From nobody Tue Dec 2 02:19:58 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 626B636C5B8; Thu, 20 Nov 2025 17:04:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763658270; cv=none; b=QcCMxZL6amNMDFhfnvAxrLd2rkGNE8pe0NpgpToTbDOyjHQRjDCX3VuNFV2f4y83IKCOQmYX6NIU1DvlWuFkEqjlJZXNbb3GCMCzKQbP651gPIQGLLiDA3ab65ukB3RaIV0lr2bdnlBzP2FV+OWs90z8SDJso7h6QZN8SBQauDQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763658270; c=relaxed/simple; bh=tBekpthiQ63+sVQeAxYqbIcCsnnV2MHwSMvelKk34hk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=jSaHQl/9A8vX00rNiw+VCrTF5MmmQyxoaxYQ2a9Y7Qzm6igEsABst2euQ6TcHxaExDnlF8aU65TvR9FrNXUicsvAwE5pp5eWEKvCsghQWuQpuhz6IzhXbzFm3JT3zXl2TVG1ydGon+vV5QfnDEooAOk1qSZTLb8WyMctsdJy27A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=xDwB1pAz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="xDwB1pAz" Received: by smtp.kernel.org (Postfix) with ESMTPS id 015DAC19423; Thu, 20 Nov 2025 17:04:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux.dev; s=korg; t=1763658270; bh=tBekpthiQ63+sVQeAxYqbIcCsnnV2MHwSMvelKk34hk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=xDwB1pAzVWOp0Iu3B26ifqSwOlL1Tn7cLp/JJTKwapRsuqVC7Ggx/BSwpsHSFMD5S LRfY2j2JUDN31fwmjvw6LUG/PR3vznsg9IUzl3WYT63pnD8GomYVTwlPhTbzOxOepE 7ZhGqMehkjqgLsK2NT25FH6bllYRXI0ksLTKRp00= Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7D9CCF9C67; Thu, 20 Nov 2025 17:04:29 +0000 (UTC) From: Richard Leitner Date: Thu, 20 Nov 2025 18:04:23 +0100 Subject: [PATCH v9 3/8] Documentation: uAPI: media: add V4L2_CID_FLASH_{DURATION,STROBE_OE} Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20251120-ov9282-flash-strobe-v9-3-6c9e3a4301d7@linux.dev> References: <20251120-ov9282-flash-strobe-v9-0-6c9e3a4301d7@linux.dev> In-Reply-To: <20251120-ov9282-flash-strobe-v9-0-6c9e3a4301d7@linux.dev> To: Sakari Ailus , Dave Stevenson , Mauro Carvalho Chehab , Lee Jones , Pavel Machek , Laurent Pinchart Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, Richard Leitner , Hans Verkuil X-Mailer: b4 0.15-dev-a3fc8 X-Developer-Signature: v=1; a=ed25519-sha256; t=1763658268; l=3443; i=richard.leitner@linux.dev; s=20250225; h=from:subject:message-id; bh=tBekpthiQ63+sVQeAxYqbIcCsnnV2MHwSMvelKk34hk=; b=PrF3n1h9n7HI1En9GXwytLNh/GG8DiYMLV9mlLVe8MGCr3t0l5rPgsFe6WiYT1je1/pATjoQo rMADjuvZ4L+AiKM9fcNjuIUr+xssPToHDu7ZY04ydl7RyqDiphXC88J X-Developer-Key: i=richard.leitner@linux.dev; a=ed25519; pk=8hZNyyyQFqZ5ruVJsSGBSPIrmJpfDm5HwHU4QVOP1Pk= X-Endpoint-Received: by B4 Relay for richard.leitner@linux.dev/20250225 with auth_id=350 Add the new strobe duration and hardware strobe output enable to v4l uAPI documentation. Additionally add labels for cross-referencing v4l controls. Signed-off-by: Richard Leitner --- .../userspace-api/media/v4l/ext-ctrls-flash.rst | 42 ++++++++++++++++++= ++++ 1 file changed, 42 insertions(+) diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-flash.rst b/Do= cumentation/userspace-api/media/v4l/ext-ctrls-flash.rst index d22c5efb806a..7cf0d33e79ff 100644 --- a/Documentation/userspace-api/media/v4l/ext-ctrls-flash.rst +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-flash.rst @@ -57,6 +57,8 @@ Flash Control IDs ``V4L2_CID_FLASH_CLASS (class)`` The FLASH class descriptor. =20 +.. _v4l2-cid-flash-led-mode: + ``V4L2_CID_FLASH_LED_MODE (menu)`` Defines the mode of the flash LED, the high-power white LED attached to the flash controller. Setting this control may not be possible in @@ -80,6 +82,8 @@ Flash Control IDs =20 =20 =20 +.. _v4l2-cid-flash-strobe-source: + ``V4L2_CID_FLASH_STROBE_SOURCE (menu)`` Defines the source of the flash LED strobe. =20 @@ -96,6 +100,12 @@ Flash Control IDs - The flash strobe is triggered by an external source. Typically this is a sensor, which makes it possible to synchronise the flash strobe start to exposure start. + This method of controlling flash LED strobe has two additional + prerequisites: the strobe source's :ref:`strobe output + ` must be enabled (if available) + and the flash controller's :ref:`flash LED mode + ` must be set to + ``V4L2_FLASH_LED_MODE_FLASH``. =20 =20 =20 @@ -186,3 +196,35 @@ Flash Control IDs charged before strobing. LED flashes often require a cooldown period after strobe during which another strobe will not be possible. This is a read-only control. + +.. _v4l2-cid-flash-duration: + +``V4L2_CID_FLASH_DURATION (integer)`` + Duration of the flash strobe pulse generated by the strobe source, when + using external strobe. This control shall be implemented by the device + generating the hardware flash strobe signal, typically a camera sensor, + connected to a flash controller. + + The flash controllers :ref:`strobe source ` + must be configured to ``V4L2_FLASH_STROBE_SOURCE_EXTERNAL`` for this + mode of operation. For more details please also take a look at the + documentation there. + + The unit should be microseconds (=C2=B5s) if possible. + +.. _v4l2-cid-flash-strobe-oe: + +``V4L2_CID_FLASH_STROBE_OE (boolean)`` + Enables the output of a hardware strobe signal from the strobe source, + when using external strobe. This control shall be implemented by the d= evice + generating the hardware flash strobe signal, typically a camera sensor, + connected to a flash controller. + + Provided the signal generating device driver supports it, the length o= f the + strobe signal can be configured by adjusting its + :ref:`flash duration `. + + The flash controllers :ref:`strobe source ` + must be configured to ``V4L2_FLASH_STROBE_SOURCE_EXTERNAL`` for this + mode of operation. For more details please also take a look at the + documentation there. --=20 2.47.3