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drivers/mtd/w25.c: erase sector only if it is not in erased state

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Jussi Kivilinna 2017-05-31 09:09:24 -06:00 committed by Gregory Nutt
parent c7fcdf968d
commit 8b006e705e
1 changed files with 59 additions and 0 deletions
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59
drivers/mtd/w25.c
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@ -247,6 +247,7 @@ static void w25_unprotect(FAR struct w25_dev_s *priv);
static uint8_t w25_waitwritecomplete(FAR struct w25_dev_s *priv);
static inline void w25_wren(FAR struct w25_dev_s *priv);
static inline void w25_wrdi(FAR struct w25_dev_s *priv);
static bool w25_is_erased(struct w25_dev_s *priv, off_t address, off_t size);
static void w25_sectorerase(FAR struct w25_dev_s *priv, off_t offset);
static inline int w25_chiperase(FAR struct w25_dev_s *priv);
static void w25_byteread(FAR struct w25_dev_s *priv, FAR uint8_t *buffer,
@ -549,6 +550,55 @@ static inline void w25_wrdi(struct w25_dev_s *priv)
SPI_SELECT(priv->spi, SPIDEV_FLASH(0), false);
}
/************************************************************************************
* Name: w25_is_erased
************************************************************************************/
static bool w25_is_erased(struct w25_dev_s *priv, off_t address, off_t size)
{
size_t npages = size >> W25_PAGE_SHIFT;
uint32_t erased_32;
unsigned int i;
uint32_t *buf;
DEBUGASSERT((address % W25_PAGE_SIZE) == 0);
DEBUGASSERT((size % W25_PAGE_SIZE) == 0);
buf = kmm_malloc(W25_PAGE_SIZE);
if (!buf)
{
return false;
}
memset(&erased_32, W25_ERASED_STATE, sizeof(erased_32));
/* Walk all pages in given area. */
while (npages)
{
/* Check if all bytes of page is in erased state. */
w25_byteread(priv, (unsigned char *)buf, address, W25_PAGE_SIZE);
for (i = 0; i < W25_PAGE_SIZE / sizeof(uint32_t); i++)
{
if (buf[i] != erased_32)
{
/* Page not in erased state! */
kmm_free(buf);
return false;
}
}
address += W25_PAGE_SIZE;
npages--;
}
kmm_free(buf);
return true;
}
/************************************************************************************
* Name: w25_sectorerase
************************************************************************************/
@ -559,6 +609,15 @@ static void w25_sectorerase(struct w25_dev_s *priv, off_t sector)
finfo("sector: %08lx\n", (long)sector);
/* Check if sector is already erased. */
if (w25_is_erased(priv, address, W25_SECTOR_SIZE))
{
/* Sector already in erased state, so skip erase. */
return;
}
/* Wait for any preceding write or erase operation to complete. */
(void)w25_waitwritecomplete(priv);