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