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 <asm/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_interrupt_in = NUM_DONT_CARE, 66 .num_bulk_in = NUM_DONT_CARE, 67 .num_bulk_out = NUM_DONT_CARE, 68 .num_ports = 1, 69 .shutdown = usb_serial_generic_shutdown, 70 .throttle = usb_serial_generic_throttle, 71 .unthrottle = usb_serial_generic_unthrottle, 72 .resume = usb_serial_generic_resume, 73 }; 74 75 static int generic_probe(struct usb_interface *interface, 76 const struct usb_device_id *id) 77 { 78 const struct usb_device_id *id_pattern; 79 80 id_pattern = usb_match_id(interface, generic_device_ids); 81 if (id_pattern != NULL) 82 return usb_serial_probe(interface, id); 83 return -ENODEV; 84 } 85 #endif 86 87 int usb_serial_generic_register (int _debug) 88 { 89 int retval = 0; 90 91 debug = _debug; 92 #ifdef CONFIG_USB_SERIAL_GENERIC 93 generic_device_ids[0].idVendor = vendor; 94 generic_device_ids[0].idProduct = product; 95 generic_device_ids[0].match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT; 96 97 /* register our generic driver with ourselves */ 98 retval = usb_serial_register (&usb_serial_generic_device); 99 if (retval) 100 goto exit; 101 retval = usb_register(&generic_driver); 102 if (retval) 103 usb_serial_deregister(&usb_serial_generic_device); 104 exit: 105 #endif 106 return retval; 107 } 108 109 void usb_serial_generic_deregister (void) 110 { 111 #ifdef CONFIG_USB_SERIAL_GENERIC 112 /* remove our generic driver */ 113 usb_deregister(&generic_driver); 114 usb_serial_deregister (&usb_serial_generic_device); 115 #endif 116 } 117 118 int usb_serial_generic_open (struct usb_serial_port *port, struct file *filp) 119 { 120 struct usb_serial *serial = port->serial; 121 int result = 0; 122 unsigned long flags; 123 124 dbg("%s - port %d", __FUNCTION__, port->number); 125 126 /* force low_latency on so that our tty_push actually forces the data through, 127 otherwise it is scheduled, and with high data rates (like with OHCI) data 128 can get lost. */ 129 if (port->tty) 130 port->tty->low_latency = 1; 131 132 /* clear the throttle flags */ 133 spin_lock_irqsave(&port->lock, flags); 134 port->throttled = 0; 135 port->throttle_req = 0; 136 spin_unlock_irqrestore(&port->lock, flags); 137 138 /* if we have a bulk endpoint, start reading from it */ 139 if (serial->num_bulk_in) { 140 /* Start reading from the device */ 141 usb_fill_bulk_urb (port->read_urb, serial->dev, 142 usb_rcvbulkpipe(serial->dev, 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, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result); 152 } 153 154 return result; 155 } 156 EXPORT_SYMBOL_GPL(usb_serial_generic_open); 157 158 static void generic_cleanup (struct usb_serial_port *port) 159 { 160 struct usb_serial *serial = port->serial; 161 162 dbg("%s - port %d", __FUNCTION__, port->number); 163 164 if (serial->dev) { 165 /* shutdown any bulk reads that might be going on */ 166 if (serial->num_bulk_out) 167 usb_kill_urb(port->write_urb); 168 if (serial->num_bulk_in) 169 usb_kill_urb(port->read_urb); 170 } 171 } 172 173 int usb_serial_generic_resume(struct usb_serial *serial) 174 { 175 struct usb_serial_port *port; 176 int i, c = 0, r; 177 178 #ifdef CONFIG_PM 179 /* 180 * If this is an autoresume, don't submit URBs. 181 * They will be submitted in the open function instead. 182 */ 183 if (serial->dev->auto_pm) 184 return 0; 185 #endif 186 for (i = 0; i < serial->num_ports; i++) { 187 port = serial->port[i]; 188 if (port->open_count && port->read_urb) { 189 r = usb_submit_urb(port->read_urb, GFP_NOIO); 190 if (r < 0) 191 c++; 192 } 193 } 194 195 return c ? -EIO : 0; 196 } 197 198 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp) 199 { 200 dbg("%s - port %d", __FUNCTION__, port->number); 201 generic_cleanup (port); 202 } 203 204 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count) 205 { 206 struct usb_serial *serial = port->serial; 207 int result; 208 unsigned char *data; 209 210 dbg("%s - port %d", __FUNCTION__, port->number); 211 212 if (count == 0) { 213 dbg("%s - write request of 0 bytes", __FUNCTION__); 214 return (0); 215 } 216 217 /* only do something if we have a bulk out endpoint */ 218 if (serial->num_bulk_out) { 219 unsigned long flags; 220 spin_lock_irqsave(&port->lock, flags); 221 if (port->write_urb_busy) { 222 spin_unlock_irqrestore(&port->lock, flags); 223 dbg("%s - already writing", __FUNCTION__); 224 return 0; 225 } 226 port->write_urb_busy = 1; 227 spin_unlock_irqrestore(&port->lock, flags); 228 229 count = (count > port->bulk_out_size) ? port->bulk_out_size : count; 230 231 memcpy (port->write_urb->transfer_buffer, buf, count); 232 data = port->write_urb->transfer_buffer; 233 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data); 234 235 /* set up our urb */ 236 usb_fill_bulk_urb (port->write_urb, serial->dev, 237 usb_sndbulkpipe (serial->dev, 238 port->bulk_out_endpointAddress), 239 port->write_urb->transfer_buffer, count, 240 ((serial->type->write_bulk_callback) ? 241 serial->type->write_bulk_callback : 242 usb_serial_generic_write_bulk_callback), port); 243 244 /* send the data out the bulk port */ 245 port->write_urb_busy = 1; 246 result = usb_submit_urb(port->write_urb, GFP_ATOMIC); 247 if (result) { 248 dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result); 249 /* don't have to grab the lock here, as we will retry if != 0 */ 250 port->write_urb_busy = 0; 251 } else 252 result = count; 253 254 return result; 255 } 256 257 /* no bulk out, so return 0 bytes written */ 258 return 0; 259 } 260 261 int usb_serial_generic_write_room (struct usb_serial_port *port) 262 { 263 struct usb_serial *serial = port->serial; 264 int room = 0; 265 266 dbg("%s - port %d", __FUNCTION__, port->number); 267 268 if (serial->num_bulk_out) { 269 if (!(port->write_urb_busy)) 270 room = port->bulk_out_size; 271 } 272 273 dbg("%s - returns %d", __FUNCTION__, room); 274 return (room); 275 } 276 277 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port) 278 { 279 struct usb_serial *serial = port->serial; 280 int chars = 0; 281 282 dbg("%s - port %d", __FUNCTION__, port->number); 283 284 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", __FUNCTION__, 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, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result); 312 } 313 314 /* Push data to tty layer and resubmit the bulk read URB */ 315 static void flush_and_resubmit_read_urb (struct usb_serial_port *port) 316 { 317 struct urb *urb = port->read_urb; 318 struct tty_struct *tty = port->tty; 319 int room; 320 321 /* Push data to tty */ 322 if (tty && urb->actual_length) { 323 room = tty_buffer_request_room(tty, urb->actual_length); 324 if (room) { 325 tty_insert_flip_string(tty, urb->transfer_buffer, room); 326 tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */ 327 } 328 } 329 330 resubmit_read_urb(port, GFP_ATOMIC); 331 } 332 333 void usb_serial_generic_read_bulk_callback (struct urb *urb) 334 { 335 struct usb_serial_port *port = (struct usb_serial_port *)urb->context; 336 unsigned char *data = urb->transfer_buffer; 337 int status = urb->status; 338 unsigned long flags; 339 340 dbg("%s - port %d", __FUNCTION__, port->number); 341 342 if (unlikely(status != 0)) { 343 dbg("%s - nonzero read bulk status received: %d", 344 __FUNCTION__, status); 345 return; 346 } 347 348 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data); 349 350 /* Throttle the device if requested by tty */ 351 spin_lock_irqsave(&port->lock, flags); 352 if (!(port->throttled = port->throttle_req)) 353 /* Handle data and continue reading from device */ 354 flush_and_resubmit_read_urb(port); 355 spin_unlock_irqrestore(&port->lock, flags); 356 } 357 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); 358 359 void usb_serial_generic_write_bulk_callback (struct urb *urb) 360 { 361 struct usb_serial_port *port = (struct usb_serial_port *)urb->context; 362 int status = urb->status; 363 364 dbg("%s - port %d", __FUNCTION__, port->number); 365 366 port->write_urb_busy = 0; 367 if (status) { 368 dbg("%s - nonzero write bulk status received: %d", 369 __FUNCTION__, status); 370 return; 371 } 372 373 usb_serial_port_softint(port); 374 } 375 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); 376 377 void usb_serial_generic_throttle (struct usb_serial_port *port) 378 { 379 unsigned long flags; 380 381 dbg("%s - port %d", __FUNCTION__, port->number); 382 383 /* Set the throttle request flag. It will be picked up 384 * by usb_serial_generic_read_bulk_callback(). */ 385 spin_lock_irqsave(&port->lock, flags); 386 port->throttle_req = 1; 387 spin_unlock_irqrestore(&port->lock, flags); 388 } 389 390 void usb_serial_generic_unthrottle (struct usb_serial_port *port) 391 { 392 int was_throttled; 393 unsigned long flags; 394 395 dbg("%s - port %d", __FUNCTION__, port->number); 396 397 /* Clear the throttle flags */ 398 spin_lock_irqsave(&port->lock, flags); 399 was_throttled = port->throttled; 400 port->throttled = port->throttle_req = 0; 401 spin_unlock_irqrestore(&port->lock, flags); 402 403 if (was_throttled) { 404 /* Resume reading from device */ 405 resubmit_read_urb(port, GFP_KERNEL); 406 } 407 } 408 409 void usb_serial_generic_shutdown (struct usb_serial *serial) 410 { 411 int i; 412 413 dbg("%s", __FUNCTION__); 414 415 /* stop reads and writes on all ports */ 416 for (i=0; i < serial->num_ports; ++i) { 417 generic_cleanup(serial->port[i]); 418 } 419 } 420 421