1 /* 2 * epautoconf.c -- endpoint autoconfiguration for usb gadget drivers 3 * 4 * Copyright (C) 2004 David Brownell 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 * 8 * SPDX-License-Identifier: GPL-2.0+ 9 * 10 * Ported to U-boot by: Thomas Smits <ts.smits@gmail.com> and 11 * Remy Bohmer <linux@bohmer.net> 12 */ 13 14 #include <common.h> 15 #include <linux/usb/ch9.h> 16 #include <asm/errno.h> 17 #include <linux/usb/gadget.h> 18 #include <asm/unaligned.h> 19 #include "gadget_chips.h" 20 21 #define isdigit(c) ('0' <= (c) && (c) <= '9') 22 23 /* we must assign addresses for configurable endpoints (like net2280) */ 24 static unsigned epnum; 25 26 /* #define MANY_ENDPOINTS */ 27 #ifdef MANY_ENDPOINTS 28 /* more than 15 configurable endpoints */ 29 static unsigned in_epnum; 30 #endif 31 32 33 /* 34 * This should work with endpoints from controller drivers sharing the 35 * same endpoint naming convention. By example: 36 * 37 * - ep1, ep2, ... address is fixed, not direction or type 38 * - ep1in, ep2out, ... address and direction are fixed, not type 39 * - ep1-bulk, ep2-bulk, ... address and type are fixed, not direction 40 * - ep1in-bulk, ep2out-iso, ... all three are fixed 41 * - ep-* ... no functionality restrictions 42 * 43 * Type suffixes are "-bulk", "-iso", or "-int". Numbers are decimal. 44 * Less common restrictions are implied by gadget_is_*(). 45 * 46 * NOTE: each endpoint is unidirectional, as specified by its USB 47 * descriptor; and isn't specific to a configuration or altsetting. 48 */ 49 static int ep_matches( 50 struct usb_gadget *gadget, 51 struct usb_ep *ep, 52 struct usb_endpoint_descriptor *desc 53 ) 54 { 55 u8 type; 56 const char *tmp; 57 u16 max; 58 59 /* endpoint already claimed? */ 60 if (NULL != ep->driver_data) 61 return 0; 62 63 /* only support ep0 for portable CONTROL traffic */ 64 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; 65 if (USB_ENDPOINT_XFER_CONTROL == type) 66 return 0; 67 68 /* some other naming convention */ 69 if ('e' != ep->name[0]) 70 return 0; 71 72 /* type-restriction: "-iso", "-bulk", or "-int". 73 * direction-restriction: "in", "out". 74 */ 75 if ('-' != ep->name[2]) { 76 tmp = strrchr(ep->name, '-'); 77 if (tmp) { 78 switch (type) { 79 case USB_ENDPOINT_XFER_INT: 80 /* bulk endpoints handle interrupt transfers, 81 * except the toggle-quirky iso-synch kind 82 */ 83 if ('s' == tmp[2]) /* == "-iso" */ 84 return 0; 85 /* for now, avoid PXA "interrupt-in"; 86 * it's documented as never using DATA1. 87 */ 88 if (gadget_is_pxa(gadget) 89 && 'i' == tmp[1]) 90 return 0; 91 break; 92 case USB_ENDPOINT_XFER_BULK: 93 if ('b' != tmp[1]) /* != "-bulk" */ 94 return 0; 95 break; 96 case USB_ENDPOINT_XFER_ISOC: 97 if ('s' != tmp[2]) /* != "-iso" */ 98 return 0; 99 } 100 } else { 101 tmp = ep->name + strlen(ep->name); 102 } 103 104 /* direction-restriction: "..in-..", "out-.." */ 105 tmp--; 106 if (!isdigit(*tmp)) { 107 if (desc->bEndpointAddress & USB_DIR_IN) { 108 if ('n' != *tmp) 109 return 0; 110 } else { 111 if ('t' != *tmp) 112 return 0; 113 } 114 } 115 } 116 117 /* endpoint maxpacket size is an input parameter, except for bulk 118 * where it's an output parameter representing the full speed limit. 119 * the usb spec fixes high speed bulk maxpacket at 512 bytes. 120 */ 121 max = 0x7ff & le16_to_cpu(get_unaligned(&desc->wMaxPacketSize)); 122 switch (type) { 123 case USB_ENDPOINT_XFER_INT: 124 /* INT: limit 64 bytes full speed, 1024 high speed */ 125 if (!gadget->is_dualspeed && max > 64) 126 return 0; 127 /* FALLTHROUGH */ 128 129 case USB_ENDPOINT_XFER_ISOC: 130 /* ISO: limit 1023 bytes full speed, 1024 high speed */ 131 if (ep->maxpacket < max) 132 return 0; 133 if (!gadget->is_dualspeed && max > 1023) 134 return 0; 135 136 /* BOTH: "high bandwidth" works only at high speed */ 137 if ((get_unaligned(&desc->wMaxPacketSize) & 138 __constant_cpu_to_le16(3<<11))) { 139 if (!gadget->is_dualspeed) 140 return 0; 141 /* configure your hardware with enough buffering!! */ 142 } 143 break; 144 } 145 146 /* MATCH!! */ 147 148 /* report address */ 149 if (isdigit(ep->name[2])) { 150 u8 num = simple_strtoul(&ep->name[2], NULL, 10); 151 desc->bEndpointAddress |= num; 152 #ifdef MANY_ENDPOINTS 153 } else if (desc->bEndpointAddress & USB_DIR_IN) { 154 if (++in_epnum > 15) 155 return 0; 156 desc->bEndpointAddress = USB_DIR_IN | in_epnum; 157 #endif 158 } else { 159 if (++epnum > 15) 160 return 0; 161 desc->bEndpointAddress |= epnum; 162 } 163 164 /* report (variable) full speed bulk maxpacket */ 165 if (USB_ENDPOINT_XFER_BULK == type) { 166 int size = ep->maxpacket; 167 168 /* min() doesn't work on bitfields with gcc-3.5 */ 169 if (size > 64) 170 size = 64; 171 put_unaligned(cpu_to_le16(size), &desc->wMaxPacketSize); 172 } 173 return 1; 174 } 175 176 static struct usb_ep * 177 find_ep(struct usb_gadget *gadget, const char *name) 178 { 179 struct usb_ep *ep; 180 181 list_for_each_entry(ep, &gadget->ep_list, ep_list) { 182 if (0 == strcmp(ep->name, name)) 183 return ep; 184 } 185 return NULL; 186 } 187 188 /** 189 * usb_ep_autoconfig - choose an endpoint matching the descriptor 190 * @gadget: The device to which the endpoint must belong. 191 * @desc: Endpoint descriptor, with endpoint direction and transfer mode 192 * initialized. For periodic transfers, the maximum packet 193 * size must also be initialized. This is modified on success. 194 * 195 * By choosing an endpoint to use with the specified descriptor, this 196 * routine simplifies writing gadget drivers that work with multiple 197 * USB device controllers. The endpoint would be passed later to 198 * usb_ep_enable(), along with some descriptor. 199 * 200 * That second descriptor won't always be the same as the first one. 201 * For example, isochronous endpoints can be autoconfigured for high 202 * bandwidth, and then used in several lower bandwidth altsettings. 203 * Also, high and full speed descriptors will be different. 204 * 205 * Be sure to examine and test the results of autoconfiguration on your 206 * hardware. This code may not make the best choices about how to use the 207 * USB controller, and it can't know all the restrictions that may apply. 208 * Some combinations of driver and hardware won't be able to autoconfigure. 209 * 210 * On success, this returns an un-claimed usb_ep, and modifies the endpoint 211 * descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value 212 * is initialized as if the endpoint were used at full speed. To prevent 213 * the endpoint from being returned by a later autoconfig call, claim it 214 * by assigning ep->driver_data to some non-null value. 215 * 216 * On failure, this returns a null endpoint descriptor. 217 */ 218 struct usb_ep *usb_ep_autoconfig( 219 struct usb_gadget *gadget, 220 struct usb_endpoint_descriptor *desc 221 ) 222 { 223 struct usb_ep *ep; 224 u8 type; 225 226 type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK; 227 228 /* First, apply chip-specific "best usage" knowledge. 229 * This might make a good usb_gadget_ops hook ... 230 */ 231 if (gadget_is_net2280(gadget) && type == USB_ENDPOINT_XFER_INT) { 232 /* ep-e, ep-f are PIO with only 64 byte fifos */ 233 ep = find_ep(gadget, "ep-e"); 234 if (ep && ep_matches(gadget, ep, desc)) 235 return ep; 236 ep = find_ep(gadget, "ep-f"); 237 if (ep && ep_matches(gadget, ep, desc)) 238 return ep; 239 240 } else if (gadget_is_goku(gadget)) { 241 if (USB_ENDPOINT_XFER_INT == type) { 242 /* single buffering is enough */ 243 ep = find_ep(gadget, "ep3-bulk"); 244 if (ep && ep_matches(gadget, ep, desc)) 245 return ep; 246 } else if (USB_ENDPOINT_XFER_BULK == type 247 && (USB_DIR_IN & desc->bEndpointAddress)) { 248 /* DMA may be available */ 249 ep = find_ep(gadget, "ep2-bulk"); 250 if (ep && ep_matches(gadget, ep, desc)) 251 return ep; 252 } 253 254 } else if (gadget_is_sh(gadget) && USB_ENDPOINT_XFER_INT == type) { 255 /* single buffering is enough; maybe 8 byte fifo is too */ 256 ep = find_ep(gadget, "ep3in-bulk"); 257 if (ep && ep_matches(gadget, ep, desc)) 258 return ep; 259 260 } else if (gadget_is_mq11xx(gadget) && USB_ENDPOINT_XFER_INT == type) { 261 ep = find_ep(gadget, "ep1-bulk"); 262 if (ep && ep_matches(gadget, ep, desc)) 263 return ep; 264 } 265 266 /* Second, look at endpoints until an unclaimed one looks usable */ 267 list_for_each_entry(ep, &gadget->ep_list, ep_list) { 268 if (ep_matches(gadget, ep, desc)) 269 return ep; 270 } 271 272 /* Fail */ 273 return NULL; 274 } 275 276 /** 277 * usb_ep_autoconfig_reset - reset endpoint autoconfig state 278 * @gadget: device for which autoconfig state will be reset 279 * 280 * Use this for devices where one configuration may need to assign 281 * endpoint resources very differently from the next one. It clears 282 * state such as ep->driver_data and the record of assigned endpoints 283 * used by usb_ep_autoconfig(). 284 */ 285 void usb_ep_autoconfig_reset(struct usb_gadget *gadget) 286 { 287 struct usb_ep *ep; 288 289 list_for_each_entry(ep, &gadget->ep_list, ep_list) { 290 ep->driver_data = NULL; 291 } 292 #ifdef MANY_ENDPOINTS 293 in_epnum = 0; 294 #endif 295 epnum = 0; 296 } 297