gizhw:bus

the buses a board exposes: a serial port's speed (termios2, any rate through BOTHER), GPIO lines (the character device's chardev v2 interface: a line request, then its values), I2C transfers (I2C_RDWR), SPI transfers (SPI_IOC_MESSAGE), USB control transfers (usbfs), and CAN frames (SocketCAN, raw). The ioctl numbers and the structs are the kernel's (termios.h, gpio.h, i2c-dev.h, spidev.h, usbdevice_fs.h, can.h), checked against those headers. Every ioctl is on a Handle of gizhw:device; the CAN socket and the interface lookup are libc calls through libcCall.

import * as Bus from "gizhw:bus";

Types

I2cMessage

type I2cMessage = { address: i64; read: bool; length: i64; data: bytes; }

One I2C message: the 7-bit address, read (true: length bytes come back) or the data to write.

• address: i64
• read: bool
• length: i64
• data: bytes

CanFrame

type CanFrame = { id: i64; extended: bool; data: bytes; }

One CAN frame: its identifier, whether it is an extended (29-bit) one, and its data (up to 8 bytes).

• id: i64
• extended: bool
• data: bytes

Functions

termiosRate

function termiosRate(termios: bytes, baud: i64): bytes

The serial port's termios2 with the speed set: both directions at baud, through BOTHER.

Effects: fail.

serialRate

function serialRate(h: Device.Handle, baud: i64): void throws string

Sets the serial port behind h to baud.

Effects: fail, io.

lineRequest

function lineRequest(offset: i64, flags: i64, consumer: string): bytes

The request for GPIO_V2_GET_LINE: one line of the chip (its offset), as an input or an output, under consumer.

Effects: fail.

parseLineFd

function parseLineFd(reply: bytes): i64

The line's file descriptor in the reply to GPIO_V2_GET_LINE (at byte 588).

Effects: fail.

valuesRequest

function valuesRequest(bits: i64, mask: i64): bytes

The request for GPIO_V2_LINE_GET/SET_VALUES: the bit values and the mask of the lines it touches (bit 0: the line).

Effects: fail.

parseLineValue

function parseLineValue(reply: bytes): i64

The value of the one line the reply to GPIO_V2_LINE_GET_VALUES describes: 0 or 1.

Effects: fail.

gpioRead

function gpioRead(sys: System, chip: Device.Handle, offset: i64): i64 throws string

Reads GPIO line offset of the chip behind chip (its character device, /dev/gpiochipN): a line request, then its value.

Effects: fail, io.

gpioWrite

function gpioWrite(sys: System, chip: Device.Handle, offset: i64, value: i64): void throws string

Sets GPIO line offset of the chip behind chip to value (0 or 1), as an output.

Effects: fail, io.

i2cMessageBytes

function i2cMessageBytes(address: i64, flags: i64, length: i64, buffer: u64): bytes

One I2C message (struct i2c_msg: 16 bytes): address, flags, length, and the buffer's native address.

Effects: fail.

i2cRdwrBytes

function i2cRdwrBytes(messages: u64, count: i64): bytes

The I2C_RDWR argument (struct i2c_rdwr_ioctl_data: 16 bytes): the messages' native address and their count.

Effects: fail.

i2c

function i2c(h: Device.Handle, messages: Vec<I2cMessage>): Vec<bytes> throws string

Runs I2C messages on the bus behind h, one transaction; gives each read's bytes (empty for a write).

Effects: fail, io.

spiTransferBytes

function spiTransferBytes(tx: u64, rx: u64, length: i64, speed: i64, bits: i64): bytes

The SPI transfer (struct spi_ioc_transfer: 32 bytes): the tx and rx buffers, the length, speed and bits per word.

Effects: fail.

spi

function spi(h: Device.Handle, tx: bytes, rxLength: i64, speed: i64): bytes throws string

One SPI transfer on the device behind h: tx out, and rxLength bytes back; gives those bytes.

Effects: fail, io.

usbCtrlBytes

function usbCtrlBytes(requestType: i64, request: i64, value: i64, index: i64, length: i64, timeout: i64, data: u64): bytes

The usbfs control transfer (struct usbdevfs_ctrltransfer: 24 bytes).

Effects: fail.

usbControl

function usbControl(h: Device.Handle, requestType: i64, request: i64, value: i64, index: i64, data: bytes, readLength: i64, timeout: i64): bytes throws string

A control transfer on the device behind h. A device-to-host one (requestType with the IN bit) reads readLength bytes back; a host-to-device one sends data. Gives the bytes that came back (empty for a send).

Effects: fail, io.

canFrameBytes

function canFrameBytes(frame: CanFrame): bytes

A CAN frame as struct can_frame (16 bytes): the identifier (with the extended bit), the data length, and the data.

Effects: fail.

parseCanFrame

function parseCanFrame(data: bytes): CanFrame

The CAN frame from its 16 bytes.

Effects: fail.

canOpen

function canOpen(sys: System, name: string): Device.Handle throws string

The CAN interface name (can0) as a raw SocketCAN handle: the socket is bound to the interface.

Effects: fail, io.

canSend

function canSend(h: Device.Handle, frame: CanFrame): i64 throws string

Sends one frame on the CAN handle; gives the bytes written (16).

Effects: fail, io.

canReceive

function canReceive(h: Device.Handle): CanFrame throws string

Receives one frame from the CAN handle, waiting for it.

Effects: fail, io.