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 = __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         dbgp.serial = NULL;
 226 #endif
 227         if (dbgp.req) {
 228                 kfree(dbgp.req->buf);
 229                 usb_ep_free_request(gadget->ep0, dbgp.req);
 230                 dbgp.req = NULL;
 231         }
 232
 233         gadget->ep0->driver_data = NULL;
 234 }
 235
 236 #ifdef CONFIG_USB_G_DBGP_SERIAL
 237 static unsigned char tty_line;
 238 #endif
 239
 240 static int __init dbgp_configure_endpoints(struct usb_gadget *gadget)
 241 {
 242         int stp;
 243
 244         usb_ep_autoconfig_reset(gadget);
 245
 246         dbgp.i_ep = usb_ep_autoconfig(gadget, &i_desc);
 247         if (!dbgp.i_ep) {
 248                 stp = 1;
 249                 goto fail_1;
 250         }
 251
 252         dbgp.i_ep->driver_data = gadget;
 253         i_desc.wMaxPacketSize =
 254                 __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE);
 255
 256         dbgp.o_ep = usb_ep_autoconfig(gadget, &o_desc);
 257         if (!dbgp.o_ep) {
 258                 dbgp.i_ep->driver_data = NULL;
 259                 stp = 2;
 260                 goto fail_2;
 261         }
 262
 263         dbgp.o_ep->driver_data = gadget;
 264         o_desc.wMaxPacketSize =
 265                 __constant_cpu_to_le16(USB_DEBUG_MAX_PACKET_SIZE);
 266
 267         dbg_desc.bDebugInEndpoint = i_desc.bEndpointAddress;
 268         dbg_desc.bDebugOutEndpoint = o_desc.bEndpointAddress;
 269
 270 #ifdef CONFIG_USB_G_DBGP_SERIAL
 271         dbgp.serial->in = dbgp.i_ep;
 272         dbgp.serial->out = dbgp.o_ep;
 273
 274         dbgp.serial->in->desc = &i_desc;
 275         dbgp.serial->out->desc = &o_desc;
 276
 277         if (gserial_alloc_line(&tty_line)) {
 278                 stp = 3;
 279                 goto fail_3;
 280         }
 281
 282         return 0;
 283
 284 fail_3:
 285         dbgp.o_ep->driver_data = NULL;
 286 #else
 287         return 0;
 288 #endif
 289 fail_2:
 290         dbgp.i_ep->driver_data = NULL;
 291 fail_1:
 292         dev_dbg(&dbgp.gadget->dev, "ep config: failure (%d)\n", stp);
 293         return -ENODEV;
 294 }
 295
 296 static int __init dbgp_bind(struct usb_gadget *gadget,
 297                 struct usb_gadget_driver *driver)
 298 {
 299         int err, stp;
 300
 301         dbgp.gadget = gadget;
 302
 303         dbgp.req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
 304         if (!dbgp.req) {
 305                 err = -ENOMEM;
 306                 stp = 1;
 307                 goto fail;
 308         }
 309
 310         dbgp.req->buf = kmalloc(DBGP_REQ_EP0_LEN, GFP_KERNEL);
 311         if (!dbgp.req->buf) {
 312                 err = -ENOMEM;
 313                 stp = 2;
 314                 goto fail;
 315         }
 316
 317         dbgp.req->length = DBGP_REQ_EP0_LEN;
 318         gadget->ep0->driver_data = gadget;
 319
 320 #ifdef CONFIG_USB_G_DBGP_SERIAL
 321         dbgp.serial = kzalloc(sizeof(struct gserial), GFP_KERNEL);
 322         if (!dbgp.serial) {
 323                 stp = 3;
 324                 err = -ENOMEM;
 325                 goto fail;
 326         }
 327 #endif
 328         err = dbgp_configure_endpoints(gadget);
 329         if (err < 0) {
 330                 stp = 4;
 331                 goto fail;
 332         }
 333
 334         dev_dbg(&dbgp.gadget->dev, "bind: success\n");
 335         return 0;
 336
 337 fail:
 338         dev_dbg(&gadget->dev, "bind: failure (%d:%d)\n", stp, err);
 339         dbgp_unbind(gadget);
 340         return err;
 341 }
 342
 343 static void dbgp_setup_complete(struct usb_ep *ep,
 344                                 struct usb_request *req)
 345 {
 346         dev_dbg(&dbgp.gadget->dev, "setup complete: %d, %d/%d\n",
 347                 req->status, req->actual, req->length);
 348 }
 349
 350 static int dbgp_setup(struct usb_gadget *gadget,
 351                       const struct usb_ctrlrequest *ctrl)
 352 {
 353         struct usb_request *req = dbgp.req;
 354         u8 request = ctrl->bRequest;
 355         u16 value = le16_to_cpu(ctrl->wValue);
 356         u16 length = le16_to_cpu(ctrl->wLength);
 357         int err = -EOPNOTSUPP;
 358         void *data = NULL;
 359         u16 len = 0;
 360
 361         gadget->ep0->driver_data = gadget;
 362
 363         if (request == USB_REQ_GET_DESCRIPTOR) {
 364                 switch (value>>8) {
 365                 case USB_DT_DEVICE:
 366                         dev_dbg(&dbgp.gadget->dev, "setup: desc device\n");
 367                         len = sizeof device_desc;
 368                         data = &device_desc;
 369                         device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
 370                         break;
 371                 case USB_DT_DEBUG:
 372                         dev_dbg(&dbgp.gadget->dev, "setup: desc debug\n");
 373                         len = sizeof dbg_desc;
 374                         data = &dbg_desc;
 375                         break;
 376                 default:
 377                         goto fail;
 378                 }
 379                 err = 0;
 380         } else if (request == USB_REQ_SET_FEATURE &&
 381                    value == USB_DEVICE_DEBUG_MODE) {
 382                 dev_dbg(&dbgp.gadget->dev, "setup: feat debug\n");
 383 #ifdef CONFIG_USB_G_DBGP_PRINTK
 384                 err = dbgp_enable_ep();
 385 #else
 386                 err = gserial_connect(dbgp.serial, tty_line);
 387 #endif
 388                 if (err < 0)
 389                         goto fail;
 390         } else
 391                 goto fail;
 392
 393         req->length = min(length, len);
 394         req->zero = len < req->length;
 395         if (data && req->length)
 396                 memcpy(req->buf, data, req->length);
 397
 398         req->complete = dbgp_setup_complete;
 399         return usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
 400
 401 fail:
 402         dev_dbg(&dbgp.gadget->dev,
 403                 "setup: failure req %x v %x\n", request, value);
 404         return err;
 405 }
 406
 407 static __refdata struct usb_gadget_driver dbgp_driver = {
 408         .function = "dbgp",
 409         .max_speed = USB_SPEED_HIGH,
 410         .bind = dbgp_bind,
 411         .unbind = dbgp_unbind,
 412         .setup = dbgp_setup,
 413         .reset = dbgp_disconnect,
 414         .disconnect = dbgp_disconnect,
 415         .driver = {
 416                 .owner = THIS_MODULE,
 417                 .name = "dbgp"
 418         },
 419 };
 420
 421 static int __init dbgp_init(void)
 422 {
 423         return usb_gadget_probe_driver(&dbgp_driver);
 424 }
 425
 426 static void __exit dbgp_exit(void)
 427 {
 428         usb_gadget_unregister_driver(&dbgp_driver);
 429 #ifdef CONFIG_USB_G_DBGP_SERIAL
 430         gserial_free_line(tty_line);
 431 #endif
 432 }
 433
 434 MODULE_AUTHOR("Stephane Duverger");
 435 MODULE_LICENSE("GPL");
 436 module_init(dbgp_init);
 437 module_exit(dbgp_exit);