Using bcm2835 with QCA7000

[Stefan Wahren]

Hi,

i'm porting the spi protocol driver [1] for the Qualcomm QCA7000 
Homeplug GreenPHY [2] to linux mainline including devicetree support. My 
current development platform uses a i.MX28, but the goal is that the 
driver works with many other spi masters. Now i want to go the 
combination bcm2835 and QCA7000. Unfortunately it seems to me that most 
of the Raspberry Pi users use a kernel without devicetree support and 
any update to date documentation about that is rare.

So i hope somebody on this list can review my dts patch. If it finally 
works i would add it as another example in the binding documentation.

The pin assignment and spi role of the QCA7000 are identical to the 
Microchip ENC28J60. So we need the following pins: CE0, MISO, MOSI, SCLK 
and GPIO25 as the interrupt pin.

Are these modifications okay?

Any comments about this are very welcome.

Kind regards
Stefan Wahren

[1] - https://github.com/I2SE/qca7000/tree/linux-mainline
[2] - http://www.qca.qualcomm.com/wp-content/uploads/2013/11/QCA7000.pdf
[3] - http://ww1.microchip.com/downloads/en/devicedoc/39662a.pdf

---

diff --git a/arch/arm/boot/dts/bcm2835-rpi-b.dts 
b/arch/arm/boot/dts/bcm2835-rpi-b.dts
index 2a3b1c1..3172d07 100644
--- a/arch/arm/boot/dts/bcm2835-rpi-b.dts
+++ b/arch/arm/boot/dts/bcm2835-rpi-b.dts
@@ -23,15 +23,20 @@

  &gpio {
  	pinctrl-names = "default";
-	pinctrl-0 = <&gpioout &alt0 &alt3>;
+	pinctrl-0 = <&gpioout &gpioin &alt3>;

  	gpioout: gpioout {
  		brcm,pins = <6>;
  		brcm,function = <1>; /* GPIO out */
  	};

-	alt0: alt0 {
-		brcm,pins = <0 1 2 3 4 5 7 8 9 10 11 14 15 40 45>;
+	gpioin: gpioin {
+		brcm,pins = <25>;
+		brcm,function = <0>; /* GPIO in */
+	};
+
+	spi0: spi0 {
+		brcm,pins = <8 9 10 11>; /* CS, MISO, MOSI, SCLK */
  		brcm,function = <4>; /* alt0 */
  	};

@@ -41,6 +46,24 @@
  	};
  };

+&spi {
+	status = "okay";
+	pinctrl-names = "default";
+	pinctrl-0 = <&spi0>;
+
+	qca7000: qca7000 at 0 {
+		compatible = "qca,qca7000";
+		spi-cpha;                         /* SPI mode: CPHA=1 */
+		spi-cpol;                         /* SPI mode: CPOL=1 */
+		spi-max-frequency = <8000000>;    /* freq: 8 MHz */
+		intr-gpios = <&gpioin 25 0>;      /* interrupt gpio */
+		interrupt-parent = <&gpio>;
+		interrupts = <2 25>;
+		linux,pluggable;
+		reg = <0x0>;                      /* CE0 */
+	};
+};
+
  &i2c0 {
  	status = "okay";
  	clock-frequency = <100000>;