epautoconf.c revision a4c39c41bf3592684e36fa0dbbd4ab1a31f969b9
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) */ 37static __initdata unsigned epnum; 38 39// #define MANY_ENDPOINTS 40#ifdef MANY_ENDPOINTS 41/* more than 15 configurable endpoints */ 42static __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 */ 62static int __init 63ep_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 & __constant_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_strtol (&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 190static struct usb_ep * __init 191find_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 */ 232struct 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 */ 299void __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