📄 lp.c
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<!doctype html public "-//W3C//DTD HTML 3.2//EN"><html><head><title>Linux/kernel/chr_drv/lp.c</title><base href="http://oldlinux.org/lxr/http/"></head><body bgcolor=white><div align=center> [<b><i>source navigation</i></b>] [<a href="diff/kernel/chr_drv/lp.c?v=0.97">diff markup</a>] [<a href="ident?v=0.97">identifier search</a>] [<a href="search?v=0.97">freetext search</a>] [<a href="find?v=0.97">file search</a>]</div><h1 align=center> <a href="http:/"> Oldlinux</a> <a href="http:blurb.html"> Cross Reference</a><br> <a href="source/?v=0.97">Linux</a>/<a href="source/kernel/?v=0.97">kernel</a>/<a href="source/kernel/chr_drv/?v=0.97">chr_drv</a>/<a href="source/kernel/chr_drv/lp.c?v=0.97">lp.c</a></h1><div align=center> <b>Version:</b> [<a href="source/kernel/chr_drv/lp.c?v=1.0">1.0</a>] [<a href="source/kernel/chr_drv/lp.c?v=0.99.11">0.99.11</a>] [<a href="source/kernel/chr_drv/lp.c?v=0.99">0.99</a>] [<a href="source/kernel/chr_drv/lp.c?v=0.98">0.98</a>] [<b><i>0.97</i></b>] [<a href="source/kernel/chr_drv/lp.c?v=0.96a">0.96a</a>] [<a href="source/kernel/chr_drv/lp.c?v=0.95">0.95</a>] [<a href="source/kernel/chr_drv/lp.c?v=0.12">0.12</a>] [<a href="source/kernel/chr_drv/lp.c">0.11</a>] [<a href="source/kernel/chr_drv/lp.c?v=0.01">0.01</a>] <br> <b>Architecture:</b> [<b><i>i386</i></b>] <br></div><hr><pre> <a name=L1 href="source/kernel/chr_drv/lp.c?v=0.97#L1">1</a> <b><i>/*</i></b> <a name=L2 href="source/kernel/chr_drv/lp.c?v=0.97#L2">2</a> <b><i> $Header: /usr/src/linux/kernel/chr_drv/lp.c,v 1.9 1992/01/06 16:11:19</i></b> <a name=L3 href="source/kernel/chr_drv/lp.c?v=0.97#L3">3</a> <b><i> james_r_wiegand Exp james_r_wiegand $</i></b> <a name=L4 href="source/kernel/chr_drv/lp.c?v=0.97#L4">4</a> <b><i>*/</i></b> <a name=L5 href="source/kernel/chr_drv/lp.c?v=0.97#L5">5</a> <a name=L6 href="source/kernel/chr_drv/lp.c?v=0.97#L6">6</a> <b><i>/*</i></b> <a name=L7 href="source/kernel/chr_drv/lp.c?v=0.97#L7">7</a> <b><i> * Edited by Linus - cleaner interface etc. Still not using interrupts, so</i></b> <a name=L8 href="source/kernel/chr_drv/lp.c?v=0.97#L8">8</a> <b><i> * it eats more resources than necessary, but it was easy to code this way...</i></b> <a name=L9 href="source/kernel/chr_drv/lp.c?v=0.97#L9">9</a> <b><i> */</i></b> <a name=L10 href="source/kernel/chr_drv/lp.c?v=0.97#L10">10</a> <a name=L11 href="source/kernel/chr_drv/lp.c?v=0.97#L11">11</a> #include <linux/sched.h> <a name=L12 href="source/kernel/chr_drv/lp.c?v=0.97#L12">12</a> #include <linux/lp.h> <a name=L13 href="source/kernel/chr_drv/lp.c?v=0.97#L13">13</a> <a name=L14 href="source/kernel/chr_drv/lp.c?v=0.97#L14">14</a> static int <a href="ident?v=0.97;i=lp_reset">lp_reset</a>(int minor) <a name=L15 href="source/kernel/chr_drv/lp.c?v=0.97#L15">15</a> { <a name=L16 href="source/kernel/chr_drv/lp.c?v=0.97#L16">16</a> int testvalue; <a name=L17 href="source/kernel/chr_drv/lp.c?v=0.97#L17">17</a> <a name=L18 href="source/kernel/chr_drv/lp.c?v=0.97#L18">18</a> <b><i>/* reset value */</i></b> <a name=L19 href="source/kernel/chr_drv/lp.c?v=0.97#L19">19</a> <a href="ident?v=0.97;i=outb">outb</a>(0, <a href="ident?v=0.97;i=LP_B">LP_B</a>(minor)+2); <a name=L20 href="source/kernel/chr_drv/lp.c?v=0.97#L20">20</a> for (testvalue = 0 ; testvalue < <a href="ident?v=0.97;i=LP_DELAY">LP_DELAY</a> ; testvalue++) <a name=L21 href="source/kernel/chr_drv/lp.c?v=0.97#L21">21</a> ; <a name=L22 href="source/kernel/chr_drv/lp.c?v=0.97#L22">22</a> <a href="ident?v=0.97;i=outb">outb</a>(<a href="ident?v=0.97;i=LP_PSELECP">LP_PSELECP</a> | <a href="ident?v=0.97;i=LP_PINITP">LP_PINITP</a>, <a href="ident?v=0.97;i=LP_B">LP_B</a>(minor)+2); <a name=L23 href="source/kernel/chr_drv/lp.c?v=0.97#L23">23</a> return <a href="ident?v=0.97;i=LP_S">LP_S</a>(minor); <a name=L24 href="source/kernel/chr_drv/lp.c?v=0.97#L24">24</a> } <a name=L25 href="source/kernel/chr_drv/lp.c?v=0.97#L25">25</a> <a name=L26 href="source/kernel/chr_drv/lp.c?v=0.97#L26">26</a> static int <a href="ident?v=0.97;i=lp_char">lp_char</a>(char lpchar, int minor) <a name=L27 href="source/kernel/chr_drv/lp.c?v=0.97#L27">27</a> { <a name=L28 href="source/kernel/chr_drv/lp.c?v=0.97#L28">28</a> int retval = 0; <a name=L29 href="source/kernel/chr_drv/lp.c?v=0.97#L29">29</a> unsigned long <a href="ident?v=0.97;i=count">count</a> = 0; <a name=L30 href="source/kernel/chr_drv/lp.c?v=0.97#L30">30</a> <a name=L31 href="source/kernel/chr_drv/lp.c?v=0.97#L31">31</a> <a href="ident?v=0.97;i=outb">outb</a>(lpchar, <a href="ident?v=0.97;i=LP_B">LP_B</a>(minor)); <a name=L32 href="source/kernel/chr_drv/lp.c?v=0.97#L32">32</a> do { <a name=L33 href="source/kernel/chr_drv/lp.c?v=0.97#L33">33</a> retval = <a href="ident?v=0.97;i=LP_S">LP_S</a>(minor); <a name=L34 href="source/kernel/chr_drv/lp.c?v=0.97#L34">34</a> <a href="ident?v=0.97;i=schedule">schedule</a>(); <a name=L35 href="source/kernel/chr_drv/lp.c?v=0.97#L35">35</a> <a href="ident?v=0.97;i=count">count</a> ++; <a name=L36 href="source/kernel/chr_drv/lp.c?v=0.97#L36">36</a> } while(!(retval & <a href="ident?v=0.97;i=LP_PBUSY">LP_PBUSY</a>) && <a href="ident?v=0.97;i=count">count</a> < <a href="ident?v=0.97;i=LP_TIMEOUT">LP_TIMEOUT</a>); <a name=L37 href="source/kernel/chr_drv/lp.c?v=0.97#L37">37</a> if (<a href="ident?v=0.97;i=count">count</a> == <a href="ident?v=0.97;i=LP_TIMEOUT">LP_TIMEOUT</a>) { <a name=L38 href="source/kernel/chr_drv/lp.c?v=0.97#L38">38</a> <a href="ident?v=0.97;i=printk">printk</a>(<i>"lp%d timeout\n\r"</i>, minor); <a name=L39 href="source/kernel/chr_drv/lp.c?v=0.97#L39">39</a> return 0; <a name=L40 href="source/kernel/chr_drv/lp.c?v=0.97#L40">40</a> } <a name=L41 href="source/kernel/chr_drv/lp.c?v=0.97#L41">41</a> <b><i>/* control port pr_table[0]+2 take strobe high */</i></b> <a name=L42 href="source/kernel/chr_drv/lp.c?v=0.97#L42">42</a> <a href="ident?v=0.97;i=outb">outb</a>(( <a href="ident?v=0.97;i=LP_PSELECP">LP_PSELECP</a> | <a href="ident?v=0.97;i=LP_PINITP">LP_PINITP</a> | <a href="ident?v=0.97;i=LP_PSTROBE">LP_PSTROBE</a> ), ( <a href="ident?v=0.97;i=LP_B">LP_B</a>( minor ) + 2 )); <a name=L43 href="source/kernel/chr_drv/lp.c?v=0.97#L43">43</a> <b><i>/* take strobe low */</i></b> <a name=L44 href="source/kernel/chr_drv/lp.c?v=0.97#L44">44</a> <a href="ident?v=0.97;i=outb">outb</a>(( <a href="ident?v=0.97;i=LP_PSELECP">LP_PSELECP</a> | <a href="ident?v=0.97;i=LP_PINITP">LP_PINITP</a> ), ( <a href="ident?v=0.97;i=LP_B">LP_B</a>( minor ) + 2 )); <a name=L45 href="source/kernel/chr_drv/lp.c?v=0.97#L45">45</a> <b><i>/* get something meaningful for return value */</i></b> <a name=L46 href="source/kernel/chr_drv/lp.c?v=0.97#L46">46</a> return <a href="ident?v=0.97;i=LP_S">LP_S</a>(minor); <a name=L47 href="source/kernel/chr_drv/lp.c?v=0.97#L47">47</a> } <a name=L48 href="source/kernel/chr_drv/lp.c?v=0.97#L48">48</a> <a name=L49 href="source/kernel/chr_drv/lp.c?v=0.97#L49">49</a> static int <a href="ident?v=0.97;i=lp_write">lp_write</a>(struct <a href="ident?v=0.97;i=inode">inode</a> * <a href="ident?v=0.97;i=inode">inode</a>, struct <a href="ident?v=0.97;i=file">file</a> * <a href="ident?v=0.97;i=file">file</a>, char * <a href="ident?v=0.97;i=buf">buf</a>, int <a href="ident?v=0.97;i=count">count</a>) <a name=L50 href="source/kernel/chr_drv/lp.c?v=0.97#L50">50</a> { <a name=L51 href="source/kernel/chr_drv/lp.c?v=0.97#L51">51</a> int retval; <a name=L52 href="source/kernel/chr_drv/lp.c?v=0.97#L52">52</a> unsigned int minor = <a href="ident?v=0.97;i=MINOR">MINOR</a>(<a href="ident?v=0.97;i=inode">inode</a>->i_rdev); <a name=L53 href="source/kernel/chr_drv/lp.c?v=0.97#L53">53</a> char c, *temp = <a href="ident?v=0.97;i=buf">buf</a>; <a name=L54 href="source/kernel/chr_drv/lp.c?v=0.97#L54">54</a> <a name=L55 href="source/kernel/chr_drv/lp.c?v=0.97#L55">55</a> temp = <a href="ident?v=0.97;i=buf">buf</a>; <a name=L56 href="source/kernel/chr_drv/lp.c?v=0.97#L56">56</a> while (<a href="ident?v=0.97;i=count">count</a> > 0) { <a name=L57 href="source/kernel/chr_drv/lp.c?v=0.97#L57">57</a> c = <a href="ident?v=0.97;i=get_fs_byte">get_fs_byte</a>(temp++); <a name=L58 href="source/kernel/chr_drv/lp.c?v=0.97#L58">58</a> retval = <a href="ident?v=0.97;i=lp_char">lp_char</a>(c, minor); <a name=L59 href="source/kernel/chr_drv/lp.c?v=0.97#L59">59</a> <a href="ident?v=0.97;i=count">count</a>--; <a name=L60 href="source/kernel/chr_drv/lp.c?v=0.97#L60">60</a> if (retval & <a href="ident?v=0.97;i=LP_POUTPA">LP_POUTPA</a>) { <a name=L61 href="source/kernel/chr_drv/lp.c?v=0.97#L61">61</a> <a href="ident?v=0.97;i=LP_F">LP_F</a>(minor) |= <a href="ident?v=0.97;i=LP_NOPA">LP_NOPA</a>; <a name=L62 href="source/kernel/chr_drv/lp.c?v=0.97#L62">62</a> return temp-<a href="ident?v=0.97;i=buf">buf</a>?temp-<a href="ident?v=0.97;i=buf">buf</a>:-<a href="ident?v=0.97;i=ENOSPC">ENOSPC</a>; <a name=L63 href="source/kernel/chr_drv/lp.c?v=0.97#L63">63</a> } else <a name=L64 href="source/kernel/chr_drv/lp.c?v=0.97#L64">64</a> <a href="ident?v=0.97;i=LP_F">LP_F</a>(minor) &= ~LP_NOPA; <a name=L65 href="source/kernel/chr_drv/lp.c?v=0.97#L65">65</a> <a name=L66 href="source/kernel/chr_drv/lp.c?v=0.97#L66">66</a> if (!(retval & <a href="ident?v=0.97;i=LP_PSELECD">LP_PSELECD</a>)) {⌨️ 快捷键说明
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