1 /* 2 * USB Serial Converter Generic functions 3 * 4 * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License version 8 * 2 as published by the Free Software Foundation. 9 * 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/errno.h> 14 #include <linux/slab.h> 15 #include <linux/tty.h> 16 #include <linux/tty_flip.h> 17 #include <linux/module.h> 18 #include <linux/moduleparam.h> 19 #include <linux/usb.h> 20 #include <linux/usb/serial.h> 21 #include <linux/uaccess.h> 22 23 24 static int debug; 25 26 #ifdef CONFIG_USB_SERIAL_GENERIC 27 28 static int generic_probe(struct usb_interface *interface, 29 const struct usb_device_id *id); 30 31 static __u16 vendor = 0x05f9; 32 static __u16 product = 0xffff; 33 34 module_param(vendor, ushort, 0); 35 MODULE_PARM_DESC(vendor, "User specified USB idVendor"); 36 37 module_param(product, ushort, 0); 38 MODULE_PARM_DESC(product, "User specified USB idProduct"); 39 40 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */ 41 42 /* we want to look at all devices, as the vendor/product id can change 43 * depending on the command line argument */ 44 static struct usb_device_id generic_serial_ids[] = { 45 {.driver_info = 42}, 46 {} 47 }; 48 49 static struct usb_driver generic_driver = { 50 .name = "usbserial_generic", 51 .probe = generic_probe, 52 .disconnect = usb_serial_disconnect, 53 .id_table = generic_serial_ids, 54 .no_dynamic_id = 1, 55 }; 56 57 /* All of the device info needed for the Generic Serial Converter */ 58 struct usb_serial_driver usb_serial_generic_device = { 59 .driver = { 60 .owner = THIS_MODULE, 61 .name = "generic", 62 }, 63 .id_table = generic_device_ids, 64 .usb_driver = &generic_driver, 65 .num_ports = 1, 66 .shutdown = usb_serial_generic_shutdown, 67 .throttle = usb_serial_generic_throttle, 68 .unthrottle = usb_serial_generic_unthrottle, 69 .resume = usb_serial_generic_resume, 70 }; 71 72 static int generic_probe(struct usb_interface *interface, 73 const struct usb_device_id *id) 74 { 75 const struct usb_device_id *id_pattern; 76 77 id_pattern = usb_match_id(interface, generic_device_ids); 78 if (id_pattern != NULL) 79 return usb_serial_probe(interface, id); 80 return -ENODEV; 81 } 82 #endif 83 84 int usb_serial_generic_register(int _debug) 85 { 86 int retval = 0; 87 88 debug = _debug; 89 #ifdef CONFIG_USB_SERIAL_GENERIC 90 generic_device_ids[0].idVendor = vendor; 91 generic_device_ids[0].idProduct = product; 92 generic_device_ids[0].match_flags = 93 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT; 94 95 /* register our generic driver with ourselves */ 96 retval = usb_serial_register(&usb_serial_generic_device); 97 if (retval) 98 goto exit; 99 retval = usb_register(&generic_driver); 100 if (retval) 101 usb_serial_deregister(&usb_serial_generic_device); 102 exit: 103 #endif 104 return retval; 105 } 106 107 void usb_serial_generic_deregister(void) 108 { 109 #ifdef CONFIG_USB_SERIAL_GENERIC 110 /* remove our generic driver */ 111 usb_deregister(&generic_driver); 112 usb_serial_deregister(&usb_serial_generic_device); 113 #endif 114 } 115 116 int usb_serial_generic_open(struct tty_struct *tty, 117 struct usb_serial_port *port, struct file *filp) 118 { 119 struct usb_serial *serial = port->serial; 120 int result = 0; 121 unsigned long flags; 122 123 dbg("%s - port %d", __func__, port->number); 124 125 /* force low_latency on so that our tty_push actually forces the data 126 through, otherwise it is scheduled, and with high data rates (like 127 with OHCI) data can get lost. */ 128 if (tty) 129 tty->low_latency = 1; 130 131 /* clear the throttle flags */ 132 spin_lock_irqsave(&port->lock, flags); 133 port->throttled = 0; 134 port->throttle_req = 0; 135 spin_unlock_irqrestore(&port->lock, flags); 136 137 /* if we have a bulk endpoint, start reading from it */ 138 if (serial->num_bulk_in) { 139 /* Start reading from the device */ 140 usb_fill_bulk_urb(port->read_urb, serial->dev, 141 usb_rcvbulkpipe(serial->dev, 142 port->bulk_in_endpointAddress), 143 port->read_urb->transfer_buffer, 144 port->read_urb->transfer_buffer_length, 145 ((serial->type->read_bulk_callback) ? 146 serial->type->read_bulk_callback : 147 usb_serial_generic_read_bulk_callback), 148 port); 149 result = usb_submit_urb(port->read_urb, GFP_KERNEL); 150 if (result) 151 dev_err(&port->dev, 152 "%s - failed resubmitting read urb, error %d\n", 153 __func__, result); 154 } 155 156 return result; 157 } 158 EXPORT_SYMBOL_GPL(usb_serial_generic_open); 159 160 static void generic_cleanup(struct usb_serial_port *port) 161 { 162 struct usb_serial *serial = port->serial; 163 164 dbg("%s - port %d", __func__, port->number); 165 166 if (serial->dev) { 167 /* shutdown any bulk reads that might be going on */ 168 if (serial->num_bulk_out) 169 usb_kill_urb(port->write_urb); 170 if (serial->num_bulk_in) 171 usb_kill_urb(port->read_urb); 172 } 173 } 174 175 int usb_serial_generic_resume(struct usb_serial *serial) 176 { 177 struct usb_serial_port *port; 178 int i, c = 0, r; 179 180 #ifdef CONFIG_PM 181 /* 182 * If this is an autoresume, don't submit URBs. 183 * They will be submitted in the open function instead. 184 */ 185 if (serial->dev->auto_pm) 186 return 0; 187 #endif 188 for (i = 0; i < serial->num_ports; i++) { 189 port = serial->port[i]; 190 if (port->port.count && port->read_urb) { 191 r = usb_submit_urb(port->read_urb, GFP_NOIO); 192 if (r < 0) 193 c++; 194 } 195 } 196 197 return c ? -EIO : 0; 198 } 199 200 void usb_serial_generic_close(struct tty_struct *tty, 201 struct usb_serial_port *port, struct file *filp) 202 { 203 dbg("%s - port %d", __func__, port->number); 204 generic_cleanup(port); 205 } 206 207 int usb_serial_generic_write(struct tty_struct *tty, 208 struct usb_serial_port *port, const unsigned char *buf, int count) 209 { 210 struct usb_serial *serial = port->serial; 211 int result; 212 unsigned char *data; 213 214 dbg("%s - port %d", __func__, port->number); 215 216 if (count == 0) { 217 dbg("%s - write request of 0 bytes", __func__); 218 return 0; 219 } 220 221 /* only do something if we have a bulk out endpoint */ 222 if (serial->num_bulk_out) { 223 unsigned long flags; 224 spin_lock_irqsave(&port->lock, flags); 225 if (port->write_urb_busy) { 226 spin_unlock_irqrestore(&port->lock, flags); 227 dbg("%s - already writing", __func__); 228 return 0; 229 } 230 port->write_urb_busy = 1; 231 spin_unlock_irqrestore(&port->lock, flags); 232 233 count = (count > port->bulk_out_size) ? 234 port->bulk_out_size : count; 235 236 memcpy(port->write_urb->transfer_buffer, buf, count); 237 data = port->write_urb->transfer_buffer; 238 usb_serial_debug_data(debug, &port->dev, __func__, count, data); 239 240 /* set up our urb */ 241 usb_fill_bulk_urb(port->write_urb, serial->dev, 242 usb_sndbulkpipe(serial->dev, 243 port->bulk_out_endpointAddress), 244 port->write_urb->transfer_buffer, count, 245 ((serial->type->write_bulk_callback) ? 246 serial->type->write_bulk_callback : 247 usb_serial_generic_write_bulk_callback), 248 port); 249 250 /* send the data out the bulk port */ 251 port->write_urb_busy = 1; 252 result = usb_submit_urb(port->write_urb, GFP_ATOMIC); 253 if (result) { 254 dev_err(&port->dev, 255 "%s - failed submitting write urb, error %d\n", 256 __func__, result); 257 /* don't have to grab the lock here, as we will 258 retry if != 0 */ 259 port->write_urb_busy = 0; 260 } else 261 result = count; 262 263 return result; 264 } 265 266 /* no bulk out, so return 0 bytes written */ 267 return 0; 268 } 269 270 int usb_serial_generic_write_room(struct tty_struct *tty) 271 { 272 struct usb_serial_port *port = tty->driver_data; 273 struct usb_serial *serial = port->serial; 274 int room = 0; 275 276 dbg("%s - port %d", __func__, port->number); 277 278 /* FIXME: Locking */ 279 if (serial->num_bulk_out) { 280 if (!(port->write_urb_busy)) 281 room = port->bulk_out_size; 282 } 283 284 dbg("%s - returns %d", __func__, room); 285 return room; 286 } 287 288 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty) 289 { 290 struct usb_serial_port *port = tty->driver_data; 291 struct usb_serial *serial = port->serial; 292 int chars = 0; 293 294 dbg("%s - port %d", __func__, port->number); 295 296 /* FIXME: Locking */ 297 if (serial->num_bulk_out) { 298 if (port->write_urb_busy) 299 chars = port->write_urb->transfer_buffer_length; 300 } 301 302 dbg("%s - returns %d", __func__, chars); 303 return chars; 304 } 305 306 307 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags) 308 { 309 struct urb *urb = port->read_urb; 310 struct usb_serial *serial = port->serial; 311 int result; 312 313 /* Continue reading from device */ 314 usb_fill_bulk_urb(urb, serial->dev, 315 usb_rcvbulkpipe(serial->dev, 316 port->bulk_in_endpointAddress), 317 urb->transfer_buffer, 318 urb->transfer_buffer_length, 319 ((serial->type->read_bulk_callback) ? 320 serial->type->read_bulk_callback : 321 usb_serial_generic_read_bulk_callback), port); 322 result = usb_submit_urb(urb, mem_flags); 323 if (result) 324 dev_err(&port->dev, 325 "%s - failed resubmitting read urb, error %d\n", 326 __func__, result); 327 } 328 329 /* Push data to tty layer and resubmit the bulk read URB */ 330 static void flush_and_resubmit_read_urb(struct usb_serial_port *port) 331 { 332 struct urb *urb = port->read_urb; 333 struct tty_struct *tty = port->port.tty; 334 int room; 335 336 /* Push data to tty */ 337 if (tty && urb->actual_length) { 338 room = tty_buffer_request_room(tty, urb->actual_length); 339 if (room) { 340 tty_insert_flip_string(tty, urb->transfer_buffer, room); 341 tty_flip_buffer_push(tty); 342 } 343 } 344 345 resubmit_read_urb(port, GFP_ATOMIC); 346 } 347 348 void usb_serial_generic_read_bulk_callback(struct urb *urb) 349 { 350 struct usb_serial_port *port = urb->context; 351 unsigned char *data = urb->transfer_buffer; 352 int status = urb->status; 353 unsigned long flags; 354 355 dbg("%s - port %d", __func__, port->number); 356 357 if (unlikely(status != 0)) { 358 dbg("%s - nonzero read bulk status received: %d", 359 __func__, status); 360 return; 361 } 362 363 usb_serial_debug_data(debug, &port->dev, __func__, 364 urb->actual_length, data); 365 366 /* Throttle the device if requested by tty */ 367 spin_lock_irqsave(&port->lock, flags); 368 port->throttled = port->throttle_req; 369 if (!port->throttled) { 370 spin_unlock_irqrestore(&port->lock, flags); 371 flush_and_resubmit_read_urb(port); 372 } else 373 spin_unlock_irqrestore(&port->lock, flags); 374 } 375 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); 376 377 void usb_serial_generic_write_bulk_callback(struct urb *urb) 378 { 379 struct usb_serial_port *port = urb->context; 380 int status = urb->status; 381 382 dbg("%s - port %d", __func__, port->number); 383 384 port->write_urb_busy = 0; 385 if (status) { 386 dbg("%s - nonzero write bulk status received: %d", 387 __func__, status); 388 return; 389 } 390 usb_serial_port_softint(port); 391 } 392 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); 393 394 void usb_serial_generic_throttle(struct tty_struct *tty) 395 { 396 struct usb_serial_port *port = tty->driver_data; 397 unsigned long flags; 398 399 dbg("%s - port %d", __func__, port->number); 400 401 /* Set the throttle request flag. It will be picked up 402 * by usb_serial_generic_read_bulk_callback(). */ 403 spin_lock_irqsave(&port->lock, flags); 404 port->throttle_req = 1; 405 spin_unlock_irqrestore(&port->lock, flags); 406 } 407 408 void usb_serial_generic_unthrottle(struct tty_struct *tty) 409 { 410 struct usb_serial_port *port = tty->driver_data; 411 int was_throttled; 412 unsigned long flags; 413 414 dbg("%s - port %d", __func__, port->number); 415 416 /* Clear the throttle flags */ 417 spin_lock_irqsave(&port->lock, flags); 418 was_throttled = port->throttled; 419 port->throttled = port->throttle_req = 0; 420 spin_unlock_irqrestore(&port->lock, flags); 421 422 if (was_throttled) { 423 /* Resume reading from device */ 424 resubmit_read_urb(port, GFP_KERNEL); 425 } 426 } 427 428 void usb_serial_generic_shutdown(struct usb_serial *serial) 429 { 430 int i; 431 432 dbg("%s", __func__); 433 434 /* stop reads and writes on all ports */ 435 for (i = 0; i < serial->num_ports; ++i) 436 generic_cleanup(serial->port[i]); 437 } 438 439