Linux Device Drivers Development

Driver and device provisioning

As we need i2c_device_id for I2C devices, we must use spi_device_id for SPI devices, in order to provide a device_id array to match our devices. It is defined in include/linux/mod_devicetable.h:

struct spi_device_id { 
   char name[SPI_NAME_SIZE]; 
   kernel_ulong_t driver_data; /* Data private to the driver */ 
}; 

We need to embed our array into a struct spi_device_id, in order to inform the SPI core about the device ID we need to manage in the driver, and call the MODULE_DEVICE_TABLE macro on the driver structure. Of course, the first parameter of the macro is the name of the bus on which the device sits. In our case, it is SPI:

#define ID_FOR_FOO_DEVICE 0 #define ID_FOR_BAR_DEVICE 1 static struct spi_device_id foo_idtable[] ...