Jack Berkhout / I2CEEBlockDevice

x

Dependents:   20180621_FT813

I2CEEBlockDevice.cpp@0:45d514e74be4, 2018-07-23 (annotated)

Committer:
JackB
Date:
Mon Jul 23 12:23:08 2018 +0000
Revision:
0:45d514e74be4
I2CEE

Who changed what in which revision?

UserRevisionLine numberNew contents of line
JackB 0:45d514e74be4 1 /* Simple access class for I2C EEPROM chips like Microchip 24LC
JackB 0:45d514e74be4 2 * Copyright (c) 2015 Robin Hourahane
JackB 0:45d514e74be4 3 *
JackB 0:45d514e74be4 4 * Licensed under the Apache License, Version 2.0 (the "License");
JackB 0:45d514e74be4 5 * you may not use this file except in compliance with the License.
JackB 0:45d514e74be4 6 * You may obtain a copy of the License at
JackB 0:45d514e74be4 7 *
JackB 0:45d514e74be4 8 * http://www.apache.org/licenses/LICENSE-2.0
JackB 0:45d514e74be4 9 *
JackB 0:45d514e74be4 10 * Unless required by applicable law or agreed to in writing, software
JackB 0:45d514e74be4 11 * distributed under the License is distributed on an "AS IS" BASIS,
JackB 0:45d514e74be4 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
JackB 0:45d514e74be4 13 * See the License for the specific language governing permissions and
JackB 0:45d514e74be4 14 * limitations under the License.
JackB 0:45d514e74be4 15 */
JackB 0:45d514e74be4 16 #include "I2CEEBlockDevice.h"
JackB 0:45d514e74be4 17
JackB 0:45d514e74be4 18 #define I2CEE_TIMEOUT 10000
JackB 0:45d514e74be4 19
JackB 0:45d514e74be4 20
JackB 0:45d514e74be4 21 I2CEEBlockDevice::I2CEEBlockDevice(
JackB 0:45d514e74be4 22 PinName sda, PinName scl, uint8_t addr,
JackB 0:45d514e74be4 23 bd_size_t size, bd_size_t block, int freq)
JackB 0:45d514e74be4 24 : _i2c(sda, scl), _i2c_addr(addr), _size(size), _block(block)
JackB 0:45d514e74be4 25 {
JackB 0:45d514e74be4 26 _i2c.frequency(freq);
JackB 0:45d514e74be4 27 }
JackB 0:45d514e74be4 28
JackB 0:45d514e74be4 29 int I2CEEBlockDevice::init()
JackB 0:45d514e74be4 30 {
JackB 0:45d514e74be4 31 return _sync();
JackB 0:45d514e74be4 32 }
JackB 0:45d514e74be4 33
JackB 0:45d514e74be4 34 int I2CEEBlockDevice::deinit()
JackB 0:45d514e74be4 35 {
JackB 0:45d514e74be4 36 return 0;
JackB 0:45d514e74be4 37 }
JackB 0:45d514e74be4 38
JackB 0:45d514e74be4 39 int I2CEEBlockDevice::read(void *buffer, bd_addr_t addr, bd_size_t size)
JackB 0:45d514e74be4 40 {
JackB 0:45d514e74be4 41 // Check the address and size fit onto the chip.
JackB 0:45d514e74be4 42 MBED_ASSERT(is_valid_read(addr, size));
JackB 0:45d514e74be4 43
JackB 0:45d514e74be4 44 _i2c.start();
JackB 0:45d514e74be4 45 if (!_i2c.write(_i2c_addr | 0) ||
JackB 0:45d514e74be4 46 !_i2c.write((char)(addr >> 8)) ||
JackB 0:45d514e74be4 47 !_i2c.write((char)(addr & 0xff))) {
JackB 0:45d514e74be4 48 return BD_ERROR_DEVICE_ERROR;
JackB 0:45d514e74be4 49 }
JackB 0:45d514e74be4 50 _i2c.stop();
JackB 0:45d514e74be4 51
JackB 0:45d514e74be4 52 if (_i2c.read(_i2c_addr, static_cast<char*>(buffer), size) < 0) {
JackB 0:45d514e74be4 53 return BD_ERROR_DEVICE_ERROR;
JackB 0:45d514e74be4 54 }
JackB 0:45d514e74be4 55
JackB 0:45d514e74be4 56 return 0;
JackB 0:45d514e74be4 57 }
JackB 0:45d514e74be4 58
JackB 0:45d514e74be4 59 int I2CEEBlockDevice::program(const void *buffer, bd_addr_t addr, bd_size_t size)
JackB 0:45d514e74be4 60 {
JackB 0:45d514e74be4 61 // Check the addr and size fit onto the chip.
JackB 0:45d514e74be4 62 MBED_ASSERT(is_valid_program(addr, size));
JackB 0:45d514e74be4 63
JackB 0:45d514e74be4 64 // While we have some more data to write.
JackB 0:45d514e74be4 65 while (size > 0) {
JackB 0:45d514e74be4 66 uint32_t off = addr % _block;
JackB 0:45d514e74be4 67 uint32_t chunk = (off + size < _block) ? size : (_block - off);
JackB 0:45d514e74be4 68
JackB 0:45d514e74be4 69 _i2c.start();
JackB 0:45d514e74be4 70 if (!_i2c.write(_i2c_addr | 0) ||
JackB 0:45d514e74be4 71 !_i2c.write((char)(addr >> 8)) ||
JackB 0:45d514e74be4 72 !_i2c.write((char)(addr & 0xff))) {
JackB 0:45d514e74be4 73 return BD_ERROR_DEVICE_ERROR;
JackB 0:45d514e74be4 74 }
JackB 0:45d514e74be4 75
JackB 0:45d514e74be4 76 for (unsigned i = 0; i < chunk; i++) {
JackB 0:45d514e74be4 77 _i2c.write(static_cast<const char*>(buffer)[i]);
JackB 0:45d514e74be4 78 }
JackB 0:45d514e74be4 79 _i2c.stop();
JackB 0:45d514e74be4 80
JackB 0:45d514e74be4 81 int err = _sync();
JackB 0:45d514e74be4 82 if (err) {
JackB 0:45d514e74be4 83 return err;
JackB 0:45d514e74be4 84 }
JackB 0:45d514e74be4 85
JackB 0:45d514e74be4 86 addr += chunk;
JackB 0:45d514e74be4 87 size -= chunk;
JackB 0:45d514e74be4 88 buffer = static_cast<const char*>(buffer) + chunk;
JackB 0:45d514e74be4 89 }
JackB 0:45d514e74be4 90
JackB 0:45d514e74be4 91 return 0;
JackB 0:45d514e74be4 92 }
JackB 0:45d514e74be4 93
JackB 0:45d514e74be4 94 int I2CEEBlockDevice::erase(bd_addr_t addr, bd_size_t size)
JackB 0:45d514e74be4 95 {
JackB 0:45d514e74be4 96 // No erase needed
JackB 0:45d514e74be4 97 return 0;
JackB 0:45d514e74be4 98 }
JackB 0:45d514e74be4 99
JackB 0:45d514e74be4 100 int I2CEEBlockDevice::_sync()
JackB 0:45d514e74be4 101 {
JackB 0:45d514e74be4 102 // The chip doesn't ACK while writing to the actual EEPROM
JackB 0:45d514e74be4 103 // so loop trying to do a zero byte write until it is ACKed
JackB 0:45d514e74be4 104 // by the chip.
JackB 0:45d514e74be4 105 for (int i = 0; i < I2CEE_TIMEOUT; i++) {
JackB 0:45d514e74be4 106 if (_i2c.write(_i2c_addr | 0, 0, 0) < 1) {
JackB 0:45d514e74be4 107 return 0;
JackB 0:45d514e74be4 108 }
JackB 0:45d514e74be4 109
JackB 0:45d514e74be4 110 wait_ms(1);
JackB 0:45d514e74be4 111 }
JackB 0:45d514e74be4 112
JackB 0:45d514e74be4 113 return BD_ERROR_DEVICE_ERROR;
JackB 0:45d514e74be4 114 }
JackB 0:45d514e74be4 115
JackB 0:45d514e74be4 116 bd_size_t I2CEEBlockDevice::get_read_size() const
JackB 0:45d514e74be4 117 {
JackB 0:45d514e74be4 118 return 1;
JackB 0:45d514e74be4 119 }
JackB 0:45d514e74be4 120
JackB 0:45d514e74be4 121 bd_size_t I2CEEBlockDevice::get_program_size() const
JackB 0:45d514e74be4 122 {
JackB 0:45d514e74be4 123 return 1;
JackB 0:45d514e74be4 124 }
JackB 0:45d514e74be4 125
JackB 0:45d514e74be4 126 bd_size_t I2CEEBlockDevice::get_erase_size() const
JackB 0:45d514e74be4 127 {
JackB 0:45d514e74be4 128 return 1;
JackB 0:45d514e74be4 129 }
JackB 0:45d514e74be4 130
JackB 0:45d514e74be4 131 bd_size_t I2CEEBlockDevice::size() const
JackB 0:45d514e74be4 132 {
JackB 0:45d514e74be4 133 return _size;
JackB 0:45d514e74be4 134 }