1 /* 2 * dbgp.c -- EHCI Debug Port device gadget 3 * 4 * Copyright (C) 2010 Stephane Duverger 5 * 6 * Released under the GPLv2. 7 */ 8 9 /* verbose messages */ 10 #include <linux/kernel.h> 11 #include <linux/device.h> 12 #include <linux/module.h> 13 #include <linux/usb/ch9.h> 14 #include <linux/usb/gadget.h> 15 16 #include "u_serial.h" 17 18 #define DRIVER_VENDOR_ID 0x0525 /* NetChip */ 19 #define DRIVER_PRODUCT_ID 0xc0de /* undefined */ 20 21 #define USB_DEBUG_MAX_PACKET_SIZE 8 22 #define DBGP_REQ_EP0_LEN 128 23 #define DBGP_REQ_LEN 512 24 25 static struct dbgp { 26 struct usb_gadget *gadget; 27 struct usb_request *req; 28 struct usb_ep *i_ep; 29 struct usb_ep *o_ep; 30 #ifdef CONFIG_USB_G_DBGP_SERIAL 31 struct gserial *serial; 32 #endif 33 } dbgp; 34 35 static struct usb_device_descriptor device_desc = { 36 .bLength = sizeof device_desc, 37 .bDescriptorType = USB_DT_DEVICE, 38 .bcdUSB = __constant_cpu_to_le16(0x0200), 39 .bDeviceClass = USB_CLASS_VENDOR_SPEC, 40 .idVendor = __constant_cpu_to_le16(DRIVER_VENDOR_ID), 41 .idProduct = __constant_cpu_to_le16(DRIVER_PRODUCT_ID), 42 .bNumConfigurations = 1, 43 }; 44 45 static struct usb_debug_descriptor dbg_desc = { 46 .bLength = sizeof dbg_desc, 47 .bDescriptorType = USB_DT_DEBUG, 48 }; 49 50 static struct usb_endpoint_descriptor i_desc = { 51 .bLength = USB_DT_ENDPOINT_SIZE, 52 .bDescriptorType = USB_DT_ENDPOINT, 53 .bmAttributes = USB_ENDPOINT_XFER_BULK, 54 .bEndpointAddress = USB_DIR_IN, 55 }; 56 57 static struct usb_endpoint_descriptor o_desc = { 58 .bLength = USB_DT_ENDPOINT_SIZE, 59 .bDescriptorType = USB_DT_ENDPOINT, 60 .bmAttributes = USB_ENDPOINT_XFER_BULK, 61 .bEndpointAddress = USB_DIR_OUT, 62 }; 63 64 #ifdef CONFIG_USB_G_DBGP_PRINTK 65 static int dbgp_consume(char *buf, unsigned len) 66 { 67 char c; 68 69 if (!len) 70 return 0; 71 72 c = buf[len-1]; 73 if (c != 0) 74 buf[len-1] = 0; 75 76 printk(KERN_NOTICE "%s%c", buf, c); 77 return 0; 78 } 79 80 static void __disable_ep(struct usb_ep *ep) 81 { 82 if (ep && ep->driver_data == dbgp.gadget) { 83 usb_ep_disable(ep); 84 ep->driver_data = NULL; 85 } 86 } 87 88 static void dbgp_disable_ep(void) 89 { 90 __disable_ep(dbgp.i_ep); 91 __disable_ep(dbgp.o_ep); 92 } 93 94 static void dbgp_complete(struct usb_ep *ep, struct usb_request *req) 95 { 96 int stp; 97 int err = 0; 98 int status = req->status; 99 100 if (ep == dbgp.i_ep) { 101 stp = 1; 102 goto fail; 103 } 104 105 if (status != 0) { 106 stp = 2; 107 goto release_req; 108 } 109 110 dbgp_consume(req->buf, req->actual); 111 112 req->length = DBGP_REQ_LEN; 113 err = usb_ep_queue(ep, req, GFP_ATOMIC); 114 if (err < 0) { 115 stp = 3; 116 goto release_req; 117 } 118 119 return; 120 121 release_req: 122 kfree(req->buf); 123 usb_ep_free_request(dbgp.o_ep, req); 124 dbgp_disable_ep(); 125 fail: 126 dev_dbg(&dbgp.gadget->dev, 127 "complete: failure (%d:%d) ==> %d\n", stp, err, status); 128 } 129 130 static int dbgp_enable_ep_req(struct usb_ep *ep) 131 { 132 int err, stp; 133 struct usb_request *req; 134 135 req = usb_ep_alloc_request(ep, GFP_KERNEL); 136 if (!req) { 137 err = -ENOMEM; 138 stp = 1; 139 goto fail_1; 140 } 141 142 req->buf = kmalloc(DBGP_REQ_LEN, GFP_KERNEL); 143 if (!req->buf) { 144 err = -ENOMEM; 145 stp = 2; 146 goto fail_2; 147 } 148 149 req->complete = dbgp_complete; 150 req->length = DBGP_REQ_LEN; 151 err = usb_ep_queue(ep, req, GFP_ATOMIC); 152 if (err < 0) { 153 stp = 3; 154 goto fail_3; 155 } 156 157 return 0; 158 159 fail_3: 160 kfree(req->buf); 161 fail_2: 162 usb_ep_free_request(dbgp.o_ep, req); 163 fail_1: 164 dev_dbg(&dbgp.gadget->dev, 165 "enable ep req: failure (%d:%d)\n", stp, err); 166 return err; 167 } 168 169 static int __enable_ep(struct usb_ep *ep, struct usb_endpoint_descriptor *desc) 170 { 171 int err; 172 ep->desc = desc; 173 err = usb_ep_enable(ep); 174 ep->driver_data = dbgp.gadget; 175 return err; 176 } 177 178 static int dbgp_enable_ep(void) 179 { 180 int err, stp; 181 182 err = __enable_ep(dbgp.i_ep, &i_desc); 183 if (err < 0) { 184 stp = 1; 185 goto fail_1; 186 } 187 188 err = __enable_ep(dbgp.o_ep, &o_desc); 189 if (err < 0) { 190 stp = 2; 191 goto fail_2; 192 } 193 194 err = dbgp_enable_ep_req(dbgp.o_ep); 195 if (err < 0) { 196 stp = 3; 197 goto fail_3; 198 } 199 200 return 0; 201 202 fail_3: 203 __disable_ep(dbgp.o_ep); 204 fail_2: 205 __disable_ep(dbgp.i_ep); 206 fail_1: 207 dev_dbg(&dbgp.gadget->dev, "enable ep: failure (%d:%d)\n", stp, err); 208 return err; 209 } 210 #endif 211 212 static void dbgp_disconnect(struct usb_gadget *gadget) 213 { 214 #ifdef CONFIG_USB_G_DBGP_PRINTK 215 dbgp_disable_ep(); 216 #else 217 gserial_disconnect(dbgp.serial); 218 #endif 219 } 220 221 static void dbgp_unbind(struct usb_gadget *gadget) 222 { 223 #ifdef CONFIG_USB_G_DBGP_SERIAL 224 kfree(dbgp.serial); 225 dbgp.serial = NULL; 226 #endif 227 if (dbgp.req) { 228 kfree(dbgp.req->buf); 229 usb_ep_free_request(gadget->ep0, dbgp.req); 230 dbgp.req = NULL; 231 } 232 233 gadget->ep0->driver_data = NULL; 234 } 235 236 #ifdef CONFIG_USB_G_DBGP_SERIAL 237 static unsigned char tty_line; 238 #endif 239 240 static int dbgp_configure_endpoints(struct usb_gadget *gadget) 241 { 242 int stp; 243 244 usb_ep_autoconfig_reset(gadget); 245 246 dbgp.i_ep = usb_ep_autoconfig(gadget, &i_desc); 247 if (!dbgp.i_ep) { 248 stp = 1; 249 goto fail_1; 250 } 251 252 dbgp.i_ep->driver_data = gadget; 253 i_desc.wMaxPacketSize = 254 __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE); 255 256 dbgp.o_ep = usb_ep_autoconfig(gadget, &o_desc); 257 if (!dbgp.o_ep) { 258 dbgp.i_ep->driver_data = NULL; 259 stp = 2; 260 goto fail_2; 261 } 262 263 dbgp.o_ep->driver_data = gadget; 264 o_desc.wMaxPacketSize = 265 __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE); 266 267 dbg_desc.bDebugInEndpoint = i_desc.bEndpointAddress; 268 dbg_desc.bDebugOutEndpoint = o_desc.bEndpointAddress; 269 270 #ifdef CONFIG_USB_G_DBGP_SERIAL 271 dbgp.serial->in = dbgp.i_ep; 272 dbgp.serial->out = dbgp.o_ep; 273 274 dbgp.serial->in->desc = &i_desc; 275 dbgp.serial->out->desc = &o_desc; 276 #endif 277 278 return 0; 279 280 fail_2: 281 dbgp.i_ep->driver_data = NULL; 282 fail_1: 283 dev_dbg(&dbgp.gadget->dev, "ep config: failure (%d)\n", stp); 284 return -ENODEV; 285 } 286 287 static int dbgp_bind(struct usb_gadget *gadget, 288 struct usb_gadget_driver *driver) 289 { 290 int err, stp; 291 292 dbgp.gadget = gadget; 293 294 dbgp.req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL); 295 if (!dbgp.req) { 296 err = -ENOMEM; 297 stp = 1; 298 goto fail; 299 } 300 301 dbgp.req->buf = kmalloc(DBGP_REQ_EP0_LEN, GFP_KERNEL); 302 if (!dbgp.req->buf) { 303 err = -ENOMEM; 304 stp = 2; 305 goto fail; 306 } 307 308 dbgp.req->length = DBGP_REQ_EP0_LEN; 309 gadget->ep0->driver_data = gadget; 310 311 #ifdef CONFIG_USB_G_DBGP_SERIAL 312 dbgp.serial = kzalloc(sizeof(struct gserial), GFP_KERNEL); 313 if (!dbgp.serial) { 314 stp = 3; 315 err = -ENOMEM; 316 goto fail; 317 } 318 319 if (gserial_alloc_line(&tty_line)) { 320 stp = 4; 321 err = -ENODEV; 322 goto fail; 323 } 324 #endif 325 326 err = dbgp_configure_endpoints(gadget); 327 if (err < 0) { 328 stp = 5; 329 goto fail; 330 } 331 332 dev_dbg(&dbgp.gadget->dev, "bind: success\n"); 333 return 0; 334 335 fail: 336 dev_dbg(&gadget->dev, "bind: failure (%d:%d)\n", stp, err); 337 dbgp_unbind(gadget); 338 return err; 339 } 340 341 static void dbgp_setup_complete(struct usb_ep *ep, 342 struct usb_request *req) 343 { 344 dev_dbg(&dbgp.gadget->dev, "setup complete: %d, %d/%d\n", 345 req->status, req->actual, req->length); 346 } 347 348 static int dbgp_setup(struct usb_gadget *gadget, 349 const struct usb_ctrlrequest *ctrl) 350 { 351 struct usb_request *req = dbgp.req; 352 u8 request = ctrl->bRequest; 353 u16 value = le16_to_cpu(ctrl->wValue); 354 u16 length = le16_to_cpu(ctrl->wLength); 355 int err = -EOPNOTSUPP; 356 void *data = NULL; 357 u16 len = 0; 358 359 gadget->ep0->driver_data = gadget; 360 361 if (request == USB_REQ_GET_DESCRIPTOR) { 362 switch (value>>8) { 363 case USB_DT_DEVICE: 364 dev_dbg(&dbgp.gadget->dev, "setup: desc device\n"); 365 len = sizeof device_desc; 366 data = &device_desc; 367 device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket; 368 break; 369 case USB_DT_DEBUG: 370 dev_dbg(&dbgp.gadget->dev, "setup: desc debug\n"); 371 len = sizeof dbg_desc; 372 data = &dbg_desc; 373 break; 374 default: 375 goto fail; 376 } 377 err = 0; 378 } else if (request == USB_REQ_SET_FEATURE && 379 value == USB_DEVICE_DEBUG_MODE) { 380 dev_dbg(&dbgp.gadget->dev, "setup: feat debug\n"); 381 #ifdef CONFIG_USB_G_DBGP_PRINTK 382 err = dbgp_enable_ep(); 383 #else 384 err = dbgp_configure_endpoints(gadget); 385 if (err < 0) { 386 goto fail; 387 } 388 err = gserial_connect(dbgp.serial, tty_line); 389 #endif 390 if (err < 0) 391 goto fail; 392 } else 393 goto fail; 394 395 req->length = min(length, len); 396 req->zero = len < req->length; 397 if (data && req->length) 398 memcpy(req->buf, data, req->length); 399 400 req->complete = dbgp_setup_complete; 401 return usb_ep_queue(gadget->ep0, req, GFP_ATOMIC); 402 403 fail: 404 dev_dbg(&dbgp.gadget->dev, 405 "setup: failure req %x v %x\n", request, value); 406 return err; 407 } 408 409 static struct usb_gadget_driver dbgp_driver = { 410 .function = "dbgp", 411 .max_speed = USB_SPEED_HIGH, 412 .bind = dbgp_bind, 413 .unbind = dbgp_unbind, 414 .setup = dbgp_setup, 415 .reset = dbgp_disconnect, 416 .disconnect = dbgp_disconnect, 417 .driver = { 418 .owner = THIS_MODULE, 419 .name = "dbgp" 420 }, 421 }; 422 423 static int __init dbgp_init(void) 424 { 425 return usb_gadget_probe_driver(&dbgp_driver); 426 } 427 428 static void __exit dbgp_exit(void) 429 { 430 usb_gadget_unregister_driver(&dbgp_driver); 431 #ifdef CONFIG_USB_G_DBGP_SERIAL 432 gserial_free_line(tty_line); 433 #endif 434 } 435 436 MODULE_AUTHOR("Stephane Duverger"); 437 MODULE_LICENSE("GPL"); 438 module_init(dbgp_init); 439 module_exit(dbgp_exit); 440