Hi Paul, On Wed, 21 Jun 2023 09:59:44 +0200, Paul Menzel wrote: > I am trying to read the CPDL firmware version of the switch Edgecore > AS5114-48X with dentOS (Debian based). > > In U-Boot it supposedly work like below: > > Marvell>> i2c dev 2 > Marvell>> i2c md 0x40 01 1 > 0001: 01 > Marvell>> i2c md 0x40 ff 1 > 00ff: 03 > > But I like to do it with GNU/Linux, but my attempts failed: > > ``` > # i2cdetect -y 2 > 0 1 2 3 4 5 6 7 8 9 a b c d e f > 00: -- -- -- -- -- -- -- -- -- -- -- -- -- > 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 50: UU UU -- -- -- -- -- -- -- -- -- -- -- -- -- -- > 60: -- -- -- -- -- -- -- -- -- -- 6a -- -- -- -- -- > 70: -- UU UU UU UU UU UU -- > ``` > > Nothing seems to be at address 0x40: > > ``` > # i2cdump -f -y 2 0x40 > No size specified (using byte-data access) > 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef > 00: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > (...) > f0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX > ``` > > Could the bus be different? Yes, unlike the PCI bus which has a well defined topology, multiple I2C root segments can coexist in a system and their numbering is largely arbitrary. So there's no guarantee that i2c bus 2 on U-Boot is the same as i2c bus 2 on Linux. I'm not familiar with U-Boot but you may try "i2c dev" or "i2c bus" commands there, maybe it will tell you what corresponds to i2c bus 2. > (...) > # find / -iname *cpld* > /sys/bus/i2c/drivers/as4224_cpld > (...) > # ls -l /sys/bus/i2c/drivers/as4224_cpld/ > total 0 > lrwxrwxrwx 1 root root 0 Jun 20 16:53 0-0040 -> > ../../../../devices/platform/ap806/ap806:config-space@f0000000/f0511000.i2c/i2c-0/0-0040 > --w------- 1 root root 4096 Jun 20 16:53 bind > lrwxrwxrwx 1 root root 0 Jun 20 16:53 module -> > ../../../../module/arm64_accton_as4224_cpld > --w------- 1 root root 4096 May 16 10:21 uevent > --w------- 1 root root 4096 Jun 20 16:53 unbind > ``` > > Is it bus 0? Seems so, yes. > > ``` > # i2cdump -f -y 0 0x40 > No size specified (using byte-data access) > 0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef > 00: 80 01 ff 07 0f cc cc cc cc cc cc cc cc cc cc cc ??.????????????? > 10: ff 03 3f cc 01 cc cc cc cc cc cc cc cc cc cc cc .??????????????? > 20: ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc .??????????????? > 30: ff ff ff ff cc cc cc cc cc cc cc cc cc cc cc cc ....???????????? > 40: cc cc cc 0e cc cc cc cc cc cc cc cc cc cc cc cc ???????????????? > 50: 0d 4a 03 00 7f cc cc cc cc cc cc cc cc cc cc cc ?J?.???????????? > 60: 01 71 1e cc cc cc cc cc cc cc cc cc cc cc cc cc ?q?????????????? > 70: 7f 7f 7f 7f 7f cc cc cc cc cc cc cc cc cc cc cc ???????????????? > 80: 6c 69 69 69 68 cc cc cc cc cc cc cc cc cc cc cc liiih??????????? > 90: 02 00 71 71 cc cc cc cc cc cc cc cc cc cc cc cc ?.qq???????????? > a0: ff ff ff ff ff ff ff ff ff ff ff 7f cc cc cc cc ...........????? > b0: ff ff ff ff ff ff 00 00 00 00 00 00 cc cc cc cc ............???? > c0: 0f fe ff ff ff 3f 00 00 00 00 00 00 cc cc cc cc ??...?......???? > d0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ???????????????? > e0: 00 71 cc cc cc cc cc cc cc cc cc cc cc cc cc cc .q?????????????? > f0: 41 53 35 31 31 34 00 00 00 00 00 00 41 57 53 05 AS5114......AWS? > ``` > > What would be the values of `0x40 01 1` and ` 0x40 ff 1`? As I understand the U-Boot i2c command syntax, 0x40 is the slave address, 01/ff is the register offset (in hexadecimal, despite no leading "0x") and 1 is the register count. So the equivalent Linux i2c-tools commands, assuming i2c bus 0, would be: # i2cget 0 0x40 0x01 b # i2cget 0 0x40 0xff b >From the full register dump above, these commands will most probably return values (0x)01 and (0x)05, respectively. The former matches what you got from U-Boot, the latter doesn't. Which may or may not indicate a problem, depending on whether these values are supposed to be static or if they could change over time. Hope that helps, -- Jean Delvare SUSE L3 Support
