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 #ifdef CONFIG_USB_G_DBGP_SERIAL
  17 #include "u_serial.c"
  18 #endif
  19
  20 #define DRIVER_VENDOR_ID        0x0525 /* NetChip */
  21 #define DRIVER_PRODUCT_ID       0xc0de /* undefined */
  22
  23 #define USB_DEBUG_MAX_PACKET_SIZE     8
  24 #define DBGP_REQ_EP0_LEN              128
  25 #define DBGP_REQ_LEN                  512
  26
  27 static struct dbgp {
  28         struct usb_gadget  *gadget;
  29         struct usb_request *req;
  30         struct usb_ep      *i_ep;
  31         struct usb_ep      *o_ep;
  32 #ifdef CONFIG_USB_G_DBGP_SERIAL
  33         struct gserial     *serial;
  34 #endif
  35 } dbgp;
  36
  37 static struct usb_device_descriptor device_desc = {
  38         .bLength = sizeof device_desc,
  39         .bDescriptorType = USB_DT_DEVICE,
  40         .bcdUSB = __constant_cpu_to_le16(0x0200),
  41         .bDeviceClass = USB_CLASS_VENDOR_SPEC,
  42         .idVendor = __constant_cpu_to_le16(DRIVER_VENDOR_ID),
  43         .idProduct = __constant_cpu_to_le16(DRIVER_PRODUCT_ID),
  44         .bNumConfigurations = 1,
  45 };
  46
  47 static struct usb_debug_descriptor dbg_desc = {
  48         .bLength = sizeof dbg_desc,
  49         .bDescriptorType = USB_DT_DEBUG,
  50 };
  51
  52 static struct usb_endpoint_descriptor i_desc = {
  53         .bLength = USB_DT_ENDPOINT_SIZE,
  54         .bDescriptorType = USB_DT_ENDPOINT,
  55         .bmAttributes = USB_ENDPOINT_XFER_BULK,
  56         .bEndpointAddress = USB_DIR_IN,
  57 };
  58
  59 static struct usb_endpoint_descriptor o_desc = {
  60         .bLength = USB_DT_ENDPOINT_SIZE,
  61         .bDescriptorType = USB_DT_ENDPOINT,
  62         .bmAttributes = USB_ENDPOINT_XFER_BULK,
  63         .bEndpointAddress = USB_DIR_OUT,
  64 };
  65
  66 #ifdef CONFIG_USB_G_DBGP_PRINTK
  67 static int dbgp_consume(char *buf, unsigned len)
  68 {
  69         char c;
  70
  71         if (!len)
  72                 return 0;
  73
  74         c = buf[len-1];
  75         if (c != 0)
  76                 buf[len-1] = 0;
  77
  78         printk(KERN_NOTICE "%s%c", buf, c);
  79         return 0;
  80 }
  81
  82 static void __disable_ep(struct usb_ep *ep)
  83 {
  84         if (ep && ep->driver_data == dbgp.gadget) {
  85                 usb_ep_disable(ep);
  86                 ep->driver_data = NULL;
  87         }
  88 }
  89
  90 static void dbgp_disable_ep(void)
  91 {
  92         __disable_ep(dbgp.i_ep);
  93         __disable_ep(dbgp.o_ep);
  94 }
  95
  96 static void dbgp_complete(struct usb_ep *ep, struct usb_request *req)
  97 {
  98         int stp;
  99         int err = 0;
 100         int status = req->status;
 101
 102         if (ep == dbgp.i_ep) {
 103                 stp = 1;
 104                 goto fail;
 105         }
 106
 107         if (status != 0) {
 108                 stp = 2;
 109                 goto release_req;
 110         }
 111
 112         dbgp_consume(req->buf, req->actual);
 113
 114         req->length = DBGP_REQ_LEN;
 115         err = usb_ep_queue(ep, req, GFP_ATOMIC);
 116         if (err < 0) {
 117                 stp = 3;
 118                 goto release_req;
 119         }
 120
 121         return;
 122
 123 release_req:
 124         kfree(req->buf);
 125         usb_ep_free_request(dbgp.o_ep, req);
 126         dbgp_disable_ep();
 127 fail:
 128         dev_dbg(&dbgp.gadget->dev,
 129                 "complete: failure (%d:%d) ==> %d\n", stp, err, status);
 130 }
 131
 132 static int dbgp_enable_ep_req(struct usb_ep *ep)
 133 {
 134         int err, stp;
 135         struct usb_request *req;
 136
 137         req = usb_ep_alloc_request(ep, GFP_KERNEL);
 138         if (!req) {
 139                 err = -ENOMEM;
 140                 stp = 1;
 141                 goto fail_1;
 142         }
 143
 144         req->buf = kmalloc(DBGP_REQ_LEN, GFP_KERNEL);
 145         if (!req->buf) {
 146                 err = -ENOMEM;
 147                 stp = 2;
 148                 goto fail_2;
 149         }
 150
 151         req->complete = dbgp_complete;
 152         req->length = DBGP_REQ_LEN;
 153         err = usb_ep_queue(ep, req, GFP_ATOMIC);
 154         if (err < 0) {
 155                 stp = 3;
 156                 goto fail_3;
 157         }
 158
 159         return 0;
 160
 161 fail_3:
 162         kfree(req->buf);
 163 fail_2:
 164         usb_ep_free_request(dbgp.o_ep, req);
 165 fail_1:
 166         dev_dbg(&dbgp.gadget->dev,
 167                 "enable ep req: failure (%d:%d)\n", stp, err);
 168         return err;
 169 }
 170
 171 static int __enable_ep(struct usb_ep *ep, struct usb_endpoint_descriptor *desc)
 172 {
 173         int err;
 174         ep->desc = desc;
 175         err = usb_ep_enable(ep);
 176         ep->driver_data = dbgp.gadget;
 177         return err;
 178 }
 179
 180 static int dbgp_enable_ep(void)
 181 {
 182         int err, stp;
 183
 184         err = __enable_ep(dbgp.i_ep, &i_desc);
 185         if (err < 0) {
 186                 stp = 1;
 187                 goto fail_1;
 188         }
 189
 190         err = __enable_ep(dbgp.o_ep, &o_desc);
 191         if (err < 0) {
 192                 stp = 2;
 193                 goto fail_2;
 194         }
 195
 196         err = dbgp_enable_ep_req(dbgp.o_ep);
 197         if (err < 0) {
 198                 stp = 3;
 199                 goto fail_3;
 200         }
 201
 202         return 0;
 203
 204 fail_3:
 205         __disable_ep(dbgp.o_ep);
 206 fail_2:
 207         __disable_ep(dbgp.i_ep);
 208 fail_1:
 209         dev_dbg(&dbgp.gadget->dev, "enable ep: failure (%d:%d)\n", stp, err);
 210         return err;
 211 }
 212 #endif
 213
 214 static void dbgp_disconnect(struct usb_gadget *gadget)
 215 {
 216 #ifdef CONFIG_USB_G_DBGP_PRINTK
 217         dbgp_disable_ep();
 218 #else
 219         gserial_disconnect(dbgp.serial);
 220 #endif
 221 }
 222
 223 static void dbgp_unbind(struct usb_gadget *gadget)
 224 {
 225 #ifdef CONFIG_USB_G_DBGP_SERIAL
 226         kfree(dbgp.serial);
 227 #endif
 228         if (dbgp.req) {
 229                 kfree(dbgp.req->buf);
 230                 usb_ep_free_request(gadget->ep0, dbgp.req);
 231         }
 232
 233         gadget->ep0->driver_data = NULL;
 234 }
 235
 236 static int __init dbgp_configure_endpoints(struct usb_gadget *gadget)
 237 {
 238         int stp;
 239
 240         usb_ep_autoconfig_reset(gadget);
 241
 242         dbgp.i_ep = usb_ep_autoconfig(gadget, &i_desc);
 243         if (!dbgp.i_ep) {
 244                 stp = 1;
 245                 goto fail_1;
 246         }
 247
 248         dbgp.i_ep->driver_data = gadget;
 249         i_desc.wMaxPacketSize =
 250                 __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE);
 251
 252         dbgp.o_ep = usb_ep_autoconfig(gadget, &o_desc);
 253         if (!dbgp.o_ep) {
 254                 dbgp.i_ep->driver_data = NULL;
 255                 stp = 2;
 256                 goto fail_2;
 257         }
 258
 259         dbgp.o_ep->driver_data = gadget;
 260         o_desc.wMaxPacketSize =
 261                 __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE);
 262
 263         dbg_desc.bDebugInEndpoint = i_desc.bEndpointAddress;
 264         dbg_desc.bDebugOutEndpoint = o_desc.bEndpointAddress;
 265
 266 #ifdef CONFIG_USB_G_DBGP_SERIAL
 267         dbgp.serial->in = dbgp.i_ep;
 268         dbgp.serial->out = dbgp.o_ep;
 269
 270         dbgp.serial->in->desc = &i_desc;
 271         dbgp.serial->out->desc = &o_desc;
 272
 273         if (gserial_setup(gadget, 1) < 0) {
 274                 stp = 3;
 275                 goto fail_3;
 276         }
 277
 278         return 0;
 279
 280 fail_3:
 281         dbgp.o_ep->driver_data = NULL;
 282 #else
 283         return 0;
 284 #endif
 285 fail_2:
 286         dbgp.i_ep->driver_data = NULL;
 287 fail_1:
 288         dev_dbg(&dbgp.gadget->dev, "ep config: failure (%d)\n", stp);
 289         return -ENODEV;
 290 }
 291
 292 static int __init dbgp_bind(struct usb_gadget *gadget,
 293                 struct usb_gadget_driver *driver)
 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 = -EOPNOTSUPP;
 354         void *data = NULL;
 355         u16 len = 0;
 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                         device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
 366                         break;
 367                 case USB_DT_DEBUG:
 368                         dev_dbg(&dbgp.gadget->dev, "setup: desc debug\n");
 369                         len = sizeof dbg_desc;
 370                         data = &dbg_desc;
 371                         break;
 372                 default:
 373                         goto fail;
 374                 }
 375                 err = 0;
 376         } else if (request == USB_REQ_SET_FEATURE &&
 377                    value == USB_DEVICE_DEBUG_MODE) {
 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         req->length = min(length, len);
 390         req->zero = len < req->length;
 391         if (data && req->length)
 392                 memcpy(req->buf, data, req->length);
 393
 394         req->complete = dbgp_setup_complete;
 395         return usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
 396
 397 fail:
 398         dev_dbg(&dbgp.gadget->dev,
 399                 "setup: failure req %x v %x\n", request, value);
 400         return err;
 401 }
 402
 403 static __refdata struct usb_gadget_driver dbgp_driver = {
 404         .function = "dbgp",
 405         .max_speed = USB_SPEED_HIGH,
 406         .bind = dbgp_bind,
 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);
 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);