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| 1 | +/* Simple access class for I2C EEPROM chips like Microchip 24LC |
| 2 | + * Copyright (c) 2015 Robin Hourahane |
| 3 | + * |
| 4 | + * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | + * you may not use this file except in compliance with the License. |
| 6 | + * You may obtain a copy of the License at |
| 7 | + * |
| 8 | + * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | + * |
| 10 | + * Unless required by applicable law or agreed to in writing, software |
| 11 | + * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | + * See the License for the specific language governing permissions and |
| 14 | + * limitations under the License. |
| 15 | + */ |
| 16 | +#ifndef MBED_I2CEEPROM_BLOCK_DEVICE_H |
| 17 | +#define MBED_I2CEEPROM_BLOCK_DEVICE_H |
| 18 | + |
| 19 | +#include "BlockDevice.h" |
| 20 | +#include "I2C.h" |
| 21 | + |
| 22 | +/** BlockDevice for I2C based flash device such as |
| 23 | + * Microchip's 24LC or ATMEL's AT24C ranges |
| 24 | + * |
| 25 | + * @code |
| 26 | + * // Here's an example using a 24LC256 on a GR PEACH |
| 27 | + * #include "mbed.h" |
| 28 | + * #include "I2CEEBlockDevice.h" |
| 29 | + * |
| 30 | + * // Create EEPROM device on I2C bus with 32kbytes of memory |
| 31 | + * I2CEEBlockDevice i2cee(D14, D15, 0xa0, 32*1024); |
| 32 | + * |
| 33 | + * int main() { |
| 34 | + * printf("i2cee test\n"); |
| 35 | + * |
| 36 | + * // Initialize the device and print the memory layout |
| 37 | + * i2cee.init(); |
| 38 | + * printf("i2cee size: %llu\n", i2cee.size()); |
| 39 | + * printf("i2cee read size: %llu\n", i2cee.get_read_size()); |
| 40 | + * printf("i2cee program size: %llu\n", i2cee.get_program_size()); |
| 41 | + * printf("i2cee erase size: %llu\n", i2cee.get_erase_size()); |
| 42 | + * |
| 43 | + * // Write "Hello World!" to the first block |
| 44 | + * char *buffer = (char*)malloc(i2cee.get_erase_size()); |
| 45 | + * sprintf(buffer, "Hello World!\n"); |
| 46 | + * i2cee.erase(0, i2cee.get_erase_size()); |
| 47 | + * i2cee.program(buffer, 0, i2cee.get_erase_size()); |
| 48 | + * |
| 49 | + * // Read back what was stored |
| 50 | + * i2cee.read(buffer, 0, i2cee.get_erase_size()); |
| 51 | + * printf("%s", buffer); |
| 52 | + * |
| 53 | + * // Deinitialize the device |
| 54 | + * i2cee.deinit(); |
| 55 | + * } |
| 56 | + * @endcode |
| 57 | + */ |
| 58 | +class I2CEEBlockDevice : public BlockDevice { |
| 59 | +public: |
| 60 | + /** Constructor to create an I2CEEBlockDevice on I2C pins |
| 61 | + * |
| 62 | + * @param sda The pin name for the sda line of the I2C bus. |
| 63 | + * @param scl The pin name for the scl line of the I2C bus. |
| 64 | + * @param addr The 8bit I2C address of the chip, common range 0xa0 - 0xae. |
| 65 | + * @param size The size of the device in bytes |
| 66 | + * @param block The page size of the device in bytes, defaults to 32bytes |
| 67 | + * @param freq The frequency of the I2C bus, defaults to 400K. |
| 68 | + */ |
| 69 | + I2CEEBlockDevice( |
| 70 | + PinName sda, PinName scl, uint8_t address, |
| 71 | + bd_size_t size, bd_size_t block = 32, |
| 72 | + int bus_speed = 400000); |
| 73 | + |
| 74 | + /** Constructor to create an I2CEEBlockDevice on I2C pins |
| 75 | + * |
| 76 | + * @param i2c The I2C instance pointer |
| 77 | + * @param addr The 8bit I2C address of the chip, common range 0xa0 - 0xae. |
| 78 | + * @param size The size of the device in bytes |
| 79 | + * @param block The page size of the device in bytes, defaults to 32bytes |
| 80 | + * @param freq The frequency of the I2C bus, defaults to 400K. |
| 81 | + */ |
| 82 | + I2CEEBlockDevice( |
| 83 | + mbed::I2C *i2c_obj, uint8_t address, |
| 84 | + bd_size_t size, bd_size_t block = 32); |
| 85 | + |
| 86 | + /** Destructor of I2CEEBlockDevice |
| 87 | + */ |
| 88 | + |
| 89 | + virtual ~I2CEEBlockDevice(); |
| 90 | + |
| 91 | + /** Initialize a block device |
| 92 | + * |
| 93 | + * @return 0 on success or a negative error code on failure |
| 94 | + */ |
| 95 | + virtual int init(); |
| 96 | + |
| 97 | + /** Deinitialize a block device |
| 98 | + * |
| 99 | + * @return 0 on success or a negative error code on failure |
| 100 | + */ |
| 101 | + virtual int deinit(); |
| 102 | + |
| 103 | + /** Read blocks from a block device |
| 104 | + * |
| 105 | + * @param buffer Buffer to write blocks to |
| 106 | + * @param addr Address of block to begin reading from |
| 107 | + * @param size Size to read in bytes, must be a multiple of read block size |
| 108 | + * @return 0 on success, negative error code on failure |
| 109 | + */ |
| 110 | + virtual int read(void *buffer, bd_addr_t addr, bd_size_t size); |
| 111 | + |
| 112 | + /** Program blocks to a block device |
| 113 | + * |
| 114 | + * The blocks must have been erased prior to being programmed |
| 115 | + * |
| 116 | + * @param buffer Buffer of data to write to blocks |
| 117 | + * @param addr Address of block to begin writing to |
| 118 | + * @param size Size to write in bytes, must be a multiple of program block size |
| 119 | + * @return 0 on success, negative error code on failure |
| 120 | + */ |
| 121 | + virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size); |
| 122 | + |
| 123 | + /** Erase blocks on a block device |
| 124 | + * |
| 125 | + * The state of an erased block is undefined until it has been programmed |
| 126 | + * |
| 127 | + * @param addr Address of block to begin erasing |
| 128 | + * @param size Size to erase in bytes, must be a multiple of erase block size |
| 129 | + * @return 0 on success, negative error code on failure |
| 130 | + */ |
| 131 | + virtual int erase(bd_addr_t addr, bd_size_t size); |
| 132 | + |
| 133 | + /** Get the size of a readable block |
| 134 | + * |
| 135 | + * @return Size of a readable block in bytes |
| 136 | + */ |
| 137 | + virtual bd_size_t get_read_size() const; |
| 138 | + |
| 139 | + /** Get the size of a programable block |
| 140 | + * |
| 141 | + * @return Size of a programable block in bytes |
| 142 | + * @note Must be a multiple of the read size |
| 143 | + */ |
| 144 | + virtual bd_size_t get_program_size() const; |
| 145 | + |
| 146 | + /** Get the size of a eraseable block |
| 147 | + * |
| 148 | + * @return Size of a eraseable block in bytes |
| 149 | + * @note Must be a multiple of the program size |
| 150 | + */ |
| 151 | + virtual bd_size_t get_erase_size() const; |
| 152 | + |
| 153 | + /** Get the total size of the underlying device |
| 154 | + * |
| 155 | + * @return Size of the underlying device in bytes |
| 156 | + */ |
| 157 | + virtual bd_size_t size() const; |
| 158 | + |
| 159 | + /** Get the BlockDevice class type. |
| 160 | + * |
| 161 | + * @return A string representation of the BlockDevice class type. |
| 162 | + */ |
| 163 | + virtual const char *get_type() const; |
| 164 | + |
| 165 | +private: |
| 166 | + mbed::I2C *_i2c; |
| 167 | + uint32_t _i2c_buffer[sizeof(mbed::I2C) / sizeof(uint32_t)]; |
| 168 | + uint8_t _i2c_addr; |
| 169 | + uint32_t _size; |
| 170 | + uint32_t _block; |
| 171 | + |
| 172 | + int _sync(); |
| 173 | +}; |
| 174 | + |
| 175 | + |
| 176 | +#endif /* MBED_SD_BLOCK_DEVICE_H */ |
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