STM32MP157A-DK1 can't use I2C1 from Linux (Cortex A7)

[Ludovic Feltz]

Hello,

I'm trying to connect some sensors to the I2C1 connectors of the STM32MP157A-DK1 and read datas from a linux application (Cortex A7). It doesn't works...

But I successfully read data from the I2C5 connectors from the Cortex M4 processor.

I used the following configuration from STM32CubeMX for I2C1: 

But when i run

#i2cdetect -y 0
#i2cdetect -y 1
#i2cdetect -y 2

I don't see any of my devices:

 

Here is the DeviceTree file (located in "\CA7\DeviceTree\Monitoring\kernel\stm32mp157a-monitoring-mx.dts")

&i2c1{
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&i2c1_pins_mx>;
	pinctrl-1 = <&i2c1_sleep_pins_mx>;
	status = "okay";
 
	/* USER CODE BEGIN i2c1 */
	i2c-scl-rising-time-ns = <100>;
	i2c-scl-falling-time-ns = <7>;
	/delete-property/ dmas;
	/delete-property/ dma-names;
 
	hdmi-transmitter@39{
		compatible = "sil,sii9022";
		reg = <0x39>;
		iovcc-supply = <&v3v3_hdmi>;
		cvcc12-supply = <&v1v2_hdmi>;
		reset-gpios = <&gpioa 10 GPIO_ACTIVE_LOW>;
		interrupts = <1 IRQ_TYPE_EDGE_FALLING>;
		interrupt-parent = <&gpiog>;
		#sound-dai-cells = <0>;
		status = "okay";
 
		ports{
			#address-cells = <1>;
			#size-cells = <0>;
 
			port@0{
				reg = <0>;
 
				sii9022_in:endpoint{
					remote-endpoint = <&ltdc_ep0_out>;
				};
			};
 
			port@3{
				reg = <3>;
 
				sii9022_tx_endpoint:endpoint{
					remote-endpoint = <&i2s2_endpoint>;
				};
			};
		};
	};
 
	cs42l51:cs42l51@4a{
		compatible = "cirrus,cs42l51";
		reg = <0x4a>;
		#sound-dai-cells = <0>;
		VL-supply = <&v3v3>;
		VD-supply = <&v1v8_audio>;
		VA-supply = <&v1v8_audio>;
		VAHP-supply = <&v1v8_audio>;
		reset-gpios = <&gpiog 9 GPIO_ACTIVE_LOW>;
		clocks = <&sai2a>;
		clock-names = "MCLK";
		status = "okay";
 
		cs42l51_port:port{
			#address-cells = <1>;
			#size-cells = <0>;
 
			cs42l51_tx_endpoint:endpoint@0{
				reg = <0>;
				remote-endpoint = <&sai2a_endpoint>;
				frame-master;
				bitclock-master;
			};
 
			cs42l51_rx_endpoint:endpoint@1{
				reg = <1>;
				remote-endpoint = <&sai2b_endpoint>;
				frame-master;
				bitclock-master;
			};
		};
	};
	/* USER CODE END i2c1 */
};

What is wrong with my configuration?

I read that I2C1 is used by HDMI and some other devices on the DK1 board, does that mean i can't use it?

Can i use I2C5 from the Cortex M4 and the Cortex A7 at the same time?

[Ludovic Feltz]

Ok i just found that the Device Tree for Cortex A7 generated from STM32CubeMX is not automatically uploaded to the STM board when i run the M4 project.

The solution was to follow this tutorial to setup an OpenSTLinux project then run A7 project or manually copy generated .dtb to "/boot/stm32mp157a-dk1.dtb" (set correct card name)

I didn't see any documentation about this process? Something like : "How to use device tree generated by STMCubeMX"

Ok now i can read my I2C bus... But... I can't run the M4 project anymore from STMCubeIDE :sad_but_relieved_face:

I have the following logs when GDB is trying to attach:

Info : New GDB Connection: 2, Target STM32MP157AACx.cm4, state: reset
Warn : negative reply, retrying
Warn : negative reply, retrying
Warn : target STM32MP157AACx.cm4 is not halted (add breakpoint)
Error: can't add breakpoint: target running
Info : dropped 'gdb' connection
shutdown command invoked
Info : dropped 'gdb' connection

And nothing in "/sys/class/remoteproc/"

Any idea ?