Retained memory driver interface

Retained memory driver interface. More...

Data Structures
struct	retained_mem_driver_api
	Retained memory driver API API which can be used by a device to store data in a retained memory area. Retained memory is memory that is retained while the device is powered but is lost when power to the device is lost (note that low power modes in some devices may clear the data also). This may be in a non-initialised RAM region, or in specific registers, but is not reset when a different application begins execution or the device is rebooted (without power loss). It must support byte-level reading and writing without a need to erase data before writing. More...

Typedefs
typedef ssize_t(*	retained_mem_size_api) (const struct device *dev)
	Callback API to get size of retained memory area. See retained_mem_size() for argument description.
typedef int(*	retained_mem_read_api) (const struct device *dev, off_t offset, uint8_t *buffer, size_t size)
	Callback API to read from retained memory area. See retained_mem_read() for argument description.
typedef int(*	retained_mem_write_api) (const struct device *dev, off_t offset, const uint8_t *buffer, size_t size)
	Callback API to write to retained memory area. See retained_mem_write() for argument description.
typedef int(*	retained_mem_clear_api) (const struct device *dev)
	Callback API to clear retained memory area (reset all data to 0x00). See retained_mem_clear() for argument description.

Functions
ssize_t	retained_mem_size (const struct device *dev)
	Returns the size of the retained memory area.
int	retained_mem_read (const struct device *dev, off_t offset, uint8_t *buffer, size_t size)
	Reads data from the Retained memory area.
int	retained_mem_write (const struct device *dev, off_t offset, const uint8_t *buffer, size_t size)
	Writes data to the Retained memory area - underlying data does not need to be cleared prior to writing.
int	retained_mem_clear (const struct device *dev)
	Clears data in the retained memory area by setting it to 0x00.

Detailed Description

Retained memory driver interface.

Typedef Documentation

retained_mem_clear_api

retained_mem_clear_api

#include <zephyr/drivers/retained_mem.h>

Callback API to clear retained memory area (reset all data to 0x00). See retained_mem_clear() for argument description.

retained_mem_read_api

retained_mem_read_api

#include <zephyr/drivers/retained_mem.h>

Callback API to read from retained memory area. See retained_mem_read() for argument description.

retained_mem_size_api

retained_mem_size_api

#include <zephyr/drivers/retained_mem.h>

Callback API to get size of retained memory area. See retained_mem_size() for argument description.

retained_mem_write_api

retained_mem_write_api

#include <zephyr/drivers/retained_mem.h>

Callback API to write to retained memory area. See retained_mem_write() for argument description.

Function Documentation

retained_mem_clear()

int retained_mem_clear

(

const struct device *

dev

)

#include <zephyr/drivers/retained_mem.h>

Clears data in the retained memory area by setting it to 0x00.

Parameters

dev	Retained memory device to use.

Return values

0	on success else negative errno code.

retained_mem_read()

int retained_mem_read	(	const struct device *	dev,
		off_t	offset,
		uint8_t *	buffer,
		size_t	size
	)

#include <zephyr/drivers/retained_mem.h>

Reads data from the Retained memory area.

Parameters

dev	Retained memory device to use.
offset	Offset to read data from.
buffer	Buffer to store read data in.
size	Size of data to read.

Return values

0	on success else negative errno code.

retained_mem_size()

ssize_t retained_mem_size

(

const struct device *

dev

)

#include <zephyr/drivers/retained_mem.h>

Returns the size of the retained memory area.

Parameters

dev	Retained memory device to use.

Return values

Positive

value indicating size in bytes on success, else negative errno code.

retained_mem_write()

int retained_mem_write	(	const struct device *	dev,
		off_t	offset,
		const uint8_t *	buffer,
		size_t	size
	)

#include <zephyr/drivers/retained_mem.h>

Writes data to the Retained memory area - underlying data does not need to be cleared prior to writing.

Parameters

dev	Retained memory device to use.
offset	Offset to write data to.
buffer	Data to write.
size	Size of data to be written.

Return values

0	on success else negative errno code.