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