drivers/usb/misc/usblcd.c

   1 /*****************************************************************************
   2  *                          USBLCD Kernel Driver                             *
   3  *        See http://www.usblcd.de for Hardware and Documentation.           *
   4  *                            Version 1.03                                   *
   5  *             (C) 2002 Adams IT Services <info@usblcd.de>                   *
   6  *                                                                           *
   7  *     This file is licensed under the GPL. See COPYING in the package.      *
   8  * Based on rio500.c by Cesar Miquel (miquel@df.uba.ar) which is based on    *
   9  * hp_scanner.c by David E. Nelson (dnelson@jump.net)                        *
  10  *                                                                           *
  11  * 23.7.02 RA changed minor device number to the official assigned one       *
  12  *****************************************************************************/
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/errno.h>
  18 #include <asm/uaccess.h>
  19 #include <linux/usb.h>
  20
  21 #define DRIVER_VERSION "USBLCD Driver Version 1.04"
  22
  23 #define USBLCD_MINOR            144
  24
  25 #define IOCTL_GET_HARD_VERSION  1
  26 #define IOCTL_GET_DRV_VERSION   2
  27
  28 /* stall/wait timeout for USBLCD */
  29 #define NAK_TIMEOUT     (10*HZ)
  30
  31 #define IBUF_SIZE       0x1000
  32 #define OBUF_SIZE       0x10000
  33
  34 struct lcd_usb_data {
  35         struct usb_device *lcd_dev;     /* init: probe_lcd */
  36         unsigned int ifnum;             /* Interface number of the USB device */
  37         int isopen;                     /* nz if open */
  38         int present;                    /* Device is present on the bus */
  39         char *obuf, *ibuf;              /* transfer buffers */
  40         char bulk_in_ep, bulk_out_ep;   /* Endpoint assignments */
  41         wait_queue_head_t wait_q;       /* for timeouts */
  42 };
  43
  44 static struct lcd_usb_data lcd_instance;
  45
  46 static int open_lcd(struct inode *inode, struct file *file)
  47 {
  48         struct lcd_usb_data *lcd = &lcd_instance;
  49
  50         if (lcd->isopen || !lcd->present) {
  51                 return -EBUSY;
  52         }
  53         lcd->isopen = 1;
  54
  55         init_waitqueue_head(&lcd->wait_q);
  56
  57         info("USBLCD opened.");
  58
  59         return 0;
  60 }
  61
  62 static int close_lcd(struct inode *inode, struct file *file)
  63 {
  64         struct lcd_usb_data *lcd = &lcd_instance;
  65
  66         lcd->isopen = 0;
  67
  68         info("USBLCD closed.");
  69         return 0;
  70 }
  71
  72 static int
  73 ioctl_lcd(struct inode *inode, struct file *file, unsigned int cmd,
  74           unsigned long arg)
  75 {
  76         struct lcd_usb_data *lcd = &lcd_instance;
  77         int i;
  78         char buf[30];
  79
  80         /* Sanity check to make sure lcd is connected, powered, etc */
  81         if (lcd == NULL ||
  82             lcd->present == 0 ||
  83             lcd->lcd_dev == NULL)
  84                 return -1;
  85
  86         switch (cmd) {
  87         case IOCTL_GET_HARD_VERSION:
  88                 i = (lcd->lcd_dev)->descriptor.bcdDevice;
  89                 sprintf(buf,"%1d%1d.%1d%1d",(i & 0xF000)>>12,(i & 0xF00)>>8,
  90                         (i & 0xF0)>>4,(i & 0xF));
  91                 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
  92                         return -EFAULT;
  93                 break;
  94         case IOCTL_GET_DRV_VERSION:
  95                 sprintf(buf,DRIVER_VERSION);
  96                 if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0)
  97                         return -EFAULT;
  98                 break;
  99         default:
 100                 return -ENOTTY;
 101                 break;
 102         }
 103
 104         return 0;
 105 }
 106
 107 static ssize_t
 108 write_lcd(struct file *file, const char __user *buffer,
 109           size_t count, loff_t * ppos)
 110 {
 111         struct lcd_usb_data *lcd = &lcd_instance;
 112
 113         unsigned long copy_size;
 114         unsigned long bytes_written = 0;
 115         unsigned int partial;
 116
 117         int result = 0;
 118         int maxretry;
 119
 120         /* Sanity check to make sure lcd is connected, powered, etc */
 121         if (lcd == NULL ||
 122             lcd->present == 0 ||
 123             lcd->lcd_dev == NULL)
 124                 return -1;
 125
 126         do {
 127                 unsigned long thistime;
 128                 char *obuf = lcd->obuf;
 129
 130                 thistime = copy_size =
 131                     (count >= OBUF_SIZE) ? OBUF_SIZE : count;
 132                 if (copy_from_user(lcd->obuf, buffer, copy_size))
 133                         return -EFAULT;
 134                 maxretry = 5;
 135                 while (thistime) {
 136                         if (!lcd->lcd_dev)
 137                                 return -ENODEV;
 138                         if (signal_pending(current)) {
 139                                 return bytes_written ? bytes_written : -EINTR;
 140                         }
 141
 142                         result = usb_bulk_msg(lcd->lcd_dev,
 143                                          usb_sndbulkpipe(lcd->lcd_dev, 1),
 144                                          obuf, thistime, &partial, 10 * HZ);
 145
 146                         dbg("write stats: result:%d thistime:%lu partial:%u",
 147                              result, thistime, partial);
 148
 149                         if (result == -ETIMEDOUT) {     /* NAK - so hold for a while */
 150                                 if (!maxretry--) {
 151                                         return -ETIME;
 152                                 }
 153                                 interruptible_sleep_on_timeout(&lcd-> wait_q, NAK_TIMEOUT);
 154                                 continue;
 155                         } else if (!result && partial) {
 156                                 obuf += partial;
 157                                 thistime -= partial;
 158                         } else
 159                                 break;
 160                 };
 161                 if (result) {
 162                         err("Write Whoops - %x", result);
 163                         return -EIO;
 164                 }
 165                 bytes_written += copy_size;
 166                 count -= copy_size;
 167                 buffer += copy_size;
 168         } while (count > 0);
 169
 170         return bytes_written ? bytes_written : -EIO;
 171 }
 172
 173 static ssize_t
 174 read_lcd(struct file *file, char __user *buffer, size_t count, loff_t * ppos)
 175 {
 176         struct lcd_usb_data *lcd = &lcd_instance;
 177         ssize_t read_count;
 178         unsigned int partial;
 179         int this_read;
 180         int result;
 181         int maxretry = 10;
 182         char *ibuf = lcd->ibuf;
 183
 184         /* Sanity check to make sure lcd is connected, powered, etc */
 185         if (lcd == NULL ||
 186             lcd->present == 0 ||
 187             lcd->lcd_dev == NULL)
 188                 return -1;
 189
 190         read_count = 0;
 191
 192         while (count > 0) {
 193                 if (signal_pending(current)) {
 194                         return read_count ? read_count : -EINTR;
 195                 }
 196                 if (!lcd->lcd_dev)
 197                         return -ENODEV;
 198                 this_read = (count >= IBUF_SIZE) ? IBUF_SIZE : count;
 199
 200                 result = usb_bulk_msg(lcd->lcd_dev,
 201                                       usb_rcvbulkpipe(lcd->lcd_dev, 0),
 202                                       ibuf, this_read, &partial,
 203                                       (int) (HZ * 8));
 204
 205                 dbg(KERN_DEBUG "read stats: result:%d this_read:%u partial:%u",
 206                        result, this_read, partial);
 207
 208                 if (partial) {
 209                         count = this_read = partial;
 210                 } else if (result == -ETIMEDOUT || result == 15) {      /* FIXME: 15 ??? */
 211                         if (!maxretry--) {
 212                                 err("read_lcd: maxretry timeout");
 213                                 return -ETIME;
 214                         }
 215                         interruptible_sleep_on_timeout(&lcd->wait_q,
 216                                                        NAK_TIMEOUT);
 217                         continue;
 218                 } else if (result != -EREMOTEIO) {
 219                         err("Read Whoops - result:%u partial:%u this_read:%u",
 220                              result, partial, this_read);
 221                         return -EIO;
 222                 } else {
 223                         return (0);
 224                 }
 225
 226                 if (this_read) {
 227                         if (copy_to_user(buffer, ibuf, this_read))
 228                                 return -EFAULT;
 229                         count -= this_read;
 230                         read_count += this_read;
 231                         buffer += this_read;
 232                 }
 233         }
 234         return read_count;
 235 }
 236
 237 static struct
 238 file_operations usb_lcd_fops = {
 239         .owner =        THIS_MODULE,
 240         .read =         read_lcd,
 241         .write =        write_lcd,
 242         .ioctl =        ioctl_lcd,
 243         .open =         open_lcd,
 244         .release =      close_lcd,
 245 };
 246
 247 static struct usb_class_driver usb_lcd_class = {
 248         .name =         "usb/lcd%d",
 249         .fops =         &usb_lcd_fops,
 250         .mode =         S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP,
 251         .minor_base =   USBLCD_MINOR,
 252 };
 253
 254 static int probe_lcd(struct usb_interface *intf, const struct usb_device_id *id)
 255 {
 256         struct usb_device *dev = interface_to_usbdev(intf);
 257         struct lcd_usb_data *lcd = &lcd_instance;
 258         int i;
 259         int retval;
 260
 261         if (dev->descriptor.idProduct != 0x0001  ) {
 262                 warn(KERN_INFO "USBLCD model not supported.");
 263                 return -ENODEV;
 264         }
 265
 266         if (lcd->present == 1) {
 267                 warn(KERN_INFO "Multiple USBLCDs are not supported!");
 268                 return -ENODEV;
 269         }
 270
 271         i = dev->descriptor.bcdDevice;
 272
 273         info("USBLCD Version %1d%1d.%1d%1d found at address %d",
 274                 (i & 0xF000)>>12,(i & 0xF00)>>8,(i & 0xF0)>>4,(i & 0xF),
 275                 dev->devnum);
 276
 277
 278
 279         lcd->present = 1;
 280         lcd->lcd_dev = dev;
 281
 282         if (!(lcd->obuf = (char *) kmalloc(OBUF_SIZE, GFP_KERNEL))) {
 283                 err("probe_lcd: Not enough memory for the output buffer");
 284                 return -ENOMEM;
 285         }
 286         dbg("probe_lcd: obuf address:%p", lcd->obuf);
 287
 288         if (!(lcd->ibuf = (char *) kmalloc(IBUF_SIZE, GFP_KERNEL))) {
 289                 err("probe_lcd: Not enough memory for the input buffer");
 290                 kfree(lcd->obuf);
 291                 return -ENOMEM;
 292         }
 293         dbg("probe_lcd: ibuf address:%p", lcd->ibuf);
 294
 295         retval = usb_register_dev(intf, &usb_lcd_class);
 296         if (retval) {
 297                 err("Not able to get a minor for this device.");
 298                 kfree(lcd->obuf);
 299                 kfree(lcd->ibuf);
 300                 return -ENOMEM;
 301         }
 302
 303         usb_set_intfdata (intf, lcd);
 304         return 0;
 305 }
 306
 307 static void disconnect_lcd(struct usb_interface *intf)
 308 {
 309         struct lcd_usb_data *lcd = usb_get_intfdata (intf);
 310
 311         usb_set_intfdata (intf, NULL);
 312         if (lcd) {
 313                 usb_deregister_dev(intf, &usb_lcd_class);
 314
 315                 if (lcd->isopen) {
 316                         lcd->isopen = 0;
 317                         /* better let it finish - the release will do whats needed */
 318                         lcd->lcd_dev = NULL;
 319                         return;
 320                 }
 321                 kfree(lcd->ibuf);
 322                 kfree(lcd->obuf);
 323
 324                 info("USBLCD disconnected.");
 325
 326                 lcd->present = 0;
 327         }
 328 }
 329
 330 static struct usb_device_id id_table [] = {
 331         { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, },
 332         {},
 333 };
 334
 335 MODULE_DEVICE_TABLE (usb, id_table);
 336
 337 static struct usb_driver lcd_driver = {
 338         .owner =        THIS_MODULE,
 339         .name =         "usblcd",
 340         .probe =        (void *)probe_lcd,
 341         .disconnect =   disconnect_lcd,
 342         .id_table =     id_table,
 343 };
 344
 345 static int __init usb_lcd_init(void)
 346 {
 347         int retval;
 348         retval = usb_register(&lcd_driver);
 349         if (retval)
 350                 goto out;
 351
 352         info("%s (C) Adams IT Services http://www.usblcd.de", DRIVER_VERSION);
 353         info("USBLCD support registered.");
 354 out:
 355         return retval;
 356 }
 357
 358
 359 static void __exit usb_lcd_cleanup(void)
 360 {
 361         struct lcd_usb_data *lcd = &lcd_instance;
 362
 363         lcd->present = 0;
 364         usb_deregister(&lcd_driver);
 365 }
 366
 367 module_init(usb_lcd_init);
 368 module_exit(usb_lcd_cleanup);
 369
 370 MODULE_AUTHOR("Adams IT Services <info@usblcd.de>");
 371 MODULE_DESCRIPTION(DRIVER_VERSION);
 372 MODULE_LICENSE("GPL");