[openwrt/openwrt] kernel: unlock MX25L6406E with 4 bit Block Protect

[LEDE Commits]

noltari pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/21311ca6b6144c86bcfea28bff51eb937e34029e

commit 21311ca6b6144c86bcfea28bff51eb937e34029e
Author: Sieng Piaw Liew <liew.s.piaw at gmail.com>
AuthorDate: Fri Oct 9 17:01:20 2020 +0800

    kernel: unlock MX25L6406E with 4 bit Block Protect
    
    Hacked in basic support for 4 bit Block Protection register, copied from
    linux-master. Needed to unlock Innacomm W3400V's SPI flash MX25L6406E,
    compatible with MX25L6405D.
    
    Signed-off-by: Sieng Piaw Liew <liew.s.piaw at gmail.com>
    [Amend commit description, refresh patch]
    Signed-off-by: Álvaro Fernández Rojas <noltari at gmail.com>
---
 ...unlock_mx25l6406e_with_4bit_block_protect.patch | 69 ++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/target/linux/generic/hack-5.4/400-unlock_mx25l6406e_with_4bit_block_protect.patch b/target/linux/generic/hack-5.4/400-unlock_mx25l6406e_with_4bit_block_protect.patch
new file mode 100644
index 0000000000..e25fdcd858
--- /dev/null
+++ b/target/linux/generic/hack-5.4/400-unlock_mx25l6406e_with_4bit_block_protect.patch
@@ -0,0 +1,69 @@
+--- a/drivers/mtd/spi-nor/spi-nor.c
++++ b/drivers/mtd/spi-nor/spi-nor.c
+@@ -196,7 +196,7 @@ struct flash_info {
+ 	u16		page_size;
+ 	u16		addr_width;
+ 
+-	u16		flags;
++	u32		flags;
+ #define SECT_4K			BIT(0)	/* SPINOR_OP_BE_4K works uniformly */
+ #define SPI_NOR_NO_ERASE	BIT(1)	/* No erase command needed */
+ #define SST_WRITE		BIT(2)	/* use SST byte programming */
+@@ -233,6 +233,10 @@ struct flash_info {
+ #define SPI_NOR_SKIP_SFDP	BIT(13)	/* Skip parsing of SFDP tables */
+ #define USE_CLSR		BIT(14)	/* use CLSR command */
+ #define SPI_NOR_OCTAL_READ	BIT(15)	/* Flash supports Octal Read */
++#define SPI_NOR_4BIT_BP		BIT(17) /*
++					 * Flash SR has 4 bit fields (BP0-3)
++					 * for block protection.
++					 */
+ 
+ 	/* Part specific fixup hooks. */
+ 	const struct spi_nor_fixups *fixups;
+@@ -1983,6 +1987,9 @@ static int spi_nor_clear_sr_bp(struct sp
+ 	int ret;
+ 	u8 mask = SR_BP2 | SR_BP1 | SR_BP0;
+ 
++	if (nor->flags & SNOR_F_HAS_4BIT_BP)
++		mask |= SR_BP3;
++
+ 	ret = read_sr(nor);
+ 	if (ret < 0) {
+ 		dev_err(nor->dev, "error while reading status register\n");
+@@ -2335,7 +2342,7 @@ static const struct flash_info spi_nor_i
+ 	{ "mx25l1606e",  INFO(0xc22015, 0, 64 * 1024,  32, SECT_4K) },
+ 	{ "mx25l3205d",  INFO(0xc22016, 0, 64 * 1024,  64, SECT_4K) },
+ 	{ "mx25l3255e",  INFO(0xc29e16, 0, 64 * 1024,  64, SECT_4K) },
+-	{ "mx25l6405d",  INFO(0xc22017, 0, 64 * 1024, 128, SECT_4K) },
++	{ "mx25l6405d",  INFO(0xc22017, 0, 64 * 1024, 128, SECT_4K | SPI_NOR_4BIT_BP) },
+ 	{ "mx25u2033e",  INFO(0xc22532, 0, 64 * 1024,   4, SECT_4K) },
+ 	{ "mx25u3235f",	 INFO(0xc22536, 0, 64 * 1024,  64,
+ 			 SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
+@@ -5024,6 +5031,9 @@ int spi_nor_scan(struct spi_nor *nor, co
+ 	if (info->flags & USE_CLSR)
+ 		nor->flags |= SNOR_F_USE_CLSR;
+ 
++	if (info->flags & SPI_NOR_4BIT_BP)
++		nor->flags |= SNOR_F_HAS_4BIT_BP;
++
+ 	if (info->flags & SPI_NOR_NO_ERASE)
+ 		mtd->flags |= MTD_NO_ERASE;
+ 
+--- a/include/linux/mtd/spi-nor.h
++++ b/include/linux/mtd/spi-nor.h
+@@ -127,6 +127,7 @@
+ #define SR_BP0			BIT(2)	/* Block protect 0 */
+ #define SR_BP1			BIT(3)	/* Block protect 1 */
+ #define SR_BP2			BIT(4)	/* Block protect 2 */
++#define SR_BP3			BIT(5)	/* Block protect 3 */
+ #define SR_TB			BIT(5)	/* Top/Bottom protect */
+ #define SR_SRWD			BIT(7)	/* SR write protect */
+ /* Spansion/Cypress specific status bits */
+@@ -243,6 +244,7 @@ enum spi_nor_option_flags {
+ 	SNOR_F_4B_OPCODES	= BIT(6),
+ 	SNOR_F_HAS_4BAIT	= BIT(7),
+ 	SNOR_F_HAS_LOCK		= BIT(8),
++	SNOR_F_HAS_4BIT_BP      = BIT(12),
+ };
+ 
+ /**