Device not found with device_get_binding

Question

Hi,

I'm trying to mount two spi flash device on spi0, but can't found the second one(device_get_binding() return NULL).

The two device has compatible ("jedec,spi-nor") mean they has spi-nor flash driver.

My main functions like this:

#define FLASH_DEVICE_0 "DEVICE_LABEL_0"
#define FLASH_DEVICE_1 "DEVICE_LABEL_1"

static void device_0(void) {
  const struct device *flash_dev = device_get_binding(FLASH_DEVICE_0);

  if (!flash_dev) {
    LOG_INF("SPI flash driver %s was not found!", __func__);
    return;
  }

  LOG_INF("Get %s.", __func__);
}

static void device_1(void) {
  const struct device *flash_dev = device_get_binding(FLASH_DEVICE_1);

  if (!flash_dev) {
    LOG_INF("SPI flash driver %s was not found!", __func__);
    return;
  }

  LOG_INF("Get %s.", __func__);
}

void main(void) {
  LOG_INF("Hello");
  device_0();
  device_1();
}

And i add app.overlay to my project. Because of no actual device was connected, i just make MISO to GND, so jedec-id is zero.

&spi0 {
    compatible = "nordic,nrf-spi";
    status = "okay";
    pinctrl-0 = <&spi_default>;
    pinctrl-1 = <&spi_sleep>;
    pinctrl-names = "default", "sleep";
    cs-gpios = <&gpio0 28 GPIO_ACTIVE_LOW>, <&gpio0 30 GPIO_ACTIVE_LOW>;

    DEVICE_0:DEVICE_0@0 {
        compatible = "jedec,spi-nor";
        reg = <0>;
        spi-max-frequency = <8000000>;
        label = "DEVICE_LABEL_0";
        jedec-id = [ 00 00 00 ];
        size = < 0x8000000 >;
    };
    DEVICE_1:DEVICE_1@1 {
        compatible = "jedec,spi-nor";
        reg = <1>;
        spi-max-frequency = <8000000>;
        label = "DEVICE_LABEL_1";
        jedec-id = [ 00 00 00 ];
        size = < 0x8000000 >;
    };
};

After download zephyr.hex to nRF52840, the RTT View shows as follow:

*** Booting Zephyr OS build v3.0.99-ncs1  ***

[00:00:00.331,207] <inf> multi_spi: Hello
[00:00:00.331,237] <inf> multi_spi: Get device_0.
[00:00:00.331,268] <inf> multi_spi: SPI flash driver device_1 was not found!

It is shows that "device 0" can found but "device 1" can NOT found. I debug it and see z_impl_device_get_binding() has a device named "device 0", but no device named "device 1".

"device 1" can be only found when i was deleted "device 0" on the app.overlay file.

what does i missing?

Einarh · Accepted Answer

>Do you means i only add one device and two CS pins in my app.overlay file, and select the device by CS pin? 
 Yes 
 > The spi flash has four pins such as "CS", "CLK", "MOSI", "MISO". And the EPD display has extra two pins. 
 >But i don't have enough PINs, so i have to reuse some pins which is spi flash and EPD display in this case. 
 This is exactly why you have the CS pin. 
 You don't define your peripheral devices in the devicetree, you only define the SPI bus device and then use the SPI bus to talk to your peripheral devices.

Device not found with device_get_binding

Top Replies