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 * Ported to U-boot by: Thomas Smits <ts.smits@gmail.com> and 21 * Remy Bohmer <linux@bohmer.net> 22 */ 23 24 #include <common.h> 25 #include <linux/usb/ch9.h> 26 #include <asm/errno.h> 27 #include <linux/usb/gadget.h> 28 #include "gadget_chips.h" 29 30 #define isdigit(c) ('0' <= (c) && (c) <= '9') 31 32 /* we must assign addresses for configurable endpoints (like net2280) */ 33 static unsigned epnum; 34 35 /* #define MANY_ENDPOINTS */ 36 #ifdef MANY_ENDPOINTS 37 /* more than 15 configurable endpoints */ 38 static unsigned in_epnum; 39 #endif 40 41 42 /* 43 * This should work with endpoints from controller drivers sharing the 44 * same endpoint naming convention. By example: 45 * 46 * - ep1, ep2, ... address is fixed, not direction or type 47 * - ep1in, ep2out, ... address and direction are fixed, not type 48 * - ep1-bulk, ep2-bulk, ... address and type are fixed, not direction 49 * - ep1in-bulk, ep2out-iso, ... all three are fixed 50 * - ep-* ... no functionality restrictions 51 * 52 * Type suffixes are "-bulk", "-iso", or "-int". Numbers are decimal. 53 * Less common restrictions are implied by gadget_is_*(). 54 * 55 * NOTE: each endpoint is unidirectional, as specified by its USB 56 * descriptor; and isn't specific to a configuration or altsetting. 57 */ 58 static int ep_matches( 59 struct usb_gadget *gadget, 60 struct usb_ep *ep, 61 struct usb_endpoint_descriptor *desc 62 ) 63 { 64 u8 type; 65 const char *tmp; 66 u16 max; 67 68 /* endpoint already claimed? */ 69 if (NULL != ep->driver_data) 70 return 0; 71 72 /* only support ep0 for portable CONTROL traffic */ 73 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; 74 if (USB_ENDPOINT_XFER_CONTROL == type) 75 return 0; 76 77 /* some other naming convention */ 78 if ('e' != ep->name[0]) 79 return 0; 80 81 /* type-restriction: "-iso", "-bulk", or "-int". 82 * direction-restriction: "in", "out". 83 */ 84 if ('-' != ep->name[2]) { 85 tmp = strrchr(ep->name, '-'); 86 if (tmp) { 87 switch (type) { 88 case USB_ENDPOINT_XFER_INT: 89 /* bulk endpoints handle interrupt transfers, 90 * except the toggle-quirky iso-synch kind 91 */ 92 if ('s' == tmp[2]) /* == "-iso" */ 93 return 0; 94 /* for now, avoid PXA "interrupt-in"; 95 * it's documented as never using DATA1. 96 */ 97 if (gadget_is_pxa(gadget) 98 && 'i' == tmp[1]) 99 return 0; 100 break; 101 case USB_ENDPOINT_XFER_BULK: 102 if ('b' != tmp[1]) /* != "-bulk" */ 103 return 0; 104 break; 105 case USB_ENDPOINT_XFER_ISOC: 106 if ('s' != tmp[2]) /* != "-iso" */ 107 return 0; 108 } 109 } else { 110 tmp = ep->name + strlen(ep->name); 111 } 112 113 /* direction-restriction: "..in-..", "out-.." */ 114 tmp--; 115 if (!isdigit(*tmp)) { 116 if (desc->bEndpointAddress & USB_DIR_IN) { 117 if ('n' != *tmp) 118 return 0; 119 } else { 120 if ('t' != *tmp) 121 return 0; 122 } 123 } 124 } 125 126 /* endpoint maxpacket size is an input parameter, except for bulk 127 * where it's an output parameter representing the full speed limit. 128 * the usb spec fixes high speed bulk maxpacket at 512 bytes. 129 */ 130 max = 0x7ff & le16_to_cpu(desc->wMaxPacketSize); 131 switch (type) { 132 case USB_ENDPOINT_XFER_INT: 133 /* INT: limit 64 bytes full speed, 1024 high speed */ 134 if (!gadget->is_dualspeed && max > 64) 135 return 0; 136 /* FALLTHROUGH */ 137 138 case USB_ENDPOINT_XFER_ISOC: 139 /* ISO: limit 1023 bytes full speed, 1024 high speed */ 140 if (ep->maxpacket < max) 141 return 0; 142 if (!gadget->is_dualspeed && max > 1023) 143 return 0; 144 145 /* BOTH: "high bandwidth" works only at high speed */ 146 if ((desc->wMaxPacketSize & __constant_cpu_to_le16(3<<11))) { 147 if (!gadget->is_dualspeed) 148 return 0; 149 /* configure your hardware with enough buffering!! */ 150 } 151 break; 152 } 153 154 /* MATCH!! */ 155 156 /* report address */ 157 if (isdigit(ep->name[2])) { 158 u8 num = simple_strtoul(&ep->name[2], NULL, 10); 159 desc->bEndpointAddress |= num; 160 #ifdef MANY_ENDPOINTS 161 } else if (desc->bEndpointAddress & USB_DIR_IN) { 162 if (++in_epnum > 15) 163 return 0; 164 desc->bEndpointAddress = USB_DIR_IN | in_epnum; 165 #endif 166 } else { 167 if (++epnum > 15) 168 return 0; 169 desc->bEndpointAddress |= epnum; 170 } 171 172 /* report (variable) full speed bulk maxpacket */ 173 if (USB_ENDPOINT_XFER_BULK == type) { 174 int size = ep->maxpacket; 175 176 /* min() doesn't work on bitfields with gcc-3.5 */ 177 if (size > 64) 178 size = 64; 179 desc->wMaxPacketSize = cpu_to_le16(size); 180 } 181 return 1; 182 } 183 184 static struct usb_ep * 185 find_ep(struct usb_gadget *gadget, const char *name) 186 { 187 struct usb_ep *ep; 188 189 list_for_each_entry(ep, &gadget->ep_list, ep_list) { 190 if (0 == strcmp(ep->name, name)) 191 return ep; 192 } 193 return NULL; 194 } 195 196 /** 197 * usb_ep_autoconfig - choose an endpoint matching the descriptor 198 * @gadget: The device to which the endpoint must belong. 199 * @desc: Endpoint descriptor, with endpoint direction and transfer mode 200 * initialized. For periodic transfers, the maximum packet 201 * size must also be initialized. This is modified on success. 202 * 203 * By choosing an endpoint to use with the specified descriptor, this 204 * routine simplifies writing gadget drivers that work with multiple 205 * USB device controllers. The endpoint would be passed later to 206 * usb_ep_enable(), along with some descriptor. 207 * 208 * That second descriptor won't always be the same as the first one. 209 * For example, isochronous endpoints can be autoconfigured for high 210 * bandwidth, and then used in several lower bandwidth altsettings. 211 * Also, high and full speed descriptors will be different. 212 * 213 * Be sure to examine and test the results of autoconfiguration on your 214 * hardware. This code may not make the best choices about how to use the 215 * USB controller, and it can't know all the restrictions that may apply. 216 * Some combinations of driver and hardware won't be able to autoconfigure. 217 * 218 * On success, this returns an un-claimed usb_ep, and modifies the endpoint 219 * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value 220 * is initialized as if the endpoint were used at full speed. To prevent 221 * the endpoint from being returned by a later autoconfig call, claim it 222 * by assigning ep->driver_data to some non-null value. 223 * 224 * On failure, this returns a null endpoint descriptor. 225 */ 226 struct usb_ep *usb_ep_autoconfig( 227 struct usb_gadget *gadget, 228 struct usb_endpoint_descriptor *desc 229 ) 230 { 231 struct usb_ep *ep; 232 u8 type; 233 234 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; 235 236 /* First, apply chip-specific "best usage" knowledge. 237 * This might make a good usb_gadget_ops hook ... 238 */ 239 if (gadget_is_net2280(gadget) && type == USB_ENDPOINT_XFER_INT) { 240 /* ep-e, ep-f are PIO with only 64 byte fifos */ 241 ep = find_ep(gadget, "ep-e"); 242 if (ep && ep_matches(gadget, ep, desc)) 243 return ep; 244 ep = find_ep(gadget, "ep-f"); 245 if (ep && ep_matches(gadget, ep, desc)) 246 return ep; 247 248 } else if (gadget_is_goku(gadget)) { 249 if (USB_ENDPOINT_XFER_INT == type) { 250 /* single buffering is enough */ 251 ep = find_ep(gadget, "ep3-bulk"); 252 if (ep && ep_matches(gadget, ep, desc)) 253 return ep; 254 } else if (USB_ENDPOINT_XFER_BULK == type 255 && (USB_DIR_IN & desc->bEndpointAddress)) { 256 /* DMA may be available */ 257 ep = find_ep(gadget, "ep2-bulk"); 258 if (ep && ep_matches(gadget, ep, desc)) 259 return ep; 260 } 261 262 } else if (gadget_is_sh(gadget) && USB_ENDPOINT_XFER_INT == type) { 263 /* single buffering is enough; maybe 8 byte fifo is too */ 264 ep = find_ep(gadget, "ep3in-bulk"); 265 if (ep && ep_matches(gadget, ep, desc)) 266 return ep; 267 268 } else if (gadget_is_mq11xx(gadget) && USB_ENDPOINT_XFER_INT == type) { 269 ep = find_ep(gadget, "ep1-bulk"); 270 if (ep && ep_matches(gadget, ep, desc)) 271 return ep; 272 } 273 274 /* Second, look at endpoints until an unclaimed one looks usable */ 275 list_for_each_entry(ep, &gadget->ep_list, ep_list) { 276 if (ep_matches(gadget, ep, desc)) 277 return ep; 278 } 279 280 /* Fail */ 281 return NULL; 282 } 283 284 /** 285 * usb_ep_autoconfig_reset - reset endpoint autoconfig state 286 * @gadget: device for which autoconfig state will be reset 287 * 288 * Use this for devices where one configuration may need to assign 289 * endpoint resources very differently from the next one. It clears 290 * state such as ep->driver_data and the record of assigned endpoints 291 * used by usb_ep_autoconfig(). 292 */ 293 void usb_ep_autoconfig_reset(struct usb_gadget *gadget) 294 { 295 struct usb_ep *ep; 296 297 list_for_each_entry(ep, &gadget->ep_list, ep_list) { 298 ep->driver_data = NULL; 299 } 300 #ifdef MANY_ENDPOINTS 301 in_epnum = 0; 302 #endif 303 epnum = 0; 304 } 305