add flash read/write support

This commit is contained in:
pnb 2015-09-05 10:37:13 +02:00
parent 3c35458ac2
commit c83d533d90
3 changed files with 858 additions and 0 deletions

View file

@ -132,6 +132,11 @@ config EFM32_RMU
bool "Reset Management Unit (RMU) "
default n
config EFM32_FLASHPROG
bool "Enable Erase/Write flash function (MSC) "
default n
select ARCH_HAVE_RAMFUNCS
config EFM32_RMU_DEBUG
bool "Reset Management Unit (RMU) DEBUG "
default n

View file

@ -105,6 +105,10 @@ endif
CHIP_CSRCS = efm32_start.c efm32_clockconfig.c efm32_irq.c efm32_timerisr.c
CHIP_CSRCS += efm32_gpio.c efm32_lowputc.c efm32_timer.c efm32_i2c.c
ifeq ($(CONFIG_EFM32_FLASHPROG),y)
CHIP_CSRCS += efm32_flash.c
endif
ifneq ($(CONFIG_ARCH_IDLE_CUSTOM),y)
CHIP_CSRCS += efm32_idle.c
endif

View file

@ -0,0 +1,849 @@
/*****************************************************************************
* arch/arm/src/efm32/efm32_flash.c
*
* Copyright 2014 Silicon Laboratories, Inc. http://www.silabs.com</b>
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software.@n
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.@n
* 3. This notice may not be removed or altered from any source distribution.
*
* DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Laboratories, Inc.
* has no obligation to support this Software. Silicon Laboratories, Inc. is
* providing the Software "AS IS", with no express or implied warranties of any
* kind, including, but not limited to, any implied warranties of
* merchantability or fitness for any particular purpose or warranties against
* infringement of any proprietary rights of a third party.
*
* Silicon Laboratories, Inc. will not be liable for any consequential,
* incidental, or special damages, or any other relief, or for any claim by
* any third party, arising from your use of this Software.
*
* Copyright (C) 2015 Pierre-Noel Bouteville. All rights reserved.
* Author: Pierre-Noel Bouteville <pnb990@gmail.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/* 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 <errno.h>
#include <arch/board/board.h>
#include "up_internal.h"
#include "up_arch.h"
#include "chip/efm32_msc.h"
#include "chip/efm32_devinfo.h"
#include "efm32_bitband.h"
#include "nuttx/progmem.h"
/* Only for the EFM32 family for now */
#if ( defined(CONFIG_ARCH_CHIP_EFM32) && defined(CONFIG_EFM32_FLASHPROG) )
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
#ifndef CONFIG_ARCH_RAMFUNCS
# error "Flashing function should executed in ram"
#endif
#ifndef EFM32_USERDATA_SIZE
# error "EFM32_USERDATA_SIZE should be defined"
#endif
#ifndef EFM32_USERDATA_BASE
# define "EFM32_USERDATA_BASE should be defined"
#endif
#ifndef EFM32_USERDATA_NPAGES
# define "EFM32_FLASH_NPAGES should be defined"
#endif
#ifndef EFM32_USERDATA_PAGESIZE
# define EFM32_USERDATA_PAGESIZE (EFM32_USERDATA_SIZE/EFM32_USERDATA_NPAGES)
#endif
/*
* brief:
* The timeout used while waiting for the flash to become ready after
* a write. This number indicates the number of iterations to perform before
* issuing a timeout.
* note:
* This timeout is set very large (in the order of 100x longer than
* necessary). This is to avoid any corner cases.
*
*/
#define MSC_PROGRAM_TIMEOUT 10000000ul
/************************************************************************************
* Private Functions
************************************************************************************/
void efm32_flash_unlock(void)
{
uint32_t regval;
/* Unlock the EFM32_MSC */
putreg32(MSC_UNLOCK_CODE,EFM32_MSC_LOCK);
/* Disable writing to the flash */
bitband_set_peripheral(EFM32_MSC_WRITECTRL,_MSC_WRITECTRL_WREN_SHIFT,0);
#if defined( _MSC_TIMEBASE_MASK )
regval = getreg32(EFM32_MSC_TIMEBASE);
regval &= ~(_MSC_TIMEBASE_BASE_MASK | _MSC_TIMEBASE_PERIOD_MASK);
/* Configure EFM32_MSC_TIMEBASE according to selected frequency */
if (BOARD_AUXCLK_FREQUENCY > 7000000)
{
uint32_t freq;
uint32_t cycles;
/* Calculate number of clock cycles for 1us as base period */
freq = (BOARD_AUXCLK_FREQUENCY * 11) / 10;
cycles = (freq / 1000000) + 1;
/* Configure clock cycles for flash timing */
regval |= MSC_TIMEBASE_PERIOD_1US;
regval |= (cycles << _MSC_TIMEBASE_BASE_SHIFT);
}
else
{
uint32_t freq;
uint32_t cycles;
/* Calculate number of clock cycles for 5us as base period */
freq = (BOARD_AUXCLK_FREQUENCY * 5 * 11) / 10;
cycles = (freq / 1000000) + 1;
/* Configure clock cycles for flash timing */
regval |= MSC_TIMEBASE_PERIOD_5US;
regval |= (cycles << _MSC_TIMEBASE_BASE_SHIFT);
}
putreg32(regval,EFM32_MSC_TIMEBASE);
#endif
}
/*******************************************************************************
* Name: msc_load_verify_address
* Perform address phase of FLASH write cycle.
* Description:
* This function performs the address phase of a Flash write operation by
* writing the given flash address to the ADDRB register and issuing the
* LADDRIM command to load the address.
* note:
* This function MUST be executed from RAM. Failure to execute this portion
* of the code in RAM will result in a hardfault. For IAR, Rowley and
* Codesourcery this will be achieved automatically. For Keil uVision 4 you
* must define a section called "ram_code" and place this manually in your
* project's scatter file.
* param:
* address : Address in flash memory. Must be aligned at a 4 byte boundary.
* return:
* Returns the status of the address load operation, #msc_Return_TypeDef
* OK - Operation completed successfully.
* -EBUSY - Busy timeout.
* -EINVAL - Operation tried to access a non-flash area.
* -EACCES - Operation tried to access a locked area of the flash.
*******************************************************************************
*/
int __ramfunc__ msc_load_verify_address(uint32_t* address)
{
uint32_t status;
uint32_t timeout;
/* Wait for the MSC to become ready. */
timeout = MSC_PROGRAM_TIMEOUT;
while ((getreg32(EFM32_MSC_STATUS) & MSC_STATUS_BUSY) && (timeout != 0))
{
timeout--;
}
/* Check for timeout */
if (timeout == 0)
{
return -EBUSY;
}
/* Load address */
putreg32((uint32_t) (address),EFM32_MSC_ADDRB);
putreg32(MSC_WRITECMD_LADDRIM,EFM32_MSC_WRITECMD);
status = getreg32(EFM32_MSC_STATUS);
if (status & (MSC_STATUS_INVADDR | MSC_STATUS_LOCKED))
{
/* Check for invalid address */
if (status & MSC_STATUS_INVADDR)
return -EINVAL;
/* Check for write protected page */
if (status & MSC_STATUS_LOCKED)
return -EACCES;
}
return OK;
}
/*******************************************************************************
* Name:msc_load_data
* Perform data phase of FLASH write cycle.
* Description:
* This function performs the data phase of a Flash write operation by loading
* the given number of 32-bit words to the WDATA register.
* note:
* This function MUST be executed from RAM. Failure to execute this portion
* of the code in RAM will result in a hardfault. For IAR, Rowley and
* Codesourcery this will be achieved automatically. For Keil uVision 4 you
* must define a section called "ram_code" and place this manually in your
* project's scatter file.
* paramelters:
* data : Pointer to the first data word to load.
* num_words : Number of data words (32-bit) to load.
* return:
* Returns the status of the data load operation, #msc_Return_TypeDef
* OK - Operation completed successfully.
* -ETIMEDOUT - Operation timed out waiting for flash operation
* to complete.
******************************************************************************/
int __ramfunc__ msc_load_write_data(uint32_t* data, uint32_t num_words,
bool write_strategy_safe)
{
int timeout;
int word_index;
int words_per_data_phase;
int ret = 0;
#if defined( _MSC_WRITECTRL_LPWRITE_MASK ) && defined( _MSC_WRITECTRL_WDOUBLE_MASK )
/* If LPWRITE (Low Power Write) is NOT enabled, set WDOUBLE (Write Double word) */
if (!(getreg32(EFM32_MSC_WRITECTRL) & MSC_WRITECTRL_LPWRITE))
{
/* If the number of words to be written are odd, we need to align by writing
* a single word first, before setting the WDOUBLE bit.
*/
if (num_words & 0x1)
{
/* Wait for the msc to be ready for the next word. */
timeout = MSC_PROGRAM_TIMEOUT;
while ((!(getreg32(EFM32_MSC_STATUS) & MSC_STATUS_WDATAREADY)) && \
(timeout != 0))
{
timeout--;
}
/* Check for timeout */
if (timeout == 0)
{
return -ETIMEDOUT;
}
/* Clear double word option, in order to write one single word. */
bitband_set_peripheral(EFM32_MSC_WRITECTRL,_MSC_WRITECTRL_WDOUBLE_SHIFT,0);
/* Write first data word. */
putreg32(*data++,EFM32_MSC_WDATA);
putreg32(MSC_WRITECMD_WRITEONCE,EFM32_MSC_WRITECMD);
/* Wait for the operation to finish. It may be required to change the
* WDOUBLE config after the initial write. It should not be changed
* while BUSY.
*/
timeout = MSC_PROGRAM_TIMEOUT;
while ((getreg32(EFM32_MSC_STATUS) & MSC_STATUS_BUSY) && (timeout != 0))
{
timeout--;
}
/* Check for timeout */
if (timeout == 0)
{
return -ETIMEDOUT;
}
/* Subtract this initial odd word for the write loop below */
num_words --;
ret = 0;
}
/* Now we can set the double word option in order to write two words per
* data phase.
*/
bitband_set_peripheral(EFM32_MSC_WRITECTRL,_MSC_WRITECTRL_WDOUBLE_SHIFT,1);
words_per_data_phase = 2;
}
else
#endif
{
words_per_data_phase = 1;
}
/* Write the rest as double word write if wordsPerDataPhase == 2 */
if ( num_words > 0 )
{
/* Write strategy: msc_write_int_safe */
if ( write_strategy_safe )
{
/* Requires a system core clock at 1MHz or higher */
DEBUGASSERT(BOARD_SYSTEM_FREQUENCY >= 1000000);
word_index = 0;
while(word_index < num_words)
{
putreg32(*data++,EFM32_MSC_WDATA);
word_index++;
if (words_per_data_phase == 2)
{
while (!(getreg32(EFM32_MSC_STATUS) & MSC_STATUS_WDATAREADY))
{
}
putreg32(*data++,EFM32_MSC_WDATA);
word_index++;
}
putreg32(MSC_WRITECMD_WRITEONCE,EFM32_MSC_WRITECMD);
/* Wait for the transaction to finish. */
timeout = MSC_PROGRAM_TIMEOUT;
while ((getreg32(EFM32_MSC_STATUS) & MSC_STATUS_BUSY) && \
(timeout != 0))
{
timeout--;
}
/* Check for timeout */
if (timeout == 0)
{
ret = -ETIMEDOUT;
break;
}
#if defined( CONFIG_EFM32_EFM32G )
putreg32(getreg32(EFM32_MSC_ADDRB)+4,EFM32_MSC_ADDRB);
putreg32(MSC_WRITECMD_LADDRIM,EFM32_MSC_WRITECMD);
#endif
}
}
/* Write strategy: msc_write_fast */
else
{
#if defined( CONFIG_EFM32_EFM32G )
/* Gecko does not have auto-increment of ADDR. */
DEBUGASSERT(0);
#else
/* Requires a system core clock at 14MHz or higher */
DEBUGASSERT(BOARD_SYSTEM_FREQUENCY >= 14000000);
word_index = 0;
while(word_index < num_words)
{
/* Wait for the MSC to be ready for the next word. */
while (!(getreg32(EFM32_MSC_STATUS) & MSC_STATUS_WDATAREADY))
{
uint32_t regval;
/* If the write to MSC->WDATA below missed the 30us timeout
* and the following MSC_WRITECMD_WRITETRIG command arrived
* while MSC_STATUS_BUSY is 1, then the MSC_WRITECMD_WRITETRIG
* could be ignored by the MSC. In this case,
* MSC_STATUS_WORDTIMEOUT is set to 1 and MSC_STATUS_BUSY is
* 0. A new trigger is therefore needed here to complete write
* of data in MSC->WDATA. If WDATAREADY became high since
* entry into this loop, exit and continue to the next WDATA
* write.
*/
regval = getreg32(EFM32_MSC_STATUS);
regval &= MSC_STATUS_WORDTIMEOUT;
regval &= MSC_STATUS_BUSY;
regval &= MSC_STATUS_WDATAREADY;
if ( regval == MSC_STATUS_WORDTIMEOUT )
{
putreg32(MSC_WRITECMD_WRITETRIG,EFM32_MSC_WRITECMD);
}
}
putreg32(*data,EFM32_MSC_WDATA);
if (( words_per_data_phase == 1) || \
((words_per_data_phase == 2) && (word_index & 0x1)))
{
putreg32(MSC_WRITECMD_WRITETRIG,EFM32_MSC_WRITECMD);
}
data++;
word_index++;
}
/* Wait for the transaction to finish. */
timeout = MSC_PROGRAM_TIMEOUT;
while ((getreg32(EFM32_MSC_STATUS) & MSC_STATUS_BUSY) && \
(timeout != 0))
{
timeout--;
}
/* Check for timeout */
if (timeout == 0)
{
ret = -ETIMEDOUT;
}
#endif
}
}
#ifdef _MSC_WRITECTRL_WDOUBLE_MASK
/* Clear double word option, which should not be left on when returning. */
bitband_set_peripheral(EFM32_MSC_WRITECTRL,_MSC_WRITECTRL_WDOUBLE_SHIFT,0);
#endif
return ret;
}
void efm32_flash_lock(void)
{
/* Disable writing to the flash */
bitband_set_peripheral(EFM32_MSC_WRITECTRL,_MSC_WRITECTRL_WREN_SHIFT,0);
/* Unlock the EFM32_MSC */
putreg32(0,EFM32_MSC_LOCK);
}
#ifndef EFM32_FLASH_SIZE
#define EFM32_FLASH_SIZE efm32_get_flash_size()
uint32_t efm32_get_flash_size(void)
{
uint32_t regval;
regval = getreg32(EFM32_DEVINFO_MEMINFO_SIZE);
regval = (regval & _DEVINFO_MEMINFO_SIZE_FLASH_MASK) \
>> _DEVINFO_MEMINFO_SIZE_FLASH_SHIFT;
return regval*1024;
}
#endif
#ifndef EFM32_FLASH_PAGESIZE
#define EFM32_FLASH_PAGESIZE efm32_get_flash_page_size()
uint32_t efm32_get_flash_page_size(void)
{
uint32_t regval;
regval = getreg32(EFM32_DEVINFO_MEMINFO_PAGE_SIZE);
regval = (regval & _DEVINFO_MEMINFO_FLASH_PAGE_SIZE_MASK) \
>> _DEVINFO_MEMINFO_FLASH_PAGE_SIZE_SHIFT;
if ( regval == 0xff )
return 512;
return 1<<(regval+10);
}
#endif
#ifndef EFM32_FLASH_NPAGES
#define EFM32_FLASH_NPAGES efm32_get_flash_page_nbr()
uint32_t efm32_get_flash_page_nbr(void)
{
return (EFM32_FLASH_SIZE/EFM32_FLASH_PAGESIZE);
}
#endif
/************************************************************************************
* Public Functions
************************************************************************************/
size_t up_progmem_pagesize(size_t page)
{
if (page < EFM32_FLASH_NPAGES)
return EFM32_FLASH_PAGESIZE;
page -= EFM32_FLASH_NPAGES;
if (page < EFM32_USERDATA_NPAGES)
return EFM32_USERDATA_PAGESIZE;
return 0;
}
ssize_t up_progmem_getpage(size_t addr)
{
#if ( EFM32_FLASH_BASE != 0 )
if ( (addr >= (EFM32_FLASH_BASE) ) && \
(addr < (EFM32_FLASH_BASE+EFM32_FLASH_SIZE) )
)
{
addr -= EFM32_FLASH_BASE;
return addr / EFM32_FLASH_PAGESIZE;
}
#else
if ( addr < EFM32_FLASH_SIZE )
{
return addr / EFM32_FLASH_PAGESIZE;
}
#endif
if ( (addr >= (EFM32_USERDATA_BASE) ) && \
(addr < (EFM32_USERDATA_BASE+EFM32_USERDATA_SIZE) )
)
{
addr -= EFM32_USERDATA_BASE;
return (addr / EFM32_USERDATA_NPAGES) + EFM32_FLASH_NPAGES;
}
return -EFAULT;
}
size_t up_progmem_getaddress(size_t page)
{
if (page < EFM32_FLASH_NPAGES)
{
return page * EFM32_FLASH_PAGESIZE + EFM32_FLASH_BASE;
}
page -= EFM32_FLASH_NPAGES;
if (page < EFM32_USERDATA_NPAGES)
{
return EFM32_USERDATA_BASE + (page * EFM32_USERDATA_NPAGES);
}
return SIZE_MAX;
}
size_t up_progmem_npages(void)
{
return EFM32_FLASH_NPAGES+EFM32_USERDATA_NPAGES;
}
bool up_progmem_isuniform(void)
{
return false;
}
ssize_t __ramfunc__ up_progmem_erasepage(size_t page)
{
int ret = 0;
int timeout;
uint32_t regval;
irqstate_t irqs;
if (page >= (EFM32_FLASH_NPAGES+EFM32_USERDATA_NPAGES))
{
return -EFAULT;
}
efm32_flash_unlock();
irqs = irqsave();
/* enable writing to the flash */
bitband_set_peripheral(EFM32_MSC_WRITECTRL,_MSC_WRITECTRL_WREN_SHIFT,1);
/* Load address */
putreg32((uint32_t)up_progmem_getaddress(page),EFM32_MSC_ADDRB);
putreg32(MSC_WRITECMD_LADDRIM,EFM32_MSC_WRITECMD);
regval = getreg32(EFM32_MSC_STATUS);
/* Check for invalid address */
if (regval & MSC_STATUS_INVADDR)
{
ret = -EINVAL;
}
/* Check for write protected page */
if ( ( ret == 0 ) && (regval & MSC_STATUS_LOCKED) )
{
ret = -EPERM;
}
/* Send erase page command */
if ( ret == 0 )
{
putreg32(MSC_WRITECMD_ERASEPAGE,EFM32_MSC_WRITECMD);
/* Wait for the erase to complete */
timeout = MSC_PROGRAM_TIMEOUT;
while ((getreg32(EFM32_MSC_STATUS) & MSC_STATUS_BUSY) && (timeout != 0))
{
timeout--;
}
if (timeout == 0)
{
ret = -ETIMEDOUT;
}
}
/* Disable writing to the MSC */
bitband_set_peripheral(EFM32_MSC_WRITECTRL,_MSC_WRITECTRL_WREN_SHIFT,0);
if ( ret == 0 )
{
/* Verify */
if (up_progmem_ispageerased(page) != 0)
{
ret = -EIO;
}
}
irqrestore(irqs);
if ( ret != 0 )
return ret;
/* success */
return up_progmem_pagesize(page);
}
ssize_t up_progmem_ispageerased(size_t page)
{
size_t addr;
size_t count;
size_t bwritten = 0;
if (page >= (EFM32_FLASH_NPAGES+EFM32_USERDATA_NPAGES))
{
return -EFAULT;
}
/* Verify */
for (addr = up_progmem_getaddress(page), count = up_progmem_pagesize(page);
count; count--, addr++)
{
if (getreg8(addr) != 0xff)
{
bwritten++;
}
}
return bwritten;
}
ssize_t __ramfunc__ up_progmem_write(size_t addr, const void *buf, size_t size)
{
int ret = 0;
int word_count;
int num_words;
int page_words;
uint32_t* p_data;
uint32_t* address = (uint32_t*) addr;
uint32_t num_bytes = size;
/* EFM32 requires word access */
if (addr & 3)
{
return -EINVAL;
}
/* EFM32 requires word access */
if (num_bytes & 3)
{
return -EINVAL;
}
efm32_flash_unlock();
/* enable writing to the flash */
bitband_set_peripheral(EFM32_MSC_WRITECTRL,_MSC_WRITECTRL_WREN_SHIFT,1);
/* Convert bytes to words */
num_words = num_bytes >> 2;
/* The following loop splits the data into chunks corresponding to flash pages.
* The address is loaded only once per page, because the hardware automatically
* increments the address internally for each data load inside a page.
*/
for (word_count = 0, p_data = (uint32_t*) buf; word_count < num_words; )
{
int page_bytes;
ssize_t page_idx;
irqstate_t irqs;
/* Compute the number of words to write to the current page. */
page_idx = up_progmem_getpage((size_t)address+(word_count<<2));
if ( page_idx < 0 )
{
ret = -EINVAL;
break;
}
page_bytes = up_progmem_pagesize(page_idx);
if ( page_bytes < 0 )
{
ret = -EINVAL;
break;
}
page_words = (page_bytes - (((uint32_t) (address + word_count)) & \
(page_bytes-1))) / sizeof(uint32_t);
if (page_words > num_words - word_count)
{
page_words = num_words - word_count;
}
irqs = irqsave();
/* First we load address. The address is auto-incremented within a page.
Therefore the address phase is only needed once for each page. */
ret = msc_load_verify_address(address + word_count);
/* Now write the data in the current page. */
if (ret == 0)
{
ret = msc_load_write_data( p_data, page_words, true );
}
irqrestore(irqs);
if (ret != 0 )
{
break;
}
word_count += page_words;
p_data += page_words;
}
/* Disable writing to the MSC */
bitband_set_peripheral(EFM32_MSC_WRITECTRL,_MSC_WRITECTRL_WREN_SHIFT,0);
#if (defined(CONFIG_EFM32_EFM32GG) || defined(CONFIG_EFM32_EFM32WG)) && (2==WORDS_PER_DATA_PHASE)
/* Turn off double word write cycle support. */
bitband_set_peripheral(EFM32_MSC_WRITECTRL,_MSC_WRITECTRL_WDOUBLE_SHIFT,0);
#endif
if (ret < 0 )
return ret;
return word_count;
}
#endif /* defined(CONFIG_ARCH_CHIP_EFM32) */