-
Notifications
You must be signed in to change notification settings - Fork 2
iMX8 SPIDEV
vraevsky edited this page Dec 27, 2019
·
1 revision
This manual shows how to get SPIDEV work on CompuLab cl-som-imx8 boards.
Enable this CONFIG_SPI_SPIDEV in the kernel config file. It can be either Y or M.
The device tree location is at /path/to/kernel-tree/arch/arm64/boot/dts/compulab/cl-som-imx8-ecspi.dts
/*
* Copyright (C) 2018 CopuLab Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include "cl-som-imx8.dts"
/ {
model = "CompuLab CL-SOM-iMX8 rev1.1 on SBC-iMX8 (ecspi sample)";
compatible = "compulab,sbc-imx8", "compulab,cl-som-imx8,rev1.1", "compulab,cl-som-imx8", "fsl,imx8mq";
ecspi1: ecspi@30820000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "fsl,imx7d-ecspi", "fsl,imx51-ecspi";
reg = <0 0x30820000 0 0x10000>;
interrupts = ;
clocks = <&clk IMX8MQ_CLK_ECSPI1_ROOT>,
<&clk IMX8MQ_CLK_ECSPI1_ROOT>;
clock-names = "ipg", "per";
status = "disabled";
};
ecspi2: ecspi@30830000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "fsl,imx7d-ecspi", "fsl,imx51-ecspi";
reg = <0 0x30830000 0 0x10000>;
interrupts = ;
clocks = <&clk IMX8MQ_CLK_ECSPI2_ROOT>,
<&clk IMX8MQ_CLK_ECSPI2_ROOT>;
clock-names = "ipg", "per";
status = "disabled";
};
ecspi3: ecspi@30840000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "fsl,imx7d-ecspi", "fsl,imx51-ecspi";
reg = <0 0x30840000 0 0x10000>;
interrupts = ;
clocks = <&clk IMX8MQ_CLK_ECSPI3_ROOT>,
<&clk IMX8MQ_CLK_ECSPI3_ROOT>;
clock-names = "ipg", "per";
status = "disabled";
};
};
&iomuxc {
cl-som-imx8-ecspi {
pinctrl_ecspi1_sample: ecspi1_samplegrp {
fsl,pins = <
MX8MQ_IOMUXC_ECSPI1_SCLK_ECSPI1_SCLK 0x82 /* P1.13 */
MX8MQ_IOMUXC_ECSPI1_MOSI_ECSPI1_MOSI 0x82 /* P1.11 */
MX8MQ_IOMUXC_ECSPI1_MISO_ECSPI1_MISO 0x82 /* P1.15 */
MX8MQ_IOMUXC_ECSPI1_SS0_GPIO5_IO9 0x82 /* P1.17 */
>;
};
pinctrl_ecspi2_sample: ecspi2_samplegrp {
fsl,pins = <
MX8MQ_IOMUXC_ECSPI2_MOSI_ECSPI2_MOSI 0x82 /* P1.11 */
MX8MQ_IOMUXC_ECSPI2_MISO_ECSPI2_MISO 0x82 /* P1.15 */
MX8MQ_IOMUXC_ECSPI2_SCLK_ECSPI2_SCLK 0x82 /* P1.13 */
MX8MQ_IOMUXC_ECSPI2_SS0_GPIO5_IO13 0x82 /* P1.17 */
>;
};
pinctrl_ecspi3_sample: ecspi3_samplegrp {
fsl,pins = <
MX8MQ_IOMUXC_UART1_RXD_ECSPI3_SCLK 0x82 /* P1.69 */
MX8MQ_IOMUXC_UART1_TXD_ECSPI3_MOSI 0x82 /* P1.65 */
MX8MQ_IOMUXC_UART2_RXD_ECSPI3_MISO 0x82 /* P1.63 */
MX8MQ_IOMUXC_UART2_TXD_GPIO5_IO25 0x82 /* P1.58 */
>;
};
pinctrl_uart3_sample: uart3_samplegrp {
fsl,pins = <
MX8MQ_IOMUXC_UART3_TXD_UART3_DCE_TX 0x79
MX8MQ_IOMUXC_UART3_RXD_UART3_DCE_RX 0x79
>;
};
};
};
&uart3 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_uart3_sample>;
status = "okay";
};
/*
* Must be disabled; conflictis with ecspi2.
*/
&uart4 {
status = "disabled";
};
/* Rev 1.1 only */
&ecspi1 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi1_sample>;
fsl,spi-num-chipselects = <1>;
cs-gpios = <&gpio5 9 0>;
status = "okay";
spi@0 {
compatible = "spidev", "rohm,dh2228fv";
reg = <0>;
spi-max-frequency = <54000000>;
};
};
/* Rev 1.0 w/out WB only */
&ecspi2 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi2_sample>;
fsl,spi-num-chipselects = <1>;
cs-gpios = <&gpio5 13 0>;
status = "okay";
spi@0 {
compatible = "spidev", "rohm,dh2228fv";
reg = <0>;
spi-max-frequency = <54000000>;
};
};
&ecspi3 {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi3_sample>;
fsl,spi-num-chipselects = <1>;
cs-gpios = <&gpio5 25 0>;
status = "okay";
spi@0 {
compatible = "spidev", "rohm,dh2228fv";
reg = <0>;
spi-max-frequency = <54000000>;
};
};
While using this device tree, the system boots up and creates three spidev at /dev directory
crw------- 1 root root 153, 0 May 10 13:49 /dev/spidev0.0 crw------- 1 root root 153, 1 May 10 13:49 /dev/spidev1.0 crw------- 1 root root 153, 2 May 10 13:49 /dev/spidev2.0
- udevadm can be used also for getting the bus and device information on each device
udevadm info -ap /sys/bus/spi/devices/spi0.0
Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.
looking at device '/devices/platform/30820000.ecspi/spi_master/spi0/spi0.0':
KERNEL=="spi0.0"
SUBSYSTEM=="spi"
DRIVER=="spidev"
looking at parent device '/devices/platform/30820000.ecspi/spi_master/spi0':
KERNELS=="spi0"
SUBSYSTEMS=="spi_master"
DRIVERS==""
looking at parent device '/devices/platform/30820000.ecspi':
KERNELS=="30820000.ecspi"
SUBSYSTEMS=="platform"
DRIVERS=="spi_imx"
ATTRS{driver_override}=="(null)"
looking at parent device '/devices/platform':
KERNELS=="platform"
SUBSYSTEMS==""
DRIVERS==""
Feel free to get details at the official kernel spidev man pages: https://www.kernel.org/doc/Documentation/spi/spidev