Enabling spidev on iMX8 Solidrun Hummingboard Pulse

garyg — Thu, 12 Mar 2020 15:41:38 GMT

It's been nearly one year since I requested, both in their forum and here but still no solution. Other vendor like CompuLab here have a solution to change their dts to support spidev, but not SolidRun.

Checking from their dts even in the latest sr-imx8-debian-bullseye-20191201-cli-imx8mq-sdh.. image, it seems like all ecspi0,1,2 are still disabled. The HBPulse has a mikroBus interface that uses ecspi2, so this is the bus that I would like to enable. I tried changing to status to 'okay', but apparently I need to also add another node to the dts with the following entry. I'm not sure what to fill in the pinctrl-0, cs-gpios, and reg fields? Perhaps someone can look at the HbPulse schematic that I attached and provide me the info?

&ecspi2 {
   #address-cells = <1>;
   #size-cells = <0>;
   fsl,spi-num-chipselects = <1>;
   pinctrl-names = "default";
   pinctrl-0 = <&pinctrl_ecspi2 &pinctrl_ecspi2_cs>;
   cs-gpios = <&gpio5 13 GPIO_ACTIVE_LOW>;
   status = "okay";
   spidev0: spi@0 {
       reg = <0>;
       compatible = "epson,s1d13c00";
       spi-max-frequency = <500000>;
   };
};

After some readings about dtb in general this is the modified:

        ecspi@30830000 {
                #address-cells = <0x01>;
                #size-cells = <0x00>;
                compatible = "spidev,fsl,imx8mq-ecspi\0fsl,imx51-ecspi";
                reg = <0x00 0x30830000 0x00 0x10000>;
                interrupts = <0x00 0x20 0x04>;
                clocks = <0x04 0xc2 0x04 0xc2>;
                clock-names = "ipg\0per";
                status = "okay";
                fsl,spi-num-chipselects = <1>;
                pinctrl-names = "default";
                pinctrl-0 = <&pinctrl_ecspi2 &pinctrl_ecspi2_cs>;
                cs-gpios = <&gpio5 13 GPIO_ACTIVE_LOW>;
                spidev0: spi@0 {
                        reg = <0>;
                        compatible = "spidev";
                        spi-max-frequency = <500000>;
                        status = "okay";
                };

The pinctrl that handles io muxing is very complex and I'm still yet to know what to define, there is no pinctrl_ecspi2 defined anywhere in the dts.

Useful reference regarding imx8 to help modify the dts:

pinfunc - linux/imx8mq-pinfunc.h at master · torvalds/linux · GitHub

Device Tree Customization

linux/arch/arm64/boot/dts/freescale at master · torvalds/linux · GitHub

https://www.nxp.com/docs/en/user-guide/i.MX_BSP_Porting_Guide_Linux.pdf (pg.31-32)

Serial Peripheral Interface (SPI)

Really wish these could be enabled by default.

Re: Enabling spidev on iMX8 Solidrun Hummingboard Pulse

igorpadykov — Thu, 12 Mar 2020 23:31:32 GMT

Hi Gary

one can look at attached ecspi2 example for boundary devices nitrogen8m

board, and make appropriate pinmuxing changes for used board:

GitHub - boundarydevices/linux-imx6 at boundary-imx_4.14.x_2.0.0_ga

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

i.MX Processors中的主题 Re: Enabling spidev on iMX8 Solidrun Hummingboard Pulse

Enabling spidev on iMX8 Solidrun Hummingboard Pulse

Re: Enabling spidev on iMX8 Solidrun Hummingboard Pulse