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authorLinus 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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+=============
+uinput module
+=============
+
+Introduction
+============
+
+uinput is a kernel module that makes it possible to emulate input devices
+from userspace. By writing to /dev/uinput (or /dev/input/uinput) device, a
+process can create a virtual input device with specific capabilities. Once
+this virtual device is created, the process can send events through it,
+that will be delivered to userspace and in-kernel consumers.
+
+Interface
+=========
+
+::
+
+ linux/uinput.h
+
+The uinput header defines ioctls to create, set up, and destroy virtual
+devices.
+
+libevdev
+========
+
+libevdev is a wrapper library for evdev devices that provides interfaces to
+create uinput devices and send events. libevdev is less error-prone than
+accessing uinput directly, and should be considered for new software.
+
+For examples and more information about libevdev:
+https://www.freedesktop.org/software/libevdev/doc/latest/
+
+Examples
+========
+
+Keyboard events
+---------------
+
+This first example shows how to create a new virtual device, and how to
+send a key event. All default imports and error handlers were removed for
+the sake of simplicity.
+
+.. code-block:: c
+
+ #include <linux/uinput.h>
+
+ void emit(int fd, int type, int code, int val)
+ {
+ struct input_event ie;
+
+ ie.type = type;
+ ie.code = code;
+ ie.value = val;
+ /* timestamp values below are ignored */
+ ie.time.tv_sec = 0;
+ ie.time.tv_usec = 0;
+
+ write(fd, &ie, sizeof(ie));
+ }
+
+ int main(void)
+ {
+ struct uinput_setup usetup;
+
+ int fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
+
+
+ /*
+ * The ioctls below will enable the device that is about to be
+ * created, to pass key events, in this case the space key.
+ */
+ ioctl(fd, UI_SET_EVBIT, EV_KEY);
+ ioctl(fd, UI_SET_KEYBIT, KEY_SPACE);
+
+ memset(&usetup, 0, sizeof(usetup));
+ usetup.id.bustype = BUS_USB;
+ usetup.id.vendor = 0x1234; /* sample vendor */
+ usetup.id.product = 0x5678; /* sample product */
+ strcpy(usetup.name, "Example device");
+
+ ioctl(fd, UI_DEV_SETUP, &usetup);
+ ioctl(fd, UI_DEV_CREATE);
+
+ /*
+ * On UI_DEV_CREATE the kernel will create the device node for this
+ * device. We are inserting a pause here so that userspace has time
+ * to detect, initialize the new device, and can start listening to
+ * the event, otherwise it will not notice the event we are about
+ * to send. This pause is only needed in our example code!
+ */
+ sleep(1);
+
+ /* Key press, report the event, send key release, and report again */
+ emit(fd, EV_KEY, KEY_SPACE, 1);
+ emit(fd, EV_SYN, SYN_REPORT, 0);
+ emit(fd, EV_KEY, KEY_SPACE, 0);
+ emit(fd, EV_SYN, SYN_REPORT, 0);
+
+ /*
+ * Give userspace some time to read the events before we destroy the
+ * device with UI_DEV_DESTROY.
+ */
+ sleep(1);
+
+ ioctl(fd, UI_DEV_DESTROY);
+ close(fd);
+
+ return 0;
+ }
+
+Mouse movements
+---------------
+
+This example shows how to create a virtual device that behaves like a physical
+mouse.
+
+.. code-block:: c
+
+ #include <linux/uinput.h>
+
+ /* emit function is identical to of the first example */
+
+ int main(void)
+ {
+ struct uinput_setup usetup;
+ int i = 50;
+
+ int fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
+
+ /* enable mouse button left and relative events */
+ ioctl(fd, UI_SET_EVBIT, EV_KEY);
+ ioctl(fd, UI_SET_KEYBIT, BTN_LEFT);
+
+ ioctl(fd, UI_SET_EVBIT, EV_REL);
+ ioctl(fd, UI_SET_RELBIT, REL_X);
+ ioctl(fd, UI_SET_RELBIT, REL_Y);
+
+ memset(&usetup, 0, sizeof(usetup));
+ usetup.id.bustype = BUS_USB;
+ usetup.id.vendor = 0x1234; /* sample vendor */
+ usetup.id.product = 0x5678; /* sample product */
+ strcpy(usetup.name, "Example device");
+
+ ioctl(fd, UI_DEV_SETUP, &usetup);
+ ioctl(fd, UI_DEV_CREATE);
+
+ /*
+ * On UI_DEV_CREATE the kernel will create the device node for this
+ * device. We are inserting a pause here so that userspace has time
+ * to detect, initialize the new device, and can start listening to
+ * the event, otherwise it will not notice the event we are about
+ * to send. This pause is only needed in our example code!
+ */
+ sleep(1);
+
+ /* Move the mouse diagonally, 5 units per axis */
+ while (i--) {
+ emit(fd, EV_REL, REL_X, 5);
+ emit(fd, EV_REL, REL_Y, 5);
+ emit(fd, EV_SYN, SYN_REPORT, 0);
+ usleep(15000);
+ }
+
+ /*
+ * Give userspace some time to read the events before we destroy the
+ * device with UI_DEV_DESTROY.
+ */
+ sleep(1);
+
+ ioctl(fd, UI_DEV_DESTROY);
+ close(fd);
+
+ return 0;
+ }
+
+
+uinput old interface
+--------------------
+
+Before uinput version 5, there wasn't a dedicated ioctl to set up a virtual
+device. Programs supporting older versions of uinput interface need to fill
+a uinput_user_dev structure and write it to the uinput file descriptor to
+configure the new uinput device. New code should not use the old interface
+but interact with uinput via ioctl calls, or use libevdev.
+
+.. code-block:: c
+
+ #include <linux/uinput.h>
+
+ /* emit function is identical to of the first example */
+
+ int main(void)
+ {
+ struct uinput_user_dev uud;
+ int version, rc, fd;
+
+ fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
+ rc = ioctl(fd, UI_GET_VERSION, &version);
+
+ if (rc == 0 && version >= 5) {
+ /* use UI_DEV_SETUP */
+ return 0;
+ }
+
+ /*
+ * The ioctls below will enable the device that is about to be
+ * created, to pass key events, in this case the space key.
+ */
+ ioctl(fd, UI_SET_EVBIT, EV_KEY);
+ ioctl(fd, UI_SET_KEYBIT, KEY_SPACE);
+
+ memset(&uud, 0, sizeof(uud));
+ snprintf(uud.name, UINPUT_MAX_NAME_SIZE, "uinput old interface");
+ write(fd, &uud, sizeof(uud));
+
+ ioctl(fd, UI_DEV_CREATE);
+
+ /*
+ * On UI_DEV_CREATE the kernel will create the device node for this
+ * device. We are inserting a pause here so that userspace has time
+ * to detect, initialize the new device, and can start listening to
+ * the event, otherwise it will not notice the event we are about
+ * to send. This pause is only needed in our example code!
+ */
+ sleep(1);
+
+ /* Key press, report the event, send key release, and report again */
+ emit(fd, EV_KEY, KEY_SPACE, 1);
+ emit(fd, EV_SYN, SYN_REPORT, 0);
+ emit(fd, EV_KEY, KEY_SPACE, 0);
+ emit(fd, EV_SYN, SYN_REPORT, 0);
+
+ /*
+ * Give userspace some time to read the events before we destroy the
+ * device with UI_DEV_DESTROY.
+ */
+ sleep(1);
+
+ ioctl(fd, UI_DEV_DESTROY);
+
+ close(fd);
+ return 0;
+ }
+