drivers/usb/serial/generic.c

   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/config.h>
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/slab.h>
  16 #include <linux/tty.h>
  17 #include <linux/tty_flip.h>
  18 #include <linux/module.h>
  19 #include <linux/moduleparam.h>
  20 #include <linux/usb.h>
  21 #include <asm/uaccess.h>
  22 #include "usb-serial.h"
  23
  24 static int debug;
  25
  26 #ifdef CONFIG_USB_SERIAL_GENERIC
  27 static __u16 vendor  = 0x05f9;
  28 static __u16 product = 0xffff;
  29
  30 module_param(vendor, ushort, 0);
  31 MODULE_PARM_DESC(vendor, "User specified USB idVendor");
  32
  33 module_param(product, ushort, 0);
  34 MODULE_PARM_DESC(product, "User specified USB idProduct");
  35
  36 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
  37
  38 /* All of the device info needed for the Generic Serial Converter */
  39 struct usb_serial_driver usb_serial_generic_device = {
  40         .driver = {
  41                 .owner =        THIS_MODULE,
  42                 .name =         "generic",
  43         },
  44         .id_table =             generic_device_ids,
  45         .num_interrupt_in =     NUM_DONT_CARE,
  46         .num_bulk_in =          NUM_DONT_CARE,
  47         .num_bulk_out =         NUM_DONT_CARE,
  48         .num_ports =            1,
  49         .shutdown =             usb_serial_generic_shutdown,
  50 };
  51
  52 /* we want to look at all devices, as the vendor/product id can change
  53  * depending on the command line argument */
  54 static struct usb_device_id generic_serial_ids[] = {
  55         {.driver_info = 42},
  56         {}
  57 };
  58
  59 static int generic_probe(struct usb_interface *interface,
  60                                const struct usb_device_id *id)
  61 {
  62         const struct usb_device_id *id_pattern;
  63
  64         id_pattern = usb_match_id(interface, generic_device_ids);
  65         if (id_pattern != NULL)
  66                 return usb_serial_probe(interface, id);
  67         return -ENODEV;
  68 }
  69
  70 static struct usb_driver generic_driver = {
  71         .owner =        THIS_MODULE,
  72         .name =         "usbserial_generic",
  73         .probe =        generic_probe,
  74         .disconnect =   usb_serial_disconnect,
  75         .id_table =     generic_serial_ids,
  76         .no_dynamic_id =        1,
  77 };
  78 #endif
  79
  80 int usb_serial_generic_register (int _debug)
  81 {
  82         int retval = 0;
  83
  84         debug = _debug;
  85 #ifdef CONFIG_USB_SERIAL_GENERIC
  86         generic_device_ids[0].idVendor = vendor;
  87         generic_device_ids[0].idProduct = product;
  88         generic_device_ids[0].match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
  89
  90         /* register our generic driver with ourselves */
  91         retval = usb_serial_register (&usb_serial_generic_device);
  92         if (retval)
  93                 goto exit;
  94         retval = usb_register(&generic_driver);
  95         if (retval)
  96                 usb_serial_deregister(&usb_serial_generic_device);
  97 exit:
  98 #endif
  99         return retval;
 100 }
 101
 102 void usb_serial_generic_deregister (void)
 103 {
 104 #ifdef CONFIG_USB_SERIAL_GENERIC
 105         /* remove our generic driver */
 106         usb_deregister(&generic_driver);
 107         usb_serial_deregister (&usb_serial_generic_device);
 108 #endif
 109 }
 110
 111 int usb_serial_generic_open (struct usb_serial_port *port, struct file *filp)
 112 {
 113         struct usb_serial *serial = port->serial;
 114         int result = 0;
 115
 116         dbg("%s - port %d", __FUNCTION__, port->number);
 117
 118         /* force low_latency on so that our tty_push actually forces the data through,
 119            otherwise it is scheduled, and with high data rates (like with OHCI) data
 120            can get lost. */
 121         if (port->tty)
 122                 port->tty->low_latency = 1;
 123
 124         /* if we have a bulk interrupt, start reading from it */
 125         if (serial->num_bulk_in) {
 126                 /* Start reading from the device */
 127                 usb_fill_bulk_urb (port->read_urb, serial->dev,
 128                                    usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress),
 129                                    port->read_urb->transfer_buffer,
 130                                    port->read_urb->transfer_buffer_length,
 131                                    ((serial->type->read_bulk_callback) ?
 132                                      serial->type->read_bulk_callback :
 133                                      usb_serial_generic_read_bulk_callback),
 134                                    port);
 135                 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 136                 if (result)
 137                         dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 138         }
 139
 140         return result;
 141 }
 142
 143 static void generic_cleanup (struct usb_serial_port *port)
 144 {
 145         struct usb_serial *serial = port->serial;
 146
 147         dbg("%s - port %d", __FUNCTION__, port->number);
 148
 149         if (serial->dev) {
 150                 /* shutdown any bulk reads that might be going on */
 151                 if (serial->num_bulk_out)
 152                         usb_kill_urb(port->write_urb);
 153                 if (serial->num_bulk_in)
 154                         usb_kill_urb(port->read_urb);
 155         }
 156 }
 157
 158 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
 159 {
 160         dbg("%s - port %d", __FUNCTION__, port->number);
 161         generic_cleanup (port);
 162 }
 163
 164 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
 165 {
 166         struct usb_serial *serial = port->serial;
 167         int result;
 168         unsigned char *data;
 169
 170         dbg("%s - port %d", __FUNCTION__, port->number);
 171
 172         if (count == 0) {
 173                 dbg("%s - write request of 0 bytes", __FUNCTION__);
 174                 return (0);
 175         }
 176
 177         /* only do something if we have a bulk out endpoint */
 178         if (serial->num_bulk_out) {
 179                 spin_lock(&port->lock);
 180                 if (port->write_urb_busy) {
 181                         spin_unlock(&port->lock);
 182                         dbg("%s - already writing", __FUNCTION__);
 183                         return 0;
 184                 }
 185                 port->write_urb_busy = 1;
 186                 spin_unlock(&port->lock);
 187
 188                 count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
 189
 190                 memcpy (port->write_urb->transfer_buffer, buf, count);
 191                 data = port->write_urb->transfer_buffer;
 192                 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
 193
 194                 /* set up our urb */
 195                 usb_fill_bulk_urb (port->write_urb, serial->dev,
 196                                    usb_sndbulkpipe (serial->dev,
 197                                                     port->bulk_out_endpointAddress),
 198                                    port->write_urb->transfer_buffer, count,
 199                                    ((serial->type->write_bulk_callback) ?
 200                                      serial->type->write_bulk_callback :
 201                                      usb_serial_generic_write_bulk_callback), port);
 202
 203                 /* send the data out the bulk port */
 204                 port->write_urb_busy = 1;
 205                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
 206                 if (result) {
 207                         dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
 208                         /* don't have to grab the lock here, as we will retry if != 0 */
 209                         port->write_urb_busy = 0;
 210                 } else
 211                         result = count;
 212
 213                 return result;
 214         }
 215
 216         /* no bulk out, so return 0 bytes written */
 217         return 0;
 218 }
 219
 220 int usb_serial_generic_write_room (struct usb_serial_port *port)
 221 {
 222         struct usb_serial *serial = port->serial;
 223         int room = 0;
 224
 225         dbg("%s - port %d", __FUNCTION__, port->number);
 226
 227         if (serial->num_bulk_out) {
 228                 if (!(port->write_urb_busy))
 229                         room = port->bulk_out_size;
 230         }
 231
 232         dbg("%s - returns %d", __FUNCTION__, room);
 233         return (room);
 234 }
 235
 236 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
 237 {
 238         struct usb_serial *serial = port->serial;
 239         int chars = 0;
 240
 241         dbg("%s - port %d", __FUNCTION__, port->number);
 242
 243         if (serial->num_bulk_out) {
 244                 if (port->write_urb_busy)
 245                         chars = port->write_urb->transfer_buffer_length;
 246         }
 247
 248         dbg("%s - returns %d", __FUNCTION__, chars);
 249         return (chars);
 250 }
 251
 252 void usb_serial_generic_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
 253 {
 254         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 255         struct usb_serial *serial = port->serial;
 256         struct tty_struct *tty;
 257         unsigned char *data = urb->transfer_buffer;
 258         int i;
 259         int result;
 260
 261         dbg("%s - port %d", __FUNCTION__, port->number);
 262
 263         if (urb->status) {
 264                 dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
 265                 return;
 266         }
 267
 268         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
 269
 270         tty = port->tty;
 271         if (tty && urb->actual_length) {
 272                 for (i = 0; i < urb->actual_length ; ++i) {
 273                         /* if we insert more than TTY_FLIPBUF_SIZE characters, we drop them. */
 274                         if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
 275                                 tty_flip_buffer_push(tty);
 276                         }
 277                         /* this doesn't actually push the data through unless tty->low_latency is set */
 278                         tty_insert_flip_char(tty, data[i], 0);
 279                 }
 280                 tty_flip_buffer_push(tty);
 281         }
 282
 283         /* Continue trying to always read  */
 284         usb_fill_bulk_urb (port->read_urb, serial->dev,
 285                            usb_rcvbulkpipe (serial->dev,
 286                                             port->bulk_in_endpointAddress),
 287                            port->read_urb->transfer_buffer,
 288                            port->read_urb->transfer_buffer_length,
 289                            ((serial->type->read_bulk_callback) ?
 290                              serial->type->read_bulk_callback :
 291                              usb_serial_generic_read_bulk_callback), port);
 292         result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
 293         if (result)
 294                 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
 295 }
 296
 297 void usb_serial_generic_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
 298 {
 299         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
 300
 301         dbg("%s - port %d", __FUNCTION__, port->number);
 302
 303         port->write_urb_busy = 0;
 304         if (urb->status) {
 305                 dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
 306                 return;
 307         }
 308
 309         usb_serial_port_softint((void *)port);
 310
 311         schedule_work(&port->work);
 312 }
 313 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
 314
 315 void usb_serial_generic_shutdown (struct usb_serial *serial)
 316 {
 317         int i;
 318
 319         dbg("%s", __FUNCTION__);
 320
 321         /* stop reads and writes on all ports */
 322         for (i=0; i < serial->num_ports; ++i) {
 323                 generic_cleanup(serial->port[i]);
 324         }
 325 }
 326