Is there a problem with SPI communication of ncs1.9.0 SDK?

[duxinglang]

I used to use the ncs1.2.0 SDK to develop a product for customers. Now I am porting it to the ncs1.9.0 SDK. During the adaptation process, I find that its control over SPI is very different from that before. When the 1.2.0 version of SPI communicates, the CS signal will be lowered, making the peripherals selected; However, in version 1.9.0, I found that its definition of CS signal was just the opposite. During communication, it pulled the CS signal high, which led to my peripheral unable to receive data. Why did this happen? Where can I set it or is this a bug?

This is the waveform diagram of SPI communication in ncs1.9.0

This is the waveform diagram of SPI communication in ncs1.2.0.

[Einarh]

Hello!

You should be able to set the CS polarity in your SPI configuration:

http://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/hardware/peripherals/spi.html#c.spi_config

What does your current SPI configuration look like?

Best regards,

Einar

[duxinglang]

Hi, this is my spi cpnfiguration:

static void LCD_SPI_Init(void)
{
	spi_lcd = device_get_binding(LCD_DEV);
	if(!spi_lcd) 
	{
		printk("Could not get %s device\n", LCD_DEV);
		return;
	}

	spi_cfg.operation = SPI_OP_MODE_MASTER | SPI_WORD_SET(8);
	spi_cfg.frequency = 8000000;
	spi_cfg.slave = 0;

	spi_cs_ctr.gpio_dev = device_get_binding(LCD_PORT);
	if (!spi_cs_ctr.gpio_dev)
	{
		printk("Unable to get GPIO SPI CS device\n");
		return;
	}

	spi_cs_ctr.gpio_pin = CS;
	spi_cs_ctr.delay = 0U;
	spi_cfg.cs = &spi_cs_ctr;
}

[Einarh]

I can't see that you've set the CS polarity, so you should try doing that.

How is your spi_cfg struct defined?

[duxinglang]

Yes, I see SPI_ CS_ ACTIVE_ High is the setting item, but what I need is that the CS signal is effective at low level. I don't see SPI_ CS_ ACTIVE_ Low this option.

[Einarh]

I believe you should get active low by setting cs_active_high to 0

[duxinglang]

No matter I put gpio_dt_flags set to GPIO_ACTIVE_HIGH or GPIO_ACTIVE_LOW, the waveforms I see from the logic analyzer are all high-level, which is very strange. like this:

static void LCD_SPI_Init(void)
{
	spi_lcd = device_get_binding(LCD_DEV);
	if(!spi_lcd) 
	{
		return;
	}

	spi_cfg.operation = SPI_OP_MODE_MASTER | SPI_WORD_SET(8);
	spi_cfg.frequency = 8000000;
	spi_cfg.slave = 0;

	spi_cs_ctr.gpio_dev = device_get_binding(LCD_PORT);
	if(!spi_cs_ctr.gpio_dev)
	{
		return;
	}

	spi_cs_ctr.gpio_pin = CS;
	spi_cs_ctr.delay = 0U;
	spi_cs_ctr.gpio_dt_flags = GPIO_ACTIVE_LOW;//GPIO_ACTIVE_HIGH
	spi_cfg.cs = &spi_cs_ctr;	
}

[Einarh]

Have you tried setting spi_cfg.cs_active_high = 0?