Re: [PATCH 04/14] media: add V4L2 DT binding documentation
Hi Guennadi, On Mon, Oct 08, 2012 at 09:58:58AM +0200, Guennadi Liakhovetski wrote: On Fri, 5 Oct 2012, Sascha Hauer wrote: On Fri, Oct 05, 2012 at 05:41:00PM +0200, Guennadi Liakhovetski wrote: Hi Sascha Maybe the example would be clearer if you split it up in two, one simple case with the csi2_1 - imx074_1 and a more advanced with the link in between. With no link between two ports no connection is possible, so, only examples with links make sense. I should have said with the renesas,sh-mobile-ceu in between. So simple example: csi2_1 -l- imx074_1 advanced: csi2_2 -l- ceu -l- ov772x No, CEU is the DMA engine with some image processing, so, it's always present. The CSI-2 is just a MIPI CSI-2 interface, that in the above case is used with the CEU too. So, it's like ,-l- ov772x / ceu0 \ `-l- csi2 -l- imx074 It took me some time until I figured out that these are two separate camera/sensor pairs. Somehow I was looking for a multiplexer between them. Maybe I can add more comments to the file, perhaps, add an ASCII-art chart. That would be good. Is the above good enough? :) Yes, thanks. We thought and disucssed about this devicetree binding quite much the last days. Finally I understood it and I must say that I like it. I think more prosa to explain the general concept would be good in the binding doc. Mark, when do we get the same for aSoC? ;) Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0| Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917- | -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Wed, Oct 10, 2012 at 10:40:06AM +0200, Sascha Hauer wrote: Mark, when do we get the same for aSoC? ;) Well, I'm unlikely to work on it as I don't have any systems which can boot with device tree. The big, big problem you've got doing this is lots of dynamic changes at runtime and in general complicated systems. It's trivial to describe the physical links but they don't provide anything like enough information to use things. Quite frankly I'm not sure device tree is a useful investment of time for advanced audio systems anyway, it's really not solving any problems people actually have. -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Wed, Oct 10, 2012 at 05:51:27PM +0900, Mark Brown wrote: On Wed, Oct 10, 2012 at 10:40:06AM +0200, Sascha Hauer wrote: Mark, when do we get the same for aSoC? ;) Well, I'm unlikely to work on it as I don't have any systems which can boot with device tree. If it's only that I'm sure we could spare a i.MX53 LOCO ;) The big, big problem you've got doing this is lots of dynamic changes at runtime and in general complicated systems. It's trivial to describe the physical links but they don't provide anything like enough information to use things. Quite frankly I'm not sure device tree is a useful investment of time for advanced audio systems anyway, it's really not solving any problems people actually have. Right now the i.MX audmux binding is only enough to say which ports should be connected, but not which format should be used. Just today we had the problem where a codec has two DAIs and wanted to add the information on which port our SSI unit is connected to the devicetree. So I think it's worthwile to do, but that would be a big big task... Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0| Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917- | -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Wed, Oct 10, 2012 at 11:21:15AM +0200, Sascha Hauer wrote: On Wed, Oct 10, 2012 at 05:51:27PM +0900, Mark Brown wrote: Well, I'm unlikely to work on it as I don't have any systems which can boot with device tree. If it's only that I'm sure we could spare a i.MX53 LOCO ;) Well, something with Wolfson hardware would be helpful. The big, big problem you've got doing this is lots of dynamic changes at runtime and in general complicated systems. It's trivial to describe the physical links but they don't provide anything like enough information to use things. Quite frankly I'm not sure device tree is a useful investment of time for advanced audio systems anyway, it's really not solving any problems people actually have. Right now the i.MX audmux binding is only enough to say which ports should be connected, but not which format should be used. Just today Why should that be in DT? For most things it's either fixed by the hardware or makes no odds. we had the problem where a codec has two DAIs and wanted to add the information on which port our SSI unit is connected to the devicetree. There's nothing stopping you doing that right now, the existing DT So I think it's worthwile to do, but that would be a big big task... For simple devices there's already stuff there and it's not hard to add new machine bindings, it's trying to cover the general case that's far too much effort. -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Mon 8 October 2012 23:14:01 Guennadi Liakhovetski wrote:
On Mon, 8 Oct 2012, Laurent Pinchart wrote:
On Monday 08 October 2012 14:00:38 Stephen Warren wrote:
On 10/02/2012 08:33 AM, Guennadi Liakhovetski wrote:
On Tue, 2 Oct 2012, Rob Herring wrote:
On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree
bindings.
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
One other comment below:
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors,
controlled +over an I2C, SPI or UART bus, and SoC internal IP blocks,
including video DMA +engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to
other SoC +blocks. External devices are represented as child nodes of
their respective bus +controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT
nodes. +Configuration of a port depends on other devices participating
in the data +transfer and is described by link DT nodes, specified
as
children of the +port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device
on
the same +bus, a link child DT node must be provided for each of
them. If more than one +port is present on a device or more than one
link is connected to a port, a +common scheme, using #address-cells,
#size-cells and reg properties is +used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
This name is a little vague. Perhaps endpoint would be better.
endpoint can also refer to something local like in USB case. Maybe
rather the description of the remote property should be improved?
The documentation doesn't show up in all the .dts files that use it; it
might be useful to try and make the .dts file as obviously readable as
possible.
Perhaps remote-port or connected-port would be sufficiently
descriptive.
I like remote-port better than the already proposed remote-link.
Yes, remote-port sounds better, than remote-link, but might be more
difficult to correlate with the fact, that the phandle value of this
property points to a link DT node, and not to a port.
I first thought of remote-port as well, but it is just weird that it points to
a link node.
I seem to remember that 'link' was called 'pad' initially, but people didn't
like that due to possible confusion with other meanings of that word.
The problem with the word 'link' is that it doesn't describe a link but just
one endpoint of a link.
Is it an idea to rename 'link' to 'endpoint' and 'remote' to 'remote-endpoint'?
So a port has endpoints, and each endpoint has a remote-endpoint property.
Regards,
Hans
--
To unsubscribe from this list: send the line unsubscribe linux-media in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Tue, 9 Oct 2012, Hans Verkuil wrote:
On Mon 8 October 2012 23:14:01 Guennadi Liakhovetski wrote:
On Mon, 8 Oct 2012, Laurent Pinchart wrote:
On Monday 08 October 2012 14:00:38 Stephen Warren wrote:
On 10/02/2012 08:33 AM, Guennadi Liakhovetski wrote:
On Tue, 2 Oct 2012, Rob Herring wrote:
On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree
bindings.
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
One other comment below:
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors,
controlled +over an I2C, SPI or UART bus, and SoC internal IP
blocks,
including video DMA +engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to
other SoC +blocks. External devices are represented as child nodes
of
their respective bus +controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child
DT
nodes. +Configuration of a port depends on other devices
participating
in the data +transfer and is described by link DT nodes,
specified as
children of the +port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other
device on
the same +bus, a link child DT node must be provided for each of
them. If more than one +port is present on a device or more than one
link is connected to a port, a +common scheme, using
#address-cells,
#size-cells and reg properties is +used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
This name is a little vague. Perhaps endpoint would be better.
endpoint can also refer to something local like in USB case. Maybe
rather the description of the remote property should be improved?
The documentation doesn't show up in all the .dts files that use it; it
might be useful to try and make the .dts file as obviously readable as
possible.
Perhaps remote-port or connected-port would be sufficiently
descriptive.
I like remote-port better than the already proposed remote-link.
Yes, remote-port sounds better, than remote-link, but might be more
difficult to correlate with the fact, that the phandle value of this
property points to a link DT node, and not to a port.
I first thought of remote-port as well, but it is just weird that it points to
a link node.
I seem to remember that 'link' was called 'pad' initially, but people didn't
like that due to possible confusion with other meanings of that word.
The problem with the word 'link' is that it doesn't describe a link but just
one endpoint of a link.
Is it an idea to rename 'link' to 'endpoint' and 'remote' to
'remote-endpoint'?
So a port has endpoints, and each endpoint has a remote-endpoint property.
I'm fine with that.
Thanks
Guennadi
Regards,
Hans
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
--
To unsubscribe from this list: send the line unsubscribe linux-media in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Fri, 5 Oct 2012, Sascha Hauer wrote:
On Fri, Oct 05, 2012 at 05:41:00PM +0200, Guennadi Liakhovetski wrote:
Hi Sascha
+
+ ceu0: ceu@0xfe91 {
+ compatible = renesas,sh-mobile-ceu;
+ reg = 0xfe91 0xa0;
+ interrupts = 0x880;
+
+ mclk: master_clock {
+ compatible = renesas,ceu-clock;
+ #clock-cells = 1;
+ clock-frequency = 5000; /* max clock
frequency */
+ clock-output-names = mclk;
+ };
+
+ port {
+ #address-cells = 1;
+ #size-cells = 0;
+
+ ceu0_1: link@1 {
+ reg = 1; /* local link #
*/
+ remote = ov772x_1_1; /* remote
phandle */
+ bus-width = 8;/* used data
lines */
+ data-shift = 0; /* lines 7:0
are used */
+
+ /* If [hv]sync-active are missing,
embedded bt.605 sync is used */
+ hsync-active = 1; /* active high
*/
+ vsync-active = 1; /* active high
*/
+ data-active = 1; /* active high
*/
+ pclk-sample = 1; /* rising */
+ };
+
+ ceu0_0: link@0 {
+ reg = 0;
+ remote = csi2_2;
+ immutable;
+ };
+ };
+ };
+
+ i2c0: i2c@0xfff2 {
+ ...
+ ov772x_1: camera@0x21 {
+ compatible = omnivision,ov772x;
+ reg = 0x21;
+ vddio-supply = regulator1;
+ vddcore-supply = regulator2;
+
+ clock-frequency = 2000;
+ clocks = mclk 0;
+ clock-names = xclk;
+
+ port {
+ /* With 1 link per port no need in
addresses */
+ ov772x_1_1: link {
+ bus-width = 8;
+ remote = ceu0_1;
+ hsync-active = 1;
+ vsync-active = 0; /* who
came up with an inverter here?... */
+ data-active = 1;
+ pclk-sample = 1;
+ };
I currently do not understand why these properties are both in the sensor
and in the link. What happens if they conflict? Are inverters assumed
like suggested above? I think the bus can only have a single bus-width,
why allow multiple bus widths here?
Yes, these nodes represent port configuration of each party on a certain
link. And they can differ in certain properties, like - as you correctly
notice - in the case, when there's an inverter on a line. As for other
properties, some of them must be identical, like bus-width, still, they
have to be provided on both ends, because generally drivers have to be
able to perform all the required configuration based only on the
information from their own nodes, without looking at remote partner node
properties.
So the port associated to the ov772x_1 only describes how to configure
the ov772x and it's up to me to make sure that this configuration
matches the partner device. If I don't then it won't work but soc-camera
will happily continue.
Ok, that's good, I thought there would be some kind of matching
mechanism take place here. It may be worth to make this more explicit in
the docs.
+ reg = 0xffc9 0x1000;
+ interrupts = 0x17a0;
+ #address-cells = 1;
+ #size-cells = 0;
+
+ port@1 {
+ compatible = renesas,csi2c; /* one of CSI2I
and CSI2C */
+ reg = 1; /* CSI-2 PHY #1
of 2: PHY_S, PHY_M has port address 0, is unused */
+
+ csi2_1: link {
+ clock-lanes = 0;
+ data-lanes = 2, 1;
+ remote = imx074_1;
+ };
+ };
+ port@2 {
+ reg = 2; /* port 2: link
to the CEU */
+
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On 10/02/2012 08:33 AM, Guennadi Liakhovetski wrote:
On Tue, 2 Oct 2012, Rob Herring wrote:
On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
One other comment below:
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors,
controlled
+over an I2C, SPI or UART bus, and SoC internal IP blocks, including video
DMA
+engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to other
SoC
+blocks. External devices are represented as child nodes of their
respective bus
+controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT
nodes.
+Configuration of a port depends on other devices participating in the data
+transfer and is described by link DT nodes, specified as children of the
+port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on the
same
+bus, a link child DT node must be provided for each of them. If more
than one
+port is present on a device or more than one link is connected to a port, a
+common scheme, using #address-cells, #size-cells and reg properties
is
+used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
This name is a little vague. Perhaps endpoint would be better.
endpoint can also refer to something local like in USB case. Maybe
rather the description of the remote property should be improved?
The documentation doesn't show up in all the .dts files that use it; it
might be useful to try and make the .dts file as obviously readable as
possible.
Perhaps remote-port or connected-port would be sufficiently descriptive.
(and yes, I know I'm probably bike-shedding now).
--
To unsubscribe from this list: send the line unsubscribe linux-media in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On 09/27/2012 08:07 AM, Guennadi Liakhovetski wrote: This patch adds a document, describing common V4L2 device tree bindings. Co-authored-by: Sylwester Nawrocki s.nawro...@samsung.com Signed-off-by: Guennadi Liakhovetski g.liakhovet...@gmx.de I think this looks reasonable now, touch wood:-) I guess I won't ack the binding until the v4l2 - something-generic rename happens, but I don't see anything stopping me from doing so once the rename happens. -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Monday 08 October 2012 14:00:38 Stephen Warren wrote:
On 10/02/2012 08:33 AM, Guennadi Liakhovetski wrote:
On Tue, 2 Oct 2012, Rob Herring wrote:
On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
One other comment below:
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors,
controlled +over an I2C, SPI or UART bus, and SoC internal IP blocks,
including video DMA +engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to
other SoC +blocks. External devices are represented as child nodes of
their respective bus +controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT
nodes. +Configuration of a port depends on other devices participating
in the data +transfer and is described by link DT nodes, specified as
children of the +port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on
the same +bus, a link child DT node must be provided for each of
them. If more than one +port is present on a device or more than one
link is connected to a port, a +common scheme, using #address-cells,
#size-cells and reg properties is +used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
This name is a little vague. Perhaps endpoint would be better.
endpoint can also refer to something local like in USB case. Maybe
rather the description of the remote property should be improved?
The documentation doesn't show up in all the .dts files that use it; it
might be useful to try and make the .dts file as obviously readable as
possible.
Perhaps remote-port or connected-port would be sufficiently descriptive.
I like remote-port better than the already proposed remote-link.
(and yes, I know I'm probably bike-shedding now).
--
Regards,
Laurent Pinchart
--
To unsubscribe from this list: send the line unsubscribe linux-media in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Mon, 8 Oct 2012, Laurent Pinchart wrote:
On Monday 08 October 2012 14:00:38 Stephen Warren wrote:
On 10/02/2012 08:33 AM, Guennadi Liakhovetski wrote:
On Tue, 2 Oct 2012, Rob Herring wrote:
On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
One other comment below:
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors,
controlled +over an I2C, SPI or UART bus, and SoC internal IP blocks,
including video DMA +engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to
other SoC +blocks. External devices are represented as child nodes of
their respective bus +controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT
nodes. +Configuration of a port depends on other devices participating
in the data +transfer and is described by link DT nodes, specified as
children of the +port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on
the same +bus, a link child DT node must be provided for each of
them. If more than one +port is present on a device or more than one
link is connected to a port, a +common scheme, using #address-cells,
#size-cells and reg properties is +used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
This name is a little vague. Perhaps endpoint would be better.
endpoint can also refer to something local like in USB case. Maybe
rather the description of the remote property should be improved?
The documentation doesn't show up in all the .dts files that use it; it
might be useful to try and make the .dts file as obviously readable as
possible.
Perhaps remote-port or connected-port would be sufficiently descriptive.
I like remote-port better than the already proposed remote-link.
Yes, remote-port sounds better, than remote-link, but might be more
difficult to correlate with the fact, that the phandle value of this
property points to a link DT node, and not to a port.
Thanks
Guennadi
(and yes, I know I'm probably bike-shedding now).
--
Regards,
Laurent Pinchart
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
--
To unsubscribe from this list: send the line unsubscribe linux-media in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Wed, 3 Oct 2012, Rob Herring wrote:
On 10/02/2012 09:33 AM, Guennadi Liakhovetski wrote:
Hi Rob
On Tue, 2 Oct 2012, Rob Herring wrote:
On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
Co-authored-by: Sylwester Nawrocki s.nawro...@samsung.com
Signed-off-by: Guennadi Liakhovetski g.liakhovet...@gmx.de
---
Documentation/devicetree/bindings/media/v4l2.txt | 162
++
1 files changed, 162 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/v4l2.txt
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
new file mode 100644
index 000..b8b3f41
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/v4l2.txt
@@ -0,0 +1,162 @@
+Video4Linux Version 2 (V4L2)
DT describes the h/w, but V4L2 is Linux specific. I think the binding
looks pretty good in terms of it is describing the h/w and not V4L2
components or settings. So in this case it's really just the name of the
file and title I have issue with.
Hm, I see your point, then, I guess, you'd also like the file name
changed. What should we use then? Just video? But there's already a
whole directory Documentation/devicetree/bindings/video dedicated to
graphics output (drm, fbdev). video-camera or video-capture? But this
file shall also be describing video output. Use video.txt and describe
inside what exactly this file is for?
Video output will probably have a lot of overlap with the graphics side.
How about video-interfaces.txt?
Hm, that's a bit too vague for me. Somewhere on the outskirts of my mind
I'm still considering making just one standard for both V4L2 and fbdev /
DRM? Just yesterday we were discussing some common properties with what is
being proposed in
http://www.mail-archive.com/linux-media@vger.kernel.org/index.html#53322
Still, I think, these two subsystems deserve two separate standards and
should just try to re-use properties wherever that makes sense.
video-stream seems a bit better, but this too is just a convention -
talking about video cameras and TV output as video streaming devices and
considering displays more static devices. In principle displays can be
considered taking streaming data just as well as TV encoders. What if we
just call this camera-tv.txt?
One other comment below:
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors,
controlled
+over an I2C, SPI or UART bus, and SoC internal IP blocks, including
video DMA
+engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to other
SoC
+blocks. External devices are represented as child nodes of their
respective bus
+controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT
nodes.
+Configuration of a port depends on other devices participating in the
data
+transfer and is described by link DT nodes, specified as children of
the
+port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on
the same
+bus, a link child DT node must be provided for each of them. If more
than one
+port is present on a device or more than one link is connected to a
port, a
+common scheme, using #address-cells, #size-cells and reg
properties is
+used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
This name is a little vague. Perhaps endpoint would be better.
endpoint can also refer to something local like in USB case. Maybe
rather the description of the remote property should be improved?
remote-endpoint?
Sorry, I really don't want to pull in yet another term here. We've got
ports and links already, now you're proposing to also use endpoind.
Until now everyone was happy with remote, any more opinions on this?
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
--
To unsubscribe from this list: send the line unsubscribe linux-media in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Fri October 5 2012 11:43:27 Guennadi Liakhovetski wrote:
On Wed, 3 Oct 2012, Rob Herring wrote:
On 10/02/2012 09:33 AM, Guennadi Liakhovetski wrote:
Hi Rob
On Tue, 2 Oct 2012, Rob Herring wrote:
On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
Co-authored-by: Sylwester Nawrocki s.nawro...@samsung.com
Signed-off-by: Guennadi Liakhovetski g.liakhovet...@gmx.de
---
Documentation/devicetree/bindings/media/v4l2.txt | 162
++
1 files changed, 162 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/v4l2.txt
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
new file mode 100644
index 000..b8b3f41
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/v4l2.txt
@@ -0,0 +1,162 @@
+Video4Linux Version 2 (V4L2)
DT describes the h/w, but V4L2 is Linux specific. I think the binding
looks pretty good in terms of it is describing the h/w and not V4L2
components or settings. So in this case it's really just the name of the
file and title I have issue with.
Hm, I see your point, then, I guess, you'd also like the file name
changed. What should we use then? Just video? But there's already a
whole directory Documentation/devicetree/bindings/video dedicated to
graphics output (drm, fbdev). video-camera or video-capture? But this
file shall also be describing video output. Use video.txt and describe
inside what exactly this file is for?
Video output will probably have a lot of overlap with the graphics side.
How about video-interfaces.txt?
Hm, that's a bit too vague for me. Somewhere on the outskirts of my mind
I'm still considering making just one standard for both V4L2 and fbdev /
DRM? Just yesterday we were discussing some common properties with what is
being proposed in
http://www.mail-archive.com/linux-media@vger.kernel.org/index.html#53322
Still, I think, these two subsystems deserve two separate standards and
should just try to re-use properties wherever that makes sense.
video-stream seems a bit better, but this too is just a convention -
talking about video cameras and TV output as video streaming devices and
considering displays more static devices. In principle displays can be
considered taking streaming data just as well as TV encoders. What if we
just call this camera-tv.txt?
One other comment below:
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors,
controlled
+over an I2C, SPI or UART bus, and SoC internal IP blocks, including
video DMA
+engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to
other SoC
+blocks. External devices are represented as child nodes of their
respective bus
+controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT
nodes.
+Configuration of a port depends on other devices participating in the
data
+transfer and is described by link DT nodes, specified as children of
the
+port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on
the same
+bus, a link child DT node must be provided for each of them. If more
than one
+port is present on a device or more than one link is connected to a
port, a
+common scheme, using #address-cells, #size-cells and reg
properties is
+used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
This name is a little vague. Perhaps endpoint would be better.
endpoint can also refer to something local like in USB case. Maybe
rather the description of the remote property should be improved?
remote-endpoint?
Sorry, I really don't want to pull in yet another term here. We've got
ports and links already, now you're proposing to also use endpoind.
Until now everyone was happy with remote, any more opinions on this?
Actually, when I was reviewing the patch series today I got confused as
well by 'remote'. What about 'remote-link'?
And v4l2_of_get_remote() can be renamed to v4l2_of_get_remote_link() which
I think is a lot clearer.
The text can be improved as well since this:
- remote: phandle to the other endpoint link DT node.
is a bit vague. How about:
- remote-link: phandle to the remote end of this link.
Regards,
Hans
--
To unsubscribe from this list: send the line unsubscribe linux-media in
the body of a message to majord...@vger.kernel.org
More majordomo info at
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Fri, 5 Oct 2012, Hans Verkuil wrote: On Fri October 5 2012 11:43:27 Guennadi Liakhovetski wrote: On Wed, 3 Oct 2012, Rob Herring wrote: On 10/02/2012 09:33 AM, Guennadi Liakhovetski wrote: Hi Rob On Tue, 2 Oct 2012, Rob Herring wrote: On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote: [snip] +Optional link properties: +- remote: phandle to the other endpoint link DT node. This name is a little vague. Perhaps endpoint would be better. endpoint can also refer to something local like in USB case. Maybe rather the description of the remote property should be improved? remote-endpoint? Sorry, I really don't want to pull in yet another term here. We've got ports and links already, now you're proposing to also use endpoind. Until now everyone was happy with remote, any more opinions on this? Actually, when I was reviewing the patch series today I got confused as well by 'remote'. What about 'remote-link'? Yes, I was thinking about this one too, it looks a bit clumsy, but it does make it clearer, what is meant. And v4l2_of_get_remote() can be renamed to v4l2_of_get_remote_link() which I think is a lot clearer. The text can be improved as well since this: - remote: phandle to the other endpoint link DT node. is a bit vague. How about: - remote-link: phandle to the remote end of this link. Looks good to me. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
Hi Guennadi,
Some comments inline.
On Thu, Sep 27, 2012 at 04:07:23PM +0200, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
Co-authored-by: Sylwester Nawrocki s.nawro...@samsung.com
Signed-off-by: Guennadi Liakhovetski g.liakhovet...@gmx.de
---
Documentation/devicetree/bindings/media/v4l2.txt | 162
++
1 files changed, 162 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/v4l2.txt
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
new file mode 100644
index 000..b8b3f41
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/v4l2.txt
@@ -0,0 +1,162 @@
+Video4Linux Version 2 (V4L2)
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors, controlled
+over an I2C, SPI or UART bus, and SoC internal IP blocks, including video DMA
+engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to other SoC
+blocks. External devices are represented as child nodes of their respective
bus
+controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT nodes.
+Configuration of a port depends on other devices participating in the data
+transfer and is described by link DT nodes, specified as children of the
+port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on the
same
+bus, a link child DT node must be provided for each of them. If more than
one
+port is present on a device or more than one link is connected to a port, a
+common scheme, using #address-cells, #size-cells and reg properties is
+used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
+- slave-mode: a boolean property, run the link in slave mode. Default is
master
+ mode.
+- data-shift: on parallel data busses, if data-width is used to specify the
+ number of data lines, data-shift can be used to specify which data lines
are
+ used, e.g. data-width=10; data-shift=2; means, that lines 9:2 are
used.
+- hsync-active: 1 or 0 for active-high or -low HSYNC signal polarity
+ respectively.
+- vsync-active: ditto for VSYNC. Note, that if HSYNC and VSYNC polarities are
+ not specified, embedded synchronisation may be required, where supported.
+- data-active: similar to HSYNC and VSYNC specifies data line polarity.
+- field-even-active: field signal level during the even field data
transmission.
+- pclk-sample: rising (1) or falling (0) edge to sample the pixel clock pin.
+- data-lanes: array of serial, e.g. MIPI CSI-2, data hardware lane numbers in
+ the ascending order, beginning with logical lane 0.
+- clock-lanes: hardware lane number, used for the clock lane.
+- clock-noncontinuous: a boolean property to allow MIPI CSI-2 non-continuous
+ clock mode.
+
+Example:
+
+ ceu0: ceu@0xfe91 {
+ compatible = renesas,sh-mobile-ceu;
+ reg = 0xfe91 0xa0;
+ interrupts = 0x880;
+
+ mclk: master_clock {
+ compatible = renesas,ceu-clock;
+ #clock-cells = 1;
+ clock-frequency = 5000; /* max clock frequency
*/
+ clock-output-names = mclk;
+ };
+
+ port {
+ #address-cells = 1;
+ #size-cells = 0;
+
+ ceu0_1: link@1 {
+ reg = 1; /* local link # */
+ remote = ov772x_1_1; /* remote phandle */
+ bus-width = 8;/* used data lines */
+ data-shift = 0; /* lines 7:0 are used */
+
+ /* If [hv]sync-active are missing, embedded
bt.605 sync is used */
+ hsync-active = 1; /* active high */
+ vsync-active = 1; /* active high */
+ data-active = 1; /* active high */
+ pclk-sample = 1; /* rising */
+ };
+
+ ceu0_0: link@0 {
+ reg = 0;
+ remote = csi2_2;
+ immutable;
+ };
+ };
+ };
+
+ i2c0: i2c@0xfff2 {
+ ...
+ ov772x_1: camera@0x21 {
+ compatible = omnivision,ov772x;
+ reg = 0x21;
+ vddio-supply = regulator1;
+ vddcore-supply = regulator2;
+
+
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
Hi Sascha
On Fri, 5 Oct 2012, Sascha Hauer wrote:
Hi Guennadi,
Some comments inline.
On Thu, Sep 27, 2012 at 04:07:23PM +0200, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
Co-authored-by: Sylwester Nawrocki s.nawro...@samsung.com
Signed-off-by: Guennadi Liakhovetski g.liakhovet...@gmx.de
---
Documentation/devicetree/bindings/media/v4l2.txt | 162
++
1 files changed, 162 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/v4l2.txt
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
new file mode 100644
index 000..b8b3f41
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/v4l2.txt
@@ -0,0 +1,162 @@
+Video4Linux Version 2 (V4L2)
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors,
controlled
+over an I2C, SPI or UART bus, and SoC internal IP blocks, including video
DMA
+engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to other
SoC
+blocks. External devices are represented as child nodes of their
respective bus
+controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT
nodes.
+Configuration of a port depends on other devices participating in the data
+transfer and is described by link DT nodes, specified as children of the
+port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on the
same
+bus, a link child DT node must be provided for each of them. If more
than one
+port is present on a device or more than one link is connected to a port, a
+common scheme, using #address-cells, #size-cells and reg properties
is
+used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
+- slave-mode: a boolean property, run the link in slave mode. Default is
master
+ mode.
+- data-shift: on parallel data busses, if data-width is used to specify the
+ number of data lines, data-shift can be used to specify which data lines
are
+ used, e.g. data-width=10; data-shift=2; means, that lines 9:2 are
used.
+- hsync-active: 1 or 0 for active-high or -low HSYNC signal polarity
+ respectively.
+- vsync-active: ditto for VSYNC. Note, that if HSYNC and VSYNC polarities
are
+ not specified, embedded synchronisation may be required, where supported.
+- data-active: similar to HSYNC and VSYNC specifies data line polarity.
+- field-even-active: field signal level during the even field data
transmission.
+- pclk-sample: rising (1) or falling (0) edge to sample the pixel clock
pin.
+- data-lanes: array of serial, e.g. MIPI CSI-2, data hardware lane numbers
in
+ the ascending order, beginning with logical lane 0.
+- clock-lanes: hardware lane number, used for the clock lane.
+- clock-noncontinuous: a boolean property to allow MIPI CSI-2
non-continuous
+ clock mode.
+
+Example:
+
+ ceu0: ceu@0xfe91 {
+ compatible = renesas,sh-mobile-ceu;
+ reg = 0xfe91 0xa0;
+ interrupts = 0x880;
+
+ mclk: master_clock {
+ compatible = renesas,ceu-clock;
+ #clock-cells = 1;
+ clock-frequency = 5000; /* max clock frequency
*/
+ clock-output-names = mclk;
+ };
+
+ port {
+ #address-cells = 1;
+ #size-cells = 0;
+
+ ceu0_1: link@1 {
+ reg = 1; /* local link # */
+ remote = ov772x_1_1; /* remote phandle */
+ bus-width = 8;/* used data lines */
+ data-shift = 0; /* lines 7:0 are used */
+
+ /* If [hv]sync-active are missing, embedded
bt.605 sync is used */
+ hsync-active = 1; /* active high */
+ vsync-active = 1; /* active high */
+ data-active = 1; /* active high */
+ pclk-sample = 1; /* rising */
+ };
+
+ ceu0_0: link@0 {
+ reg = 0;
+ remote = csi2_2;
+ immutable;
+ };
+ };
+ };
+
+ i2c0: i2c@0xfff2 {
+ ...
+ ov772x_1: camera@0x21 {
+ compatible = omnivision,ov772x;
+ reg = 0x21;
+
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On Fri, Oct 05, 2012 at 05:41:00PM +0200, Guennadi Liakhovetski wrote:
Hi Sascha
+
+ ceu0: ceu@0xfe91 {
+ compatible = renesas,sh-mobile-ceu;
+ reg = 0xfe91 0xa0;
+ interrupts = 0x880;
+
+ mclk: master_clock {
+ compatible = renesas,ceu-clock;
+ #clock-cells = 1;
+ clock-frequency = 5000; /* max clock frequency
*/
+ clock-output-names = mclk;
+ };
+
+ port {
+ #address-cells = 1;
+ #size-cells = 0;
+
+ ceu0_1: link@1 {
+ reg = 1; /* local link # */
+ remote = ov772x_1_1; /* remote phandle */
+ bus-width = 8;/* used data lines */
+ data-shift = 0; /* lines 7:0 are used */
+
+ /* If [hv]sync-active are missing, embedded
bt.605 sync is used */
+ hsync-active = 1; /* active high */
+ vsync-active = 1; /* active high */
+ data-active = 1; /* active high */
+ pclk-sample = 1; /* rising */
+ };
+
+ ceu0_0: link@0 {
+ reg = 0;
+ remote = csi2_2;
+ immutable;
+ };
+ };
+ };
+
+ i2c0: i2c@0xfff2 {
+ ...
+ ov772x_1: camera@0x21 {
+ compatible = omnivision,ov772x;
+ reg = 0x21;
+ vddio-supply = regulator1;
+ vddcore-supply = regulator2;
+
+ clock-frequency = 2000;
+ clocks = mclk 0;
+ clock-names = xclk;
+
+ port {
+ /* With 1 link per port no need in addresses */
+ ov772x_1_1: link {
+ bus-width = 8;
+ remote = ceu0_1;
+ hsync-active = 1;
+ vsync-active = 0; /* who came up
with an inverter here?... */
+ data-active = 1;
+ pclk-sample = 1;
+ };
I currently do not understand why these properties are both in the sensor
and in the link. What happens if they conflict? Are inverters assumed
like suggested above? I think the bus can only have a single bus-width,
why allow multiple bus widths here?
Yes, these nodes represent port configuration of each party on a certain
link. And they can differ in certain properties, like - as you correctly
notice - in the case, when there's an inverter on a line. As for other
properties, some of them must be identical, like bus-width, still, they
have to be provided on both ends, because generally drivers have to be
able to perform all the required configuration based only on the
information from their own nodes, without looking at remote partner node
properties.
So the port associated to the ov772x_1 only describes how to configure
the ov772x and it's up to me to make sure that this configuration
matches the partner device. If I don't then it won't work but soc-camera
will happily continue.
Ok, that's good, I thought there would be some kind of matching
mechanism take place here. It may be worth to make this more explicit in
the docs.
+ reg = 0xffc9 0x1000;
+ interrupts = 0x17a0;
+ #address-cells = 1;
+ #size-cells = 0;
+
+ port@1 {
+ compatible = renesas,csi2c; /* one of CSI2I and
CSI2C */
+ reg = 1; /* CSI-2 PHY #1 of 2:
PHY_S, PHY_M has port address 0, is unused */
+
+ csi2_1: link {
+ clock-lanes = 0;
+ data-lanes = 2, 1;
+ remote = imx074_1;
+ };
+ };
+ port@2 {
+ reg = 2; /* port 2: link to the
CEU */
+
+ csi2_2: link {
+ immutable;
+ remote = ceu0_0;
+ };
+ };
Maybe the example would be clearer if you split it up in two, one simple
case with the csi2_1 - imx074_1 and a more advanced with the link in
between.
With no link between two ports no connection is possible, so, only
examples with links make sense.
I should have said with the renesas,sh-mobile-ceu in between.
So simple example: csi2_1 -l- imx074_1
advanced: csi2_2 -l- ceu -l- ov772x
It took me some
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On 10/02/2012 09:33 AM, Guennadi Liakhovetski wrote:
Hi Rob
On Tue, 2 Oct 2012, Rob Herring wrote:
On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
Co-authored-by: Sylwester Nawrocki s.nawro...@samsung.com
Signed-off-by: Guennadi Liakhovetski g.liakhovet...@gmx.de
---
Documentation/devicetree/bindings/media/v4l2.txt | 162
++
1 files changed, 162 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/v4l2.txt
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
new file mode 100644
index 000..b8b3f41
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/v4l2.txt
@@ -0,0 +1,162 @@
+Video4Linux Version 2 (V4L2)
DT describes the h/w, but V4L2 is Linux specific. I think the binding
looks pretty good in terms of it is describing the h/w and not V4L2
components or settings. So in this case it's really just the name of the
file and title I have issue with.
Hm, I see your point, then, I guess, you'd also like the file name
changed. What should we use then? Just video? But there's already a
whole directory Documentation/devicetree/bindings/video dedicated to
graphics output (drm, fbdev). video-camera or video-capture? But this
file shall also be describing video output. Use video.txt and describe
inside what exactly this file is for?
Video output will probably have a lot of overlap with the graphics side.
How about video-interfaces.txt?
One other comment below:
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors,
controlled
+over an I2C, SPI or UART bus, and SoC internal IP blocks, including video
DMA
+engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to other
SoC
+blocks. External devices are represented as child nodes of their
respective bus
+controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT
nodes.
+Configuration of a port depends on other devices participating in the data
+transfer and is described by link DT nodes, specified as children of the
+port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on the
same
+bus, a link child DT node must be provided for each of them. If more
than one
+port is present on a device or more than one link is connected to a port, a
+common scheme, using #address-cells, #size-cells and reg properties
is
+used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
This name is a little vague. Perhaps endpoint would be better.
endpoint can also refer to something local like in USB case. Maybe
rather the description of the remote property should be improved?
remote-endpoint?
Thanks
Guennadi
Rob
+- slave-mode: a boolean property, run the link in slave mode. Default is
master
+ mode.
+- data-shift: on parallel data busses, if data-width is used to specify the
+ number of data lines, data-shift can be used to specify which data lines
are
+ used, e.g. data-width=10; data-shift=2; means, that lines 9:2 are
used.
+- hsync-active: 1 or 0 for active-high or -low HSYNC signal polarity
+ respectively.
+- vsync-active: ditto for VSYNC. Note, that if HSYNC and VSYNC polarities
are
+ not specified, embedded synchronisation may be required, where supported.
+- data-active: similar to HSYNC and VSYNC specifies data line polarity.
+- field-even-active: field signal level during the even field data
transmission.
+- pclk-sample: rising (1) or falling (0) edge to sample the pixel clock
pin.
+- data-lanes: array of serial, e.g. MIPI CSI-2, data hardware lane numbers
in
+ the ascending order, beginning with logical lane 0.
+- clock-lanes: hardware lane number, used for the clock lane.
+- clock-noncontinuous: a boolean property to allow MIPI CSI-2
non-continuous
+ clock mode.
+
+Example:
+
+ ceu0: ceu@0xfe91 {
+ compatible = renesas,sh-mobile-ceu;
+ reg = 0xfe91 0xa0;
+ interrupts = 0x880;
+
+ mclk: master_clock {
+ compatible = renesas,ceu-clock;
+ #clock-cells = 1;
+ clock-frequency = 5000; /* max clock frequency
*/
+ clock-output-names = mclk;
+ };
+
+ port {
+ #address-cells = 1;
+ #size-cells = 0;
+
+ ceu0_1: link@1 {
+ reg = 1; /* local link # */
+ remote = ov772x_1_1; /* remote phandle */
+ bus-width = 8;/*
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
Co-authored-by: Sylwester Nawrocki s.nawro...@samsung.com
Signed-off-by: Guennadi Liakhovetski g.liakhovet...@gmx.de
---
Documentation/devicetree/bindings/media/v4l2.txt | 162
++
1 files changed, 162 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/v4l2.txt
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
new file mode 100644
index 000..b8b3f41
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/v4l2.txt
@@ -0,0 +1,162 @@
+Video4Linux Version 2 (V4L2)
DT describes the h/w, but V4L2 is Linux specific. I think the binding
looks pretty good in terms of it is describing the h/w and not V4L2
components or settings. So in this case it's really just the name of the
file and title I have issue with.
One other comment below:
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors, controlled
+over an I2C, SPI or UART bus, and SoC internal IP blocks, including video DMA
+engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to other SoC
+blocks. External devices are represented as child nodes of their respective
bus
+controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT nodes.
+Configuration of a port depends on other devices participating in the data
+transfer and is described by link DT nodes, specified as children of the
+port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on the
same
+bus, a link child DT node must be provided for each of them. If more than
one
+port is present on a device or more than one link is connected to a port, a
+common scheme, using #address-cells, #size-cells and reg properties is
+used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
This name is a little vague. Perhaps endpoint would be better.
Rob
+- slave-mode: a boolean property, run the link in slave mode. Default is
master
+ mode.
+- data-shift: on parallel data busses, if data-width is used to specify the
+ number of data lines, data-shift can be used to specify which data lines
are
+ used, e.g. data-width=10; data-shift=2; means, that lines 9:2 are
used.
+- hsync-active: 1 or 0 for active-high or -low HSYNC signal polarity
+ respectively.
+- vsync-active: ditto for VSYNC. Note, that if HSYNC and VSYNC polarities are
+ not specified, embedded synchronisation may be required, where supported.
+- data-active: similar to HSYNC and VSYNC specifies data line polarity.
+- field-even-active: field signal level during the even field data
transmission.
+- pclk-sample: rising (1) or falling (0) edge to sample the pixel clock pin.
+- data-lanes: array of serial, e.g. MIPI CSI-2, data hardware lane numbers in
+ the ascending order, beginning with logical lane 0.
+- clock-lanes: hardware lane number, used for the clock lane.
+- clock-noncontinuous: a boolean property to allow MIPI CSI-2 non-continuous
+ clock mode.
+
+Example:
+
+ ceu0: ceu@0xfe91 {
+ compatible = renesas,sh-mobile-ceu;
+ reg = 0xfe91 0xa0;
+ interrupts = 0x880;
+
+ mclk: master_clock {
+ compatible = renesas,ceu-clock;
+ #clock-cells = 1;
+ clock-frequency = 5000; /* max clock frequency
*/
+ clock-output-names = mclk;
+ };
+
+ port {
+ #address-cells = 1;
+ #size-cells = 0;
+
+ ceu0_1: link@1 {
+ reg = 1; /* local link # */
+ remote = ov772x_1_1; /* remote phandle */
+ bus-width = 8;/* used data lines */
+ data-shift = 0; /* lines 7:0 are used */
+
+ /* If [hv]sync-active are missing, embedded
bt.605 sync is used */
+ hsync-active = 1; /* active high */
+ vsync-active = 1; /* active high */
+ data-active = 1; /* active high */
+ pclk-sample = 1; /* rising */
+ };
+
+ ceu0_0: link@0 {
+ reg = 0;
+ remote = csi2_2;
+ immutable;
+ };
+ };
+ };
+
+ i2c0: i2c@0xfff2 {
+
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
Hi Rob
On Tue, 2 Oct 2012, Rob Herring wrote:
On 09/27/2012 09:07 AM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
Co-authored-by: Sylwester Nawrocki s.nawro...@samsung.com
Signed-off-by: Guennadi Liakhovetski g.liakhovet...@gmx.de
---
Documentation/devicetree/bindings/media/v4l2.txt | 162
++
1 files changed, 162 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/v4l2.txt
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
new file mode 100644
index 000..b8b3f41
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/v4l2.txt
@@ -0,0 +1,162 @@
+Video4Linux Version 2 (V4L2)
DT describes the h/w, but V4L2 is Linux specific. I think the binding
looks pretty good in terms of it is describing the h/w and not V4L2
components or settings. So in this case it's really just the name of the
file and title I have issue with.
Hm, I see your point, then, I guess, you'd also like the file name
changed. What should we use then? Just video? But there's already a
whole directory Documentation/devicetree/bindings/video dedicated to
graphics output (drm, fbdev). video-camera or video-capture? But this
file shall also be describing video output. Use video.txt and describe
inside what exactly this file is for?
One other comment below:
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors,
controlled
+over an I2C, SPI or UART bus, and SoC internal IP blocks, including video
DMA
+engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to other
SoC
+blocks. External devices are represented as child nodes of their
respective bus
+controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT
nodes.
+Configuration of a port depends on other devices participating in the data
+transfer and is described by link DT nodes, specified as children of the
+port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on the
same
+bus, a link child DT node must be provided for each of them. If more
than one
+port is present on a device or more than one link is connected to a port, a
+common scheme, using #address-cells, #size-cells and reg properties
is
+used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
This name is a little vague. Perhaps endpoint would be better.
endpoint can also refer to something local like in USB case. Maybe
rather the description of the remote property should be improved?
Thanks
Guennadi
Rob
+- slave-mode: a boolean property, run the link in slave mode. Default is
master
+ mode.
+- data-shift: on parallel data busses, if data-width is used to specify the
+ number of data lines, data-shift can be used to specify which data lines
are
+ used, e.g. data-width=10; data-shift=2; means, that lines 9:2 are
used.
+- hsync-active: 1 or 0 for active-high or -low HSYNC signal polarity
+ respectively.
+- vsync-active: ditto for VSYNC. Note, that if HSYNC and VSYNC polarities
are
+ not specified, embedded synchronisation may be required, where supported.
+- data-active: similar to HSYNC and VSYNC specifies data line polarity.
+- field-even-active: field signal level during the even field data
transmission.
+- pclk-sample: rising (1) or falling (0) edge to sample the pixel clock
pin.
+- data-lanes: array of serial, e.g. MIPI CSI-2, data hardware lane numbers
in
+ the ascending order, beginning with logical lane 0.
+- clock-lanes: hardware lane number, used for the clock lane.
+- clock-noncontinuous: a boolean property to allow MIPI CSI-2
non-continuous
+ clock mode.
+
+Example:
+
+ ceu0: ceu@0xfe91 {
+ compatible = renesas,sh-mobile-ceu;
+ reg = 0xfe91 0xa0;
+ interrupts = 0x880;
+
+ mclk: master_clock {
+ compatible = renesas,ceu-clock;
+ #clock-cells = 1;
+ clock-frequency = 5000; /* max clock frequency
*/
+ clock-output-names = mclk;
+ };
+
+ port {
+ #address-cells = 1;
+ #size-cells = 0;
+
+ ceu0_1: link@1 {
+ reg = 1; /* local link # */
+ remote = ov772x_1_1; /* remote phandle */
+ bus-width = 8;/* used data lines */
+ data-shift = 0; /* lines
Re: [PATCH 04/14] media: add V4L2 DT binding documentation
Hi Guennadi,
On 09/27/2012 04:07 PM, Guennadi Liakhovetski wrote:
This patch adds a document, describing common V4L2 device tree bindings.
Co-authored-by: Sylwester Nawrockis.nawro...@samsung.com
Signed-off-by: Guennadi Liakhovetskig.liakhovet...@gmx.de
---
Documentation/devicetree/bindings/media/v4l2.txt | 162
++
1 files changed, 162 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/v4l2.txt
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
new file mode 100644
index 000..b8b3f41
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/v4l2.txt
@@ -0,0 +1,162 @@
+Video4Linux Version 2 (V4L2)
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors, controlled
+over an I2C, SPI or UART bus, and SoC internal IP blocks, including video DMA
+engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to other SoC
+blocks. External devices are represented as child nodes of their respective
bus
+controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT nodes.
+Configuration of a port depends on other devices participating in the data
+transfer and is described by link DT nodes, specified as children of the
+port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on the
same
+bus, a link child DT node must be provided for each of them. If more than
one
+port is present on a device or more than one link is connected to a port, a
+common scheme, using #address-cells, #size-cells and reg properties is
+used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
+- slave-mode: a boolean property, run the link in slave mode. Default is
master
+ mode.
+- data-shift: on parallel data busses, if data-width is used to specify the
+ number of data lines, data-shift can be used to specify which data lines
are
+ used, e.g. data-width=10; data-shift=2; means, that lines 9:2 are
used.
+- hsync-active: 1 or 0 for active-high or -low HSYNC signal polarity
+ respectively.
+- vsync-active: ditto for VSYNC. Note, that if HSYNC and VSYNC polarities are
+ not specified, embedded synchronisation may be required, where supported.
+- data-active: similar to HSYNC and VSYNC specifies data line polarity.
+- field-even-active: field signal level during the even field data
transmission.
+- pclk-sample: rising (1) or falling (0) edge to sample the pixel clock pin.
+- data-lanes: array of serial, e.g. MIPI CSI-2, data hardware lane numbers in
+ the ascending order, beginning with logical lane 0.
+- clock-lanes: hardware lane number, used for the clock lane.
It is not very clear we are using common contiguous range of logical indexes
for the clock and the data lanes, IMO. Maybe something like this would be
more explicit:
- data-lanes: an array of hardware data lane indexes. Position of an entry
determines logical lane number, while the value of an entry indicates hardware
lane number, e.g. for 2-lane MIPI CSI-2 bus we could have data-lanes = 1,
2;,
assuming the clock lane is on hardware lane 0. This property is applicable to
serial buses only (e.g. MIPI CSI-2).
?
--
Thanks,
Sylwester
--
To unsubscribe from this list: send the line unsubscribe linux-media in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH 04/14] media: add V4L2 DT binding documentation
This patch adds a document, describing common V4L2 device tree bindings.
Co-authored-by: Sylwester Nawrocki s.nawro...@samsung.com
Signed-off-by: Guennadi Liakhovetski g.liakhovet...@gmx.de
---
Documentation/devicetree/bindings/media/v4l2.txt | 162 ++
1 files changed, 162 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/media/v4l2.txt
diff --git a/Documentation/devicetree/bindings/media/v4l2.txt
b/Documentation/devicetree/bindings/media/v4l2.txt
new file mode 100644
index 000..b8b3f41
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/v4l2.txt
@@ -0,0 +1,162 @@
+Video4Linux Version 2 (V4L2)
+
+General concept
+---
+
+Video pipelines consist of external devices, e.g. camera sensors, controlled
+over an I2C, SPI or UART bus, and SoC internal IP blocks, including video DMA
+engines and video data processors.
+
+SoC internal blocks are described by DT nodes, placed similarly to other SoC
+blocks. External devices are represented as child nodes of their respective bus
+controller nodes, e.g. I2C.
+
+Data interfaces on all video devices are described by port child DT nodes.
+Configuration of a port depends on other devices participating in the data
+transfer and is described by link DT nodes, specified as children of the
+port nodes:
+
+/foo {
+ port@0 {
+ link@0 { ... };
+ link@1 { ... };
+ };
+ port@1 { ... };
+};
+
+If a port can be configured to work with more than one other device on the same
+bus, a link child DT node must be provided for each of them. If more than one
+port is present on a device or more than one link is connected to a port, a
+common scheme, using #address-cells, #size-cells and reg properties is
+used.
+
+Optional link properties:
+- remote: phandle to the other endpoint link DT node.
+- slave-mode: a boolean property, run the link in slave mode. Default is master
+ mode.
+- data-shift: on parallel data busses, if data-width is used to specify the
+ number of data lines, data-shift can be used to specify which data lines are
+ used, e.g. data-width=10; data-shift=2; means, that lines 9:2 are used.
+- hsync-active: 1 or 0 for active-high or -low HSYNC signal polarity
+ respectively.
+- vsync-active: ditto for VSYNC. Note, that if HSYNC and VSYNC polarities are
+ not specified, embedded synchronisation may be required, where supported.
+- data-active: similar to HSYNC and VSYNC specifies data line polarity.
+- field-even-active: field signal level during the even field data
transmission.
+- pclk-sample: rising (1) or falling (0) edge to sample the pixel clock pin.
+- data-lanes: array of serial, e.g. MIPI CSI-2, data hardware lane numbers in
+ the ascending order, beginning with logical lane 0.
+- clock-lanes: hardware lane number, used for the clock lane.
+- clock-noncontinuous: a boolean property to allow MIPI CSI-2 non-continuous
+ clock mode.
+
+Example:
+
+ ceu0: ceu@0xfe91 {
+ compatible = renesas,sh-mobile-ceu;
+ reg = 0xfe91 0xa0;
+ interrupts = 0x880;
+
+ mclk: master_clock {
+ compatible = renesas,ceu-clock;
+ #clock-cells = 1;
+ clock-frequency = 5000; /* max clock frequency
*/
+ clock-output-names = mclk;
+ };
+
+ port {
+ #address-cells = 1;
+ #size-cells = 0;
+
+ ceu0_1: link@1 {
+ reg = 1; /* local link # */
+ remote = ov772x_1_1; /* remote phandle */
+ bus-width = 8;/* used data lines */
+ data-shift = 0; /* lines 7:0 are used */
+
+ /* If [hv]sync-active are missing, embedded
bt.605 sync is used */
+ hsync-active = 1; /* active high */
+ vsync-active = 1; /* active high */
+ data-active = 1; /* active high */
+ pclk-sample = 1; /* rising */
+ };
+
+ ceu0_0: link@0 {
+ reg = 0;
+ remote = csi2_2;
+ immutable;
+ };
+ };
+ };
+
+ i2c0: i2c@0xfff2 {
+ ...
+ ov772x_1: camera@0x21 {
+ compatible = omnivision,ov772x;
+ reg = 0x21;
+ vddio-supply = regulator1;
+ vddcore-supply = regulator2;
+
+ clock-frequency = 2000;
+ clocks = mclk 0;
+ clock-names = xclk;
+
+ port {
+
