[PATCH arm/aspeed/ast2500 v1] ipmi: add an Aspeed KCS IPMI BMC driver

[Avi Fishman]

Sounds great for us (Nuvoton).

Avi.

On Wed, Jan 17, 2018 at 8:32 AM, Wang, Haiyue
<haiyue.wang at linux.intel.com> wrote:
>
>
> On 2018-01-17 07:06, Joel Stanley wrote:
>>
>> On Tue, Jan 16, 2018 at 2:59 PM, Corey Minyard <minyard at acm.org> wrote:
>>>
>>> On 01/16/2018 05:43 AM, Haiyue Wang wrote:
>>>>
>>>> The KCS (Keyboard Controller Style) interface is used to perform in-band
>>>> IPMI communication between a server host and its BMC (BaseBoard
>>>> Management
>>>> Controllers).
>>>>
>>>> This driver exposes the KCS interface on ASpeed SOCs (AST2400 and
>>>> AST2500)
>>>> as a character device. Such SOCs are commonly used as BMCs and this
>>>> driver
>>>> implements the BMC side of the KCS interface.
>>>
>>>
>>> I thought we were going to unify the BMC ioctl interface?  My preference
>>> would be to
>>> create a file named include/uapi/linux/ipmi-bmc.h and add the following:
>>>
>>> #define __IPMI_BMC_IOCTL_MAGIC    0xb1
>>> #define IPMI_BMC_IOCTL_SMS_SET_ATN    _IO(__IPMI_BMC_IOCTL_MAGIC, 0x00)
>>>
>>> to make it the same as BT.  Then in bt-bmc.h, set BT_BMC_IOCTL_SMS_ATN to
>>> IPMI_BMC_IOCTL_SMS_SET_ATN.  Then add the KCS ioctls in ipmi-bmc.h and
>>> use that.  That way we stay backward compatible but we are unified.
>>>
>>> Since more KCS interfaces may come around, can you make the name more
>>> specific?  (I made this same error on bt-bmc,c, it should probably be
>>> renamed.)
>>
>> Yes, we had a group of openbmc people get together recently and spoke
>> about this. Unfortunately Haiyue wasn't there (but other Intel BMC
>> people were).
>>
>> We've got code coming from another BMC vendor who will use the same
>> userspace API. The intention is to unify ASPEED's KCS and BT, along
>> with Nuvoton's KCS and BT, as you outlined above.
>
> Great design for common BMC code, thanks Joel & Corey.
>
> Then we need to divide the kcs-bmc.c into two files, one (still kcs-bmc.c)
> is for handling IPMI KCS state
> according to IPMI 2.0 specification, and also handing device misc
> operations; another file is called such
> as aspeed-kcs-bmc.c which handles ast2500 kcs controller. So that Nuvoton
> can define nvvoton-kcs-bmc.c
> low level API, and call the IPMI KCS function in kcs-bmc.c ?
>
> How about this idea ? If it makes sense, I will change the code for review
> in patch v2.
>
>> Cheers,
>>
>> Joel
>
>