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