mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-01 06:33:07 +00:00
media: v4l2-common.h: document helper functions
There are several helper functions that aren't documented. Document them. Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Mauro Carvalho Chehab
parent
0545629e50
commit
76a59fe770
2 changed files with 96 additions and 25 deletions
|
|
@ -320,20 +320,6 @@ static unsigned int clamp_align(unsigned int x, unsigned int min,
|
|||
return x;
|
||||
}
|
||||
|
||||
/* Bound an image to have a width between wmin and wmax, and height between
|
||||
* hmin and hmax, inclusive. Additionally, the width will be a multiple of
|
||||
* 2^walign, the height will be a multiple of 2^halign, and the overall size
|
||||
* (width*height) will be a multiple of 2^salign. The image may be shrunk
|
||||
* or enlarged to fit the alignment constraints.
|
||||
*
|
||||
* The width or height maximum must not be smaller than the corresponding
|
||||
* minimum. The alignments must not be so high there are no possible image
|
||||
* sizes within the allowed bounds. wmin and hmin must be at least 1
|
||||
* (don't use 0). If you don't care about a certain alignment, specify 0,
|
||||
* as 2^0 is 1 and one byte alignment is equivalent to no alignment. If
|
||||
* you only want to adjust downward, specify a maximum that's the same as
|
||||
* the initial value.
|
||||
*/
|
||||
void v4l_bound_align_image(u32 *w, unsigned int wmin, unsigned int wmax,
|
||||
unsigned int walign,
|
||||
u32 *h, unsigned int hmin, unsigned int hmax,
|
||||
|
|
|
|||
|
|
@ -28,7 +28,7 @@
|
|||
|
||||
#include <media/v4l2-dev.h>
|
||||
|
||||
/* Common printk constucts for v4l-i2c drivers. These macros create a unique
|
||||
/* Common printk constructs for v4l-i2c drivers. These macros create a unique
|
||||
prefix consisting of the driver name, the adapter number and the i2c
|
||||
address. */
|
||||
#define v4l_printk(level, name, adapter, addr, fmt, arg...) \
|
||||
|
|
@ -174,17 +174,43 @@ void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
|
|||
*/
|
||||
unsigned short v4l2_i2c_subdev_addr(struct v4l2_subdev *sd);
|
||||
|
||||
/**
|
||||
* enum v4l2_i2c_tuner_type - specifies the range of tuner address that
|
||||
* should be used when seeking for I2C devices.
|
||||
*
|
||||
* @ADDRS_RADIO: Radio tuner addresses.
|
||||
* Represent the following I2C addresses:
|
||||
* 0x10 (if compiled with tea5761 support)
|
||||
* and 0x60.
|
||||
* @ADDRS_DEMOD: Demod tuner addresses.
|
||||
* Represent the following I2C addresses:
|
||||
* 0x42, 0x43, 0x4a and 0x4b.
|
||||
* @ADDRS_TV: TV tuner addresses.
|
||||
* Represent the following I2C addresses:
|
||||
* 0x42, 0x43, 0x4a, 0x4b, 0x60, 0x61, 0x62,
|
||||
* 0x63 and 0x64.
|
||||
* @ADDRS_TV_WITH_DEMOD: TV tuner addresses if demod is present, this
|
||||
* excludes addresses used by the demodulator
|
||||
* from the list of candidates.
|
||||
* Represent the following I2C addresses:
|
||||
* 0x60, 0x61, 0x62, 0x63 and 0x64.
|
||||
*
|
||||
* NOTE: All I2C addresses above use the 7-bit notation.
|
||||
*/
|
||||
enum v4l2_i2c_tuner_type {
|
||||
ADDRS_RADIO, /* Radio tuner addresses */
|
||||
ADDRS_DEMOD, /* Demod tuner addresses */
|
||||
ADDRS_TV, /* TV tuner addresses */
|
||||
/* TV tuner addresses if demod is present, this excludes
|
||||
addresses used by the demodulator from the list of
|
||||
candidates. */
|
||||
ADDRS_RADIO,
|
||||
ADDRS_DEMOD,
|
||||
ADDRS_TV,
|
||||
ADDRS_TV_WITH_DEMOD,
|
||||
};
|
||||
/* Return a list of I2C tuner addresses to probe. Use only if the tuner
|
||||
addresses are unknown. */
|
||||
/**
|
||||
* v4l2_i2c_tuner_addrs - Return a list of I2C tuner addresses to probe.
|
||||
*
|
||||
* @type: type of the tuner to seek, as defined by
|
||||
* &enum v4l2_i2c_tuner_type.
|
||||
*
|
||||
* NOTE: Use only if the tuner addresses are unknown.
|
||||
*/
|
||||
const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type);
|
||||
|
||||
/* ------------------------------------------------------------------------- */
|
||||
|
|
@ -228,6 +254,9 @@ void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
|
|||
* FIXME: these remaining ioctls/structs should be removed as well, but they
|
||||
* are still used in tuner-simple.c (TUNER_SET_CONFIG) and cx18/ivtv (RESET).
|
||||
* To remove these ioctls some more cleanup is needed in those modules.
|
||||
*
|
||||
* It doesn't make much sense on documenting them, as what we really want is
|
||||
* to get rid of them.
|
||||
*/
|
||||
|
||||
/* s_config */
|
||||
|
|
@ -243,17 +272,73 @@ struct v4l2_priv_tun_config {
|
|||
|
||||
/* Miscellaneous helper functions */
|
||||
|
||||
void v4l_bound_align_image(unsigned int *w, unsigned int wmin,
|
||||
/**
|
||||
* v4l_bound_align_image - adjust video dimensions according to
|
||||
* a given constraints.
|
||||
*
|
||||
* @width: pointer to width that will be adjusted if needed.
|
||||
* @wmin: minimum width.
|
||||
* @wmax: maximum width.
|
||||
* @walign: least significant bit on width.
|
||||
* @height: pointer to height that will be adjusted if needed.
|
||||
* @hmin: minimum height.
|
||||
* @hmax: maximum height.
|
||||
* @halign: least significant bit on width.
|
||||
* @salign: least significant bit for the image size (e. g.
|
||||
* :math:`width * height`).
|
||||
*
|
||||
* Clip an image to have @width between @wmin and @wmax, and @height between
|
||||
* @hmin and @hmax, inclusive.
|
||||
*
|
||||
* Additionally, the @width will be a multiple of :math:`2^{walign}`,
|
||||
* the @height will be a multiple of :math:`2^{halign}`, and the overall
|
||||
* size :math:`width * height` will be a multiple of :math:`2^{salign}`.
|
||||
*
|
||||
* .. note::
|
||||
*
|
||||
* #. The clipping rectangle may be shrunk or enlarged to fit the alignment
|
||||
* constraints.
|
||||
* #. @wmax must not be smaller than @wmin.
|
||||
* #. @hmax must not be smaller than @hmin.
|
||||
* #. The alignments must not be so high there are no possible image
|
||||
* sizes within the allowed bounds.
|
||||
* #. @wmin and @hmin must be at least 1 (don't use 0).
|
||||
* #. For @walign, @halign and @salign, if you don't care about a certain
|
||||
* alignment, specify ``0``, as :math:`2^0 = 1` and one byte alignment
|
||||
* is equivalent to no alignment.
|
||||
* #. If you only want to adjust downward, specify a maximum that's the
|
||||
* same as the initial value.
|
||||
*/
|
||||
void v4l_bound_align_image(unsigned int *width, unsigned int wmin,
|
||||
unsigned int wmax, unsigned int walign,
|
||||
unsigned int *h, unsigned int hmin,
|
||||
unsigned int *height, unsigned int hmin,
|
||||
unsigned int hmax, unsigned int halign,
|
||||
unsigned int salign);
|
||||
|
||||
/**
|
||||
* v4l2_find_nearest_format - find the nearest format size among a discrete
|
||||
* set of resolutions.
|
||||
*
|
||||
* @sizes: array of &struct v4l2_frmsize_discrete image sizes.
|
||||
* @num_sizes: length of @sizes array.
|
||||
* @width: desired width.
|
||||
* @height: desired height.
|
||||
*
|
||||
* Finds the closest resolution to minimize the width and height differences
|
||||
* between what requested and the supported resolutions.
|
||||
*/
|
||||
const struct v4l2_frmsize_discrete *
|
||||
v4l2_find_nearest_format(const struct v4l2_frmsize_discrete *sizes,
|
||||
const size_t num_sizes,
|
||||
s32 width, s32 height);
|
||||
|
||||
/**
|
||||
* v4l2_get_timestamp - helper routine to get a timestamp to be used when
|
||||
* filling streaming metadata. Internally, it uses ktime_get_ts(),
|
||||
* which is the recommended way to get it.
|
||||
*
|
||||
* @tv: pointer to &struct timeval to be filled.
|
||||
*/
|
||||
void v4l2_get_timestamp(struct timeval *tv);
|
||||
|
||||
#endif /* V4L2_COMMON_H_ */
|
||||
|
|
|
|||
Loading…
Reference in a new issue