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

[Wang, Haiyue]

Thanks Avi, wait for your response when new patch is ready. :-)

BR,
Haiyue


On 2018-01-17 20:54, Avi Fishman wrote:
> 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
>>