arch/arm/src/stm32/stm32f20xxf40xx_flash.c

/****************************************************************************
 * arch/arm/src/stm32/stm32f20xxf40xx_flash.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you 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.
 *
 ****************************************************************************/

/* Provides standard flash access functions, to be used by the  flash mtd
 * driver.  The interface is defined in the include/nuttx/progmem.h
 *
 * Requirements during write/erase operations on FLASH:
 *  - HSI must be ON.
 *  - Low Power Modes are not permitted during write/erase
 */

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>
#include <nuttx/arch.h>
#include <nuttx/mutex.h>

#include <stdbool.h>
#include <assert.h>
#include <errno.h>

#include "stm32_flash.h"
#include "stm32_rcc.h"
#include "stm32_waste.h"
#include "arm_internal.h"

/* Only for the STM32F[2|4]0xx family. */

#if defined(CONFIG_STM32_STM32F20XX) || defined (CONFIG_STM32_STM32F4XXX)

#if defined(CONFIG_STM32_FLASH_CONFIG_DEFAULT)
#  warning "Default Flash Configuration Used - See Override Flash Size Designator"
#endif

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#define FLASH_KEY1         0x45670123
#define FLASH_KEY2         0xcdef89ab
#define FLASH_OPTKEY1      0x08192a3b
#define FLASH_OPTKEY2      0x4c5d6e7f
#define FLASH_ERASEDVALUE  0xff

/****************************************************************************
 * Private Data
 ****************************************************************************/

static mutex_t g_lock = NXMUTEX_INITIALIZER;

/****************************************************************************
 * Private Functions
 ****************************************************************************/

static void flash_unlock(void)
{
  while (getreg32(STM32_FLASH_SR) & FLASH_SR_BSY)
    {
      stm32_waste();
    }

  if (getreg32(STM32_FLASH_CR) & FLASH_CR_LOCK)
    {
      /* Unlock sequence */

      putreg32(FLASH_KEY1, STM32_FLASH_KEYR);
      putreg32(FLASH_KEY2, STM32_FLASH_KEYR);
    }
}

static void flash_lock(void)
{
  modifyreg32(STM32_FLASH_CR, 0, FLASH_CR_LOCK);
}

#if defined(CONFIG_STM32_FLASH_WORKAROUND_DATA_CACHE_CORRUPTION_ON_RWW)
static void data_cache_disable(void)
{
  modifyreg32(STM32_FLASH_ACR, FLASH_ACR_DCEN, 0);
}

static void data_cache_enable(void)
{
  /* Reset data cache */

  modifyreg32(STM32_FLASH_ACR, 0, FLASH_ACR_DCRST);

  /* Enable data cache */

  modifyreg32(STM32_FLASH_ACR, 0, FLASH_ACR_DCEN);
}
#endif /* defined(CONFIG_STM32_FLASH_WORKAROUND_DATA_CACHE_CORRUPTION_ON_RWW) */

/****************************************************************************
 * Public Functions
 ****************************************************************************/

int stm32_flash_unlock(void)
{
  int ret;

  ret = nxmutex_lock(&g_lock);
  if (ret < 0)
    {
      return ret;
    }

  flash_unlock();
  nxmutex_unlock(&g_lock);

  return ret;
}

int stm32_flash_lock(void)
{
  int ret;

  ret = nxmutex_lock(&g_lock);
  if (ret < 0)
    {
      return ret;
    }

  flash_lock();
  nxmutex_unlock(&g_lock);

  return ret;
}

/****************************************************************************
 * Name: stm32_flash_writeprotect
 *
 * Description:
 *   Enable or disable the write protection of a flash sector.
 *
 ****************************************************************************/

int stm32_flash_writeprotect(size_t page, bool enabled)
{
  uint32_t reg;
  uint32_t val;

  if (page >= STM32_FLASH_NPAGES)
    {
      return -EFAULT;
    }

  /* Select the register that contains the bit to be changed */

  if (page < 12)
    {
      reg = STM32_FLASH_OPTCR;
    }
#if defined(CONFIG_STM32_FLASH_CONFIG_I)
  else
    {
      reg = STM32_FLASH_OPTCR1;
      page -= 12;
    }
#else
  else
    {
      return -EFAULT;
    }
#endif

  /* Read the option status */

  val = getreg32(reg);

  /* Set or clear the protection */

  if (enabled)
    {
      val &= ~(1 << (16 + page));
    }
  else
    {
      val |=  (1 << (16 + page));
    }

  /* Unlock options */

  putreg32(FLASH_OPTKEY1, STM32_FLASH_OPTKEYR);
  putreg32(FLASH_OPTKEY2, STM32_FLASH_OPTKEYR);

  /* Write options */

  putreg32(val, reg);

  /* Trigger programming */

  modifyreg32(STM32_FLASH_OPTCR, 0, FLASH_OPTCR_OPTSTRT);

  /* Wait for completion */

  while (getreg32(STM32_FLASH_SR) & FLASH_SR_BSY)
    {
      stm32_waste();
    }

  /* Relock options */

  modifyreg32(STM32_FLASH_OPTCR, 0, FLASH_OPTCR_OPTLOCK);
  return 0;
}

size_t up_progmem_pagesize(size_t page)
{
  static const size_t page_sizes[STM32_FLASH_NPAGES] = STM32_FLASH_SIZES;

  if (page >= sizeof(page_sizes) / sizeof(*page_sizes))
    {
      return 0;
    }
  else
    {
      return page_sizes[page];
    }
}

size_t up_progmem_erasesize(size_t block)
{
  return up_progmem_pagesize(block);
}

ssize_t up_progmem_getpage(size_t addr)
{
  size_t page_end = 0;
  size_t i;

  if (addr >= STM32_FLASH_BASE)
    {
      addr -= STM32_FLASH_BASE;
    }

  if (addr >= STM32_FLASH_SIZE)
    {
      return -EFAULT;
    }

  for (i = 0; i < STM32_FLASH_NPAGES; ++i)
    {
      page_end += up_progmem_pagesize(i);
      if (page_end > addr)
        {
          return i;
        }
    }

  return -EFAULT;
}

size_t up_progmem_getaddress(size_t page)
{
  size_t base_address = STM32_FLASH_BASE;
  size_t i;

  if (page >= STM32_FLASH_NPAGES)
    {
      return SIZE_MAX;
    }

  for (i = 0; i < page; ++i)
    {
      base_address += up_progmem_pagesize(i);
    }

  return base_address;
}

size_t up_progmem_neraseblocks(void)
{
  return STM32_FLASH_NPAGES;
}

bool up_progmem_isuniform(void)
{
#ifdef STM32_FLASH_PAGESIZE
  return true;
#else
  return false;
#endif
}

ssize_t up_progmem_ispageerased(size_t page)
{
  size_t addr;
  size_t count;
  size_t bwritten = 0;

  if (page >= STM32_FLASH_NPAGES)
    {
      return -EFAULT;
    }

  /* Verify */

  for (addr = up_progmem_getaddress(page), count = up_progmem_pagesize(page);
       count; count--, addr++)
    {
      if (getreg8(addr) != FLASH_ERASEDVALUE)
        {
          bwritten++;
        }
    }

  return bwritten;
}

ssize_t up_progmem_eraseblock(size_t block)
{
  if (block >= STM32_FLASH_NPAGES)
    {
      return -EFAULT;
    }

  nxmutex_lock(&g_lock);

  /* Get flash ready and begin erasing single block */

  flash_unlock();

  modifyreg32(STM32_FLASH_CR, 0, FLASH_CR_SER);
  modifyreg32(STM32_FLASH_CR, FLASH_CR_SNB_MASK, FLASH_CR_SNB(block));
  modifyreg32(STM32_FLASH_CR, 0, FLASH_CR_STRT);

  while (getreg32(STM32_FLASH_SR) & FLASH_SR_BSY)
    {
      stm32_waste();
    }

  modifyreg32(STM32_FLASH_CR, FLASH_CR_SER, 0);
  nxmutex_unlock(&g_lock);

  /* Verify */

  if (up_progmem_ispageerased(block) == 0)
    {
      return up_progmem_pagesize(block); /* success */
    }
  else
    {
      return -EIO; /* failure */
    }
}

ssize_t up_progmem_write(size_t addr, const void *buf, size_t count)
{
  uint16_t *hword = (uint16_t *)buf;
  size_t written = count;

  /* STM32 requires half-word access */

  if (count & 1)
    {
      return -EINVAL;
    }

  /* Check for valid address range */

  if (addr >= STM32_FLASH_BASE)
    {
      addr -= STM32_FLASH_BASE;
    }

  if ((addr + count) > STM32_FLASH_SIZE)
    {
      return -EFAULT;
    }

  nxmutex_lock(&g_lock);

  /* Get flash ready and begin flashing */

  flash_unlock();

#if defined(CONFIG_STM32_FLASH_WORKAROUND_DATA_CACHE_CORRUPTION_ON_RWW)
  data_cache_disable();
#endif

  modifyreg32(STM32_FLASH_CR, 0, FLASH_CR_PG);

  /* TODO: implement up_progmem_write() to support other sizes than 16-bits */

  modifyreg32(STM32_FLASH_CR, FLASH_CR_PSIZE_MASK, FLASH_CR_PSIZE_X16);

  for (addr += STM32_FLASH_BASE; count; count -= 2, hword++, addr += 2)
    {
      /* Write half-word and wait to complete */

      putreg16(*hword, addr);

      while (getreg32(STM32_FLASH_SR) & FLASH_SR_BSY)
        {
          stm32_waste();
        }

      /* Verify */

      if (getreg32(STM32_FLASH_SR) & FLASH_CR_SER)
        {
          modifyreg32(STM32_FLASH_CR, FLASH_CR_PG, 0);
          nxmutex_unlock(&g_lock);
          return -EROFS;
        }

      if (getreg16(addr) != *hword)
        {
          modifyreg32(STM32_FLASH_CR, FLASH_CR_PG, 0);
          nxmutex_unlock(&g_lock);
          return -EIO;
        }
    }

  modifyreg32(STM32_FLASH_CR, FLASH_CR_PG, 0);

#if defined(CONFIG_STM32_FLASH_WORKAROUND_DATA_CACHE_CORRUPTION_ON_RWW)
  data_cache_enable();
#endif

  nxmutex_unlock(&g_lock);
  return written;
}

uint8_t up_progmem_erasestate(void)
{
  return FLASH_ERASEDVALUE;
}

#endif /* defined(CONFIG_STM32_STM32F20XX) || defined(CONFIG_STM32_STM32F4XXX) */