diff mbox series

[v4,4/6] dt-bindings: phy: Document the Synopsys MIPI DPHY Rx bindings

Message ID 1560280855-18085-5-git-send-email-luis.oliveira@synopsys.com (mailing list archive)
State New, archived
Headers show
Series platform: dwc: Adding DesignWare MIPI CSI-2 Host and D-PHY | expand

Commit Message

Luis de Oliveira June 11, 2019, 7:20 p.m. UTC 
Add device-tree bindings documentation for SNPS DesignWare MIPI D-PHY in
RX mode.

Signed-off-by: Luis Oliveira <luis.oliveira@synopsys.com>
---
Changelog
v3-v4
- @Laurent I know I told you I could remove the snps,dphy-frequency on V3 but
  it is really useful for me here. I removed all other the proprietary
  properties except this one. Do you still think it must be removed?
- Frequency units @Rob

 .../devicetree/bindings/phy/snps,dw-dphy-rx.txt    | 29 ++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt

Comments

Rob Herring July 9, 2019, 2:20 p.m. UTC | #1 
On Tue, Jun 11, 2019 at 09:20:53PM +0200, Luis Oliveira wrote:
> Add device-tree bindings documentation for SNPS DesignWare MIPI D-PHY in
> RX mode.
> 
> Signed-off-by: Luis Oliveira <luis.oliveira@synopsys.com>
> ---
> Changelog
> v3-v4
> - @Laurent I know I told you I could remove the snps,dphy-frequency on V3 but
>   it is really useful for me here. I removed all other the proprietary
>   properties except this one. Do you still think it must be removed?
> - Frequency units @Rob

Frequency units means append '-khz' to the property name. That also 
makes the 'frequency' part redundant, so maybe name it more around what 
the frequency is. The frequency for what?

Rob

> 
>  .../devicetree/bindings/phy/snps,dw-dphy-rx.txt    | 29 ++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
> 
> diff --git a/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt b/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
> new file mode 100644
> index 0000000..50603e6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
> @@ -0,0 +1,29 @@
> +Synopsys DesignWare MIPI Rx D-PHY block details
> +
> +Description
> +-----------
> +
> +The Synopsys MIPI D-PHY controller supports MIPI-DPHY in receiver mode.
> +Please refer to phy-bindings.txt for more information.
> +
> +Required properties:
> +- compatible		: Shall be "snps,dw-dphy-rx".
> +- #phy-cells		: Must be 1.
> +- bus-width		: Size of the test interface data bus (8 bits->8 or
> +			  12bits->12).
> +- snps,dphy-frequency	: Frequency at which D-PHY should start, configurable.
> +			  Check Synopsys databook. (-kHz)
> +- reg			: Test interface register. This correspondes to the
> +			  physical base address of the controller and size of
> +			  the device memory mapped registers; Check Synopsys
> +			  databook.
> +
> +Example:
> +
> +	mipi_dphy_rx1: dphy@d00003040 {
> +		compatible = "snps,dw-dphy-rx";
> +		#phy-cells = <1>;
> +		bus-width = <12>;
> +		snps,dphy-frequency = <300000>;
> +		reg = <0xd0003040 0x20>;
> +	};
> -- 
> 2.7.4
>
Luis de Oliveira July 9, 2019, 4:28 p.m. UTC | #2 
From: Rob Herring <robh@kernel.org>
Date: Tue, Jul 09, 2019 at 15:20:00

> On Tue, Jun 11, 2019 at 09:20:53PM +0200, Luis Oliveira wrote:
> > Add device-tree bindings documentation for SNPS DesignWare MIPI D-PHY in
> > RX mode.
> > 
> > Signed-off-by: Luis Oliveira <luis.oliveira@synopsys.com>
> > ---
> > Changelog
> > v3-v4
> > - @Laurent I know I told you I could remove the snps,dphy-frequency on V3 but
> >   it is really useful for me here. I removed all other the proprietary
> >   properties except this one. Do you still think it must be removed?
> > - Frequency units @Rob
> 
> Frequency units means append '-khz' to the property name. That also 
> makes the 'frequency' part redundant, so maybe name it more around what 
> the frequency is. The frequency for what?
> 
> Rob
> 

This is the D-PHY high speed frequency configuration that corresponds to 
the high speed data transfer of the bus.
Basically is the transmission speed per lane.
Do you think I can use "link-frequencies" (present in 
video-interfaces.txt) with one frequency?


> > 
> >  .../devicetree/bindings/phy/snps,dw-dphy-rx.txt    | 29 ++++++++++++++++++++++
> >  1 file changed, 29 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt b/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
> > new file mode 100644
> > index 0000000..50603e6
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
> > @@ -0,0 +1,29 @@
> > +Synopsys DesignWare MIPI Rx D-PHY block details
> > +
> > +Description
> > +-----------
> > +
> > +The Synopsys MIPI D-PHY controller supports MIPI-DPHY in receiver mode.
> > +Please refer to phy-bindings.txt for more information.
> > +
> > +Required properties:
> > +- compatible		: Shall be "snps,dw-dphy-rx".
> > +- #phy-cells		: Must be 1.
> > +- bus-width		: Size of the test interface data bus (8 bits->8 or
> > +			  12bits->12).
> > +- snps,dphy-frequency	: Frequency at which D-PHY should start, configurable.
> > +			  Check Synopsys databook. (-kHz)
> > +- reg			: Test interface register. This correspondes to the
> > +			  physical base address of the controller and size of
> > +			  the device memory mapped registers; Check Synopsys
> > +			  databook.
> > +
> > +Example:
> > +
> > +	mipi_dphy_rx1: dphy@d00003040 {
> > +		compatible = "snps,dw-dphy-rx";
> > +		#phy-cells = <1>;
> > +		bus-width = <12>;
> > +		snps,dphy-frequency = <300000>;
> > +		reg = <0xd0003040 0x20>;
> > +	};
> > -- 
> > 2.7.4
> > 

Thank you Rob,
Luis
Rob Herring July 10, 2019, 1:50 p.m. UTC | #3 
On Tue, Jul 9, 2019 at 10:29 AM Luis de Oliveira
<Luis.Oliveira@synopsys.com> wrote:
>
> From: Rob Herring <robh@kernel.org>
> Date: Tue, Jul 09, 2019 at 15:20:00
>
> > On Tue, Jun 11, 2019 at 09:20:53PM +0200, Luis Oliveira wrote:
> > > Add device-tree bindings documentation for SNPS DesignWare MIPI D-PHY in
> > > RX mode.
> > >
> > > Signed-off-by: Luis Oliveira <luis.oliveira@synopsys.com>
> > > ---
> > > Changelog
> > > v3-v4
> > > - @Laurent I know I told you I could remove the snps,dphy-frequency on V3 but
> > >   it is really useful for me here. I removed all other the proprietary
> > >   properties except this one. Do you still think it must be removed?
> > > - Frequency units @Rob
> >
> > Frequency units means append '-khz' to the property name. That also
> > makes the 'frequency' part redundant, so maybe name it more around what
> > the frequency is. The frequency for what?
> >
> > Rob
> >
>
> This is the D-PHY high speed frequency configuration that corresponds to
> the high speed data transfer of the bus.
> Basically is the transmission speed per lane.
> Do you think I can use "link-frequencies" (present in
> video-interfaces.txt) with one frequency?

Seems reasonable.

Rob
Sakari Ailus Aug. 9, 2019, 2:42 p.m. UTC | #4 
Hi Luis,

On Tue, Jun 11, 2019 at 09:20:53PM +0200, Luis Oliveira wrote:
> Add device-tree bindings documentation for SNPS DesignWare MIPI D-PHY in
> RX mode.
> 
> Signed-off-by: Luis Oliveira <luis.oliveira@synopsys.com>
> ---
> Changelog
> v3-v4
> - @Laurent I know I told you I could remove the snps,dphy-frequency on V3 but
>   it is really useful for me here. I removed all other the proprietary
>   properties except this one. Do you still think it must be removed?

Yes. DT is the wrong place for runtime configuration. You get that
information using the V4L2_CID_LINK_FREQ control on the upstream
sub-device.

> - Frequency units @Rob
> 
>  .../devicetree/bindings/phy/snps,dw-dphy-rx.txt    | 29 ++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
> 
> diff --git a/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt b/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
> new file mode 100644
> index 0000000..50603e6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
> @@ -0,0 +1,29 @@
> +Synopsys DesignWare MIPI Rx D-PHY block details
> +
> +Description
> +-----------
> +
> +The Synopsys MIPI D-PHY controller supports MIPI-DPHY in receiver mode.
> +Please refer to phy-bindings.txt for more information.
> +
> +Required properties:
> +- compatible		: Shall be "snps,dw-dphy-rx".
> +- #phy-cells		: Must be 1.
> +- bus-width		: Size of the test interface data bus (8 bits->8 or
> +			  12bits->12).

Hmm. This seems like runtime configuration as well.

> +- snps,dphy-frequency	: Frequency at which D-PHY should start, configurable.
> +			  Check Synopsys databook. (-kHz)
> +- reg			: Test interface register. This correspondes to the
> +			  physical base address of the controller and size of
> +			  the device memory mapped registers; Check Synopsys
> +			  databook.

Is this just for testing purposes or not?

> +
> +Example:
> +
> +	mipi_dphy_rx1: dphy@d00003040 {
> +		compatible = "snps,dw-dphy-rx";
> +		#phy-cells = <1>;
> +		bus-width = <12>;
> +		snps,dphy-frequency = <300000>;
> +		reg = <0xd0003040 0x20>;
> +	};
Sakari Ailus Aug. 9, 2019, 2:45 p.m. UTC | #5 
On Fri, Aug 09, 2019 at 05:42:52PM +0300, Sakari Ailus wrote:
> Hi Luis,
> 
> On Tue, Jun 11, 2019 at 09:20:53PM +0200, Luis Oliveira wrote:
> > Add device-tree bindings documentation for SNPS DesignWare MIPI D-PHY in
> > RX mode.
> > 
> > Signed-off-by: Luis Oliveira <luis.oliveira@synopsys.com>
> > ---
> > Changelog
> > v3-v4
> > - @Laurent I know I told you I could remove the snps,dphy-frequency on V3 but
> >   it is really useful for me here. I removed all other the proprietary
> >   properties except this one. Do you still think it must be removed?
> 
> Yes. DT is the wrong place for runtime configuration. You get that
> information using the V4L2_CID_LINK_FREQ control on the upstream
> sub-device.

And the PHY driver itself gets that in its configuration (struct
phy_configure_opts_mipi_dphy through the configure op).
Sakari Ailus Aug. 9, 2019, 2:47 p.m. UTC | #6 
On Fri, Aug 09, 2019 at 05:42:52PM +0300, Sakari Ailus wrote:
> > +The Synopsys MIPI D-PHY controller supports MIPI-DPHY in receiver mode.
> > +Please refer to phy-bindings.txt for more information.
> > +
> > +Required properties:
> > +- compatible		: Shall be "snps,dw-dphy-rx".
> > +- #phy-cells		: Must be 1.
> > +- bus-width		: Size of the test interface data bus (8 bits->8 or
> > +			  12bits->12).
> 
> Hmm. This seems like runtime configuration as well.

And it's for the parallel busses.

I'd like to see the bindings that have the other interface described as
well if there are parameters that affect device configuration there.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt b/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
new file mode 100644
index 0000000..50603e6
--- /dev/null
+++ b/Documentation/devicetree/bindings/phy/snps,dw-dphy-rx.txt
@@ -0,0 +1,29 @@ 
+Synopsys DesignWare MIPI Rx D-PHY block details
+
+Description
+-----------
+
+The Synopsys MIPI D-PHY controller supports MIPI-DPHY in receiver mode.
+Please refer to phy-bindings.txt for more information.
+
+Required properties:
+- compatible		: Shall be "snps,dw-dphy-rx".
+- #phy-cells		: Must be 1.
+- bus-width		: Size of the test interface data bus (8 bits->8 or
+			  12bits->12).
+- snps,dphy-frequency	: Frequency at which D-PHY should start, configurable.
+			  Check Synopsys databook. (-kHz)
+- reg			: Test interface register. This correspondes to the
+			  physical base address of the controller and size of
+			  the device memory mapped registers; Check Synopsys
+			  databook.
+
+Example:
+
+	mipi_dphy_rx1: dphy@d00003040 {
+		compatible = "snps,dw-dphy-rx";
+		#phy-cells = <1>;
+		bus-width = <12>;
+		snps,dphy-frequency = <300000>;
+		reg = <0xd0003040 0x20>;
+	};