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atmel,at24 (on i2c bus)

Vendor: Atmel Corporation

Note

An implementation of a driver matching this compatible is available in drivers/eeprom/eeprom_at2x_emul.c.

Description

I2C EEPROMs compatible with Atmel's AT24 family

There are multiple vendors manufacturing I2C EEPROMs compatible with the programming model of the
Atmel AT24.

Examples of compatible EEPROM families:
- Microchip AT24xxx
- ST M24xxx

Each of these can be represented by a set of common parameters (EEPROM size, page size, address
width, and timeout) available from the datasheet of the specific EEPROM. The compatible string for
these can list the specific EEPROM vendor and model along with the vendor EEPROM family as long as
the least-specific compatible entry is "atmel,at24".

Example devicetree node describing a ST M24M01 EEPROM on the i2c0 bus:

  &i2c0 {
    status = "okay";
    clock-frequency = <I2C_BITRATE_FAST>;

    eeprom@56 {
      compatible = "st,m24m01", "st,m24xxx", "atmel,at24";
      reg = <0x56>;
      size = <DT_SIZE_K(128)>;
      pagesize = <256>;
      address-width = <16>;
      timeout = <5>;
   };
 };

Properties

Properties not inherited from the base binding file.

Name

Type

Details

size

int

 
Total EEPROM size in bytes

This property is required.

pagesize

int

 
EEPROM page size in bytes

This property is required.

address-width

int

 
EEPROM address width in bits

This property is required.

timeout

int

 
EEPROM write cycle timeout in milliseconds

This property is required.

wp-gpios

phandle-array

 
GPIO to which the write-protect pin of the chip is connected.

The device will interpret this signal as active-low.

read-only

boolean

 
Disable writes to the EEPROM

supply-gpios

phandle-array

 
GPIO specifier that controls power to the device.

This property should be provided when the device has a dedicated
switch that controls power to the device.  The supply state is
entirely the responsibility of the device driver.

Contrast with vin-supply.

vin-supply

phandle

 
Reference to the regulator that controls power to the device.
The referenced devicetree node must have a regulator compatible.

This property should be provided when device power is supplied
by a shared regulator.  The supply state is dependent on the
request status of all devices fed by the regulator.

Contrast with supply-gpios.  If both properties are provided
then the regulator must be requested before the supply GPIOS is
set to an active state, and the supply GPIOS must be set to an
inactive state before releasing the regulator.