From: Jungseung Lee <js07.lee@samsung.com>
Date: Mon, 13 Jan 2020 05:59:05 +0000 (+0900)
Subject: mtd: spi-nor: introduce SR_BP_SHIFT define
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=8c79fa6c44deac8042bd747527fea06a32738158;p=openwrt%2Fstaging%2Fblogic.git

mtd: spi-nor: introduce SR_BP_SHIFT define

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>
---

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 864ed6f49e87..b5ef17b2897a 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -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;
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index 5abd91cc6dfa..61be6ed33097 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -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 */