From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) (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 4221C2C11F6; Thu, 4 Sep 2025 08:44:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756975500; cv=none; b=hSxsklOXAEW2PmBGZ7RYcCBjMnk8R0FLEwOl4vky+iwdi9WfeUIUG2XGQlmmSQCgwoiHwjshqrBHBU5ESsZAc+VwDoVOEbB2jIpbwHWN+Dqg7gJXwkrIvHeLpZSZH1yj72QRWF/iuWuQEzJsnzpAydB9gG+OWC7QNK8ywl4pBLk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756975500; c=relaxed/simple; bh=gzetGRXPPEFaGfqJAQ6Chzwhs2gIrlbRduBmetQTYrY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=tI8jmt4xM9HxdsoLxPtjVjKSR0dzxveejQIGbGkkHQG2a5zE20/T67wSJExzZnpQminw6H8f8GD/1WkkSBVpixrCpmvU1U9EglugASZigCy38IIfeSeoSZgr3B6TznIdVfECfhsCac3QZk9S2MbnU2RGkHbFzEjhp8OEa1lmSMw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=m6bvvW3R; arc=none smtp.client-ip=192.198.163.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="m6bvvW3R" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1756975499; x=1788511499; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=gzetGRXPPEFaGfqJAQ6Chzwhs2gIrlbRduBmetQTYrY=; b=m6bvvW3Rom+DeuhxAKuIGPrKc89UY7KAXA3I7vWy1nyug+yc5r4v78ZD DPxZAYGVJr3bT2h1WN1DNGCySAFMrf8mHg+8Pg1jBvDoQlJ1213IXOq6M 00j3uUWMMxh5xA/QkNLmi+Laj2WquRC4GIidlCmG9UVtakPm4olsKhGxT 777dCUeIGpx8nkMMPLyChN3KuDLj1MgTAUUqtYw6nI6QOWe5xhNKbyJCg EQIVQ7we70bB1bF1Nu6rMaE+nIKZgwzu8ePzNYMucGedCZrQMCwlCrAPV bbbyBVmk+qIYkqcXf8cfhFrxX1T3i+ZTRKBYFFAP4qMF5RRb1U5gqLBT+ A==; X-CSE-ConnectionGUID: HW5VAqwcTQSYK3jPIFVeHA== X-CSE-MsgGUID: WY7bHa3aSPKAMJd1f7FSOw== X-IronPort-AV: E=McAfee;i="6800,10657,11542"; a="58520275" X-IronPort-AV: E=Sophos;i="6.18,237,1751266800"; d="scan'208";a="58520275" Received: from orviesa005.jf.intel.com ([10.64.159.145]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Sep 2025 01:44:58 -0700 X-CSE-ConnectionGUID: N3TxRB0xQP6c9RbJ1GcVrg== X-CSE-MsgGUID: aYx3EAAlQhmx5apJZHzVyw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,237,1751266800"; d="scan'208";a="177096940" Received: from agladkov-desk.ger.corp.intel.com (HELO kekkonen.fi.intel.com) ([10.245.244.92]) by orviesa005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Sep 2025 01:44:53 -0700 Received: from kekkonen.localdomain (localhost [IPv6:::1]) by kekkonen.fi.intel.com (Postfix) with SMTP id EBE7611FCC7; Thu, 04 Sep 2025 11:44:49 +0300 (EEST) Date: Thu, 4 Sep 2025 11:44:49 +0300 Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo From: Sakari Ailus To: Isaac Scott Cc: laurent.pinchart@ideasonboard.com, rmfrfs@gmail.com, martink@posteo.de, kernel@puri.sm, mchehab@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-media@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, hverkuil@kernel.org, nicolas.dufresne@collabora.com, tomi.valkeinen@ideasonboard.com, jonas@kwiboo.se, dan.scally+renesas@ideasonboard.com, m.szyprowski@samsung.com, mehdi.djait@linux.intel.com, niklas.soderlund+renesas@ragnatech.se Subject: Re: [PATCH v2 1/3] media: v4l: Add helper to get number of active lanes via a pad Message-ID: References: <20250903102243.1563527-1-isaac.scott@ideasonboard.com> <20250903102243.1563527-2-isaac.scott@ideasonboard.com> 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=us-ascii Content-Disposition: inline In-Reply-To: <20250903102243.1563527-2-isaac.scott@ideasonboard.com> Hi Isaac, Thanks for the update. On Wed, Sep 03, 2025 at 11:22:40AM +0100, Isaac Scott wrote: > Sometimes, users will not use all of the MIPI CSI 2 lanes available when > connecting to the MIPI CSI receiver of their device. Add a helper > function that checks the mbus_config for the device driver to allow > users to define the number of active data lanes through the > get_mbus_config op. > > If the driver does not implement this op, fall back to using the number > of data lanes specified in device tree. > > Signed-off-by: Isaac Scott > --- > drivers/media/v4l2-core/v4l2-common.c | 25 +++++++++++++++++++++++++ > include/media/v4l2-common.h | 1 + > 2 files changed, 26 insertions(+) > > diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c > index 6e585bc76367..8683107b3704 100644 > --- a/drivers/media/v4l2-core/v4l2-common.c > +++ b/drivers/media/v4l2-core/v4l2-common.c > @@ -571,6 +571,31 @@ s64 __v4l2_get_link_freq_pad(struct media_pad *pad, unsigned int mul, > return __v4l2_get_link_freq_ctrl(sd->ctrl_handler, mul, div); > } > EXPORT_SYMBOL_GPL(__v4l2_get_link_freq_pad); > + > +unsigned int v4l2_get_active_data_lanes(const struct media_pad *pad, unsigned int dt_lanes) This line would benefit from being wrapped. > +{ > + struct v4l2_mbus_config mbus_config = {}; > + struct v4l2_subdev *sd; > + unsigned int lanes; > + int ret; > + > + sd = media_entity_to_v4l2_subdev(pad->entity); > + ret = v4l2_subdev_call(sd, pad, get_mbus_config, pad->index, > + &mbus_config); > + if (ret < 0 && ret != -ENOIOCTLCMD) > + return ret; > + > + if (!mbus_config.bus.mipi_csi2.num_data_lanes) > + return dt_lanes; > + > + lanes = mbus_config.bus.mipi_csi2.num_data_lanes; > + > + if (lanes < 0 || lanes > dt_lanes) lanes is unsigned int so no need to check for less than 0. I might just not use a local variable for this, up to you. > + return -EINVAL; > + > + return lanes; > +} > +EXPORT_SYMBOL_GPL(v4l2_get_active_data_lanes); > #endif /* CONFIG_MEDIA_CONTROLLER */ > > /* > diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h > index 0a43f56578bc..3f8937260c76 100644 > --- a/include/media/v4l2-common.h > +++ b/include/media/v4l2-common.h > @@ -584,6 +584,7 @@ int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt, u32 pixelformat, > (pad, mul, div) > s64 __v4l2_get_link_freq_pad(struct media_pad *pad, unsigned int mul, > unsigned int div); Some kernel-doc documentation would be nice. > +unsigned int v4l2_get_active_data_lanes(const struct media_pad *pad, unsigned int dt_lanes); Please wrap this, too. > #else > #define v4l2_get_link_freq(handler, mul, div) \ > __v4l2_get_link_freq_ctrl(handler, mul, div) -- Kind regards, Sakari Ailus