ARMmbed
/
mbed-os
mirror of https://github.com/ARMmbed/mbed-os.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Add Eight-Bit-Adressing mode to I2CEEBlockDevice. 

When dealing with EEPROMs without a 16 bit adressing, the current
implementation does not work, as it writes a 16 bit address to the chip.
This may cause undefined behaviour.
This change adds a new constructor argument to enable this new eight-bit
mode. It defaults to false to not break existing code.
This constructor argument should actually never be necessary to manually
set, except when dealing with cheap devices.
pull/12446/head
Stephan Brunner 2020-02-16 12:47:20 +01:00
parent 3d038e55ee
commit cd34860bd0
2 changed files with 51 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
components/storage/blockdevice/COMPONENT_I2CEE/I2CEEBlockDevice.cpp
View File

@ -22,8 +22,10 @@ using namespace mbed;
I2CEEBlockDevice::I2CEEBlockDevice(
PinName sda, PinName scl, uint8_t addr,
bd_size_t size, bd_size_t block, int freq)
: _i2c_addr(addr), _size(size), _block(block)
bd_size_t size, bd_size_t block, int freq,
bool address_is_eight_bit)
: _i2c_addr(addr), _size(size), _block(block),
_address_is_eight_bit(address_is_eight_bit)
{
_i2c = new (_i2c_buffer) I2C(sda, scl);
_i2c->frequency(freq);
@ -31,8 +33,10 @@ I2CEEBlockDevice::I2CEEBlockDevice(
I2CEEBlockDevice::I2CEEBlockDevice(
I2C *i2c_obj, uint8_t addr,
bd_size_t size, bd_size_t block)
: _i2c_addr(addr), _size(size), _block(block)
bd_size_t size, bd_size_t block,
bool address_is_eight_bit)
: _i2c_addr(addr), _size(size), _block(block),
_address_is_eight_bit(address_is_eight_bit)
{
_i2c = i2c_obj;
}
@ -60,9 +64,15 @@ int I2CEEBlockDevice::read(void *buffer, bd_addr_t addr, bd_size_t size)
_i2c->start();
if (!_i2c->write(_i2c_addr | 0) ||
!_i2c->write((char)(addr >> 8)) ||
!_i2c->write((char)(addr & 0xff))) {
if (!_i2c->write(_i2c_addr | 0)) {
return BD_ERROR_DEVICE_ERROR;
}
if (!_address_is_eight_bit && !_i2c->write((char)(addr >> 8))) {
return BD_ERROR_DEVICE_ERROR;
}
if (!_i2c->write((char)(addr & 0xff))) {
return BD_ERROR_DEVICE_ERROR;
}
@ -92,9 +102,15 @@ int I2CEEBlockDevice::program(const void *buffer, bd_addr_t addr, bd_size_t size
_i2c->start();
if (!_i2c->write(_i2c_addr | 0) ||
!_i2c->write((char)(addr >> 8)) ||
!_i2c->write((char)(addr & 0xff))) {
if (!_i2c->write(_i2c_addr | 0)) {
return BD_ERROR_DEVICE_ERROR;
}
if (!_address_is_eight_bit && !_i2c->write((char)(addr >> 8))) {
return BD_ERROR_DEVICE_ERROR;
}
if (!_i2c->write((char)(addr & 0xff))) {
return BD_ERROR_DEVICE_ERROR;
}

40
components/storage/blockdevice/COMPONENT_I2CEE/I2CEEBlockDevice.h
View File

@ -59,29 +59,37 @@ 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 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 should not be needed
* unless dealing with very cheap devices.
*/
I2CEEBlockDevice(
PinName sda, PinName scl, uint8_t address,
bd_size_t size, bd_size_t block = 32,
int bus_speed = 400000);
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 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 should not be needed
* unless dealing with very cheap devices.
*/
I2CEEBlockDevice(
mbed::I2C *i2c_obj, uint8_t address,
bd_size_t size, bd_size_t block = 32);
bd_size_t size, bd_size_t block = 32,
bool address_is_eight_bit = false);
/** Destructor of I2CEEBlockDevice
*/
@ -169,6 +177,8 @@ private:
uint32_t _size;
uint32_t _block;
bool _address_is_eight_bit;
int _sync();
};