drivers/usb/gadget/dbgp.c

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