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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?
User | Revision | Line number | New 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 | } |