[PATCH v3 1/2] mtd: spi-nor: issi: is25wp256: Init flash based on SFDP

[Sudip Mukherjee]

On Tue, Sep 20, 2022 at 7:48 PM Sudip Mukherjee
<sudip.mukherjee at sifive.com> wrote:
>
> The datasheet of is25wp256 says it supports SFDP. Get rid of the static
> initialization of the flash parameters and init them when parsing SFDP.
>
> Testing showed the flash using SPINOR_OP_READ_1_1_4_4B 0x6c,
> SPINOR_OP_PP_4B 0x12 and SPINOR_OP_BE_4K_4B 0x21 before enabling SFDP.
> After this patch, it parses the SFDP information and still uses the
> same opcodes.
>
> Signed-off-by: Sudip Mukherjee <sudip.mukherjee at sifive.com>
> ---
>
> No change from v2, just resending again with the next patch.
> Results from the tests given by Tudor in the following mail.

Test result after this patch:

# dd if=/dev/urandom of=./qspi_test bs=1M count=6
6+0 records in
6+0 records out

# mtd_debug write /dev/mtd4 0 6291456 qspi_test
Copied 6291456 bytes from qspi_test to address 0x00000000 in flash

# mtd_debug erase /dev/mtd4 0 6291456
Erased 6291456 bytes from address 0x00000000 in flash

# mtd_debug read /dev/mtd4 0 6291456 qspi_read
Copied 6291456 bytes from address 0x00000000 in flash to qspi_read

# hexdump qspi_read
0000000 ffff ffff ffff ffff ffff ffff ffff ffff
*

0600000

# mtd_debug write /dev/mtd4 0 6291456 qspi_test
Copied 6291456 bytes from qspi_test to address 0x00000000 in flash

# mtd_debug read /dev/mtd4 0 6291456 qspi_read
Copied 6291456 bytes from address 0x00000000 in flash to qspi_read

# sha1sum qspi_test qspi_read
57f8d4fee65622104e24276e865f662844f12242  qspi_test
57f8d4fee65622104e24276e865f662844f12242  qspi_read

# cat /sys/bus/spi/devices/spi0.0/spi-nor/partname
is25wp256

# cat /sys/bus/spi/devices/spi0.0/spi-nor/jedec_id
9d7019

# cat /sys/bus/spi/devices/spi0.0/spi-nor/manufacturer
issi

# xxd -p /sys/bus/spi/devices/spi0.0/spi-nor/sfdp
53464450060101ff00060110300000ff9d05010380000002ffffffffffff
ffffffffffffffffffffffffffffffffffffe520f9ffffffff0f44eb086b
083b80bbfeffffffffff00ffffff44eb0c200f5210d800ff234ac90082d8
11cecccd68467a757a75f7aed55c4a422cfff030faa9ffffffffffffffff
ffffffffffffffff501950169ff9c0648fefffff

# md5sum /sys/bus/spi/devices/spi0.0/spi-nor/sfdp
ba14818b9ec42713f24d94d66bb90ba0  /sys/bus/spi/devices/spi0.0/spi-nor/sfdp


-- 
Regards
Sudip