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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
612de10d | 2 | /* |
1da177e4 LT |
3 | * Parallel port device probing code |
4 | * | |
5 | * Authors: Carsten Gross, carsten@sol.wohnheim.uni-ulm.de | |
6 | * Philip Blundell <philb@gnu.org> | |
7 | */ | |
8 | ||
9 | #include <linux/module.h> | |
10 | #include <linux/parport.h> | |
11 | #include <linux/ctype.h> | |
12 | #include <linux/string.h> | |
5a0e3ad6 | 13 | #include <linux/slab.h> |
7c0f6ba6 | 14 | #include <linux/uaccess.h> |
1da177e4 | 15 | |
a6767b7c MK |
16 | static const struct { |
17 | const char *token; | |
18 | const char *descr; | |
1da177e4 LT |
19 | } classes[] = { |
20 | { "", "Legacy device" }, | |
21 | { "PRINTER", "Printer" }, | |
22 | { "MODEM", "Modem" }, | |
23 | { "NET", "Network device" }, | |
24 | { "HDC", "Hard disk" }, | |
25 | { "PCMCIA", "PCMCIA" }, | |
26 | { "MEDIA", "Multimedia device" }, | |
27 | { "FDC", "Floppy disk" }, | |
28 | { "PORTS", "Ports" }, | |
29 | { "SCANNER", "Scanner" }, | |
30 | { "DIGICAM", "Digital camera" }, | |
31 | { "", "Unknown device" }, | |
32 | { "", "Unspecified" }, | |
33 | { "SCSIADAPTER", "SCSI adapter" }, | |
34 | { NULL, NULL } | |
35 | }; | |
36 | ||
37 | static void pretty_print(struct parport *port, int device) | |
38 | { | |
39 | struct parport_device_info *info = &port->probe_info[device + 1]; | |
40 | ||
decf26f6 | 41 | pr_info("%s", port->name); |
1da177e4 LT |
42 | |
43 | if (device >= 0) | |
aa3d6e7c | 44 | pr_cont(" (addr %d)", device); |
1da177e4 | 45 | |
aa3d6e7c | 46 | pr_cont(": %s", classes[info->class].descr); |
1da177e4 | 47 | if (info->class) |
aa3d6e7c | 48 | pr_cont(", %s %s", info->mfr, info->model); |
1da177e4 | 49 | |
aa3d6e7c | 50 | pr_cont("\n"); |
1da177e4 LT |
51 | } |
52 | ||
1da177e4 LT |
53 | static void parse_data(struct parport *port, int device, char *str) |
54 | { | |
55 | char *txt = kmalloc(strlen(str)+1, GFP_KERNEL); | |
56 | char *p = txt, *q; | |
57 | int guessed_class = PARPORT_CLASS_UNSPEC; | |
58 | struct parport_device_info *info = &port->probe_info[device + 1]; | |
59 | ||
60 | if (!txt) { | |
decf26f6 | 61 | pr_warn("%s probe: memory squeeze\n", port->name); |
1da177e4 LT |
62 | return; |
63 | } | |
64 | strcpy(txt, str); | |
65 | while (p) { | |
66 | char *sep; | |
67 | q = strchr(p, ';'); | |
68 | if (q) *q = 0; | |
69 | sep = strchr(p, ':'); | |
70 | if (sep) { | |
71 | char *u; | |
72 | *(sep++) = 0; | |
73 | /* Get rid of trailing blanks */ | |
74 | u = sep + strlen (sep) - 1; | |
75 | while (u >= p && *u == ' ') | |
76 | *u-- = '\0'; | |
77 | u = p; | |
78 | while (*u) { | |
79 | *u = toupper(*u); | |
80 | u++; | |
81 | } | |
82 | if (!strcmp(p, "MFG") || !strcmp(p, "MANUFACTURER")) { | |
6044ec88 | 83 | kfree(info->mfr); |
543537bd | 84 | info->mfr = kstrdup(sep, GFP_KERNEL); |
1da177e4 | 85 | } else if (!strcmp(p, "MDL") || !strcmp(p, "MODEL")) { |
6044ec88 | 86 | kfree(info->model); |
543537bd | 87 | info->model = kstrdup(sep, GFP_KERNEL); |
1da177e4 LT |
88 | } else if (!strcmp(p, "CLS") || !strcmp(p, "CLASS")) { |
89 | int i; | |
6044ec88 JJ |
90 | |
91 | kfree(info->class_name); | |
543537bd | 92 | info->class_name = kstrdup(sep, GFP_KERNEL); |
1da177e4 LT |
93 | for (u = sep; *u; u++) |
94 | *u = toupper(*u); | |
95 | for (i = 0; classes[i].token; i++) { | |
96 | if (!strcmp(classes[i].token, sep)) { | |
97 | info->class = i; | |
98 | goto rock_on; | |
99 | } | |
100 | } | |
decf26f6 JP |
101 | pr_warn("%s probe: warning, class '%s' not understood\n", |
102 | port->name, sep); | |
1da177e4 LT |
103 | info->class = PARPORT_CLASS_OTHER; |
104 | } else if (!strcmp(p, "CMD") || | |
105 | !strcmp(p, "COMMAND SET")) { | |
6044ec88 | 106 | kfree(info->cmdset); |
543537bd | 107 | info->cmdset = kstrdup(sep, GFP_KERNEL); |
1da177e4 LT |
108 | /* if it speaks printer language, it's |
109 | probably a printer */ | |
110 | if (strstr(sep, "PJL") || strstr(sep, "PCL")) | |
111 | guessed_class = PARPORT_CLASS_PRINTER; | |
112 | } else if (!strcmp(p, "DES") || !strcmp(p, "DESCRIPTION")) { | |
6044ec88 | 113 | kfree(info->description); |
543537bd | 114 | info->description = kstrdup(sep, GFP_KERNEL); |
1da177e4 LT |
115 | } |
116 | } | |
117 | rock_on: | |
6044ec88 JJ |
118 | if (q) |
119 | p = q + 1; | |
120 | else | |
121 | p = NULL; | |
1da177e4 LT |
122 | } |
123 | ||
124 | /* If the device didn't tell us its class, maybe we have managed to | |
125 | guess one from the things it did say. */ | |
126 | if (info->class == PARPORT_CLASS_UNSPEC) | |
127 | info->class = guessed_class; | |
128 | ||
129 | pretty_print (port, device); | |
130 | ||
131 | kfree(txt); | |
132 | } | |
133 | ||
c6606290 MK |
134 | /* Read up to count-1 bytes of device id. Terminate buffer with |
135 | * '\0'. Buffer begins with two Device ID length bytes as given by | |
136 | * device. */ | |
137 | static ssize_t parport_read_device_id (struct parport *port, char *buffer, | |
138 | size_t count) | |
139 | { | |
140 | unsigned char length[2]; | |
141 | unsigned lelen, belen; | |
142 | size_t idlens[4]; | |
143 | unsigned numidlens; | |
144 | unsigned current_idlen; | |
145 | ssize_t retval; | |
146 | size_t len; | |
147 | ||
148 | /* First two bytes are MSB,LSB of inclusive length. */ | |
149 | retval = parport_read (port, length, 2); | |
150 | ||
151 | if (retval < 0) | |
152 | return retval; | |
153 | if (retval != 2) | |
154 | return -EIO; | |
155 | ||
156 | if (count < 2) | |
157 | return 0; | |
158 | memcpy(buffer, length, 2); | |
159 | len = 2; | |
160 | ||
161 | /* Some devices wrongly send LE length, and some send it two | |
162 | * bytes short. Construct a sorted array of lengths to try. */ | |
163 | belen = (length[0] << 8) + length[1]; | |
164 | lelen = (length[1] << 8) + length[0]; | |
165 | idlens[0] = min(belen, lelen); | |
166 | idlens[1] = idlens[0]+2; | |
167 | if (belen != lelen) { | |
168 | int off = 2; | |
efad798b | 169 | /* Don't try lengths of 0x100 and 0x200 as 1 and 2 */ |
c6606290 MK |
170 | if (idlens[0] <= 2) |
171 | off = 0; | |
172 | idlens[off] = max(belen, lelen); | |
173 | idlens[off+1] = idlens[off]+2; | |
174 | numidlens = off+2; | |
175 | } | |
176 | else { | |
177 | /* Some devices don't truly implement Device ID, but | |
178 | * just return constant nibble forever. This catches | |
179 | * also those cases. */ | |
180 | if (idlens[0] == 0 || idlens[0] > 0xFFF) { | |
aa3d6e7c JP |
181 | printk(KERN_DEBUG "%s: reported broken Device ID length of %#zX bytes\n", |
182 | port->name, idlens[0]); | |
c6606290 MK |
183 | return -EIO; |
184 | } | |
185 | numidlens = 2; | |
186 | } | |
187 | ||
188 | /* Try to respect the given ID length despite all the bugs in | |
189 | * the ID length. Read according to shortest possible ID | |
190 | * first. */ | |
191 | for (current_idlen = 0; current_idlen < numidlens; ++current_idlen) { | |
192 | size_t idlen = idlens[current_idlen]; | |
193 | if (idlen+1 >= count) | |
194 | break; | |
195 | ||
196 | retval = parport_read (port, buffer+len, idlen-len); | |
197 | ||
198 | if (retval < 0) | |
199 | return retval; | |
200 | len += retval; | |
201 | ||
202 | if (port->physport->ieee1284.phase != IEEE1284_PH_HBUSY_DAVAIL) { | |
203 | if (belen != len) { | |
aa3d6e7c JP |
204 | printk(KERN_DEBUG "%s: Device ID was %zd bytes while device told it would be %d bytes\n", |
205 | port->name, len, belen); | |
c6606290 MK |
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] == ';') { | |
aa3d6e7c JP |
215 | printk(KERN_DEBUG "%s: Device ID reading stopped before device told data not available. Current idlen %u of %u, len bytes %02X %02X\n", |
216 | port->name, current_idlen, numidlens, | |
217 | length[0], length[1]); | |
c6606290 MK |
218 | goto done; |
219 | } | |
220 | } | |
221 | if (current_idlen < numidlens) { | |
222 | /* Buffer not large enough, read to end of buffer. */ | |
223 | size_t idlen, len2; | |
224 | if (len+1 < count) { | |
225 | retval = parport_read (port, buffer+len, count-len-1); | |
226 | if (retval < 0) | |
227 | return retval; | |
228 | len += retval; | |
229 | } | |
230 | /* Read the whole ID since some devices would not | |
231 | * otherwise give back the Device ID from beginning | |
232 | * next time when asked. */ | |
233 | idlen = idlens[current_idlen]; | |
234 | len2 = len; | |
235 | while(len2 < idlen && retval > 0) { | |
236 | char tmp[4]; | |
237 | retval = parport_read (port, tmp, | |
238 | min(sizeof tmp, idlen-len2)); | |
239 | if (retval < 0) | |
240 | return retval; | |
241 | len2 += retval; | |
242 | } | |
243 | } | |
244 | /* In addition, there are broken devices out there that don't | |
245 | even finish off with a semi-colon. We do not need to care | |
246 | about those at this time. */ | |
247 | done: | |
248 | buffer[len] = '\0'; | |
249 | return len; | |
250 | } | |
251 | ||
1da177e4 | 252 | /* Get Std 1284 Device ID. */ |
c6606290 | 253 | ssize_t parport_device_id (int devnum, char *buffer, size_t count) |
1da177e4 LT |
254 | { |
255 | ssize_t retval = -ENXIO; | |
c059d579 | 256 | struct pardevice *dev = parport_open(devnum, daisy_dev_name); |
1da177e4 LT |
257 | if (!dev) |
258 | return -ENXIO; | |
259 | ||
260 | parport_claim_or_block (dev); | |
261 | ||
c6606290 MK |
262 | /* Negotiate to compatibility mode, and then to device ID |
263 | * mode. (This so that we start form beginning of device ID if | |
264 | * already in device ID mode.) */ | |
1da177e4 LT |
265 | parport_negotiate (dev->port, IEEE1284_MODE_COMPAT); |
266 | retval = parport_negotiate (dev->port, | |
267 | IEEE1284_MODE_NIBBLE | IEEE1284_DEVICEID); | |
268 | ||
269 | if (!retval) { | |
c6606290 | 270 | retval = parport_read_device_id (dev->port, buffer, count); |
1da177e4 | 271 | parport_negotiate (dev->port, IEEE1284_MODE_COMPAT); |
c6606290 MK |
272 | if (retval > 2) |
273 | parse_data (dev->port, dev->daisy, buffer+2); | |
1da177e4 LT |
274 | } |
275 | ||
1da177e4 LT |
276 | parport_release (dev); |
277 | parport_close (dev); | |
278 | return retval; | |
279 | } |