The patch number 10581 was added via rjkm
to http://linuxtv.org/hg/v4l-dvb master development tree.
Kernel patches in this development tree may be modified to be backward
compatible with older kernels. Compatibility modifications will be
removed before inclusion into the mainstream Kernel
If anyone has any objections, please let us know by sending a message to:
Linux Media Mailing List <linux-me...@vger.kernel.org>
------
added new API docs
---
dvb-spec/dvbapi/frontend.tex | 612 +++++++++++++++++++++++++++++++++++
1 file changed, 612 insertions(+)
diff -r d55d41fce655 -r da1df54d68c5 dvb-spec/dvbapi/frontend.tex
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/dvb-spec/dvbapi/frontend.tex Sun Sep 16 22:27:38 2001 -0300
@@ -0,0 +1,612 @@
+\devsec{DVB Frontend API}
+
+The DVB frontend device controls the tuner and DVB demodulator hardware.
+It can be accessed through \texttt{/dev/ost/frontend}.
+If you are using \texttt{devfs} you can use \texttt{/dev/dvb/card0/frontend}.
+The frontend device will only be made visible through \texttt{devfs}
+if the corresponding card actually has a frontend. Cards which support
+the DVB API but, e.g., only can play back recordings, will not offer the
+frontend device.
+
+\devsubsec{Frontend Data Types}
+
+\devsubsubsec{frontend status}
+\label{frontendstatus}
+
+Several functions of the frontend device use the feStatus data
+type defined by
+\begin{verbatim}
+typedef uint32_t feStatus;
+\end{verbatim}
+to indicate the current state and/or state changes of
+the frontend hardware.
+
+\noindent
+It can take on the values
+\begin{verbatim}
+#define FE_HAS_POWER 1
+#define FE_HAS_SIGNAL 2
+#define FE_SPECTRUM_INV 4
+#define FE_HAS_LOCK 8
+#define TUNER_HAS_LOCK 128
+\end{verbatim}
+which can be ORed together and have the following meaning:
+
+\medskip
+
+\begin{tabular}{lp{11cm}}
+FE\_HAS\_POWER & the frontend is powered up and is ready to be used\\
+FE\_HAS\_SIGNAL & the frontend detects a signal above the normal noise level\\
+FE\_SPECTRUM\_INV & spectrum inversion is enabled/was necessary for lock\\
+FE\_HAS\_LOCK & frontend successfully locked to a DVB signal \\
+TUNER\_HAS\_LOCK & the tuner has a frequency lock
+\end{tabular}
+
+
+\devsubsubsec{frontend parameters}
+\label{frontendparameters}
+
+The kind of parameters passed to the frontend device for tuning
+depend on the kind of hardware you are using.
+All kinds of parameters are combined as a union in the
+FrontendParameters structure:
+\begin{verbatim}
+typedef struct {
+ __u32 Frequency; /* (absolute) frequency in Hz for QAM/OFDM */
+ /* intermediate frequency in kHz for QPSK */
+ union {
+ QPSKParameters qpsk;
+ QAMParameters qam;
+ OFDMParameters ofdm;
+ } u;
+} FrontendParameters;
+\end{verbatim}
+
+For satellite QPSK frontends you have to use QPSKParameters defined by
+\begin{verbatim}
+typedef struct {
+ __u32 SymbolRate; /* symbol rate in Symbols per second */
+ CodeRate FEC_inner; /* forward error correction (see above) */
+} QPSKParameters;
+\end{verbatim}
+for cable QAM frontend you use the QAMParameters structure
+\begin{verbatim}
+typedef struct {
+ __u32 SymbolRate; /* symbol rate in Symbols per second */
+ CodeRate FEC_inner; /* forward error correction (see above) */
+ CodeRate FEC_outer; /* forward error correction (see above) */
+ Modulation QAM; /* modulation type (see above) */
+} QAMParameters;
+\end{verbatim}
+DVB-T frontends are supported by the OFDMParamters structure
+\begin{verbatim}
+typedef struct {
+ BandWidth bandWidth;
+ CodeRate HP_CodeRate; /* high priority stream code rate
*/
+ CodeRate LP_CodeRate; /* low priority stream code rate */
+ Modulation Constellation; /* modulation type (see above) */
+ TransmitMode TransmissionMode;
+ GuardInterval guardInterval;
+ Hierarchy HierarchyInformation;
+} OFDMParameters;
+\end{verbatim}
+
+In the case of QPSK frontends the Frequency field specifies the intermediate
+frequency, i.e. the offset which is effectively added to the local oscillator
+frequency (LOF) of the LNB.
+The intermediate frequency has to be specified in units of kHz.
+For QAM and OFDM frontends the Frequency specifies the absolute frequency
+and is given in Hz.
+
+\noindent
+The possible values for the FEC\_inner field are
+\begin{verbatim}
+enum {
+ FEC_AUTO,
+ FEC_1_2,
+ FEC_2_3,
+ FEC_3_4,
+ FEC_5_6,
+ FEC_7_8,
+ FEC_NONE
+};
+\end{verbatim}
+which correspond to error correction rates of $1\over 2$, $2\over 3$, etc.,
+no error correction or auto detection.
+
+\noindent
+For cable and terrestrial frontends (QAM and OFDM) one also has to
+specify the quadrature modulation mode which can be one of the following:
+\begin{verbatim}
+typedef enum
+{ QPSK,
+ QAM_16,
+ QAM_32,
+ QAM_64,
+ QAM_128,
+ QAM_256
+} QAM_TYPE;
+\end{verbatim}
+
+Finally, there are several more parameters for OFDM:
+\begin{verbatim}
+typedef enum {
+ TRANSMISSION_MODE_2K,
+ TRANSMISSION_MODE_8K
+} TransmitMode;
+\end{verbatim}
+
+\begin{verbatim}
+typedef enum {
+ BANDWIDTH_8_MHZ,
+ BANDWIDTH_7_MHZ,
+ BANDWIDTH_6_MHZ
+} BandWidth;
+\end{verbatim}
+
+\begin{verbatim}
+typedef enum {
+ GUARD_INTERVAL_1_32,
+ GUARD_INTERVAL_1_16,
+ GUARD_INTERVAL_1_8,
+ GUARD_INTERVAL_1_4
+} GuardInterval;
+\end{verbatim}
+
+\begin{verbatim}
+typedef enum {
+ HIERARCHY_NONE,
+ HIERARCHY_1,
+ HIERARCHY_2,
+ HIERARCHY_4
+} Hierarchy;
+\end{verbatim}
+
+
+\devsubsubsec{frontend events}
+\label{frontendevents}
+
+\begin{verbatim}
+enum {
+ FE_UNEXPECTED_EV,
+ FE_COMPLETION_EV,
+ FE_FAILURE_EV
+};
+\end{verbatim}
+
+\begin{verbatim}
+typedef struct {
+ EventType type; /* type of event, FE_UNEXPECTED_EV, ... */
+ long timestamp; /* time in seconds since 1970-01-01 */
+
+ union {
+ struct {
+ FrontendStatus previousStatus; /* status before event
*/
+ FrontendStatus currentStatus; /* status during event
*/
+ } unexpectedEvent;
+ FrontendParameters completionEvent; /* parameters for which
the
+ tuning succeeded */
+ FrontendStatus failureEvent; /* status at failure
(e.g. no lock) */
+ } u;
+} FrontendEvent;
+\end{verbatim}
+
+\begin{verbatim}
+struct qpskRegister {
+ uint8_t chipId;
+ uint8_t address;
+ uint8_t value;
+};
+\end{verbatim}
+
+\begin{verbatim}
+struct qamRegister {
+ uint8_t chipId;
+ uint8_t address;
+ uint8_t value;
+};
+\end{verbatim}
+
+\begin{verbatim}
+struct qpskFrontendInfo {
+ uint32_t minFrequency;
+ uint32_t maxFrequency;
+ uint32_t maxSymbolRate;
+ uint32_t minSymbolRate;
+ uint32_t hwType;
+ uint32_t hwVersion;
+};
+\end{verbatim}
+
+\begin{verbatim}
+struct qamFrontendInfo {
+ uint32_t minFrequency;
+ uint32_t maxFrequency;
+ uint32_t maxSymbolRate;
+ uint32_t minSymbolRate;
+ uint32_t hwType;
+ uint32_t hwVersion;
+};
+\end{verbatim}
+
+\begin{verbatim}
+typedef enum {
+ FE_POWER_ON,
+ FE_POWER_STANDBY,
+ FE_POWER_SUSPEND,
+ FE_POWER_OFF
+} powerState_t;
+\end{verbatim}
+
+
+\clearpage
+
+
+\devsubsec{Frontend Function Calls}
+
+\function{open()}{
+ int open(const char *deviceName, int flags);}{
+ This system call opens a named frontend device (e.g. /dev/ost/qpskfe
+ for a satellite frontend or /dev/ost/qamfe for a cable frontend)
+ for subsequent use.
+
+ The device can be opened in read-only mode, which only allows
+ monitoring of device status and statistics, or read/write mode, which allows
+ any kind of use (e.g. performing tuning operations.)
+
+ In a system with multiple front-ends, it is usually the case that multiple
+ devices cannot be open in read/write mode simultaneously. As long as a
+ front-end device is opened in read/write mode, other open() calls in
+ read/write mode will either fail or block, depending on whether
+ non-blocking or blocking mode was specified.
+ A front-end device opened in blocking mode can later be put into non-blocking
+ mode (and vice versa) using the F\_SETFL command of the fcntl system call.
+ This is a standard system call, documented in the Linux manual page for
fcntl.
+ When an open() call has succeeded, the device will be ready for use in the
+ specified mode. This implies that the corresponding hardware is powered up,
+ and that other front-ends may have been powered down to make that possible.
+
+ }{
+ const char *deviceName & Name of specific video device.\\
+ int flags & A bit-wise OR of the following flags:\\
+ & \hspace{1em} O\_RDONLY read-only access\\
+ & \hspace{1em} O\_RDWR read/write access\\
+ & \hspace{1em} O\_NONBLOCK open in non-blocking mode \\
+ & \hspace{1em} (blocking mode is the default)\\
+ }{
+ ENODEV & Device driver not loaded/available.\\
+ EINTERNAL & Internal error.\\
+ EBUSY & Device or resource busy.\\
+ EINVAL & Invalid argument.\\
+}
+
+\function{close()}{
+ int close(int fd);}{
+ This system call closes a previously opened front-end device.
+ After closing a front-end device, its corresponding hardware might be
+ powered down automatically, but only when this is needed to open
+ another front-end device.
+ To affect an unconditional power down, it should be done explicitly using
+ the OST\_SET\_POWER\_STATE ioctl.
+ This system call closes a previously opened audio device.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ }{
+ EBADF & fd is not a valid open file descriptor.\\
+}
+
+\ifunction{OST\_SELFTEST}{
+ int ioctl(int fd, int request = OST\_SELFTEST);}{
+ This ioctl call initiates an automatic self-test of the front-end hardware.
+ This call requires read/write access to the device.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals OST\_SELFTEST for this command.\\
+ }{
+ -1& Self test failure.\\
+}
+
+\ifunction{OST\_SET\_POWER\_STATE}{
+ int ioctl(int fd, int request = OST\_SET\_POWER\_STATE, uint32\_t state);}{
+ This ioctl call, implemented in many OST device drivers, enables direct
+ control over the power state of the hardware device, which may be on, off,
+ standby, or suspend. The latter two are low-power modes, which disable all
+ functionality of the device until turned on again. In contrast to the off
+ state, however, the standby and suspend states resume operation in the same
+ state as when the device was active. The only difference between the standby
+ and suspend states is a different tradeoff between resume time and power
+ consumption. Power consumption may be lower in the suspend state at the
+ cost of a longer resume time.\\
+ A device that implements this call does not necessarily support two low-power
+ modes. If it only supports one low-power state, or none at all, the
+ OST\_SET\_POWER\_STATE operation for the missing states will
+ still succeed, but
+ it will be mapped to an existing state as per this table: \\
+ \begin{center}
+ \begin{tabular}[h]{cll}
+ number of low-power & requested state & resulting state\\
+ states supported &&\\
+ \\
+ 1 & standby & suspend \\
+ 1 & suspend & suspend \\
+ 0 & standby & on \\
+ 0 & suspend & on
+ \end{tabular}
+ \end{center}\\
+ For other cases where a required state is missing, an error code will be
+ returned. This can happen if a device does not support the power-off state,
+ but nevertheless implements this ioctl operation for control of low-power
+ states.
+ When opening a device in read/write mode, the driver ensures that the
+ corresponding hardware device is turned on initially. If the device is
+ later turned off or put in suspend mode, it has to be explicitly turned on
+ again.\\
+ This call requires read/write access to the device. (Note that the power
+ management driver can affect the power state of devices without using this
+ ioctl operation, so having exclusive read/write access to a device does not
+ imply total control over the power state.)
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals OST\_SET\_POWER\_STATE for this command.\\
+ uint32\_t state & Requested power state. One of: \\
+ &
+ \begin{tabular}[h]{ll}
+ OST\_POWER\_ON& turn power on\\
+ OST\_POWER\_STANDBY& set device in standby mode\\
+ OST\_POWER\_SUSPEND& set device in suspend mode\\
+ OST\_POWER\_OFF& turn power off\\
+ \end{tabular}
+ }{
+ EBADF& fd is not a valid open file descriptor.\\
+ EINVAL& Illegal state, or not available on this device.\\
+ EPERM & Permission denied (needs read/write access).\\
+ ENOSYS& Function not available for this device.
+}
+
+\ifunction{FE\_GET\_POWER\_STATE}{
+ int ioctl(int fd, int request = OST\_GET\_POWER\_STATE, uint32\_t *state);}{
+ This ioctl call, implemented in many OST device drivers, obtains the power
+ state of the hardware device, which may be on, off, standby, or suspend.
+ A device that implements this call does not necessarily support all four
states.
+ If there is only one low-power state, the suspend state will be returned for
+ that state. If there is no low-power state, the on state will be reported
+ standby and suspend states will be equivalent to the on state.
+ For this command, read-only access to the device is sufficient.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals OST\_GET\_POWER\_STATE for this command.\\
+ uint32\_t *state & Requested power state. One of: \\
+ &
+ \begin{tabular}[h]{ll}
+ OST\_POWER\_ON& power is on\\
+ OST\_POWER\_STANDBY& device in standby mode\\
+ OST\_POWER\_SUSPEND& device in suspend mode\\
+ OST\_POWER\_OFF& power is off\\
+ \end{tabular}
+ }{
+ EBADF& fd is not a valid open file descriptor.\\
+ EINVAL& Illegal state, or not available on this device.\\
+ EFAULT& state points to invalid address.\\
+ ENOSYS& Function not available for this device.
+}
+
+\ifunction{FE\_READ\_STATUS}{
+ int ioctl(int fd, int request = FE\_READ\_STATUS, feStatus *status);}{
+ This ioctl call returns status information about the front-end.
+ This call only requires read-only access to the device.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals FE\_READ\_STATUS for this command.\\
+ struct feStatus *status&Points to the location where the front-end
+ status word is to be stored.
+ }{
+ EBADF& fd is not a valid open file descriptor.\\
+ EFAULT& status points to invalid address.\\
+}
+
+\ifunction{FE\_READ\_BER}{
+ int ioctl(int fd, int request = FE\_READ\_BER, uint32\_t *ber);}{
+ This ioctl call returns the bit error rate for the signal currently
+ received/demodulated by the front-end. For this command, read-only access
+ to the device is sufficient.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals FE\_READ\_BER for this command.\\
+ uint32\_t *ber & The bit error rate, as a multiple of $10^{-9}$,
+ is stored into *ber.\\
+ & Example: a value of 2500 corresponds to a bit error
+ rate of $2.5\cdot 10^{-6}$, or 1 error in 400000 bits.
+ }{
+ EBADF& fd is not a valid open file descriptor.\\
+ EFAULT& ber points to invalid address.\\
+ ENOSIGNAL& There is no signal, thus no meaningful bit error
+ rate. Also returned if the front-end is not turned on.\\
+ ENOSYS& Function not available for this device.
+}
+
+\ifunction{FE\_READ\_SNR}{
+ int ioctl(int fd, int request = FE\_READ\_SNR, int32\_t *snr);}{
+ This ioctl call returns the signal-to-noise ratio for the signal currently
+ received by the front-end. For this command, read-only access to the device
+ is sufficient.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals FE\_READ\_SNR for this command.\\
+ int32\_t *snr& The signal-to-noise ratio, as a multiple of
+ $10^{-6}$ dB, is stored into *snr.\\
+ & Example: a value of 12,300,000 corresponds
+ to a signal-to-noise ratio of 12.3 dB.
+}{
+ EBADF& fd is not a valid open file descriptor.\\
+ EFAULT& snr points to invalid address.\\
+ ENOSIGNAL& There is no signal, thus no meaningful signal
+ strength value. Also returned if front-end is not turned on.\\
+ ENOSYS& Function not available for this device.
+}
+
+\ifunction{FE\_READ\_SIGNAL\_STRENGTH}{
+ int ioctl( int fd, int request = FE\_READ\_SIGNAL\_STRENGTH, int32\_t
*strength);
+}{
+This ioctl call returns the signal strength value for the signal currently
+received by the front-end. For this command, read-only access to the device
+is sufficient.
+}{
+int fd & File descriptor returned by a previous call to open().\\
+int request & Equals FE\_READ\_SIGNAL\_STRENGTH for this command.\\
+int32\_t *strength & The signal strength value, as a multiple of
+ $10^{-6 }$ dBm,
+ is stored into *strength. \\
+ &Example: a value of -12,500,000 corresponds to a signal
+ strength value of -12.5 dBm.
+}{
+ EBADF& fd is not a valid open file descriptor.\\
+ EFAULT& status points to invalid address.\\
+ ENOSIGNAL& There is no signal, thus no meaningful signal
+ strength value. Also returned if front-end is not turned on.\\
+ ENOSYS& Function not available for this device.
+}
+
+\ifunction{FE\_READ\_UNCORRECTED\_BLOCKS}{
+ int ioctl( int fd, int request = FE\_READ\_UNCORRECTED\_BLOCKS, uint32\_t
*ublocks); }{
+ This ioctl call returns the number of uncorrected blocks detected by
+ the device driver during its lifetime.
+ For meaningful measurements, the increment in
+ block count during a specific time interval should be calculated.
+ For this command, read-only access to the device is sufficient.\\
+ Note that the counter will wrap to zero after its maximum count has
+ been reached.
+}{
+int fd & File descriptor returned by a previous call to open().\\
+int request & Equals FE\_READ\_UNCORRECTED\_BLOCKS for this command.\\
+uint32\_t *ublocks & The total number of uncorrected blocks seen
+by the driver so far.
+}{
+ EBADF& fd is not a valid open file descriptor.\\
+ EFAULT& ublocks points to invalid address.\\
+ ENOSYS& Function not available for this device.
+}
+
+
+\ifunction{FE\_GET\_NEXT\_FREQUENCY}{
+ int ioctl( int fd, int request = FE\_GET\_NEXT\_FREQUENCY, uint32\_t
*freq);}{
+ When scanning a frequency range, it is desirable to use a scanning step size
+ that is as large as possible, yet small enough to be able to lock to any
signal
+ within the range.
+ This ioctl operation does just that - it increments a given frequency by a
+ step size suitable for efficient scanning.
+ The step size used by this function may be a quite complex function of the
given
+ frequency, hardware capabilities, and parameter settings of the device.
Thus, a
+ returned result is only valid for the current state of the device.
+ For this command, read-only access to the device is sufficient.\\
+ Note that scanning may still be excruciatingly slow on some hardware, for
+ other reasons than a non-optimal scanning step size.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals FE\_GET\_NEXT\_FREQUENCY for this command.\\
+ uint32\_t *freq& Input: a given frequency \\
+ & Output: the frequency corresponding to
+ the next higher frequency setting.\\
+ }{
+ EBADF& fd is not a valid open file descriptor.\\
+ EFAULT& freq points to invalid address.\\
+ EINVAL& Maximum supported frequency reached.\\
+ ENOSYS& Function not available for this device.
+}
+
+\ifunction{FE\_GET\_NEXT\_SYMBOL\_RATE}{
+ int ioctl( int fd, int request = FE\_GET\_NEXT\_SYMBOL\_RATE, uint32\_t
*symbolRate);
+ }{
+ When scanning a range of symbol rates (e.g. for "blind acquisition") it is
+ desirable to use a scanning step size that is as large as possible, yet
+ small enough to detect any valid signal within the range. This ioctl
+ operation does just that - it increments a given symbol rate by a step size
+ suitable for efficient scanning.
+ The step size used by this function may be a quite complex function of the
given
+ symbol rate, hardware capabilities, and parameter settings of the device.
+ Thus, a returned result is only valid for the current state of the device.
+ For this command, read-only access to the device is sufficient.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals FE\_GET\_NEXT\_SYMBOL\_RATE for this command.\\
+ uint32\_t *symbolRate& Input: a given symbol rate \\
+ & Output: the symbol rate corresponding to
+ the next higher symbol rate.\\
+ }{
+ EBADF& fd is not a valid open file descriptor.\\
+ EFAULT& symbolRate points to invalid address.\\
+ EINVAL& Maximum supported symbol rate reached.\\
+ ENOSYS& Function not available for this device.
+}
+
+\ifunction{FE\_SET\_FRONTEND}{
+ int ioctl(int fd, int request = FE\_SET\_FRONTEND, struct FrontendParameters
*p);}{
+ This ioctl call starts a tuning operation using specified parameters.
+ The result of this call will be successful if the parameters were
valid and
+ the tuning could be initiated.
+ The result of the tuning operation in itself, however, will arrive
+ asynchronously as an event (see documentation for FE\_GET\_EVENT
+ and FrontendEvent.)
+ If a new FE\_SET\_FRONTEND operation is initiated before the previous
+ one was completed,
+ the previous operation will be aborted in favor of the new one.
+ This command requires read/write access to the device.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals FE\_SET\_FRONTEND for this command.\\
+ struct FrontendParameters *p& Points to parameters for tuning operation.\\
+ }{
+ EBADF& fd is not a valid open file descriptor.\\
+ EFAULT& p points to invalid address.\\
+ EINVAL& Maximum supported symbol rate reached.\\
+}
+
+\ifunction{FE\_GET\_EVENT}{
+ int ioctl(int fd, int request = QPSK\_GET\_EVENT, struct qpskEvent *ev);}{
+ This ioctl call returns an event of type qpskEvent if available. If an event
+ is not available, the behavior depends on whether the device is in blocking
+ or non-blocking mode. In the latter case, the call fails immediately with
+ errno set to EWOULDBLOCK. In the former case, the call blocks until an event
+ becomes available.\\
+ The standard Linux poll() and/or select() system calls can be used with the
+ device file descriptor to watch for new events. For select(), the file
+ descriptor should be included in the exceptfds argument, and for poll(),
+ POLLPRI should be specified as the wake-up condition.
+ Since the event queue allocated is rather small (room for 8 events), the
queue
+ must be serviced regularly to avoid overflow. If an overflow happens, the
+ oldest event is discarded from the queue, and an error (EBUFFEROVERFLOW)
occurs
+ the next time the queue is read. After reporting the error condition in this
+ fashion, subsequent QPSK\_GET\_EVENT calls will return events from the queue
as
+ usual.\\
+ For the sake of implementation simplicity, this command requires read/write
+ access to the device.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals QPSK\_GET\_EVENT for this command.\\
+ struct qpskEvent *ev&Points to the location where the event, if any, is to
be stored.
+ }{
+ EBADF& fd is not a valid open file descriptor.\\
+ EFAULT& ev points to invalid address.\\
+ EWOULDBLOCK & There is no event pending, and the device is in
+ non-blocking mode.\\
+ EBUFFEROVERFLOW &\\
+& Overflow in event queue - one or more events were lost.\\
+}
+
+\ifunction{FE\_GET\_INFO}{
+ int ioctl(int fd, int request = FE\_GET\_INFO, struct FrontendInfo *info);}{
+ This ioctl call returns information about the front-end.
+ This call only requires read-only access to the device.
+ }{
+ int fd & File descriptor returned by a previous call to open().\\
+ int request & Equals FE\_GET\_INFO for this command.\\
+ struct qpskFrontendInfo *info & Points to the location where the front-end
+ information is to be stored.
+ }{
+ EBADF& fd is not a valid open file descriptor.\\
+ EFAULT& info points to invalid address.\\
+}
+
+%%% Local Variables:
+%%% mode: latex
+%%% TeX-master: "dvbapi"
+%%% End:
---
Patch is available at:
http://linuxtv.org/hg/v4l-dvb/rev/da1df54d68c53516c7546367d4313659f0b3213e
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