VAR-SOM-MX6 SPI: Difference between revisions

Revision as of 10:33, 30 October 2016

VAR-SOM-MX6 - SPI

Testing SPI from user space require some changes.

Configure your kernel and add spidev driver. Device Drivers -> SPI support -> <*> User mode SPI device driver support
Add spidev and pinctrl to your device tree

For VAR-SOM-MX6, edit arch/arm/boot/dts/imx6qdl-var-som.dtsi
For DART-MX6, edit arch/arm/boot/dts/imx6qdl-var-dart.dtsi

&ecspi1 {
	fsl,spi-num-chipselects = <1>;
	cs-gpios = <&gpio4 9 0>;
	pinctrl-names = "default";
	pinctrl-0 = <&pinctrl_ecspi1_1>;
	status = "okay";

        chip1: spidev@0 {
               compatible = "spidev";
               spi-max-frequency = <12000000>;
               reg = <0>;
        };
/*
        chip2: spidev@1 {
               compatible = "spidev";
               spi-max-frequency = <20000000>;
               reg = <1>;
	};
*/
};

pinctrl_ecspi1_1: ecspi1grp {
	fsl,pins = <
		MX6QDL_PAD_KEY_COL1__ECSPI1_MISO	0x100b1
		MX6QDL_PAD_KEY_ROW0__ECSPI1_MOSI	0x100b1
		MX6QDL_PAD_KEY_COL0__ECSPI1_SCLK	0x100b1
		MX6QDL_PAD_KEY_ROW1__GPIO4_IO09      0x80000000
	>;
};

Pick and choose the right chip select and you can also have multiple chip selects.

Compile the Linux kernel and device tree.
For testing use the application:
https://raw.githubusercontent.com/varigit/linux-2.6-imx/master/Documentation/spi/spidev_test.c

@@ Line 3: / Line 3: @@
 Testing SPI from user space require some changes.
 * Configure your kernel and add spidev driver. Device Drivers -> SPI support -> <*>   User mode SPI device driver support<br>
-* Add spidev to your device tree<br>
+* Add spidev and pinctrl to your device tree<br>
+For VAR-SOM-MX6, edit arch/arm/boot/dts/imx6qdl-var-som.dtsi<br>
+For DART-MX6, edit arch/arm/boot/dts/imx6qdl-var-dart.dtsi<br>
 <pre>&ecspi1 {
 	fsl,spi-num-chipselects = <1>;
 	cs-gpios = <&gpio4 9 0>;
 	pinctrl-names = "default";
-	pinctrl-0 = <&pinctrl_ecspi1_2>;
+	pinctrl-0 = <&pinctrl_ecspi1_1>;
 	status = "okay";
@@ Line 24: / Line 26: @@
 */
 };</pre>
+<pre>
+pinctrl_ecspi1_1: ecspi1grp {
+	fsl,pins = <
+		MX6QDL_PAD_KEY_COL1__ECSPI1_MISO	0x100b1
+		MX6QDL_PAD_KEY_ROW0__ECSPI1_MOSI	0x100b1
+		MX6QDL_PAD_KEY_COL0__ECSPI1_SCLK	0x100b1
+		MX6QDL_PAD_KEY_ROW1__GPIO4_IO09      0x80000000
+	>;
+};
+</pre>
 Pick and choose the right chip select and you can also have multiple chip selects.
 * Compile the Linux kernel and device tree.
 * For testing use the application:<br>https://raw.githubusercontent.com/varigit/linux-2.6-imx/master/Documentation/spi/spidev_test.c