[PATCH v2 07/23] mtd: spi-nor: winbond: W25Q128JV-Q/N: Add quad page program capability

[Miquel Raynal]

The benefit is not massive @25MHz, yet this feature is not advertized
because these chips do not implement the 4BAIT table. Flag the quad page
program capability manually and earn a few % of write throughput.

Before:
$ flash_speed /dev/mtd0 -dc10
eraseblock write speed is 536 KiB/s
page write speed is 532 KiB/s
2 page write speed is 532 KiB/s

After:
$ flash_speed /dev/mtd0 -dc10
eraseblock write speed is 552 KiB/s
page write speed is 547 KiB/s
2 page write speed is 549 KiB/s

The QUAD_PP capability was historically not supported by non-SFDP chips,
so a Winbond wide late hook already makes sure the capability remains
disabled for them, for backward compatiblity reasons.

Signed-off-by: Miquel Raynal <miquel.raynal at bootlin.com>
---
+ dd 'if=/dev/urandom' 'of=./spi_test' 'bs=1M' 'count=2'
2+0 records in
2+0 records out
+ mtd_debug erase /dev/mtd0 0 2097152
Erased 2097152 bytes from address 0x00000000 in flash
+ mtd_debug read /dev/mtd0 0 2097152 spi_read
Copied 2097152 bytes from address 0x00000000 in flash to spi_read
+ hexdump spi_read
0000000 ffff ffff ffff ffff ffff ffff ffff ffff
*
0200000
+ sha256sum spi_read
4bda3a28f4ffe603c0ec1258c0034d65a1a0d35ab7bd523a834608adabf03cc5  spi_read
+ mtd_debug write /dev/mtd0 0 2097152 spi_test
Copied 2097152 bytes from spi_test to address 0x00000000 in flash
+ mtd_debug read /dev/mtd0 0 2097152 spi_read
Copied 2097152 bytes from address 0x00000000 in flash to spi_read
+ sha256sum spi_read spi_test
c2712b5617a588f8bba4b8fc7af62f6ca5e2356577681b23544d1a93540ecd1d  spi_read
c2712b5617a588f8bba4b8fc7af62f6ca5e2356577681b23544d1a93540ecd1d  spi_test
+ mtd_debug erase /dev/mtd0 0 2097152
Erased 2097152 bytes from address 0x00000000 in flash
+ mtd_debug read /dev/mtd0 0 2097152 spi_read
Copied 2097152 bytes from address 0x00000000 in flash to spi_read
+ sha256sum spi_read spi_test
4bda3a28f4ffe603c0ec1258c0034d65a1a0d35ab7bd523a834608adabf03cc5  spi_read
c2712b5617a588f8bba4b8fc7af62f6ca5e2356577681b23544d1a93540ecd1d  spi_test
---
 drivers/mtd/spi-nor/winbond.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/spi-nor/winbond.c b/drivers/mtd/spi-nor/winbond.c
index 2114674de3dc..be8cc67eb72f 100644
--- a/drivers/mtd/spi-nor/winbond.c
+++ b/drivers/mtd/spi-nor/winbond.c
@@ -217,7 +217,7 @@ static const struct flash_info winbond_nor_parts[] = {
 		/* Flavors w/ and w/o SFDP. */
 		.name = "w25q128",
 		.size = SZ_16M,
-		.flags = SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB,
+		.flags = SPI_NOR_QUAD_PP | SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB,
 		.no_sfdp_flags = SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ,
 		.fixups = &w25q128_fixups,
 	}, {

-- 
2.54.0