mirror of https://github.com/ARMmbed/mbed-os.git
87 lines
2.5 KiB
C++
87 lines
2.5 KiB
C++
/*
|
|
* Copyright (c) 2016-2016 ARM Limited. All rights reserved.
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
* Licensed under the Apache License, Version 2.0 (the License); you may
|
|
* not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
#include "at24mac.h"
|
|
|
|
#if DEVICE_I2C
|
|
|
|
/* Device addressing */
|
|
#define AT24MAC_EEPROM_ADDRESS (0x0A<<4)
|
|
#define AT24MAC_RW_PROTECT_ADDRESS (0x06<<4)
|
|
#define AT24MAC_SERIAL_ADDRESS (0x0B<<4)
|
|
|
|
/* Known memory blocks */
|
|
#define AT24MAC_SERIAL_OFFSET (0x80)
|
|
#define AT24MAC_EUI64_OFFSET (0x98)
|
|
#define AT24MAC_EUI48_OFFSET (0x9A)
|
|
|
|
#define SERIAL_LEN 16
|
|
#define EUI64_LEN 8
|
|
#define EUI48_LEN 6
|
|
|
|
AT24Mac::I2CReset::I2CReset(PinName sda, PinName scl)
|
|
{
|
|
mbed::DigitalInOut pin_sda(sda, PIN_OUTPUT, PullUp, 1);
|
|
mbed::DigitalInOut pin_scl(scl, PIN_OUTPUT, PullUp, 0);
|
|
//generate 9 clocks for worst-case scenario
|
|
for (int i = 0; i < 10; ++i) {
|
|
pin_scl = 1;
|
|
wait_us(5);
|
|
pin_scl = 0;
|
|
wait_us(5);
|
|
}
|
|
//generate a STOP condition
|
|
pin_sda = 0;
|
|
wait_us(5);
|
|
pin_scl = 1;
|
|
wait_us(5);
|
|
pin_sda = 1;
|
|
wait_us(5);
|
|
}
|
|
|
|
/*I2C needs to be reset before constructing the I2C object (in case I2C is stuck)
|
|
because they use the same pins, therefore i2c_reset has to be before _i2c
|
|
in the initializer list*/
|
|
AT24Mac::AT24Mac(PinName sda, PinName scl) : i2c_reset(sda, scl), _i2c(sda, scl)
|
|
{
|
|
// Do nothing
|
|
}
|
|
|
|
int AT24Mac::read_serial(void *buf)
|
|
{
|
|
char offset = AT24MAC_SERIAL_OFFSET;
|
|
if (_i2c.write(AT24MAC_SERIAL_ADDRESS, &offset, 1, true))
|
|
return -1; //No ACK
|
|
return _i2c.read(AT24MAC_SERIAL_ADDRESS, (char*)buf, SERIAL_LEN);
|
|
}
|
|
|
|
int AT24Mac::read_eui64(void *buf)
|
|
{
|
|
char offset = AT24MAC_EUI64_OFFSET;
|
|
if (_i2c.write(AT24MAC_SERIAL_ADDRESS, &offset, 1, true))
|
|
return -1; //No ACK
|
|
return _i2c.read(AT24MAC_SERIAL_ADDRESS, (char*)buf, EUI64_LEN);
|
|
}
|
|
|
|
int AT24Mac::read_eui48(void *buf)
|
|
{
|
|
char offset = AT24MAC_EUI48_OFFSET;
|
|
if (_i2c.write(AT24MAC_SERIAL_ADDRESS, &offset, 1, true))
|
|
return -1; //No ACK
|
|
return _i2c.read(AT24MAC_SERIAL_ADDRESS, (char*)buf, EUI48_LEN);
|
|
}
|
|
|
|
#endif /* DEVICE_I2C */
|