From mboxrd@z Thu Jan 1 00:00:00 1970 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 DC1FCC7EE24 for ; Fri, 2 Jun 2023 10:42:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235481AbjFBKmc (ORCPT ); Fri, 2 Jun 2023 06:42:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235721AbjFBKmS (ORCPT ); Fri, 2 Jun 2023 06:42:18 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7500C10CF for ; Fri, 2 Jun 2023 03:41:48 -0700 (PDT) Received: from pendragon.ideasonboard.com (om126156168104.26.openmobile.ne.jp [126.156.168.104]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 37CF46E0; Fri, 2 Jun 2023 12:36:18 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1685702179; bh=2NWBeQ04SlrYJQ8Y9Kw5ol04Q9oFPX/bLY9r/UFMEJg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=h92k6hEKh5ZTMRpZi3UsCKvGRNyo1FaRsXmiMLvspAeEjrqMCQhM8Ww7VIr8godfT HoXRVUbzl1zbQJ+6yf1ys2vhirf5iCK9PxUjrNwU0jPIaJxnu1yJ/OTcrppKequZbg BN+IsNhTohHn1c6YH2gMYauKPnkZAA9NuT/NiJTE= Date: Fri, 2 Jun 2023 13:36:41 +0300 From: Laurent Pinchart To: Sakari Ailus Cc: linux-media@vger.kernel.org, tomi.valkeinen@ideasonboard.com, bingbu.cao@intel.com, hongju.wang@intel.com Subject: Re: [RFC 5/7] media: uapi: Add generic serial metadata mbus formats Message-ID: <20230602103641.GL19463@pendragon.ideasonboard.com> References: <20230505215257.60704-1-sakari.ailus@linux.intel.com> <20230505215257.60704-6-sakari.ailus@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230505215257.60704-6-sakari.ailus@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Sakari, Thank you for the patch. On Sat, May 06, 2023 at 12:52:55AM +0300, Sakari Ailus wrote: > Add generic serial metadata mbus formats. These formats describe data > width and packing but not the content itself. The reason for specifying > such formats is that the formats as such are fairly device specific but > they are still handled by CSI-2 receiver drivers that should not be aware > of device specific formats. What makes generic metadata formats possible > is that these formats are parsed by software only, after capturing the > data to system memory. > > Signed-off-by: Sakari Ailus > --- > .../media/v4l/subdev-formats.rst | 257 ++++++++++++++++++ > include/uapi/linux/media-bus-format.h | 9 + > 2 files changed, 266 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/subdev-formats.rst b/Documentation/userspace-api/media/v4l/subdev-formats.rst > index a3a35eeed708..1492fff58426 100644 > --- a/Documentation/userspace-api/media/v4l/subdev-formats.rst > +++ b/Documentation/userspace-api/media/v4l/subdev-formats.rst > @@ -8234,3 +8234,260 @@ The following table lists the existing metadata formats. > both sides of the link and the bus format is a fixed > metadata format that is not configurable from userspace. > Width and height will be set to 0 for this format. > + > +Generic Serial Metadata Formats > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > + > +Generic serial metadata formats are used on serial busses where the actual data s/busses/buses/ > +content is more or less device specific but the data is transmitted and received > +by multiple devices that do not process the data in any way, simply writing > +it to system memory for processing in software at the end of the pipeline. > + > +The more specific variant describing the actual data is used on the internal > +source pad of the originating sub-device. What do you mean by "more specific variant" here ? Please include an example in the documentation. I'm not sure I like mentioning internal source pads here, are we guaranteed that metadata will always originate from an internal source pad ? > + > +"b" in an array cell signifies a byte of data, followed by the number of byte > +and finally the bit number in subscript. "p" indicates a padding bit. > + > +.. _media-bus-format-generic-meta: > + > +.. cssclass: longtable > + > +.. flat-table:: Generic Serial Metadata Formats > + :header-rows: 2 > + :stub-columns: 0 > + > + * - Identifier > + - Code > + - > + - :cspan:`23` Data organization > + * - > + - > + - Bit > + - 23 > + - 22 > + - 21 > + - 20 > + - 19 > + - 18 > + - 17 > + - 16 > + - 15 > + - 14 > + - 13 > + - 12 > + - 11 > + - 10 > + - 9 > + - 8 > + - 7 > + - 6 > + - 5 > + - 4 > + - 3 > + - 2 > + - 1 > + - 0 > + * .. _MEDIA-BUS-FMT-META-1X8-8: > + > + - MEDIA_BUS_FMT_META_1X8_8 > + - 0x8001 > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - b0\ :sub:`7` > + - b0\ :sub:`6` > + - b0\ :sub:`5` > + - b0\ :sub:`4` > + - b0\ :sub:`3` > + - b0\ :sub:`2` > + - b0\ :sub:`1` > + - b0\ :sub:`0` > + * .. _MEDIA-BUS-FMT-META-1X8-10: > + > + - MEDIA_BUS_FMT_META_1X8_10 > + - 0x8002 > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - b0\ :sub:`7` > + - b0\ :sub:`6` > + - b0\ :sub:`5` > + - b0\ :sub:`4` > + - b0\ :sub:`3` > + - b0\ :sub:`2` > + - b0\ :sub:`1` > + - b0\ :sub:`0` > + - p > + - p > + * .. _MEDIA-BUS-FMT-META-1X8-12: > + > + - MEDIA_BUS_FMT_META_1X8_12 > + - 0x8003 > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - b0\ :sub:`7` > + - b0\ :sub:`6` > + - b0\ :sub:`5` > + - b0\ :sub:`4` > + - b0\ :sub:`3` > + - b0\ :sub:`2` > + - b0\ :sub:`1` > + - b0\ :sub:`0` > + - p > + - p > + - p > + - p > + * .. _MEDIA-BUS-FMT-META-1X8-14: > + > + - MEDIA_BUS_FMT_META_1X8_14 > + - 0x8004 > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - b0\ :sub:`7` > + - b0\ :sub:`6` > + - b0\ :sub:`5` > + - b0\ :sub:`4` > + - b0\ :sub:`3` > + - b0\ :sub:`2` > + - b0\ :sub:`1` > + - b0\ :sub:`0` > + - p > + - p > + - p > + - p > + - p > + - p > + * .. _MEDIA-BUS-FMT-META-1X8-16: > + > + - MEDIA_BUS_FMT_META_1X8_16 > + - 0x8005 > + - > + - > + - > + - > + - > + - > + - > + - > + - > + - b0\ :sub:`7` > + - b0\ :sub:`6` > + - b0\ :sub:`5` > + - b0\ :sub:`4` > + - b0\ :sub:`3` > + - b0\ :sub:`2` > + - b0\ :sub:`1` > + - b0\ :sub:`0` > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + * .. _MEDIA-BUS-FMT-META-1X8-20: > + > + - MEDIA_BUS_FMT_META_1X8_20 > + - 0x8007 > + - > + - > + - > + - > + - > + - b0\ :sub:`7` > + - b0\ :sub:`6` > + - b0\ :sub:`5` > + - b0\ :sub:`4` > + - b0\ :sub:`3` > + - b0\ :sub:`2` > + - b0\ :sub:`1` > + - b0\ :sub:`0` > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + * .. _MEDIA-BUS-FMT-META-1X8-24: > + > + - MEDIA_BUS_FMT_META_1X8_24 > + - 0x8009 > + - > + - b0\ :sub:`7` > + - b0\ :sub:`6` > + - b0\ :sub:`5` > + - b0\ :sub:`4` > + - b0\ :sub:`3` > + - b0\ :sub:`2` > + - b0\ :sub:`1` > + - b0\ :sub:`0` > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > + - p > diff --git a/include/uapi/linux/media-bus-format.h b/include/uapi/linux/media-bus-format.h > index a03c543cb072..722463523bbd 100644 > --- a/include/uapi/linux/media-bus-format.h > +++ b/include/uapi/linux/media-bus-format.h > @@ -173,4 +173,13 @@ > */ > #define MEDIA_BUS_FMT_METADATA_FIXED 0x7001 > > +/* Generic line based metadata formats for serial buses. Next is 0x800b. */ > +#define MEDIA_BUS_FMT_META_1X8_8 0x8001 > +#define MEDIA_BUS_FMT_META_1X8_10 0x8002 > +#define MEDIA_BUS_FMT_META_1X8_12 0x8003 > +#define MEDIA_BUS_FMT_META_1X8_14 0x8004 > +#define MEDIA_BUS_FMT_META_1X8_16 0x8005 > +#define MEDIA_BUS_FMT_META_1X8_20 0x8007 > +#define MEDIA_BUS_FMT_META_1X8_24 0x8009 We've discussed this before privately, it's time to come to a conclusion :-) My preference would be #define MEDIA_BUS_FMT_META_RAW8 0x8001 #define MEDIA_BUS_FMT_META_RAW10 0x8002 #define MEDIA_BUS_FMT_META_RAW12 0x8003 #define MEDIA_BUS_FMT_META_RAW14 0x8004 #define MEDIA_BUS_FMT_META_RAW16 0x8005 #define MEDIA_BUS_FMT_META_RAW20 0x8007 #define MEDIA_BUS_FMT_META_RAW24 0x8009 without defining the contents of the data (that is, no mention of padding bits). > + > #endif /* __LINUX_MEDIA_BUS_FORMAT_H */ -- Regards, Laurent Pinchart