1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * dbgp.c -- EHCI Debug Port device gadget 4 * 5 * Copyright (C) 2010 Stephane Duverger 6 * 7 * Released under the GPLv2. 8 */ 9 10 /* verbose messages */ 11 #include <linux/kernel.h> 12 #include <linux/device.h> 13 #include <linux/module.h> 14 #include <linux/usb/ch9.h> 15 #include <linux/usb/gadget.h> 16 17 #include "u_serial.h" 18 19 #define DRIVER_VENDOR_ID 0x0525 /* NetChip */ 20 #define DRIVER_PRODUCT_ID 0xc0de /* undefined */ 21 22 #define USB_DEBUG_MAX_PACKET_SIZE 8 23 #define DBGP_REQ_EP0_LEN 128 24 #define DBGP_REQ_LEN 512 25 26 static struct dbgp { 27 struct usb_gadget *gadget; 28 struct usb_request *req; 29 struct usb_ep *i_ep; 30 struct usb_ep *o_ep; 31 #ifdef CONFIG_USB_G_DBGP_SERIAL 32 struct gserial *serial; 33 #endif 34 } dbgp; 35 36 static struct usb_device_descriptor device_desc = { 37 .bLength = sizeof device_desc, 38 .bDescriptorType = USB_DT_DEVICE, 39 .bcdUSB = cpu_to_le16(0x0200), 40 .bDeviceClass = USB_CLASS_VENDOR_SPEC, 41 .idVendor = cpu_to_le16(DRIVER_VENDOR_ID), 42 .idProduct = cpu_to_le16(DRIVER_PRODUCT_ID), 43 .bNumConfigurations = 1, 44 }; 45 46 static struct usb_debug_descriptor dbg_desc = { 47 .bLength = sizeof dbg_desc, 48 .bDescriptorType = USB_DT_DEBUG, 49 }; 50 51 static struct usb_endpoint_descriptor i_desc = { 52 .bLength = USB_DT_ENDPOINT_SIZE, 53 .bDescriptorType = USB_DT_ENDPOINT, 54 .bmAttributes = USB_ENDPOINT_XFER_BULK, 55 .bEndpointAddress = USB_DIR_IN, 56 }; 57 58 static struct usb_endpoint_descriptor o_desc = { 59 .bLength = USB_DT_ENDPOINT_SIZE, 60 .bDescriptorType = USB_DT_ENDPOINT, 61 .bmAttributes = USB_ENDPOINT_XFER_BULK, 62 .bEndpointAddress = USB_DIR_OUT, 63 }; 64 65 #ifdef CONFIG_USB_G_DBGP_PRINTK 66 static int dbgp_consume(char *buf, unsigned len) 67 { 68 char c; 69 70 if (!len) 71 return 0; 72 73 c = buf[len-1]; 74 if (c != 0) 75 buf[len-1] = 0; 76 77 printk(KERN_NOTICE "%s%c", buf, c); 78 return 0; 79 } 80 81 static void __disable_ep(struct usb_ep *ep) 82 { 83 usb_ep_disable(ep); 84 } 85 86 static void dbgp_disable_ep(void) 87 { 88 __disable_ep(dbgp.i_ep); 89 __disable_ep(dbgp.o_ep); 90 } 91 92 static void dbgp_complete(struct usb_ep *ep, struct usb_request *req) 93 { 94 int stp; 95 int err = 0; 96 int status = req->status; 97 98 if (ep == dbgp.i_ep) { 99 stp = 1; 100 goto fail; 101 } 102 103 if (status != 0) { 104 stp = 2; 105 goto release_req; 106 } 107 108 dbgp_consume(req->buf, req->actual); 109 110 req->length = DBGP_REQ_LEN; 111 err = usb_ep_queue(ep, req, GFP_ATOMIC); 112 if (err < 0) { 113 stp = 3; 114 goto release_req; 115 } 116 117 return; 118 119 release_req: 120 kfree(req->buf); 121 usb_ep_free_request(dbgp.o_ep, req); 122 dbgp_disable_ep(); 123 fail: 124 dev_dbg(&dbgp.gadget->dev, 125 "complete: failure (%d:%d) ==> %d\n", stp, err, status); 126 } 127 128 static int dbgp_enable_ep_req(struct usb_ep *ep) 129 { 130 int err, stp; 131 struct usb_request *req; 132 133 req = usb_ep_alloc_request(ep, GFP_KERNEL); 134 if (!req) { 135 err = -ENOMEM; 136 stp = 1; 137 goto fail_1; 138 } 139 140 req->buf = kmalloc(DBGP_REQ_LEN, GFP_KERNEL); 141 if (!req->buf) { 142 err = -ENOMEM; 143 stp = 2; 144 goto fail_2; 145 } 146 147 req->complete = dbgp_complete; 148 req->length = DBGP_REQ_LEN; 149 err = usb_ep_queue(ep, req, GFP_ATOMIC); 150 if (err < 0) { 151 stp = 3; 152 goto fail_3; 153 } 154 155 return 0; 156 157 fail_3: 158 kfree(req->buf); 159 fail_2: 160 usb_ep_free_request(dbgp.o_ep, req); 161 fail_1: 162 dev_dbg(&dbgp.gadget->dev, 163 "enable ep req: failure (%d:%d)\n", stp, err); 164 return err; 165 } 166 167 static int __enable_ep(struct usb_ep *ep, struct usb_endpoint_descriptor *desc) 168 { 169 int err; 170 ep->desc = desc; 171 err = usb_ep_enable(ep); 172 return err; 173 } 174 175 static int dbgp_enable_ep(void) 176 { 177 int err, stp; 178 179 err = __enable_ep(dbgp.i_ep, &i_desc); 180 if (err < 0) { 181 stp = 1; 182 goto fail_1; 183 } 184 185 err = __enable_ep(dbgp.o_ep, &o_desc); 186 if (err < 0) { 187 stp = 2; 188 goto fail_2; 189 } 190 191 err = dbgp_enable_ep_req(dbgp.o_ep); 192 if (err < 0) { 193 stp = 3; 194 goto fail_3; 195 } 196 197 return 0; 198 199 fail_3: 200 __disable_ep(dbgp.o_ep); 201 fail_2: 202 __disable_ep(dbgp.i_ep); 203 fail_1: 204 dev_dbg(&dbgp.gadget->dev, "enable ep: failure (%d:%d)\n", stp, err); 205 return err; 206 } 207 #endif 208 209 static void dbgp_disconnect(struct usb_gadget *gadget) 210 { 211 #ifdef CONFIG_USB_G_DBGP_PRINTK 212 dbgp_disable_ep(); 213 #else 214 gserial_disconnect(dbgp.serial); 215 #endif 216 } 217 218 static void dbgp_unbind(struct usb_gadget *gadget) 219 { 220 #ifdef CONFIG_USB_G_DBGP_SERIAL 221 kfree(dbgp.serial); 222 dbgp.serial = NULL; 223 #endif 224 if (dbgp.req) { 225 kfree(dbgp.req->buf); 226 usb_ep_free_request(gadget->ep0, dbgp.req); 227 dbgp.req = NULL; 228 } 229 } 230 231 #ifdef CONFIG_USB_G_DBGP_SERIAL 232 static unsigned char tty_line; 233 #endif 234 235 static int dbgp_configure_endpoints(struct usb_gadget *gadget) 236 { 237 int stp; 238 239 usb_ep_autoconfig_reset(gadget); 240 241 dbgp.i_ep = usb_ep_autoconfig(gadget, &i_desc); 242 if (!dbgp.i_ep) { 243 stp = 1; 244 goto fail_1; 245 } 246 247 i_desc.wMaxPacketSize = 248 cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE); 249 250 dbgp.o_ep = usb_ep_autoconfig(gadget, &o_desc); 251 if (!dbgp.o_ep) { 252 stp = 2; 253 goto fail_1; 254 } 255 256 o_desc.wMaxPacketSize = 257 cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE); 258 259 dbg_desc.bDebugInEndpoint = i_desc.bEndpointAddress; 260 dbg_desc.bDebugOutEndpoint = o_desc.bEndpointAddress; 261 262 #ifdef CONFIG_USB_G_DBGP_SERIAL 263 dbgp.serial->in = dbgp.i_ep; 264 dbgp.serial->out = dbgp.o_ep; 265 266 dbgp.serial->in->desc = &i_desc; 267 dbgp.serial->out->desc = &o_desc; 268 #endif 269 270 return 0; 271 272 fail_1: 273 dev_dbg(&dbgp.gadget->dev, "ep config: failure (%d)\n", stp); 274 return -ENODEV; 275 } 276 277 static int dbgp_bind(struct usb_gadget *gadget, 278 struct usb_gadget_driver *driver) 279 { 280 int err, stp; 281 282 dbgp.gadget = gadget; 283 284 dbgp.req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL); 285 if (!dbgp.req) { 286 err = -ENOMEM; 287 stp = 1; 288 goto fail; 289 } 290 291 dbgp.req->buf = kmalloc(DBGP_REQ_EP0_LEN, GFP_KERNEL); 292 if (!dbgp.req->buf) { 293 err = -ENOMEM; 294 stp = 2; 295 goto fail; 296 } 297 298 dbgp.req->length = DBGP_REQ_EP0_LEN; 299 300 #ifdef CONFIG_USB_G_DBGP_SERIAL 301 dbgp.serial = kzalloc(sizeof(struct gserial), GFP_KERNEL); 302 if (!dbgp.serial) { 303 stp = 3; 304 err = -ENOMEM; 305 goto fail; 306 } 307 308 if (gserial_alloc_line(&tty_line)) { 309 stp = 4; 310 err = -ENODEV; 311 goto fail; 312 } 313 #endif 314 315 err = dbgp_configure_endpoints(gadget); 316 if (err < 0) { 317 stp = 5; 318 goto fail; 319 } 320 321 dev_dbg(&dbgp.gadget->dev, "bind: success\n"); 322 return 0; 323 324 fail: 325 dev_dbg(&gadget->dev, "bind: failure (%d:%d)\n", stp, err); 326 dbgp_unbind(gadget); 327 return err; 328 } 329 330 static void dbgp_setup_complete(struct usb_ep *ep, 331 struct usb_request *req) 332 { 333 dev_dbg(&dbgp.gadget->dev, "setup complete: %d, %d/%d\n", 334 req->status, req->actual, req->length); 335 } 336 337 static int dbgp_setup(struct usb_gadget *gadget, 338 const struct usb_ctrlrequest *ctrl) 339 { 340 struct usb_request *req = dbgp.req; 341 u8 request = ctrl->bRequest; 342 u16 value = le16_to_cpu(ctrl->wValue); 343 u16 length = le16_to_cpu(ctrl->wLength); 344 int err = -EOPNOTSUPP; 345 void *data = NULL; 346 u16 len = 0; 347 348 if (request == USB_REQ_GET_DESCRIPTOR) { 349 switch (value>>8) { 350 case USB_DT_DEVICE: 351 dev_dbg(&dbgp.gadget->dev, "setup: desc device\n"); 352 len = sizeof device_desc; 353 data = &device_desc; 354 device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket; 355 break; 356 case USB_DT_DEBUG: 357 dev_dbg(&dbgp.gadget->dev, "setup: desc debug\n"); 358 len = sizeof dbg_desc; 359 data = &dbg_desc; 360 break; 361 default: 362 goto fail; 363 } 364 err = 0; 365 } else if (request == USB_REQ_SET_FEATURE && 366 value == USB_DEVICE_DEBUG_MODE) { 367 dev_dbg(&dbgp.gadget->dev, "setup: feat debug\n"); 368 #ifdef CONFIG_USB_G_DBGP_PRINTK 369 err = dbgp_enable_ep(); 370 #else 371 err = dbgp_configure_endpoints(gadget); 372 if (err < 0) { 373 goto fail; 374 } 375 err = gserial_connect(dbgp.serial, tty_line); 376 #endif 377 if (err < 0) 378 goto fail; 379 } else 380 goto fail; 381 382 req->length = min(length, len); 383 req->zero = len < req->length; 384 if (data && req->length) 385 memcpy(req->buf, data, req->length); 386 387 req->complete = dbgp_setup_complete; 388 return usb_ep_queue(gadget->ep0, req, GFP_ATOMIC); 389 390 fail: 391 dev_dbg(&dbgp.gadget->dev, 392 "setup: failure req %x v %x\n", request, value); 393 return err; 394 } 395 396 static struct usb_gadget_driver dbgp_driver = { 397 .function = "dbgp", 398 .max_speed = USB_SPEED_HIGH, 399 .bind = dbgp_bind, 400 .unbind = dbgp_unbind, 401 .setup = dbgp_setup, 402 .reset = dbgp_disconnect, 403 .disconnect = dbgp_disconnect, 404 .driver = { 405 .owner = THIS_MODULE, 406 .name = "dbgp" 407 }, 408 }; 409 410 static int __init dbgp_init(void) 411 { 412 return usb_gadget_probe_driver(&dbgp_driver); 413 } 414 415 static void __exit dbgp_exit(void) 416 { 417 usb_gadget_unregister_driver(&dbgp_driver); 418 #ifdef CONFIG_USB_G_DBGP_SERIAL 419 gserial_free_line(tty_line); 420 #endif 421 } 422 423 MODULE_AUTHOR("Stephane Duverger"); 424 MODULE_LICENSE("GPL"); 425 module_init(dbgp_init); 426 module_exit(dbgp_exit); 427