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 unsigned epnum; 38 39 // #define MANY_ENDPOINTS 40 #ifdef MANY_ENDPOINTS 41 /* more than 15 configurable endpoints */ 42 static 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 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 /* 132 * If the protocol driver hasn't yet decided on wMaxPacketSize 133 * and wants to know the maximum possible, provide the info. 134 */ 135 if (desc->wMaxPacketSize == 0) 136 desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket); 137 138 /* endpoint maxpacket size is an input parameter, except for bulk 139 * where it's an output parameter representing the full speed limit. 140 * the usb spec fixes high speed bulk maxpacket at 512 bytes. 141 */ 142 max = 0x7ff & le16_to_cpu(desc->wMaxPacketSize); 143 switch (type) { 144 case USB_ENDPOINT_XFER_INT: 145 /* INT: limit 64 bytes full speed, 1024 high speed */ 146 if (!gadget->is_dualspeed && max > 64) 147 return 0; 148 /* FALLTHROUGH */ 149 150 case USB_ENDPOINT_XFER_ISOC: 151 /* ISO: limit 1023 bytes full speed, 1024 high speed */ 152 if (ep->maxpacket < max) 153 return 0; 154 if (!gadget->is_dualspeed && max > 1023) 155 return 0; 156 157 /* BOTH: "high bandwidth" works only at high speed */ 158 if ((desc->wMaxPacketSize & cpu_to_le16(3<<11))) { 159 if (!gadget->is_dualspeed) 160 return 0; 161 /* configure your hardware with enough buffering!! */ 162 } 163 break; 164 } 165 166 /* MATCH!! */ 167 168 /* report address */ 169 desc->bEndpointAddress &= USB_DIR_IN; 170 if (isdigit (ep->name [2])) { 171 u8 num = simple_strtoul (&ep->name [2], NULL, 10); 172 desc->bEndpointAddress |= num; 173 #ifdef MANY_ENDPOINTS 174 } else if (desc->bEndpointAddress & USB_DIR_IN) { 175 if (++in_epnum > 15) 176 return 0; 177 desc->bEndpointAddress = USB_DIR_IN | in_epnum; 178 #endif 179 } else { 180 if (++epnum > 15) 181 return 0; 182 desc->bEndpointAddress |= epnum; 183 } 184 185 /* report (variable) full speed bulk maxpacket */ 186 if (USB_ENDPOINT_XFER_BULK == type) { 187 int size = ep->maxpacket; 188 189 /* min() doesn't work on bitfields with gcc-3.5 */ 190 if (size > 64) 191 size = 64; 192 desc->wMaxPacketSize = cpu_to_le16(size); 193 } 194 return 1; 195 } 196 197 static struct usb_ep * 198 find_ep (struct usb_gadget *gadget, const char *name) 199 { 200 struct usb_ep *ep; 201 202 list_for_each_entry (ep, &gadget->ep_list, ep_list) { 203 if (0 == strcmp (ep->name, name)) 204 return ep; 205 } 206 return NULL; 207 } 208 209 /** 210 * usb_ep_autoconfig - choose an endpoint matching the descriptor 211 * @gadget: The device to which the endpoint must belong. 212 * @desc: Endpoint descriptor, with endpoint direction and transfer mode 213 * initialized. For periodic transfers, the maximum packet 214 * size must also be initialized. This is modified on success. 215 * 216 * By choosing an endpoint to use with the specified descriptor, this 217 * routine simplifies writing gadget drivers that work with multiple 218 * USB device controllers. The endpoint would be passed later to 219 * usb_ep_enable(), along with some descriptor. 220 * 221 * That second descriptor won't always be the same as the first one. 222 * For example, isochronous endpoints can be autoconfigured for high 223 * bandwidth, and then used in several lower bandwidth altsettings. 224 * Also, high and full speed descriptors will be different. 225 * 226 * Be sure to examine and test the results of autoconfiguration on your 227 * hardware. This code may not make the best choices about how to use the 228 * USB controller, and it can't know all the restrictions that may apply. 229 * Some combinations of driver and hardware won't be able to autoconfigure. 230 * 231 * On success, this returns an un-claimed usb_ep, and modifies the endpoint 232 * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value 233 * is initialized as if the endpoint were used at full speed. To prevent 234 * the endpoint from being returned by a later autoconfig call, claim it 235 * by assigning ep->driver_data to some non-null value. 236 * 237 * On failure, this returns a null endpoint descriptor. 238 */ 239 struct usb_ep *usb_ep_autoconfig ( 240 struct usb_gadget *gadget, 241 struct usb_endpoint_descriptor *desc 242 ) 243 { 244 struct usb_ep *ep; 245 u8 type; 246 247 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; 248 249 /* First, apply chip-specific "best usage" knowledge. 250 * This might make a good usb_gadget_ops hook ... 251 */ 252 if (gadget_is_net2280 (gadget) && type == USB_ENDPOINT_XFER_INT) { 253 /* ep-e, ep-f are PIO with only 64 byte fifos */ 254 ep = find_ep (gadget, "ep-e"); 255 if (ep && ep_matches (gadget, ep, desc)) 256 return ep; 257 ep = find_ep (gadget, "ep-f"); 258 if (ep && ep_matches (gadget, ep, desc)) 259 return ep; 260 261 } else if (gadget_is_goku (gadget)) { 262 if (USB_ENDPOINT_XFER_INT == type) { 263 /* single buffering is enough */ 264 ep = find_ep (gadget, "ep3-bulk"); 265 if (ep && ep_matches (gadget, ep, desc)) 266 return ep; 267 } else if (USB_ENDPOINT_XFER_BULK == type 268 && (USB_DIR_IN & desc->bEndpointAddress)) { 269 /* DMA may be available */ 270 ep = find_ep (gadget, "ep2-bulk"); 271 if (ep && ep_matches (gadget, ep, desc)) 272 return ep; 273 } 274 275 #ifdef CONFIG_BLACKFIN 276 } else if (gadget_is_musbhdrc(gadget)) { 277 if ((USB_ENDPOINT_XFER_BULK == type) || 278 (USB_ENDPOINT_XFER_ISOC == type)) { 279 if (USB_DIR_IN & desc->bEndpointAddress) 280 ep = find_ep (gadget, "ep5in"); 281 else 282 ep = find_ep (gadget, "ep6out"); 283 } else if (USB_ENDPOINT_XFER_INT == type) { 284 if (USB_DIR_IN & desc->bEndpointAddress) 285 ep = find_ep(gadget, "ep1in"); 286 else 287 ep = find_ep(gadget, "ep2out"); 288 } else 289 ep = NULL; 290 if (ep && ep_matches (gadget, ep, desc)) 291 return ep; 292 #endif 293 } 294 295 /* Second, look at endpoints until an unclaimed one looks usable */ 296 list_for_each_entry (ep, &gadget->ep_list, ep_list) { 297 if (ep_matches (gadget, ep, desc)) 298 return ep; 299 } 300 301 /* Fail */ 302 return NULL; 303 } 304 305 /** 306 * usb_ep_autoconfig_reset - reset endpoint autoconfig state 307 * @gadget: device for which autoconfig state will be reset 308 * 309 * Use this for devices where one configuration may need to assign 310 * endpoint resources very differently from the next one. It clears 311 * state such as ep->driver_data and the record of assigned endpoints 312 * used by usb_ep_autoconfig(). 313 */ 314 void usb_ep_autoconfig_reset (struct usb_gadget *gadget) 315 { 316 struct usb_ep *ep; 317 318 list_for_each_entry (ep, &gadget->ep_list, ep_list) { 319 ep->driver_data = NULL; 320 } 321 #ifdef MANY_ENDPOINTS 322 in_epnum = 0; 323 #endif 324 epnum = 0; 325 } 326 327