[PATCH v7 4/7] mtd: spi-nor: sst: remove global protection flag

From: Michael Walle
Date: Wed Dec 02 2020 - 18:01:57 EST


This is considered bad for the following reasons:
(1) We only support the block protection with BPn bits for write
protection. Not all SST parts support this.
(2) Newly added flash chip will automatically inherit the "has
locking" support and thus needs to explicitly tested. Better
be opt-in instead of opt-out.
(3) There are already supported flashes which doesn't support
the locking scheme. So I assume this wasn't properly tested
before adding that chip; which enforces my previous argument
that locking support should be an opt-in.

Remove the global flag and add individual flags to all flashes
which supports BP locking. In particular the following flashes
don't support the BP scheme:
- SST26VF016B
- SST26WF016B
- SST26VF064B

Signed-off-by: Michael Walle <michael@xxxxxxxx>
Reviewed-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
---
changes since v6:
- none

changes since v5:
- none

changes since v4:
- none

changes since v3/v2/v1:
- there was no such version because this patch was bundled with another
patch

changes since RFC:
- none

drivers/mtd/spi-nor/sst.c | 30 ++++++++++++------------------
1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/drivers/mtd/spi-nor/sst.c b/drivers/mtd/spi-nor/sst.c
index 0ab07624fb73..0d9d319f61e6 100644
--- a/drivers/mtd/spi-nor/sst.c
+++ b/drivers/mtd/spi-nor/sst.c
@@ -11,27 +11,27 @@
static const struct flash_info sst_parts[] = {
/* SST -- large erase sizes are "overlays", "sectors" are 4K */
{ "sst25vf040b", INFO(0xbf258d, 0, 64 * 1024, 8,
- SECT_4K | SST_WRITE) },
+ SECT_4K | SST_WRITE | SPI_NOR_HAS_LOCK) },
{ "sst25vf080b", INFO(0xbf258e, 0, 64 * 1024, 16,
- SECT_4K | SST_WRITE) },
+ SECT_4K | SST_WRITE | SPI_NOR_HAS_LOCK) },
{ "sst25vf016b", INFO(0xbf2541, 0, 64 * 1024, 32,
- SECT_4K | SST_WRITE) },
+ SECT_4K | SST_WRITE | SPI_NOR_HAS_LOCK) },
{ "sst25vf032b", INFO(0xbf254a, 0, 64 * 1024, 64,
- SECT_4K | SST_WRITE) },
+ SECT_4K | SST_WRITE | SPI_NOR_HAS_LOCK) },
{ "sst25vf064c", INFO(0xbf254b, 0, 64 * 1024, 128,
- SECT_4K | SPI_NOR_4BIT_BP) },
+ SECT_4K | SPI_NOR_4BIT_BP | SPI_NOR_HAS_LOCK) },
{ "sst25wf512", INFO(0xbf2501, 0, 64 * 1024, 1,
- SECT_4K | SST_WRITE) },
+ SECT_4K | SST_WRITE | SPI_NOR_HAS_LOCK) },
{ "sst25wf010", INFO(0xbf2502, 0, 64 * 1024, 2,
- SECT_4K | SST_WRITE) },
+ SECT_4K | SST_WRITE | SPI_NOR_HAS_LOCK) },
{ "sst25wf020", INFO(0xbf2503, 0, 64 * 1024, 4,
- SECT_4K | SST_WRITE) },
- { "sst25wf020a", INFO(0x621612, 0, 64 * 1024, 4, SECT_4K) },
- { "sst25wf040b", INFO(0x621613, 0, 64 * 1024, 8, SECT_4K) },
+ SECT_4K | SST_WRITE | SPI_NOR_HAS_LOCK) },
+ { "sst25wf020a", INFO(0x621612, 0, 64 * 1024, 4, SECT_4K | SPI_NOR_HAS_LOCK) },
+ { "sst25wf040b", INFO(0x621613, 0, 64 * 1024, 8, SECT_4K | SPI_NOR_HAS_LOCK) },
{ "sst25wf040", INFO(0xbf2504, 0, 64 * 1024, 8,
- SECT_4K | SST_WRITE) },
+ SECT_4K | SST_WRITE | SPI_NOR_HAS_LOCK) },
{ "sst25wf080", INFO(0xbf2505, 0, 64 * 1024, 16,
- SECT_4K | SST_WRITE) },
+ SECT_4K | SST_WRITE | SPI_NOR_HAS_LOCK) },
{ "sst26wf016b", INFO(0xbf2651, 0, 64 * 1024, 32,
SECT_4K | SPI_NOR_DUAL_READ |
SPI_NOR_QUAD_READ) },
@@ -128,11 +128,6 @@ static int sst_write(struct mtd_info *mtd, loff_t to, size_t len,
return ret;
}

-static void sst_default_init(struct spi_nor *nor)
-{
- nor->flags |= SNOR_F_HAS_LOCK;
-}
-
static void sst_post_sfdp_fixups(struct spi_nor *nor)
{
if (nor->info->flags & SST_WRITE)
@@ -140,7 +135,6 @@ static void sst_post_sfdp_fixups(struct spi_nor *nor)
}

static const struct spi_nor_fixups sst_fixups = {
- .default_init = sst_default_init,
.post_sfdp = sst_post_sfdp_fixups,
};

--
2.20.1