Subject: Re: [PATCH net-next 01/10] net: netcp: ethss: add support of subsystem register region regmap

From: Murali Karicheri <[email-masked]>
Date: Thu, 5 Jan 2017 17:08:54 -0500

On 01/05/2017 03:42 PM, Murali Karicheri wrote:
> Rob,
> 
> On 12/22/2016 04:24 PM, Rob Herring wrote:
>> On Tue, Dec 20, 2016 at 05:09:44PM -0500, Murali Karicheri wrote:
>>> From: WingMan Kwok <[email-masked]>
>>>
>>> 10gbe phy driver needs to access the 10gbe subsystem control
>>> register during phy initialization. To facilitate the shared
>>> access of the subsystem register region between the 10gbe Ethernet
>>> driver and the phy driver, this patch adds support of the
>>> subsystem register region defined by a syscon node in the dts.
>>>
>>> Although there is no shared access to the gbe subsystem register
>>> region, using syscon for that is for the sake of consistency.
>>>
>>> This change is backward compatible with previously released gbe
>>> devicetree bindings.
>>>
>>> Signed-off-by: WingMan Kwok <[email-masked]>
>>> Signed-off-by: Murali Karicheri <[email-masked]>
>>> Signed-off-by: Sekhar Nori <[email-masked]>
>>> ---
>>>  .../devicetree/bindings/net/keystone-netcp.txt     |  16 ++-
>>>  drivers/net/ethernet/ti/netcp_ethss.c              | 140 +++++++++++++++++----
>>>  2 files changed, 127 insertions(+), 29 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/net/keystone-netcp.txt b/Documentation/devicetree/bindings/net/keystone-netcp.txt
>>> index 04ba1dc..0854a73 100644
>>> --- a/Documentation/devicetree/bindings/net/keystone-netcp.txt
>>> +++ b/Documentation/devicetree/bindings/net/keystone-netcp.txt
>>> @@ -72,20 +72,24 @@ Required properties:
>>>  		"ti,netcp-gbe-2" for 1GbE N NetCP 1.5 (N=2)
>>>  		"ti,netcp-xgbe" for 10 GbE
>>>  
>>> +- syscon-subsys:	phandle to syscon node of the switch
>>> +			subsystem registers.
>>> +
>>>  - reg:		register location and the size for the following register
>>>  		regions in the specified order.
>>>  		- switch subsystem registers
>>> +		- sgmii module registers
>>
>> This needs to go on the end of the list. Otherwise, it is not backwards 
>> compatible.
> 
> Thanks for your review! I assumed backward compatibility means new kernel
> should work with old DTB. The driver code is adjusted to work with both
> DTBs. Isn't that enough?
Rob,

I will pull out 1/10 and 2/10 from the series as it needs more work and
re-submit rest of the patches in my v1 spin. However please reply to my
above backward compatibility question.

Thanks and Regards,

Murali
> 
> Murali
> 
>>
>>>  		- sgmii port3/4 module registers (only for NetCP 1.4)
>>>  		- switch module registers
>>>  		- serdes registers (only for 10G)
>>>  
>>>  		NetCP 1.4 ethss, here is the order
>>> -			index #0 - switch subsystem registers
>>> +			index #0 - sgmii module registers
>>>  			index #1 - sgmii port3/4 module registers
>>>  			index #2 - switch module registers
>>>  
>>>  		NetCP 1.5 ethss 9 port, 5 port and 2 port
>>> -			index #0 - switch subsystem registers
>>> +			index #0 - sgmii module registers
>>>  			index #1 - switch module registers
>>>  			index #2 - serdes registers
>>>  
>>> @@ -145,6 +149,11 @@ Optional properties:
>>>  
>>>  Example binding:
>>>  
>>> +gbe_subsys: subsys@2090000 {
>>> +	compatible = "syscon";
>>> +	reg = <0x02090000 0x100>;
>>> +};
>>> +
>>>  netcp: netcp@2000000 {
>>>  	reg = <0x2620110 0x8>;
>>>  	reg-names = "efuse";
>>> @@ -163,7 +172,8 @@ netcp: netcp@2000000 {
>>>  		ranges;
>>>  		gbe@90000 {
>>>  			label = "netcp-gbe";
>>> -			reg = <0x90000 0x300>, <0x90400 0x400>, <0x90800 0x700>;
>>> +			syscon-subsys = <&gbe_subsys>;
>>> +			reg = <0x90100 0x200>, <0x90400 0x200>, <0x90800 0x700>;
>>>  			/* enable-ale; */
>>>  			tx-queue = <648>;
>>>  			tx-channel = <8>;
>>
> 
> 

-- 
Murali Karicheri
Linux Kernel, Keystone