lirc.4: Update after upstreamed lirc.h, bugfixes.

The lirc.h header has landed in the kernel, and the kernel docs
has been updated all of which reflected in this patch.

Here is still an open issue with duplicated info in the kernel
docs and the manpage. Eventually, this should be addressed but
I frankly don't know how. In the meantime, acknowledge the fact
that the kernel docs is the ultimate source

man4/lirc.4

@@ -1,4 +1,4 @@
-.\" Copyright (c) 2015, Alec Leamas
+.\" Copyright (c) 2015-2016, Alec Leamas
 .\"
 .\" %%%LICENSE_START(GPLv2+_DOC_FULL)
 .\" This is free documentation; you can redistribute it and/or
@@ -20,7 +20,7 @@
 .\" License along with this manual; if not, see
 .\" <http://www.gnu.org/licenses/>.
 .\" %%%LICENSE_END
-.TH LIRC 4 "2016-03-17" "Linux" "Linux Programmer's Manual"
+.TH LIRC 4 "2016-05-20" "Linux" "Linux Programmer's Manual"
 .SH NAME
 lirc \- lirc devices
 .SH DESCRIPTION
@@ -111,7 +111,18 @@ If more data is provided than the hardware can send, the
 call fails with the error
 .BR EINVAL
 .\"
-.SH SUPPORTED IOCTL COMMANDS
+.SH IOCTL COMMANDS
+.P
+The complete list of ioctl commands is maintained in the kernel
+documentation, see SEE ALSO.
+The ioctl commands presented here is a subset  of the kernel
+docs.
+.P
+The LIRC device's ioctl definition is bound by the ioctl function
+definition of struct file_operations, leaving us with an unsigned
+int for the ioctl command and an unsigned long for the arg.
+For the purposes of ioctl portability across 32-bit and 64-bit,
+these values are capped to their 32-bit sizes.
 .P
 .nf
 #include <lirc/include/media/lirc.h>    /* But see BUGS */
@@ -140,6 +151,8 @@ Returns a bit mask of combined features bits; see FEATURES.
 Some drivers have dynamic features which are not updated until after an
 .I init()
 command.
+If a driver does not announce support of certain features, calling of
+the corresponding ioctls is undefined.
 .TP
 .BR LIRC_GET_REC_MODE
 Return the receive mode, which will be one of:
@@ -191,10 +204,16 @@ Currently serves no purpose since only
 .BR LIRC_MODE_PULSE
 is supported.
 .TP
+.BR LIRC_GET_SEND_CARRIER " (\fIvoid\fP)"
+Get the modulation frequency (Hz).
+.TP
 .BR LIRC_SET_SEND_CARRIER " (\fIint\fP)"
 Set the modulation frequency.
 The argument is the frequency (Hz).
 .TP
+.BR LIRC_GET_SEND_CARRIER " (\fIvoid\fP)"
+Get the modulation frequency used when decoding (Hz).
+.TP
 .BR SET_SEND_DUTY_CYCLE " (\fIint\fP)"
 Set the carrier duty cycle.
 .I val
@@ -202,6 +221,7 @@ is a number in the range [0,100] which
 describes the pulse width as a percentage of the total cycle.
 Currently, no special meaning is defined for 0 or 100, but the values
 are reserved for future use.
+
 .TP
 .BR LIRC_GET_MIN_TIMEOUT " (\fIvoid\fP)", " "\
 LIRC_GET_MAX_TIMEOUT " (\fIvoid\fP)"
@@ -444,9 +464,8 @@ sending.)
 .SH BUGS
 Using these devices requires the kernel source header file
 .IR lirc.h .
-This file is not (yet) publicly exported by kernel headers.
-.\" FIXME . https://bugzilla.kernel.org/show_bug.cgi?id=3D75751.
-For the time being, the file is bundled in the lirc package; see
+This file is not available before kernel release 4.6. Users of older
+kernels could use the file bundled in
 .UR http://www.lirc.org
 .UE .
 .\"