1 ================= 2 SPI NOR framework 3 ================= 4 5 How to propose a new flash addition 6 ----------------------------------- 7 8 Most SPI NOR flashes comply with the JEDEC JESD216 9 Serial Flash Discoverable Parameter (SFDP) standard. SFDP describes 10 the functional and feature capabilities of serial flash devices in a 11 standard set of internal read-only parameter tables. 12 13 The SPI NOR driver queries the SFDP tables in order to determine the 14 flash's parameters and settings. If the flash defines the SFDP tables 15 it's likely that you won't need a flash entry at all, and instead 16 rely on the generic flash driver which probes the flash solely based 17 on its SFDP data. All one has to do is to specify the "jedec,spi-nor" 18 compatible in the device tree. 19 20 There are cases however where you need to define an explicit flash 21 entry. This typically happens when the flash has settings or support 22 that is not covered by the SFDP tables (e.g. Block Protection), or 23 when the flash contains mangled SFDP data. If the later, one needs 24 to implement the ``spi_nor_fixups`` hooks in order to amend the SFDP 25 parameters with the correct values. 26 27 Minimum testing requirements 28 ----------------------------- 29 30 Do all the tests from below and paste them in the commit's comments 31 section, after the ``---`` marker. 32 33 1) Specify the controller that you used to test the flash and specify 34 the frequency at which the flash was operated, e.g.:: 35 36 This flash is populated on the X board and was tested at Y 37 frequency using the Z (put compatible) SPI controller. 38 39 2) Dump the sysfs entries and print the md5/sha1/sha256 SFDP checksum:: 40 41 root@1:~# cat /sys/bus/spi/devices/spi0.0/spi-nor/partname 42 sst26vf064b 43 root@1:~# cat /sys/bus/spi/devices/spi0.0/spi-nor/jedec_id 44 bf2643 45 root@1:~# cat /sys/bus/spi/devices/spi0.0/spi-nor/manufacturer 46 sst 47 root@1:~# xxd -p /sys/bus/spi/devices/spi0.0/spi-nor/sfdp 48 53464450060102ff00060110300000ff81000106000100ffbf0001180002 49 0001fffffffffffffffffffffffffffffffffd20f1ffffffff0344eb086b 50 083b80bbfeffffffffff00ffffff440b0c200dd80fd810d820914824806f 51 1d81ed0f773830b030b0f7ffffff29c25cfff030c080ffffffffffffffff 52 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 53 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 54 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 55 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 56 ffffffffffffffffffffffffffffffffff0004fff37f0000f57f0000f9ff 57 7d00f57f0000f37f0000ffffffffffffffffffffffffffffffffffffffff 58 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 59 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 60 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 61 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 62 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 63 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 64 ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff 65 ffffbf2643ffb95ffdff30f260f332ff0a122346ff0f19320f1919ffffff 66 ffffffff00669938ff05013506040232b03072428de89888a585c09faf5a 67 ffff06ec060c0003080bffffffffff07ffff0202ff060300fdfd040700fc 68 0300fefe0202070e 69 root@1:~# sha256sum /sys/bus/spi/devices/spi0.0/spi-nor/sfdp 70 428f34d0461876f189ac97f93e68a05fa6428c6650b3b7baf736a921e5898ed1 /sys/bus/spi/devices/spi0.0/spi-nor/sfdp 71 72 Please dump the SFDP tables using ``xxd -p``. It enables us to do 73 the reverse operation and convert the hexdump to binary with 74 ``xxd -rp``. Dumping the SFDP data with ``hexdump -Cv`` is accepted, 75 but less desirable. 76 77 3) Dump debugfs data:: 78 79 root@1:~# cat /sys/kernel/debug/spi-nor/spi0.0/capabilities 80 Supported read modes by the flash 81 1S-1S-1S 82 opcode 0x03 83 mode cycles 0 84 dummy cycles 0 85 1S-1S-1S (fast read) 86 opcode 0x0b 87 mode cycles 0 88 dummy cycles 8 89 1S-1S-2S 90 opcode 0x3b 91 mode cycles 0 92 dummy cycles 8 93 1S-2S-2S 94 opcode 0xbb 95 mode cycles 4 96 dummy cycles 0 97 1S-1S-4S 98 opcode 0x6b 99 mode cycles 0 100 dummy cycles 8 101 1S-4S-4S 102 opcode 0xeb 103 mode cycles 2 104 dummy cycles 4 105 4S-4S-4S 106 opcode 0x0b 107 mode cycles 2 108 dummy cycles 4 109 110 Supported page program modes by the flash 111 1S-1S-1S 112 opcode 0x02 113 114 root@1:~# cat /sys/kernel/debug/spi-nor/spi0.0/params 115 name sst26vf064b 116 id bf 26 43 bf 26 43 117 size 8.00 MiB 118 write size 1 119 page size 256 120 address nbytes 3 121 flags HAS_LOCK | HAS_16BIT_SR | SOFT_RESET | SWP_IS_VOLATILE 122 123 opcodes 124 read 0xeb 125 dummy cycles 6 126 erase 0x20 127 program 0x02 128 8D extension none 129 130 protocols 131 read 1S-4S-4S 132 write 1S-1S-1S 133 register 1S-1S-1S 134 135 erase commands 136 20 (4.00 KiB) [0] 137 d8 (8.00 KiB) [1] 138 d8 (32.0 KiB) [2] 139 d8 (64.0 KiB) [3] 140 c7 (8.00 MiB) 141 142 sector map 143 region (in hex) | erase mask | flags 144 ------------------+------------+---------- 145 00000000-00007fff | [01 ] | 146 00008000-0000ffff | [0 2 ] | 147 00010000-007effff | [0 3] | 148 007f0000-007f7fff | [0 2 ] | 149 007f8000-007fffff | [01 ] | 150 151 4) Use `mtd-utils <https://git.infradead.org/mtd-utils.git>`__ 152 and verify that erase, read and page program operations work fine:: 153 154 root@1:~# dd if=/dev/urandom of=./spi_test bs=1M count=2 155 2+0 records in 156 2+0 records out 157 2097152 bytes (2.1 MB, 2.0 MiB) copied, 0.848566 s, 2.5 MB/s 158 159 root@1:~# mtd_debug erase /dev/mtd0 0 2097152 160 Erased 2097152 bytes from address 0x00000000 in flash 161 162 root@1:~# mtd_debug read /dev/mtd0 0 2097152 spi_read 163 Copied 2097152 bytes from address 0x00000000 in flash to spi_read 164 165 root@1:~# hexdump spi_read 166 0000000 ffff ffff ffff ffff ffff ffff ffff ffff 167 * 168 0200000 169 170 root@1:~# sha256sum spi_read 171 4bda3a28f4ffe603c0ec1258c0034d65a1a0d35ab7bd523a834608adabf03cc5 spi_read 172 173 root@1:~# mtd_debug write /dev/mtd0 0 2097152 spi_test 174 Copied 2097152 bytes from spi_test to address 0x00000000 in flash 175 176 root@1:~# mtd_debug read /dev/mtd0 0 2097152 spi_read 177 Copied 2097152 bytes from address 0x00000000 in flash to spi_read 178 179 root@1:~# sha256sum spi* 180 c444216a6ba2a4a66cccd60a0dd062bce4b865dd52b200ef5e21838c4b899ac8 spi_read 181 c444216a6ba2a4a66cccd60a0dd062bce4b865dd52b200ef5e21838c4b899ac8 spi_test 182 183 If the flash comes erased by default and the previous erase was ignored, 184 we won't catch it, thus test the erase again:: 185 186 root@1:~# mtd_debug erase /dev/mtd0 0 2097152 187 Erased 2097152 bytes from address 0x00000000 in flash 188 189 root@1:~# mtd_debug read /dev/mtd0 0 2097152 spi_read 190 Copied 2097152 bytes from address 0x00000000 in flash to spi_read 191 192 root@1:~# sha256sum spi* 193 4bda3a28f4ffe603c0ec1258c0034d65a1a0d35ab7bd523a834608adabf03cc5 spi_read 194 c444216a6ba2a4a66cccd60a0dd062bce4b865dd52b200ef5e21838c4b899ac8 spi_test 195 196 Dump some other relevant data:: 197 198 root@1:~# mtd_debug info /dev/mtd0 199 mtd.type = MTD_NORFLASH 200 mtd.flags = MTD_CAP_NORFLASH 201 mtd.size = 8388608 (8M) 202 mtd.erasesize = 4096 (4K) 203 mtd.writesize = 1 204 mtd.oobsize = 0 205 regions = 0
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