Re: Read CPDL firmware version on Edgecore AS5114-48X

[Jean Delvare <jdelvare@suse.de>]

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