1<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>ioctl FE_GET_INFO</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"><link rel="home" href="index.html" title="LINUX MEDIA INFRASTRUCTURE API"><link rel="up" href="frontend_fcalls.html" title="Frontend Function Calls"><link rel="prev" href="frontend_f_close.html" title="DVB frontend close()"><link rel="next" href="FE_READ_STATUS.html" title="ioctl FE_READ_STATUS"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">ioctl FE_GET_INFO</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="frontend_f_close.html">Prev</a> </td><th width="60%" align="center">Frontend Function Calls</th><td width="20%" align="right"> <a accesskey="n" href="FE_READ_STATUS.html">Next</a></td></tr></table><hr></div><div class="refentry"><a name="FE_GET_INFO"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>FE_GET_INFO — Query DVB frontend capabilities and returns information about 2 the front-end. This call only requires read-only access to the device</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">ioctl</b>(</code></td><td>int <var class="pdparam">fd</var>, </td></tr><tr><td> </td><td>int <var class="pdparam">request</var>, </td></tr><tr><td> </td><td>struct dvb_frontend_info *<var class="pdparam">argp</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="id-1.5.5.12.4.4"></a><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>fd</code></em></span></dt><dd><p>File descriptor returned by <a class="link" href="frontend_f_open.html" title="DVB frontend open()"><code class="function">open()</code></a>.</p></dd><dt><span class="term"><em class="parameter"><code>request</code></em></span></dt><dd><p>FE_GET_INFO</p></dd><dt><span class="term"><em class="parameter"><code>argp</code></em></span></dt><dd><p>pointer to struct struct <a class="link" href="FE_GET_INFO.html#dvb-frontend-info" title="Table 9.17. struct dvb_frontend_info">dvb_frontend_info</a></p></dd></dl></div></div><div class="refsect1"><a name="id-1.5.5.12.4.5"></a><h2>Description</h2><p>All DVB frontend devices support the 3<code class="constant">FE_GET_INFO</code> ioctl. It is used to identify 4kernel devices compatible with this specification and to obtain 5information about driver and hardware capabilities. The ioctl takes a 6pointer to dvb_frontend_info which is filled by the driver. When the 7driver is not compatible with this specification the ioctl returns an error. 8</p><p>RETURN VALUE</p><p>On success <span class="returnvalue">0</span> is returned, on error <span class="returnvalue">-1</span> and the <code class="varname">errno</code> variable is set appropriately. The generic error codes are described at the <a class="link" href="gen_errors.html#gen-errors" title="Table 17.1. Generic error codes">Generic Error Codes</a> chapter.</p><div class="table"><a name="dvb-frontend-info"></a><p class="title"><b>Table 9.17. struct <span class="structname">dvb_frontend_info</span></b></p><div class="table-contents"><table summary="struct dvb_frontend_info" width="100%" border="0"><colgroup><col class="c1"><col class="c2"><col class="c3"></colgroup><tbody valign="top"><tr><td valign="top">char</td><td valign="top">name[128]</td><td valign="top">Name of the frontend</td></tr><tr><td valign="top">fe_type_t</td><td valign="top">type</td><td valign="top"><span class="bold"><strong>DEPRECATED</strong></span>. DVBv3 type. Should not be used on modern programs, as a 9 frontend may have more than one type. So, the DVBv5 API should 10 be used instead to enumerate and select the frontend type.</td></tr><tr><td valign="top">uint32_t</td><td valign="top">frequency_min</td><td valign="top">Minimal frequency supported by the frontend</td></tr><tr><td valign="top">uint32_t</td><td valign="top">frequency_max</td><td valign="top">Maximal frequency supported by the frontend</td></tr><tr><td valign="top">uint32_t</td><td valign="top">frequency_stepsize</td><td valign="top">Frequency step - all frequencies are multiple of this value</td></tr><tr><td valign="top">uint32_t</td><td valign="top">frequency_tolerance</td><td valign="top">Tolerance of the frequency</td></tr><tr><td valign="top">uint32_t</td><td valign="top">symbol_rate_min</td><td valign="top">Minimal symbol rate (for Cable/Satellite systems), in bauds</td></tr><tr><td valign="top">uint32_t</td><td valign="top">symbol_rate_max</td><td valign="top">Maximal symbol rate (for Cable/Satellite systems), in bauds</td></tr><tr><td valign="top">uint32_t</td><td valign="top">symbol_rate_tolerance</td><td valign="top">Maximal symbol rate tolerance, in ppm</td></tr><tr><td valign="top">uint32_t</td><td valign="top">notifier_delay</td><td valign="top"><span class="bold"><strong>DEPRECATED</strong></span>. Not used by any driver.</td></tr><tr><td valign="top">enum <a class="link" href="FE_GET_INFO.html#fe-caps" title="Table 9.18. enum fe_caps">fe_caps</a></td><td valign="top">caps</td><td valign="top">Capabilities supported by the frontend</td></tr></tbody></table></div></div><br class="table-break"><p>NOTE: The frequencies are specified in Hz for Terrestrial and Cable 11 systems. They're specified in kHz for Satellite systems</p></div><div class="refsect1"><a name="fe-caps-t"></a><h2>frontend capabilities</h2><p>Capabilities describe what a frontend can do. Some capabilities are 12 supported only on some specific frontend types.</p><div class="table"><a name="fe-caps"></a><p class="title"><b>Table 9.18. enum fe_caps</b></p><div class="table-contents"><table summary="enum fe_caps" width="100%" border="0"><colgroup><col class="c1"><col class="c2"></colgroup><thead><tr><th>ID</th><th>Description</th></tr></thead><tbody valign="top"><tr><td valign="top"><a name="FE-IS-STUPID"></a><code class="constant">FE_IS_STUPID</code></td><td valign="top">There's something wrong at the frontend, and it can't 13 report its capabilities</td></tr><tr><td valign="top"><a name="FE-CAN-INVERSION-AUTO"></a><code class="constant">FE_CAN_INVERSION_AUTO</code></td><td valign="top">The frontend is capable of auto-detecting inversion</td></tr><tr><td valign="top"><a name="FE-CAN-FEC-1-2"></a><code class="constant">FE_CAN_FEC_1_2</code></td><td valign="top">The frontend supports FEC 1/2</td></tr><tr><td valign="top"><a name="FE-CAN-FEC-2-3"></a><code class="constant">FE_CAN_FEC_2_3</code></td><td valign="top">The frontend supports FEC 2/3</td></tr><tr><td valign="top"><a name="FE-CAN-FEC-3-4"></a><code class="constant">FE_CAN_FEC_3_4</code></td><td valign="top">The frontend supports FEC 3/4</td></tr><tr><td valign="top"><a name="FE-CAN-FEC-4-5"></a><code class="constant">FE_CAN_FEC_4_5</code></td><td valign="top">The frontend supports FEC 4/5</td></tr><tr><td valign="top"><a name="FE-CAN-FEC-5-6"></a><code class="constant">FE_CAN_FEC_5_6</code></td><td valign="top">The frontend supports FEC 5/6</td></tr><tr><td valign="top"><a name="FE-CAN-FEC-6-7"></a><code class="constant">FE_CAN_FEC_6_7</code></td><td valign="top">The frontend supports FEC 6/7</td></tr><tr><td valign="top"><a name="FE-CAN-FEC-7-8"></a><code class="constant">FE_CAN_FEC_7_8</code></td><td valign="top">The frontend supports FEC 7/8</td></tr><tr><td valign="top"><a name="FE-CAN-FEC-8-9"></a><code class="constant">FE_CAN_FEC_8_9</code></td><td valign="top">The frontend supports FEC 8/9</td></tr><tr><td valign="top"><a name="FE-CAN-FEC-AUTO"></a><code class="constant">FE_CAN_FEC_AUTO</code></td><td valign="top">The frontend can autodetect FEC.</td></tr><tr><td valign="top"><a name="FE-CAN-QPSK"></a><code class="constant">FE_CAN_QPSK</code></td><td valign="top">The frontend supports QPSK modulation</td></tr><tr><td valign="top"><a name="FE-CAN-QAM-16"></a><code class="constant">FE_CAN_QAM_16</code></td><td valign="top">The frontend supports 16-QAM modulation</td></tr><tr><td valign="top"><a name="FE-CAN-QAM-32"></a><code class="constant">FE_CAN_QAM_32</code></td><td valign="top">The frontend supports 32-QAM modulation</td></tr><tr><td valign="top"><a name="FE-CAN-QAM-64"></a><code class="constant">FE_CAN_QAM_64</code></td><td valign="top">The frontend supports 64-QAM modulation</td></tr><tr><td valign="top"><a name="FE-CAN-QAM-128"></a><code class="constant">FE_CAN_QAM_128</code></td><td valign="top">The frontend supports 128-QAM modulation</td></tr><tr><td valign="top"><a name="FE-CAN-QAM-256"></a><code class="constant">FE_CAN_QAM_256</code></td><td valign="top">The frontend supports 256-QAM modulation</td></tr><tr><td valign="top"><a name="FE-CAN-QAM-AUTO"></a><code class="constant">FE_CAN_QAM_AUTO</code></td><td valign="top">The frontend can autodetect modulation</td></tr><tr><td valign="top"><a name="FE-CAN-TRANSMISSION-MODE-AUTO"></a><code class="constant">FE_CAN_TRANSMISSION_MODE_AUTO</code></td><td valign="top">The frontend can autodetect the transmission mode</td></tr><tr><td valign="top"><a name="FE-CAN-BANDWIDTH-AUTO"></a><code class="constant">FE_CAN_BANDWIDTH_AUTO</code></td><td valign="top">The frontend can autodetect the bandwidth</td></tr><tr><td valign="top"><a name="FE-CAN-GUARD-INTERVAL-AUTO"></a><code class="constant">FE_CAN_GUARD_INTERVAL_AUTO</code></td><td valign="top">The frontend can autodetect the guard interval</td></tr><tr><td valign="top"><a name="FE-CAN-HIERARCHY-AUTO"></a><code class="constant">FE_CAN_HIERARCHY_AUTO</code></td><td valign="top">The frontend can autodetect hierarch</td></tr><tr><td valign="top"><a name="FE-CAN-8VSB"></a><code class="constant">FE_CAN_8VSB</code></td><td valign="top">The frontend supports 8-VSB modulation</td></tr><tr><td valign="top"><a name="FE-CAN-16VSB"></a><code class="constant">FE_CAN_16VSB</code></td><td valign="top">The frontend supports 16-VSB modulation</td></tr><tr><td valign="top"><a name="FE-HAS-EXTENDED-CAPS"></a><code class="constant">FE_HAS_EXTENDED_CAPS</code></td><td valign="top">Currently, unused</td></tr><tr><td valign="top"><a name="FE-CAN-MULTISTREAM"></a><code class="constant">FE_CAN_MULTISTREAM</code></td><td valign="top">The frontend supports multistream filtering</td></tr><tr><td valign="top"><a name="FE-CAN-TURBO-FEC"></a><code class="constant">FE_CAN_TURBO_FEC</code></td><td valign="top">The frontend supports turbo FEC modulation</td></tr><tr><td valign="top"><a name="FE-CAN-2G-MODULATION"></a><code class="constant">FE_CAN_2G_MODULATION</code></td><td valign="top">The frontend supports "2nd generation modulation" (DVB-S2/T2)></td></tr><tr><td valign="top"><a name="FE-NEEDS-BENDING"></a><code class="constant">FE_NEEDS_BENDING</code></td><td valign="top">Not supported anymore, don't use it</td></tr><tr><td valign="top"><a name="FE-CAN-RECOVER"></a><code class="constant">FE_CAN_RECOVER</code></td><td valign="top">The frontend can recover from a cable unplug automatically</td></tr><tr><td valign="top"><a name="FE-CAN-MUTE-TS"></a><code class="constant">FE_CAN_MUTE_TS</code></td><td valign="top">The frontend can stop spurious TS data output</td></tr></tbody></table></div></div><br class="table-break"></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="frontend_f_close.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="frontend_fcalls.html">Up</a></td><td width="40%" 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