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 #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 = __constant_cpu_to_le16(0x0200),
  39         .bDeviceClass = USB_CLASS_VENDOR_SPEC,
  40         .idVendor = __constant_cpu_to_le16(DRIVER_VENDOR_ID),
  41         .idProduct = __constant_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         if (ep && ep->driver_data == dbgp.gadget) {
  83                 usb_ep_disable(ep);
  84                 ep->driver_data = NULL;
  85         }
  86 }
  87
  88 static void dbgp_disable_ep(void)
  89 {
  90         __disable_ep(dbgp.i_ep);
  91         __disable_ep(dbgp.o_ep);
  92 }
  93
  94 static void dbgp_complete(struct usb_ep *ep, struct usb_request *req)
  95 {
  96         int stp;
  97         int err = 0;
  98         int status = req->status;
  99
 100         if (ep == dbgp.i_ep) {
 101                 stp = 1;
 102                 goto fail;
 103         }
 104
 105         if (status != 0) {
 106                 stp = 2;
 107                 goto release_req;
 108         }
 109
 110         dbgp_consume(req->buf, req->actual);
 111
 112         req->length = DBGP_REQ_LEN;
 113         err = usb_ep_queue(ep, req, GFP_ATOMIC);
 114         if (err < 0) {
 115                 stp = 3;
 116                 goto release_req;
 117         }
 118
 119         return;
 120
 121 release_req:
 122         kfree(req->buf);
 123         usb_ep_free_request(dbgp.o_ep, req);
 124         dbgp_disable_ep();
 125 fail:
 126         dev_dbg(&dbgp.gadget->dev,
 127                 "complete: failure (%d:%d) ==> %d\n", stp, err, status);
 128 }
 129
 130 static int dbgp_enable_ep_req(struct usb_ep *ep)
 131 {
 132         int err, stp;
 133         struct usb_request *req;
 134
 135         req = usb_ep_alloc_request(ep, GFP_KERNEL);
 136         if (!req) {
 137                 err = -ENOMEM;
 138                 stp = 1;
 139                 goto fail_1;
 140         }
 141
 142         req->buf = kmalloc(DBGP_REQ_LEN, GFP_KERNEL);
 143         if (!req->buf) {
 144                 err = -ENOMEM;
 145                 stp = 2;
 146                 goto fail_2;
 147         }
 148
 149         req->complete = dbgp_complete;
 150         req->length = DBGP_REQ_LEN;
 151         err = usb_ep_queue(ep, req, GFP_ATOMIC);
 152         if (err < 0) {
 153                 stp = 3;
 154                 goto fail_3;
 155         }
 156
 157         return 0;
 158
 159 fail_3:
 160         kfree(req->buf);
 161 fail_2:
 162         usb_ep_free_request(dbgp.o_ep, req);
 163 fail_1:
 164         dev_dbg(&dbgp.gadget->dev,
 165                 "enable ep req: failure (%d:%d)\n", stp, err);
 166         return err;
 167 }
 168
 169 static int __enable_ep(struct usb_ep *ep, struct usb_endpoint_descriptor *desc)
 170 {
 171         int err;
 172         ep->desc = desc;
 173         err = usb_ep_enable(ep);
 174         ep->driver_data = dbgp.gadget;
 175         return err;
 176 }
 177
 178 static int dbgp_enable_ep(void)
 179 {
 180         int err, stp;
 181
 182         err = __enable_ep(dbgp.i_ep, &i_desc);
 183         if (err < 0) {
 184                 stp = 1;
 185                 goto fail_1;
 186         }
 187
 188         err = __enable_ep(dbgp.o_ep, &o_desc);
 189         if (err < 0) {
 190                 stp = 2;
 191                 goto fail_2;
 192         }
 193
 194         err = dbgp_enable_ep_req(dbgp.o_ep);
 195         if (err < 0) {
 196                 stp = 3;
 197                 goto fail_3;
 198         }
 199
 200         return 0;
 201
 202 fail_3:
 203         __disable_ep(dbgp.o_ep);
 204 fail_2:
 205         __disable_ep(dbgp.i_ep);
 206 fail_1:
 207         dev_dbg(&dbgp.gadget->dev, "enable ep: failure (%d:%d)\n", stp, err);
 208         return err;
 209 }
 210 #endif
 211
 212 static void dbgp_disconnect(struct usb_gadget *gadget)
 213 {
 214 #ifdef CONFIG_USB_G_DBGP_PRINTK
 215         dbgp_disable_ep();
 216 #else
 217         gserial_disconnect(dbgp.serial);
 218 #endif
 219 }
 220
 221 static void dbgp_unbind(struct usb_gadget *gadget)
 222 {
 223 #ifdef CONFIG_USB_G_DBGP_SERIAL
 224         kfree(dbgp.serial);
 225 #endif
 226         if (dbgp.req) {
 227                 kfree(dbgp.req->buf);
 228                 usb_ep_free_request(gadget->ep0, dbgp.req);
 229         }
 230
 231         gadget->ep0->driver_data = NULL;
 232 }
 233
 234 #ifdef CONFIG_USB_G_DBGP_SERIAL
 235 static unsigned char tty_line;
 236 #endif
 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_alloc_line(&tty_line)) {
 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                 struct usb_gadget_driver *driver)
 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, tty_line);
 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 __refdata struct usb_gadget_driver dbgp_driver = {
 406         .function = "dbgp",
 407         .max_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_probe_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_free_line(tty_line);
 428 #endif
 429 }
 430
 431 MODULE_AUTHOR("Stephane Duverger");
 432 MODULE_LICENSE("GPL");
 433 module_init(dbgp_init);
 434 module_exit(dbgp_exit);