diff mbox series

[1/2] docs: mtd: spi-nor: add sections about flash additions and testing

Message ID 20231123160721.64561-2-tudor.ambarus@linaro.org
State Superseded
Delegated to: Ambarus Tudor
Headers show
Series docs: mtd: spi-nor: add sections about flash additions and testing | expand

Commit Message

Tudor Ambarus Nov. 23, 2023, 4:07 p.m. UTC
Add sections about how to propose a new flash addition and about the
minimum testing requirements.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
---
 Documentation/driver-api/mtd/spi-nor.rst | 189 +++++++++++++++++++++++
 1 file changed, 189 insertions(+)

Comments

Michael Walle Nov. 23, 2023, 4:14 p.m. UTC | #1
Hi Tudor,

> Add sections about how to propose a new flash addition and about the
> minimum testing requirements.

Thanks for doing this :)

> Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
> ---
>  Documentation/driver-api/mtd/spi-nor.rst | 189 +++++++++++++++++++++++
>  1 file changed, 189 insertions(+)
> 
> diff --git a/Documentation/driver-api/mtd/spi-nor.rst 
> b/Documentation/driver-api/mtd/spi-nor.rst
> index c22f8c0f7950..cc8e81e09544 100644
> --- a/Documentation/driver-api/mtd/spi-nor.rst
> +++ b/Documentation/driver-api/mtd/spi-nor.rst
> @@ -63,3 +63,192 @@ The main API is spi_nor_scan(). Before you call the 
> hook, a driver should
>  initialize the necessary fields for spi_nor{}. Please see
>  drivers/mtd/spi-nor/spi-nor.c for detail. Please also refer to 
> spi-fsl-qspi.c
>  when you want to write a new driver for a SPI NOR controller.
> +
> +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.
> +
> +1/ 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.
> +
> +2/ Dump the sysfs entries and print the md5/sha1/sha256 SFDP 
> checksum::
> +
> +    root@1:~#  cat /sys/bus/spi/devices/spi1.0/spi-nor/partname
> +    sst26vf064b
> +    root@1:~#  cat /sys/bus/spi/devices/spi1.0/spi-nor/jedec_id
> +    bf2643
> +    root@1:~#  cat /sys/bus/spi/devices/spi1.0/spi-nor/manufacturer
> +    sst
> +    root@1:~# hexdump -C  /sys/bus/spi/devices/spi1.0/spi-nor/sfdp

Please use "xxd -p" (and maybe mention that if xxd is not available,
"hexdump -Cv" could be used instead). With xxd one can just use "xxd 
-rp"
to generate a binary again.

Otherwise looks good. So with the above fixed:

Reviewed-by: Michael Walle <michael@walle.cc>

> +    00000000  53 46 44 50 06 01 02 ff  00 06 01 10 30 00 00 ff  
> |SFDP........0...|
> +    00000010  81 00 01 06 00 01 00 ff  bf 00 01 18 00 02 00 01  
> |................|
> +    00000020  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  
> |................|
> +    00000030  fd 20 f1 ff ff ff ff 03  44 eb 08 6b 08 3b 80 bb  |. 
> ......D..k.;..|
> +    00000040  fe ff ff ff ff ff 00 ff  ff ff 44 0b 0c 20 0d d8  
> |..........D.. ..|
> +    00000050  0f d8 10 d8 20 91 48 24  80 6f 1d 81 ed 0f 77 38  |.... 
> .H$.o....w8|
> +    00000060  30 b0 30 b0 f7 ff ff ff  29 c2 5c ff f0 30 c0 80  
> |0.0.....).\..0..|
> +    00000070  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  
> |................|
> +    *
> +    00000100  ff 00 04 ff f3 7f 00 00  f5 7f 00 00 f9 ff 7d 00  
> |..............}.|
> +    00000110  f5 7f 00 00 f3 7f 00 00  ff ff ff ff ff ff ff ff  
> |................|
> +    00000120  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  
> |................|
> +    *
> +    00000200  bf 26 43 ff b9 5f fd ff  30 f2 60 f3 32 ff 0a 12  
> |.&C.._..0.`.2...|
> +    00000210  23 46 ff 0f 19 32 0f 19  19 ff ff ff ff ff ff ff  
> |#F...2..........|
> +    00000220  00 66 99 38 ff 05 01 35  06 04 02 32 b0 30 72 42  
> |.f.8...5...2.0rB|
> +    00000230  8d e8 98 88 a5 85 c0 9f  af 5a ff ff 06 ec 06 0c  
> |.........Z......|
> +    00000240  00 03 08 0b ff ff ff ff  ff 07 ff ff 02 02 ff 06  
> |................|
> +    00000250  03 00 fd fd 04 07 00 fc  03 00 fe fe 02 02 07 0e  
> |................|
> +    00000260
> +    root@1:~# sha256sum /sys/bus/spi/devices/spi1.0/spi-nor/sfdp
> +    428f34d0461876f189ac97f93e68a05fa6428c6650b3b7baf736a921e5898ed1  
> /sys/bus/spi/devices/spi1.0/spi-nor/sfdp
> +
> +3/ Dump debugfs data::
> +
> +    root@1:~# cat /sys/kernel/debug/spi-nor/spi1.0/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/spi1.0/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  ] |
> +
> +4/ Use `mtd-utils <https://git.infradead.org/mtd-utils.git>`__
> +and verify that erase, read and page program operations work fine.
> +
> +a/ Generate a 2 MB file::
> +
> +    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
> +
> +b/ Verify erase::
> +
> +    root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
> +    Copied 2097152 bytes from spi_test to address 0x00000000 in flash
> +
> +    root@1:~# mtd_debug erase /dev/mtd1 0 2097152
> +    Erased 2097152 bytes from address 0x00000000 in flash
> +
> +    root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
> +    Copied 2097152 bytes from address 0x00000000 in flash to spi_read
> +
> +    root@1:~# hexdump -C spi_read
> +    00000000  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  
> |................|
> +    *
> +    00200000
> +
> +c/ Write, read back and compare::
> +
> +    root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
> +    Copied 2097152 bytes from spi_test to address 0x00000000 in flash
> +
> +    root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
> +    Copied 2097152 bytes from address 0x00000000 in flash to spi_read
> +
> +    root@1:~# sha1sum spi_*
> +    51eeddc316a4121cf96e76e526d94d638283ec22  spi_read
> +    51eeddc316a4121cf96e76e526d94d638283ec22  spi_test
> +
> +d/ Dump mtd_info data::
> +
> +    root@1:~# mtd_debug info /dev/mtd1
> +    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
Bagas Sanjaya Nov. 24, 2023, 7:12 a.m. UTC | #2
On Thu, Nov 23, 2023 at 06:07:20PM +0200, Tudor Ambarus wrote:
> +Minimum testing requirements
> +-----------------------------
> +
> +Do all the tests from below and paste them in the commit's comments
> +section, after the ``---`` marker.
> +
> +1/ 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.
> +
> +2/ Dump the sysfs entries and print the md5/sha1/sha256 SFDP checksum::
> +
> +    root@1:~#  cat /sys/bus/spi/devices/spi1.0/spi-nor/partname
> +    sst26vf064b
> +    root@1:~#  cat /sys/bus/spi/devices/spi1.0/spi-nor/jedec_id
> +    bf2643
> +    root@1:~#  cat /sys/bus/spi/devices/spi1.0/spi-nor/manufacturer
> +    sst
> +    root@1:~# hexdump -C  /sys/bus/spi/devices/spi1.0/spi-nor/sfdp
> +    00000000  53 46 44 50 06 01 02 ff  00 06 01 10 30 00 00 ff  |SFDP........0...|
> +    00000010  81 00 01 06 00 01 00 ff  bf 00 01 18 00 02 00 01  |................|
> +    00000020  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
> +    00000030  fd 20 f1 ff ff ff ff 03  44 eb 08 6b 08 3b 80 bb  |. ......D..k.;..|
> +    00000040  fe ff ff ff ff ff 00 ff  ff ff 44 0b 0c 20 0d d8  |..........D.. ..|
> +    00000050  0f d8 10 d8 20 91 48 24  80 6f 1d 81 ed 0f 77 38  |.... .H$.o....w8|
> +    00000060  30 b0 30 b0 f7 ff ff ff  29 c2 5c ff f0 30 c0 80  |0.0.....).\..0..|
> +    00000070  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
> +    *
> +    00000100  ff 00 04 ff f3 7f 00 00  f5 7f 00 00 f9 ff 7d 00  |..............}.|
> +    00000110  f5 7f 00 00 f3 7f 00 00  ff ff ff ff ff ff ff ff  |................|
> +    00000120  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
> +    *
> +    00000200  bf 26 43 ff b9 5f fd ff  30 f2 60 f3 32 ff 0a 12  |.&C.._..0.`.2...|
> +    00000210  23 46 ff 0f 19 32 0f 19  19 ff ff ff ff ff ff ff  |#F...2..........|
> +    00000220  00 66 99 38 ff 05 01 35  06 04 02 32 b0 30 72 42  |.f.8...5...2.0rB|
> +    00000230  8d e8 98 88 a5 85 c0 9f  af 5a ff ff 06 ec 06 0c  |.........Z......|
> +    00000240  00 03 08 0b ff ff ff ff  ff 07 ff ff 02 02 ff 06  |................|
> +    00000250  03 00 fd fd 04 07 00 fc  03 00 fe fe 02 02 07 0e  |................|
> +    00000260
> +    root@1:~# sha256sum /sys/bus/spi/devices/spi1.0/spi-nor/sfdp
> +    428f34d0461876f189ac97f93e68a05fa6428c6650b3b7baf736a921e5898ed1  /sys/bus/spi/devices/spi1.0/spi-nor/sfdp
> +
> +3/ Dump debugfs data::
> +
> +    root@1:~# cat /sys/kernel/debug/spi-nor/spi1.0/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/spi1.0/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  ] |
> +
> +4/ Use `mtd-utils <https://git.infradead.org/mtd-utils.git>`__
> +and verify that erase, read and page program operations work fine.
> +
> +a/ Generate a 2 MB file::
> +
> +    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
> +
> +b/ Verify erase::
> +
> +    root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
> +    Copied 2097152 bytes from spi_test to address 0x00000000 in flash
> +
> +    root@1:~# mtd_debug erase /dev/mtd1 0 2097152
> +    Erased 2097152 bytes from address 0x00000000 in flash
> +
> +    root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
> +    Copied 2097152 bytes from address 0x00000000 in flash to spi_read
> +
> +    root@1:~# hexdump -C spi_read
> +    00000000  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
> +    *
> +    00200000
> +
> +c/ Write, read back and compare::
> +
> +    root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
> +    Copied 2097152 bytes from spi_test to address 0x00000000 in flash
> +
> +    root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
> +    Copied 2097152 bytes from address 0x00000000 in flash to spi_read
> +
> +    root@1:~# sha1sum spi_*
> +    51eeddc316a4121cf96e76e526d94d638283ec22  spi_read
> +    51eeddc316a4121cf96e76e526d94d638283ec22  spi_test
> +
> +d/ Dump mtd_info data::
> +
> +    root@1:~# mtd_debug info /dev/mtd1
> +    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

The numbered lists don't properly rendered, so I have to fix it up:

---- >8 ----
diff --git a/Documentation/driver-api/mtd/spi-nor.rst b/Documentation/driver-api/mtd/spi-nor.rst
index 7a8737fe181de5..d482658628b3c0 100644
--- a/Documentation/driver-api/mtd/spi-nor.rst
+++ b/Documentation/driver-api/mtd/spi-nor.rst
@@ -30,13 +30,13 @@ Minimum testing requirements
 Do all the tests from below and paste them in the commit's comments
 section, after the ``---`` marker.
 
-1/ Specify the controller that you used to test the flash and specify
-the frequency at which the flash was operated::
+1) Specify the controller that you used to test the flash and specify
+   the frequency at which the flash was operated, e.g.::
 
-    E.g. This flash is populated on the X board and was tested at Y
+    This flash is populated on the X board and was tested at Y
     frequency using the Z (put compatible) SPI controller.
 
-2/ Dump the sysfs entries and print the md5/sha1/sha256 SFDP checksum::
+2) Dump the sysfs entries and print the md5/sha1/sha256 SFDP checksum::
 
     root@1:~#  cat /sys/bus/spi/devices/spi1.0/spi-nor/partname
     sst26vf064b
@@ -68,7 +68,7 @@ the frequency at which the flash was operated::
     root@1:~# sha256sum /sys/bus/spi/devices/spi1.0/spi-nor/sfdp
     428f34d0461876f189ac97f93e68a05fa6428c6650b3b7baf736a921e5898ed1  /sys/bus/spi/devices/spi1.0/spi-nor/sfdp
 
-3/ Dump debugfs data::
+3) Dump debugfs data::
 
     root@1:~# cat /sys/kernel/debug/spi-nor/spi1.0/capabilities
     Supported read modes by the flash
@@ -142,51 +142,51 @@ the frequency at which the flash was operated::
      007f0000-007f7fff |     [0 2 ] |
      007f8000-007fffff |     [01  ] |
 
-4/ Use `mtd-utils <https://git.infradead.org/mtd-utils.git>`__
-and verify that erase, read and page program operations work fine.
+4) Use `mtd-utils <https://git.infradead.org/mtd-utils.git>`__
+and verify that erase, read and page program operations work fine:
 
-a/ Generate a 2 MB file::
+   a) Generate a 2 MB file::
 
-    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:~# 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
 
-b/ Verify erase::
+   b) Verify erase::
 
-    root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
-    Copied 2097152 bytes from spi_test to address 0x00000000 in flash
+       root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
+       Copied 2097152 bytes from spi_test to address 0x00000000 in flash
 
-    root@1:~# mtd_debug erase /dev/mtd1 0 2097152
-    Erased 2097152 bytes from address 0x00000000 in flash
+       root@1:~# mtd_debug erase /dev/mtd1 0 2097152
+       Erased 2097152 bytes from address 0x00000000 in flash
 
-    root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
-    Copied 2097152 bytes from address 0x00000000 in flash to spi_read
+       root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
+       Copied 2097152 bytes from address 0x00000000 in flash to spi_read
 
-    root@1:~# hexdump -C spi_read
-    00000000  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
-    *
-    00200000
+       root@1:~# hexdump -C spi_read
+       00000000  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
+       *
+       00200000
 
-c/ Write, read back and compare::
+   c) Write, read back and compare::
 
-    root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
-    Copied 2097152 bytes from spi_test to address 0x00000000 in flash
+       root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
+       Copied 2097152 bytes from spi_test to address 0x00000000 in flash
 
-    root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
-    Copied 2097152 bytes from address 0x00000000 in flash to spi_read
+       root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
+       Copied 2097152 bytes from address 0x00000000 in flash to spi_read
 
-    root@1:~# sha1sum spi_*
-    51eeddc316a4121cf96e76e526d94d638283ec22  spi_read
-    51eeddc316a4121cf96e76e526d94d638283ec22  spi_test
+       root@1:~# sha1sum spi_*
+       51eeddc316a4121cf96e76e526d94d638283ec22  spi_read
+       51eeddc316a4121cf96e76e526d94d638283ec22  spi_test
 
-d/ Dump mtd_info data::
+   d) Dump mtd_info data::
 
-    root@1:~# mtd_debug info /dev/mtd1
-    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
+       root@1:~# mtd_debug info /dev/mtd1
+       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

Thanks.
Pratyush Yadav Nov. 24, 2023, 2:36 p.m. UTC | #3
Hi,


On Thu, Nov 23 2023, Tudor Ambarus wrote:

> Add sections about how to propose a new flash addition and about the
> minimum testing requirements.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
> ---
>  Documentation/driver-api/mtd/spi-nor.rst | 189 +++++++++++++++++++++++
>  1 file changed, 189 insertions(+)
>
> diff --git a/Documentation/driver-api/mtd/spi-nor.rst b/Documentation/driver-api/mtd/spi-nor.rst
> index c22f8c0f7950..cc8e81e09544 100644
> --- a/Documentation/driver-api/mtd/spi-nor.rst
> +++ b/Documentation/driver-api/mtd/spi-nor.rst
> @@ -63,3 +63,192 @@ The main API is spi_nor_scan(). Before you call the hook, a driver should
>  initialize the necessary fields for spi_nor{}. Please see
>  drivers/mtd/spi-nor/spi-nor.c for detail. Please also refer to spi-fsl-qspi.c
>  when you want to write a new driver for a SPI NOR controller.
[...]
> +4/ Use `mtd-utils <https://git.infradead.org/mtd-utils.git>`__
> +and verify that erase, read and page program operations work fine.
> +
> +a/ Generate a 2 MB file::
> +
> +    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
> +
> +b/ Verify erase::
> +
> +    root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
> +    Copied 2097152 bytes from spi_test to address 0x00000000 in flash

Perhaps mention that the 2 MiB region should already be erased.
Otherwise some flashes might refuse the writes (like the ones with ECC
-- Cypress S28 family comes to mind). Experienced engineers should know
this already but it might trip up some beginners.

Looks good otherwise. Thanks for working on this.

Reviewed-by: Pratyush Yadav <pratyush@kernel.org>

> +
> +    root@1:~# mtd_debug erase /dev/mtd1 0 2097152
> +    Erased 2097152 bytes from address 0x00000000 in flash
> +
> +    root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
> +    Copied 2097152 bytes from address 0x00000000 in flash to spi_read
> +
> +    root@1:~# hexdump -C spi_read
> +    00000000  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
> +    *
> +    00200000
> +
[...]
Tudor Ambarus Nov. 24, 2023, 3:57 p.m. UTC | #4
On 11/24/23 14:36, Pratyush Yadav wrote:
> Hi,
> 
> 
> On Thu, Nov 23 2023, Tudor Ambarus wrote:
> 
>> Add sections about how to propose a new flash addition and about the
>> minimum testing requirements.
>>
>> Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
>> ---
>>  Documentation/driver-api/mtd/spi-nor.rst | 189 +++++++++++++++++++++++
>>  1 file changed, 189 insertions(+)
>>
>> diff --git a/Documentation/driver-api/mtd/spi-nor.rst b/Documentation/driver-api/mtd/spi-nor.rst
>> index c22f8c0f7950..cc8e81e09544 100644
>> --- a/Documentation/driver-api/mtd/spi-nor.rst
>> +++ b/Documentation/driver-api/mtd/spi-nor.rst
>> @@ -63,3 +63,192 @@ The main API is spi_nor_scan(). Before you call the hook, a driver should
>>  initialize the necessary fields for spi_nor{}. Please see
>>  drivers/mtd/spi-nor/spi-nor.c for detail. Please also refer to spi-fsl-qspi.c
>>  when you want to write a new driver for a SPI NOR controller.
> [...]
>> +4/ Use `mtd-utils <https://git.infradead.org/mtd-utils.git>`__
>> +and verify that erase, read and page program operations work fine.
>> +
>> +a/ Generate a 2 MB file::
>> +
>> +    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
>> +
>> +b/ Verify erase::
>> +
>> +    root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
>> +    Copied 2097152 bytes from spi_test to address 0x00000000 in flash
> 
> Perhaps mention that the 2 MiB region should already be erased.
> Otherwise some flashes might refuse the writes (like the ones with ECC

right, then maybe we could do a

/erase
/read
/dump and see 0xff
/sha1sum to have the 0xff checksum
/write
/read what was written
/sha1sum on the read to make it's different that the 0xff checksum and
that the write worked

> -- Cypress S28 family comes to mind). Experienced engineers should know
> this already but it might trip up some beginners.
> 
> Looks good otherwise. Thanks for working on this.
> 
> Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
> 
>> +
>> +    root@1:~# mtd_debug erase /dev/mtd1 0 2097152
>> +    Erased 2097152 bytes from address 0x00000000 in flash
>> +
>> +    root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
>> +    Copied 2097152 bytes from address 0x00000000 in flash to spi_read
>> +
>> +    root@1:~# hexdump -C spi_read
>> +    00000000  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
>> +    *
>> +    00200000
>> +
> [...]
>
Tudor Ambarus Nov. 24, 2023, 5:01 p.m. UTC | #5
On 24.11.2023 09:12, Bagas Sanjaya wrote:
> The numbered lists don't properly rendered, so I have to fix it up:

Thanks, Bagas! It looks better, indeed. I'll include the diff in the
next version.

Cheers,
ta
diff mbox series

Patch

diff --git a/Documentation/driver-api/mtd/spi-nor.rst b/Documentation/driver-api/mtd/spi-nor.rst
index c22f8c0f7950..cc8e81e09544 100644
--- a/Documentation/driver-api/mtd/spi-nor.rst
+++ b/Documentation/driver-api/mtd/spi-nor.rst
@@ -63,3 +63,192 @@  The main API is spi_nor_scan(). Before you call the hook, a driver should
 initialize the necessary fields for spi_nor{}. Please see
 drivers/mtd/spi-nor/spi-nor.c for detail. Please also refer to spi-fsl-qspi.c
 when you want to write a new driver for a SPI NOR controller.
+
+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.
+
+1/ 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.
+
+2/ Dump the sysfs entries and print the md5/sha1/sha256 SFDP checksum::
+
+    root@1:~#  cat /sys/bus/spi/devices/spi1.0/spi-nor/partname
+    sst26vf064b
+    root@1:~#  cat /sys/bus/spi/devices/spi1.0/spi-nor/jedec_id
+    bf2643
+    root@1:~#  cat /sys/bus/spi/devices/spi1.0/spi-nor/manufacturer
+    sst
+    root@1:~# hexdump -C  /sys/bus/spi/devices/spi1.0/spi-nor/sfdp
+    00000000  53 46 44 50 06 01 02 ff  00 06 01 10 30 00 00 ff  |SFDP........0...|
+    00000010  81 00 01 06 00 01 00 ff  bf 00 01 18 00 02 00 01  |................|
+    00000020  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
+    00000030  fd 20 f1 ff ff ff ff 03  44 eb 08 6b 08 3b 80 bb  |. ......D..k.;..|
+    00000040  fe ff ff ff ff ff 00 ff  ff ff 44 0b 0c 20 0d d8  |..........D.. ..|
+    00000050  0f d8 10 d8 20 91 48 24  80 6f 1d 81 ed 0f 77 38  |.... .H$.o....w8|
+    00000060  30 b0 30 b0 f7 ff ff ff  29 c2 5c ff f0 30 c0 80  |0.0.....).\..0..|
+    00000070  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
+    *
+    00000100  ff 00 04 ff f3 7f 00 00  f5 7f 00 00 f9 ff 7d 00  |..............}.|
+    00000110  f5 7f 00 00 f3 7f 00 00  ff ff ff ff ff ff ff ff  |................|
+    00000120  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
+    *
+    00000200  bf 26 43 ff b9 5f fd ff  30 f2 60 f3 32 ff 0a 12  |.&C.._..0.`.2...|
+    00000210  23 46 ff 0f 19 32 0f 19  19 ff ff ff ff ff ff ff  |#F...2..........|
+    00000220  00 66 99 38 ff 05 01 35  06 04 02 32 b0 30 72 42  |.f.8...5...2.0rB|
+    00000230  8d e8 98 88 a5 85 c0 9f  af 5a ff ff 06 ec 06 0c  |.........Z......|
+    00000240  00 03 08 0b ff ff ff ff  ff 07 ff ff 02 02 ff 06  |................|
+    00000250  03 00 fd fd 04 07 00 fc  03 00 fe fe 02 02 07 0e  |................|
+    00000260
+    root@1:~# sha256sum /sys/bus/spi/devices/spi1.0/spi-nor/sfdp
+    428f34d0461876f189ac97f93e68a05fa6428c6650b3b7baf736a921e5898ed1  /sys/bus/spi/devices/spi1.0/spi-nor/sfdp
+
+3/ Dump debugfs data::
+
+    root@1:~# cat /sys/kernel/debug/spi-nor/spi1.0/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/spi1.0/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  ] |
+
+4/ Use `mtd-utils <https://git.infradead.org/mtd-utils.git>`__
+and verify that erase, read and page program operations work fine.
+
+a/ Generate a 2 MB file::
+
+    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
+
+b/ Verify erase::
+
+    root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
+    Copied 2097152 bytes from spi_test to address 0x00000000 in flash
+
+    root@1:~# mtd_debug erase /dev/mtd1 0 2097152
+    Erased 2097152 bytes from address 0x00000000 in flash
+
+    root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
+    Copied 2097152 bytes from address 0x00000000 in flash to spi_read
+
+    root@1:~# hexdump -C spi_read
+    00000000  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
+    *
+    00200000
+
+c/ Write, read back and compare::
+
+    root@1:~# mtd_debug write /dev/mtd1 0 2097152 spi_test
+    Copied 2097152 bytes from spi_test to address 0x00000000 in flash
+
+    root@1:~# mtd_debug read /dev/mtd1 0 2097152 spi_read
+    Copied 2097152 bytes from address 0x00000000 in flash to spi_read
+
+    root@1:~# sha1sum spi_*
+    51eeddc316a4121cf96e76e526d94d638283ec22  spi_read
+    51eeddc316a4121cf96e76e526d94d638283ec22  spi_test
+
+d/ Dump mtd_info data::
+
+    root@1:~# mtd_debug info /dev/mtd1
+    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