STM32F4 adc dma crashing

[rijesha]

Describe the bug
I am trying to read 4 adc channels simultaneously with an STM32F411. The adc_read call only allows a single channel to be read with STM32 if not using DMA. This issue has been brought up a few times and the answer has generally been to be use DMA. There are a few issues related to it for example #19882 #34656 #32288 #39640

#52965 Is the pull request that provided STM32 ADC DMA support. None of the code examples I can find work for F4 chips. The test code in test/drivers/adc/adc_dma has code examples for H7, L4 and U5 chips, but not F4 chips.

The F4 chips use the st,stm32f4-adc and the st,stm32-dma-v1 node.

I tried running the test code with a stm32f4 board, but the MCU always resets when the dma_config function calls api->config(dev, channel, config); (Line 345 of include/zephyr/drivers/dma.h) The adc code calls dma_config from drivers/adc/adc_stm32.c adc_stm32_dma_start function.

DTS File:

#include <st/f4/stm32f411Xe.dtsi>
#include <st/f4/stm32f411r(c-e)tx-pinctrl.dtsi>
#include <zephyr/dt-bindings/input/input-event-codes.h>
.
.
.

&adc1 {
	pinctrl-0 = <&adc1_in10_pc0 &adc1_in11_pc1
	&adc1_in12_pc2 &adc1_in13_pc3 &adc1_in1_pa1>;
	pinctrl-names = "default";
	st,adc-clock-source = <SYNC>;
	st,adc-prescaler = <2>;
	status = "okay";

	dmas = < &dma1 0 0 (STM32_DMA_PERIPH_TO_MEMORY |
	STM32_DMA_MEM_INC |  STM32_DMA_MEM_16BITS | STM32_DMA_PERIPH_16BITS) 0x3>;
	dma-names = "dma";

	#address-cells = <1>;
	#size-cells = <0>;

	channel@1 {
		reg = <1>;
		zephyr,gain = "ADC_GAIN_1";
		zephyr,reference = "ADC_REF_INTERNAL";
		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
		zephyr,resolution = <12>;
	};

	channel@10 {
		reg = <10>;
		zephyr,gain = "ADC_GAIN_1";
		zephyr,reference = "ADC_REF_INTERNAL";
		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
		zephyr,resolution = <12>;
	};

	channel@11 {
		reg = <11>;
		zephyr,gain = "ADC_GAIN_1";
		zephyr,reference = "ADC_REF_INTERNAL";
		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
		zephyr,resolution = <12>;
	};

	channel@12 {
		reg = <12>;
		zephyr,gain = "ADC_GAIN_1";
		zephyr,reference = "ADC_REF_INTERNAL";
		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
		zephyr,resolution = <12>;
	};

	channel@13 {
		reg = <13>;
		zephyr,gain = "ADC_GAIN_1";
		zephyr,reference = "ADC_REF_INTERNAL";
		zephyr,acquisition-time = <ADC_ACQ_TIME_DEFAULT>;
		zephyr,resolution = <12>;
	};
};

test_dma: &dma1 {
    status = "okay";
};

And I have the following in my config file:

CONFIG_ADC=y
CONFIG_DMA=y
CONFIG_ADC_STM32_DMA=y
CONFIG_ADC_ASYNC=y

Environment (please complete the following information):

• OS: Windows
• Zephyr 3.4.99

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[rijesha]

I should also mention that I do get this build warning:

unit address and first address in 'reg' (0xa) don't match for /soc/adc@40012000/channel@10
unit address and first address in 'reg' (0xb) don't match for /soc/adc@40012000/channel@11
unit address and first address in 'reg' (0xc) don't match for /soc/adc@40012000/channel@12
unit address and first address in 'reg' (0xd) don't match for /soc/adc@40012000/channel@13

[gautierg-st]

Support for the ADC sequencer (for all STM32 series except F1) has been integrated in PR #62436 (present in v3.5.0).
Work has also been done on DMA support in this PR #65429 (current main and future 3.6.0).
I invite you to have a look at these if they can solve your problem.

I should also mention that I do get this build warning:

unit address and first address in 'reg' (0xa) don't match for /soc/adc@40012000/channel@10
unit address and first address in 'reg' (0xb) don't match for /soc/adc@40012000/channel@11
unit address and first address in 'reg' (0xc) don't match for /soc/adc@40012000/channel@12
unit address and first address in 'reg' (0xd) don't match for /soc/adc@40012000/channel@13

The number after @ is in hexadecimal. So if you are reading at register address 0xa (ie decimal 10), it should be channel@a

[rijesha]

Thanks. I have upgraded to v3.5.0 and am reading the ADC sequence with a separate thread. This seems to be working for now and Ill will probably change to DMA once v3.6.0 comes out.

[rijesha]

Issue is and will be further resolved in future releases

[rijesha]

I have done more testing and ran into issues.
The adc_read function with v3.5.0 ends up hanging after a while. I have the code in a while loop and randomly the loop will stall. With some experimenting it seems like the loop stall quicker when zephyr,acquisition-time is set to ADC_ACQ_TIME_DEFAULT rather than ADC_ACQ_TIME_MAX.

while (true)
{
	int ret = adc_read_dt(&adc_channels[0], &sequence);
	if (ret == 0)
	{
		got_new_data = true;
	}
	k_msleep(10);
}

I have also tried the latest main with DMA. That is not working either. The STM32F4 doesn't have the function LL_ADC_REG_StopConversion. This function is called on line 770 of drivers/adc/adc_stm32.c.
I commented out the line. With the line commented out the signal is never set and the buffer doesnt fill with data.