Re: [PATCH 2/3] dts: mpc512x: adjust clock specs for FEC nodes

2014-03-06 Thread Sascha Hauer
On Wed, Mar 05, 2014 at 11:52:09AM +0100, Gerhard Sittig wrote:
 On Wed, Mar 05, 2014 at 09:48 +0800, Shawn Guo wrote:
  
  On Mon, Mar 03, 2014 at 10:22:31AM +0100, Gerhard Sittig wrote:
   On Mon, Feb 24, 2014 at 11:25 +0100, Gerhard Sittig wrote:

a recent FEC binding document update that was motivated by i.MX
development revealed that ARM and PowerPC implementations in Linux
did not agree on the clock names to use for the FEC nodes

change clock names from per to ipg in the FEC nodes of the
mpc5121.dtsi include file such that the .dts specs comply with
the common FEC binding

this incompatible change does not break operation, because
- COMMON_CLK support for MPC5121/23/25 and adjusted .dts files
  were only introduced in Linux v3.14-rc1, no mainline release
  provided these specs before
- if this change won't make it for v3.14, the MPC512x CCF support
  provides full backwards compability, and keeps operating with
  device trees which lack clock specs or don't match in the names

Signed-off-by: Gerhard Sittig g...@denx.de
   
   ping
   
   Are there opinions about making PowerPC users of FEC use the same
   clock names as ARM users do, to re-use (actually: keep sharing)
   the FEC binding?  The alternative would be to fragment the FEC
   binding into several bindings for ARM and PowerPC, which I feel
   would be undesirable, and is not necessary.
  
  As I already said, Documentation/devicetree/bindings/net/fsl-fec.txt
  was created specifically for i.MX FEC controller from day one.  And even
  as of today, it doesn't serve PowerPC, because for example the property
  'phy-mode' documented as required one is not required by PowerPC FEC.
  My opinion would be to patch fsl-fec.txt a little bit to make it clear
  that it's a binding doc for i.MX FEC, and create the other one for
  PowerPC FEC.  This is the way less confusing to people and easier for
  binding maintenance.
 
 Should we still try to have a common behaviour where possible?
 Such that even if there are two bindings, they don't diverge in
 unnecessary ways?

Maybe the long term goal should be to share the code. The MPC5200 FEC
and the i.MX FEC are very similar. Only the DMA engine is quite
different.

Sascha

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Re: [PATCH 2/3] dts: mpc512x: adjust clock specs for FEC nodes

2014-03-05 Thread Gerhard Sittig
On Wed, Mar 05, 2014 at 09:48 +0800, Shawn Guo wrote:
 
 On Mon, Mar 03, 2014 at 10:22:31AM +0100, Gerhard Sittig wrote:
  On Mon, Feb 24, 2014 at 11:25 +0100, Gerhard Sittig wrote:
   
   a recent FEC binding document update that was motivated by i.MX
   development revealed that ARM and PowerPC implementations in Linux
   did not agree on the clock names to use for the FEC nodes
   
   change clock names from per to ipg in the FEC nodes of the
   mpc5121.dtsi include file such that the .dts specs comply with
   the common FEC binding
   
   this incompatible change does not break operation, because
   - COMMON_CLK support for MPC5121/23/25 and adjusted .dts files
 were only introduced in Linux v3.14-rc1, no mainline release
 provided these specs before
   - if this change won't make it for v3.14, the MPC512x CCF support
 provides full backwards compability, and keeps operating with
 device trees which lack clock specs or don't match in the names
   
   Signed-off-by: Gerhard Sittig g...@denx.de
  
  ping
  
  Are there opinions about making PowerPC users of FEC use the same
  clock names as ARM users do, to re-use (actually: keep sharing)
  the FEC binding?  The alternative would be to fragment the FEC
  binding into several bindings for ARM and PowerPC, which I feel
  would be undesirable, and is not necessary.
 
 As I already said, Documentation/devicetree/bindings/net/fsl-fec.txt
 was created specifically for i.MX FEC controller from day one.  And even
 as of today, it doesn't serve PowerPC, because for example the property
 'phy-mode' documented as required one is not required by PowerPC FEC.
 My opinion would be to patch fsl-fec.txt a little bit to make it clear
 that it's a binding doc for i.MX FEC, and create the other one for
 PowerPC FEC.  This is the way less confusing to people and easier for
 binding maintenance.

Should we still try to have a common behaviour where possible?
Such that even if there are two bindings, they don't diverge in
unnecessary ways?

But given that we already are past -rc5, I guess the suggested
change is too late for v3.14 anyway.  So we have to live with the
fact of a mainline release of different behaviour.

And the backwards compatibility support in the MPC512x CCF
implementation allows to cope with a potential future ipg
unification while still working with former per using device
trees.  There's no blocker.  So nevermind.


virtually yours
Gerhard Sittig
-- 
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HRB 165235 Munich, Office: Kirchenstr. 5, D-82194 Groebenzell, Germany
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Re: [PATCH 2/3] dts: mpc512x: adjust clock specs for FEC nodes

2014-03-04 Thread Shawn Guo
On Mon, Mar 03, 2014 at 10:22:31AM +0100, Gerhard Sittig wrote:
 On Mon, Feb 24, 2014 at 11:25 +0100, Gerhard Sittig wrote:
  
  a recent FEC binding document update that was motivated by i.MX
  development revealed that ARM and PowerPC implementations in Linux
  did not agree on the clock names to use for the FEC nodes
  
  change clock names from per to ipg in the FEC nodes of the
  mpc5121.dtsi include file such that the .dts specs comply with
  the common FEC binding
  
  this incompatible change does not break operation, because
  - COMMON_CLK support for MPC5121/23/25 and adjusted .dts files
were only introduced in Linux v3.14-rc1, no mainline release
provided these specs before
  - if this change won't make it for v3.14, the MPC512x CCF support
provides full backwards compability, and keeps operating with
device trees which lack clock specs or don't match in the names
  
  Signed-off-by: Gerhard Sittig g...@denx.de
 
 ping
 
 Are there opinions about making PowerPC users of FEC use the same
 clock names as ARM users do, to re-use (actually: keep sharing)
 the FEC binding?  The alternative would be to fragment the FEC
 binding into several bindings for ARM and PowerPC, which I feel
 would be undesirable, and is not necessary.

As I already said, Documentation/devicetree/bindings/net/fsl-fec.txt
was created specifically for i.MX FEC controller from day one.  And even
as of today, it doesn't serve PowerPC, because for example the property
'phy-mode' documented as required one is not required by PowerPC FEC.
My opinion would be to patch fsl-fec.txt a little bit to make it clear
that it's a binding doc for i.MX FEC, and create the other one for
PowerPC FEC.  This is the way less confusing to people and easier for
binding maintenance.

Shawn

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Re: [PATCH 2/3] dts: mpc512x: adjust clock specs for FEC nodes

2014-03-03 Thread Gerhard Sittig
On Mon, Feb 24, 2014 at 11:25 +0100, Gerhard Sittig wrote:
 
 a recent FEC binding document update that was motivated by i.MX
 development revealed that ARM and PowerPC implementations in Linux
 did not agree on the clock names to use for the FEC nodes
 
 change clock names from per to ipg in the FEC nodes of the
 mpc5121.dtsi include file such that the .dts specs comply with
 the common FEC binding
 
 this incompatible change does not break operation, because
 - COMMON_CLK support for MPC5121/23/25 and adjusted .dts files
   were only introduced in Linux v3.14-rc1, no mainline release
   provided these specs before
 - if this change won't make it for v3.14, the MPC512x CCF support
   provides full backwards compability, and keeps operating with
   device trees which lack clock specs or don't match in the names
 
 Signed-off-by: Gerhard Sittig g...@denx.de

ping

Are there opinions about making PowerPC users of FEC use the same
clock names as ARM users do, to re-use (actually: keep sharing)
the FEC binding?  The alternative would be to fragment the FEC
binding into several bindings for ARM and PowerPC, which I feel
would be undesirable, and is not necessary.

It would be nice to ship v3.14 (the first release with proper CCF
support for MPC512x) in a shape that is consistent with other FEC
users (ARM i.MX).  We are lucky to have noticed the difference
before the release, and need not introduce the incompatibility,
and need not document and support obsolete conditions but can fix
them instead.

 ---
  arch/powerpc/boot/dts/mpc5121.dtsi |4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)
 
 diff --git a/arch/powerpc/boot/dts/mpc5121.dtsi 
 b/arch/powerpc/boot/dts/mpc5121.dtsi
 index 2c0e1552d20b..a5a375598ed8 100644
 --- a/arch/powerpc/boot/dts/mpc5121.dtsi
 +++ b/arch/powerpc/boot/dts/mpc5121.dtsi
 @@ -281,7 +281,7 @@
   #address-cells = 1;
   #size-cells = 0;
   clocks = clks MPC512x_CLK_FEC;
 - clock-names = per;
 + clock-names = ipg;
   };
  
   eth0: ethernet@2800 {
 @@ -291,7 +291,7 @@
   local-mac-address = [ 00 00 00 00 00 00 ];
   interrupts = 4 0x8;
   clocks = clks MPC512x_CLK_FEC;
 - clock-names = per;
 + clock-names = ipg;
   };
  
   /* USB1 using external ULPI PHY */
 -- 
 1.7.10.4


virtually yours
Gerhard Sittig
-- 
DENX Software Engineering GmbH, MD: Wolfgang Denk  Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr. 5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: off...@denx.de
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