drivers/parport/probe.c

   1 /*
   2  * Parallel port device probing code
   3  *
   4  * Authors:    Carsten Gross, carsten@sol.wohnheim.uni-ulm.de
   5  *             Philip Blundell <philb@gnu.org>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/parport.h>
  10 #include <linux/ctype.h>
  11 #include <linux/string.h>
  12 #include <asm/uaccess.h>
  13
  14 static const struct {
  15         const char *token;
  16         const char *descr;
  17 } classes[] = {
  18         { "",            "Legacy device" },
  19         { "PRINTER",     "Printer" },
  20         { "MODEM",       "Modem" },
  21         { "NET",         "Network device" },
  22         { "HDC",         "Hard disk" },
  23         { "PCMCIA",      "PCMCIA" },
  24         { "MEDIA",       "Multimedia device" },
  25         { "FDC",         "Floppy disk" },
  26         { "PORTS",       "Ports" },
  27         { "SCANNER",     "Scanner" },
  28         { "DIGICAM",     "Digital camera" },
  29         { "",            "Unknown device" },
  30         { "",            "Unspecified" },
  31         { "SCSIADAPTER", "SCSI adapter" },
  32         { NULL,          NULL }
  33 };
  34
  35 static void pretty_print(struct parport *port, int device)
  36 {
  37         struct parport_device_info *info = &port->probe_info[device + 1];
  38
  39         printk(KERN_INFO "%s", port->name);
  40
  41         if (device >= 0)
  42                 printk (" (addr %d)", device);
  43
  44         printk (": %s", classes[info->class].descr);
  45         if (info->class)
  46                 printk(", %s %s", info->mfr, info->model);
  47
  48         printk("\n");
  49 }
  50
  51 static void parse_data(struct parport *port, int device, char *str)
  52 {
  53         char *txt = kmalloc(strlen(str)+1, GFP_KERNEL);
  54         char *p = txt, *q;
  55         int guessed_class = PARPORT_CLASS_UNSPEC;
  56         struct parport_device_info *info = &port->probe_info[device + 1];
  57
  58         if (!txt) {
  59                 printk(KERN_WARNING "%s probe: memory squeeze\n", port->name);
  60                 return;
  61         }
  62         strcpy(txt, str);
  63         while (p) {
  64                 char *sep;
  65                 q = strchr(p, ';');
  66                 if (q) *q = 0;
  67                 sep = strchr(p, ':');
  68                 if (sep) {
  69                         char *u;
  70                         *(sep++) = 0;
  71                         /* Get rid of trailing blanks */
  72                         u = sep + strlen (sep) - 1;
  73                         while (u >= p && *u == ' ')
  74                                 *u-- = '\0';
  75                         u = p;
  76                         while (*u) {
  77                                 *u = toupper(*u);
  78                                 u++;
  79                         }
  80                         if (!strcmp(p, "MFG") || !strcmp(p, "MANUFACTURER")) {
  81                                 kfree(info->mfr);
  82                                 info->mfr = kstrdup(sep, GFP_KERNEL);
  83                         } else if (!strcmp(p, "MDL") || !strcmp(p, "MODEL")) {
  84                                 kfree(info->model);
  85                                 info->model = kstrdup(sep, GFP_KERNEL);
  86                         } else if (!strcmp(p, "CLS") || !strcmp(p, "CLASS")) {
  87                                 int i;
  88
  89                                 kfree(info->class_name);
  90                                 info->class_name = kstrdup(sep, GFP_KERNEL);
  91                                 for (u = sep; *u; u++)
  92                                         *u = toupper(*u);
  93                                 for (i = 0; classes[i].token; i++) {
  94                                         if (!strcmp(classes[i].token, sep)) {
  95                                                 info->class = i;
  96                                                 goto rock_on;
  97                                         }
  98                                 }
  99                                 printk(KERN_WARNING "%s probe: warning, class '%s' not understood.\n", port->name, sep);
 100                                 info->class = PARPORT_CLASS_OTHER;
 101                         } else if (!strcmp(p, "CMD") ||
 102                                    !strcmp(p, "COMMAND SET")) {
 103                                 kfree(info->cmdset);
 104                                 info->cmdset = kstrdup(sep, GFP_KERNEL);
 105                                 /* if it speaks printer language, it's
 106                                    probably a printer */
 107                                 if (strstr(sep, "PJL") || strstr(sep, "PCL"))
 108                                         guessed_class = PARPORT_CLASS_PRINTER;
 109                         } else if (!strcmp(p, "DES") || !strcmp(p, "DESCRIPTION")) {
 110                                 kfree(info->description);
 111                                 info->description = kstrdup(sep, GFP_KERNEL);
 112                         }
 113                 }
 114         rock_on:
 115                 if (q)
 116                         p = q + 1;
 117                 else
 118                         p = NULL;
 119         }
 120
 121         /* If the device didn't tell us its class, maybe we have managed to
 122            guess one from the things it did say. */
 123         if (info->class == PARPORT_CLASS_UNSPEC)
 124                 info->class = guessed_class;
 125
 126         pretty_print (port, device);
 127
 128         kfree(txt);
 129 }
 130
 131 /* Read up to count-1 bytes of device id. Terminate buffer with
 132  * '\0'. Buffer begins with two Device ID length bytes as given by
 133  * device. */
 134 static ssize_t parport_read_device_id (struct parport *port, char *buffer,
 135                                        size_t count)
 136 {
 137         unsigned char length[2];
 138         unsigned lelen, belen;
 139         size_t idlens[4];
 140         unsigned numidlens;
 141         unsigned current_idlen;
 142         ssize_t retval;
 143         size_t len;
 144
 145         /* First two bytes are MSB,LSB of inclusive length. */
 146         retval = parport_read (port, length, 2);
 147
 148         if (retval < 0)
 149                 return retval;
 150         if (retval != 2)
 151                 return -EIO;
 152
 153         if (count < 2)
 154                 return 0;
 155         memcpy(buffer, length, 2);
 156         len = 2;
 157
 158         /* Some devices wrongly send LE length, and some send it two
 159          * bytes short. Construct a sorted array of lengths to try. */
 160         belen = (length[0] << 8) + length[1];
 161         lelen = (length[1] << 8) + length[0];
 162         idlens[0] = min(belen, lelen);
 163         idlens[1] = idlens[0]+2;
 164         if (belen != lelen) {
 165                 int off = 2;
 166                 /* Don't try lengths of 0x100 and 0x200 as 1 and 2 */
 167                 if (idlens[0] <= 2)
 168                         off = 0;
 169                 idlens[off] = max(belen, lelen);
 170                 idlens[off+1] = idlens[off]+2;
 171                 numidlens = off+2;
 172         }
 173         else {
 174                 /* Some devices don't truly implement Device ID, but
 175                  * just return constant nibble forever. This catches
 176                  * also those cases. */
 177                 if (idlens[0] == 0 || idlens[0] > 0xFFF) {
 178                         printk (KERN_DEBUG "%s: reported broken Device ID"
 179                                 " length of %#zX bytes\n",
 180                                 port->name, idlens[0]);
 181                         return -EIO;
 182                 }
 183                 numidlens = 2;
 184         }
 185
 186         /* Try to respect the given ID length despite all the bugs in
 187          * the ID length. Read according to shortest possible ID
 188          * first. */
 189         for (current_idlen = 0; current_idlen < numidlens; ++current_idlen) {
 190                 size_t idlen = idlens[current_idlen];
 191                 if (idlen+1 >= count)
 192                         break;
 193
 194                 retval = parport_read (port, buffer+len, idlen-len);
 195
 196                 if (retval < 0)
 197                         return retval;
 198                 len += retval;
 199
 200                 if (port->physport->ieee1284.phase != IEEE1284_PH_HBUSY_DAVAIL) {
 201                         if (belen != len) {
 202                                 printk (KERN_DEBUG "%s: Device ID was %zd bytes"
 203                                         " while device told it would be %d"
 204                                         " bytes\n",
 205                                         port->name, len, belen);
 206                         }
 207                         goto done;
 208                 }
 209
 210                 /* This might end reading the Device ID too
 211                  * soon. Hopefully the needed fields were already in
 212                  * the first 256 bytes or so that we must have read so
 213                  * far. */
 214                 if (buffer[len-1] == ';') {
 215                         printk (KERN_DEBUG "%s: Device ID reading stopped"
 216                                 " before device told data not available. "
 217                                 "Current idlen %u of %u, len bytes %02X %02X\n",
 218                                 port->name, current_idlen, numidlens,
 219                                 length[0], length[1]);
 220                         goto done;
 221                 }
 222         }
 223         if (current_idlen < numidlens) {
 224                 /* Buffer not large enough, read to end of buffer. */
 225                 size_t idlen, len2;
 226                 if (len+1 < count) {
 227                         retval = parport_read (port, buffer+len, count-len-1);
 228                         if (retval < 0)
 229                                 return retval;
 230                         len += retval;
 231                 }
 232                 /* Read the whole ID since some devices would not
 233                  * otherwise give back the Device ID from beginning
 234                  * next time when asked. */
 235                 idlen = idlens[current_idlen];
 236                 len2 = len;
 237                 while(len2 < idlen && retval > 0) {
 238                         char tmp[4];
 239                         retval = parport_read (port, tmp,
 240                                                min(sizeof tmp, idlen-len2));
 241                         if (retval < 0)
 242                                 return retval;
 243                         len2 += retval;
 244                 }
 245         }
 246         /* In addition, there are broken devices out there that don't
 247            even finish off with a semi-colon. We do not need to care
 248            about those at this time. */
 249  done:
 250         buffer[len] = '\0';
 251         return len;
 252 }
 253
 254 /* Get Std 1284 Device ID. */
 255 ssize_t parport_device_id (int devnum, char *buffer, size_t count)
 256 {
 257         ssize_t retval = -ENXIO;
 258         struct pardevice *dev = parport_open (devnum, "Device ID probe");
 259         if (!dev)
 260                 return -ENXIO;
 261
 262         parport_claim_or_block (dev);
 263
 264         /* Negotiate to compatibility mode, and then to device ID
 265          * mode. (This so that we start form beginning of device ID if
 266          * already in device ID mode.) */
 267         parport_negotiate (dev->port, IEEE1284_MODE_COMPAT);
 268         retval = parport_negotiate (dev->port,
 269                                     IEEE1284_MODE_NIBBLE | IEEE1284_DEVICEID);
 270
 271         if (!retval) {
 272                 retval = parport_read_device_id (dev->port, buffer, count);
 273                 parport_negotiate (dev->port, IEEE1284_MODE_COMPAT);
 274                 if (retval > 2)
 275                         parse_data (dev->port, dev->daisy, buffer+2);
 276         }
 277
 278         parport_release (dev);
 279         parport_close (dev);
 280         return retval;
 281 }