Re: [PATCH RFC V2 1/2] Documentation: add Device tree bindings for QCA7000

Hello Sergei,

Am 02.07.2014 13:51, schrieb Sergei Shtylyov:

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+- qca,legacy-mode : Set the SPI data transfer of the QCA7000 to
legacy mode.
+  In this mode the SPI master must toggle the chip select between
each data
+  word. In burst mode these gaps aren't necessary, which is faster.
+  This setting depends on how the QCA7000 is setup via GPIO pin
strapping.
+  If the property is missing the driver defaults to burst mode.
+
+Example:
+
+/* Freescale i.MX28 SPI master*/
+ssp2: ssp@80014000 {

   The node name should probably be "spi" here.

this working example comes from my test environment and i prefer to keep
it intact.
The strange name "ssp" comes from mxs-spi binding [1]. Unfortunately i
don't have another hardware platform.

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+    #address-cells = <1>;
+    #size-cells = <0>;
+    compatible = "fsl,imx28-spi";
+    pinctrl-names = "default";
+    pinctrl-0 = <&spi2_pins_a>;
+    status = "okay";
+
+    qca7000@0 {

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    According to the ePAPR standard [1]:

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The name of a node should be somewhat generic, reflecting the function
of the device and not its precise programming model. If appropriate,
the name should be one of the following choices:
[...]
  - ethernet;

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I have doubts about that. I agree that the current node name doesn't fit
to ePAPR. The function of a QCA7000 isn't really a ethernet device. Yes,
this linux driver implementation handle the QCA7000 as a ethernet
device. But the QCA7000 a powerline device according to Homeplug
GreenPHY.

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How about using powerline as node name?

   I don't know the differences between Ethernet and PowerLine but
looks like they are minimal as you're implementing an Ethernet driver.
So I'm still for "ethernet".

On physical layer Ethernet and Powerline are totally different, but from
user point of view they behaves similiar. If nobody appeal i will change
it to "ethernet".

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+        compatible = "qca,qca7000";
+        interrupt-parent = <&gpio3>;      /* GPIO Bank 3 */
+        interrupts = <25 0x1>;            /* Index: 25, rising
edge */
+        reg = <0x0>;
+        spi-cpha;                         /* SPI mode: CPHA=1 */
+        spi-cpol;                         /* SPI mode: CPOL=1 */
+        spi-max-frequency = <8000000>;    /* freq: 8 MHz */
+        local-mac-address = [ A0 B0 C0 D0 E0 F0 ];
+    };
+};

Thanks about your comments.

BR Stefan Wahren

[1] -
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/spi/mxs-spi.txt?id=refs/tags/v3.16-rc3