Problem using 3 instances of SPIM on NRF52840 Zephyr RTOS

RE: Problem using 3 instances of SPIM on NRF52840 Zephyr RTOS

Ibrahimk — Wed, 19 Feb 2020 09:13:09 GMT

Solved 🙂

github.com/.../22893

RE: Problem using 3 instances of SPIM on NRF52840 Zephyr RTOS

Ibrahimk — Thu, 13 Feb 2020 15:00:14 GMT

Sorry for the latency

here are the project filesdevzone.nordicsemi.com/.../blenode.zip

Thanks for the help

RE: Problem using 3 instances of SPIM on NRF52840 Zephyr RTOS

Susheel Nuguru — Tue, 04 Feb 2020 07:23:05 GMT

Since you already have the setup to reproduce this, can you please give me a simplified project to test this. Will save a lot of my time trying to set it up.. Are you using Nordic Connect SDK or cloning Zephyr directly? which version ?
Once I reproduce it, we can try to figure out a workaround for this problem.

RE: Problem using 3 instances of SPIM on NRF52840 Zephyr RTOS

Ibrahimk — Fri, 31 Jan 2020 09:07:58 GMT

Thank you for your reply Susheel,

I also think there is a bug in the driver.

Having looked at the driver implementation of SPIM, I have not found any special treatment for the SPI 3 instance

RE: Problem using 3 instances of SPIM on NRF52840 Zephyr RTOS

Susheel Nuguru — Thu, 30 Jan 2020 11:28:41 GMT

smells like a bug in the driver. Let me reproduce this tomorrow and we can together agree on a workaround.

BTW, have you checked if the erratas workaround have been applied?

RE: Problem using 3 instances of SPIM on NRF52840 Zephyr RTOS

Ibrahimk — Thu, 30 Jan 2020 11:03:17 GMT

Thank you for your answer,

The behavior is that the device_get_binding() function does not return a reference to the SPI1 or SPI2 devices if either of them chooses SPIM driver and the SPI3 is enabled with SPIM.

The application keeps on restarting in this function before reaching the while(true) loop

static void spi_init(){
       spi_1_dev = device_get_binding("SPI_1");
       if(!spi_1_dev) printk("no SPI1!\n");
       else printk("found SPI1!\n");
       gpio_0_dev1 = device_get_binding("GPIO_0");
       if(!gpio_0_dev1) printk("no gpio_0_dev1!");
       cs1_control.delay = 0;
           cs1_control.gpio_dev = gpio_0_dev1;
        cs1_control.gpio_pin = 14;
       spi_1_cfg.cs = &cs1_control;

       spi_2_dev = device_get_binding("SPI_2");
       if(!spi_2_dev) printk("no Spi2!\n");
       else printk("found SPI2!\n");
       gpio_0_dev2 = device_get_binding("GPIO_0");
       if(!gpio_0_dev2) printk("no gpio_0_dev2!");
       cs2_control.delay = 0;
           cs2_control.gpio_dev = gpio_0_dev2;
        cs2_control.gpio_pin = 26;
        spi_2_cfg.cs = &cs2_control;

       spi_3_dev = device_get_binding("SPI_3");
       if(!spi_3_dev) printk("no SPI3\n");
       else printk("found SPI3!\n");
       gpio_0_dev3 = device_get_binding("GPIO_0");
       if(!gpio_0_dev3) printk("no gpio_0_dev3!");
       cs3_control.delay = 0;
           cs3_control.gpio_dev = gpio_0_dev3;
        cs3_control.gpio_pin = 24;
        spi_3_cfg.cs = &cs3_control;

}

the application would work if both SPI1 and SPI2 chooses the SPI driver without easyDMA but that is not the behavior I want

RE: Problem using 3 instances of SPIM on NRF52840 Zephyr RTOS

Susheel Nuguru — Thu, 23 Jan 2020 11:46:00 GMT

Also note that there are few Errata's on SPIM3, could affect the initialization of the driver. Check the code to see if the workarounds for these are applied. I would suggest not to use SPIM3, but that it your call.

RE: Problem using 3 instances of SPIM on NRF52840 Zephyr RTOS

Susheel Nuguru — Thu, 23 Jan 2020 11:37:13 GMT

haven't seen this myself, but what does it mean that the application start at all? So it does not reach to the main()? If so, there could be something in the driver initialization phase that fails that happens before the control reaches to main. Please start the program in the debugger to see what is the failure.