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 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 *
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/init.h>
24 #include <linux/types.h>
25 #include <linux/device.h>
26
27 #include <linux/ctype.h>
28 #include <linux/string.h>
29
30 #include <linux/usb/ch9.h>
31 #include <linux/usb/gadget.h>
32
33 #include "gadget_chips.h"
34
35
36 /* we must assign addresses for configurable endpoints (like net2280) */
37 static __initdata unsigned epnum;
38
39 // #define MANY_ENDPOINTS
40 #ifdef MANY_ENDPOINTS
41 /* more than 15 configurable endpoints */
42 static __initdata unsigned in_epnum;
43 #endif
44
45
46 /*
47 * This should work with endpoints from controller drivers sharing the
48 * same endpoint naming convention. By example:
49 *
50 * - ep1, ep2, ... address is fixed, not direction or type
51 * - ep1in, ep2out, ... address and direction are fixed, not type
52 * - ep1-bulk, ep2-bulk, ... address and type are fixed, not direction
53 * - ep1in-bulk, ep2out-iso, ... all three are fixed
54 * - ep-* ... no functionality restrictions
55 *
56 * Type suffixes are "-bulk", "-iso", or "-int". Numbers are decimal.
57 * Less common restrictions are implied by gadget_is_*().
58 *
59 * NOTE: each endpoint is unidirectional, as specified by its USB
60 * descriptor; and isn't specific to a configuration or altsetting.
61 */
62 static int __init
63 ep_matches (
64 struct usb_gadget *gadget,
65 struct usb_ep *ep,
66 struct usb_endpoint_descriptor *desc
67 )
68 {
69 u8 type;
70 const char *tmp;
71 u16 max;
72
73 /* endpoint already claimed? */
74 if (NULL != ep->driver_data)
75 return 0;
76
77 /* only support ep0 for portable CONTROL traffic */
78 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
79 if (USB_ENDPOINT_XFER_CONTROL == type)
80 return 0;
81
82 /* some other naming convention */
83 if ('e' != ep->name[0])
84 return 0;
85
86 /* type-restriction: "-iso", "-bulk", or "-int".
87 * direction-restriction: "in", "out".
88 */
89 if ('-' != ep->name[2]) {
90 tmp = strrchr (ep->name, '-');
91 if (tmp) {
92 switch (type) {
93 case USB_ENDPOINT_XFER_INT:
94 /* bulk endpoints handle interrupt transfers,
95 * except the toggle-quirky iso-synch kind
96 */
97 if ('s' == tmp[2]) // == "-iso"
98 return 0;
99 /* for now, avoid PXA "interrupt-in";
100 * it's documented as never using DATA1.
101 */
102 if (gadget_is_pxa (gadget)
103 && 'i' == tmp [1])
104 return 0;
105 break;
106 case USB_ENDPOINT_XFER_BULK:
107 if ('b' != tmp[1]) // != "-bulk"
108 return 0;
109 break;
110 case USB_ENDPOINT_XFER_ISOC:
111 if ('s' != tmp[2]) // != "-iso"
112 return 0;
113 }
114 } else {
115 tmp = ep->name + strlen (ep->name);
116 }
117
118 /* direction-restriction: "..in-..", "out-.." */
119 tmp--;
120 if (!isdigit (*tmp)) {
121 if (desc->bEndpointAddress & USB_DIR_IN) {
122 if ('n' != *tmp)
123 return 0;
124 } else {
125 if ('t' != *tmp)
126 return 0;
127 }
128 }
129 }
130
131 /* endpoint maxpacket size is an input parameter, except for bulk
132 * where it's an output parameter representing the full speed limit.
133 * the usb spec fixes high speed bulk maxpacket at 512 bytes.
134 */
135 max = 0x7ff & le16_to_cpu(desc->wMaxPacketSize);
136 switch (type) {
137 case USB_ENDPOINT_XFER_INT:
138 /* INT: limit 64 bytes full speed, 1024 high speed */
139 if (!gadget->is_dualspeed && max > 64)
140 return 0;
141 /* FALLTHROUGH */
142
143 case USB_ENDPOINT_XFER_ISOC:
144 /* ISO: limit 1023 bytes full speed, 1024 high speed */
145 if (ep->maxpacket < max)
146 return 0;
147 if (!gadget->is_dualspeed && max > 1023)
148 return 0;
149
150 /* BOTH: "high bandwidth" works only at high speed */
151 if ((desc->wMaxPacketSize & cpu_to_le16(3<<11))) {
152 if (!gadget->is_dualspeed)
153 return 0;
154 /* configure your hardware with enough buffering!! */
155 }
156 break;
157 }
158
159 /* MATCH!! */
160
161 /* report address */
162 desc->bEndpointAddress &= USB_DIR_IN;
163 if (isdigit (ep->name [2])) {
164 u8 num = simple_strtoul (&ep->name [2], NULL, 10);
165 desc->bEndpointAddress |= num;
166 #ifdef MANY_ENDPOINTS
167 } else if (desc->bEndpointAddress & USB_DIR_IN) {
168 if (++in_epnum > 15)
169 return 0;
170 desc->bEndpointAddress = USB_DIR_IN | in_epnum;
171 #endif
172 } else {
173 if (++epnum > 15)
174 return 0;
175 desc->bEndpointAddress |= epnum;
176 }
177
178 /* report (variable) full speed bulk maxpacket */
179 if (USB_ENDPOINT_XFER_BULK == type) {
180 int size = ep->maxpacket;
181
182 /* min() doesn't work on bitfields with gcc-3.5 */
183 if (size > 64)
184 size = 64;
185 desc->wMaxPacketSize = cpu_to_le16(size);
186 }
187 return 1;
188 }
189
190 static struct usb_ep * __init
191 find_ep (struct usb_gadget *gadget, const char *name)
192 {
193 struct usb_ep *ep;
194
195 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
196 if (0 == strcmp (ep->name, name))
197 return ep;
198 }
199 return NULL;
200 }
201
202 /**
203 * usb_ep_autoconfig - choose an endpoint matching the descriptor
204 * @gadget: The device to which the endpoint must belong.
205 * @desc: Endpoint descriptor, with endpoint direction and transfer mode
206 * initialized. For periodic transfers, the maximum packet
207 * size must also be initialized. This is modified on success.
208 *
209 * By choosing an endpoint to use with the specified descriptor, this
210 * routine simplifies writing gadget drivers that work with multiple
211 * USB device controllers. The endpoint would be passed later to
212 * usb_ep_enable(), along with some descriptor.
213 *
214 * That second descriptor won't always be the same as the first one.
215 * For example, isochronous endpoints can be autoconfigured for high
216 * bandwidth, and then used in several lower bandwidth altsettings.
217 * Also, high and full speed descriptors will be different.
218 *
219 * Be sure to examine and test the results of autoconfiguration on your
220 * hardware. This code may not make the best choices about how to use the
221 * USB controller, and it can't know all the restrictions that may apply.
222 * Some combinations of driver and hardware won't be able to autoconfigure.
223 *
224 * On success, this returns an un-claimed usb_ep, and modifies the endpoint
225 * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
226 * is initialized as if the endpoint were used at full speed. To prevent
227 * the endpoint from being returned by a later autoconfig call, claim it
228 * by assigning ep->driver_data to some non-null value.
229 *
230 * On failure, this returns a null endpoint descriptor.
231 */
232 struct usb_ep * __init usb_ep_autoconfig (
233 struct usb_gadget *gadget,
234 struct usb_endpoint_descriptor *desc
235 )
236 {
237 struct usb_ep *ep;
238 u8 type;
239
240 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
241
242 /* First, apply chip-specific "best usage" knowledge.
243 * This might make a good usb_gadget_ops hook ...
244 */
245 if (gadget_is_net2280 (gadget) && type == USB_ENDPOINT_XFER_INT) {
246 /* ep-e, ep-f are PIO with only 64 byte fifos */
247 ep = find_ep (gadget, "ep-e");
248 if (ep && ep_matches (gadget, ep, desc))
249 return ep;
250 ep = find_ep (gadget, "ep-f");
251 if (ep && ep_matches (gadget, ep, desc))
252 return ep;
253
254 } else if (gadget_is_goku (gadget)) {
255 if (USB_ENDPOINT_XFER_INT == type) {
256 /* single buffering is enough */
257 ep = find_ep (gadget, "ep3-bulk");
258 if (ep && ep_matches (gadget, ep, desc))
259 return ep;
260 } else if (USB_ENDPOINT_XFER_BULK == type
261 && (USB_DIR_IN & desc->bEndpointAddress)) {
262 /* DMA may be available */
263 ep = find_ep (gadget, "ep2-bulk");
264 if (ep && ep_matches (gadget, ep, desc))
265 return ep;
266 }
267
268 } else if (gadget_is_sh (gadget) && USB_ENDPOINT_XFER_INT == type) {
269 /* single buffering is enough; maybe 8 byte fifo is too */
270 ep = find_ep (gadget, "ep3in-bulk");
271 if (ep && ep_matches (gadget, ep, desc))
272 return ep;
273
274 } else if (gadget_is_mq11xx (gadget) && USB_ENDPOINT_XFER_INT == type) {
275 ep = find_ep (gadget, "ep1-bulk");
276 if (ep && ep_matches (gadget, ep, desc))
277 return ep;
278 }
279
280 /* Second, look at endpoints until an unclaimed one looks usable */
281 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
282 if (ep_matches (gadget, ep, desc))
283 return ep;
284 }
285
286 /* Fail */
287 return NULL;
288 }
289
290 /**
291 * usb_ep_autoconfig_reset - reset endpoint autoconfig state
292 * @gadget: device for which autoconfig state will be reset
293 *
294 * Use this for devices where one configuration may need to assign
295 * endpoint resources very differently from the next one. It clears
296 * state such as ep->driver_data and the record of assigned endpoints
297 * used by usb_ep_autoconfig().
298 */
299 void __init usb_ep_autoconfig_reset (struct usb_gadget *gadget)
300 {
301 struct usb_ep *ep;
302
303 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
304 ep->driver_data = NULL;
305 }
306 #ifdef MANY_ENDPOINTS
307 in_epnum = 0;
308 #endif
309 epnum = 0;
310 }
311
312
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