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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
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Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
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+.. SPDX-License-Identifier: GPL-2.0
+
+===================================
+GPIO Character Device Userspace API
+===================================
+
+This is latest version (v2) of the character device API, as defined in
+``include/uapi/linux/gpio.h.``
+
+First added in 5.10.
+
+.. note::
+ Do NOT abuse userspace APIs to control hardware that has proper kernel
+ drivers. There may already be a driver for your use case, and an existing
+ kernel driver is sure to provide a superior solution to bitbashing
+ from userspace.
+
+ Read Documentation/driver-api/gpio/drivers-on-gpio.rst to avoid reinventing
+ kernel wheels in userspace.
+
+ Similarly, for multi-function lines there may be other subsystems, such as
+ Documentation/spi/index.rst, Documentation/i2c/index.rst,
+ Documentation/driver-api/pwm.rst, Documentation/w1/index.rst etc, that
+ provide suitable drivers and APIs for your hardware.
+
+Basic examples using the character device API can be found in ``tools/gpio/*``.
+
+The API is based around two major objects, the :ref:`gpio-v2-chip` and the
+:ref:`gpio-v2-line-request`.
+
+.. _gpio-v2-chip:
+
+Chip
+====
+
+The Chip represents a single GPIO chip and is exposed to userspace using device
+files of the form ``/dev/gpiochipX``.
+
+Each chip supports a number of GPIO lines,
+:c:type:`chip.lines<gpiochip_info>`. Lines on the chip are identified by an
+``offset`` in the range from 0 to ``chip.lines - 1``, i.e. `[0,chip.lines)`.
+
+Lines are requested from the chip using gpio-v2-get-line-ioctl.rst
+and the resulting line request is used to access the GPIO chip's lines or
+monitor the lines for edge events.
+
+Within this documentation, the file descriptor returned by calling `open()`
+on the GPIO device file is referred to as ``chip_fd``.
+
+Operations
+----------
+
+The following operations may be performed on the chip:
+
+.. toctree::
+ :titlesonly:
+
+ Get Line <gpio-v2-get-line-ioctl>
+ Get Chip Info <gpio-get-chipinfo-ioctl>
+ Get Line Info <gpio-v2-get-lineinfo-ioctl>
+ Watch Line Info <gpio-v2-get-lineinfo-watch-ioctl>
+ Unwatch Line Info <gpio-get-lineinfo-unwatch-ioctl>
+ Read Line Info Changed Events <gpio-v2-lineinfo-changed-read>
+
+.. _gpio-v2-line-request:
+
+Line Request
+============
+
+Line requests are created by gpio-v2-get-line-ioctl.rst and provide
+access to a set of requested lines. The line request is exposed to userspace
+via the anonymous file descriptor returned in
+:c:type:`request.fd<gpio_v2_line_request>` by gpio-v2-get-line-ioctl.rst.
+
+Within this documentation, the line request file descriptor is referred to
+as ``req_fd``.
+
+Operations
+----------
+
+The following operations may be performed on the line request:
+
+.. toctree::
+ :titlesonly:
+
+ Get Line Values <gpio-v2-line-get-values-ioctl>
+ Set Line Values <gpio-v2-line-set-values-ioctl>
+ Read Line Edge Events <gpio-v2-line-event-read>
+ Reconfigure Lines <gpio-v2-line-set-config-ioctl>
+
+Types
+=====
+
+This section contains the structs and enums that are referenced by the API v2,
+as defined in ``include/uapi/linux/gpio.h``.
+
+.. kernel-doc:: include/uapi/linux/gpio.h
+ :identifiers:
+ gpio_v2_line_attr_id
+ gpio_v2_line_attribute
+ gpio_v2_line_changed_type
+ gpio_v2_line_config
+ gpio_v2_line_config_attribute
+ gpio_v2_line_event
+ gpio_v2_line_event_id
+ gpio_v2_line_flag
+ gpio_v2_line_info
+ gpio_v2_line_info_changed
+ gpio_v2_line_request
+ gpio_v2_line_values
+ gpiochip_info
+
+.. toctree::
+ :hidden:
+
+ error-codes