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authorMauro Carvalho Chehab <mchehab@redhat.com>2009-09-13 21:16:04 -0400
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-09-18 22:47:55 -0400
commit8e080c2e6cadada82a6b520e0c23a1cb974822d5 (patch)
tree991450ff1abba98e5313906478c33816a202ccab /Documentation/DocBook/dvb/frontend.xml
parentf4e96deb4513d044653027d4921fd7592195503a (diff)
V4L/DVB (12761): DocBook: add media API specs
The V4L and DVB API's are there for a long time. however, up to now, no efforts were done to merge them to kernel DocBook. This patch adds the current versions of the specs as an unique compendium. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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1<title>DVB Frontend API</title>
2
3<para>The DVB frontend device controls the tuner and DVB demodulator
4hardware. It can be accessed through <emphasis
5role="tt">/dev/dvb/adapter0/frontend0</emphasis>. Data types and and
6ioctl definitions can be accessed by including <emphasis
7role="tt">linux/dvb/frontend.h</emphasis> in your application.</para>
8
9<para>DVB frontends come in three varieties: DVB-S (satellite), DVB-C
10(cable) and DVB-T (terrestrial). Transmission via the internet (DVB-IP)
11is not yet handled by this API but a future extension is possible. For
12DVB-S the frontend device also supports satellite equipment control
13(SEC) via DiSEqC and V-SEC protocols. The DiSEqC (digital SEC)
14specification is available from Eutelsat <emphasis
15role="tt">http://www.eutelsat.org/</emphasis>.</para>
16
17<para>Note that the DVB API may also be used for MPEG decoder-only PCI
18cards, in which case there exists no frontend device.</para>
19
20<section id="frontend_types">
21<title>Frontend Data Types</title>
22
23<section id="frontend_type">
24<title>frontend type</title>
25
26<para>For historical reasons frontend types are named after the type of modulation used in
27transmission.</para>
28<programlisting>
29 typedef enum fe_type {
30 FE_QPSK, /&#x22C6; DVB-S &#x22C6;/
31 FE_QAM, /&#x22C6; DVB-C &#x22C6;/
32 FE_OFDM /&#x22C6; DVB-T &#x22C6;/
33 } fe_type_t;
34</programlisting>
35
36</section>
37
38<section id="frontend_caps">
39<title>frontend capabilities</title>
40
41<para>Capabilities describe what a frontend can do. Some capabilities can only be supported for
42a specific frontend type.</para>
43<programlisting>
44 typedef enum fe_caps {
45 FE_IS_STUPID = 0,
46 FE_CAN_INVERSION_AUTO = 0x1,
47 FE_CAN_FEC_1_2 = 0x2,
48 FE_CAN_FEC_2_3 = 0x4,
49 FE_CAN_FEC_3_4 = 0x8,
50 FE_CAN_FEC_4_5 = 0x10,
51 FE_CAN_FEC_5_6 = 0x20,
52 FE_CAN_FEC_6_7 = 0x40,
53 FE_CAN_FEC_7_8 = 0x80,
54 FE_CAN_FEC_8_9 = 0x100,
55 FE_CAN_FEC_AUTO = 0x200,
56 FE_CAN_QPSK = 0x400,
57 FE_CAN_QAM_16 = 0x800,
58 FE_CAN_QAM_32 = 0x1000,
59 FE_CAN_QAM_64 = 0x2000,
60 FE_CAN_QAM_128 = 0x4000,
61 FE_CAN_QAM_256 = 0x8000,
62 FE_CAN_QAM_AUTO = 0x10000,
63 FE_CAN_TRANSMISSION_MODE_AUTO = 0x20000,
64 FE_CAN_BANDWIDTH_AUTO = 0x40000,
65 FE_CAN_GUARD_INTERVAL_AUTO = 0x80000,
66 FE_CAN_HIERARCHY_AUTO = 0x100000,
67 FE_CAN_MUTE_TS = 0x80000000,
68 FE_CAN_CLEAN_SETUP = 0x40000000
69 } fe_caps_t;
70</programlisting>
71</section>
72
73<section id="frontend_info">
74<title>frontend information</title>
75
76<para>Information about the frontend ca be queried with FE_GET_INFO.</para>
77
78<programlisting>
79 struct dvb_frontend_info {
80 char name[128];
81 fe_type_t type;
82 uint32_t frequency_min;
83 uint32_t frequency_max;
84 uint32_t frequency_stepsize;
85 uint32_t frequency_tolerance;
86 uint32_t symbol_rate_min;
87 uint32_t symbol_rate_max;
88 uint32_t symbol_rate_tolerance; /&#x22C6; ppm &#x22C6;/
89 uint32_t notifier_delay; /&#x22C6; ms &#x22C6;/
90 fe_caps_t caps;
91 };
92</programlisting>
93</section>
94
95<section id="frontend_diseqc">
96<title>diseqc master command</title>
97
98<para>A message sent from the frontend to DiSEqC capable equipment.</para>
99<programlisting>
100 struct dvb_diseqc_master_cmd {
101 uint8_t msg [6]; /&#x22C6; { framing, address, command, data[3] } &#x22C6;/
102 uint8_t msg_len; /&#x22C6; valid values are 3...6 &#x22C6;/
103 };
104</programlisting>
105</section>
106<section role="subsection">
107<title>diseqc slave reply</title>
108
109<para>A reply to the frontend from DiSEqC 2.0 capable equipment.</para>
110<programlisting>
111 struct dvb_diseqc_slave_reply {
112 uint8_t msg [4]; /&#x22C6; { framing, data [3] } &#x22C6;/
113 uint8_t msg_len; /&#x22C6; valid values are 0...4, 0 means no msg &#x22C6;/
114 int timeout; /&#x22C6; return from ioctl after timeout ms with &#x22C6;/
115 }; /&#x22C6; errorcode when no message was received &#x22C6;/
116</programlisting>
117</section>
118
119<section id="frontend_diseqc_slave_reply">
120<title>diseqc slave reply</title>
121<para>The voltage is usually used with non-DiSEqC capable LNBs to switch the polarzation
122(horizontal/vertical). When using DiSEqC epuipment this voltage has to be switched
123consistently to the DiSEqC commands as described in the DiSEqC spec.</para>
124<programlisting>
125 typedef enum fe_sec_voltage {
126 SEC_VOLTAGE_13,
127 SEC_VOLTAGE_18
128 } fe_sec_voltage_t;
129</programlisting>
130</section>
131
132<section id="frontend_sec_tone">
133<title>SEC continuous tone</title>
134
135<para>The continous 22KHz tone is usually used with non-DiSEqC capable LNBs to switch the
136high/low band of a dual-band LNB. When using DiSEqC epuipment this voltage has to
137be switched consistently to the DiSEqC commands as described in the DiSEqC
138spec.</para>
139<programlisting>
140 typedef enum fe_sec_tone_mode {
141 SEC_TONE_ON,
142 SEC_TONE_OFF
143 } fe_sec_tone_mode_t;
144</programlisting>
145</section>
146
147<section id="frontend_sec_burst">
148<title>SEC tone burst</title>
149
150<para>The 22KHz tone burst is usually used with non-DiSEqC capable switches to select
151between two connected LNBs/satellites. When using DiSEqC epuipment this voltage has to
152be switched consistently to the DiSEqC commands as described in the DiSEqC
153spec.</para>
154<programlisting>
155 typedef enum fe_sec_mini_cmd {
156 SEC_MINI_A,
157 SEC_MINI_B
158 } fe_sec_mini_cmd_t;
159</programlisting>
160
161<para></para>
162</section>
163
164<section id="frontend_status">
165<title>frontend status</title>
166<para>Several functions of the frontend device use the fe_status data type defined
167by</para>
168<programlisting>
169 typedef enum fe_status {
170 FE_HAS_SIGNAL = 0x01, /&#x22C6; found something above the noise level &#x22C6;/
171 FE_HAS_CARRIER = 0x02, /&#x22C6; found a DVB signal &#x22C6;/
172 FE_HAS_VITERBI = 0x04, /&#x22C6; FEC is stable &#x22C6;/
173 FE_HAS_SYNC = 0x08, /&#x22C6; found sync bytes &#x22C6;/
174 FE_HAS_LOCK = 0x10, /&#x22C6; everything's working... &#x22C6;/
175 FE_TIMEDOUT = 0x20, /&#x22C6; no lock within the last ~2 seconds &#x22C6;/
176 FE_REINIT = 0x40 /&#x22C6; frontend was reinitialized, &#x22C6;/
177 } fe_status_t; /&#x22C6; application is recommned to reset &#x22C6;/
178</programlisting>
179<para>to indicate the current state and/or state changes of the frontend hardware.
180</para>
181
182</section>
183
184<section id="frontend_params">
185<title>frontend parameters</title>
186<para>The kind of parameters passed to the frontend device for tuning depend on
187the kind of hardware you are using. All kinds of parameters are combined as an
188union in the FrontendParameters structure:</para>
189<programlisting>
190 struct dvb_frontend_parameters {
191 uint32_t frequency; /&#x22C6; (absolute) frequency in Hz for QAM/OFDM &#x22C6;/
192 /&#x22C6; intermediate frequency in kHz for QPSK &#x22C6;/
193 fe_spectral_inversion_t inversion;
194 union {
195 struct dvb_qpsk_parameters qpsk;
196 struct dvb_qam_parameters qam;
197 struct dvb_ofdm_parameters ofdm;
198 } u;
199 };
200</programlisting>
201<para>For satellite QPSK frontends you have to use the <constant>QPSKParameters</constant> member defined by</para>
202<programlisting>
203 struct dvb_qpsk_parameters {
204 uint32_t symbol_rate; /&#x22C6; symbol rate in Symbols per second &#x22C6;/
205 fe_code_rate_t fec_inner; /&#x22C6; forward error correction (see above) &#x22C6;/
206 };
207</programlisting>
208<para>for cable QAM frontend you use the <constant>QAMParameters</constant> structure</para>
209<programlisting>
210 struct dvb_qam_parameters {
211 uint32_t symbol_rate; /&#x22C6; symbol rate in Symbols per second &#x22C6;/
212 fe_code_rate_t fec_inner; /&#x22C6; forward error correction (see above) &#x22C6;/
213 fe_modulation_t modulation; /&#x22C6; modulation type (see above) &#x22C6;/
214 };
215</programlisting>
216<para>DVB-T frontends are supported by the <constant>OFDMParamters</constant> structure
217</para>
218<programlisting>
219 struct dvb_ofdm_parameters {
220 fe_bandwidth_t bandwidth;
221 fe_code_rate_t code_rate_HP; /&#x22C6; high priority stream code rate &#x22C6;/
222 fe_code_rate_t code_rate_LP; /&#x22C6; low priority stream code rate &#x22C6;/
223 fe_modulation_t constellation; /&#x22C6; modulation type (see above) &#x22C6;/
224 fe_transmit_mode_t transmission_mode;
225 fe_guard_interval_t guard_interval;
226 fe_hierarchy_t hierarchy_information;
227 };
228</programlisting>
229<para>In the case of QPSK frontends the <constant>Frequency</constant> field specifies the intermediate
230frequency, i.e. the offset which is effectively added to the local oscillator frequency (LOF) of
231the LNB. The intermediate frequency has to be specified in units of kHz. For QAM and
232OFDM frontends the Frequency specifies the absolute frequency and is given in
233Hz.
234</para>
235<para>The Inversion field can take one of these values:
236</para>
237<programlisting>
238 typedef enum fe_spectral_inversion {
239 INVERSION_OFF,
240 INVERSION_ON,
241 INVERSION_AUTO
242 } fe_spectral_inversion_t;
243</programlisting>
244<para>It indicates if spectral inversion should be presumed or not. In the automatic setting
245(<constant>INVERSION_AUTO</constant>) the hardware will try to figure out the correct setting by
246itself.
247</para>
248<para>The possible values for the <constant>FEC_inner</constant> field are
249</para>
250<programlisting>
251 typedef enum fe_code_rate {
252 FEC_NONE = 0,
253 FEC_1_2,
254 FEC_2_3,
255 FEC_3_4,
256 FEC_4_5,
257 FEC_5_6,
258 FEC_6_7,
259 FEC_7_8,
260 FEC_8_9,
261 FEC_AUTO
262 } fe_code_rate_t;
263</programlisting>
264<para>which correspond to error correction rates of 1/2, 2/3, etc., no error correction or auto
265detection.
266</para>
267<para>For cable and terrestrial frontends (QAM and OFDM) one also has to specify the quadrature
268modulation mode which can be one of the following:
269</para>
270<programlisting>
271 typedef enum fe_modulation {
272 QPSK,
273 QAM_16,
274 QAM_32,
275 QAM_64,
276 QAM_128,
277 QAM_256,
278 QAM_AUTO
279 } fe_modulation_t;
280</programlisting>
281<para>Finally, there are several more parameters for OFDM:
282</para>
283<programlisting>
284 typedef enum fe_transmit_mode {
285 TRANSMISSION_MODE_2K,
286 TRANSMISSION_MODE_8K,
287 TRANSMISSION_MODE_AUTO
288 } fe_transmit_mode_t;
289</programlisting>
290 <programlisting>
291 typedef enum fe_bandwidth {
292 BANDWIDTH_8_MHZ,
293 BANDWIDTH_7_MHZ,
294 BANDWIDTH_6_MHZ,
295 BANDWIDTH_AUTO
296 } fe_bandwidth_t;
297</programlisting>
298 <programlisting>
299 typedef enum fe_guard_interval {
300 GUARD_INTERVAL_1_32,
301 GUARD_INTERVAL_1_16,
302 GUARD_INTERVAL_1_8,
303 GUARD_INTERVAL_1_4,
304 GUARD_INTERVAL_AUTO
305 } fe_guard_interval_t;
306</programlisting>
307 <programlisting>
308 typedef enum fe_hierarchy {
309 HIERARCHY_NONE,
310 HIERARCHY_1,
311 HIERARCHY_2,
312 HIERARCHY_4,
313 HIERARCHY_AUTO
314 } fe_hierarchy_t;
315</programlisting>
316
317</section>
318
319<section id="frontend_events">
320<title>frontend events</title>
321 <programlisting>
322 struct dvb_frontend_event {
323 fe_status_t status;
324 struct dvb_frontend_parameters parameters;
325 };
326</programlisting>
327 </section>
328</section>
329
330
331<section id="frontend_fcalls">
332<title>Frontend Function Calls</title>
333
334<section id="frontend_f_open">
335<title>open()</title>
336<para>DESCRIPTION</para>
337<informaltable><tgroup cols="1"><tbody><row>
338<entry align="char">
339<para>This system call opens a named frontend device (/dev/dvb/adapter0/frontend0)
340 for subsequent use. Usually the first thing to do after a successful open is to
341 find out the frontend type with FE_GET_INFO.</para>
342<para>The device can be opened in read-only mode, which only allows monitoring of
343 device status and statistics, or read/write mode, which allows any kind of use
344 (e.g. performing tuning operations.)
345</para>
346<para>In a system with multiple front-ends, it is usually the case that multiple devices
347 cannot be open in read/write mode simultaneously. As long as a front-end
348 device is opened in read/write mode, other open() calls in read/write mode will
349 either fail or block, depending on whether non-blocking or blocking mode was
350 specified. A front-end device opened in blocking mode can later be put into
351 non-blocking mode (and vice versa) using the F_SETFL command of the fcntl
352 system call. This is a standard system call, documented in the Linux manual
353 page for fcntl. When an open() call has succeeded, the device will be ready
354 for use in the specified mode. This implies that the corresponding hardware is
355 powered up, and that other front-ends may have been powered down to make
356 that possible.</para>
357</entry>
358 </row></tbody></tgroup></informaltable>
359
360<para>SYNOPSIS</para>
361<informaltable><tgroup cols="1"><tbody><row><entry
362 align="char">
363<para>int open(const char &#x22C6;deviceName, int flags);</para>
364</entry>
365 </row></tbody></tgroup></informaltable>
366<para>PARAMETERS
367</para>
368<informaltable><tgroup cols="2"><tbody><row><entry
369 align="char">
370<para>const char
371 *deviceName</para>
372</entry><entry
373 align="char">
374<para>Name of specific video device.</para>
375</entry>
376 </row><row><entry
377 align="char">
378<para>int flags</para>
379</entry><entry
380 align="char">
381<para>A bit-wise OR of the following flags:</para>
382</entry>
383 </row><row><entry
384 align="char">
385</entry><entry
386 align="char">
387<para>O_RDONLY read-only access</para>
388</entry>
389 </row><row><entry
390 align="char">
391</entry><entry
392 align="char">
393<para>O_RDWR read/write access</para>
394</entry>
395 </row><row><entry
396 align="char">
397</entry><entry
398 align="char">
399<para>O_NONBLOCK open in non-blocking mode</para>
400</entry>
401 </row><row><entry
402 align="char">
403</entry><entry
404 align="char">
405<para>(blocking mode is the default)</para>
406</entry>
407 </row></tbody></tgroup></informaltable>
408<para>ERRORS
409</para>
410<informaltable><tgroup cols="2"><tbody><row><entry
411 align="char">
412<para>ENODEV</para>
413</entry><entry
414 align="char">
415<para>Device driver not loaded/available.</para>
416</entry>
417 </row><row><entry
418 align="char">
419<para>EINTERNAL</para>
420</entry><entry
421 align="char">
422<para>Internal error.</para>
423</entry>
424 </row><row><entry
425 align="char">
426<para>EBUSY</para>
427</entry><entry
428 align="char">
429<para>Device or resource busy.</para>
430</entry>
431 </row><row><entry
432 align="char">
433<para>EINVAL</para>
434</entry><entry
435 align="char">
436<para>Invalid argument.</para>
437</entry>
438 </row></tbody></tgroup></informaltable>
439</section>
440
441<section id="frontend_f_close">
442<title>close()</title>
443<para>DESCRIPTION
444</para>
445<informaltable><tgroup cols="1"><tbody><row><entry
446 align="char">
447<para>This system call closes a previously opened front-end device. After closing
448 a front-end device, its corresponding hardware might be powered down
449 automatically.</para>
450</entry>
451 </row></tbody></tgroup></informaltable>
452<para>SYNOPSIS
453</para>
454<informaltable><tgroup cols="1"><tbody><row><entry
455 align="char">
456<para>int close(int fd);</para>
457</entry>
458 </row></tbody></tgroup></informaltable>
459<para>PARAMETERS
460</para>
461<informaltable><tgroup cols="2"><tbody><row><entry
462 align="char">
463<para>int fd</para>
464</entry><entry
465 align="char">
466<para>File descriptor returned by a previous call to open().</para>
467</entry>
468 </row></tbody></tgroup></informaltable>
469<para>ERRORS
470</para>
471<informaltable><tgroup cols="2"><tbody><row><entry
472 align="char">
473<para>EBADF</para>
474</entry><entry
475 align="char">
476<para>fd is not a valid open file descriptor.</para>
477</entry>
478 </row></tbody></tgroup></informaltable>
479</section>
480
481<section id="frontend_read_status">
482<title>FE_READ_STATUS</title>
483<para>DESCRIPTION
484</para>
485<informaltable><tgroup cols="1"><tbody><row><entry
486 align="char">
487<para>This ioctl call returns status information about the front-end. This call only
488 requires read-only access to the device.</para>
489</entry>
490 </row></tbody></tgroup></informaltable>
491<para>SYNOPSIS
492</para>
493<informaltable><tgroup cols="1"><tbody><row><entry
494 align="char">
495<para>int ioctl(int fd, int request = FE_READ_STATUS,
496 fe_status_t &#x22C6;status);</para>
497</entry>
498 </row></tbody></tgroup></informaltable>
499<para>PARAMETERS
500</para>
501
502<informaltable><tgroup cols="2"><tbody><row><entry
503 align="char">
504<para>int fd</para>
505</entry><entry
506 align="char">
507<para>File descriptor returned by a previous call to open().</para>
508</entry>
509 </row><row><entry
510 align="char">
511<para>int request</para>
512</entry><entry
513 align="char">
514<para>Equals FE_READ_STATUS for this command.</para>
515</entry>
516 </row><row><entry
517 align="char">
518<para>struct fe_status_t
519 *status</para>
520</entry><entry
521 align="char">
522<para>Points to the location where the front-end status word is
523 to be stored.</para>
524</entry>
525 </row></tbody></tgroup></informaltable>
526<para>ERRORS
527</para>
528<informaltable><tgroup cols="2"><tbody><row><entry
529 align="char">
530<para>EBADF</para>
531</entry><entry
532 align="char">
533<para>fd is not a valid open file descriptor.</para>
534</entry>
535 </row><row><entry
536 align="char">
537<para>EFAULT</para>
538</entry><entry
539 align="char">
540<para>status points to invalid address.</para>
541</entry>
542 </row></tbody></tgroup></informaltable>
543</section>
544
545<section id="frontend_read_ber">
546<title>FE_READ_BER</title>
547<para>DESCRIPTION
548</para>
549<informaltable><tgroup cols="1"><tbody><row><entry
550 align="char">
551<para>This ioctl call returns the bit error rate for the signal currently
552 received/demodulated by the front-end. For this command, read-only access to
553 the device is sufficient.</para>
554</entry>
555 </row></tbody></tgroup></informaltable>
556<para>SYNOPSIS
557</para>
558<informaltable><tgroup cols="1"><tbody><row><entry
559 align="char">
560<para>int ioctl(int fd, int request = FE_READ_BER,
561 uint32_t &#x22C6;ber);</para>
562</entry>
563 </row></tbody></tgroup></informaltable>
564<para>PARAMETERS
565</para>
566<informaltable><tgroup cols="2"><tbody><row><entry
567 align="char">
568<para>int fd</para>
569</entry><entry
570 align="char">
571<para>File descriptor returned by a previous call to open().</para>
572</entry>
573 </row><row><entry
574 align="char">
575<para>int request</para>
576</entry><entry
577 align="char">
578<para>Equals FE_READ_BER for this command.</para>
579</entry>
580 </row><row><entry
581 align="char">
582<para>uint32_t *ber</para>
583</entry><entry
584 align="char">
585<para>The bit error rate is stored into *ber.</para>
586</entry>
587 </row></tbody></tgroup></informaltable>
588<para>ERRORS
589</para>
590<informaltable><tgroup cols="2"><tbody><row><entry
591 align="char">
592<para>EBADF</para>
593</entry><entry
594 align="char">
595<para>fd is not a valid open file descriptor.</para>
596</entry>
597 </row><row><entry
598 align="char">
599<para>EFAULT</para>
600</entry><entry
601 align="char">
602<para>ber points to invalid address.</para>
603</entry>
604 </row><row><entry
605 align="char">
606<para>ENOSIGNAL</para>
607</entry><entry
608 align="char">
609<para>There is no signal, thus no meaningful bit error rate. Also
610 returned if the front-end is not turned on.</para>
611</entry>
612 </row><row><entry
613 align="char">
614<para>ENOSYS</para>
615</entry><entry
616 align="char">
617<para>Function not available for this device.</para>
618</entry>
619 </row></tbody></tgroup></informaltable>
620</section>
621
622<section id="frontend_read_snr">
623<title>FE_READ_SNR</title>
624
625<para>DESCRIPTION
626</para>
627<informaltable><tgroup cols="1"><tbody><row><entry
628 align="char">
629<para>This ioctl call returns the signal-to-noise ratio for the signal currently received
630 by the front-end. For this command, read-only access to the device is sufficient.</para>
631</entry>
632 </row></tbody></tgroup></informaltable>
633<para>SYNOPSIS
634</para>
635<informaltable><tgroup cols="1"><tbody><row><entry
636 align="char">
637<para>int ioctl(int fd, int request = FE_READ_SNR, int16_t
638 &#x22C6;snr);</para>
639</entry>
640 </row></tbody></tgroup></informaltable>
641<para>PARAMETERS
642</para>
643<informaltable><tgroup cols="2"><tbody><row><entry
644 align="char">
645<para>int fd</para>
646</entry><entry
647 align="char">
648<para>File descriptor returned by a previous call to open().</para>
649</entry>
650 </row><row><entry
651 align="char">
652<para>int request</para>
653</entry><entry
654 align="char">
655<para>Equals FE_READ_SNR for this command.</para>
656</entry>
657 </row><row><entry
658 align="char">
659<para>int16_t *snr</para>
660</entry><entry
661 align="char">
662<para>The signal-to-noise ratio is stored into *snr.</para>
663</entry>
664 </row></tbody></tgroup></informaltable>
665
666<para>ERRORS
667</para>
668<informaltable><tgroup cols="2"><tbody><row><entry
669 align="char">
670<para>EBADF</para>
671</entry><entry
672 align="char">
673<para>fd is not a valid open file descriptor.</para>
674</entry>
675 </row><row><entry
676 align="char">
677<para>EFAULT</para>
678</entry><entry
679 align="char">
680<para>snr points to invalid address.</para>
681</entry>
682 </row><row><entry
683 align="char">
684<para>ENOSIGNAL</para>
685</entry><entry
686 align="char">
687<para>There is no signal, thus no meaningful signal strength
688 value. Also returned if front-end is not turned on.</para>
689</entry>
690 </row><row><entry
691 align="char">
692<para>ENOSYS</para>
693</entry><entry
694 align="char">
695<para>Function not available for this device.</para>
696</entry>
697 </row></tbody></tgroup></informaltable>
698</section>
699
700<section id="frontend_read_signal_strength">
701<title>FE_READ_SIGNAL_STRENGTH</title>
702<para>DESCRIPTION
703</para>
704<informaltable><tgroup cols="1"><tbody><row><entry
705 align="char">
706<para>This ioctl call returns the signal strength value for the signal currently received
707 by the front-end. For this command, read-only access to the device is sufficient.</para>
708</entry>
709 </row></tbody></tgroup></informaltable>
710<para>SYNOPSIS
711</para>
712<informaltable><tgroup cols="1"><tbody><row><entry
713 align="char">
714<para>int ioctl( int fd, int request =
715 FE_READ_SIGNAL_STRENGTH, int16_t &#x22C6;strength);</para>
716</entry>
717 </row></tbody></tgroup></informaltable>
718
719<para>PARAMETERS
720</para>
721<informaltable><tgroup cols="2"><tbody><row><entry
722 align="char">
723<para>int fd</para>
724</entry><entry
725 align="char">
726<para>File descriptor returned by a previous call to open().</para>
727</entry>
728 </row><row><entry
729 align="char">
730<para>int request</para>
731</entry><entry
732 align="char">
733<para>Equals FE_READ_SIGNAL_STRENGTH for this
734 command.</para>
735</entry>
736 </row><row><entry
737 align="char">
738<para>int16_t *strength</para>
739</entry><entry
740 align="char">
741<para>The signal strength value is stored into *strength.</para>
742</entry>
743 </row></tbody></tgroup></informaltable>
744<para>ERRORS
745</para>
746<informaltable><tgroup cols="2"><tbody><row><entry
747 align="char">
748<para>EBADF</para>
749</entry><entry
750 align="char">
751<para>fd is not a valid open file descriptor.</para>
752</entry>
753 </row><row><entry
754 align="char">
755<para>EFAULT</para>
756</entry><entry
757 align="char">
758<para>status points to invalid address.</para>
759</entry>
760 </row><row><entry
761 align="char">
762<para>ENOSIGNAL</para>
763</entry><entry
764 align="char">
765<para>There is no signal, thus no meaningful signal strength
766 value. Also returned if front-end is not turned on.</para>
767</entry>
768 </row><row><entry
769 align="char">
770<para>ENOSYS</para>
771</entry><entry
772 align="char">
773<para>Function not available for this device.</para>
774</entry>
775 </row></tbody></tgroup></informaltable>
776</section>
777
778<section id="frontend_read_ub">
779<title>FE_READ_UNCORRECTED_BLOCKS</title>
780<para>DESCRIPTION
781</para>
782<informaltable><tgroup cols="1"><tbody><row><entry
783 align="char">
784<para>This ioctl call returns the number of uncorrected blocks detected by the device
785 driver during its lifetime. For meaningful measurements, the increment in block
786 count during a specific time interval should be calculated. For this command,
787 read-only access to the device is sufficient.</para>
788</entry>
789 </row><row><entry
790 align="char">
791<para>Note that the counter will wrap to zero after its maximum count has been
792 reached.</para>
793</entry>
794 </row></tbody></tgroup></informaltable>
795<para>SYNOPSIS
796</para>
797<informaltable><tgroup cols="1"><tbody><row><entry
798 align="char">
799<para>int ioctl( int fd, int request =
800 FE_READ_UNCORRECTED_BLOCKS, uint32_t &#x22C6;ublocks);</para>
801</entry>
802 </row></tbody></tgroup></informaltable>
803<para>PARAMETERS
804</para>
805<informaltable><tgroup cols="2"><tbody><row><entry
806 align="char">
807<para>int fd</para>
808</entry><entry
809 align="char">
810<para>File descriptor returned by a previous call to open().</para>
811</entry>
812 </row><row><entry
813 align="char">
814<para>int request</para>
815</entry><entry
816 align="char">
817<para>Equals FE_READ_UNCORRECTED_BLOCKS for this
818 command.</para>
819</entry>
820 </row><row><entry
821 align="char">
822<para>uint32_t *ublocks</para>
823</entry><entry
824 align="char">
825<para>The total number of uncorrected blocks seen by the driver
826 so far.</para>
827</entry>
828 </row></tbody></tgroup></informaltable>
829<para>ERRORS
830</para>
831<informaltable><tgroup cols="2"><tbody><row><entry
832 align="char">
833<para>EBADF</para>
834</entry><entry
835 align="char">
836<para>fd is not a valid open file descriptor.</para>
837</entry>
838 </row><row><entry
839 align="char">
840<para>EFAULT</para>
841</entry><entry
842 align="char">
843<para>ublocks points to invalid address.</para>
844</entry>
845 </row><row><entry
846 align="char">
847<para>ENOSYS</para>
848</entry><entry
849 align="char">
850<para>Function not available for this device.</para>
851</entry>
852 </row></tbody></tgroup></informaltable>
853</section>
854
855<section id="frontend_set_fe">
856<title>FE_SET_FRONTEND</title>
857<para>DESCRIPTION
858</para>
859<informaltable><tgroup cols="1"><tbody><row><entry
860 align="char">
861<para>This ioctl call starts a tuning operation using specified parameters. The result
862 of this call will be successful if the parameters were valid and the tuning could
863 be initiated. The result of the tuning operation in itself, however, will arrive
864 asynchronously as an event (see documentation for FE_GET_EVENT and
865 FrontendEvent.) If a new FE_SET_FRONTEND operation is initiated before
866 the previous one was completed, the previous operation will be aborted in favor
867 of the new one. This command requires read/write access to the device.</para>
868</entry>
869 </row></tbody></tgroup></informaltable>
870
871<para>SYNOPSIS
872</para>
873<informaltable><tgroup cols="1"><tbody><row><entry
874 align="char">
875<para>int ioctl(int fd, int request = FE_SET_FRONTEND,
876 struct dvb_frontend_parameters &#x22C6;p);</para>
877</entry>
878 </row></tbody></tgroup></informaltable>
879<para>PARAMETERS
880</para>
881<informaltable><tgroup cols="2"><tbody><row><entry
882 align="char">
883<para>int fd</para>
884</entry><entry
885 align="char">
886<para>File descriptor returned by a previous call to open().</para>
887</entry>
888 </row><row><entry
889 align="char">
890<para>int request</para>
891</entry><entry
892 align="char">
893<para>Equals FE_SET_FRONTEND for this command.</para>
894</entry>
895 </row><row><entry
896 align="char">
897<para>struct
898 dvb_frontend_parameters
899 *p</para>
900</entry><entry
901 align="char">
902<para>Points to parameters for tuning operation.</para>
903</entry>
904 </row></tbody></tgroup></informaltable>
905<para>ERRORS
906</para>
907<informaltable><tgroup cols="2"><tbody><row><entry
908 align="char">
909<para>EBADF</para>
910</entry><entry
911 align="char">
912<para>fd is not a valid open file descriptor.</para>
913</entry>
914 </row><row><entry
915 align="char">
916<para>EFAULT</para>
917</entry><entry
918 align="char">
919<para>p points to invalid address.</para>
920</entry>
921 </row><row><entry
922 align="char">
923<para>EINVAL</para>
924</entry><entry
925 align="char">
926<para>Maximum supported symbol rate reached.</para>
927</entry>
928</row></tbody></tgroup></informaltable>
929</section>
930
931<section id="frontend_get_fe">
932<title>FE_GET_FRONTEND</title>
933<para>DESCRIPTION
934</para>
935<informaltable><tgroup cols="1"><tbody><row><entry
936 align="char">
937<para>This ioctl call queries the currently effective frontend parameters. For this
938 command, read-only access to the device is sufficient.</para>
939</entry>
940 </row></tbody></tgroup></informaltable>
941
942<para>SYNOPSIS
943</para>
944<informaltable><tgroup cols="1"><tbody><row><entry
945 align="char">
946<para>int ioctl(int fd, int request = FE_GET_FRONTEND,
947 struct dvb_frontend_parameters &#x22C6;p);</para>
948</entry>
949 </row></tbody></tgroup></informaltable>
950
951<para>PARAMETERS
952</para>
953<informaltable><tgroup cols="2"><tbody><row><entry
954 align="char">
955<para>int fd</para>
956</entry><entry
957 align="char">
958<para>File descriptor returned by a previous call to open().</para>
959</entry>
960 </row><row><entry
961 align="char">
962<para>int request</para>
963</entry><entry
964 align="char">
965<para>Equals FE_SET_FRONTEND for this command.</para>
966</entry>
967 </row><row><entry
968 align="char">
969<para>struct
970 dvb_frontend_parameters
971 *p</para>
972</entry><entry
973 align="char">
974<para>Points to parameters for tuning operation.</para>
975</entry>
976 </row></tbody></tgroup></informaltable>
977
978<para>ERRORS
979</para>
980
981<informaltable><tgroup cols="2"><tbody><row><entry
982 align="char">
983<para>EBADF</para>
984</entry><entry
985 align="char">
986<para>fd is not a valid open file descriptor.</para>
987</entry>
988 </row><row><entry
989 align="char">
990<para>EFAULT</para>
991</entry><entry
992 align="char">
993<para>p points to invalid address.</para>
994</entry>
995 </row><row><entry
996 align="char">
997<para>EINVAL</para>
998</entry><entry
999 align="char">
1000<para>Maximum supported symbol rate reached.</para>
1001</entry>
1002 </row></tbody></tgroup></informaltable>
1003
1004</section>
1005
1006<section id="frontend_get_event">
1007<title>FE_GET_EVENT</title>
1008<para>DESCRIPTION
1009</para>
1010<informaltable><tgroup cols="1"><tbody><row><entry
1011 align="char">
1012<para>This ioctl call returns a frontend event if available. If an event is not
1013 available, the behavior depends on whether the device is in blocking or
1014 non-blocking mode. In the latter case, the call fails immediately with errno
1015 set to EWOULDBLOCK. In the former case, the call blocks until an event
1016 becomes available.</para>
1017</entry>
1018 </row><row><entry
1019 align="char">
1020<para>The standard Linux poll() and/or select() system calls can be used with the
1021 device file descriptor to watch for new events. For select(), the file descriptor
1022 should be included in the exceptfds argument, and for poll(), POLLPRI should
1023 be specified as the wake-up condition. Since the event queue allocated is
1024 rather small (room for 8 events), the queue must be serviced regularly to avoid
1025 overflow. If an overflow happens, the oldest event is discarded from the queue,
1026 and an error (EOVERFLOW) occurs the next time the queue is read. After
1027 reporting the error condition in this fashion, subsequent FE_GET_EVENT
1028 calls will return events from the queue as usual.</para>
1029</entry>
1030 </row><row><entry
1031 align="char">
1032<para>For the sake of implementation simplicity, this command requires read/write
1033 access to the device.</para>
1034</entry>
1035 </row></tbody></tgroup></informaltable>
1036
1037<para>SYNOPSIS
1038</para>
1039<informaltable><tgroup cols="1"><tbody><row><entry
1040 align="char">
1041<para>int ioctl(int fd, int request = QPSK_GET_EVENT,
1042 struct dvb_frontend_event &#x22C6;ev);</para>
1043</entry>
1044 </row></tbody></tgroup></informaltable>
1045
1046<para>PARAMETERS
1047</para>
1048<informaltable><tgroup cols="2"><tbody><row><entry
1049 align="char">
1050<para>int fd</para>
1051</entry><entry
1052 align="char">
1053<para>File descriptor returned by a previous call to open().</para>
1054</entry>
1055 </row><row><entry
1056 align="char">
1057<para>int request</para>
1058</entry><entry
1059 align="char">
1060<para>Equals FE_GET_EVENT for this command.</para>
1061</entry>
1062 </row><row><entry
1063 align="char">
1064<para>struct
1065 dvb_frontend_event
1066 *ev</para>
1067</entry><entry
1068 align="char">
1069<para>Points to the location where the event,</para>
1070</entry>
1071 </row><row><entry
1072 align="char">
1073</entry><entry
1074 align="char">
1075<para>if any, is to be stored.</para>
1076</entry>
1077 </row></tbody></tgroup></informaltable>
1078
1079<para>ERRORS
1080</para>
1081<informaltable><tgroup cols="2"><tbody><row><entry
1082 align="char">
1083<para>EBADF</para>
1084</entry><entry
1085 align="char">
1086<para>fd is not a valid open file descriptor.</para>
1087</entry>
1088 </row><row><entry
1089 align="char">
1090<para>EFAULT</para>
1091</entry><entry
1092 align="char">
1093<para>ev points to invalid address.</para>
1094</entry>
1095 </row><row><entry
1096 align="char">
1097<para>EWOULDBLOCK</para>
1098</entry><entry
1099 align="char">
1100<para>There is no event pending, and the device is in
1101 non-blocking mode.</para>
1102</entry>
1103 </row><row><entry
1104 align="char">
1105<para>EOVERFLOW</para>
1106</entry><entry
1107 align="char">
1108</entry>
1109 </row><row><entry
1110 align="char">
1111</entry><entry
1112 align="char">
1113<para>Overflow in event queue - one or more events were lost.</para>
1114</entry>
1115</row></tbody></tgroup></informaltable>
1116</section>
1117
1118<section id="frontend_get_info">
1119<title>FE_GET_INFO</title>
1120<para>DESCRIPTION
1121</para>
1122<informaltable><tgroup cols="1"><tbody><row><entry
1123 align="char">
1124<para>This ioctl call returns information about the front-end. This call only requires
1125 read-only access to the device.</para>
1126</entry>
1127 </row></tbody></tgroup></informaltable>
1128<para>SYNOPSIS
1129</para>
1130
1131<informaltable><tgroup cols="1"><tbody><row><entry
1132 align="char">
1133<para> int ioctl(int fd, int request = FE_GET_INFO, struct
1134 dvb_frontend_info &#x22C6;info);</para>
1135</entry>
1136 </row></tbody></tgroup></informaltable>
1137<para>PARAMETERS
1138</para>
1139
1140<informaltable><tgroup cols="2"><tbody><row><entry
1141 align="char">
1142<para>int fd</para>
1143</entry><entry
1144 align="char">
1145<para>File descriptor returned by a previous call to open().</para>
1146</entry>
1147 </row><row><entry
1148 align="char">
1149<para>int request</para>
1150</entry><entry
1151 align="char">
1152<para>Equals FE_GET_INFO for this command.</para>
1153</entry>
1154 </row><row><entry
1155 align="char">
1156<para>struct
1157 dvb_frontend_info
1158 *info</para>
1159</entry><entry
1160 align="char">
1161<para>Points to the location where the front-end information is
1162 to be stored.</para>
1163</entry>
1164 </row></tbody></tgroup></informaltable>
1165<para>ERRORS
1166</para>
1167<informaltable><tgroup cols="2"><tbody><row><entry
1168 align="char">
1169<para>EBADF</para>
1170</entry><entry
1171 align="char">
1172<para>fd is not a valid open file descriptor.</para>
1173</entry>
1174 </row><row><entry
1175 align="char">
1176<para>EFAULT</para>
1177</entry><entry
1178 align="char">
1179<para>info points to invalid address.</para>
1180</entry>
1181</row></tbody></tgroup></informaltable>
1182</section>
1183
1184<section id="frontend_diseqc_reset_overload">
1185<title>FE_DISEQC_RESET_OVERLOAD</title>
1186<para>DESCRIPTION
1187</para>
1188<informaltable><tgroup cols="1"><tbody><row><entry
1189 align="char">
1190<para>If the bus has been automatically powered off due to power overload, this ioctl
1191 call restores the power to the bus. The call requires read/write access to the
1192 device. This call has no effect if the device is manually powered off. Not all
1193 DVB adapters support this ioctl.</para>
1194</entry>
1195 </row></tbody></tgroup></informaltable>
1196
1197<para>SYNOPSIS
1198</para>
1199<informaltable><tgroup cols="1"><tbody><row><entry
1200 align="char">
1201<para>int ioctl(int fd, int request =
1202 FE_DISEQC_RESET_OVERLOAD);</para>
1203</entry>
1204 </row></tbody></tgroup></informaltable>
1205<para>PARAMETERS
1206</para>
1207<informaltable><tgroup cols="2"><tbody><row><entry
1208 align="char">
1209<para>int fd</para>
1210</entry><entry
1211 align="char">
1212<para>File descriptor returned by a previous call to open().</para>
1213</entry>
1214 </row><row><entry
1215 align="char">
1216<para>int request</para>
1217</entry><entry
1218 align="char">
1219<para>Equals FE_DISEQC_RESET_OVERLOAD for this
1220 command.</para>
1221</entry>
1222 </row></tbody></tgroup></informaltable>
1223
1224<para>ERRORS
1225</para>
1226<informaltable><tgroup cols="2"><tbody><row><entry
1227 align="char">
1228<para>EBADF</para>
1229</entry><entry
1230 align="char">
1231<para>fd is not a valid file descriptor.</para>
1232</entry>
1233 </row><row><entry
1234 align="char">
1235<para>EPERM</para>
1236</entry><entry
1237 align="char">
1238<para>Permission denied (needs read/write access).</para>
1239</entry>
1240 </row><row><entry
1241 align="char">
1242<para>EINTERNAL</para>
1243</entry><entry
1244 align="char">
1245<para>Internal error in the device driver.</para>
1246</entry>
1247</row></tbody></tgroup></informaltable>
1248</section>
1249
1250<section id="frontend_diseqc_send_master_cmd">
1251<title>FE_DISEQC_SEND_MASTER_CMD</title>
1252<para>DESCRIPTION
1253</para>
1254<informaltable><tgroup cols="1"><tbody><row><entry
1255 align="char">
1256<para>This ioctl call is used to send a a DiSEqC command.</para>
1257</entry>
1258 </row></tbody></tgroup></informaltable>
1259<para>SYNOPSIS
1260</para>
1261<informaltable><tgroup cols="1"><tbody><row><entry
1262 align="char">
1263<para>int ioctl(int fd, int request =
1264 FE_DISEQC_SEND_MASTER_CMD, struct
1265 dvb_diseqc_master_cmd &#x22C6;cmd);</para>
1266</entry>
1267 </row></tbody></tgroup></informaltable>
1268
1269<para>PARAMETERS
1270</para>
1271<informaltable><tgroup cols="2"><tbody><row><entry
1272 align="char">
1273<para>int fd</para>
1274</entry><entry
1275 align="char">
1276<para>File descriptor returned by a previous call to open().</para>
1277</entry>
1278 </row><row><entry
1279 align="char">
1280<para>int request</para>
1281</entry><entry
1282 align="char">
1283<para>Equals FE_DISEQC_SEND_MASTER_CMD for this
1284 command.</para>
1285</entry>
1286 </row><row><entry
1287 align="char">
1288<para>struct
1289 dvb_diseqc_master_cmd
1290 *cmd</para>
1291</entry><entry
1292 align="char">
1293<para>Pointer to the command to be transmitted.</para>
1294</entry>
1295 </row></tbody></tgroup></informaltable>
1296
1297<para>ERRORS
1298</para>
1299<informaltable><tgroup cols="2"><tbody><row><entry
1300 align="char">
1301<para>EBADF</para>
1302</entry><entry
1303 align="char">
1304<para>fd is not a valid file descriptor.</para>
1305</entry>
1306 </row><row><entry
1307 align="char">
1308<para>EFAULT</para>
1309</entry><entry
1310 align="char">
1311<para>Seq points to an invalid address.</para>
1312</entry>
1313 </row><row><entry
1314 align="char">
1315<para>EINVAL</para>
1316</entry><entry
1317 align="char">
1318<para>The data structure referred to by seq is invalid in some
1319 way.</para>
1320</entry>
1321 </row><row><entry
1322 align="char">
1323<para>EPERM</para>
1324</entry><entry
1325 align="char">
1326<para>Permission denied (needs read/write access).</para>
1327</entry>
1328 </row><row><entry
1329 align="char">
1330<para>EINTERNAL</para>
1331</entry><entry
1332 align="char">
1333<para>Internal error in the device driver.</para>
1334</entry>
1335</row></tbody></tgroup></informaltable>
1336</section>
1337
1338<section id="frontend_diseqc_recv_slave_reply">
1339<title>FE_DISEQC_RECV_SLAVE_REPLY</title>
1340<para>DESCRIPTION
1341</para>
1342<informaltable><tgroup cols="1"><tbody><row><entry
1343 align="char">
1344<para>This ioctl call is used to receive reply to a DiSEqC 2.0 command.</para>
1345</entry>
1346 </row></tbody></tgroup></informaltable>
1347
1348<para>SYNOPSIS
1349</para>
1350<informaltable><tgroup cols="1"><tbody><row><entry
1351 align="char">
1352<para>int ioctl(int fd, int request =
1353 FE_DISEQC_RECV_SLAVE_REPLY, struct
1354 dvb_diseqc_slave_reply &#x22C6;reply);</para>
1355</entry>
1356 </row></tbody></tgroup></informaltable>
1357
1358<para>PARAMETERS
1359</para>
1360<informaltable><tgroup cols="2"><tbody><row><entry
1361 align="char">
1362<para>int fd</para>
1363</entry><entry
1364 align="char">
1365<para>File descriptor returned by a previous call to open().</para>
1366</entry>
1367 </row><row><entry
1368 align="char">
1369<para>int request</para>
1370</entry><entry
1371 align="char">
1372<para>Equals FE_DISEQC_RECV_SLAVE_REPLY for this
1373 command.</para>
1374</entry>
1375 </row><row><entry
1376 align="char">
1377<para>struct
1378 dvb_diseqc_slave_reply
1379 *reply</para>
1380</entry><entry
1381 align="char">
1382<para>Pointer to the command to be received.</para>
1383</entry>
1384 </row></tbody></tgroup></informaltable>
1385<para>ERRORS
1386</para>
1387<informaltable><tgroup cols="2"><tbody><row><entry
1388 align="char">
1389<para>EBADF</para>
1390</entry><entry
1391 align="char">
1392<para>fd is not a valid file descriptor.</para>
1393</entry>
1394 </row><row><entry
1395 align="char">
1396<para>EFAULT</para>
1397</entry><entry
1398 align="char">
1399<para>Seq points to an invalid address.</para>
1400</entry>
1401 </row><row><entry
1402 align="char">
1403<para>EINVAL</para>
1404</entry><entry
1405 align="char">
1406<para>The data structure referred to by seq is invalid in some
1407 way.</para>
1408</entry>
1409 </row><row><entry
1410 align="char">
1411<para>EPERM</para>
1412</entry><entry
1413 align="char">
1414<para>Permission denied (needs read/write access).</para>
1415</entry>
1416 </row><row><entry
1417 align="char">
1418<para>EINTERNAL</para>
1419</entry><entry
1420 align="char">
1421<para>Internal error in the device driver.</para>
1422</entry>
1423 </row></tbody></tgroup></informaltable>
1424</section>
1425
1426<section id="frontend_diseqc_send_burst">
1427<title>FE_DISEQC_SEND_BURST</title>
1428<para>DESCRIPTION
1429</para>
1430<informaltable><tgroup cols="1"><tbody><row><entry
1431 align="char">
1432<para>This ioctl call is used to send a 22KHz tone burst.</para>
1433</entry>
1434 </row></tbody></tgroup></informaltable>
1435
1436<para>SYNOPSIS
1437</para>
1438<informaltable><tgroup cols="1"><tbody><row><entry
1439 align="char">
1440<para>int ioctl(int fd, int request =
1441 FE_DISEQC_SEND_BURST, fe_sec_mini_cmd_t burst);</para>
1442</entry>
1443 </row></tbody></tgroup></informaltable>
1444
1445<para>PARAMETERS
1446</para>
1447<informaltable><tgroup cols="2"><tbody><row><entry
1448 align="char">
1449<para>int fd</para>
1450</entry><entry
1451 align="char">
1452<para>File descriptor returned by a previous call to open().</para>
1453</entry>
1454 </row><row><entry
1455 align="char">
1456<para>int request</para>
1457</entry><entry
1458 align="char">
1459<para>Equals FE_DISEQC_SEND_BURST for this command.</para>
1460</entry>
1461 </row><row><entry
1462 align="char">
1463<para>fe_sec_mini_cmd_t
1464 burst</para>
1465</entry><entry
1466 align="char">
1467<para>burst A or B.</para>
1468</entry>
1469 </row></tbody></tgroup></informaltable>
1470
1471<para>ERRORS
1472</para>
1473<informaltable><tgroup cols="2"><tbody><row><entry
1474 align="char">
1475<para>EBADF</para>
1476</entry><entry
1477 align="char">
1478<para>fd is not a valid file descriptor.</para>
1479</entry>
1480 </row><row><entry
1481 align="char">
1482<para>EFAULT</para>
1483</entry><entry
1484 align="char">
1485<para>Seq points to an invalid address.</para>
1486</entry>
1487 </row><row><entry
1488 align="char">
1489<para>EINVAL</para>
1490</entry><entry
1491 align="char">
1492<para>The data structure referred to by seq is invalid in some
1493 way.</para>
1494</entry>
1495 </row><row><entry
1496 align="char">
1497<para>EPERM</para>
1498</entry><entry
1499 align="char">
1500<para>Permission denied (needs read/write access).</para>
1501</entry>
1502 </row><row><entry
1503 align="char">
1504<para>EINTERNAL</para>
1505</entry><entry
1506 align="char">
1507<para>Internal error in the device driver.</para>
1508</entry>
1509</row></tbody></tgroup></informaltable>
1510</section>
1511
1512<section id="frontend_set_tone">
1513<title>FE_SET_TONE</title>
1514<para>DESCRIPTION
1515</para>
1516<informaltable><tgroup cols="1"><tbody><row><entry
1517 align="char">
1518<para>This call is used to set the generation of the continuous 22kHz tone. This call
1519 requires read/write permissions.</para>
1520</entry>
1521 </row></tbody></tgroup></informaltable>
1522<para>SYNOPSIS
1523</para>
1524<informaltable><tgroup cols="1"><tbody><row><entry
1525 align="char">
1526<para>int ioctl(int fd, int request = FE_SET_TONE,
1527 fe_sec_tone_mode_t tone);</para>
1528</entry>
1529 </row></tbody></tgroup></informaltable>
1530<para>PARAMETERS
1531</para>
1532<informaltable><tgroup cols="2"><tbody><row><entry
1533 align="char">
1534<para>int fd</para>
1535</entry><entry
1536 align="char">
1537<para>File descriptor returned by a previous call to open().</para>
1538</entry>
1539 </row><row><entry
1540 align="char">
1541<para>int request</para>
1542</entry><entry
1543 align="char">
1544<para>Equals FE_SET_TONE for this command.</para>
1545</entry>
1546 </row><row><entry
1547 align="char">
1548<para>fe_sec_tone_mode_t
1549 tone</para>
1550</entry><entry
1551 align="char">
1552<para>The requested tone generation mode (on/off).</para>
1553</entry>
1554 </row></tbody></tgroup></informaltable>
1555<para>ERRORS
1556</para>
1557<informaltable><tgroup cols="2"><tbody><row><entry
1558 align="char">
1559<para>ENODEV</para>
1560</entry><entry
1561 align="char">
1562<para>Device driver not loaded/available.</para>
1563</entry>
1564 </row><row><entry
1565 align="char">
1566<para>EBUSY</para>
1567</entry><entry
1568 align="char">
1569<para>Device or resource busy.</para>
1570</entry>
1571 </row><row><entry
1572 align="char">
1573<para>EINVAL</para>
1574</entry><entry
1575 align="char">
1576<para>Invalid argument.</para>
1577</entry>
1578 </row><row><entry
1579 align="char">
1580<para>EPERM</para>
1581</entry><entry
1582 align="char">
1583<para>File not opened with read permissions.</para>
1584</entry>
1585 </row><row><entry
1586 align="char">
1587<para>EINTERNAL</para>
1588</entry><entry
1589 align="char">
1590<para>Internal error in the device driver.</para>
1591</entry>
1592</row></tbody></tgroup></informaltable>
1593</section>
1594
1595<section id="fe_set_voltage">
1596<title>FE_SET_VOLTAGE</title>
1597<para>DESCRIPTION
1598</para>
1599<informaltable><tgroup cols="1"><tbody><row><entry
1600 align="char">
1601<para>This call is used to set the bus voltage. This call requires read/write
1602 permissions.</para>
1603</entry>
1604 </row></tbody></tgroup></informaltable>
1605<para>SYNOPSIS
1606</para>
1607<informaltable><tgroup cols="1"><tbody><row><entry
1608 align="char">
1609<para>int ioctl(int fd, int request = FE_SET_VOLTAGE,
1610 fe_sec_voltage_t voltage);</para>
1611</entry>
1612 </row></tbody></tgroup></informaltable>
1613
1614<para>PARAMETERS
1615</para>
1616<informaltable><tgroup cols="2"><tbody><row><entry
1617 align="char">
1618<para>int fd</para>
1619</entry><entry
1620 align="char">
1621<para>File descriptor returned by a previous call to open().</para>
1622</entry>
1623 </row><row><entry
1624 align="char">
1625<para>int request</para>
1626</entry><entry
1627 align="char">
1628<para>Equals FE_SET_VOLTAGE for this command.</para>
1629</entry>
1630 </row><row><entry
1631 align="char">
1632<para>fe_sec_voltage_t
1633 voltage</para>
1634</entry><entry
1635 align="char">
1636<para>The requested bus voltage.</para>
1637</entry>
1638 </row></tbody></tgroup></informaltable>
1639
1640<para>ERRORS
1641</para>
1642<informaltable><tgroup cols="2"><tbody><row><entry
1643 align="char">
1644<para>ENODEV</para>
1645</entry><entry
1646 align="char">
1647<para>Device driver not loaded/available.</para>
1648</entry>
1649 </row><row><entry
1650 align="char">
1651<para>EBUSY</para>
1652</entry><entry
1653 align="char">
1654<para>Device or resource busy.</para>
1655</entry>
1656 </row><row><entry
1657 align="char">
1658<para>EINVAL</para>
1659</entry><entry
1660 align="char">
1661<para>Invalid argument.</para>
1662</entry>
1663 </row><row><entry
1664 align="char">
1665<para>EPERM</para>
1666</entry><entry
1667 align="char">
1668<para>File not opened with read permissions.</para>
1669</entry>
1670 </row><row><entry
1671 align="char">
1672<para>EINTERNAL</para>
1673</entry><entry
1674 align="char">
1675<para>Internal error in the device driver.</para>
1676</entry>
1677 </row></tbody></tgroup></informaltable>
1678</section>
1679
1680<section id="frontend_enable_high_lnb_volt">
1681<title>FE_ENABLE_HIGH_LNB_VOLTAGE</title>
1682<para>DESCRIPTION
1683</para>
1684<informaltable><tgroup cols="1"><tbody><row><entry
1685 align="char">
1686<para>If high != 0 enables slightly higher voltages instead of 13/18V (to compensate
1687 for long cables). This call requires read/write permissions. Not all DVB
1688 adapters support this ioctl.</para>
1689</entry>
1690 </row></tbody></tgroup></informaltable>
1691
1692<para>SYNOPSIS
1693</para>
1694<informaltable><tgroup cols="1"><tbody><row><entry
1695 align="char">
1696<para>int ioctl(int fd, int request =
1697 FE_ENABLE_HIGH_LNB_VOLTAGE, int high);</para>
1698</entry>
1699 </row></tbody></tgroup></informaltable>
1700
1701<para>PARAMETERS
1702</para>
1703<informaltable><tgroup cols="2"><tbody><row><entry
1704 align="char">
1705<para>int fd</para>
1706</entry><entry
1707 align="char">
1708<para>File descriptor returned by a previous call to open().</para>
1709</entry>
1710 </row><row><entry
1711 align="char">
1712<para>int request</para>
1713</entry><entry
1714 align="char">
1715<para>Equals FE_SET_VOLTAGE for this command.</para>
1716</entry>
1717 </row><row><entry
1718 align="char">
1719<para>int high</para>
1720</entry><entry
1721 align="char">
1722<para>The requested bus voltage.</para>
1723</entry>
1724 </row></tbody></tgroup></informaltable>
1725
1726<para>ERRORS
1727</para>
1728<informaltable><tgroup cols="2"><tbody><row><entry
1729 align="char">
1730<para>ENODEV</para>
1731</entry><entry
1732 align="char">
1733<para>Device driver not loaded/available.</para>
1734</entry>
1735 </row><row><entry
1736 align="char">
1737<para>EBUSY</para>
1738</entry><entry
1739 align="char">
1740<para>Device or resource busy.</para>
1741</entry>
1742 </row><row><entry
1743 align="char">
1744<para>EINVAL</para>
1745</entry><entry
1746 align="char">
1747<para>Invalid argument.</para>
1748</entry>
1749 </row><row><entry
1750 align="char">
1751<para>EPERM</para>
1752</entry><entry
1753 align="char">
1754<para>File not opened with read permissions.</para>
1755</entry>
1756 </row><row><entry
1757 align="char">
1758<para>EINTERNAL</para>
1759</entry><entry
1760 align="char">
1761<para>Internal error in the device driver.</para>
1762</entry>
1763 </row></tbody></tgroup></informaltable>
1764</section>
1765</section>
generated by cgit v1.2.2 (git 2.25.0) at 2026-04-26 20:17:42 -0400