2 * epautoconf.c -- endpoint autoconfiguration for usb gadget drivers
4 * Copyright (C) 2004 David Brownell
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.
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.
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
22 #include <linux/kernel.h>
23 #include <linux/init.h>
24 #include <linux/types.h>
25 #include <linux/device.h>
27 #include <linux/ctype.h>
28 #include <linux/string.h>
30 #include <linux/usb/ch9.h>
31 #include <linux/usb/gadget.h>
33 #include "gadget_chips.h"
36 /* we must assign addresses for configurable endpoints (like net2280) */
37 static unsigned epnum;
39 // #define MANY_ENDPOINTS
41 /* more than 15 configurable endpoints */
42 static unsigned in_epnum;
47 * This should work with endpoints from controller drivers sharing the
48 * same endpoint naming convention. By example:
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
56 * Type suffixes are "-bulk", "-iso", or "-int". Numbers are decimal.
57 * Less common restrictions are implied by gadget_is_*().
59 * NOTE: each endpoint is unidirectional, as specified by its USB
60 * descriptor; and isn't specific to a configuration or altsetting.
64 struct usb_gadget *gadget,
66 struct usb_endpoint_descriptor *desc,
67 struct usb_ss_ep_comp_descriptor *ep_comp
74 int num_req_streams = 0;
76 /* endpoint already claimed? */
77 if (NULL != ep->driver_data)
80 /* only support ep0 for portable CONTROL traffic */
81 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
82 if (USB_ENDPOINT_XFER_CONTROL == type)
85 /* some other naming convention */
86 if ('e' != ep->name[0])
89 /* type-restriction: "-iso", "-bulk", or "-int".
90 * direction-restriction: "in", "out".
92 if ('-' != ep->name[2]) {
93 tmp = strrchr (ep->name, '-');
96 case USB_ENDPOINT_XFER_INT:
97 /* bulk endpoints handle interrupt transfers,
98 * except the toggle-quirky iso-synch kind
100 if ('s' == tmp[2]) // == "-iso"
102 /* for now, avoid PXA "interrupt-in";
103 * it's documented as never using DATA1.
105 if (gadget_is_pxa (gadget)
109 case USB_ENDPOINT_XFER_BULK:
110 if ('b' != tmp[1]) // != "-bulk"
113 case USB_ENDPOINT_XFER_ISOC:
114 if ('s' != tmp[2]) // != "-iso"
118 tmp = ep->name + strlen (ep->name);
121 /* direction-restriction: "..in-..", "out-.." */
123 if (!isdigit (*tmp)) {
124 if (desc->bEndpointAddress & USB_DIR_IN) {
135 * Get the number of required streams from the EP companion
136 * descriptor and see if the EP matches it
138 if (usb_endpoint_xfer_bulk(desc)) {
140 num_req_streams = ep_comp->bmAttributes & 0x1f;
141 if (num_req_streams > ep->max_streams)
143 /* Update the ep_comp descriptor if needed */
144 if (num_req_streams != ep->max_streams)
145 ep_comp->bmAttributes = ep->max_streams;
151 * If the protocol driver hasn't yet decided on wMaxPacketSize
152 * and wants to know the maximum possible, provide the info.
154 if (desc->wMaxPacketSize == 0)
155 desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket);
157 /* endpoint maxpacket size is an input parameter, except for bulk
158 * where it's an output parameter representing the full speed limit.
159 * the usb spec fixes high speed bulk maxpacket at 512 bytes.
161 max = 0x7ff & le16_to_cpu(desc->wMaxPacketSize);
163 case USB_ENDPOINT_XFER_INT:
164 /* INT: limit 64 bytes full speed, 1024 high/super speed */
165 if (!gadget->is_dualspeed && max > 64)
169 case USB_ENDPOINT_XFER_ISOC:
170 /* ISO: limit 1023 bytes full speed, 1024 high/super speed */
171 if (ep->maxpacket < max)
173 if (!gadget->is_dualspeed && max > 1023)
176 /* BOTH: "high bandwidth" works only at high speed */
177 if ((desc->wMaxPacketSize & cpu_to_le16(3<<11))) {
178 if (!gadget->is_dualspeed)
180 /* configure your hardware with enough buffering!! */
188 desc->bEndpointAddress &= USB_DIR_IN;
189 if (isdigit (ep->name [2])) {
190 u8 num = simple_strtoul (&ep->name [2], NULL, 10);
191 desc->bEndpointAddress |= num;
192 #ifdef MANY_ENDPOINTS
193 } else if (desc->bEndpointAddress & USB_DIR_IN) {
196 desc->bEndpointAddress = USB_DIR_IN | in_epnum;
201 desc->bEndpointAddress |= epnum;
204 /* report (variable) full speed bulk maxpacket */
205 if ((USB_ENDPOINT_XFER_BULK == type) && !ep_comp) {
206 int size = ep->maxpacket;
208 /* min() doesn't work on bitfields with gcc-3.5 */
211 desc->wMaxPacketSize = cpu_to_le16(size);
213 ep->address = desc->bEndpointAddress;
217 static struct usb_ep *
218 find_ep (struct usb_gadget *gadget, const char *name)
222 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
223 if (0 == strcmp (ep->name, name))
230 * usb_ep_autoconfig_ss() - choose an endpoint matching the ep
231 * descriptor and ep companion descriptor
232 * @gadget: The device to which the endpoint must belong.
233 * @desc: Endpoint descriptor, with endpoint direction and transfer mode
234 * initialized. For periodic transfers, the maximum packet
235 * size must also be initialized. This is modified on
237 * @ep_comp: Endpoint companion descriptor, with the required
238 * number of streams. Will be modified when the chosen EP
239 * supports a different number of streams.
241 * This routine replaces the usb_ep_autoconfig when needed
242 * superspeed enhancments. If such enhancemnets are required,
243 * the FD should call usb_ep_autoconfig_ss directly and provide
244 * the additional ep_comp parameter.
246 * By choosing an endpoint to use with the specified descriptor,
247 * this routine simplifies writing gadget drivers that work with
248 * multiple USB device controllers. The endpoint would be
249 * passed later to usb_ep_enable(), along with some descriptor.
251 * That second descriptor won't always be the same as the first one.
252 * For example, isochronous endpoints can be autoconfigured for high
253 * bandwidth, and then used in several lower bandwidth altsettings.
254 * Also, high and full speed descriptors will be different.
256 * Be sure to examine and test the results of autoconfiguration
257 * on your hardware. This code may not make the best choices
258 * about how to use the USB controller, and it can't know all
259 * the restrictions that may apply. Some combinations of driver
260 * and hardware won't be able to autoconfigure.
262 * On success, this returns an un-claimed usb_ep, and modifies the endpoint
263 * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
264 * is initialized as if the endpoint were used at full speed and
265 * the bmAttribute field in the ep companion descriptor is
266 * updated with the assigned number of streams if it is
267 * different from the original value. To prevent the endpoint
268 * from being returned by a later autoconfig call, claim it by
269 * assigning ep->driver_data to some non-null value.
271 * On failure, this returns a null endpoint descriptor.
273 struct usb_ep *usb_ep_autoconfig_ss(
274 struct usb_gadget *gadget,
275 struct usb_endpoint_descriptor *desc,
276 struct usb_ss_ep_comp_descriptor *ep_comp
282 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
284 /* First, apply chip-specific "best usage" knowledge.
285 * This might make a good usb_gadget_ops hook ...
287 if (gadget_is_net2280 (gadget) && type == USB_ENDPOINT_XFER_INT) {
288 /* ep-e, ep-f are PIO with only 64 byte fifos */
289 ep = find_ep (gadget, "ep-e");
290 if (ep && ep_matches(gadget, ep, desc, ep_comp))
292 ep = find_ep (gadget, "ep-f");
293 if (ep && ep_matches(gadget, ep, desc, ep_comp))
296 } else if (gadget_is_goku (gadget)) {
297 if (USB_ENDPOINT_XFER_INT == type) {
298 /* single buffering is enough */
299 ep = find_ep(gadget, "ep3-bulk");
300 if (ep && ep_matches(gadget, ep, desc, ep_comp))
302 } else if (USB_ENDPOINT_XFER_BULK == type
303 && (USB_DIR_IN & desc->bEndpointAddress)) {
304 /* DMA may be available */
305 ep = find_ep(gadget, "ep2-bulk");
306 if (ep && ep_matches(gadget, ep, desc,
311 #ifdef CONFIG_BLACKFIN
312 } else if (gadget_is_musbhdrc(gadget)) {
313 if ((USB_ENDPOINT_XFER_BULK == type) ||
314 (USB_ENDPOINT_XFER_ISOC == type)) {
315 if (USB_DIR_IN & desc->bEndpointAddress)
316 ep = find_ep (gadget, "ep5in");
318 ep = find_ep (gadget, "ep6out");
319 } else if (USB_ENDPOINT_XFER_INT == type) {
320 if (USB_DIR_IN & desc->bEndpointAddress)
321 ep = find_ep(gadget, "ep1in");
323 ep = find_ep(gadget, "ep2out");
326 if (ep && ep_matches(gadget, ep, desc, ep_comp))
331 /* Second, look at endpoints until an unclaimed one looks usable */
332 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
333 if (ep_matches(gadget, ep, desc, ep_comp))
342 * usb_ep_autoconfig() - choose an endpoint matching the
344 * @gadget: The device to which the endpoint must belong.
345 * @desc: Endpoint descriptor, with endpoint direction and transfer mode
346 * initialized. For periodic transfers, the maximum packet
347 * size must also be initialized. This is modified on success.
349 * By choosing an endpoint to use with the specified descriptor, this
350 * routine simplifies writing gadget drivers that work with multiple
351 * USB device controllers. The endpoint would be passed later to
352 * usb_ep_enable(), along with some descriptor.
354 * That second descriptor won't always be the same as the first one.
355 * For example, isochronous endpoints can be autoconfigured for high
356 * bandwidth, and then used in several lower bandwidth altsettings.
357 * Also, high and full speed descriptors will be different.
359 * Be sure to examine and test the results of autoconfiguration on your
360 * hardware. This code may not make the best choices about how to use the
361 * USB controller, and it can't know all the restrictions that may apply.
362 * Some combinations of driver and hardware won't be able to autoconfigure.
364 * On success, this returns an un-claimed usb_ep, and modifies the endpoint
365 * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
366 * is initialized as if the endpoint were used at full speed. To prevent
367 * the endpoint from being returned by a later autoconfig call, claim it
368 * by assigning ep->driver_data to some non-null value.
370 * On failure, this returns a null endpoint descriptor.
372 struct usb_ep *usb_ep_autoconfig(
373 struct usb_gadget *gadget,
374 struct usb_endpoint_descriptor *desc
377 return usb_ep_autoconfig_ss(gadget, desc, NULL);
382 * usb_ep_autoconfig_reset - reset endpoint autoconfig state
383 * @gadget: device for which autoconfig state will be reset
385 * Use this for devices where one configuration may need to assign
386 * endpoint resources very differently from the next one. It clears
387 * state such as ep->driver_data and the record of assigned endpoints
388 * used by usb_ep_autoconfig().
390 void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
394 list_for_each_entry (ep, &gadget->ep_list, ep_list) {
395 ep->driver_data = NULL;
397 #ifdef MANY_ENDPOINTS