Module libmctp::smbus

The SMBus specific protocol implementation.

This should be used when you want to communicate via MCTP over SMBus/I2C.

In order to use this you first need to create the main context struct. Then the get_request()/get_response() functions can be used to issue raw commands.

The libmctp library will not send the packets, instead it will create a buffer containing the data to be sent. This allows you to use your own SMBus/I2C implementation.

Generate a MCTP request

    use libmctp::control_packet::MCTPVersionQuery;
    use libmctp::smbus::{MCTPSMBusContext, VendorIDFormat};

    // The address of this device
    const MY_ID: u8 = 0x23;
    // Support vendor defined protocol 0x7E
    let msg_types: [u8; 1] = [0x7E];
    // Specify a PCI vendor ID that we support
    let vendor_ids = [VendorIDFormat {
        // PCI Vendor ID
        format: 0x00,
        // PCI VID
        data: 0x1414,
        // Extra data
        numeric_value: 4,
    }];
    let ctx = MCTPSMBusContext::new(MY_ID, &msg_types, &vendor_ids);

    let mut buf: [u8; 32] = [0; 32];

    const DEST_ID: u8 = 0x34;
    let len = ctx.get_request().get_mctp_version_support(
        DEST_ID,
        MCTPVersionQuery::MCTPBaseSpec,
        &mut buf,
    );

    // Send the request buf of length len via SMBus

Generate a MCTP response

    use libmctp::control_packet::{CompletionCode, MCTPVersionQuery};
    use libmctp::smbus::{MCTPSMBusContext, VendorIDFormat};

    // The address of this device
    const MY_ID: u8 = 0x23;
    // Support vendor defined protocol 0x7E
    let msg_types: [u8; 1] = [0x7E];
    // Specify a PCI vendor ID that we support
    let vendor_ids = [VendorIDFormat {
        // PCI Vendor ID
        format: 0x00,
        // PCI VID
        data: 0x1414,
        // Extra data
        numeric_value: 4,
    }];
    let ctx = MCTPSMBusContext::new(MY_ID, &msg_types, &vendor_ids);

    let mut buf: [u8; 32] = [0; 32];

    const DEST_ID: u8 = 0x34;
    let len = ctx.get_response().get_mctp_version_support(
        CompletionCode::Success,
        DEST_ID,
        &mut buf,
    );

    // Send the response buf of length len via SMBus

Decode a packet received

    use libmctp::control_packet::MCTPVersionQuery;
    use libmctp::smbus::{MCTPSMBusContext, VendorIDFormat};

    // The address of this device
    const MY_ID: u8 = 0x23;
    // Support vendor defined protocol 0x7E
    let msg_types: [u8; 1] = [0x7E];
    // Specify a PCI vendor ID that we support
    let vendor_ids = [VendorIDFormat {
        // PCI Vendor ID
        format: 0x00,
        // PCI VID
        data: 0x1414,
        // Extra data
        numeric_value: 4,
    }];
    let ctx = MCTPSMBusContext::new(MY_ID, &msg_types, &vendor_ids);
    let mut buf: [u8; 32] = [0; 32];

    // Receive data into buf from SMBus

    let ret = ctx.decode_packet(&buf);

    // Match and decode the returned value

Process a request to generate a response

    use libmctp::control_packet::MCTPVersionQuery;
    use libmctp::smbus::{MCTPSMBusContext, VendorIDFormat};

    // The address of this device
    const MY_ID: u8 = 0x23;
    // Support vendor defined protocol 0x7E
    let msg_types: [u8; 1] = [0x7E];
    // Specify a PCI vendor ID that we support
    let vendor_ids = [VendorIDFormat {
        // PCI Vendor ID
        format: 0x00,
        // PCI VID
        data: 0x1414,
        // Extra data
        numeric_value: 4,
    }];
    let ctx = MCTPSMBusContext::new(MY_ID, &msg_types, &vendor_ids);
    let mut buf_request: [u8; 32] = [0; 32];
    let mut buf_response: [u8; 32] = [0; 32];

    // Receive data into buf_request from SMBus

    let ret = ctx.process_packet(&buf_request, &mut buf_response);

    // Match and decode the returned value

Structs

MCTPSMBusContext	The global context for MCTP SMBus operations
VendorIDFormat	The Vendor ID Format as described in table 21