mcp2221_flash_info.h File Reference

Aggregate flash-information and configuration-save helpers. More...

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

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Classes
struct	mcp2221_flash_info_t
	Snapshot of the public MCP2221 flash-information sections. More...

Functions
mcp2221_error_code_t	mcp2221_flash_read_info (mcp2221_t *dev, mcp2221_flash_info_t *info)
	Read all public flash-information sections. More...
mcp2221_error_code_t	mcp2221_flash_get_usb_serial (mcp2221_t *dev, char *serial, size_t serial_size)
	Read the persistent USB serial number from flash. More...
mcp2221_error_code_t	mcp2221_flash_get_factory_serial (mcp2221_t *dev, char *serial, size_t serial_size)
	Read the read-only factory/chip serial number from flash. More...
mcp2221_error_code_t	mcp2221_flash_save_config (mcp2221_t *dev)
	Save the current runtime configuration to persistent flash. More...

Detailed Description

Aggregate flash-information and configuration-save helpers.

Definition in file mcp2221_flash_info.h.

Function Documentation

mcp2221_flash_get_factory_serial()

mcp2221_error_code_t mcp2221_flash_get_factory_serial	(	mcp2221_t *	dev,
		char *	serial,
		size_t	serial_size
	)

Read the read-only factory/chip serial number from flash.

Reads only the factory/chip serial-number flash section.

Parameters

[in]	dev	Open MCP2221 device handle.
[out]	serial	Receives the null-terminated factory serial on success.
[in]	serial_size	Size of serial in bytes, including the terminator.

Returns

MCP2221_ERR_OK on success, MCP2221_ERR_INVALID for invalid arguments or an output buffer too small for the complete serial, MCP2221_ERR_PROTOCOL for malformed length metadata, or another error returned while reading flash. The output is unchanged on failure.

mcp2221_flash_get_usb_serial()

mcp2221_error_code_t mcp2221_flash_get_usb_serial	(	mcp2221_t *	dev,
		char *	serial,
		size_t	serial_size
	)

Read the persistent USB serial number from flash.

Reads only the USB serial-number flash section and decodes its validated UTF-16LE descriptor payload to UTF-8.

Parameters

[in]	dev	Open MCP2221 device handle.
[out]	serial	Receives the null-terminated UTF-8 serial on success.
[in]	serial_size	Size of serial in bytes, including the terminator.

Returns

MCP2221_ERR_OK on success, MCP2221_ERR_INVALID for invalid arguments or an output buffer too small for the complete serial, MCP2221_ERR_PROTOCOL for malformed descriptor metadata, or another error returned while reading flash. The output is unchanged on failure.

mcp2221_flash_read_info()

mcp2221_error_code_t mcp2221_flash_read_info	(	mcp2221_t *	dev,
		mcp2221_flash_info_t *	info
	)

Read all public flash-information sections.

The output structure is cleared first, then the chip settings, GP settings, USB manufacturer, USB product, USB serial, and factory/chip serial sections are read. USB descriptor metadata is validated before USB-style wide-character structures are decoded to UTF-8 on a best-effort basis.

Parameters

[in]	dev	Open MCP2221 device handle.
[out]	info	Receives raw flash sections and decoded strings.

Returns

MCP2221_ERR_OK on success, MCP2221_ERR_INVALID for invalid arguments, MCP2221_ERR_PROTOCOL for malformed string-descriptor metadata, or another error returned while reading flash.

mcp2221_flash_save_config()

mcp2221_error_code_t mcp2221_flash_save_config

(

mcp2221_t *

dev

)

Save the current runtime configuration to persistent flash.

The function updates the persistent chip-settings and GP-settings sections from the current device SRAM state. GPIO values are taken from the library's cached GPIO state when available so that changes made through the GPIO API are retained.

Enumeration-time USB power attributes and requested-current values remain unchanged unless the corresponding USB setter has staged an explicit update.

Parameters

[in]

dev

Open MCP2221 device handle.

Returns

MCP2221_ERR_OK on success, MCP2221_ERR_INVALID for an invalid device handle or internal state, MCP2221_ERR_PROTOCOL for malformed GET SRAM length metadata, MCP2221_ERR_FLASH_PASSWD when chip protection prevents a safe configuration save, or another mcp2221_error_code_t value on failure.

Warning

This function performs persistent flash writes and is not atomic. The chip-settings section is written before the GP-settings section, so a later failure can leave the earlier section already persisted. Staged USB settings are cleared only after both writes succeed; they remain staged if the save fails.