Re: [PATCH v4 06/12] media: dt-bindings: add bindings for i.MX7 media driver

Hi Sakari,
Thanks for the review.
On Fri 18 May 2018 at 06:58, Sakari Ailus wrote:

Hi Rui,

On Thu, May 17, 2018 at 01:50:27PM +0100, Rui Miguel Silva 
wrote:

quoted

Add bindings documentation for i.MX7 media drivers.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
---
 .../devicetree/bindings/media/imx7.txt        | 145 
 ++++++++++++++++++
 1 file changed, 145 insertions(+)
 create mode 100644 
 Documentation/devicetree/bindings/media/imx7.txt

diff --git a/Documentation/devicetree/bindings/media/imx7.txt 

b/Documentation/devicetree/bindings/media/imx7.txt
new file mode 100644
index 000000000000..161cff8e6442

--- /dev/null
+++ b/Documentation/devicetree/bindings/media/imx7.txt

@@ -0,0 +1,145 @@
+Freescale i.MX7 Media Video Device
+==================================
+
+Video Media Controller node
+---------------------------

Note that DT bindings document the hardware, they are as such 
not Linux
dependent.

This was removed in this series, however I removed it in the wrong 
patch,
If you see patch 11/12 you will see this being removed. I will fix 
this
in v5. Thanks for notice it.

quoted

+
+This is the media controller node for video capture support. 
It is a
+virtual device that lists the camera serial interface nodes 
that the
+media device will control.

Ditto.

quoted

+
+Required properties:
+- compatible : "fsl,imx7-capture-subsystem";
+- ports      : Should contain a list of phandles pointing to 
camera
+		sensor interface port of CSI
+
+example:
+
+capture-subsystem {

What's the purpose of this node, if you only refer to another 
device? This
one rather does not look like a real device at all.

quoted

+	compatible = "fsl,imx7-capture-subsystem";
+	ports = <&csi>;
+};
+
+
+mipi_csi2 node
+--------------
+
+This is the device node for the MIPI CSI-2 receiver core in 
i.MX7 SoC. It is
+compatible with previous version of Samsung D-phy.
+
+Required properties:
+
+- compatible    : "fsl,imx7-mipi-csi2";
+- reg           : base address and length of the register set 
for the device;
+- interrupts    : should contain MIPI CSIS interrupt;
+- clocks        : list of clock specifiers, see
+ 
Documentation/devicetree/bindings/clock/clock-bindings.txt for 
details;
+- clock-names   : must contain "pclk", "wrap" and "phy" 
entries, matching
+                  entries in the clock property;
+- power-domains : a phandle to the power domain, see
+ 
Documentation/devicetree/bindings/power/power_domain.txt for 
details.
+- reset-names   : should include following entry "mrst";
+- resets        : a list of phandle, should contain reset 
entry of
+                  reset-names;
+- phy-supply    : from the generic phy bindings, a phandle to 
a regulator that
+	          provides power to MIPI CSIS core;
+- bus-width     : maximum number of data lanes supported (SoC 
specific);
+
+Optional properties:
+
+- clock-frequency : The IP's main (system bus) clock frequency 
in Hz, default
+		    value when this property is not specified is 
166 MHz;
+
+port node
+---------
+
+- reg		  : (required) can take the values 0 or 1, 
where 0 is the
+                     related sink port and port 1 should be 
the source one;
+
+endpoint node
+-------------
+
+- data-lanes    : (required) an array specifying active 
physical MIPI-CSI2
+		    data input lanes and their mapping to logical 
lanes; the
+		    array's content is unused, only its length is 
meaningful;
+
+- fsl,csis-hs-settle : (optional) differential receiver 
(HS-RX) settle time;

Could you calculate this, as other drivers do? It probably 
changes
depending on the device runtime configuration.

The only reference to possible values to this parameter is given 
by
table in [0], can you point me out the formula for imx7 in the
documentation?

---
Cheers,
	Rui

[0] https://community.nxp.com/thread/463777