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 }; 73 74 static int generic_probe(struct usb_interface *interface, 75 const struct usb_device_id *id) 76 { 77 const struct usb_device_id *id_pattern; 78 79 id_pattern = usb_match_id(interface, generic_device_ids); 80 if (id_pattern != NULL) 81 return usb_serial_probe(interface, id); 82 return -ENODEV; 83 } 84 #endif 85 86 int usb_serial_generic_register (int _debug) 87 { 88 int retval = 0; 89 90 debug = _debug; 91 #ifdef CONFIG_USB_SERIAL_GENERIC 92 generic_device_ids[0].idVendor = vendor; 93 generic_device_ids[0].idProduct = product; 94 generic_device_ids[0].match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT; 95 96 /* register our generic driver with ourselves */ 97 retval = usb_serial_register (&usb_serial_generic_device); 98 if (retval) 99 goto exit; 100 retval = usb_register(&generic_driver); 101 if (retval) 102 usb_serial_deregister(&usb_serial_generic_device); 103 exit: 104 #endif 105 return retval; 106 } 107 108 void usb_serial_generic_deregister (void) 109 { 110 #ifdef CONFIG_USB_SERIAL_GENERIC 111 /* remove our generic driver */ 112 usb_deregister(&generic_driver); 113 usb_serial_deregister (&usb_serial_generic_device); 114 #endif 115 } 116 117 int usb_serial_generic_open (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", __FUNCTION__, port->number); 124 125 /* force low_latency on so that our tty_push actually forces the data through, 126 otherwise it is scheduled, and with high data rates (like with OHCI) data 127 can get lost. */ 128 if (port->tty) 129 port->tty->low_latency = 1; 130 131 /* clear the throttle flags */ 132 spin_lock_irqsave(&port->lock, flags); 133 port->throttled = 0; 134 port->throttle_req = 0; 135 spin_unlock_irqrestore(&port->lock, flags); 136 137 /* if we have a bulk endpoint, start reading from it */ 138 if (serial->num_bulk_in) { 139 /* Start reading from the device */ 140 usb_fill_bulk_urb (port->read_urb, serial->dev, 141 usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress), 142 port->read_urb->transfer_buffer, 143 port->read_urb->transfer_buffer_length, 144 ((serial->type->read_bulk_callback) ? 145 serial->type->read_bulk_callback : 146 usb_serial_generic_read_bulk_callback), 147 port); 148 result = usb_submit_urb(port->read_urb, GFP_KERNEL); 149 if (result) 150 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result); 151 } 152 153 return result; 154 } 155 EXPORT_SYMBOL_GPL(usb_serial_generic_open); 156 157 static void generic_cleanup (struct usb_serial_port *port) 158 { 159 struct usb_serial *serial = port->serial; 160 161 dbg("%s - port %d", __FUNCTION__, port->number); 162 163 if (serial->dev) { 164 /* shutdown any bulk reads that might be going on */ 165 if (serial->num_bulk_out) 166 usb_kill_urb(port->write_urb); 167 if (serial->num_bulk_in) 168 usb_kill_urb(port->read_urb); 169 } 170 } 171 172 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp) 173 { 174 dbg("%s - port %d", __FUNCTION__, port->number); 175 generic_cleanup (port); 176 } 177 178 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count) 179 { 180 struct usb_serial *serial = port->serial; 181 int result; 182 unsigned char *data; 183 184 dbg("%s - port %d", __FUNCTION__, port->number); 185 186 if (count == 0) { 187 dbg("%s - write request of 0 bytes", __FUNCTION__); 188 return (0); 189 } 190 191 /* only do something if we have a bulk out endpoint */ 192 if (serial->num_bulk_out) { 193 spin_lock_bh(&port->lock); 194 if (port->write_urb_busy) { 195 spin_unlock_bh(&port->lock); 196 dbg("%s - already writing", __FUNCTION__); 197 return 0; 198 } 199 port->write_urb_busy = 1; 200 spin_unlock_bh(&port->lock); 201 202 count = (count > port->bulk_out_size) ? port->bulk_out_size : count; 203 204 memcpy (port->write_urb->transfer_buffer, buf, count); 205 data = port->write_urb->transfer_buffer; 206 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data); 207 208 /* set up our urb */ 209 usb_fill_bulk_urb (port->write_urb, serial->dev, 210 usb_sndbulkpipe (serial->dev, 211 port->bulk_out_endpointAddress), 212 port->write_urb->transfer_buffer, count, 213 ((serial->type->write_bulk_callback) ? 214 serial->type->write_bulk_callback : 215 usb_serial_generic_write_bulk_callback), port); 216 217 /* send the data out the bulk port */ 218 port->write_urb_busy = 1; 219 result = usb_submit_urb(port->write_urb, GFP_ATOMIC); 220 if (result) { 221 dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result); 222 /* don't have to grab the lock here, as we will retry if != 0 */ 223 port->write_urb_busy = 0; 224 } else 225 result = count; 226 227 return result; 228 } 229 230 /* no bulk out, so return 0 bytes written */ 231 return 0; 232 } 233 234 int usb_serial_generic_write_room (struct usb_serial_port *port) 235 { 236 struct usb_serial *serial = port->serial; 237 int room = 0; 238 239 dbg("%s - port %d", __FUNCTION__, port->number); 240 241 if (serial->num_bulk_out) { 242 if (!(port->write_urb_busy)) 243 room = port->bulk_out_size; 244 } 245 246 dbg("%s - returns %d", __FUNCTION__, room); 247 return (room); 248 } 249 250 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port) 251 { 252 struct usb_serial *serial = port->serial; 253 int chars = 0; 254 255 dbg("%s - port %d", __FUNCTION__, port->number); 256 257 if (serial->num_bulk_out) { 258 if (port->write_urb_busy) 259 chars = port->write_urb->transfer_buffer_length; 260 } 261 262 dbg("%s - returns %d", __FUNCTION__, chars); 263 return (chars); 264 } 265 266 /* Push data to tty layer and resubmit the bulk read URB */ 267 static void flush_and_resubmit_read_urb (struct usb_serial_port *port) 268 { 269 struct usb_serial *serial = port->serial; 270 struct urb *urb = port->read_urb; 271 struct tty_struct *tty = port->tty; 272 int result; 273 274 /* Push data to tty */ 275 if (tty && urb->actual_length) { 276 tty_buffer_request_room(tty, urb->actual_length); 277 tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length); 278 tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */ 279 } 280 281 /* Continue reading from device */ 282 usb_fill_bulk_urb (port->read_urb, serial->dev, 283 usb_rcvbulkpipe (serial->dev, 284 port->bulk_in_endpointAddress), 285 port->read_urb->transfer_buffer, 286 port->read_urb->transfer_buffer_length, 287 ((serial->type->read_bulk_callback) ? 288 serial->type->read_bulk_callback : 289 usb_serial_generic_read_bulk_callback), port); 290 result = usb_submit_urb(port->read_urb, GFP_ATOMIC); 291 if (result) 292 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result); 293 } 294 295 void usb_serial_generic_read_bulk_callback (struct urb *urb) 296 { 297 struct usb_serial_port *port = (struct usb_serial_port *)urb->context; 298 unsigned char *data = urb->transfer_buffer; 299 int is_throttled; 300 unsigned long flags; 301 302 dbg("%s - port %d", __FUNCTION__, port->number); 303 304 if (urb->status) { 305 dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status); 306 return; 307 } 308 309 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data); 310 311 /* Throttle the device if requested by tty */ 312 if (urb->actual_length) { 313 spin_lock_irqsave(&port->lock, flags); 314 is_throttled = port->throttled = port->throttle_req; 315 spin_unlock_irqrestore(&port->lock, flags); 316 if (is_throttled) { 317 /* Let the received data linger in the read URB; 318 * usb_serial_generic_unthrottle() will pick it 319 * up later. */ 320 dbg("%s - throttling device", __FUNCTION__); 321 return; 322 } 323 } 324 325 /* Handle data and continue reading from device */ 326 flush_and_resubmit_read_urb(port); 327 } 328 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); 329 330 void usb_serial_generic_write_bulk_callback (struct urb *urb) 331 { 332 struct usb_serial_port *port = (struct usb_serial_port *)urb->context; 333 334 dbg("%s - port %d", __FUNCTION__, port->number); 335 336 port->write_urb_busy = 0; 337 if (urb->status) { 338 dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status); 339 return; 340 } 341 342 usb_serial_port_softint(port); 343 } 344 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback); 345 346 void usb_serial_generic_throttle (struct usb_serial_port *port) 347 { 348 unsigned long flags; 349 350 dbg("%s - port %d", __FUNCTION__, port->number); 351 352 /* Set the throttle request flag. It will be picked up 353 * by usb_serial_generic_read_bulk_callback(). */ 354 spin_lock_irqsave(&port->lock, flags); 355 port->throttle_req = 1; 356 spin_unlock_irqrestore(&port->lock, flags); 357 } 358 359 void usb_serial_generic_unthrottle (struct usb_serial_port *port) 360 { 361 int was_throttled; 362 unsigned long flags; 363 364 dbg("%s - port %d", __FUNCTION__, port->number); 365 366 /* Clear the throttle flags */ 367 spin_lock_irqsave(&port->lock, flags); 368 was_throttled = port->throttled; 369 port->throttled = port->throttle_req = 0; 370 spin_unlock_irqrestore(&port->lock, flags); 371 372 if (was_throttled) { 373 /* Handle pending data and resume reading from device */ 374 flush_and_resubmit_read_urb(port); 375 } 376 } 377 378 void usb_serial_generic_shutdown (struct usb_serial *serial) 379 { 380 int i; 381 382 dbg("%s", __FUNCTION__); 383 384 /* stop reads and writes on all ports */ 385 for (i=0; i < serial->num_ports; ++i) { 386 generic_cleanup(serial->port[i]); 387 } 388 } 389 390