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Remove overcomplicated code from I2CEEBlockDevice

pull/12446/head
Stephan Brunner 2020-02-18 18:40:29 +01:00
parent 7c589ae172
commit 532f3786a0
No known key found for this signature in database
GPG Key ID: D3CD7237AFB7EF6B
2 changed files with 58 additions and 137 deletions
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112
components/storage/blockdevice/COMPONENT_I2CEE/I2CEEBlockDevice.cpp
View File

@ -62,45 +62,44 @@ int I2CEEBlockDevice::read(void *buffer, bd_addr_t addr, bd_size_t size)
// Check the address and size fit onto the chip.
MBED_ASSERT(is_valid_read(addr, size));
auto *charBuffer = reinterpret_cast<char *>(buffer);
auto *pBuffer = reinterpret_cast<char *>(buffer);
while (size > 0) {
uint32_t off = addr % _block;
uint32_t chunk = (off + size < _block) ? size : (_block - off);
auto const handler = [&](const bd_addr_t &pagedStart, const bd_size_t &pagedLength, const uint8_t &pagedDeviceAddress) -> int {
_i2c->start();
if (1 != _i2c->write(pagedDeviceAddress))
{
if (1 != _i2c->write(get_paged_device_address(addr))) {
return BD_ERROR_DEVICE_ERROR;
}
if (!_address_is_eight_bit && 1 != _i2c->write((char)(pagedStart >> 8u)))
{
if (!_address_is_eight_bit && 1 != _i2c->write((char)(addr >> 8u))) {
return BD_ERROR_DEVICE_ERROR;
}
if (1 != _i2c->write((char)(pagedStart & 0xffu)))
{
if (1 != _i2c->write((char)(addr & 0xffu))) {
return BD_ERROR_DEVICE_ERROR;
}
_i2c->stop();
auto err = _sync();
if (err)
{
if (err) {
return err;
}
if (0 != _i2c->read(_i2c_addr, charBuffer, pagedLength))
{
if (0 != _i2c->read(_i2c_addr, pBuffer, chunk)) {
return BD_ERROR_DEVICE_ERROR;
}
charBuffer += size;
addr += chunk;
size -= chunk;
pBuffer += chunk;
}
return BD_ERROR_OK;
};
return do_paged(addr, size, handler);
}
int I2CEEBlockDevice::program(const void *buffer, bd_addr_t addr, bd_size_t size)
@ -108,22 +107,20 @@ int I2CEEBlockDevice::program(const void *buffer, bd_addr_t addr, bd_size_t size
// Check the addr and size fit onto the chip.
MBED_ASSERT(is_valid_program(addr, size));
auto const *charBuffer = reinterpret_cast<char const *>(buffer);
auto const *pBuffer = reinterpret_cast<char const *>(buffer);
auto const handler = [&](const bd_addr_t &pagedStart, const bd_size_t &pagedLength, const uint8_t &pagedDeviceAddress) -> int {
// While we have some more data to write.
while (size > 0)
{
while (size > 0) {
uint32_t off = addr % _block;
uint32_t chunk = (off + size < _block) ? size : (_block - off);
_i2c->start();
if (1 != _i2c->write(pagedDeviceAddress)) {
if (1 != _i2c->write(get_paged_device_address(addr))) {
return BD_ERROR_DEVICE_ERROR;
}
if (!_address_is_eight_bit && 1 != _i2c->write((char)(pagedStart >> 8u))) {
if (!_address_is_eight_bit && 1 != _i2c->write((char)(addr >> 8u))) {
return BD_ERROR_DEVICE_ERROR;
}
@ -132,7 +129,7 @@ int I2CEEBlockDevice::program(const void *buffer, bd_addr_t addr, bd_size_t size
}
for (unsigned i = 0; i < chunk; i++) {
if (1 != _i2c->write(charBuffer[i])) {
if (1 != _i2c->write(pBuffer[i])) {
return BD_ERROR_DEVICE_ERROR;
}
}
@ -147,14 +144,10 @@ int I2CEEBlockDevice::program(const void *buffer, bd_addr_t addr, bd_size_t size
addr += chunk;
size -= chunk;
charBuffer += chunk;
pBuffer += chunk;
}
return BD_ERROR_OK;
};
auto const originalSize = size;
return do_paged(addr, originalSize, handler);
}
int I2CEEBlockDevice::erase(bd_addr_t addr, bd_size_t size)
@ -204,68 +197,13 @@ const char *I2CEEBlockDevice::get_type() const
return "I2CEE";
}
int I2CEEBlockDevice::do_paged(const bd_addr_t &startAddress,
const bd_size_t &length,
const paged_handler &handler)
{
// This helper is only used for eight bit mode.
if (!this->_address_is_eight_bit) {
return handler(startAddress, length, get_paged_device_address(0));
}
auto currentStartAddress = startAddress;
auto const pageSize = 256;
bd_size_t lengthDone = 0;
while (lengthDone != length) {
/* Integer division => Round down */
uint8_t const currentPage = currentStartAddress / pageSize;
bd_addr_t const nextPageBegin = (currentPage + 1) * pageSize;
bd_addr_t const currentReadEndAddressExclusive = std::min(nextPageBegin, startAddress + length);
bd_size_t const currentLength = currentReadEndAddressExclusive - currentStartAddress;
bd_addr_t const pagedBegin = currentStartAddress - (currentPage * pageSize);
uint8_t const pagedDeviceAddress = get_paged_device_address(currentPage);
auto const handlerReturn = handler(pagedBegin, currentLength, pagedDeviceAddress);
if (handlerReturn != BD_ERROR_OK) {
return handlerReturn;
}
currentStartAddress = currentReadEndAddressExclusive;
lengthDone += currentLength;
}
return BD_ERROR_OK;
}
uint8_t I2CEEBlockDevice::get_paged_device_address(const uint8_t &page)
uint8_t I2CEEBlockDevice::get_paged_device_address(const bd_addr_t &address)
{
if (!this->_address_is_eight_bit) {
return this->_i2c_addr;
} else {
// This method uses a dynamically created bit mask for the page given.
// This ensures compatibility with all sizes of ICs.
// E. g. the 512K variants have two user address bits and one page bit.
// We don't want to forcefully override the two user address bits.
// Create a mask to cover all bits required to set page
// i starts at one because the LSB is used for R/W in I2C
uint8_t i = 1;
uint8_t addressMask = 0;
auto p = page;
while (p != 0u) {
addressMask |= (1u << i);
p >>= 1u;
i++;
}
uint8_t pagedDeviceAddress = this->_i2c_addr & static_cast<uint8_t>(~addressMask);
// Assert page < 0b111, because we don't have
// more bits for page encoding
// Don't actually write 0b111, this is a nonstandard extension.
MBED_ASSERT(page < 0x7);
pagedDeviceAddress |= static_cast<uint8_t>(page << 1u);
return pagedDeviceAddress;
// Use the three least significant bits of the 2nd byte as the page
// The page will be bits 2-4 of the user defined addresses.
return this->_i2c_addr | ((address & 0x0700u) >> 7u);
}
}

21
components/storage/blockdevice/COMPONENT_I2CEE/I2CEEBlockDevice.h
View File

@ -181,32 +181,15 @@ private:
int _sync();
using paged_handler = std::function<int(const bd_addr_t &address, const bd_size_t &length, const uint8_t &deviceAddress)>;
/**
* Executes a handler across page boundaries for eight bit mode.
* When eight bit mode is disabled, the function does not do paging at all.
* When eight bit mode is enabled, this function splits the requested
* address space into multiple pages when needed.
* This is required when a read or write must be done across multiple pages.
*
* @param startAddress The address to start
* @param length The requested length of the operation
* @param handler The handler to execute
* @return Returns 0 when all calls to handler() return 0. Otherwise the
* error code from the first non-zero handler() call.
*/
int do_paged(const bd_addr_t &startAddress, const bd_size_t &length, const paged_handler &handler);
/**
* 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 for this bit
* in the devices address. Other bits remain unchained.
* @param page The requested page
* @param address An address in the requested page.
* @return The device's I2C address for that page
*/
uint8_t get_paged_device_address(const uint8_t &page);
uint8_t get_paged_device_address(const bd_addr_t &address);
};