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Diff: I2CEEBlockDevice.h
- Revision:
- 0:45d514e74be4
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/I2CEEBlockDevice.h Mon Jul 23 12:23:08 2018 +0000 @@ -0,0 +1,153 @@ +/* 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 */