{"id":10890,"url":"https://patchwork.libcamera.org/api/patches/10890/?format=json","web_url":"https://patchwork.libcamera.org/patch/10890/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20210119143711.153517-3-jacopo@jmondi.org>","date":"2021-01-19T14:37:02","name":"[libcamera-devel,v2,02/11] libcamera: camera_sensor: Make V4L2_CID_EXPOSURE mandatory","commit_ref":null,"pull_url":null,"state":"accepted","archived":false,"hash":"075d158ee656d5dbe464307a0da08bdc65e6fc58","submitter":{"id":3,"url":"https://patchwork.libcamera.org/api/people/3/?format=json","name":"Jacopo Mondi","email":"jacopo@jmondi.org"},"delegate":{"id":15,"url":"https://patchwork.libcamera.org/api/users/15/?format=json","username":"jmondi","first_name":"Jacopo","last_name":"Mondi","email":"jacopo@jmondi.org"},"mbox":"https://patchwork.libcamera.org/patch/10890/mbox/","series":[{"id":1584,"url":"https://patchwork.libcamera.org/api/series/1584/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=1584","date":"2021-01-19T14:37:00","name":"android: Exposure times + scaler crop + android metadata","version":2,"mbox":"https://patchwork.libcamera.org/series/1584/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/10890/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/10890/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id B6A23BD808\n\tfor ;\n\tTue, 19 Jan 2021 14:37:00 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 8A9406815A;\n\tTue, 19 Jan 2021 15:37:00 +0100 (CET)","from relay6-d.mail.gandi.net (relay6-d.mail.gandi.net\n\t[217.70.183.198])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 0AE9568140\n\tfor ;\n\tTue, 19 Jan 2021 15:36:58 +0100 (CET)","from uno.LocalDomain (93-61-96-190.ip145.fastwebnet.it\n\t[93.61.96.190]) (Authenticated sender: jacopo@jmondi.org)\n\tby relay6-d.mail.gandi.net (Postfix) with ESMTPSA id AF004C001E\n\tfor ;\n\tTue, 19 Jan 2021 14:36:57 +0000 (UTC)"],"X-Originating-IP":"93.61.96.190","From":"Jacopo Mondi ","To":"libcamera-devel@lists.libcamera.org","Date":"Tue, 19 Jan 2021 15:37:02 +0100","Message-Id":"<20210119143711.153517-3-jacopo@jmondi.org>","X-Mailer":"git-send-email 2.29.2","In-Reply-To":"<20210119143711.153517-1-jacopo@jmondi.org>","References":"<20210119143711.153517-1-jacopo@jmondi.org>","MIME-Version":"1.0","Subject":"[libcamera-devel] [PATCH v2 02/11] libcamera: camera_sensor: Make\n\tV4L2_CID_EXPOSURE mandatory","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"Add the V4L2_CID_EXPOSURE control to the list of mandatory controls the\nsensor driver has to report and document this new requirement.\n\nWhile at it, re-sort the mandatory V4L2 controls in alphabetical\norder in the CameraSensor class.\n\nReviewed-by: Laurent Pinchart \nSigned-off-by: Jacopo Mondi \n---\n Documentation/sensor_driver_requirements.rst | 11 ++++++++++-\n src/libcamera/camera_sensor.cpp | 3 ++-\n 2 files changed, 12 insertions(+), 2 deletions(-)","diff":"diff --git a/Documentation/sensor_driver_requirements.rst b/Documentation/sensor_driver_requirements.rst\nindex 0e658aaa03b5..187f1c921dbf 100644\n--- a/Documentation/sensor_driver_requirements.rst\n+++ b/Documentation/sensor_driver_requirements.rst\n@@ -24,13 +24,22 @@ The sensor driver is assumed to be fully compliant with the V4L2 specification.\n \n The sensor driver shall support the following V4L2 controls:\n \n+* `V4L2_CID_EXPOSURE`_\n * `V4L2_CID_HBLANK`_\n * `V4L2_CID_PIXEL_RATE`_\n \n+.. _V4L2_CID_EXPOSURE: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/control.html\n .. _V4L2_CID_HBLANK: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-image-source.html\n .. _V4L2_CID_PIXEL_RATE: https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/ext-ctrls-image-process.html\n \n-Both controls are used to compute the sensor output timings.\n+The `EXPOSURE` control shall report the image integration time in number of\n+lines. While V4L2 doesn't specify a unit for the `EXPOSURE` control, libcamera\n+requires it to be expressed as a number of image lines. Camera sensor drivers\n+that do not comply with this requirement will need to be adapted or will produce\n+incorrect results.\n+\n+The `HBLANK` and `PIXEL_RATE` controls are used to compute the sensor output\n+timings.\n \n Optional Requirements\n ---------------------\ndiff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp\nindex 9abb9d330664..5774578fe61f 100644\n--- a/src/libcamera/camera_sensor.cpp\n+++ b/src/libcamera/camera_sensor.cpp\n@@ -243,8 +243,9 @@ int CameraSensor::validateSensorDriver()\n \t * - V4L2_CID_HBLANK is used to calculate the line length\n \t */\n \tconst std::vector mandatoryControls{\n-\t\tV4L2_CID_PIXEL_RATE,\n+\t\tV4L2_CID_EXPOSURE,\n \t\tV4L2_CID_HBLANK,\n+\t\tV4L2_CID_PIXEL_RATE,\n \t};\n \n \tControlList ctrls = subdev_->getControls(mandatoryControls);\n","prefixes":["libcamera-devel","v2","02/11"]}