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 /* clear the throttle flags */ 126 spin_lock_irqsave(&port->lock, flags); 127 port->throttled = 0; 128 port->throttle_req = 0; 129 spin_unlock_irqrestore(&port->lock, flags); 130 131 /* if we have a bulk endpoint, start reading from it */ 132 if (serial->num_bulk_in) { 133 /* Start reading from the device */ 134 usb_fill_bulk_urb(port->read_urb, serial->dev, 135 usb_rcvbulkpipe(serial->dev, 136 port->bulk_in_endpointAddress), 137 port->read_urb->transfer_buffer, 138 port->read_urb->transfer_buffer_length, 139 ((serial->type->read_bulk_callback) ? 140 serial->type->read_bulk_callback : 141 usb_serial_generic_read_bulk_callback), 142 port); 143 result = usb_submit_urb(port->read_urb, GFP_KERNEL); 144 if (result) 145 dev_err(&port->dev, 146 "%s - failed resubmitting read urb, error %d\n", 147 __func__, result); 148 } 149 150 return result; 151 } 152 EXPORT_SYMBOL_GPL(usb_serial_generic_open); 153 154 static void generic_cleanup(struct usb_serial_port *port) 155 { 156 struct usb_serial *serial = port->serial; 157 158 dbg("%s - port %d", __func__, port->number); 159 160 if (serial->dev) { 161 /* shutdown any bulk reads that might be going on */ 162 if (serial->num_bulk_out) 163 usb_kill_urb(port->write_urb); 164 if (serial->num_bulk_in) 165 usb_kill_urb(port->read_urb); 166 } 167 } 168 169 int usb_serial_generic_resume(struct usb_serial *serial) 170 { 171 struct usb_serial_port *port; 172 int i, c = 0, r; 173 174 for (i = 0; i < serial->num_ports; i++) { 175 port = serial->port[i]; 176 if (port->port.count && port->read_urb) { 177 r = usb_submit_urb(port->read_urb, GFP_NOIO); 178 if (r < 0) 179 c++; 180 } 181 } 182 183 return c ? -EIO : 0; 184 } 185 EXPORT_SYMBOL_GPL(usb_serial_generic_resume); 186 187 void usb_serial_generic_close(struct tty_struct *tty, 188 struct usb_serial_port *port, struct file *filp) 189 { 190 dbg("%s - port %d", __func__, port->number); 191 generic_cleanup(port); 192 } 193 194 int usb_serial_generic_write(struct tty_struct *tty, 195 struct usb_serial_port *port, const unsigned char *buf, int count) 196 { 197 struct usb_serial *serial = port->serial; 198 int result; 199 unsigned char *data; 200 201 dbg("%s - port %d", __func__, port->number); 202 203 if (count == 0) { 204 dbg("%s - write request of 0 bytes", __func__); 205 return 0; 206 } 207 208 /* only do something if we have a bulk out endpoint */ 209 if (serial->num_bulk_out) { 210 unsigned long flags; 211 spin_lock_irqsave(&port->lock, flags); 212 if (port->write_urb_busy) { 213 spin_unlock_irqrestore(&port->lock, flags); 214 dbg("%s - already writing", __func__); 215 return 0; 216 } 217 port->write_urb_busy = 1; 218 spin_unlock_irqrestore(&port->lock, flags); 219 220 count = (count > port->bulk_out_size) ? 221 port->bulk_out_size : count; 222 223 memcpy(port->write_urb->transfer_buffer, buf, count); 224 data = port->write_urb->transfer_buffer; 225 usb_serial_debug_data(debug, &port->dev, __func__, count, data); 226 227 /* set up our urb */ 228 usb_fill_bulk_urb(port->write_urb, serial->dev, 229 usb_sndbulkpipe(serial->dev, 230 port->bulk_out_endpointAddress), 231 port->write_urb->transfer_buffer, count, 232 ((serial->type->write_bulk_callback) ? 233 serial->type->write_bulk_callback : 234 usb_serial_generic_write_bulk_callback), 235 port); 236 237 /* send the data out the bulk port */ 238 port->write_urb_busy = 1; 239 result = usb_submit_urb(port->write_urb, GFP_ATOMIC); 240 if (result) { 241 dev_err(&port->dev, 242 "%s - failed submitting write urb, error %d\n", 243 __func__, result); 244 /* don't have to grab the lock here, as we will 245 retry if != 0 */ 246 port->write_urb_busy = 0; 247 } else 248 result = count; 249 250 return result; 251 } 252 253 /* no bulk out, so return 0 bytes written */ 254 return 0; 255 } 256 257 int usb_serial_generic_write_room(struct tty_struct *tty) 258 { 259 struct usb_serial_port *port = tty->driver_data; 260 struct usb_serial *serial = port->serial; 261 int room = 0; 262 263 dbg("%s - port %d", __func__, port->number); 264 265 /* FIXME: Locking */ 266 if (serial->num_bulk_out) { 267 if (!(port->write_urb_busy)) 268 room = port->bulk_out_size; 269 } 270 271 dbg("%s - returns %d", __func__, room); 272 return room; 273 } 274 275 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty) 276 { 277 struct usb_serial_port *port = tty->driver_data; 278 struct usb_serial *serial = port->serial; 279 int chars = 0; 280 281 dbg("%s - port %d", __func__, port->number); 282 283 /* FIXME: Locking */ 284 if (serial->num_bulk_out) { 285 if (port->write_urb_busy) 286 chars = port->write_urb->transfer_buffer_length; 287 } 288 289 dbg("%s - returns %d", __func__, chars); 290 return chars; 291 } 292 293 294 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags) 295 { 296 struct urb *urb = port->read_urb; 297 struct usb_serial *serial = port->serial; 298 int result; 299 300 /* Continue reading from device */ 301 usb_fill_bulk_urb(urb, serial->dev, 302 usb_rcvbulkpipe(serial->dev, 303 port->bulk_in_endpointAddress), 304 urb->transfer_buffer, 305 urb->transfer_buffer_length, 306 ((serial->type->read_bulk_callback) ? 307 serial->type->read_bulk_callback : 308 usb_serial_generic_read_bulk_callback), port); 309 result = usb_submit_urb(urb, mem_flags); 310 if (result) 311 dev_err(&port->dev, 312 "%s - failed resubmitting read urb, error %d\n", 313 __func__, result); 314 } 315 316 /* Push data to tty layer and resubmit the bulk read URB */ 317 static void flush_and_resubmit_read_urb(struct usb_serial_port *port) 318 { 319 struct urb *urb = port->read_urb; 320 struct tty_struct *tty = tty_port_tty_get(&port->port); 321 int room; 322 323 /* Push data to tty */ 324 if (tty && urb->actual_length) { 325 room = tty_buffer_request_room(tty, urb->actual_length); 326 if (room) { 327 tty_insert_flip_string(tty, urb->transfer_buffer, room); 328 tty_flip_buffer_push(tty); 329 } 330 } 331 tty_kref_put(tty); 332 333 resubmit_read_urb(port, GFP_ATOMIC); 334 } 335 336 void usb_serial_generic_read_bulk_callback(struct urb *urb) 337 { 338 struct usb_serial_port *port = urb->context; 339 unsigned char *data = urb->transfer_buffer; 340 int status = urb->status; 341 unsigned long flags; 342 343 dbg("%s - port %d", __func__, port->number); 344 345 if (unlikely(status != 0)) { 346 dbg("%s - nonzero read bulk status received: %d", 347 __func__, status); 348 return; 349 } 350 351 usb_serial_debug_data(debug, &port->dev, __func__, 352 urb->actual_length, data); 353 354 /* Throttle the device if requested by tty */ 355 spin_lock_irqsave(&port->lock, flags); 356 port->throttled = port->throttle_req; 357 if (!port->throttled) { 358 spin_unlock_irqrestore(&port->lock, flags); 359 flush_and_resubmit_read_urb(port); 360 } else 361 spin_unlock_irqrestore(&port->lock, flags); 362 } 363 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); 364 365 void usb_serial_generic_write_bulk_callback(struct urb *urb) 366 { 367 struct usb_serial_port *port = urb->context; 368 int status = urb->status; 369 370 dbg("%s - port %d", __func__, port->number); 371 372 port->write_urb_busy = 0; 373 if (status) { 374 dbg("%s - nonzero write bulk status received: %d", 375 __func__, status); 376 return; 377 } 378 usb_serial_port_softint(port); 379 } 380 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); 381 382 void usb_serial_generic_throttle(struct tty_struct *tty) 383 { 384 struct usb_serial_port *port = tty->driver_data; 385 unsigned long flags; 386 387 dbg("%s - port %d", __func__, port->number); 388 389 /* Set the throttle request flag. It will be picked up 390 * by usb_serial_generic_read_bulk_callback(). */ 391 spin_lock_irqsave(&port->lock, flags); 392 port->throttle_req = 1; 393 spin_unlock_irqrestore(&port->lock, flags); 394 } 395 396 void usb_serial_generic_unthrottle(struct tty_struct *tty) 397 { 398 struct usb_serial_port *port = tty->driver_data; 399 int was_throttled; 400 unsigned long flags; 401 402 dbg("%s - port %d", __func__, port->number); 403 404 /* Clear the throttle flags */ 405 spin_lock_irqsave(&port->lock, flags); 406 was_throttled = port->throttled; 407 port->throttled = port->throttle_req = 0; 408 spin_unlock_irqrestore(&port->lock, flags); 409 410 if (was_throttled) { 411 /* Resume reading from device */ 412 resubmit_read_urb(port, GFP_KERNEL); 413 } 414 } 415 416 void usb_serial_generic_shutdown(struct usb_serial *serial) 417 { 418 int i; 419 420 dbg("%s", __func__); 421 422 /* stop reads and writes on all ports */ 423 for (i = 0; i < serial->num_ports; ++i) 424 generic_cleanup(serial->port[i]); 425 } 426 427