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 spin_lock_bh(&port->lock); 212 if (port->write_urb_busy) { 213 spin_unlock_bh(&port->lock); 214 dbg("%s - already writing", __FUNCTION__); 215 return 0; 216 } 217 port->write_urb_busy = 1; 218 spin_unlock_bh(&port->lock); 219 220 count = (count > port->bulk_out_size) ? port->bulk_out_size : count; 221 222 memcpy (port->write_urb->transfer_buffer, buf, count); 223 data = port->write_urb->transfer_buffer; 224 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data); 225 226 /* set up our urb */ 227 usb_fill_bulk_urb (port->write_urb, serial->dev, 228 usb_sndbulkpipe (serial->dev, 229 port->bulk_out_endpointAddress), 230 port->write_urb->transfer_buffer, count, 231 ((serial->type->write_bulk_callback) ? 232 serial->type->write_bulk_callback : 233 usb_serial_generic_write_bulk_callback), port); 234 235 /* send the data out the bulk port */ 236 port->write_urb_busy = 1; 237 result = usb_submit_urb(port->write_urb, GFP_ATOMIC); 238 if (result) { 239 dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result); 240 /* don't have to grab the lock here, as we will retry if != 0 */ 241 port->write_urb_busy = 0; 242 } else 243 result = count; 244 245 return result; 246 } 247 248 /* no bulk out, so return 0 bytes written */ 249 return 0; 250 } 251 252 int usb_serial_generic_write_room (struct usb_serial_port *port) 253 { 254 struct usb_serial *serial = port->serial; 255 int room = 0; 256 257 dbg("%s - port %d", __FUNCTION__, port->number); 258 259 if (serial->num_bulk_out) { 260 if (!(port->write_urb_busy)) 261 room = port->bulk_out_size; 262 } 263 264 dbg("%s - returns %d", __FUNCTION__, room); 265 return (room); 266 } 267 268 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port) 269 { 270 struct usb_serial *serial = port->serial; 271 int chars = 0; 272 273 dbg("%s - port %d", __FUNCTION__, port->number); 274 275 if (serial->num_bulk_out) { 276 if (port->write_urb_busy) 277 chars = port->write_urb->transfer_buffer_length; 278 } 279 280 dbg("%s - returns %d", __FUNCTION__, chars); 281 return (chars); 282 } 283 284 285 static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags) 286 { 287 struct urb *urb = port->read_urb; 288 struct usb_serial *serial = port->serial; 289 int result; 290 291 /* Continue reading from device */ 292 usb_fill_bulk_urb (urb, serial->dev, 293 usb_rcvbulkpipe (serial->dev, 294 port->bulk_in_endpointAddress), 295 urb->transfer_buffer, 296 urb->transfer_buffer_length, 297 ((serial->type->read_bulk_callback) ? 298 serial->type->read_bulk_callback : 299 usb_serial_generic_read_bulk_callback), port); 300 result = usb_submit_urb(urb, mem_flags); 301 if (result) 302 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result); 303 } 304 305 /* Push data to tty layer and resubmit the bulk read URB */ 306 static void flush_and_resubmit_read_urb (struct usb_serial_port *port) 307 { 308 struct urb *urb = port->read_urb; 309 struct tty_struct *tty = port->tty; 310 int room; 311 312 /* Push data to tty */ 313 if (tty && urb->actual_length) { 314 room = tty_buffer_request_room(tty, urb->actual_length); 315 if (room) { 316 tty_insert_flip_string(tty, urb->transfer_buffer, room); 317 tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */ 318 } 319 } 320 321 resubmit_read_urb(port, GFP_ATOMIC); 322 } 323 324 void usb_serial_generic_read_bulk_callback (struct urb *urb) 325 { 326 struct usb_serial_port *port = (struct usb_serial_port *)urb->context; 327 unsigned char *data = urb->transfer_buffer; 328 int status = urb->status; 329 330 dbg("%s - port %d", __FUNCTION__, port->number); 331 332 if (unlikely(status != 0)) { 333 dbg("%s - nonzero read bulk status received: %d", 334 __FUNCTION__, status); 335 return; 336 } 337 338 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data); 339 340 /* Throttle the device if requested by tty */ 341 spin_lock(&port->lock); 342 if (!(port->throttled = port->throttle_req)) 343 /* Handle data and continue reading from device */ 344 flush_and_resubmit_read_urb(port); 345 spin_unlock(&port->lock); 346 } 347 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); 348 349 void usb_serial_generic_write_bulk_callback (struct urb *urb) 350 { 351 struct usb_serial_port *port = (struct usb_serial_port *)urb->context; 352 int status = urb->status; 353 354 dbg("%s - port %d", __FUNCTION__, port->number); 355 356 port->write_urb_busy = 0; 357 if (status) { 358 dbg("%s - nonzero write bulk status received: %d", 359 __FUNCTION__, status); 360 return; 361 } 362 363 usb_serial_port_softint(port); 364 } 365 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); 366 367 void usb_serial_generic_throttle (struct usb_serial_port *port) 368 { 369 unsigned long flags; 370 371 dbg("%s - port %d", __FUNCTION__, port->number); 372 373 /* Set the throttle request flag. It will be picked up 374 * by usb_serial_generic_read_bulk_callback(). */ 375 spin_lock_irqsave(&port->lock, flags); 376 port->throttle_req = 1; 377 spin_unlock_irqrestore(&port->lock, flags); 378 } 379 380 void usb_serial_generic_unthrottle (struct usb_serial_port *port) 381 { 382 int was_throttled; 383 unsigned long flags; 384 385 dbg("%s - port %d", __FUNCTION__, port->number); 386 387 /* Clear the throttle flags */ 388 spin_lock_irqsave(&port->lock, flags); 389 was_throttled = port->throttled; 390 port->throttled = port->throttle_req = 0; 391 spin_unlock_irqrestore(&port->lock, flags); 392 393 if (was_throttled) { 394 /* Resume reading from device */ 395 resubmit_read_urb(port, GFP_KERNEL); 396 } 397 } 398 399 void usb_serial_generic_shutdown (struct usb_serial *serial) 400 { 401 int i; 402 403 dbg("%s", __FUNCTION__); 404 405 /* stop reads and writes on all ports */ 406 for (i=0; i < serial->num_ports; ++i) { 407 generic_cleanup(serial->port[i]); 408 } 409 } 410 411