Tokio UHID

A safe wrapper around the userspace API to the HID subsystem in the linux kernel.

Example

use tokio_linux_uhid::{Bus, CreateParams, UHIDDevice};

// Formulate a 'HID Report Descriptor' to describe the function of your device.
// This tells the kernel how to interpret the HID packets you send to the device.
const RDESC: [u8; 85] = [
    0x05, 0x01,	/* USAGE_PAGE (Generic Desktop) */
    0x09, 0x02,	/* USAGE (Mouse) */
    0xa1, 0x01,	/* COLLECTION (Application) */
    0x09, 0x01,		/* USAGE (Pointer) */
    0xa1, 0x00,		/* COLLECTION (Physical) */
    0x85, 0x01,			/* REPORT_ID (1) */
    0x05, 0x09,			/* USAGE_PAGE (Button) */
    0x19, 0x01,			/* USAGE_MINIMUM (Button 1) */
    0x29, 0x03,			/* USAGE_MAXIMUM (Button 3) */
    0x15, 0x00,			/* LOGICAL_MINIMUM (0) */
    0x25, 0x01,			/* LOGICAL_MAXIMUM (1) */
    0x95, 0x03,			/* REPORT_COUNT (3) */
    0x75, 0x01,			/* REPORT_SIZE (1) */
    0x81, 0x02,			/* INPUT (Data,Var,Abs) */
    0x95, 0x01,			/* REPORT_COUNT (1) */
    0x75, 0x05,			/* REPORT_SIZE (5) */
    0x81, 0x01,			/* INPUT (Cnst,Var,Abs) */
    0x05, 0x01,			/* USAGE_PAGE (Generic Desktop) */
    0x09, 0x30,			/* USAGE (X) */
    0x09, 0x31,			/* USAGE (Y) */
    0x09, 0x38,			/* USAGE (WHEEL) */
    0x15, 0x81,			/* LOGICAL_MINIMUM (-127) */
    0x25, 0x7f,			/* LOGICAL_MAXIMUM (127) */
    0x75, 0x08,			/* REPORT_SIZE (8) */
    0x95, 0x03,			/* REPORT_COUNT (3) */
    0x81, 0x06,			/* INPUT (Data,Var,Rel) */
    0xc0,			/* END_COLLECTION */
    0xc0,		/* END_COLLECTION */
    0x05, 0x01,	/* USAGE_PAGE (Generic Desktop) */
    0x09, 0x06,	/* USAGE (Keyboard) */
    0xa1, 0x01,	/* COLLECTION (Application) */
    0x85, 0x02,		/* REPORT_ID (2) */
    0x05, 0x08,		/* USAGE_PAGE (Led) */
    0x19, 0x01,		/* USAGE_MINIMUM (1) */
    0x29, 0x03,		/* USAGE_MAXIMUM (3) */
    0x15, 0x00,		/* LOGICAL_MINIMUM (0) */
    0x25, 0x01,		/* LOGICAL_MAXIMUM (1) */
    0x95, 0x03,		/* REPORT_COUNT (3) */
    0x75, 0x01,		/* REPORT_SIZE (1) */
    0x91, 0x02,		/* Output (Data,Var,Abs) */
    0x95, 0x01,		/* REPORT_COUNT (1) */
    0x75, 0x05,		/* REPORT_SIZE (5) */
    0x91, 0x01,		/* Output (Cnst,Var,Abs) */
    0xc0,		/* END_COLLECTION */
];

fn main() {
    // All the parameters used to create the HID device
    let create_params = CreateParams {
        name: String::from("test-uhid-device"),
        phys: String::from(""),
        uniq: String::from(""),
        bus: Bus::USB,
        vendor: 0x15d9,
        product: 0x0a37,
        version: 0,
        country: 0,
        // Most inportant field - HID Report Descriptor
        data: RDESC.to_vec(),
    };

    let core = tokio_core::reactor::Core::new().unwrap();
    let handle = core.handle();
    // Give the UHID device a handle to the tokio event loop and the create parameters
    let mut uhid_device = UHIDDevice::create(&handle, create_params, None).unwrap();

    // Formulate a HID Packet
    let button_flags = 0;
    let mouse_abs_hor = 20;
    let mouse_abs_ver = 0;
    let wheel = 0;
    let data: [u8; 5] = [1, button_flags, mouse_abs_hor, mouse_abs_ver, wheel];
    
    // Send the HID packet to the device. Cursor should move 20 points to the right. 
    uhid_device.send_input(&data).unwrap();
}