/* Write, assuming that someone has kindly erased the appropriate
* sector(s).
* Note: "block_offset" is the base of the current erase block.
* "data_offset" is the absolute address (from the 0-base of this
* device's memory) of the beginning of the write-destination.
* This device has no need for "block_offset", but it's included for
* function type compatibility.
*/
int alt_epcs_flash_write_block(alt_flash_dev* flash_info, int block_offset,
int data_offset, const void* data,
int length)
{
int ret_code;
alt_flash_epcs_dev *f = (alt_flash_epcs_dev*)flash_info;
int buffer_offset = 0;
int length_of_current_write;
ret_code = alt_epcs_test_address(flash_info, data_offset);
if (ret_code >= 0)
{
/* "Block" writes must be broken up into the page writes that
* the device understands. Partial page writes are allowed.
*/
while (length)
{
int next_page_start = (data_offset + f->page_size) & ~(f->page_size - 1);
length_of_current_write = MIN(length, next_page_start - data_offset);
epcs_write_buffer(f->register_base, data_offset, &((const alt_u8*)data)[buffer_offset], length_of_current_write);
length -= length_of_current_write;
buffer_offset += length_of_current_write;
data_offset = next_page_start;
}
}
return ret_code;
}
/*
*
* Erase the selected erase block ("sector erase", from the POV
* of the EPCS data sheet).
*/
int alt_epcs_flash_erase_block(alt_flash_dev* flash_info, int block_offset)
{
int ret_code = 0;
alt_flash_epcs_dev *f = (alt_flash_epcs_dev*)flash_info;
ret_code = alt_epcs_test_address(flash_info, block_offset);
if (ret_code >= 0)
{
/* Send the Sector Erase command, whose 3 address bytes are anywhere
* within the chosen sector.
*/
epcs_sector_erase(f->register_base, block_offset, f->four_bytes_mode);
}
return ret_code;
}
/*
*
* Erase the selected erase block ("sector erase", from the POV
* of the EPCS data sheet).
*/
int alt_epcs_flash_erase_block(alt_flash_dev* flash_info, int block_offset)
{
int ret_code = 0;
alt_flash_epcs_dev *f = (alt_flash_epcs_dev*)flash_info;
ret_code = alt_epcs_test_address(flash_info, block_offset);
if (ret_code >= 0)
{
/* Execute a WREN instruction */
epcs_write_enable(f->register_base);
/* Send the Sector Erase command, whose 3 address bytes are anywhere
* within the chosen sector.
*/
epcs_sector_erase(f->register_base, block_offset);
}
return ret_code;
}
/*
* If you try to read beyond the end of the memory, you'll wrap around
* to the beginning. Reads that start beyond the end of the memory are
* flagged as errors with EIO (is there a better error code?).
*/
int alt_epcs_flash_read(alt_flash_dev* flash_info, int offset,
void* dest_addr, int length)
{
int ret_code = 0;
alt_flash_epcs_dev *f = (alt_flash_epcs_dev*)flash_info;
ret_code = alt_epcs_test_address(flash_info, offset);
if (ret_code >= 0)
{
ret_code = epcs_read_buffer(f->register_base, offset, dest_addr, length);
/* epcs_read_buffer returns the number of buffers read, but
* alt_epcs_flash_read returns 0 on success, <0 on failure.
*/
if (ret_code == length)
{
ret_code = 0;
}
}
return ret_code;
}
