// SPDX-License-Identifier: GPL-2.0-or-later /* * Video for Linux Two * * A generic video device interface for the LINUX operating system * using a set of device structures/vectors for low level operations. * * This file replaces the videodev.c file that comes with the * regular kernel distribution. * * Author: Bill Dirks <[email protected]> * based on code by Alan Cox, <[email protected]> */ /* * Video capture interface for Linux * * A generic video device interface for the LINUX operating system * using a set of device structures/vectors for low level operations. * * Author: Alan Cox, <[email protected]> * * Fixes: */ /* * Video4linux 1/2 integration by Justin Schoeman * <[email protected]> * 2.4 PROCFS support ported from 2.4 kernels by * Iñaki García Etxebarria <[email protected]> * Makefile fix by "W. Michael Petullo" <[email protected]> * 2.4 devfs support ported from 2.4 kernels by * Dan Merillat <[email protected]> * Added Gerd Knorrs v4l1 enhancements (Justin Schoeman) */ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/uaccess.h> #include <asm/io.h> #include <asm/div64.h> #include <media/v4l2-common.h> #include <media/v4l2-device.h> #include <media/v4l2-ctrls.h> #include <linux/videodev2.h> /* * * V 4 L 2 D R I V E R H E L P E R A P I * */ /* * Video Standard Operations (contributed by Michael Schimek) */ /* Helper functions for control handling */ /* Fill in a struct v4l2_queryctrl */ int v4l2_ctrl_query_fill(struct v4l2_queryctrl *qctrl, s32 _min, s32 _max, s32 _step, s32 _def) { … } EXPORT_SYMBOL(…); /* Clamp x to be between min and max, aligned to a multiple of 2^align. min * and max don't have to be aligned, but there must be at least one valid * value. E.g., min=17,max=31,align=4 is not allowed as there are no multiples * of 16 between 17 and 31. */ static unsigned int clamp_align(unsigned int x, unsigned int min, unsigned int max, unsigned int align) { … } static unsigned int clamp_roundup(unsigned int x, unsigned int min, unsigned int max, unsigned int alignment) { … } void v4l_bound_align_image(u32 *w, unsigned int wmin, unsigned int wmax, unsigned int walign, u32 *h, unsigned int hmin, unsigned int hmax, unsigned int halign, unsigned int salign) { … } EXPORT_SYMBOL_GPL(…); const void * __v4l2_find_nearest_size(const void *array, size_t array_size, size_t entry_size, size_t width_offset, size_t height_offset, s32 width, s32 height) { … } EXPORT_SYMBOL_GPL(…); int v4l2_g_parm_cap(struct video_device *vdev, struct v4l2_subdev *sd, struct v4l2_streamparm *a) { … } EXPORT_SYMBOL_GPL(…); int v4l2_s_parm_cap(struct video_device *vdev, struct v4l2_subdev *sd, struct v4l2_streamparm *a) { … } EXPORT_SYMBOL_GPL(…); const struct v4l2_format_info *v4l2_format_info(u32 format) { … } EXPORT_SYMBOL(…); static inline unsigned int v4l2_format_block_width(const struct v4l2_format_info *info, int plane) { … } static inline unsigned int v4l2_format_block_height(const struct v4l2_format_info *info, int plane) { … } void v4l2_apply_frmsize_constraints(u32 *width, u32 *height, const struct v4l2_frmsize_stepwise *frmsize) { … } EXPORT_SYMBOL_GPL(…); int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt, u32 pixelformat, u32 width, u32 height) { … } EXPORT_SYMBOL_GPL(…); int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat, u32 width, u32 height) { … } EXPORT_SYMBOL_GPL(…); s64 v4l2_get_link_freq(struct v4l2_ctrl_handler *handler, unsigned int mul, unsigned int div) { … } EXPORT_SYMBOL_GPL(…); /* * Simplify a fraction using a simple continued fraction decomposition. The * idea here is to convert fractions such as 333333/10000000 to 1/30 using * 32 bit arithmetic only. The algorithm is not perfect and relies upon two * arbitrary parameters to remove non-significative terms from the simple * continued fraction decomposition. Using 8 and 333 for n_terms and threshold * respectively seems to give nice results. */ void v4l2_simplify_fraction(u32 *numerator, u32 *denominator, unsigned int n_terms, unsigned int threshold) { … } EXPORT_SYMBOL_GPL(…); /* * Convert a fraction to a frame interval in 100ns multiples. The idea here is * to compute numerator / denominator * 10000000 using 32 bit fixed point * arithmetic only. */ u32 v4l2_fraction_to_interval(u32 numerator, u32 denominator) { … } EXPORT_SYMBOL_GPL(…); int v4l2_link_freq_to_bitmap(struct device *dev, const u64 *fw_link_freqs, unsigned int num_of_fw_link_freqs, const s64 *driver_link_freqs, unsigned int num_of_driver_link_freqs, unsigned long *bitmap) { … } EXPORT_SYMBOL_GPL(…);
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