282 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			282 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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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 <asm/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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