Module gpio 

The C ABI for on-board bus addressing and pin logic.

These functions wrap [pamoja_gpio] for callers that reach the SDK through the flat C boundary: I2C addressing per NXP UM10204, the four SPI clock modes, the pin model that maps a logical “asserted” onto a physical level, and a line opened on a Linux board.

The addressing and the pin model allocate nothing and hold no state. An I2C address is two scalars and crosses by value as PamojaI2cAddress; the rest are enumerations and small pure functions over them. A PamojaGpioLine is the one handle: a line on a Linux board’s GPIO chip, opened with pamoja_gpio_line_open_output or pamoja_gpio_line_open_input and let go with pamoja_gpio_line_free. On any other platform opening one returns PamojaStatus::Unsupported with a message saying why.

Structs

PamojaGpioLine

A GPIO line opened on a Linux board. Opaque; let it go with pamoja_gpio_line_free, which hands the line back to the kernel.

PamojaI2cAddress

A validated I2C device address.

Enums

PamojaI2cDirection

Which direction an I2C transfer runs, as the read/write bit encodes it.

PamojaPinEdge

The signal transition that triggers a pin interrupt.

PamojaPinLevel

The physical voltage level on a pin.

PamojaPinPolarity

Whether a signal is asserted by a high or a low physical level.

Constants

PAMOJA_I2C_FRAME_MAX

The largest I2C address frame, in bytes: the two a 10-bit address needs.

PAMOJA_I2C_RESERVED_BELOW

The first 7-bit address above the reserved block at the bottom of the range.

PAMOJA_I2C_RESERVED_FROM

The lowest 7-bit address the I2C specification keeps for itself.

Functions

pamoja_gpio_line_drive^⚠

Drives an output line to a level.

pamoja_gpio_line_free^⚠

Lets a line go, handing it back to the kernel. A null pointer is ignored.

pamoja_gpio_line_open_input^⚠

Opens a line on a Linux board as an input.

pamoja_gpio_line_open_output^⚠

Opens a line on a Linux board as an output, driving initial from the moment it is taken.

pamoja_gpio_line_read^⚠

Reads the level on a line now.

pamoja_i2c_address_frame^⚠

Writes the address bytes a controller puts on the bus for a transfer.

pamoja_i2c_address_frame_len

Returns how many bytes an address frame occupies.

pamoja_i2c_address_is_general_call

Reports whether an address is the general call address 0x00.

pamoja_i2c_address_is_reserved

Reports whether a 7-bit address falls in a range the I2C specification reserves.

pamoja_i2c_address_seven_bit^⚠

Validates a 7-bit I2C address.

pamoja_i2c_address_ten_bit^⚠

Validates a 10-bit I2C address.

pamoja_pin_edge_triggered_by

Reports whether a change from one level to another fires an interrupt trigger.

pamoja_pin_level_from_bool

Returns the level a boolean names.

pamoja_pin_level_inverted

Returns the opposite level.

pamoja_pin_polarity_is_asserted

Reports whether a physical level means the signal is asserted.

pamoja_pin_polarity_level

Returns the physical level that represents a logical state under a polarity.

pamoja_spi_mode_cpol_cpha^⚠

Returns the (CPOL, CPHA) pair an SPI mode number names.

pamoja_spi_mode_from_cpol_cpha

Returns the SPI mode number a (CPOL, CPHA) pair names.