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mtd: spi-nor: introduce SR_BP_SHIFT define

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The shift variable of SR_BP is conclusive because the first bit of SR_BP
is fixed on all known flashes. Replace ffs operation with SR_BP_SHIFT.

Signed-off-by: Jungseung Lee <js07.lee@samsung.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
This commit is contained in:
Jungseung Lee 2020-01-13 14:59:05 +09:00 committed by Tudor Ambarus
parent 5b24efe7d5
commit 8c79fa6c44
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GPG key ID: 4B554F47A58D14E9
2 changed files with 7 additions and 6 deletions
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11
drivers/mtd/spi-nor/spi-nor.c
View file

@ -1767,7 +1767,6 @@ static void stm_get_locked_range(struct spi_nor *nor, u8 sr, loff_t *ofs,
struct mtd_info *mtd = &nor->mtd;
u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
u8 tb_mask = SR_TB_BIT5;
int shift = ffs(mask) - 1;
int pow;
if (nor->flags & SNOR_F_HAS_SR_TB_BIT6)
@ -1778,7 +1777,7 @@ static void stm_get_locked_range(struct spi_nor *nor, u8 sr, loff_t *ofs,
*ofs = 0;
*len = 0;
} else {
pow = ((sr & mask) ^ mask) >> shift;
pow = ((sr & mask) ^ mask) >> SR_BP_SHIFT;
*len = mtd->size >> pow;
if (nor->flags & SNOR_F_HAS_SR_TB && sr & tb_mask)
*ofs = 0;
@ -1860,7 +1859,7 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
int ret, status_old, status_new;
u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
u8 tb_mask = SR_TB_BIT5;
u8 shift = ffs(mask) - 1, pow, val;
u8 pow, val;
loff_t lock_len;
bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;
bool use_top;
@ -1909,7 +1908,7 @@ static int stm_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
* pow = ceil(log2(size / len)) = log2(size) - floor(log2(len))
*/
pow = ilog2(mtd->size) - ilog2(lock_len);
val = mask - (pow << shift);
val = mask - (pow << SR_BP_SHIFT);
if (val & ~mask)
return -EINVAL;
/* Don't "lock" with no region! */
@ -1946,7 +1945,7 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
int ret, status_old, status_new;
u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
u8 tb_mask = SR_TB_BIT5;
u8 shift = ffs(mask) - 1, pow, val;
u8 pow, val;
loff_t lock_len;
bool can_be_top = true, can_be_bottom = nor->flags & SNOR_F_HAS_SR_TB;
bool use_top;
@ -1997,7 +1996,7 @@ static int stm_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
if (lock_len == 0) {
val = 0; /* fully unlocked */
} else {
val = mask - (pow << shift);
val = mask - (pow << SR_BP_SHIFT);
/* Some power-of-two sizes are not supported */
if (val & ~mask)
return -EINVAL;

2
include/linux/mtd/spi-nor.h
View file

@ -137,6 +137,8 @@
#define SR1_QUAD_EN_BIT6 BIT(6)
#define SR_BP_SHIFT 2
/* Enhanced Volatile Configuration Register bits */
#define EVCR_QUAD_EN_MICRON BIT(7) /* Micron Quad I/O */