/***************************************************************************
* Copyright (C) 2020 by Federico Amedeo Izzo IU2NUO, *
* Niccolò Izzo IU2KIN *
* Frederik Saraci IU2NRO *
* Silvano Seva IU2KWO *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 3 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, see *
***************************************************************************/
#include "W25Qx.h"
#include
#include
#include
#include
#include
#include
#define CMD_WRITE 0x02 /* Read data */
#define CMD_READ 0x03 /* Read data */
#define CMD_RDSTA 0x05 /* Read status register */
#define CMD_WREN 0x06 /* Write enable */
#define CMD_ESECT 0x20 /* Erase 4kB sector */
#define CMD_RSECR 0x48 /* Read security register */
#define CMD_WKUP 0xAB /* Release power down */
#define CMD_PDWN 0xB9 /* Power down */
/*
* Target-specific SPI interface functions, their implementation can be found
* in source files "spiFlash_xxx.c"
*/
extern uint8_t spiFlash_SendRecv(uint8_t val);
extern void spiFlash_init();
extern void spiFlash_terminate();
void W25Qx_init()
{
gpio_setMode(FLASH_CS, OUTPUT);
gpio_setPin(FLASH_CS);
spiFlash_init();
}
void W25Qx_terminate()
{
W25Qx_sleep();
gpio_setMode(FLASH_CS, INPUT);
spiFlash_terminate();
}
void W25Qx_wakeup()
{
gpio_clearPin(FLASH_CS);
(void) spiFlash_SendRecv(CMD_WKUP);
gpio_setPin(FLASH_CS);
}
void W25Qx_sleep()
{
gpio_clearPin(FLASH_CS);
(void) spiFlash_SendRecv(CMD_PDWN);
gpio_setPin(FLASH_CS);
}
ssize_t W25Qx_readSecurityRegister(uint32_t addr, void* buf, size_t len)
{
uint32_t addrBase = addr & 0x3000;
uint32_t addrRange = addr & 0xCFFF;
if((addrBase < 0x1000) || (addrBase > 0x3000)) return -1; /* Out of base */
if(addrRange > 0xFF) return -1; /* Out of range */
/* Keep 256-byte boundary to avoid wrap-around when reading */
size_t readLen = len;
if((addrRange + len) > 0xFF)
{
readLen = 0xFF - (addrRange & 0xFF);
}
gpio_clearPin(FLASH_CS);
(void) spiFlash_SendRecv(CMD_RSECR); /* Command */
(void) spiFlash_SendRecv((addr >> 16) & 0xFF); /* Address high */
(void) spiFlash_SendRecv((addr >> 8) & 0xFF); /* Address middle */
(void) spiFlash_SendRecv(addr & 0xFF); /* Address low */
(void) spiFlash_SendRecv(0x00); /* Dummy byte */
for(size_t i = 0; i < readLen; i++)
{
((uint8_t *) buf)[i] = spiFlash_SendRecv(0x00);
}
gpio_setPin(FLASH_CS);
return ((ssize_t) readLen);
}
void W25Qx_readData(uint32_t addr, void* buf, size_t len)
{
gpio_clearPin(FLASH_CS);
(void) spiFlash_SendRecv(CMD_READ); /* Command */
(void) spiFlash_SendRecv((addr >> 16) & 0xFF); /* Address high */
(void) spiFlash_SendRecv((addr >> 8) & 0xFF); /* Address middle */
(void) spiFlash_SendRecv(addr & 0xFF); /* Address low */
for(size_t i = 0; i < len; i++)
{
((uint8_t *) buf)[i] = spiFlash_SendRecv(0x00);
}
gpio_setPin(FLASH_CS);
}
bool W25Qx_eraseSector(uint32_t addr)
{
gpio_clearPin(FLASH_CS);
(void) spiFlash_SendRecv(CMD_WREN); /* Write enable */
gpio_setPin(FLASH_CS);
delayUs(5);
gpio_clearPin(FLASH_CS);
(void) spiFlash_SendRecv(CMD_ESECT); /* Command */
(void) spiFlash_SendRecv((addr >> 16) & 0xFF); /* Address high */
(void) spiFlash_SendRecv((addr >> 8) & 0xFF); /* Address middle */
(void) spiFlash_SendRecv(addr & 0xFF); /* Address low */
gpio_setPin(FLASH_CS);
/*
* Wait till erase terminates.
* Timeout after 500ms, at 250us per tick
*/
uint16_t timeout = 2000;
while(timeout > 0)
{
delayUs(250);
timeout--;
gpio_clearPin(FLASH_CS);
(void) spiFlash_SendRecv(CMD_RDSTA); /* Read status */
uint8_t status = spiFlash_SendRecv(0x00);
gpio_setPin(FLASH_CS);
/* If busy flag is low, we're done */
if((status & 0x01) == 0) return true;
}
/* If we get here, we had a timeout */
return false;
}
ssize_t W25Qx_writePage(uint32_t addr, void* buf, size_t len)
{
/* Keep 256-byte boundary to avoid wrap-around when writing */
size_t addrRange = addr & 0x0001FF;
size_t writeLen = len;
if((addrRange + len) > 0x100)
{
writeLen = 0x100 - addrRange;
}
gpio_clearPin(FLASH_CS);
(void) spiFlash_SendRecv(CMD_WREN); /* Write enable */
gpio_setPin(FLASH_CS);
delayUs(5);
gpio_clearPin(FLASH_CS);
(void) spiFlash_SendRecv(CMD_WRITE); /* Command */
(void) spiFlash_SendRecv((addr >> 16) & 0xFF); /* Address high */
(void) spiFlash_SendRecv((addr >> 8) & 0xFF); /* Address middle */
(void) spiFlash_SendRecv(addr & 0xFF); /* Address low */
for(size_t i = 0; i < writeLen; i++)
{
uint8_t value = ((uint8_t *) buf)[i];
(void) spiFlash_SendRecv(value);
}
gpio_setPin(FLASH_CS);
/*
* Wait till write terminates.
* Timeout after 500ms, at 250us per tick
*/
uint16_t timeout = 2000;
while(timeout > 0)
{
delayUs(250);
timeout--;
gpio_clearPin(FLASH_CS);
(void) spiFlash_SendRecv(CMD_RDSTA); /* Read status */
uint8_t status = spiFlash_SendRecv(0x00);
gpio_setPin(FLASH_CS);
/* If busy flag is low, we're done */
if((status & 0x01) == 0) return ((ssize_t) writeLen);
}
/* If we get here, we had a timeout */
return -1;
}
bool W25Qx_writeData(uint32_t addr, void* buf, size_t len)
{
// Fail if we are trying to write more than 4K bytes
if(len > 4096)
return false;
// Fail if we are trying to write across 4K blocks,
// this would erase two 4K blocks for one write, which is not good for flash life
// We calculate block address using integer division of start and end address
uint32_t startBlockAddr = addr / 4096 * 4096;
uint32_t endBlockAddr = (addr + len - 1) / 4096 * 4096;
if(endBlockAddr != startBlockAddr)
return false;
// Read data from memory to check if it's already correct
// Allocate buffer for storing data read from memory
uint8_t *flashData;
flashData = (uint8_t *) malloc(len);
W25Qx_readData(addr, flashData, len);
// If data in flash corresponds to the passed data, do not perform the write
if(memcmp(buf, flashData, len) == 0)
{
// Free the buffer
free(flashData);
return true;
}
// Free the flash data buffer
free(flashData);
// Perform the actual read-erase-write of flash data
// Allocate 4096 bytes block for storing flash block to be erased
uint8_t *flashBlock;
flashBlock = (uint8_t *) malloc(4096);
// Read the 4K block from flash
W25Qx_readData(startBlockAddr, flashBlock, 4096);
uint32_t blockOffset = addr % 4096;
// Overwrite changed portion
memcpy(&flashBlock[blockOffset], buf, len);
// Erase the 4K block
if(!W25Qx_eraseSector(startBlockAddr))
{
// The erase operation failed, return failure
free(flashBlock);
return false;
}
// Write back the modified 4K block in 256 bytes chunks
for(uint32_t offset = 0; offset < 4096; offset += 256)
{
W25Qx_writePage(startBlockAddr + offset, &flashBlock[offset], 256);
}
// Free the 4K buffer
free(flashBlock);
return true;
}