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 for (i = 0; i < serial->num_ports; i++) { 179 port = serial->port[i]; 180 if (port->open_count && port->read_urb) { 181 r = usb_submit_urb(port->read_urb, GFP_NOIO); 182 if (r < 0) 183 c++; 184 } 185 } 186 187 return c ? -EIO : 0; 188 } 189 190 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp) 191 { 192 dbg("%s - port %d", __FUNCTION__, port->number); 193 generic_cleanup (port); 194 } 195 196 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count) 197 { 198 struct usb_serial *serial = port->serial; 199 int result; 200 unsigned char *data; 201 202 dbg("%s - port %d", __FUNCTION__, port->number); 203 204 if (count == 0) { 205 dbg("%s - write request of 0 bytes", __FUNCTION__); 206 return (0); 207 } 208 209 /* only do something if we have a bulk out endpoint */ 210 if (serial->num_bulk_out) { 211 unsigned long flags; 212 spin_lock_irqsave(&port->lock, flags); 213 if (port->write_urb_busy) { 214 spin_unlock_irqrestore(&port->lock, flags); 215 dbg("%s - already writing", __FUNCTION__); 216 return 0; 217 } 218 port->write_urb_busy = 1; 219 spin_unlock_irqrestore(&port->lock, flags); 220 221 count = (count > port->bulk_out_size) ? 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, __FUNCTION__, 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), port); 235 236 /* send the data out the bulk port */ 237 port->write_urb_busy = 1; 238 result = usb_submit_urb(port->write_urb, GFP_ATOMIC); 239 if (result) { 240 dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result); 241 /* don't have to grab the lock here, as we will retry if != 0 */ 242 port->write_urb_busy = 0; 243 } else 244 result = count; 245 246 return result; 247 } 248 249 /* no bulk out, so return 0 bytes written */ 250 return 0; 251 } 252 253 int usb_serial_generic_write_room (struct usb_serial_port *port) 254 { 255 struct usb_serial *serial = port->serial; 256 int room = 0; 257 258 dbg("%s - port %d", __FUNCTION__, port->number); 259 260 if (serial->num_bulk_out) { 261 if (!(port->write_urb_busy)) 262 room = port->bulk_out_size; 263 } 264 265 dbg("%s - returns %d", __FUNCTION__, room); 266 return (room); 267 } 268 269 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port) 270 { 271 struct usb_serial *serial = port->serial; 272 int chars = 0; 273 274 dbg("%s - port %d", __FUNCTION__, port->number); 275 276 if (serial->num_bulk_out) { 277 if (port->write_urb_busy) 278 chars = port->write_urb->transfer_buffer_length; 279 } 280 281 dbg("%s - returns %d", __FUNCTION__, chars); 282 return (chars); 283 } 284 285 286 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags) 287 { 288 struct urb *urb = port->read_urb; 289 struct usb_serial *serial = port->serial; 290 int result; 291 292 /* Continue reading from device */ 293 usb_fill_bulk_urb (urb, serial->dev, 294 usb_rcvbulkpipe (serial->dev, 295 port->bulk_in_endpointAddress), 296 urb->transfer_buffer, 297 urb->transfer_buffer_length, 298 ((serial->type->read_bulk_callback) ? 299 serial->type->read_bulk_callback : 300 usb_serial_generic_read_bulk_callback), port); 301 result = usb_submit_urb(urb, mem_flags); 302 if (result) 303 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result); 304 } 305 306 /* Push data to tty layer and resubmit the bulk read URB */ 307 static void flush_and_resubmit_read_urb (struct usb_serial_port *port) 308 { 309 struct urb *urb = port->read_urb; 310 struct tty_struct *tty = port->tty; 311 int room; 312 313 /* Push data to tty */ 314 if (tty && urb->actual_length) { 315 room = tty_buffer_request_room(tty, urb->actual_length); 316 if (room) { 317 tty_insert_flip_string(tty, urb->transfer_buffer, room); 318 tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */ 319 } 320 } 321 322 resubmit_read_urb(port, GFP_ATOMIC); 323 } 324 325 void usb_serial_generic_read_bulk_callback (struct urb *urb) 326 { 327 struct usb_serial_port *port = (struct usb_serial_port *)urb->context; 328 unsigned char *data = urb->transfer_buffer; 329 int status = urb->status; 330 331 dbg("%s - port %d", __FUNCTION__, port->number); 332 333 if (unlikely(status != 0)) { 334 dbg("%s - nonzero read bulk status received: %d", 335 __FUNCTION__, status); 336 return; 337 } 338 339 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data); 340 341 /* Throttle the device if requested by tty */ 342 spin_lock(&port->lock); 343 if (!(port->throttled = port->throttle_req)) 344 /* Handle data and continue reading from device */ 345 flush_and_resubmit_read_urb(port); 346 spin_unlock(&port->lock); 347 } 348 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); 349 350 void usb_serial_generic_write_bulk_callback (struct urb *urb) 351 { 352 struct usb_serial_port *port = (struct usb_serial_port *)urb->context; 353 int status = urb->status; 354 355 dbg("%s - port %d", __FUNCTION__, port->number); 356 357 port->write_urb_busy = 0; 358 if (status) { 359 dbg("%s - nonzero write bulk status received: %d", 360 __FUNCTION__, status); 361 return; 362 } 363 364 usb_serial_port_softint(port); 365 } 366 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); 367 368 void usb_serial_generic_throttle (struct usb_serial_port *port) 369 { 370 unsigned long flags; 371 372 dbg("%s - port %d", __FUNCTION__, port->number); 373 374 /* Set the throttle request flag. It will be picked up 375 * by usb_serial_generic_read_bulk_callback(). */ 376 spin_lock_irqsave(&port->lock, flags); 377 port->throttle_req = 1; 378 spin_unlock_irqrestore(&port->lock, flags); 379 } 380 381 void usb_serial_generic_unthrottle (struct usb_serial_port *port) 382 { 383 int was_throttled; 384 unsigned long flags; 385 386 dbg("%s - port %d", __FUNCTION__, port->number); 387 388 /* Clear the throttle flags */ 389 spin_lock_irqsave(&port->lock, flags); 390 was_throttled = port->throttled; 391 port->throttled = port->throttle_req = 0; 392 spin_unlock_irqrestore(&port->lock, flags); 393 394 if (was_throttled) { 395 /* Resume reading from device */ 396 resubmit_read_urb(port, GFP_KERNEL); 397 } 398 } 399 400 void usb_serial_generic_shutdown (struct usb_serial *serial) 401 { 402 int i; 403 404 dbg("%s", __FUNCTION__); 405 406 /* stop reads and writes on all ports */ 407 for (i=0; i < serial->num_ports; ++i) { 408 generic_cleanup(serial->port[i]); 409 } 410 } 411 412