xref: /linux/drivers/parport/probe.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
1 /* $Id: parport_probe.c,v 1.1 1999/07/03 08:56:17 davem Exp $
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 struct {
15 	char *token;
16 	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 /* Get Std 1284 Device ID. */
132 ssize_t parport_device_id (int devnum, char *buffer, size_t len)
133 {
134 	ssize_t retval = -ENXIO;
135 	struct pardevice *dev = parport_open (devnum, "Device ID probe",
136 					      NULL, NULL, NULL, 0, NULL);
137 	if (!dev)
138 		return -ENXIO;
139 
140 	parport_claim_or_block (dev);
141 
142 	/* Negotiate to compatibility mode, and then to device ID mode.
143 	 * (This is in case we are already in device ID mode.) */
144 	parport_negotiate (dev->port, IEEE1284_MODE_COMPAT);
145 	retval = parport_negotiate (dev->port,
146 				    IEEE1284_MODE_NIBBLE | IEEE1284_DEVICEID);
147 
148 	if (!retval) {
149 		int idlen;
150 		unsigned char length[2];
151 
152 		/* First two bytes are MSB,LSB of inclusive length. */
153 		retval = parport_read (dev->port, length, 2);
154 
155 		if (retval != 2) goto end_id;
156 
157 		idlen = (length[0] << 8) + length[1] - 2;
158 		/*
159 		 * Check if the caller-allocated buffer is large enough
160 		 * otherwise bail out or there will be an at least off by one.
161 		 */
162 		if (idlen + 1 < len)
163 			len = idlen;
164 		else {
165 			retval = -EINVAL;
166 			goto out;
167 		}
168 		retval = parport_read (dev->port, buffer, len);
169 
170 		if (retval != len)
171 			printk (KERN_DEBUG "%s: only read %Zd of %Zd ID bytes\n",
172 				dev->port->name, retval,
173 				len);
174 
175 		/* Some printer manufacturers mistakenly believe that
176                    the length field is supposed to be _exclusive_.
177 		   In addition, there are broken devices out there
178                    that don't even finish off with a semi-colon. */
179 		if (buffer[len - 1] != ';') {
180 			ssize_t diff;
181 			diff = parport_read (dev->port, buffer + len, 2);
182 			retval += diff;
183 
184 			if (diff)
185 				printk (KERN_DEBUG
186 					"%s: device reported incorrect "
187 					"length field (%d, should be %Zd)\n",
188 					dev->port->name, idlen, retval);
189 			else {
190 				/* One semi-colon short of a device ID. */
191 				buffer[len++] = ';';
192 				printk (KERN_DEBUG "%s: faking semi-colon\n",
193 					dev->port->name);
194 
195 				/* If we get here, I don't think we
196                                    need to worry about the possible
197                                    standard violation of having read
198                                    more than we were told to.  The
199                                    device is non-compliant anyhow. */
200 			}
201 		}
202 
203 	end_id:
204 		buffer[len] = '\0';
205 		parport_negotiate (dev->port, IEEE1284_MODE_COMPAT);
206 	}
207 
208 	if (retval > 2)
209 		parse_data (dev->port, dev->daisy, buffer);
210 
211 out:
212 	parport_release (dev);
213 	parport_close (dev);
214 	return retval;
215 }
216