SPI NOR framework¶
How to propose a new flash addition¶
Most SPI NOR flashes comply with the JEDEC JESD216 Serial Flash Discoverable Parameter (SFDP) standard. SFDP describes the functional and feature capabilities of serial flash devices in a standard set of internal read-only parameter tables.
The SPI NOR driver queries the SFDP tables in order to determine the flash's parameters and settings. If the flash defines the SFDP tables it's likely that you won't need a flash entry at all, and instead rely on the generic flash driver which probes the flash solely based on its SFDP data. All one has to do is to specify the "jedec,spi-nor" compatible in the device tree.
There are cases however where you need to define an explicit flash
entry. This typically happens when the flash has settings or support
that is not covered by the SFDP tables (e.g. Block Protection), or
when the flash contains mangled SFDP data. If the later, one needs
to implement the spi_nor_fixups
hooks in order to amend the SFDP
parameters with the correct values.
Minimum testing requirements¶
Do all the tests from below and paste them in the commit's comments
section, after the ---
marker.
Specify the controller that you used to test the flash and specify the frequency at which the flash was operated, e.g.:
This flash is populated on the X board and was tested at Y frequency using the Z (put compatible) SPI controller.
Dump the sysfs entries and print the md5/sha1/sha256 SFDP checksum:
root@1:~# cat /sys/bus/spi/devices/spi0.0/spi-nor/partname sst26vf064b root@1:~# cat /sys/bus/spi/devices/spi0.0/spi-nor/jedec_id bf2643 root@1:~# cat /sys/bus/spi/devices/spi0.0/spi-nor/manufacturer sst root@1:~# xxd -p /sys/bus/spi/devices/spi0.0/spi-nor/sfdp 53464450060102ff00060110300000ff81000106000100ffbf0001180002 0001fffffffffffffffffffffffffffffffffd20f1ffffffff0344eb086b 083b80bbfeffffffffff00ffffff440b0c200dd80fd810d820914824806f 1d81ed0f773830b030b0f7ffffff29c25cfff030c080ffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffff0004fff37f0000f57f0000f9ff 7d00f57f0000f37f0000ffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff ffffbf2643ffb95ffdff30f260f332ff0a122346ff0f19320f1919ffffff ffffffff00669938ff05013506040232b03072428de89888a585c09faf5a ffff06ec060c0003080bffffffffff07ffff0202ff060300fdfd040700fc 0300fefe0202070e root@1:~# sha256sum /sys/bus/spi/devices/spi0.0/spi-nor/sfdp 428f34d0461876f189ac97f93e68a05fa6428c6650b3b7baf736a921e5898ed1 /sys/bus/spi/devices/spi0.0/spi-nor/sfdp
Please dump the SFDP tables using
xxd -p
. It enables us to do the reverse operation and convert the hexdump to binary withxxd -rp
. Dumping the SFDP data withhexdump -Cv
is accepted, but less desirable.Dump debugfs data:
root@1:~# cat /sys/kernel/debug/spi-nor/spi0.0/capabilities Supported read modes by the flash 1S-1S-1S opcode 0x03 mode cycles 0 dummy cycles 0 1S-1S-1S (fast read) opcode 0x0b mode cycles 0 dummy cycles 8 1S-1S-2S opcode 0x3b mode cycles 0 dummy cycles 8 1S-2S-2S opcode 0xbb mode cycles 4 dummy cycles 0 1S-1S-4S opcode 0x6b mode cycles 0 dummy cycles 8 1S-4S-4S opcode 0xeb mode cycles 2 dummy cycles 4 4S-4S-4S opcode 0x0b mode cycles 2 dummy cycles 4 Supported page program modes by the flash 1S-1S-1S opcode 0x02 root@1:~# cat /sys/kernel/debug/spi-nor/spi0.0/params name sst26vf064b id bf 26 43 bf 26 43 size 8.00 MiB write size 1 page size 256 address nbytes 3 flags HAS_LOCK | HAS_16BIT_SR | SOFT_RESET | SWP_IS_VOLATILE opcodes read 0xeb dummy cycles 6 erase 0x20 program 0x02 8D extension none protocols read 1S-4S-4S write 1S-1S-1S register 1S-1S-1S erase commands 20 (4.00 KiB) [0] d8 (8.00 KiB) [1] d8 (32.0 KiB) [2] d8 (64.0 KiB) [3] c7 (8.00 MiB) sector map region (in hex) | erase mask | flags ------------------+------------+---------- 00000000-00007fff | [01 ] | 00008000-0000ffff | [0 2 ] | 00010000-007effff | [0 3] | 007f0000-007f7fff | [0 2 ] | 007f8000-007fffff | [01 ] |
Use mtd-utils and verify that erase, read and page program operations work fine:
root@1:~# dd if=/dev/urandom of=./spi_test bs=1M count=2 2+0 records in 2+0 records out 2097152 bytes (2.1 MB, 2.0 MiB) copied, 0.848566 s, 2.5 MB/s root@1:~# mtd_debug erase /dev/mtd0 0 2097152 Erased 2097152 bytes from address 0x00000000 in flash root@1:~# mtd_debug read /dev/mtd0 0 2097152 spi_read Copied 2097152 bytes from address 0x00000000 in flash to spi_read root@1:~# hexdump spi_read 0000000 ffff ffff ffff ffff ffff ffff ffff ffff * 0200000 root@1:~# sha256sum spi_read 4bda3a28f4ffe603c0ec1258c0034d65a1a0d35ab7bd523a834608adabf03cc5 spi_read root@1:~# mtd_debug write /dev/mtd0 0 2097152 spi_test Copied 2097152 bytes from spi_test to address 0x00000000 in flash root@1:~# mtd_debug read /dev/mtd0 0 2097152 spi_read Copied 2097152 bytes from address 0x00000000 in flash to spi_read root@1:~# sha256sum spi* c444216a6ba2a4a66cccd60a0dd062bce4b865dd52b200ef5e21838c4b899ac8 spi_read c444216a6ba2a4a66cccd60a0dd062bce4b865dd52b200ef5e21838c4b899ac8 spi_test
If the flash comes erased by default and the previous erase was ignored, we won't catch it, thus test the erase again:
root@1:~# mtd_debug erase /dev/mtd0 0 2097152 Erased 2097152 bytes from address 0x00000000 in flash root@1:~# mtd_debug read /dev/mtd0 0 2097152 spi_read Copied 2097152 bytes from address 0x00000000 in flash to spi_read root@1:~# sha256sum spi* 4bda3a28f4ffe603c0ec1258c0034d65a1a0d35ab7bd523a834608adabf03cc5 spi_read c444216a6ba2a4a66cccd60a0dd062bce4b865dd52b200ef5e21838c4b899ac8 spi_test
Dump some other relevant data:
root@1:~# mtd_debug info /dev/mtd0 mtd.type = MTD_NORFLASH mtd.flags = MTD_CAP_NORFLASH mtd.size = 8388608 (8M) mtd.erasesize = 4096 (4K) mtd.writesize = 1 mtd.oobsize = 0 regions = 0