From: Philipp Zabel <p.zabel@pengutronix.de>
To: Russell King - ARM Linux <linux@armlinux.org.uk>
Cc: Steve Longerbeam <slongerbeam@gmail.com>,
Hans Verkuil <hverkuil@xs4all.nl>,
robh+dt@kernel.org, mark.rutland@arm.com, shawnguo@kernel.org,
kernel@pengutronix.de, fabio.estevam@nxp.com, mchehab@kernel.org,
nick@shmanahar.org, markus.heiser@darmarIT.de,
laurent.pinchart+renesas@ideasonboard.com, bparrot@ti.com,
geert@linux-m68k.org, arnd@arndb.de, sudipm.mukherjee@gmail.com,
minghsiu.tsai@mediatek.com, tiffany.lin@mediatek.com,
jean-christophe.trotin@st.com, horms+renesas@verge.net.au,
niklas.soderlund+renesas@ragnatech.se, robert.jarzmik@free.fr,
songjun.wu@microchip.com, andrew-ct.chen@mediatek.com,
gregkh@linuxfoundation.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-media@vger.kernel.org, devel@driverdev.osuosl.org,
Steve Longerbeam <steve_longerbeam@mentor.com>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Subject: Re: [PATCH v3 00/24] i.MX Media Driver
Date: Tue, 31 Jan 2017 11:09:24 +0100 [thread overview]
Message-ID: <1485857364.2932.27.camel@pengutronix.de> (raw)
In-Reply-To: <20170130130657.GR27312@n2100.armlinux.org.uk>
On Mon, 2017-01-30 at 13:06 +0000, Russell King - ARM Linux wrote:
> > The central issue seems to be that I think media pad links / media bus
> > formats should describe physical links, such as parallel or serial
> > buses, and the formats of pixels flowing through them, whereas Steve
> > would like to extend them to describe software transports and in-memory
> > formats.
>
> This probably isn't the right place to attach this comment in this
> thread, but... the issue of media bus formats matching physical buses
> is an argument that I think is already lost.
It is unfortunate that the parallel format definitions have been reused
for the MIPI logical formats, but I suppose we have to live with that.
Still, I think this is not a reason to open the floodgates and start
describing in-memory formats using MEDIA_BUS_FMT_*
Does at least the combination of logical format and number of lanes
uniquiely describe the physical format?
For the 4-lane LVDS bus formats there are JEIDA/VESA variants where just
the bit ordering is different (MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,
MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA).
> For example, take the 10-bit bayer formats:
>
> #define MEDIA_BUS_FMT_SBGGR10_1X10 0x3007
> #define MEDIA_BUS_FMT_SGBRG10_1X10 0x300e
> #define MEDIA_BUS_FMT_SGRBG10_1X10 0x300a
> #define MEDIA_BUS_FMT_SRGGB10_1X10 0x300f
>
> These are commonly used on CSI serial buses (see the smiapp driver for
> example). From the description at the top of the file, it says the
> 1X10 means that one pixel is transferred as one 10-bit sample.
>
> However, the format on wire is somewhat different - four pixels are
> transmitted over five bytes:
>
> P0 P1 P2 P3 P0 P1 P2 P3
> 8-bit 8-bit 8-bit 8-bit 2-bit 2-bit 2-bit 2-bit
>
> This gives two problems:
> 1) it doesn't fit in any sensible kind of "one pixel transferred as
> N M-bit samples" description because the pixel/sample values
> (depending how you look at them) are broken up.
>
> 2) changing this will probably be a user visible change, as things
> like smiapp are already in use.
>
> So, I think what we actually have is the media bus formats describing
> the _logical_ bus format. Yes, one pixel is transferred as one 10-bit
> sample in this case.
Yes. I suppose one way to look at it is that the MIPI CSI-2 specified
formats are representations of corresponding parallel bus formats.
> To help illustrate my point, consider the difference between
> MEDIA_BUS_FMT_RGB565_1X16 and MEDIA_BUS_FMT_RGB565_2X8_BE or
> MEDIA_BUS_FMT_RGB565_2X8_LE. RGB565_1X16 means 1 pixel over an effective
> 16-bit wide bus (if it's not 16-bit, then it has to be broken up into
> separate "samples".) RGB565_2X8 means 1 pixel as two 8-bit samples.
>
> So, the 10-bit bayer is 1 pixel as 1.25 bytes. Or is it, over a serial
> bus. Using the RGB565 case, 10-bit bayer over a 4 lane CSI bus becomes
> interesting:
>
> first byte 2nd 3rd
> lane 1 P0 9:2 S0 P7 9:2
> lane 2 P1 9:2 P4 9:2 S1
> lane 3 P2 9:2 P5 9:2 P8 9:2
> lane 4 P3 9:2 P6 9:2 P9 9:2
>
> S0 = P0/P1/P2/P3 least significant two bits
> S1 = P4/P5/P6/P7 least significant two bits
>
> or 2 lane CSI:
> first byte 2nd 3rd 4th 5th
> lane 1 P0 9:2 P2 S0 P5 P7
> lane 2 P1 9:2 P3 P4 P6 S1
>
> or 1 lane CSI:
> lane 1 P0 P1 P2 P3 S0 P4 P5 P6 P7 S1 P8 P9 ...
These do look like three different media bus formats to me.
regards
Philipp
next prev parent reply other threads:[~2017-01-31 10:10 UTC|newest]
Thread overview: 185+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-07 2:11 [PATCH v3 00/24] i.MX Media Driver Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 01/24] [media] dt-bindings: Add bindings for i.MX media driver Steve Longerbeam
2017-01-13 11:55 ` Philipp Zabel
2017-01-13 19:03 ` Steve Longerbeam
2017-01-16 12:09 ` Philipp Zabel
2017-01-16 17:13 ` Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 02/24] ARM: dts: imx6qdl: Add compatible, clocks, irqs to MIPI CSI-2 node Steve Longerbeam
2017-01-13 11:57 ` Philipp Zabel
2017-01-13 22:40 ` Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 03/24] ARM: dts: imx6qdl: Add mipi_ipu1/2 multiplexers, mipi_csi, and their connections Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 04/24] ARM: dts: imx6qdl: add media device Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 05/24] ARM: dts: imx6qdl-sabrelite: remove erratum ERR006687 workaround Steve Longerbeam
2017-01-13 11:59 ` Philipp Zabel
2017-01-07 2:11 ` [PATCH v3 06/24] ARM: dts: imx6-sabrelite: add OV5642 and OV5640 camera sensors Steve Longerbeam
2017-01-13 12:03 ` Philipp Zabel
2017-01-13 23:04 ` Steve Longerbeam
2017-01-16 12:55 ` Philipp Zabel
2017-01-16 17:15 ` Steve Longerbeam
2017-02-05 15:17 ` Laurent Pinchart
2017-01-30 22:28 ` Russell King - ARM Linux
2017-01-30 22:51 ` Russell King - ARM Linux
2017-02-05 15:24 ` Laurent Pinchart
2017-02-05 15:37 ` Russell King - ARM Linux
2017-01-07 2:11 ` [PATCH v3 07/24] ARM: dts: imx6-sabresd: " Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 08/24] ARM: dts: imx6-sabreauto: create i2cmux for i2c3 Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 09/24] ARM: dts: imx6-sabreauto: add reset-gpios property for max7310_b Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 10/24] ARM: dts: imx6-sabreauto: add pinctrl for gpt input capture Steve Longerbeam
2017-01-12 19:37 ` Tim Harvey
2017-01-12 23:40 ` Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 11/24] ARM: dts: imx6-sabreauto: add the ADV7180 video decoder Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 12/24] add mux and video interface bridge entity functions Steve Longerbeam
2017-01-20 13:56 ` Hans Verkuil
2017-02-05 15:36 ` Laurent Pinchart
2017-02-06 10:27 ` Philipp Zabel
2017-01-07 2:11 ` [PATCH v3 13/24] platform: add video-multiplexer subdevice driver Steve Longerbeam
2017-01-10 5:35 ` Rob Herring
2017-01-20 14:03 ` Hans Verkuil
2017-01-24 12:02 ` Philipp Zabel
2017-01-25 2:07 ` Steve Longerbeam
2017-02-05 15:48 ` Laurent Pinchart
2017-02-06 9:50 ` Hans Verkuil
2017-02-06 22:33 ` Laurent Pinchart
2017-02-06 23:10 ` Steve Longerbeam
2017-02-07 10:26 ` Laurent Pinchart
2017-02-07 10:41 ` Philipp Zabel
2017-02-07 14:11 ` Laurent Pinchart
2017-02-07 13:36 ` Benoit Parrot
2017-02-07 20:50 ` Sakari Ailus
2017-02-07 23:04 ` Laurent Pinchart
2017-01-24 12:44 ` Javier Martinez Canillas
2017-01-26 1:22 ` Steve Longerbeam
2017-02-07 20:46 ` Sakari Ailus
2017-02-08 9:47 ` Philipp Zabel
2017-02-08 10:05 ` Laurent Pinchart
2017-01-07 2:11 ` [PATCH v3 14/24] UAPI: Add media UAPI Kbuild file Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 15/24] media: Add userspace header file for i.MX Steve Longerbeam
2017-01-13 12:05 ` Philipp Zabel
2017-01-13 23:13 ` Steve Longerbeam
2017-02-05 15:50 ` Laurent Pinchart
2017-01-07 2:11 ` [PATCH v3 16/24] media: Add i.MX media core driver Steve Longerbeam
2017-01-13 15:20 ` Philipp Zabel
2017-01-14 22:46 ` Steve Longerbeam
2017-01-16 13:47 ` Philipp Zabel
2017-01-23 2:31 ` Steve Longerbeam
2017-01-23 11:13 ` Philipp Zabel
2017-01-24 1:38 ` Steve Longerbeam
2017-01-24 1:45 ` Steve Longerbeam
2017-01-24 11:37 ` Philipp Zabel
2017-01-30 15:28 ` Russell King - ARM Linux
[not found] ` <2b1d2418-1ad4-6373-cb07-c3aeab48187f@gmail.com>
2017-01-19 1:44 ` Steve Longerbeam
2017-01-24 11:39 ` Philipp Zabel
2017-01-30 22:29 ` Russell King - ARM Linux
2017-02-02 22:44 ` Russell King - ARM Linux
2017-02-02 22:50 ` Russell King - ARM Linux
2017-02-07 1:54 ` Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 17/24] media: imx: Add CSI subdev driver Steve Longerbeam
2017-01-16 15:03 ` Philipp Zabel
2017-01-16 21:15 ` Steve Longerbeam
2017-01-30 22:29 ` Russell King - ARM Linux
2017-01-31 10:30 ` Russell King - ARM Linux
2017-01-31 11:20 ` Russell King - ARM Linux
2017-02-01 0:31 ` Steve Longerbeam
2017-02-01 0:58 ` Russell King - ARM Linux
2017-01-31 15:51 ` Philipp Zabel
2017-01-31 16:48 ` Philipp Zabel
2017-02-01 1:40 ` Steve Longerbeam
2017-02-07 16:18 ` [PATCH] media: imx: csi: fix crop rectangle reset in sink set_fmt Philipp Zabel
2017-01-07 2:11 ` [PATCH v3 18/24] media: imx: Add SMFC subdev driver Steve Longerbeam
2017-02-01 18:39 ` Russell King - ARM Linux
2017-02-01 18:52 ` Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 19/24] media: imx: Add IC subdev drivers Steve Longerbeam
2017-01-20 14:29 ` Hans Verkuil
2017-01-25 2:39 ` Steve Longerbeam
2017-01-30 22:29 ` Russell King - ARM Linux
2017-01-07 2:11 ` [PATCH v3 20/24] media: imx: Add Camera Interface subdev driver Steve Longerbeam
2017-01-20 14:38 ` Hans Verkuil
2017-01-24 2:15 ` Steve Longerbeam
2017-01-31 13:42 ` Russell King - ARM Linux
2017-01-31 18:21 ` Steve Longerbeam
2017-01-31 20:33 ` Russell King - ARM Linux
2017-01-31 21:55 ` Ian Arkver
2017-01-31 22:04 ` Russell King - ARM Linux
2017-01-31 22:33 ` Ian Arkver
2017-01-31 22:36 ` Steve Longerbeam
2017-01-31 23:30 ` Russell King - ARM Linux
2017-01-31 23:41 ` Steve Longerbeam
2017-02-02 22:35 ` Russell King - ARM Linux
2017-02-07 1:52 ` Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 21/24] media: imx: Add MIPI CSI-2 Receiver " Steve Longerbeam
2017-01-30 22:30 ` Russell King - ARM Linux
2017-01-31 0:01 ` Russell King - ARM Linux
2017-01-31 9:49 ` Philipp Zabel
2017-02-01 1:02 ` Steve Longerbeam
2017-02-01 1:13 ` Russell King - ARM Linux
2017-01-31 0:31 ` Russell King - ARM Linux
2017-01-31 2:11 ` Steve Longerbeam
2017-02-01 23:44 ` Russell King - ARM Linux
2017-02-02 0:04 ` Steve Longerbeam
2017-02-02 11:50 ` Philipp Zabel
2017-02-08 23:23 ` Steve Longerbeam
2017-02-08 23:42 ` Russell King - ARM Linux
2017-02-09 23:49 ` Steve Longerbeam
2017-02-09 23:51 ` Steve Longerbeam
2017-02-13 9:20 ` Philipp Zabel
2017-02-13 23:20 ` Steve Longerbeam
2017-02-14 16:59 ` Philipp Zabel
2017-02-09 9:43 ` Philipp Zabel
2017-01-07 2:11 ` [PATCH v3 22/24] media: imx: Add MIPI CSI-2 OV5640 sensor " Steve Longerbeam
2017-01-20 14:48 ` Hans Verkuil
2017-01-25 19:10 ` Steve Longerbeam
2017-01-30 23:29 ` Russell King - ARM Linux
2017-01-31 3:31 ` Steve Longerbeam
2017-02-02 10:36 ` Laurent Pinchart
2017-02-12 22:53 ` Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 23/24] media: imx: Add Parallel OV5642 " Steve Longerbeam
2017-01-07 2:11 ` [PATCH v3 24/24] ARM: imx_v6_v7_defconfig: Enable staging video4linux drivers Steve Longerbeam
2017-01-11 23:14 ` [PATCH v3 00/24] i.MX Media Driver Tim Harvey
2017-01-12 3:22 ` Steve Longerbeam
2017-01-20 13:52 ` Hans Verkuil
2017-01-20 16:31 ` Philipp Zabel
2017-01-20 18:40 ` Steve Longerbeam
2017-01-20 20:39 ` Hans Verkuil
2017-01-23 11:00 ` Philipp Zabel
2017-01-23 11:08 ` Hans Verkuil
2017-01-24 11:28 ` Philipp Zabel
2017-01-23 23:08 ` Steve Longerbeam
2017-01-24 11:27 ` Philipp Zabel
2017-01-28 19:27 ` Steve Longerbeam
2017-01-30 13:06 ` Russell King - ARM Linux
2017-01-31 10:09 ` Philipp Zabel [this message]
2017-01-31 13:14 ` Russell King - ARM Linux
2017-01-31 13:35 ` Philipp Zabel
2017-01-31 14:04 ` Russell King - ARM Linux
2017-01-31 0:45 ` Russell King - ARM Linux
2017-01-31 1:06 ` Russell King - ARM Linux
2017-01-31 2:06 ` Steve Longerbeam
2017-01-31 1:22 ` Steve Longerbeam
2017-01-31 9:49 ` Philipp Zabel
2017-01-31 10:21 ` Russell King - ARM Linux
2017-01-31 11:00 ` Russell King - ARM Linux
2017-01-31 23:43 ` Steve Longerbeam
2017-02-01 0:23 ` Russell King - ARM Linux
2017-02-01 1:54 ` Steve Longerbeam
2017-02-01 9:20 ` Russell King - ARM Linux
2017-01-31 13:54 ` Philipp Zabel
2017-01-31 14:25 ` Philipp Zabel
2017-01-31 15:03 ` Russell King - ARM Linux
2017-02-01 1:26 ` Steve Longerbeam
2017-02-01 9:30 ` Philipp Zabel
2017-02-01 10:11 ` Russell King - ARM Linux
2017-02-01 10:42 ` Philipp Zabel
2017-02-01 10:53 ` Russell King - ARM Linux
2017-02-02 0:19 ` Steve Longerbeam
2017-02-03 14:41 ` Laurent Pinchart
2017-02-03 17:56 ` Steve Longerbeam
2017-02-15 2:27 ` Steve Longerbeam
2017-02-15 9:33 ` Philipp Zabel
2017-02-02 17:22 ` Russell King - ARM Linux
2017-02-02 17:31 ` Steve Longerbeam
2017-02-02 17:56 ` Russell King - ARM Linux
2017-02-02 18:26 ` Steve Longerbeam
2017-02-02 18:58 ` Russell King - ARM Linux
2017-02-02 19:12 ` Steve Longerbeam
2017-02-02 22:29 ` Russell King - ARM Linux
2017-02-03 18:49 ` Steve Longerbeam
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1485857364.2932.27.camel@pengutronix.de \
--to=p.zabel@pengutronix.de \
--cc=andrew-ct.chen@mediatek.com \
--cc=arnd@arndb.de \
--cc=bparrot@ti.com \
--cc=devel@driverdev.osuosl.org \
--cc=devicetree@vger.kernel.org \
--cc=fabio.estevam@nxp.com \
--cc=geert@linux-m68k.org \
--cc=gregkh@linuxfoundation.org \
--cc=horms+renesas@verge.net.au \
--cc=hverkuil@xs4all.nl \
--cc=jean-christophe.trotin@st.com \
--cc=kernel@pengutronix.de \
--cc=laurent.pinchart+renesas@ideasonboard.com \
--cc=laurent.pinchart@ideasonboard.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=linux@armlinux.org.uk \
--cc=mark.rutland@arm.com \
--cc=markus.heiser@darmarIT.de \
--cc=mchehab@kernel.org \
--cc=minghsiu.tsai@mediatek.com \
--cc=nick@shmanahar.org \
--cc=niklas.soderlund+renesas@ragnatech.se \
--cc=robert.jarzmik@free.fr \
--cc=robh+dt@kernel.org \
--cc=shawnguo@kernel.org \
--cc=slongerbeam@gmail.com \
--cc=songjun.wu@microchip.com \
--cc=steve_longerbeam@mentor.com \
--cc=sudipm.mukherjee@gmail.com \
--cc=tiffany.lin@mediatek.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).