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
  10 /* verbose messages */
  11 #include <linux/kernel.h>
  12 #include <linux/device.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 = usb_ep_enable(ep, desc);
 177         ep->driver_data = dbgp.gadget;
 178         return err;
 179 }
 180
 181 static int dbgp_enable_ep(void)
 182 {
 183         int err, stp;
 184
 185         err = __enable_ep(dbgp.i_ep, &i_desc);
 186         if (err < 0) {
 187                 stp = 1;
 188                 goto fail_1;
 189         }
 190
 191         err = __enable_ep(dbgp.o_ep, &o_desc);
 192         if (err < 0) {
 193                 stp = 2;
 194                 goto fail_2;
 195         }
 196
 197         err = dbgp_enable_ep_req(dbgp.o_ep);
 198         if (err < 0) {
 199                 stp = 3;
 200                 goto fail_3;
 201         }
 202
 203         return 0;
 204
 205 fail_3:
 206         __disable_ep(dbgp.o_ep);
 207 fail_2:
 208         __disable_ep(dbgp.i_ep);
 209 fail_1:
 210         dev_dbg(&dbgp.gadget->dev, "enable ep: failure (%d:%d)\n", stp, err);
 211         return err;
 212 }
 213 #endif
 214
 215 static void dbgp_disconnect(struct usb_gadget *gadget)
 216 {
 217 #ifdef CONFIG_USB_G_DBGP_PRINTK
 218         dbgp_disable_ep();
 219 #else
 220         gserial_disconnect(dbgp.serial);
 221 #endif
 222 }
 223
 224 static void dbgp_unbind(struct usb_gadget *gadget)
 225 {
 226 #ifdef CONFIG_USB_G_DBGP_SERIAL
 227         kfree(dbgp.serial);
 228 #endif
 229         if (dbgp.req) {
 230                 kfree(dbgp.req->buf);
 231                 usb_ep_free_request(gadget->ep0, dbgp.req);
 232         }
 233
 234         gadget->ep0->driver_data = NULL;
 235 }
 236
 237 static int __init dbgp_configure_endpoints(struct usb_gadget *gadget)
 238 {
 239         int stp;
 240
 241         usb_ep_autoconfig_reset(gadget);
 242
 243         dbgp.i_ep = usb_ep_autoconfig(gadget, &i_desc);
 244         if (!dbgp.i_ep) {
 245                 stp = 1;
 246                 goto fail_1;
 247         }
 248
 249         dbgp.i_ep->driver_data = gadget;
 250         i_desc.wMaxPacketSize =
 251                 __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE);
 252
 253         dbgp.o_ep = usb_ep_autoconfig(gadget, &o_desc);
 254         if (!dbgp.o_ep) {
 255                 dbgp.i_ep->driver_data = NULL;
 256                 stp = 2;
 257                 goto fail_2;
 258         }
 259
 260         dbgp.o_ep->driver_data = gadget;
 261         o_desc.wMaxPacketSize =
 262                 __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE);
 263
 264         dbg_desc.bDebugInEndpoint = i_desc.bEndpointAddress & 0x7f;
 265         dbg_desc.bDebugOutEndpoint = o_desc.bEndpointAddress & 0x7f;
 266
 267 #ifdef CONFIG_USB_G_DBGP_SERIAL
 268         dbgp.serial->in = dbgp.i_ep;
 269         dbgp.serial->out = dbgp.o_ep;
 270
 271         dbgp.serial->in_desc = &i_desc;
 272         dbgp.serial->out_desc = &o_desc;
 273
 274         if (gserial_setup(gadget, 1) < 0) {
 275                 stp = 3;
 276                 goto fail_3;
 277         }
 278
 279         return 0;
 280
 281 fail_3:
 282         dbgp.o_ep->driver_data = NULL;
 283 #else
 284         return 0;
 285 #endif
 286 fail_2:
 287         dbgp.i_ep->driver_data = NULL;
 288 fail_1:
 289         dev_dbg(&dbgp.gadget->dev, "ep config: failure (%d)\n", stp);
 290         return -ENODEV;
 291 }
 292
 293 static int __init dbgp_bind(struct usb_gadget *gadget)
 294 {
 295         int err, stp;
 296
 297         dbgp.gadget = gadget;
 298
 299         dbgp.req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
 300         if (!dbgp.req) {
 301                 err = -ENOMEM;
 302                 stp = 1;
 303                 goto fail;
 304         }
 305
 306         dbgp.req->buf = kmalloc(DBGP_REQ_EP0_LEN, GFP_KERNEL);
 307         if (!dbgp.req->buf) {
 308                 err = -ENOMEM;
 309                 stp = 2;
 310                 goto fail;
 311         }
 312
 313         dbgp.req->length = DBGP_REQ_EP0_LEN;
 314         gadget->ep0->driver_data = gadget;
 315
 316 #ifdef CONFIG_USB_G_DBGP_SERIAL
 317         dbgp.serial = kzalloc(sizeof(struct gserial), GFP_KERNEL);
 318         if (!dbgp.serial) {
 319                 stp = 3;
 320                 err = -ENOMEM;
 321                 goto fail;
 322         }
 323 #endif
 324         err = dbgp_configure_endpoints(gadget);
 325         if (err < 0) {
 326                 stp = 4;
 327                 goto fail;
 328         }
 329
 330         dev_dbg(&dbgp.gadget->dev, "bind: success\n");
 331         return 0;
 332
 333 fail:
 334         dev_dbg(&gadget->dev, "bind: failure (%d:%d)\n", stp, err);
 335         dbgp_unbind(gadget);
 336         return err;
 337 }
 338
 339 static void dbgp_setup_complete(struct usb_ep *ep,
 340                                 struct usb_request *req)
 341 {
 342         dev_dbg(&dbgp.gadget->dev, "setup complete: %d, %d/%d\n",
 343                 req->status, req->actual, req->length);
 344 }
 345
 346 static int dbgp_setup(struct usb_gadget *gadget,
 347                       const struct usb_ctrlrequest *ctrl)
 348 {
 349         struct usb_request *req = dbgp.req;
 350         u8 request = ctrl->bRequest;
 351         u16 value = le16_to_cpu(ctrl->wValue);
 352         u16 length = le16_to_cpu(ctrl->wLength);
 353         int err = 0;
 354         void *data;
 355         u16 len;
 356
 357         gadget->ep0->driver_data = gadget;
 358
 359         if (request == USB_REQ_GET_DESCRIPTOR) {
 360                 switch (value>>8) {
 361                 case USB_DT_DEVICE:
 362                         dev_dbg(&dbgp.gadget->dev, "setup: desc device\n");
 363                         len = sizeof device_desc;
 364                         data = &device_desc;
 365                         break;
 366                 case USB_DT_DEBUG:
 367                         dev_dbg(&dbgp.gadget->dev, "setup: desc debug\n");
 368                         len = sizeof dbg_desc;
 369                         data = &dbg_desc;
 370                         break;
 371                 default:
 372                         goto fail;
 373                 }
 374         } else if (request == USB_REQ_SET_FEATURE &&
 375                    value == USB_DEVICE_DEBUG_MODE) {
 376                 len = 0;
 377                 data = NULL;
 378                 dev_dbg(&dbgp.gadget->dev, "setup: feat debug\n");
 379 #ifdef CONFIG_USB_G_DBGP_PRINTK
 380                 err = dbgp_enable_ep();
 381 #else
 382                 err = gserial_connect(dbgp.serial, 0);
 383 #endif
 384                 if (err < 0)
 385                         goto fail;
 386         } else
 387                 goto fail;
 388
 389         if (len >= 0) {
 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
 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         .speed = USB_SPEED_HIGH,
 408         .bind = dbgp_bind,
 409         .unbind = dbgp_unbind,
 410         .setup = dbgp_setup,
 411         .disconnect = dbgp_disconnect,
 412         .driver = {
 413                 .owner = THIS_MODULE,
 414                 .name = "dbgp"
 415         },
 416 };
 417
 418 static int __init dbgp_init(void)
 419 {
 420         return usb_gadget_register_driver(&dbgp_driver);
 421 }
 422
 423 static void __exit dbgp_exit(void)
 424 {
 425         usb_gadget_unregister_driver(&dbgp_driver);
 426 #ifdef CONFIG_USB_G_DBGP_SERIAL
 427         gserial_cleanup();
 428 #endif
 429 }
 430
 431 MODULE_AUTHOR("Stephane Duverger");
 432 MODULE_LICENSE("GPL");
 433 module_init(dbgp_init);
 434 module_exit(dbgp_exit);