Mbed OS Reference | I2CEEBlockDevice.h Source File

 /* Simple access class for I2C EEPROM chips like Microchip 24LC
  * Copyright (c) 2015 Robin Hourahane
  * SPDX-License-Identifier: Apache-2.0
  *
  * 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 "blockdevice/BlockDevice.h"
 #include "drivers/I2C.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.
      *  @param address_is_eight_bit Specifies whether the EEPROM device is using eight bit
      *                              addresses instead of 16 bit addresses. This is used for example
      *                              in AT24C series chips.
      */
     I2CEEBlockDevice(
         PinName sda, PinName scl, uint8_t address,
         bd_size_t size, bd_size_t block = 32,
         int bus_speed = 400000,
         bool address_is_eight_bit = false);
 
     /** Constructor to create an I2CEEBlockDevice on I2C pins
      *
      *  @param i2c                  The I2C instance pointer
      *  @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.
      *  @param address_is_eight_bit Specifies whether the EEPROM device is using eight bit
      *                              addresses instead of 16 bit addresses. This is used for example
      *                              in AT24C series chips.
      */
     I2CEEBlockDevice(
         mbed::I2C *i2c_obj, uint8_t address,
         bd_size_t size, bd_size_t block = 32,
         bool address_is_eight_bit = false);
 
     /** Destructor of I2CEEBlockDevice
      */
 
     virtual ~I2CEEBlockDevice();
 
     /** 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;
 
     /** Get the BlockDevice class type.
      *
      *  @return         A string representation of the BlockDevice class type.
      */
     virtual const char *get_type() const;
 
 private:
     mbed::I2C *_i2c;
     uint32_t _i2c_buffer[sizeof(mbed::I2C) / sizeof(uint32_t)];
     uint8_t _i2c_addr;
     bool _address_is_eight_bit;
     uint32_t _size;
     uint32_t _block;
 
     int _sync();
 
     /**
      * Gets the device's I2C address with respect to the requested page.
      * When eight-bit mode is disabled, this function is a noop.
      * When eight-bit mode is enabled, it sets the bits required
      * in the devices address. Other bits remain unchanged.
      * @param address An address in the requested page.
      * @return The device's I2C address for that page
      */
     uint8_t get_paged_device_address(bd_addr_t address);
 };
 
 
 #endif  /* MBED_SD_BLOCK_DEVICE_H */
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