Re: [PATCH 4/5] doc: ABI: bone_capemgr sysfs API

From: Pantelis Antoniou
Date: Wed May 13 2015 - 07:57:08 EST


Hi Greg,

> On May 13, 2015, at 14:52 , Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, May 13, 2015 at 10:59:44AM +0300, Pantelis Antoniou wrote:
>> Document the beaglebone's capemgr sysfs API
>>
>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
>> ---
>> .../testing/sysfs-devices-platform-bone_capemgr | 63 ++++++++++++++++++++++
>> 1 file changed, 63 insertions(+)
>> create mode 100644 Documentation/ABI/testing/sysfs-devices-platform-bone_capemgr
>>
>> diff --git a/Documentation/ABI/testing/sysfs-devices-platform-bone_capemgr b/Documentation/ABI/testing/sysfs-devices-platform-bone_capemgr
>> new file mode 100644
>> index 0000000..e2df613
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/sysfs-devices-platform-bone_capemgr
>> @@ -0,0 +1,63 @@
>> +What: /sys/devices/platform/bone_capemgr/slots
>> +Date: May 2015
>> +KernelVersion: 4.0
>
> I don't think that version is correct :)
>

Bah, ++

>> +Contact: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
>> +Description:
>> + READ:
>> + Describe the state of all the slots of the beaglebone capemgr.
>> + Each line of the output describes a slot:
>
> sysfs files are "one value per file", so a sysfs file that displays
> multiple lines like this is not allowed at all, sorry.
>
> Please either make it a debugfs file (if this is only for debugging, or
> split it out into individual files, one per slot (hint, one per slot is
> probably best.)
>

Well, itâs a status file. And itâs been used as is for a couple of years
so it was worth a shot for backward compatibility.


>> + The slot format is as following:
>> + <slot-id>: [P-][F-][O-][l-][L-][D-] \
>> + <overlay-id> <board-name>,<version>,
>> + <manufacturer>,<part-number>
>> +
>> + Where the flags are:
>> + P: Slot has been probed
>> + F: Slot has failed probing (i.e. no EEPROM detected)
>> + O: Slot has been overridden by the user
>> + l: Slot is current loading
>> + L: Slot has completed loading and is ready
>> + D: Slot has been disabled
>> +
>> + Example:
>> + 0: P---L- -1 BeagleBone RS232 CAPE,00A1,Beagleboardtoys,BB-BONE-SERL-03
>> + 1: PF---- -1
>> + 2: PF---- -1
>> + 3: PF---- -1
>> +
>> + WRITE:
>> + Writing a string of the form <part-number>[:version] issues a request to
>> + load a firmware blob containing an overlay. The name of the firmware blob
>> + is <part-number>-[version|00A0].dtbo. This act is defined as a slot override.
>> +
>> + Writing a negative slot id removes the slot if it was an overridden one, or
>> + unloads a slot that was probed.
>> +
>> +What: /sys/devices/platform/bone_capemgr/baseboard/<eeprom-field>
>> +Date: May 2015
>> +KernelVersion: 4.0
>> +Contact: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
>> +Description: Contains the probed base board EEPROM field; one of:
>> + board-name - board-name as stored in cape EEPROM
>> + dc-supplied - whether the cape draws or supplies DC
>> + eeprom-format-revision - EEPROM format rev, only 00A0 supported
>> + header - header; should be 'aa 55 33 ee'
>
> If it's always this value, why have the file?
>

These are the contents of the EEPROM. If the format of the EEPROM changes then the
header information will change.

>> + manufacturer - manufacturer string
>> + part-number - part-number of the cape
>> + serial-number - serial number of the cape
>> + version - version of the cape, i.e. 00A0
>> + number-of-pins - displayed but ignored
>> + pin-usage - displayed but ignored
>> + sys-5v - displayed but ignored
>> + vdd-3v3exp - displayed but ignored
>> + vdd-5v - displayed but ignored
>
> Are these all individual different files?
>

Yes

>> +What: /sys/devices/platform/bone_capemgr/slot-<n>/<eeprom-field>
>
> No blank line?
>

OK

>> +Date: May 2015
>> +KernelVersion: 4.0
>> +Contact: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
>> +Description: Contains the probed cape's EEPROM field; the field is one of:
>> + board-name - baseboard name i.e. A335BNLT
>> + header - header; should be 'aa 55 33 ee'
>> + revision - baseboard revision
>> + serial-number - baseboard serial number
>> + config-option - displayed but ignored
>
> Same here, are these all individual files?
>

Yes.

> thanks,
>
> greg k-h

Regards

â Pantelis

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