284 lines
7.4 KiB
C
284 lines
7.4 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Parallel port device probing code
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*
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* Authors: Carsten Gross, carsten@sol.wohnheim.uni-ulm.de
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* Philip Blundell <philb@gnu.org>
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*/
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#include <linux/module.h>
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#include <linux/parport.h>
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#include <linux/ctype.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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static const struct {
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const char *token;
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const char *descr;
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} classes[] = {
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{ "", "Legacy device" },
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{ "PRINTER", "Printer" },
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{ "MODEM", "Modem" },
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{ "NET", "Network device" },
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{ "HDC", "Hard disk" },
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{ "PCMCIA", "PCMCIA" },
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{ "MEDIA", "Multimedia device" },
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{ "FDC", "Floppy disk" },
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{ "PORTS", "Ports" },
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{ "SCANNER", "Scanner" },
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{ "DIGICAM", "Digital camera" },
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{ "", "Unknown device" },
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{ "", "Unspecified" },
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{ "SCSIADAPTER", "SCSI adapter" },
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{ NULL, NULL }
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};
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static void pretty_print(struct parport *port, int device)
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{
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struct parport_device_info *info = &port->probe_info[device + 1];
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printk(KERN_INFO "%s", port->name);
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if (device >= 0)
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printk (" (addr %d)", device);
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printk (": %s", classes[info->class].descr);
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if (info->class)
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printk(", %s %s", info->mfr, info->model);
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printk("\n");
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}
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static void parse_data(struct parport *port, int device, char *str)
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{
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char *txt = kmalloc(strlen(str)+1, GFP_KERNEL);
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char *p = txt, *q;
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int guessed_class = PARPORT_CLASS_UNSPEC;
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struct parport_device_info *info = &port->probe_info[device + 1];
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if (!txt) {
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printk(KERN_WARNING "%s probe: memory squeeze\n", port->name);
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return;
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}
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strcpy(txt, str);
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while (p) {
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char *sep;
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q = strchr(p, ';');
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if (q) *q = 0;
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sep = strchr(p, ':');
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if (sep) {
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char *u;
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*(sep++) = 0;
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/* Get rid of trailing blanks */
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u = sep + strlen (sep) - 1;
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while (u >= p && *u == ' ')
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*u-- = '\0';
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u = p;
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while (*u) {
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*u = toupper(*u);
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u++;
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}
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if (!strcmp(p, "MFG") || !strcmp(p, "MANUFACTURER")) {
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kfree(info->mfr);
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info->mfr = kstrdup(sep, GFP_KERNEL);
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} else if (!strcmp(p, "MDL") || !strcmp(p, "MODEL")) {
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kfree(info->model);
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info->model = kstrdup(sep, GFP_KERNEL);
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} else if (!strcmp(p, "CLS") || !strcmp(p, "CLASS")) {
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int i;
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kfree(info->class_name);
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info->class_name = kstrdup(sep, GFP_KERNEL);
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for (u = sep; *u; u++)
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*u = toupper(*u);
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for (i = 0; classes[i].token; i++) {
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if (!strcmp(classes[i].token, sep)) {
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info->class = i;
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goto rock_on;
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}
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}
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printk(KERN_WARNING "%s probe: warning, class '%s' not understood.\n", port->name, sep);
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info->class = PARPORT_CLASS_OTHER;
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} else if (!strcmp(p, "CMD") ||
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!strcmp(p, "COMMAND SET")) {
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kfree(info->cmdset);
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info->cmdset = kstrdup(sep, GFP_KERNEL);
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/* if it speaks printer language, it's
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probably a printer */
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if (strstr(sep, "PJL") || strstr(sep, "PCL"))
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guessed_class = PARPORT_CLASS_PRINTER;
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} else if (!strcmp(p, "DES") || !strcmp(p, "DESCRIPTION")) {
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kfree(info->description);
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info->description = kstrdup(sep, GFP_KERNEL);
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}
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}
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rock_on:
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if (q)
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p = q + 1;
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else
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p = NULL;
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}
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/* If the device didn't tell us its class, maybe we have managed to
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guess one from the things it did say. */
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if (info->class == PARPORT_CLASS_UNSPEC)
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info->class = guessed_class;
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pretty_print (port, device);
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kfree(txt);
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}
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/* Read up to count-1 bytes of device id. Terminate buffer with
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* '\0'. Buffer begins with two Device ID length bytes as given by
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* device. */
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static ssize_t parport_read_device_id (struct parport *port, char *buffer,
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size_t count)
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{
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unsigned char length[2];
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unsigned lelen, belen;
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size_t idlens[4];
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unsigned numidlens;
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unsigned current_idlen;
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ssize_t retval;
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size_t len;
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/* First two bytes are MSB,LSB of inclusive length. */
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retval = parport_read (port, length, 2);
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if (retval < 0)
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return retval;
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if (retval != 2)
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return -EIO;
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if (count < 2)
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return 0;
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memcpy(buffer, length, 2);
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len = 2;
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/* Some devices wrongly send LE length, and some send it two
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* bytes short. Construct a sorted array of lengths to try. */
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belen = (length[0] << 8) + length[1];
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lelen = (length[1] << 8) + length[0];
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idlens[0] = min(belen, lelen);
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idlens[1] = idlens[0]+2;
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if (belen != lelen) {
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int off = 2;
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/* Don't try lengths of 0x100 and 0x200 as 1 and 2 */
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if (idlens[0] <= 2)
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off = 0;
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idlens[off] = max(belen, lelen);
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idlens[off+1] = idlens[off]+2;
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numidlens = off+2;
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}
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else {
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/* Some devices don't truly implement Device ID, but
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* just return constant nibble forever. This catches
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* also those cases. */
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if (idlens[0] == 0 || idlens[0] > 0xFFF) {
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printk (KERN_DEBUG "%s: reported broken Device ID"
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" length of %#zX bytes\n",
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port->name, idlens[0]);
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return -EIO;
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}
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numidlens = 2;
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}
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/* Try to respect the given ID length despite all the bugs in
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* the ID length. Read according to shortest possible ID
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* first. */
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for (current_idlen = 0; current_idlen < numidlens; ++current_idlen) {
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size_t idlen = idlens[current_idlen];
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if (idlen+1 >= count)
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break;
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retval = parport_read (port, buffer+len, idlen-len);
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if (retval < 0)
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return retval;
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len += retval;
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if (port->physport->ieee1284.phase != IEEE1284_PH_HBUSY_DAVAIL) {
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if (belen != len) {
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printk (KERN_DEBUG "%s: Device ID was %zd bytes"
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" while device told it would be %d"
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" bytes\n",
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port->name, len, belen);
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}
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goto done;
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}
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/* This might end reading the Device ID too
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* soon. Hopefully the needed fields were already in
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* the first 256 bytes or so that we must have read so
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* far. */
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if (buffer[len-1] == ';') {
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printk (KERN_DEBUG "%s: Device ID reading stopped"
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" before device told data not available. "
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"Current idlen %u of %u, len bytes %02X %02X\n",
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port->name, current_idlen, numidlens,
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length[0], length[1]);
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goto done;
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}
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}
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if (current_idlen < numidlens) {
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/* Buffer not large enough, read to end of buffer. */
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size_t idlen, len2;
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if (len+1 < count) {
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retval = parport_read (port, buffer+len, count-len-1);
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if (retval < 0)
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return retval;
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len += retval;
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}
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/* Read the whole ID since some devices would not
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* otherwise give back the Device ID from beginning
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* next time when asked. */
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idlen = idlens[current_idlen];
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len2 = len;
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while(len2 < idlen && retval > 0) {
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char tmp[4];
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retval = parport_read (port, tmp,
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min(sizeof tmp, idlen-len2));
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if (retval < 0)
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return retval;
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len2 += retval;
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}
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}
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/* In addition, there are broken devices out there that don't
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even finish off with a semi-colon. We do not need to care
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about those at this time. */
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done:
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buffer[len] = '\0';
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return len;
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}
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/* Get Std 1284 Device ID. */
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ssize_t parport_device_id (int devnum, char *buffer, size_t count)
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{
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ssize_t retval = -ENXIO;
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struct pardevice *dev = parport_open (devnum, "Device ID probe");
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if (!dev)
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return -ENXIO;
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parport_claim_or_block (dev);
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/* Negotiate to compatibility mode, and then to device ID
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* mode. (This so that we start form beginning of device ID if
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* already in device ID mode.) */
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parport_negotiate (dev->port, IEEE1284_MODE_COMPAT);
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retval = parport_negotiate (dev->port,
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IEEE1284_MODE_NIBBLE | IEEE1284_DEVICEID);
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if (!retval) {
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retval = parport_read_device_id (dev->port, buffer, count);
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parport_negotiate (dev->port, IEEE1284_MODE_COMPAT);
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if (retval > 2)
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parse_data (dev->port, dev->daisy, buffer+2);
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}
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parport_release (dev);
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parport_close (dev);
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return retval;
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}
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