Re: [PATCH v2 2/2] powerpc/mpic: add global timer support

[Scott Wood <scottwood@freescale.com>]

On 08/13/2012 09:00 PM, Wang Dongsheng-B40534 wrote:
> 
> 
>> -----Original Message-----
>> From: Wood Scott-B07421
>> Sent: Tuesday, August 14, 2012 1:37 AM
>> To: Wang Dongsheng-B40534
>> Cc: Wood Scott-B07421; benh@kernel.crashing.org; paulus@samba.org;
>> linuxppc-dev@lists.ozlabs.org; Gala Kumar-B11780; Li Yang-R58472
>> Subject: Re: [PATCH v2 2/2] powerpc/mpic: add global timer support
>>
>> On 08/13/2012 01:18 AM, Wang Dongsheng-B40534 wrote:
>>>>> +	p = of_get_property(np, "available-ranges", &len);
>>>>> +	if (p && len % (2 * sizeof(u32)) != 0) {
>>>>> +		pr_err("%s: malformed fsl,available-ranges property.\n",
>>>>> +				np->full_name);
>>>>> +		return -EINVAL;
>>>>> +	}
>>>>
>>>> You need to support fsl,available-ranges since that's in an accepted
>>>> binding and people could have partitioned setups already using it.
>>>>
>>> [Wang Dongsheng] FSL chip or OPEN-PIC specification(Only a group) in
>>> each group only four timer. This is unified. So i use a generic name.
>>> I think there is not compatible with existing mpic timer nodes.
>>
>> We need to be compatible with existing trees, so you'd need to check for
>> both -- but I think any further discussion of the details is premature
>> until we decide whether this is worthwhile to begin with (both the
>> support of non-FSL timers, and the creation of a new device tree binding
>> which will not be implemented by many of the machines that have non-FSL
>> openpic because they run real Open Firmware).
>>
> [Wang Dongsheng] 
> 	p = of_get_property(np, "available-ranges", &len);
> 	if (!p)
> 		p = of_get_property(np, "fsl,available-ranges", &len);
> 	
> 	this code be compatible with existing trees.

Yes, that's what I meant by checking both.

I still think we need to discuss why we're doing this first.  What
specific machines are going to have these new openpic timer nodes?

-Scott