| 1 | .\" gsc.4 - manual page for the scanner device driver `gsc' |
| 2 | .\" |
| 3 | .\" |
| 4 | .\" Copyright (c) 1995 Gunther Schadow. All rights reserved. |
| 5 | .\" |
| 6 | .\" Redistribution and use in source and binary forms, with or without |
| 7 | .\" modification, are permitted provided that the following conditions |
| 8 | .\" are met: |
| 9 | .\" 1. Redistributions of source code must retain the above copyright |
| 10 | .\" notice, this list of conditions and the following disclaimer. |
| 11 | .\" 2. Redistributions in binary form must reproduce the above copyright |
| 12 | .\" notice, this list of conditions and the following disclaimer in the |
| 13 | .\" documentation and/or other materials provided with the distribution. |
| 14 | .\" 3. All advertising materials mentioning features or use of this software |
| 15 | .\" must display the following acknowledgement: |
| 16 | .\" This product includes software developed by Gunther Schadow. |
| 17 | .\" 4. The name of the author may not be used to endorse or promote products |
| 18 | .\" derived from this software without specific prior written permission. |
| 19 | .\" |
| 20 | .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 21 | .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 22 | .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 23 | .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 24 | .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 25 | .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 26 | .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 27 | .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 28 | .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 29 | .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 30 | .\" |
| 31 | .\" $FreeBSD: src/share/man/man4/man4.i386/gsc.4,v 1.12.2.7 2001/12/17 11:30:13 ru Exp $ |
| 32 | .\" |
| 33 | .Dd January 9, 1995 |
| 34 | .Dt GSC 4 i386 |
| 35 | .Os |
| 36 | .Sh NAME |
| 37 | .Nm gsc |
| 38 | .Nd a device driver for a handy scanner |
| 39 | .Sh SYNOPSIS |
| 40 | .In machine/gsc.h |
| 41 | .Pp |
| 42 | .Cd Minor number bits: Ar uu d g p ... |
| 43 | .Bl -tag -width "uu " -compact -offset indent |
| 44 | .It Ar uu |
| 45 | unit gsc0 .. gsc3 |
| 46 | .It Ar d |
| 47 | selects logging of |
| 48 | .Em debug |
| 49 | messages |
| 50 | .It Ar g |
| 51 | selects |
| 52 | .Em bitmap |
| 53 | vs. |
| 54 | .Em graymap |
| 55 | output |
| 56 | .It Ar p |
| 57 | selects |
| 58 | .Em raw |
| 59 | vs. portable |
| 60 | .Em pnm |
| 61 | output |
| 62 | .El |
| 63 | .Sh DESCRIPTION |
| 64 | The |
| 65 | .Nm |
| 66 | character device driver currently handles only the |
| 67 | Genius GS-4500 handy scanner. |
| 68 | It operates in pure DMA modes, although |
| 69 | the hardware could be set up to work with irq. |
| 70 | I had neither enough |
| 71 | documentation nor experience in writing interrupt driven device |
| 72 | drivers. |
| 73 | .Pp |
| 74 | The device can operate at four different |
| 75 | .Em resolutions : |
| 76 | 100, 200, |
| 77 | 300 and 400dpi. |
| 78 | It produces a simple bitmap with the most significant |
| 79 | bit at the left side. |
| 80 | The driver can optionally output the famous and |
| 81 | likely simple portable bitmap file format |
| 82 | .Xr pbm 5 |
| 83 | by Jef Poskanzer. |
| 84 | Thus the scans can easily processed by any graphic package around |
| 85 | .Xr ( xpaint 1 , |
| 86 | .Xr xv 1 , |
| 87 | .Xr xli 1 |
| 88 | only to name some of them ...). In |
| 89 | .Em raw |
| 90 | mode a |
| 91 | bit which is set means a black pixel because the scanner detects black |
| 92 | points on white paper. |
| 93 | On the other hand, because pnm format describes |
| 94 | intensities of electron beams in video screens a set bit in |
| 95 | .Em pbm |
| 96 | mode means a white pixel. |
| 97 | .Pp |
| 98 | The |
| 99 | .Em width |
| 100 | of the output bitmap is fixed as given by the |
| 101 | resolution value. |
| 102 | However, the |
| 103 | .Em height |
| 104 | of the bitmap must be |
| 105 | supplied in |
| 106 | .Em pnm |
| 107 | mode since the driver must know at what time the |
| 108 | .Sq end-of-file |
| 109 | shall be reached. |
| 110 | With this feature you are able to |
| 111 | directly copy the scanner output into a pbm file with |
| 112 | .Xr cat 1 . |
| 113 | Of course you can obtain a similar effect by using |
| 114 | .Xr dd 1 |
| 115 | with the driver in |
| 116 | .Em raw |
| 117 | mode. |
| 118 | .Pp |
| 119 | The |
| 120 | .Em graymap |
| 121 | output mode is not yet implemented into the driver. |
| 122 | It is even questionable if external programs would not do this job |
| 123 | better thereby not counting to the size of the kernel. |
| 124 | Even though, I |
| 125 | do not know of tools which produce a graymap from a halftone bitmap. |
| 126 | .Pp |
| 127 | The ioctl requests that are served by |
| 128 | .Nm |
| 129 | are listed below. |
| 130 | There is a utility, called |
| 131 | .Xr sgsc 1 , |
| 132 | that provides access to these |
| 133 | requests from within shell. |
| 134 | .Bl -tag -width Ds |
| 135 | .It Dv GSC_SRES Vt int |
| 136 | Set the |
| 137 | .Em resolution |
| 138 | value. |
| 139 | If this call is made after the first |
| 140 | read access to the device there will be no effect unless the device is |
| 141 | closed and opened again. |
| 142 | .It Dv GSC_GRES Vt int |
| 143 | Get current resolution in dots per inch (dpi). |
| 144 | .It Dv GSC_SRESSW Vt void |
| 145 | Set resolution value from selector switch. |
| 146 | The driver must be in an |
| 147 | open though untouched state otherwise the request will fail and |
| 148 | .Xr errno 2 |
| 149 | is set to |
| 150 | .Er EBUSY . |
| 151 | .It Dv GSC_SWIDTH Vt int |
| 152 | Set the |
| 153 | .Em width |
| 154 | of the bitmap. |
| 155 | Actually, this is an alternative |
| 156 | way of setting the resolution, since any allowed resolution matches |
| 157 | exactly one width. |
| 158 | Allowed are listed in the table below. |
| 159 | .Bl -tag -width resolution -compact -offset indent |
| 160 | .It resolution |
| 161 | width |
| 162 | .It 100 dpi |
| 163 | 424 pixels |
| 164 | .It 200 dpi |
| 165 | 840 pixels |
| 166 | .It 300 dpi |
| 167 | 1264 pixels |
| 168 | .It 400 dpi |
| 169 | 1648 pixels |
| 170 | .It ? |
| 171 | 1696 pixels |
| 172 | .It ? |
| 173 | 2544 pixels |
| 174 | .It ? |
| 175 | 3648 pixels |
| 176 | .El |
| 177 | .Pp |
| 178 | Values which are not reported in the above table will cause the ioctl |
| 179 | call to fail with |
| 180 | .Xr errno 2 |
| 181 | set to |
| 182 | .Er EINVAL . |
| 183 | .Pp |
| 184 | As you can see, there are width values > 1696. |
| 185 | This does, however, not |
| 186 | mean that you can obtain scanned lines longer than the width of your |
| 187 | scanner or by higher resolutions. |
| 188 | Actually, the resolution is selected |
| 189 | by only by the hardware switch. |
| 190 | Any line that is longer than what is |
| 191 | defined for the actual resolution will be undefined (usually white) on |
| 192 | the right part that is exceeding the standard line. |
| 193 | .It Dv GSC_GWIDTH Vt int |
| 194 | Get current width of the bitmap in pixels. |
| 195 | .It Dv GSC_SHEIGHT Vt int |
| 196 | Set the |
| 197 | .Em height |
| 198 | of the bitmap in |
| 199 | .Em pnm |
| 200 | mode. |
| 201 | This is actually |
| 202 | a limit on the amount of lines scannable after the first read |
| 203 | operation. |
| 204 | When the limit is reached read will return 0. However, the |
| 205 | device is turned off only when a close is performed (either |
| 206 | explicitly or implicitly on exit of the calling process). |
| 207 | .It Dv GSC_GHEIGHT Vt int |
| 208 | Get the current height of the bitmap. |
| 209 | .It Dv GSC_SBLEN Vt int |
| 210 | Set the length of the buffer used internally to do the DMA transfer. |
| 211 | The buffer length is supplied in lines of the bitmap. |
| 212 | Since the buffer |
| 213 | size limit is (currently) 0x3000 bytes the maximum number of lines |
| 214 | allowed will vary with the width of each line. |
| 215 | This upper limit is |
| 216 | checked before it overwrites the current value and passes an |
| 217 | .Er ENOMEM |
| 218 | in the |
| 219 | .Xr errno 2 |
| 220 | variable. |
| 221 | However, since the bitmap width can change |
| 222 | after a buffer length was selected a read request may fail with |
| 223 | .Er ENOMEM |
| 224 | if the buffer length turns out too high. |
| 225 | It is generally wise to |
| 226 | choose long buffers rather than go save in order to obtain better |
| 227 | output. |
| 228 | .It Dv GSC_GBLEN Vt int |
| 229 | Get the current buffer length in lines. |
| 230 | .It Dv GSC_SBTIME Vt int |
| 231 | Set the timeout for the completion of reading one buffer. |
| 232 | Since a |
| 233 | handy scanner is a human/computer interface timeout values are usually |
| 234 | higher than those of a flat scanner. |
| 235 | Default is 15 seconds. |
| 236 | After |
| 237 | timeout is reached the read operation will fail with |
| 238 | .Er EBUSY . |
| 239 | Note that |
| 240 | the timeout timer starts anew for each buffer to be read and thus does |
| 241 | not cause you to scan faster for longer images. |
| 242 | BLEN/BTIME is similar |
| 243 | as MIN/TIME in |
| 244 | .Xr termios 4 . |
| 245 | .It Dv GSC_GBTIME Vt int |
| 246 | Get the current buffer timeout. |
| 247 | .El |
| 248 | .Pp |
| 249 | All ioctl requests that modify a parameter except |
| 250 | .Dv GSC_SBTIME |
| 251 | do not |
| 252 | have an effect on an ongoing scan process, i.e. after the first read |
| 253 | request that follows open. |
| 254 | You must close the device and open it again |
| 255 | for the new selections to take effect. |
| 256 | Consequently, the selections |
| 257 | are not reset when you close or open the device. |
| 258 | .Pp |
| 259 | Similarly, requests that read a value do not report the value that is |
| 260 | used for the ongoing scan process. |
| 261 | The values needed during the scan |
| 262 | process are saved when it starts and thus are not accessed by ioctl |
| 263 | requests. |
| 264 | .Pp |
| 265 | The BTIME value does, however, have an immediate effect on the ongoing |
| 266 | scan. |
| 267 | Thus the timeout can for example be set to long until the user |
| 268 | starts scanning. It can then be set to a short amount to react |
| 269 | (nearly) immediately when the user stops. |
| 270 | Note that the user should be |
| 271 | left time to at least fill one buffer without having to haste. |
| 272 | .Pp |
| 273 | Note that the |
| 274 | .Em pbm |
| 275 | versus |
| 276 | .Em raw |
| 277 | mode selection is done by the |
| 278 | minor number not by ioctl requests. |
| 279 | In |
| 280 | .Em raw |
| 281 | mode the selected |
| 282 | height of the bitmap will have no effect. |
| 283 | .Sh FILES |
| 284 | .Bl -tag -width /dev/gsc0pd |
| 285 | .It Pa /dev/gsc0 |
| 286 | device node for |
| 287 | .Em raw |
| 288 | output, has minor number 0. |
| 289 | .It Pa /dev/gsc0d |
| 290 | device node for |
| 291 | .Em raw |
| 292 | output emitting |
| 293 | .Em debug |
| 294 | messages if the |
| 295 | GSCDEBUG option was given at compile time, has minor number 32. |
| 296 | .It Pa /dev/gsc0p |
| 297 | device node for output in |
| 298 | .Em pbm |
| 299 | file format, has minor number 8. |
| 300 | .It Pa /dev/gsc0pd |
| 301 | device node for |
| 302 | .Em pbm |
| 303 | and |
| 304 | .Em debug |
| 305 | mode, has minor number 40. |
| 306 | .El |
| 307 | .Sh EXAMPLES |
| 308 | .Bd -literal -offset indent |
| 309 | dd if=/dev/gsc0 of=rawfile bs=(width/8) count=(height) |
| 310 | |
| 311 | cat /dev/gsc0p > pbmfile |
| 312 | .Ed |
| 313 | .Sh DIAGNOSTICS |
| 314 | .Bl -tag -width Cd |
| 315 | .It GSCDEBUG |
| 316 | When you define this name as an `option' in the kernel configuration |
| 317 | you can get debug output if you access the driver with a minor number |
| 318 | whose debug bit (i.e. bit 5 out of 7) is set. |
| 319 | .El |
| 320 | .Sh SEE ALSO |
| 321 | .Xr cat 1 , |
| 322 | .Xr dd 1 , |
| 323 | .Xr pbmtopgm 1 Pq Pa pkgsrc/graphics/netpbm , |
| 324 | .Xr sgsc 1 , |
| 325 | .Xr close 2 , |
| 326 | .Xr intro 2 , |
| 327 | .Xr ioctl 2 , |
| 328 | .Xr open 2 , |
| 329 | .Xr read 2 , |
| 330 | .Xr termios 4 , |
| 331 | .Xr pbm 5 Pq Pa pkgsrc/graphics/netpbm , |
| 332 | .Xr pnm 5 Pq Pa pkgsrc/graphics/netpbm |
| 333 | .Sh AUTHORS |
| 334 | .An Gunther Schadow Aq gusw@fub46.zedat.fu-berlin.de |
| 335 | .Sh BUGS |
| 336 | Even though the scanner device has a little switch by which you should |
| 337 | be able to select one of the four resolution modes, I could not yet |
| 338 | determine how to read its status. |
| 339 | Unless this is not fixed the driver |
| 340 | depends on the value passed by means of |
| 341 | .Xr ioctl 2 |
| 342 | which need not match |
| 343 | what is selected by the hardware. |