Set the Configuration Descriptors

Introduction

The configuration descriptor contains values required by the class drivers. The settings are:

• number of interfaces in the configuration,

• maximum power taken by the device,

• is remote wakeup enabled.

Note: that the number of interfaces in the configuration must be set, all the other settings are optional.

TInt desc_size = 0;
gPort.GetConfigurationDescriptorSize(desc_size);

The size should normally be KUsbDescSize_Config as defined in <usb.h>

Setting configuration descriptors

Set the configuration descriptor using RDevUsbcScClient::SetConfigurationDescriptor().

TBuf8<desc_size> descriptor;

// Invert Remote-Wakup support
descriptor[KConfDesc_AttribOffset] = (descriptor[KConfDesc_AttribOffset] ^ KUsbDevAttr_RemoteWakeup);

// Change the reported max power to 200mA (2 * 0x64)
descriptor[KConfDesc_MaxPowerOffset] = 0x64;
r = gPort.SetConfigurationDescriptor(descriptor);

Additional values may be set using the RDevUsbcScClient class. These values can be set, retrieved and removed:

• Manufacturer,

• Product,

• Serial numbers.

After you have set the configuration descriptors you should Set the Interface Descriptors.