I'm implementing the server side of a FTMS Control Point attribute in an application and am struggling to understand how to implement 'write with response'.
The definition of the attribute seems straight-forward:
BT_GATT_CHARACTERISTIC(BLUE_UUID_FITNESS_CONTROL_POINT_CHAR, BT_GATT_CHRC_WRITE, BT_GATT_PERM_WRITE, NULL, write_control, NULL),
I pass in a _write callback and use the BT_GATT_CHRC_WRITE characteristic. But what I don't understand is where is the response implemented? From the documentation bt_gatt_attr_write_func_t expects that I return the length of bytes written. But where/how does the response happen? Looking in `gatt.h`, all I can find related to the response is client side.
