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I2CEEBlockDevice.h
- Committer:
- JackB
- Date:
- 2018-07-23
- Revision:
- 0:45d514e74be4
File content as of revision 0:45d514e74be4:
/* Simple access class for I2C EEPROM chips like Microchip 24LC * Copyright (c) 2015 Robin Hourahane * * 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. */ #ifndef MBED_I2CEEPROM_BLOCK_DEVICE_H #define MBED_I2CEEPROM_BLOCK_DEVICE_H #include <mbed.h> #include "BlockDevice.h" /** BlockDevice for I2C based flash device such as * Microchip's 24LC or ATMEL's AT24C ranges * * @code * // Here's an example using a 24LC256 on a GR PEACH * #include "mbed.h" * #include "I2CEEBlockDevice.h" * * // Create EEPROM device on I2C bus with 32kbytes of memory * I2CEEBlockDevice i2cee(D14, D15, 0xa0, 32*1024); * * int main() { * printf("i2cee test\n"); * * // Initialize the device and print the memory layout * i2cee.init(); * printf("i2cee size: %llu\n", i2cee.size()); * printf("i2cee read size: %llu\n", i2cee.get_read_size()); * printf("i2cee program size: %llu\n", i2cee.get_program_size()); * printf("i2cee erase size: %llu\n", i2cee.get_erase_size()); * * // Write "Hello World!" to the first block * char *buffer = (char*)malloc(i2cee.get_erase_size()); * sprintf(buffer, "Hello World!\n"); * i2cee.erase(0, i2cee.get_erase_size()); * i2cee.program(buffer, 0, i2cee.get_erase_size()); * * // Read back what was stored * i2cee.read(buffer, 0, i2cee.get_erase_size()); * printf("%s", buffer); * * // Deinitialize the device * i2cee.deinit(); * } * @endcode */ class I2CEEBlockDevice : public BlockDevice { public: /** Constructor to create an I2CEEBlockDevice on I2C pins * * @param sda The pin name for the sda line of the I2C bus. * @param scl The pin name for the scl line of the I2C bus. * @param addr The 8bit I2C address of the chip, common range 0xa0 - 0xae. * @param size The size of the device in bytes * @param block The page size of the device in bytes, defaults to 32bytes * @param freq The frequency of the I2C bus, defaults to 400K. */ I2CEEBlockDevice( PinName sda, PinName scl, uint8_t address, bd_size_t size, bd_size_t block=32, int bus_speed=400000); /** Initialize a block device * * @return 0 on success or a negative error code on failure */ virtual int init(); /** Deinitialize a block device * * @return 0 on success or a negative error code on failure */ virtual int deinit(); /** Read blocks from a block device * * @param buffer Buffer to write blocks to * @param addr Address of block to begin reading from * @param size Size to read in bytes, must be a multiple of read block size * @return 0 on success, negative error code on failure */ virtual int read(void *buffer, bd_addr_t addr, bd_size_t size); /** Program blocks to a block device * * The blocks must have been erased prior to being programmed * * @param buffer Buffer of data to write to blocks * @param addr Address of block to begin writing to * @param size Size to write in bytes, must be a multiple of program block size * @return 0 on success, negative error code on failure */ virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size); /** Erase blocks on a block device * * The state of an erased block is undefined until it has been programmed * * @param addr Address of block to begin erasing * @param size Size to erase in bytes, must be a multiple of erase block size * @return 0 on success, negative error code on failure */ virtual int erase(bd_addr_t addr, bd_size_t size); /** Get the size of a readable block * * @return Size of a readable block in bytes */ virtual bd_size_t get_read_size() const; /** Get the size of a programable block * * @return Size of a programable block in bytes * @note Must be a multiple of the read size */ virtual bd_size_t get_program_size() const; /** Get the size of a eraseable block * * @return Size of a eraseable block in bytes * @note Must be a multiple of the program size */ virtual bd_size_t get_erase_size() const; /** Get the total size of the underlying device * * @return Size of the underlying device in bytes */ virtual bd_size_t size() const; private: I2C _i2c; uint8_t _i2c_addr; uint32_t _size; uint32_t _block; int _sync(); }; #endif /* MBED_I2CEEPROM_BLOCK_DEVICE_H */