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 static int generic_probe(struct usb_interface *interface, 24 const struct usb_device_id *id); 25 26 27 static int debug; 28 29 #ifdef CONFIG_USB_SERIAL_GENERIC 30 static __u16 vendor = 0x05f9; 31 static __u16 product = 0xffff; 32 33 module_param(vendor, ushort, 0); 34 MODULE_PARM_DESC(vendor, "User specified USB idVendor"); 35 36 module_param(product, ushort, 0); 37 MODULE_PARM_DESC(product, "User specified USB idProduct"); 38 39 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */ 40 41 /* we want to look at all devices, as the vendor/product id can change 42 * depending on the command line argument */ 43 static struct usb_device_id generic_serial_ids[] = { 44 {.driver_info = 42}, 45 {} 46 }; 47 48 static struct usb_driver generic_driver = { 49 .name = "usbserial_generic", 50 .probe = generic_probe, 51 .disconnect = usb_serial_disconnect, 52 .id_table = generic_serial_ids, 53 .no_dynamic_id = 1, 54 }; 55 56 /* All of the device info needed for the Generic Serial Converter */ 57 struct usb_serial_driver usb_serial_generic_device = { 58 .driver = { 59 .owner = THIS_MODULE, 60 .name = "generic", 61 }, 62 .id_table = generic_device_ids, 63 .usb_driver = &generic_driver, 64 .num_interrupt_in = NUM_DONT_CARE, 65 .num_bulk_in = NUM_DONT_CARE, 66 .num_bulk_out = NUM_DONT_CARE, 67 .num_ports = 1, 68 .shutdown = usb_serial_generic_shutdown, 69 .throttle = usb_serial_generic_throttle, 70 .unthrottle = usb_serial_generic_unthrottle, 71 }; 72 73 static int generic_probe(struct usb_interface *interface, 74 const struct usb_device_id *id) 75 { 76 const struct usb_device_id *id_pattern; 77 78 id_pattern = usb_match_id(interface, generic_device_ids); 79 if (id_pattern != NULL) 80 return usb_serial_probe(interface, id); 81 return -ENODEV; 82 } 83 #endif 84 85 int usb_serial_generic_register (int _debug) 86 { 87 int retval = 0; 88 89 debug = _debug; 90 #ifdef CONFIG_USB_SERIAL_GENERIC 91 generic_device_ids[0].idVendor = vendor; 92 generic_device_ids[0].idProduct = product; 93 generic_device_ids[0].match_flags = 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 usb_serial_port *port, struct file *filp) 117 { 118 struct usb_serial *serial = port->serial; 119 int result = 0; 120 unsigned long flags; 121 122 dbg("%s - port %d", __FUNCTION__, port->number); 123 124 /* force low_latency on so that our tty_push actually forces the data through, 125 otherwise it is scheduled, and with high data rates (like with OHCI) data 126 can get lost. */ 127 if (port->tty) 128 port->tty->low_latency = 1; 129 130 /* clear the throttle flags */ 131 spin_lock_irqsave(&port->lock, flags); 132 port->throttled = 0; 133 port->throttle_req = 0; 134 spin_unlock_irqrestore(&port->lock, flags); 135 136 /* if we have a bulk endpoint, start reading from it */ 137 if (serial->num_bulk_in) { 138 /* Start reading from the device */ 139 usb_fill_bulk_urb (port->read_urb, serial->dev, 140 usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress), 141 port->read_urb->transfer_buffer, 142 port->read_urb->transfer_buffer_length, 143 ((serial->type->read_bulk_callback) ? 144 serial->type->read_bulk_callback : 145 usb_serial_generic_read_bulk_callback), 146 port); 147 result = usb_submit_urb(port->read_urb, GFP_KERNEL); 148 if (result) 149 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result); 150 } 151 152 return result; 153 } 154 EXPORT_SYMBOL_GPL(usb_serial_generic_open); 155 156 static void generic_cleanup (struct usb_serial_port *port) 157 { 158 struct usb_serial *serial = port->serial; 159 160 dbg("%s - port %d", __FUNCTION__, port->number); 161 162 if (serial->dev) { 163 /* shutdown any bulk reads that might be going on */ 164 if (serial->num_bulk_out) 165 usb_kill_urb(port->write_urb); 166 if (serial->num_bulk_in) 167 usb_kill_urb(port->read_urb); 168 } 169 } 170 171 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp) 172 { 173 dbg("%s - port %d", __FUNCTION__, port->number); 174 generic_cleanup (port); 175 } 176 177 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count) 178 { 179 struct usb_serial *serial = port->serial; 180 int result; 181 unsigned char *data; 182 183 dbg("%s - port %d", __FUNCTION__, port->number); 184 185 if (count == 0) { 186 dbg("%s - write request of 0 bytes", __FUNCTION__); 187 return (0); 188 } 189 190 /* only do something if we have a bulk out endpoint */ 191 if (serial->num_bulk_out) { 192 spin_lock_bh(&port->lock); 193 if (port->write_urb_busy) { 194 spin_unlock_bh(&port->lock); 195 dbg("%s - already writing", __FUNCTION__); 196 return 0; 197 } 198 port->write_urb_busy = 1; 199 spin_unlock_bh(&port->lock); 200 201 count = (count > port->bulk_out_size) ? port->bulk_out_size : count; 202 203 memcpy (port->write_urb->transfer_buffer, buf, count); 204 data = port->write_urb->transfer_buffer; 205 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data); 206 207 /* set up our urb */ 208 usb_fill_bulk_urb (port->write_urb, serial->dev, 209 usb_sndbulkpipe (serial->dev, 210 port->bulk_out_endpointAddress), 211 port->write_urb->transfer_buffer, count, 212 ((serial->type->write_bulk_callback) ? 213 serial->type->write_bulk_callback : 214 usb_serial_generic_write_bulk_callback), port); 215 216 /* send the data out the bulk port */ 217 port->write_urb_busy = 1; 218 result = usb_submit_urb(port->write_urb, GFP_ATOMIC); 219 if (result) { 220 dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result); 221 /* don't have to grab the lock here, as we will retry if != 0 */ 222 port->write_urb_busy = 0; 223 } else 224 result = count; 225 226 return result; 227 } 228 229 /* no bulk out, so return 0 bytes written */ 230 return 0; 231 } 232 233 int usb_serial_generic_write_room (struct usb_serial_port *port) 234 { 235 struct usb_serial *serial = port->serial; 236 int room = 0; 237 238 dbg("%s - port %d", __FUNCTION__, port->number); 239 240 if (serial->num_bulk_out) { 241 if (!(port->write_urb_busy)) 242 room = port->bulk_out_size; 243 } 244 245 dbg("%s - returns %d", __FUNCTION__, room); 246 return (room); 247 } 248 249 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port) 250 { 251 struct usb_serial *serial = port->serial; 252 int chars = 0; 253 254 dbg("%s - port %d", __FUNCTION__, port->number); 255 256 if (serial->num_bulk_out) { 257 if (port->write_urb_busy) 258 chars = port->write_urb->transfer_buffer_length; 259 } 260 261 dbg("%s - returns %d", __FUNCTION__, chars); 262 return (chars); 263 } 264 265 /* Push data to tty layer and resubmit the bulk read URB */ 266 static void flush_and_resubmit_read_urb (struct usb_serial_port *port) 267 { 268 struct usb_serial *serial = port->serial; 269 struct urb *urb = port->read_urb; 270 struct tty_struct *tty = port->tty; 271 int result; 272 273 /* Push data to tty */ 274 if (tty && urb->actual_length) { 275 tty_buffer_request_room(tty, urb->actual_length); 276 tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length); 277 tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */ 278 } 279 280 /* Continue reading from device */ 281 usb_fill_bulk_urb (port->read_urb, serial->dev, 282 usb_rcvbulkpipe (serial->dev, 283 port->bulk_in_endpointAddress), 284 port->read_urb->transfer_buffer, 285 port->read_urb->transfer_buffer_length, 286 ((serial->type->read_bulk_callback) ? 287 serial->type->read_bulk_callback : 288 usb_serial_generic_read_bulk_callback), port); 289 result = usb_submit_urb(port->read_urb, GFP_ATOMIC); 290 if (result) 291 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result); 292 } 293 294 void usb_serial_generic_read_bulk_callback (struct urb *urb) 295 { 296 struct usb_serial_port *port = (struct usb_serial_port *)urb->context; 297 unsigned char *data = urb->transfer_buffer; 298 int is_throttled; 299 unsigned long flags; 300 301 dbg("%s - port %d", __FUNCTION__, port->number); 302 303 if (urb->status) { 304 dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status); 305 return; 306 } 307 308 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data); 309 310 /* Throttle the device if requested by tty */ 311 if (urb->actual_length) { 312 spin_lock_irqsave(&port->lock, flags); 313 is_throttled = port->throttled = port->throttle_req; 314 spin_unlock_irqrestore(&port->lock, flags); 315 if (is_throttled) { 316 /* Let the received data linger in the read URB; 317 * usb_serial_generic_unthrottle() will pick it 318 * up later. */ 319 dbg("%s - throttling device", __FUNCTION__); 320 return; 321 } 322 } 323 324 /* Handle data and continue reading from device */ 325 flush_and_resubmit_read_urb(port); 326 } 327 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); 328 329 void usb_serial_generic_write_bulk_callback (struct urb *urb) 330 { 331 struct usb_serial_port *port = (struct usb_serial_port *)urb->context; 332 333 dbg("%s - port %d", __FUNCTION__, port->number); 334 335 port->write_urb_busy = 0; 336 if (urb->status) { 337 dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status); 338 return; 339 } 340 341 usb_serial_port_softint(port); 342 } 343 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); 344 345 void usb_serial_generic_throttle (struct usb_serial_port *port) 346 { 347 unsigned long flags; 348 349 dbg("%s - port %d", __FUNCTION__, port->number); 350 351 /* Set the throttle request flag. It will be picked up 352 * by usb_serial_generic_read_bulk_callback(). */ 353 spin_lock_irqsave(&port->lock, flags); 354 port->throttle_req = 1; 355 spin_unlock_irqrestore(&port->lock, flags); 356 } 357 358 void usb_serial_generic_unthrottle (struct usb_serial_port *port) 359 { 360 int was_throttled; 361 unsigned long flags; 362 363 dbg("%s - port %d", __FUNCTION__, port->number); 364 365 /* Clear the throttle flags */ 366 spin_lock_irqsave(&port->lock, flags); 367 was_throttled = port->throttled; 368 port->throttled = port->throttle_req = 0; 369 spin_unlock_irqrestore(&port->lock, flags); 370 371 if (was_throttled) { 372 /* Handle pending data and resume reading from device */ 373 flush_and_resubmit_read_urb(port); 374 } 375 } 376 377 void usb_serial_generic_shutdown (struct usb_serial *serial) 378 { 379 int i; 380 381 dbg("%s", __FUNCTION__); 382 383 /* stop reads and writes on all ports */ 384 for (i=0; i < serial->num_ports; ++i) { 385 generic_cleanup(serial->port[i]); 386 } 387 } 388 389