mcp2221_gpio.h File Reference

Direct GPIO input and output helpers. More...

#include <stdint.h>
#include "mcp2221.h"

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Classes
struct	mcp2221_gpio_write_t
	Per-pin GPIO output update request. More...

Macros
#define	MCP2221_GPIO_KEEP   (-1)
	Preserve the current GPIO output value. More...

Functions
mcp2221_error_code_t	mcp2221_gpio_write (mcp2221_t *dev, const mcp2221_gpio_write_t *wr)
	Update GPIO output values. More...
mcp2221_error_code_t	mcp2221_gpio_read (mcp2221_t *dev, int out_state[4])
	Read the current state of GP0 through GP3. More...
mcp2221_error_code_t	mcp2221_gpio_read_mask (mcp2221_t *dev, int out_state[4], uint8_t *out_valid_mask)
	Read GPIO state and report which GP pins are configured as GPIO. More...

Detailed Description

Direct GPIO input and output helpers.

Definition in file mcp2221_gpio.h.

Macro Definition Documentation

MCP2221_GPIO_KEEP

#define MCP2221_GPIO_KEEP   (-1)

Preserve the current GPIO output value.

Use this value in a member of mcp2221_gpio_write_t to leave the corresponding output unchanged.

Note

This sentinel is separate from MCP2221_CONFIG_KEEP, which belongs to the SRAM configuration API.

Definition at line 24 of file mcp2221_gpio.h.

Function Documentation

mcp2221_gpio_read()

mcp2221_error_code_t mcp2221_gpio_read	(	mcp2221_t *	dev,
		int	out_state[4]
	)

Read the current state of GP0 through GP3.

Each element of out_state corresponds to the same-numbered GP pin.

Parameters

[in]	dev	Open MCP2221 device handle.
[out]	out_state	Four-element array receiving pin states: -1 when the pin is not configured as GPIO 0 for logic low 1 for logic high

Returns

MCP2221_ERR_OK on success, MCP2221_ERR_INVALID for invalid arguments, or another mcp2221_error_code_t value on failure.

mcp2221_gpio_read_mask()

mcp2221_error_code_t mcp2221_gpio_read_mask	(	mcp2221_t *	dev,
		int	out_state[4],
		uint8_t *	out_valid_mask
	)

Read GPIO state and report which GP pins are configured as GPIO.

This mirrors the EasyMCP2221 GPIO-read semantics while providing an explicit validity mask in C.

Parameters

[in]	dev	Open MCP2221 device handle.
[out]	out_state	Four-element array receiving -1 for non-GPIO pins, otherwise 0 or 1 for the sampled logic level.
[out]	out_valid_mask	Receives a bit mask where bit 0 through bit 3 correspond to GP0 through GP3. A set bit means the corresponding pin is configured as GPIO.

Returns

MCP2221_ERR_OK on success, MCP2221_ERR_INVALID for invalid arguments, or another mcp2221_error_code_t value on failure.

See also

mcp2221_gpio_read()

mcp2221_gpio_write()

mcp2221_error_code_t mcp2221_gpio_write	(	mcp2221_t *	dev,
		const mcp2221_gpio_write_t *	wr
	)

Update GPIO output values.

Only members whose value is 0 or 1 are changed; members set to MCP2221_GPIO_KEEP preserve the current output value.

Parameters

[in]	dev	Open MCP2221 device handle.
[in]	wr	Per-pin output update request. Must not be NULL.

Returns

MCP2221_ERR_OK on success, MCP2221_ERR_INVALID for invalid arguments or member values, MCP2221_ERR_GPIO_MODE when a requested pin cannot be written as GPIO, MCP2221_ERR_PROTOCOL for an inconsistent device response, or another mcp2221_error_code_t value on failure.

Note

The library updates its cached GPIO output state for pins successfully accepted by the device. A return value of MCP2221_ERR_GPIO_MODE can therefore indicate partial success: other requested pins may already have been updated successfully.