Files
video-setup/include/v4l2_ctrl.h
mikael-lovqvists-claude-agent a29c556851 Add common, media_ctrl and v4l2_ctrl modules with CLI drivers and docs
Modules (src/modules/):
- common/error: App_Error struct with structured detail union, error codes,
  app_error_print(); designed for future upgrade to preprocessor-generated
  location codes
- media_ctrl: media device enumeration, topology query (entities/pads/links),
  link enable/disable via Media Controller API (/dev/media*)
- v4l2_ctrl: control enumeration (with menu item fetching), get/set via
  V4L2 ext controls API, device discovery (/dev/video*)

All modules use -std=c11 -D_GNU_SOURCE, build artifacts go to build/ only.
Kernel-version-dependent constants guarded with #ifdef + #warning.

CLI drivers (dev/cli/):
- media_ctrl_cli: list, info, topology, set-link subcommands
- v4l2_ctrl_cli: list, controls, get, set subcommands

Docs (docs/cli/):
- media_ctrl_cli.md and v4l2_ctrl_cli.md with usage, examples, and
  context within the video routing system

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-03-25 21:40:37 +00:00

76 lines
1.9 KiB
C

#pragma once
#include <stdint.h>
#include "error.h"
/* Opaque handle — defined in v4l2_ctrl.c */
struct V4l2_Ctrl_Handle;
typedef enum V4l2_Ctrl_Type {
CTRL_TYPE_INTEGER = 1,
CTRL_TYPE_BOOLEAN = 2,
CTRL_TYPE_MENU = 3,
CTRL_TYPE_BUTTON = 4,
CTRL_TYPE_INTEGER64 = 5,
CTRL_TYPE_CTRL_CLASS = 6,
CTRL_TYPE_STRING = 7,
CTRL_TYPE_BITMASK = 8,
CTRL_TYPE_INTEGER_MENU = 9,
CTRL_TYPE_UNKNOWN = 0xff,
} V4l2_Ctrl_Type;
struct V4l2_Ctrl_Desc {
uint32_t id;
char name[32];
V4l2_Ctrl_Type type;
int32_t min;
int32_t max;
int32_t step;
int32_t default_value;
int32_t current_value;
uint32_t flags;
};
struct V4l2_Menu_Item {
uint32_t index;
char name[32]; /* for CTRL_TYPE_MENU */
int64_t value; /* for CTRL_TYPE_INTEGER_MENU */
};
/*
* Enumerate all /dev/video* device nodes present on the system.
*/
struct App_Error v4l2_ctrl_find_devices(
void (*callback)(const char *device_path, void *userdata),
void *userdata);
struct App_Error v4l2_ctrl_open(const char *device_path, struct V4l2_Ctrl_Handle **out);
void v4l2_ctrl_close(struct V4l2_Ctrl_Handle *handle);
/*
* Enumerate all controls on the device.
* For menu and integer-menu controls, menu_items is a non-NULL array of
* menu_count items. For all other types, menu_items is NULL and menu_count is 0.
*/
struct App_Error v4l2_ctrl_enumerate(
struct V4l2_Ctrl_Handle *handle,
void (*callback)(
const struct V4l2_Ctrl_Desc *desc,
uint32_t menu_count,
const struct V4l2_Menu_Item *menu_items,
void *userdata),
void *userdata);
struct App_Error v4l2_ctrl_get(
struct V4l2_Ctrl_Handle *handle,
uint32_t id,
int32_t *value_out);
struct App_Error v4l2_ctrl_set(
struct V4l2_Ctrl_Handle *handle,
uint32_t id,
int32_t value);
/* Human-readable name for a control type */
const char *v4l2_ctrl_type_name(V4l2_Ctrl_Type type);