From e452134cee5593612e515265247d271c36d6ca33 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Thu, 8 Sep 2016 06:21:01 -0300 Subject: [PATCH] [media] libv4l-introduction.rst: improve crossr-references Use C cross-references to mention the V4L2 API calls on all places it occurs inside this file. While here, also mark constants as such. Signed-off-by: Mauro Carvalho Chehab --- .../media/uapi/v4l/libv4l-introduction.rst | 33 +++++++++++-------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/Documentation/media/uapi/v4l/libv4l-introduction.rst b/Documentation/media/uapi/v4l/libv4l-introduction.rst index 1c1278d17fa7..ccc3c4d2fc0f 100644 --- a/Documentation/media/uapi/v4l/libv4l-introduction.rst +++ b/Documentation/media/uapi/v4l/libv4l-introduction.rst @@ -113,43 +113,47 @@ Libv4l device control functions The common file operation methods are provided by libv4l. -Those functions operate just like glibc -open/close/dup/ioctl/read/mmap/munmap: +Those functions operate just like the gcc function ``dup()`` and +V4L2 functions +:c:func:`open() `, :c:func:`close() `, +:c:func:`ioctl() `, :c:func:`read() `, +:c:func:`mmap() ` and :c:func:`munmap() `: .. c:function:: int v4l2_open(const char *file, int oflag, ...) - operates like the standard :ref:`open() ` function. + operates like the :c:func:`open() ` function. .. c:function:: int v4l2_close(int fd) - operates like the standard :ref:`close() ` function. + operates like the :c:func:`close() ` function. .. c:function:: int v4l2_dup(int fd) - operates like the standard dup() function, duplicating a file handler. + operates like the libc ``dup()`` function, duplicating a file handler. .. c:function:: int v4l2_ioctl (int fd, unsigned long int request, ...) - operates like the standard :ref:`ioctl() ` function. + operates like the :c:func:`ioctl() ` function. .. c:function:: int v4l2_read (int fd, void* buffer, size_t n) - operates like the standard :ref:`read() ` function. + operates like the :c:func:`read() ` function. .. c:function:: void v4l2_mmap(void *start, size_t length, int prot, int flags, int fd, int64_t offset); - operates like the standard :ref:`mmap() ` function. + operates like the :c:func:`munmap() ` function. .. c:function:: int v4l2_munmap(void *_start, size_t length); - operates like the standard :ref:`munmap() ` function. + + operates like the :c:func:`munmap() ` function. Those functions provide additional control: .. c:function:: int v4l2_fd_open(int fd, int v4l2_flags) opens an already opened fd for further use through v4l2lib and possibly - modify libv4l2's default behavior through the v4l2_flags argument. - Currently, v4l2_flags can be ``V4L2_DISABLE_CONVERSION``, to disable + modify libv4l2's default behavior through the ``v4l2_flags`` argument. + Currently, ``v4l2_flags`` can be ``V4L2_DISABLE_CONVERSION``, to disable format conversion. .. c:function:: int v4l2_set_control(int fd, int cid, int value) @@ -168,9 +172,12 @@ Those functions provide additional control: v4l1compat.so wrapper library ============================= -This library intercepts calls to open/close/ioctl/mmap/mmunmap +This library intercepts calls to +:c:func:`open() `, :c:func:`close() `, +:c:func:`ioctl() `, :c:func:`mmap() ` and +:c:func:`munmap() ` operations and redirects them to the libv4l counterparts, by using -LD_PRELOAD=/usr/lib/v4l1compat.so. It also emulates V4L1 calls via V4L2 +``LD_PRELOAD=/usr/lib/v4l1compat.so``. It also emulates V4L1 calls via V4L2 API. It allows usage of binary legacy applications that still don't use -- 2.30.2