From patchwork Thu Jul 27 05:42:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 707368 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49AE9EB64DD for ; Thu, 27 Jul 2023 05:47:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232406AbjG0FrJ (ORCPT ); Thu, 27 Jul 2023 01:47:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232397AbjG0Fqv (ORCPT ); Thu, 27 Jul 2023 01:46:51 -0400 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1D2D30C0 for ; Wed, 26 Jul 2023 22:46:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1690436769; x=1721972769; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dvXeObm01cacBHkSeEi8+dxxH50yIwH4oxysJ+x7xn0=; b=FM8aoY8U/c8rdRpovBCoYCuj5lBPGTD6sXc/NRe4CgNRbdbCXzU6Tnof GA8INE5JBnetrW7Ga40DL6PtQCibc5P6jS5ye4l7LcBI3Ey6WpB7gJu+n y5oeAdOByhieTmZcrgz+tt+lq5PvvkxZ/6IvmaMKTkePtPx2rCmXfZC5I ouRGtK7zCVdWCAZw3GP1op9CI9vUFNNuZsYxNgqNCnvyK/jQ76bhs6d2r GtvBwbfCYdmhI1el/inhYNcXWEHqAnJT0jNpVJ0J/DGCH1tSsblG9LreO haBLBCUiwlH7hycEy7mgKteWGr8Mt+z0RRs09yw3DX2XyNzcG+OJEanWW A==; X-IronPort-AV: E=McAfee;i="6600,9927,10783"; a="399150472" X-IronPort-AV: E=Sophos;i="6.01,234,1684825200"; d="scan'208";a="399150472" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jul 2023 22:44:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10783"; a="840584037" X-IronPort-AV: E=Sophos;i="6.01,234,1684825200"; d="scan'208";a="840584037" Received: from turnipsi.fi.intel.com (HELO kekkonen.fi.intel.com) ([10.237.72.44]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jul 2023 22:44:30 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by kekkonen.fi.intel.com (Postfix) with ESMTP id 89E18120AB8; Thu, 27 Jul 2023 08:44:18 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.96) (envelope-from ) id 1qOtmD-004xqi-2W; Thu, 27 Jul 2023 08:43:05 +0300 From: Sakari Ailus To: linux-media@vger.kernel.org Cc: laurent.pinchart@ideasonboard.com, Philipp Zabel , hverkuil@xs4all.nl, Francesco Dolcini , aishwarya.kothari@toradex.com, Robert Foss , Todor Tomov , Hyun Kwon , bingbu.cao@intel.com, niklas.soderlund@ragnatech.se, Kieran Bingham , Benjamin Mugnier , Sylvain Petinot , Eugen Hristev , Nicolas Ferre , Maxime Ripard , Rui Miguel Silva , Fabio Estevam , Bryan O'Donoghue , Sylwester Nawrocki , Dafna Hirschfeld , Hugues Fruchet , Yong Deng , Paul Kocialkowski , "Lad, Prabhakar" , Benoit Parrot , Steve Longerbeam , Thierry Reding , Jonathan Hunter , Sowjanya Komatineni , Marco Felsch Subject: [PATCH v6 07/38] media: Documentation: v4l: Add section titles for async Date: Thu, 27 Jul 2023 08:42:24 +0300 Message-Id: <20230727054255.1183255-8-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230727054255.1183255-1-sakari.ailus@linux.intel.com> References: <20230727054255.1183255-1-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Add section titles for async documentation. While the documentation is mostly fine as-is, it has grown from its original state but remains without internal structure. Add it now. Also remove an extra newline. Signed-off-by: Sakari Ailus Tested-by: Lad Prabhakar # Renesas RZ/G2L SMARC --- .../driver-api/media/v4l2-subdev.rst | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/Documentation/driver-api/media/v4l2-subdev.rst b/Documentation/driver-api/media/v4l2-subdev.rst index c46511c9b6c8..3cc56ac8d221 100644 --- a/Documentation/driver-api/media/v4l2-subdev.rst +++ b/Documentation/driver-api/media/v4l2-subdev.rst @@ -157,6 +157,9 @@ below. Using one or the other registration method only affects the probing process, the run-time bridge-subdevice interaction is in both cases the same. +Registering synchronous sub-devices +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + In the **synchronous** case a device (bridge) driver needs to register the :c:type:`v4l2_subdev` with the v4l2_device: @@ -175,10 +178,12 @@ You can unregister a sub-device using: :c:func:`v4l2_device_unregister_subdev ` (:c:type:`sd `). - Afterwards the subdev module can be unloaded and :c:type:`sd `->dev == ``NULL``. +Registering asynchronous sub-devices +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + In the **asynchronous** case subdevice probing can be invoked independently of the bridge driver availability. The subdevice driver then has to verify whether all the requirements for a successful probing are satisfied. This can include a @@ -190,6 +195,9 @@ performed using the :c:func:`v4l2_async_unregister_subdev` call. Subdevices registered this way are stored in a global list of subdevices, ready to be picked up by bridge drivers. +Asynchronous sub-device notifiers +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + Bridge drivers in turn have to register a notifier object. This is performed using the :c:func:`v4l2_async_nf_register` call. To unregister the notifier the driver has to call @@ -208,12 +216,18 @@ the needs of the driver. :c:func:`v4l2_async_nf_add_i2c` are for bridge and ISP drivers for registering their async sub-devices with the notifier. +Asynchronous sub-device registration helper for camera sensor drivers +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + :c:func:`v4l2_async_register_subdev_sensor` is a helper function for sensor drivers registering their own async sub-device, but it also registers a notifier and further registers async sub-devices for lens and flash devices found in firmware. The notifier for the sub-device is unregistered with the async sub-device. +Asynchronous sub-device notifier example +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + These functions allocate an async sub-device descriptor which is of type struct :c:type:`v4l2_async_subdev` embedded in a driver-specific struct. The &struct :c:type:`v4l2_async_subdev` shall be the first member of this struct: @@ -237,6 +251,9 @@ These functions allocate an async sub-device descriptor which is of type struct if (IS_ERR(my_asd)) return PTR_ERR(my_asd); +Asynchronous sub-device notifier callbacks +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + The V4L2 core will then use these descriptors to match asynchronously registered subdevices to them. If a match is detected the ``.bound()`` notifier callback is called. After all subdevices have been located the