Ricardo Ribalda a84391b773 media: uvcvideo: Import standard controls from uvcdynctrl
The uvcdynctrl tool from libwebcam:
https://sourceforge.net/projects/libwebcam/
maps proprietary controls into v4l2 controls using the UVCIOC_CTRL_MAP
ioctl.

The tool has not been updated for 10+ years now, and there is no reason
for the UVC driver to not do the mapping by itself.

This patch adds the mappings from the uvcdynctrl into the driver. Hopefully
this effort can help in deprecating the UVCIOC_CTRL_MAP ioctl.

Some background about UVCIOC_CTRL_MAP (thanks Laurent for the context):

```
this was envisioned as the base of a vibrant ecosystem where a large
number of vendors would submit XML files that describe their XU control
mappings, at a pace faster than could be supported by adding XU mappings
to the driver. This vision failed to materialize and the tool has not
been updated for 10+ years now. There is no reason to believe the
situation will change.
```

During the porting, the following mappings where NOT imported because
they were not using standard v4l2 IDs. It is recommended that userspace
moves to UVCIOC_CTRL_QUERY for non standard controls.

        {
                .id             = V4L2_CID_FLASH_MODE,
                .entity         = UVC_GUID_SIS_LED_HW_CONTROL,
                .selector       = 4,
                .size           = 4,
                .offset         = 0,
                .v4l2_type      = V4L2_CTRL_TYPE_MENU,
                .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
                .menu_mask      = 0x3,
                .menu_mapping   = { 0x20, 0x22 },
                .menu_names     = { "Off", "On" },

        },
        {
                .id             = V4L2_CID_FLASH_FREQUENCY,
                .entity         = UVC_GUID_SIS_LED_HW_CONTROL,
                .selector       = 4,
                .size           = 8,
                .offset         = 16,
                .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
                .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
        },
       {
               .id             = V4L2_CID_LED1_MODE,
               .entity         = UVC_GUID_LOGITECH_USER_HW_CONTROL_V1,
               .selector       = 1,
               .size           = 8,
               .offset         = 0,
               .v4l2_type      = V4L2_CTRL_TYPE_MENU,
               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
               .menu_mask      = 0xF,
               .menu_mapping   = { 0, 1, 2, 3 },
               .menu_names     = { "Off", "On", "Blinking", "Auto" },

       },
       {
               .id             = V4L2_CID_LED1_FREQUENCY,
               .entity         = UVC_GUID_LOGITECH_USER_HW_CONTROL_V1,
               .selector       = 1,
               .size           = 8,
               .offset         = 16,
               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
       },
       {
               .id             = V4L2_CID_DISABLE_PROCESSING,
               .entity         = UVC_GUID_LOGITECH_VIDEO_PIPE_V1,
               .selector       = 5,
               .size           = 8,
               .offset         = 0,
               .v4l2_type      = V4L2_CTRL_TYPE_BOOLEAN,
               .data_type      = UVC_CTRL_DATA_TYPE_BOOLEAN,
       },
       {
               .id             = V4L2_CID_RAW_BITS_PER_PIXEL,
               .entity         = UVC_GUID_LOGITECH_VIDEO_PIPE_V1,
               .selector       = 8,
               .size           = 8,
               .offset         = 0,
               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
       },
       {
               .id             = V4L2_CID_LED1_MODE,
               .entity         = UVC_GUID_LOGITECH_PERIPHERAL,
               .selector       = 0x09,
               .size           = 2,
               .offset         = 8,
               .v4l2_type      = V4L2_CTRL_TYPE_MENU,
               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
               .menu_mask      = 0xF,
               .menu_mapping   = { 0, 1, 2, 3 },
               .menu_names     = { "Off", "On", "Blink", "Auto" },

       },
       {
               .id             = V4L2_CID_LED1_FREQUENCY,
               .entity         = UVC_GUID_LOGITECH_PERIPHERAL,
               .selector       = 0x09,
               .size           = 8,
               .offset         = 24,
               .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
               .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
       },

This script has been used to generate the mappings. They were then
reformatted manually to follow the driver style.

import sys
import uuid
import re
import xml.etree.ElementTree as ET

def get_namespace(root):
    return re.match(r"\{.*\}", root.tag).group(0)

def get_single_guid(ns, constant):
    id = constant.find(ns + "id").text
    value = constant.find(ns + "value").text
    return (id, value)

def get_constants(ns, root):
    out = dict()
    for constant in root.iter(ns + "constant"):
        attr = constant.attrib
        if attr["type"] == "integer":
            id, value = get_single_guid(ns, constant)
            if id in out:
                print(f"dupe constant {id}")
            out[id] = value

    return out

def get_guids(ns, root):
    out = dict()
    for constant in root.iter(ns + "constant"):
        attr = constant.attrib
        if attr["type"] == "guid":
            id, value = get_single_guid(ns, constant)
            if id in out:
                print(f"dupe guid {id}")
            out[id] = value

    return out

def get_single_control(ns, control):
    out = {}
    for id in "entity", "selector", "index", "size", "description":
        v = control.find(ns + id)
        if v is None and id == "description":
            continue
        out[id] = v.text

    reqs = set()
    for r in control.find(ns + "requests"):
        reqs.add(r.text)
    out["requests"] = reqs

    return (control.attrib["id"], out)

def get_controls(ns, root):
    out = dict()
    for control in root.iter(ns + "control"):
        id, value = get_single_control(ns, control)
        if id in out:
            print(f"Dupe control id {id}")
        out[id] = value

    return out

def get_single_mapping(ns, mapping):
    out = {}
    out["name"] = mapping.find(ns + "name").text
    uvc = mapping.find(ns + "uvc")
    for id in "size", "offset", "uvc_type":
        out[id] = uvc.find(ns + id).text
    out["control_ref"] = uvc.find(ns + "control_ref").attrib["idref"]

    v4l2 = mapping.find(ns + "v4l2")
    for id in "id", "v4l2_type":
        out[id] = v4l2.find(ns + id).text

    menu = {}
    for entry in v4l2.iter(ns + "menu_entry"):
        menu[entry.attrib["name"]] = entry.attrib["value"]
    if menu:
        out["menu"] = menu

    return out

def get_mapping(ns, root):
    out = []
    for control in root.iter(ns + "mapping"):
        mapping = get_single_mapping(ns, control)
        out += [mapping]

    return out

def print_guids(guids):
    for g in guids:
        print(f"#define {g} \\")
        u_bytes = uuid.UUID(guids[g]).bytes_le
        u_bytes = [f"0x{b:02x}" for b in u_bytes]
        print("\t{ " + ", ".join(u_bytes) + " }")

def print_flags(flags):
    get_range = {"GET_MIN", "GET_DEF", "GET_MAX", "GET_CUR", "GET_RES"}
    if get_range.issubset(flags):
        flags -= get_range
        flags.add("GET_RANGE")

    flags = list(flags)
    flags.sort()
    out = ""
    for f in flags[:-1]:
        out += f"UVC_CTRL_FLAG_{f}\n\t\t\t\t| "

    out += f"UVC_CTRL_FLAG_{flags[-1]}"

    return out

def print_description(desc):
    print("/*")
    for line in desc.strip().splitlines():
        print(f" * {line.strip()}")
    print("*/")

def print_controls(controls, cons):
    for id in controls:
        c = controls[id]
        if "description" in c:
            print_description(c["description"])
        print(
            f"""\t{{
\t\t.entity\t\t= {c["entity"]},
\t\t.selector\t= {cons[c["selector"]]},
\t\t.index\t\t= {c["index"]},
\t\t.size\t\t= {c["size"]},
\t\t.flags\t\t= {print_flags(c["requests"])},
\t}},"""
        )

def menu_mapping_txt(menu):
    out = f"\n\t\t.menu_mask\t= 0x{((1<<len(menu))-1):X},\n"
    out += f"\t\t.menu_mapping\t= {{ {", ".join(menu.values())} }},\n"
    out += f"\t\t.menu_names\t= {{ \"{"\", \"".join(menu.keys())}\" }},\n"
    return out

def print_mappings(mappings, controls, cons):
    for m in mappings:
        c = controls[m["control_ref"]]

        if "menu" in m:
            menu_mapping = menu_mapping_txt(m["menu"])
        else:
            menu_mapping = ""
        print(
            f"""\t{{
\t\t.id\t\t= {m["id"]},
\t\t.entity\t\t= {c["entity"]},
\t\t.selector\t= {cons[c["selector"]]},
\t\t.size\t\t= {m["size"]},
\t\t.offset\t\t= {m["offset"]},
\t\t.v4l2_type\t= {m["v4l2_type"]},
\t\t.data_type\t= {m["uvc_type"]},{menu_mapping}
\t}},"""
        )

def print_code(guids, cons, controls, mappings):
    used_controls = set()
    for m in mappings:
        used_controls.add(m["control_ref"])

    used_guids = set()
    for c in used_controls:
        used_guids.add(controls[c]["entity"])

    print("\n######GUIDs#######\n")
    print_guids({id: guids[id] for id in guids if id in used_guids})
    print("\n######CONTROLS#######\n")
    print_controls({id: controls[id] for id in controls if id in used_controls}, cons)
    print("\n######MAPPINGS#######\n")
    print_mappings(mappings, controls, cons)
    # print(guids)
    # print(used_controls)

root = ET.fromstring(sys.stdin.read())
ns = get_namespace(root)
cons = get_constants(ns, root)
guids = get_guids(ns, root)
controls = get_controls(ns, root)
mappings = get_mapping(ns, root)
print_code(guids, cons, controls, mappings)

Cc: Manav Gautama <bandwidthcrunch@gmail.com>
Cc: Martin Rubli <martin_rubli@logitech.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
2026-05-12 07:30:53 +02:00
2026-01-26 19:07:09 -08:00
2022-09-28 09:02:20 +02:00
2025-02-19 14:53:27 -07:00
2026-04-26 14:19:00 -07:00

Linux kernel
============

The Linux kernel is the core of any Linux operating system. It manages hardware,
system resources, and provides the fundamental services for all other software.

Quick Start
-----------

* Report a bug: See Documentation/admin-guide/reporting-issues.rst
* Get the latest kernel: https://kernel.org
* Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst
* Join the community: https://lore.kernel.org/

Essential Documentation
-----------------------

All users should be familiar with:

* Building requirements: Documentation/process/changes.rst
* Code of Conduct: Documentation/process/code-of-conduct.rst
* License: See COPYING

Documentation can be built with make htmldocs or viewed online at:
https://www.kernel.org/doc/html/latest/


Who Are You?
============

Find your role below:

* New Kernel Developer - Getting started with kernel development
* Academic Researcher - Studying kernel internals and architecture
* Security Expert - Hardening and vulnerability analysis
* Backport/Maintenance Engineer - Maintaining stable kernels
* System Administrator - Configuring and troubleshooting
* Maintainer - Leading subsystems and reviewing patches
* Hardware Vendor - Writing drivers for new hardware
* Distribution Maintainer - Packaging kernels for distros
* AI Coding Assistant - LLMs and AI-powered development tools


For Specific Users
==================

New Kernel Developer
--------------------

Welcome! Start your kernel development journey here:

* Getting Started: Documentation/process/development-process.rst
* Your First Patch: Documentation/process/submitting-patches.rst
* Coding Style: Documentation/process/coding-style.rst
* Build System: Documentation/kbuild/index.rst
* Development Tools: Documentation/dev-tools/index.rst
* Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst
* Core APIs: Documentation/core-api/index.rst

Academic Researcher
-------------------

Explore the kernel's architecture and internals:

* Researcher Guidelines: Documentation/process/researcher-guidelines.rst
* Memory Management: Documentation/mm/index.rst
* Scheduler: Documentation/scheduler/index.rst
* Networking Stack: Documentation/networking/index.rst
* Filesystems: Documentation/filesystems/index.rst
* RCU (Read-Copy Update): Documentation/RCU/index.rst
* Locking Primitives: Documentation/locking/index.rst
* Power Management: Documentation/power/index.rst

Security Expert
---------------

Security documentation and hardening guides:

* Security Documentation: Documentation/security/index.rst
* LSM Development: Documentation/security/lsm-development.rst
* Self Protection: Documentation/security/self-protection.rst
* Reporting Vulnerabilities: Documentation/process/security-bugs.rst
* CVE Procedures: Documentation/process/cve.rst
* Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst
* Security Features: Documentation/userspace-api/seccomp_filter.rst

Backport/Maintenance Engineer
-----------------------------

Maintain and stabilize kernel versions:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* Backporting Guide: Documentation/process/backporting.rst
* Applying Patches: Documentation/process/applying-patches.rst
* Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git for Maintainers: Documentation/maintainer/configure-git.rst

System Administrator
--------------------

Configure, tune, and troubleshoot Linux systems:

* Admin Guide: Documentation/admin-guide/index.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst
* Tracing/Debugging: Documentation/trace/index.rst
* Performance Security: Documentation/admin-guide/perf-security.rst
* Hardware Monitoring: Documentation/hwmon/index.rst

Maintainer
----------

Lead kernel subsystems and manage contributions:

* Maintainer Handbook: Documentation/maintainer/index.rst
* Pull Requests: Documentation/maintainer/pull-requests.rst
* Managing Patches: Documentation/maintainer/modifying-patches.rst
* Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst
* Development Process: Documentation/process/maintainer-handbooks.rst
* Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst
* Git Configuration: Documentation/maintainer/configure-git.rst

Hardware Vendor
---------------

Write drivers and support new hardware:

* Driver API Guide: Documentation/driver-api/index.rst
* Driver Model: Documentation/driver-api/driver-model/driver.rst
* Device Drivers: Documentation/driver-api/infrastructure.rst
* Bus Types: Documentation/driver-api/driver-model/bus.rst
* Device Tree Bindings: Documentation/devicetree/bindings/
* Power Management: Documentation/driver-api/pm/index.rst
* DMA API: Documentation/core-api/dma-api.rst

Distribution Maintainer
-----------------------

Package and distribute the kernel:

* Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst
* ABI Documentation: Documentation/ABI/README
* Kernel Configuration: Documentation/kbuild/kconfig.rst
* Module Signing: Documentation/admin-guide/module-signing.rst
* Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst
* Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst

AI Coding Assistant
-------------------

CRITICAL: If you are an LLM or AI-powered coding assistant, you MUST read and
follow the AI coding assistants documentation before contributing to the Linux
kernel:

* Documentation/process/coding-assistants.rst

This documentation contains essential requirements about licensing, attribution,
and the Developer Certificate of Origin that all AI tools must comply with.


Communication and Support
=========================

* Mailing Lists: https://lore.kernel.org/
* IRC: #kernelnewbies on irc.oftc.net
* Bugzilla: https://bugzilla.kernel.org/
* MAINTAINERS file: Lists subsystem maintainers and mailing lists
* Email Clients: Documentation/process/email-clients.rst
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