Customizing the device tree VisionSOM-STM32MP1 - Revision history

KrzysztofChojnowski at 15:13, 20 January 2021

2021-01-20T15:13:29Z

← Older revision		Revision as of 15:13, 20 January 2021
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	== Manual changes ==		== Manual changes ==

	After copying new files to the ''meta-somlabs/mx/visionsom-dsi-mx/'' directory~~, however before compilation they need~~ some manual changes:		After copying new files to the ''meta-somlabs/mx/visionsom-dsi-mx/'' directory some manual changes are required for proper compilation:

	=== Include order ===		=== Include order ===

KrzysztofChojnowski at 15:12, 20 January 2021

2021-01-20T15:12:38Z

← Older revision		Revision as of 15:12, 20 January 2021
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	The device tree files for OpenSTlinux are generated by the STM32CubeMX toot available on the ST website: https://www.st.com/en/development-tools/stm32cubemx.html. In this article the version 5.6.1 of the tool is used.		The device tree files for OpenSTlinux are generated by the STM32CubeMX toot available on the ST website: https://www.st.com/en/development-tools/stm32cubemx.html. In this article the version 5.6.1 of the tool is used.

	The base projects generated for the VIsionSOM-STM32MP1 module and VisionCB-STM32MP1-STD board are available for the RGB (VisionSOM) and DSI (VisionSOM-dsi) displays. These projects may be obtained from the following repository:		The base projects generated for the VIsionSOM-STM32MP1 module and VisionCB-STM32MP1-STD board are available for the RGB (VisionSOM) and DSI (VisionSOM-dsi) displays. These projects may be obtained from the following repository (please checkout the proper branch according to your project settings):

	git clone https://github.com/SoMLabs/openst-cube-mx.git		git clone https://github.com/SoMLabs/openst-cube-mx.git
Line 27:		Line 27:
	[[File:visionsommp1_cubemx_3.png\|center\|800px]]		[[File:visionsommp1_cubemx_3.png\|center\|800px]]

	We can generate the new configuration which will be written in the CA7/DeviceTree/VisionSOM-dsi directory using the GENERATE CODE button in the top-right part of the application window.		We can generate the new configuration which will be written in the CA7/DeviceTree/VisionSOM-dsi directory using the GENERATE CODE button in the top-right part of the application window. All subdirectories (kernel, u-boot, tf-a) need to be copied to the meta-somlabs directory overwriting current ones.

	== Manual changes ==		== Manual changes ==

	~~We can copy the~~ new files to the ''meta-somlabs/mx/visionsom-dsi-mx/'' directory, however before compilation they need some manual changes:		After copying new files to the ''meta-somlabs/mx/visionsom-dsi-mx/'' directory, however before compilation they need some manual changes:

	=== Include order ===		=== Include order ===

			'''Only in thud version'''

	The includes order in the ''kernel/stm32mp157a-visionsom-dsi-mx.dts'' and ''u-boot/stm32mp157a-visionsom-dsi-mx.dts'' should be changed to:		The includes order in the ''kernel/stm32mp157a-visionsom-dsi-mx.dts'' and ''u-boot/stm32mp157a-visionsom-dsi-mx.dts'' should be changed to:
Line 44:		Line 46:

	=== pwm label ===		=== pwm label ===

			'''Only in thud version'''

	The label of the LED pwm (pwm1) needs to be restored (if used) in the ''kernel/stm32mp157a-visionsom-dsi-mx.dts'' and ''u-boot/stm32mp157a-visionsom-dsi-mx.dts'' files:		The label of the LED pwm (pwm1) needs to be restored (if used) in the ''kernel/stm32mp157a-visionsom-dsi-mx.dts'' and ''u-boot/stm32mp157a-visionsom-dsi-mx.dts'' files:

KrzysztofChojnowski at 14:33, 7 July 2020

2020-07-07T14:33:45Z

← Older revision		Revision as of 14:33, 7 July 2020
Line 2:		Line 2:

	This tutorial describes the procedure of customizing the device tree of the meta-somlabs layer used for the OpenSTLinux distribution. The detailed instruction of the system image compilation is available here [[OpenSTLinux for VisionSOM-STM32MP1\|here]]. As an example we will add the support of the USART3 of the STM32MP1 as the additional serial port that may be used from the Linux system. We will modify the device configuration files for the DSI display configuration.		This tutorial describes the procedure of customizing the device tree of the meta-somlabs layer used for the OpenSTLinux distribution. The detailed instruction of the system image compilation is available here [[OpenSTLinux for VisionSOM-STM32MP1\|here]]. As an example we will add the support of the USART3 of the STM32MP1 as the additional serial port that may be used from the Linux system. We will modify the device configuration files for the DSI display configuration.

			The detailed description of the device tree for particular peripherals is available on the ST wiki pages: https://wiki.st.com/stm32mpu/wiki/Category:Device_tree_configuration

	== Pre-generated device tree files ==		== Pre-generated device tree files ==

KrzysztofChojnowski: Created page with "{{PageHeader|Customizing the device tree}} toc This tutorial describes the procedure of customizing the device tree of the meta-somlabs layer used for the OpenSTLinux dis..."

2020-07-07T14:31:51Z

Created page with "{{PageHeader|Customizing the device tree}} __toc__ This tutorial describes the procedure of customizing the device tree of the meta-somlabs layer used for the OpenSTLinux dis..."

New page

{{PageHeader|Customizing the device tree}} __toc__

This tutorial describes the procedure of customizing the device tree of the meta-somlabs layer used for the OpenSTLinux distribution. The detailed instruction of the system image compilation is available here [[OpenSTLinux for VisionSOM-STM32MP1|here]]. As an example we will add the support of the USART3 of the STM32MP1 as the additional serial port that may be used from the Linux system. We will modify the device configuration files for the DSI display configuration.

== Pre-generated device tree files ==

The device tree files for OpenSTlinux are generated by the STM32CubeMX toot available on the ST website: https://www.st.com/en/development-tools/stm32cubemx.html. In this article the version 5.6.1 of the tool is used.

The base projects generated for the VIsionSOM-STM32MP1 module and VisionCB-STM32MP1-STD board are available for the RGB (VisionSOM) and DSI (VisionSOM-dsi) displays. These projects may be obtained from the following repository:

git clone https://github.com/SoMLabs/openst-cube-mx.git

== Modifying the project using STM32CubeMX ==

The downloaded projects may be open in the STM32CubeMX tool by loading the ioc file.

[[File:visionsommp1_cubemx_1.png|center|800px]]

In the application we have access to the GPIO, peripherals and the clock tree configuration. We can add the USART3 port in the Pinout & Configuration section by enabling it for Cortex-A7 non-secure context. In the pinout view (on the right) we can also modify the pin assignment to the selected peripheral. In this example the UART3-TX signal was linked to the PD8 pin.

[[File:visionsommp1_cubemx_2.png|center|800px]]

After the peripheral configuration, the clock is automatically enabled, however we can modify the clock source and frequency in the Clock Configuration window. In the example the clock source is PCLK1 (100MHz). In this tool we can also modify the clock sources and frequencies for the whole system.

[[File:visionsommp1_cubemx_3.png|center|800px]]

We can generate the new configuration which will be written in the CA7/DeviceTree/VisionSOM-dsi directory using the GENERATE CODE button in the top-right part of the application window.

== Manual changes ==

We can copy the new files to the ''meta-somlabs/mx/visionsom-dsi-mx/'' directory, however before compilation they need some manual changes:

=== Include order ===

The includes order in the ''kernel/stm32mp157a-visionsom-dsi-mx.dts'' and ''u-boot/stm32mp157a-visionsom-dsi-mx.dts'' should be changed to:

<pre>
#include "stm32mp157c.dtsi"
#include "stm32mp157cab-pinctrl.dtsi"
#include "stm32mp157c-m4-srm.dtsi"
</pre>

=== pwm label ===

The label of the LED pwm (pwm1) needs to be restored (if used) in the ''kernel/stm32mp157a-visionsom-dsi-mx.dts'' and ''u-boot/stm32mp157a-visionsom-dsi-mx.dts'' files:

<pre>
&timers1{
status = "okay";

/* USER CODE BEGIN timers1 */

/delete-property/dmas;
/delete-property/dma-names;

/* USER CODE END timers1 */

pwm1: pwm{
pinctrl-names = "default", "sleep";
pinctrl-0 = <&tim1_pwm_pins_mx>;
pinctrl-1 = <&tim1_pwm_sleep_pins_mx>;
status = "okay";

/* USER CODE BEGIN timers1_pwm */
/* USER CODE END timers1_pwm */
};
};
</pre>

=== Alias ===

In case of the serial ports a new alias needs to be added to the ''kernel/stm32mp157a-visionsom-dsi-mx.dts'' and ''u-boot/stm32mp157a-visionsom-dsi-mx.dts'' files:

<pre>
aliases {
ethernet0 = &ethernet0;
serial0 = &uart4;
serial1 = &uart7;
serial2 = &usart3;
mmc0 = &sdmmc1;
mmc1 = &sdmmc2;
};
</pre>

=== RGB panel u-boot configuration ===

If the RGB panel is used, the u-boot configuration in the ''u-boot/stm32mp157a-visionsom-dsi-mx.dts'' file needs to be restored according to the original version:

<pre>
panel {
status = "okay";
u-boot,dm-pre-reloc;
compatible = "simple-panel";
backlight = <&backlight>;
power-supply = <&vdd>;
enable-gpios = <&gpioa 1 GPIO_ACTIVE_LOW>;

display-timings {
timing0: timing0 {
clock-frequency = <33300000>;
hactive = <800>;
vactive = <480>;
hfront-porch = <210>;
hback-porch = <46>;
hsync-len = <46>;
vback-porch = <23>;
vfront-porch = <22>;
vsync-len = <23>;
hsync-active = <0>;
vsync-active = <0>;
de-active = <0>;
pixelclk-active = <1>;

};

};
};
</pre>

<pre>
&ltdc{
pinctrl-names = "default", "sleep";
pinctrl-0 = <&ltdc_pins_mx>;
pinctrl-1 = <&ltdc_sleep_pins_mx>;
status = "okay";

/* USER CODE BEGIN ltdc */

u-boot,dm-pre-reloc;

/* USER CODE END ltdc */
};
</pre>

When the new ''dts'' files are ready we can rebuilt and install the whole system or just the kernel sources (if only the ''kernel/stm32mp157a-visionsom-dsi-mx.dts'' file was modified):

<pre>
bitbake linux-stm32mp
</pre>

The ''dtb'' files are located in the ''tmp-glibc/deploy/images/stm32mp157a-visionsom-dsi-mx'' directory (some of them are symbolic links):

We can copy the correct ''dtb'' file to the ''bootfs'' partition and replace the existing one.

In this example, after rebuilding the system a new device will be available:

<pre>
/dev/ttySTM3
</pre>

Customizing the device tree VisionSOM-STM32MP1 - Revision history

KrzysztofChojnowski at 15:13, 20 January 2021

KrzysztofChojnowski at 15:12, 20 January 2021

KrzysztofChojnowski at 14:33, 7 July 2020

KrzysztofChojnowski: Created page with "{{PageHeader|Customizing the device tree}} __toc__ This tutorial describes the procedure of customizing the device tree of the meta-somlabs layer used for the OpenSTLinux dis..."

KrzysztofChojnowski: Created page with "{{PageHeader|Customizing the device tree}} toc This tutorial describes the procedure of customizing the device tree of the meta-somlabs layer used for the OpenSTLinux dis..."