From patchwork Mon Jul 17 13:18:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 704246 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 7440EC001B0 for ; Mon, 17 Jul 2023 13:21:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231591AbjGQNV6 (ORCPT ); Mon, 17 Jul 2023 09:21:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230266AbjGQNVi (ORCPT ); Mon, 17 Jul 2023 09:21:38 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F3D12117 for ; Mon, 17 Jul 2023 06:20:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689600056; x=1721136056; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=dvXeObm01cacBHkSeEi8+dxxH50yIwH4oxysJ+x7xn0=; b=VKPAir1wPgC2mxiog/9yWlnnsl0yKFa4+EOB84hoKmSyVC/eD8QS8Ncw 5C1CDkZaJtolen+m++EBqQU39FGVLvvker8GVKDhS5peqXNYmCPcmJcYZ ualYwwimgTmjU3O4Uh9g6saGZ/gVzYtf1z2YHmcbVJQu9hBF/5olQTcRc wyJhv+i66SLyrvpTLBrZKj357luwTW1bTTV37+gfMmaxw1hymrpuUSI+C lutiQtJvmVAmj/QZx2KD5alRSRI0z1wr7FSRsYWbw6i1NZ3KT/vRRnMIG 4MIQfnJ71OHemAGB3X05WCO5OVFmEum15iN/jtZslx/bD4Fuz7q2AJsHE w==; X-IronPort-AV: E=McAfee;i="6600,9927,10774"; a="432097447" X-IronPort-AV: E=Sophos;i="6.01,211,1684825200"; d="scan'208";a="432097447" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2023 06:20:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10774"; a="726541905" X-IronPort-AV: E=Sophos;i="6.01,211,1684825200"; d="scan'208";a="726541905" Received: from turnipsi.fi.intel.com (HELO kekkonen.fi.intel.com) ([10.237.72.44]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jul 2023 06:20:27 -0700 Received: from punajuuri.localdomain (punajuuri.localdomain [192.168.240.130]) by kekkonen.fi.intel.com (Postfix) with ESMTP id D5A96120D7C; Mon, 17 Jul 2023 16:20:15 +0300 (EEST) Received: from sailus by punajuuri.localdomain with local (Exim 4.96) (envelope-from ) id 1qLO8G-004s0K-01; Mon, 17 Jul 2023 16:19:20 +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 v5 07/38] media: Documentation: v4l: Add section titles for async Date: Mon, 17 Jul 2023 16:18:38 +0300 Message-Id: <20230717131909.1160787-8-sakari.ailus@linux.intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230717131909.1160787-1-sakari.ailus@linux.intel.com> References: <20230717131909.1160787-1-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