NVMEM

Interfaces for NVMEM cells. More...

Files
file	nvmem.h
	Main header file for NVMEM API.

Data Structures
struct	nvmem_cell
	Non-Volatile Memory cell representation. More...

Macros
#define	NVMEM_CELL_INIT(node_id)
	Static initializer for a struct nvmem_cell.
#define	NVMEM_CELL_GET_BY_NAME(node_id, name)
	Static initializer for a struct nvmem_cell.
#define	NVMEM_CELL_INST_GET_BY_NAME(inst, name)
	Static initializer for a struct nvmem_cell from a DT_DRV_COMPAT instance.
#define	NVMEM_CELL_GET_BY_NAME_OR(node_id, name, default_value)
	Like NVMEM_CELL_GET_BY_NAME(), with a fallback to a default value.
#define	NVMEM_CELL_INST_GET_BY_NAME_OR(inst, name, default_value)
	Like NVMEM_CELL_INST_GET_BY_NAME(), with a fallback to a default value.
#define	NVMEM_CELL_GET_BY_IDX(node_id, idx)
	Static initializer for a struct nvmem_cell.
#define	NVMEM_CELL_INST_GET_BY_IDX(inst, idx)
	Static initializer for a struct nvmem_cell from a DT_DRV_COMPAT instance.
#define	NVMEM_CELL_GET_BY_IDX_OR(node_id, idx, default_value)
	Like NVMEM_CELL_GET_BY_IDX(), with a fallback to a default value.
#define	NVMEM_CELL_INST_GET_BY_IDX_OR(inst, idx, default_value)
	Like NVMEM_CELL_INST_GET_BY_IDX(), with a fallback to a default value.

Functions
int	nvmem_cell_read (const struct nvmem_cell *cell, void *data, off_t off, size_t len)
	Read data from an NVMEM cell.
int	nvmem_cell_write (const struct nvmem_cell *cell, const void *data, off_t off, size_t len)
	Write data to an NVMEM cell.
static bool	nvmem_cell_is_ready (const struct nvmem_cell *cell)
	Validate that the NVMEM cell is ready.

Detailed Description

Interfaces for NVMEM cells.

Since

4.3

Version

0.1.0

Macro Definition Documentation

NVMEM_CELL_GET_BY_IDX

#define NVMEM_CELL_GET_BY_IDX	(		node_id,
			idx )

#include <zephyr/nvmem.h>

Value:

NVMEM_CELL_INIT(DT_NVMEM_CELL_BY_IDX(node_id, idx))

Static initializer for a struct nvmem_cell.

This returns a static initializer for a struct nvmem_cell given a devicetree node identifier and an index.

Example devicetree fragment:

mac_eeprom: mac_eeprom@2 {
   nvmem-layout {
           compatible = "fixed-layout";
           #address-cells = <1>;
           #size-cells = <1>;
 
           mac_address: mac_address@fa {
                   reg = <0xfa 0x06>;
                   #nvmem-cell-cells = <0>;
           };
   };
};
 
eth: ethernet {
   nvmem-cells = <&mac_address>;
   nvmem-cell-names = "mac-address";
};

Example usage:

const struct nvmem_cell cell =
   NVMEM_CELL_GET_BY_IDX(DT_NODELABEL(eth), 0);
 
// Initializes 'cell' to:
// {
// .dev = DEVICE_DT_GET(DT_NODELABEL(mac_eeprom)),
// .offset = 0xfa,
// .size = 6,
// .read_only = false,
// }

Parameters

node_id	Devicetree node identifier.
idx	Logical index into 'nvmem-cells' property.

Returns

Static initializer for a struct nvmem_cell for the property.

See also

NVMEM_CELL_INST_GET_BY_IDX

NVMEM_CELL_GET_BY_IDX_OR

#define NVMEM_CELL_GET_BY_IDX_OR	(		node_id,
			idx,
			default_value )

#include <zephyr/nvmem.h>

Value:

        COND_CODE_1(DT_NODE_HAS_PROP(node_id, nvmem_cells),                                        \
                    (NVMEM_CELL_GET_BY_IDX(node_id, idx)),                                         \
                    (default_value))

Like NVMEM_CELL_GET_BY_IDX(), with a fallback to a default value.

If the devicetree node identifier 'node_id' refers to a node with a property 'nvmem-cells', this expands to NVMEM_CELL_GET_BY_IDX(node_id, idx). The default_value parameter is not expanded in this case. Otherwise, this expands to default_value.

Parameters

node_id	Devicetree node identifier.
idx	Logical index into 'nvmem-cells' property.
default_value	Fallback value to expand to.

Returns

Static initializer for a struct nvmem_cell for the property, or default_value if the node or property do not exist.

See also

NVMEM_CELL_INST_GET_BY_IDX_OR

NVMEM_CELL_GET_BY_NAME

#define NVMEM_CELL_GET_BY_NAME	(		node_id,
			name )

#include <zephyr/nvmem.h>

Value:

NVMEM_CELL_INIT(DT_NVMEM_CELL_BY_NAME(node_id, name))

Static initializer for a struct nvmem_cell.

This returns a static initializer for a struct nvmem_cell given a devicetree node identifier and a name.

Example devicetree fragment:

mac_eeprom: mac_eeprom@2 {
   nvmem-layout {
           compatible = "fixed-layout";
           #address-cells = <1>;
           #size-cells = <1>;
 
           mac_address: mac_address@fa {
                   reg = <0xfa 0x06>;
                   #nvmem-cell-cells = <0>;
           };
   };
};
 
eth: ethernet {
   nvmem-cells = <&mac_address>;
   nvmem-cell-names = "mac-address";
};

Example usage:

const struct nvmem_cell cell =
   NVMEM_CELL_GET_BY_NAME(DT_NODELABEL(eth), mac_address);
 
// Initializes 'cell' to:
// {
// .dev = DEVICE_DT_GET(DT_NODELABEL(mac_eeprom)),
// .offset = 0xfa,
// .size = 6,
// .read_only = false,
// }

Parameters

node_id	Devicetree node identifier.
name	Lowercase-and-underscores name of an nvmem-cells element as defined by the node's nvmem-cell-names property.

Returns

Static initializer for a struct nvmem_cell for the property.

See also

NVMEM_CELL_INST_GET_BY_NAME

NVMEM_CELL_GET_BY_NAME_OR

#define NVMEM_CELL_GET_BY_NAME_OR	(		node_id,
			name,
			default_value )

#include <zephyr/nvmem.h>

Value:

        COND_CODE_1(DT_NODE_HAS_PROP(node_id, nvmem_cells),                                        \
                    (NVMEM_CELL_GET_BY_NAME(node_id, name)),                                       \
                    (default_value))

Like NVMEM_CELL_GET_BY_NAME(), with a fallback to a default value.

If the devicetree node identifier 'node_id' refers to a node with a property 'nvmem-cells', this expands to NVMEM_CELL_GET_BY_NAME(node_id, name). The default_value parameter is not expanded in this case. Otherwise, this expands to default_value.

Parameters

node_id	Devicetree node identifier.
name	Lowercase-and-underscores name of an nvmem-cells element as defined by the node's nvmem-cell-names property.
default_value	Fallback value to expand to.

Returns

Static initializer for a struct nvmem_cell for the property, or default_value if the node or property do not exist.

See also

NVMEM_CELL_INST_GET_BY_NAME_OR

NVMEM_CELL_INIT

#define NVMEM_CELL_INIT

(

node_id

)

#include <zephyr/nvmem.h>

Value:

        {                                                                                          \
                .dev = DEVICE_DT_GET(DT_MTD_FROM_NVMEM_CELL(node_id)),                             \
                .offset = DT_REG_ADDR(node_id),                                                    \
                .size = DT_REG_SIZE(node_id),                                                      \
                .read_only = DT_PROP(node_id, read_only),                                          \
        }

Static initializer for a struct nvmem_cell.

This returns a static initializer for a struct nvmem_cell given a devicetree node identifier.

Note

This is a helper macro for other NVMEM_CELL_GET macros to initialize the nvmem_cell struct.

Example devicetree fragment:

mac_eeprom: mac_eeprom@2 {
   nvmem-layout {
           compatible = "fixed-layout";
           #address-cells = <1>;
           #size-cells = <1>;
 
           mac_address: mac_address@fa {
                   reg = <0xfa 0x06>;
                   #nvmem-cell-cells = <0>;
           };
   };
};

Example usage:

const struct nvmem_cell cell = NVMEM_CELL_INIT(DT_NODELABEL(mac_address));
 
// Initializes 'cell' to:
// {
// .dev = DEVICE_DT_GET(DT_NODELABEL(mac_eeprom)),
// .offset = 0xfa,
// .size = 6,
// .read_only = false,
// }

Parameters

node_id

Devicetree node identifier.

Returns

Static initializer for a struct nvmem_cell

NVMEM_CELL_INST_GET_BY_IDX

#define NVMEM_CELL_INST_GET_BY_IDX	(		inst,
			idx )

#include <zephyr/nvmem.h>

Value:

NVMEM_CELL_GET_BY_IDX(DT_DRV_INST(inst), idx)

Static initializer for a struct nvmem_cell from a DT_DRV_COMPAT instance.

Parameters

inst	DT_DRV_COMPAT instance number
idx	Logical index into 'nvmem-cells' property.

Returns

Static initializer for a struct nvmem_cell for the property.

See also

NVMEM_CELL_GET_BY_IDX

NVMEM_CELL_INST_GET_BY_IDX_OR

#define NVMEM_CELL_INST_GET_BY_IDX_OR	(		inst,
			idx,
			default_value )

#include <zephyr/nvmem.h>

Value:

        NVMEM_CELL_GET_BY_IDX_OR(DT_DRV_INST(inst), idx, default_value)

Like NVMEM_CELL_INST_GET_BY_IDX(), with a fallback to a default value.

Parameters

inst	DT_DRV_COMPAT instance number
idx	Logical index into 'nvmem-cells' property.
default_value	Fallback value to expand to.

Returns

Static initializer for a struct nvmem_cell for the property, or default_value if the node or property do not exist.

See also

NVMEM_CELL_GET_BY_IDX_OR

NVMEM_CELL_INST_GET_BY_NAME

#define NVMEM_CELL_INST_GET_BY_NAME	(		inst,
			name )

#include <zephyr/nvmem.h>

Value:

NVMEM_CELL_GET_BY_NAME(DT_DRV_INST(inst), name)

Static initializer for a struct nvmem_cell from a DT_DRV_COMPAT instance.

Parameters

inst	DT_DRV_COMPAT instance number
name	Lowercase-and-underscores name of an nvmem-cells element as defined by the node's nvmem-cell-names property.

Returns

Static initializer for a struct nvmem_cell for the property.

See also

NVMEM_CELL_GET_BY_NAME

NVMEM_CELL_INST_GET_BY_NAME_OR

#define NVMEM_CELL_INST_GET_BY_NAME_OR	(		inst,
			name,
			default_value )

#include <zephyr/nvmem.h>

Value:

        NVMEM_CELL_GET_BY_NAME_OR(DT_DRV_INST(inst), name, default_value)

Like NVMEM_CELL_INST_GET_BY_NAME(), with a fallback to a default value.

Parameters

inst	DT_DRV_COMPAT instance number
name	Lowercase-and-underscores name of an nvmem-cells element as defined by the node's nvmem-cell-names property.
default_value	Fallback value to expand to.

Returns

Static initializer for a struct nvmem_cell for the property, or default_value if the node or property do not exist.

See also

NVMEM_CELL_GET_BY_NAME_OR

Function Documentation

nvmem_cell_is_ready()

bool nvmem_cell_is_ready ( const struct nvmem_cell * cell )

inlinestatic

#include <zephyr/nvmem.h>

Validate that the NVMEM cell is ready.

Parameters

cell	The NVMEM cell.

Returns

true if the NVMEM cell is ready for use and false otherwise.

nvmem_cell_read()

int nvmem_cell_read	(	const struct nvmem_cell *	cell,
		void *	data,
		off_t	off,
		size_t	len )

#include <zephyr/nvmem.h>

Read data from an NVMEM cell.

Parameters

cell	The NVMEM cell.
data	Buffer to store read data.
off	The offset to start reading from.
len	Number of bytes to read.

Attention

Available only when the following Kconfig option is enabled: CONFIG_NVMEM.

Returns

0 on success, negative errno code on failure.

nvmem_cell_write()

int nvmem_cell_write	(	const struct nvmem_cell *	cell,
		const void *	data,
		off_t	off,
		size_t	len )

#include <zephyr/nvmem.h>

Write data to an NVMEM cell.

Parameters

cell	The NVMEM cell.
data	Buffer with data to write.
off	The offset to start writing to.
len	Number of bytes to write.

Attention

Available only when the following Kconfig option is enabled: CONFIG_NVMEM.

Returns

0 on success, negative errno code on failure.