iso"
105 return 0;
106 }
107 } else {
108 tmp = ep->name + strlen (ep->name);
109 }
110
111 /* direction-restriction: "..in-..", "out-.." */
112 tmp--;
113 if (!isdigit (*tmp)) {
114 if (desc->bEndpointAddress & USB_DIR_IN) {
115 if ('n' != *tmp)
116 return 0;
117 } else {
118 if ('t' != *tmp)
119 return 0;
120 }
121 }
122 }
123
124 /*
125 * Get the number of required streams from the EP companion
126 * descriptor and see if the EP matches it
127 */
128 if (usb_endpoint_xfer_bulk(desc)) {
129 if (ep_comp && gadget->max_speed >= USB_SPEED_SUPER) {
130 num_req_streams = ep_comp->bmAttributes & 0x1f;
131 if (num_req_streams > ep->max_streams)
132 return 0;
133 }
134
135 }
136
137 /*
138 * If the protocol driver hasn't yet decided on wMaxPacketSize
139 * and wants to know the maximum possible, provide the info.
140 */
141 if (desc->wMaxPacketSize == 0)
142 desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket);
143
144 /* endpoint maxpacket size is an input parameter, except for bulk
145 * where it's an output parameter representing the full speed limit.
146 * the usb spec fixes high speed bulk maxpacket at 512 bytes.
147 */
148 max = 0x7ff & usb_endpoint_maxp(desc);
149 switch (type) {
150 case USB_ENDPOINT_XFER_INT:
151 /* INT: limit 64 bytes full speed, 1024 high/super speed */
152 if (!gadget_is_dualspeed(gadget) && max > 64)
153 return 0;
154 /* FALLTHROUGH */
155
156 case USB_ENDPOINT_XFER_ISOC:
157 /* ISO: limit 1023 bytes full speed, 1024 high/super speed */
158 if (ep->maxpacket < max)
159 return 0;
160 if (!gadget_is_dualspeed(gadget) && max > 1023)
161 return 0;
162
163 /* BOTH: "high bandwidth" works only at high speed */
164 if ((desc->wMaxPacketSize & cpu_to_le16(3<<11))) {
165 if (!gadget_is_dualspeed(gadget))
166 return 0;
167 /* configure your hardware with enough buffering!! */
168 }
169 break;
170 }
171
172 /* MATCH!! */
173
174 /* report address */
175 desc->bEndpointAddress &= USB_DIR_IN;
176 if (isdigit (ep->name [2])) {
177 u8 num = simple_strtoul (&ep->name [2], NULL, 10);
178 desc->bEndpointAddress |= num;
179#ifdef MANY_ENDPOINTS
180 } else if (desc->bEndpointAddress & USB_DIR_IN) {
181 if (++in_epnum > 15)
182 return 0;
183 desc->bEndpointAddress = USB_DIR_IN | in_epnum;
184#endif
185 } else {
186 if (++epnum > 15)
187 return 0;
188 desc->bEndpointAddress |= epnum;
189 }
190
191 /* report (variable) full speed bulk maxpacket */
192 if ((USB_ENDPOINT_XFER_BULK == type) && !ep_comp) {
193 int size = ep->maxpacket;
194
195 /* min() doesn't work on bitfields with gcc-3.5 */
196 if (size > 64)
197 size = 64;
198 desc->wMaxPacketSize = cpu_to_le16(size);
199 }
200 ep->address = desc->bEndpointAddress;
201 return 1;
202}
203
204static struct usb_ep *
205find_ep (struct usb_gadget *gadget, const char *name)
206{
207 struct usb_ep *ep;
208
209 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
210 if (0 == strcmp (ep->name, name))
211 return ep;
212 }
213 return NULL;
214}
215
216/**
217 * usb_ep_autoconfig_ss() - choose an endpoint matching the ep
218 * descriptor and ep companion descriptor
219 * @gadget: The device to which the endpoint must belong.
220 * @desc: Endpoint descriptor, with endpoint direction and transfer mode
221 * initialized. For periodic transfers, the maximum packet
222 * size must also be initialized. This is modified on
223 * success.
224 * @ep_comp: Endpoint companion descriptor, with the required
225 * number of streams. Will be modified when the chosen EP
226 * supports a different number of streams.
227 *
228 * This routine replaces the usb_ep_autoconfig when needed
229 * superspeed enhancments. If such enhancemnets are required,
230 * the FD should call usb_ep_autoconfig_ss directly and provide
231 * the additional ep_comp parameter.
232 *
233 * By choosing an endpoint to use with the specified descriptor,
234 * this routine simplifies writing gadget drivers that work with
235 * multiple USB device controllers. The endpoint would be
236 * passed later to usb_ep_enable(), along with some descriptor.
237 *
238 * That second descriptor won't always be the same as the first one.
239 * For example, isochronous endpoints can be autoconfigured for high
240 * bandwidth, and then used in several lower bandwidth altsettings.
241 * Also, high and full speed descriptors will be different.
242 *
243 * Be sure to examine and test the results of autoconfiguration
244 * on your hardware. This code may not make the best choices
245 * about how to use the USB controller, and it can't know all
246 * the restrictions that may apply. Some combinations of driver
247 * and hardware won't be able to autoconfigure.
248 *
249 * On success, this returns an un-claimed usb_ep, and modifies the endpoint
250 * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
251 * is initialized as if the endpoint were used at full speed and
252 * the bmAttribute field in the ep companion descriptor is
253 * updated with the assigned number of streams if it is
254 * different from the original value. To prevent the endpoint
255 * from being returned by a later autoconfig call, claim it by
256 * assigning ep->driver_data to some non-null value.
257 *
258 * On failure, this returns a null endpoint descriptor.
259 */
260struct usb_ep *usb_ep_autoconfig_ss(
261 struct usb_gadget *gadget,
262 struct usb_endpoint_descriptor *desc,
263 struct usb_ss_ep_comp_descriptor *ep_comp
264)
265{
266 struct usb_ep *ep;
267 u8 type;
268
269 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
270
271 /* First, apply chip-specific "best usage" knowledge.
272 * This might make a good usb_gadget_ops hook ...
273 */
274 if (gadget_is_net2280 (gadget) && type == USB_ENDPOINT_XFER_INT) {
275 /* ep-e, ep-f are PIO with only 64 byte fifos */
276 ep = find_ep (gadget, "ep-e");
277 if (ep && ep_matches(gadget, ep, desc, ep_comp))
278 goto found_ep;
279 ep = find_ep (gadget, "ep-f");
280 if (ep && ep_matches(gadget, ep, desc, ep_comp))
281 goto found_ep;
282
283 } else if (gadget_is_goku (gadget)) {
284 if (USB_ENDPOINT_XFER_INT == type) {
285 /* single buffering is enough */
286 ep = find_ep(gadget, "ep3-bulk");
287 if (ep && ep_matches(gadget, ep, desc, ep_comp))
288 goto found_ep;
289 } else if (USB_ENDPOINT_XFER_BULK == type
290 && (USB_DIR_IN & desc->bEndpointAddress)) {
291 /* DMA may be available */
292 ep = find_ep(gadget, "ep2-bulk");
293 if (ep && ep_matches(gadget, ep, desc,
294 ep_comp))
295 goto found_ep;
296 }
297
298#ifdef CONFIG_BLACKFIN
299 } else if (gadget_is_musbhdrc(gadget)) {
300 if ((USB_ENDPOINT_XFER_BULK == type) ||
301 (USB_ENDPOINT_XFER_ISOC == type)) {
302 if (USB_DIR_IN & desc->bEndpointAddress)
303 ep = find_ep (gadget, "ep5in");
304 else
305 ep = find_ep (gadget, "ep6out");
306 } else if (USB_ENDPOINT_XFER_INT == type) {
307 if (USB_DIR_IN & desc->bEndpointAddress)
308 ep = find_ep(gadget, "ep1in");
309 else
310 ep = find_ep(gadget, "ep2out");
311 } else
312 ep = NULL;
313 if (ep && ep_matches(gadget, ep, desc, ep_comp))
314 goto found_ep;
315#endif
316 }
317
318 /* Second, look at endpoints until an unclaimed one looks usable */
319 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
320 if (ep_matches(gadget, ep, desc, ep_comp))
321 goto found_ep;
322 }
323
324 /* Fail */
325 return NULL;
326found_ep:
327 ep->desc = NULL;
328 ep->comp_desc = NULL;
329 return ep;
330}
331
332/**
333 * usb_ep_autoconfig() - choose an endpoint matching the
334 * descriptor
335 * @gadget: The device to which the endpoint must belong.
336 * @desc: Endpoint descriptor, with endpoint direction and transfer mode
337 * initialized. For periodic transfers, the maximum packet
338 * size must also be initialized. This is modified on success.
339 *
340 * By choosing an endpoint to use with the specified descriptor, this
341 * routine simplifies writing gadget drivers that work with multiple
342 * USB device controllers. The endpoint would be passed later to
343 * usb_ep_enable(), along with some descriptor.
344 *
345 * That second descriptor won't always be the same as the first one.
346 * For example, isochronous endpoints can be autoconfigured for high
347 * bandwidth, and then used in several lower bandwidth altsettings.
348 * Also, high and full speed descriptors will be different.
349 *
350 * Be sure to examine and test the results of autoconfiguration on your
351 * hardware. This code may not make the best choices about how to use the
352 * USB controller, and it can't know all the restrictions that may apply.
353 * Some combinations of driver and hardware won't be able to autoconfigure.
354 *
355 * On success, this returns an un-claimed usb_ep, and modifies the endpoint
356 * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
357 * is initialized as if the endpoint were used at full speed. To prevent
358 * the endpoint from being returned by a later autoconfig call, claim it
359 * by assigning ep->driver_data to some non-null value.
360 *
361 * On failure, this returns a null endpoint descriptor.
362 */
363struct usb_ep *usb_ep_autoconfig(
364 struct usb_gadget *gadget,
365 struct usb_endpoint_descriptor *desc
366)
367{
368 return usb_ep_autoconfig_ss(gadget, desc, NULL);
369}
370
371
372/**
373 * usb_ep_autoconfig_reset - reset endpoint autoconfig state
374 * @gadget: device for which autoconfig state will be reset
375 *
376 * Use this for devices where one configuration may need to assign
377 * endpoint resources very differently from the next one. It clears
378 * state such as ep->driver_data and the record of assigned endpoints
379 * used by usb_ep_autoconfig().
380 */
381void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
382{
383 struct usb_ep *ep;
384
385 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
386 ep->driver_data = NULL;
387 }
388#ifdef MANY_ENDPOINTS
389 in_epnum = 0;
390#endif
391 epnum = 0;
392}
393