[PATCH][POWERPC] QE: Make QUICC Engine support a configurable option

[PATCH][POWERPC] QE: Make QUICC Engine support a configurable option

[Kumar Gala]

Allow us choose if we want QE support or not.  This is similiar to what
we do for the CPM2.  Its feasible to use a processor that has QE HW and not
use any of the QE functionality.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

---
commit a554f9b39496127face86d3afc6eb4a9aebef65b
tree f144b3290bc2cc04aa27591f4003f9b9249216f6
parent bfbb5a94dd58d2492d34338419a912440b660132
author Kumar Gala <galak@kernel.crashing.org> Wed, 14 Mar 2007 13:14:02 -0500
committer Kumar Gala <galak@kernel.crashing.org> Wed, 14 Mar 2007 13:14:02 -0500

 arch/powerpc/Kconfig                |    8 --------
 arch/powerpc/platforms/83xx/Kconfig |   12 ++++++++++--
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 5e1ac10..927f512 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -394,14 +394,6 @@ config APUS
 	  <http://linux-apus.sourceforge.net/>.
 endchoice

-config QUICC_ENGINE
-	bool
-	help
-	  The QUICC Engine (QE) is a new generation of communications
-	  coprocessors on Freescale embedded CPUs (akin to CPM in older chips).
-	  Selecting this option means that you wish to build a kernel
-	  for a machine with a QE coprocessor.
-
 config PPC_PSERIES
 	depends on PPC_MULTIPLATFORM && PPC64
 	bool "IBM pSeries & new (POWER5-based) iSeries"
diff --git a/arch/powerpc/platforms/83xx/Kconfig b/arch/powerpc/platforms/83xx/Kconfig
index 713b31a..745378d 100644
--- a/arch/powerpc/platforms/83xx/Kconfig
+++ b/arch/powerpc/platforms/83xx/Kconfig
@@ -14,7 +14,6 @@ config MPC8313_RDB
 config MPC832x_MDS
 	bool "Freescale MPC832x MDS"
 	select DEFAULT_UIMAGE
-	select QUICC_ENGINE
 	help
 	  This option enables support for the MPC832x MDS evaluation board.

@@ -41,12 +40,21 @@ config MPC834x_ITX
 config MPC836x_MDS
 	bool "Freescale MPC836x MDS"
 	select DEFAULT_UIMAGE
-	select QUICC_ENGINE
 	help
 	  This option enables support for the MPC836x MDS Processor Board.

 endchoice

+config QUICC_ENGINE
+	bool "QUICC Engine Support"
+	depends on PPC_MPC836x || PPC_MPC832x
+	default y
+	---help---
+	  The QUICC Engine (QE) is a new generation of communications
+	  coprocessors on Freescale embedded CPUs (akin to CPM in older chips).
+	  Selecting this option means that you wish to build a kernel
+	  for a machine with a QE coprocessor.
+
 config PPC_MPC831x
 	bool
 	select PPC_UDBG_16550

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurable option

[Kim Phillips]

On Wed, 14 Mar 2007 13:15:05 -0500 (CDT)
Kumar Gala <galak@kernel.crashing.org> wrote:

> 
>  arch/powerpc/Kconfig                |    8 --------
>  arch/powerpc/platforms/83xx/Kconfig |   12 ++++++++++--
>  2 files changed, 10 insertions(+), 10 deletions(-)

What about 85xx QE support?

Kim

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurable option

[Timur Tabi]

Kim Phillips wrote:
> On Wed, 14 Mar 2007 13:15:05 -0500 (CDT)
> Kumar Gala <galak@kernel.crashing.org> wrote:
> 
>>  arch/powerpc/Kconfig                |    8 --------
>>  arch/powerpc/platforms/83xx/Kconfig |   12 ++++++++++--
>>  2 files changed, 10 insertions(+), 10 deletions(-)
> 
> What about 85xx QE support?

Kumar and I talked about it.  85xx support will be added when QE works on 85xx.  However, 
the patch still needs changes.  To allow each CPU family to have its own QE option, we'll 
need to define something like QUICC_ENGINE_83xx and QUICC_ENGINE_85xx, and then have 
something like this:

config QUICC_ENGINE
	bool
	default y if QUICC_ENGINE_83xx || QUICC_ENGINE_85xx

-- 
Timur Tabi
Linux Kernel Developer @ Freescale

RE: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Li Yang-r58472]

> -----Original Message-----
> From: linuxppc-dev-bounces+leoli=3Dfreescale.com@ozlabs.org
> [mailto:linuxppc-dev-bounces+leoli=3Dfreescale.com@ozlabs.org] On =
Behalf
Of Timur
> Tabi
> Sent: Thursday, March 15, 2007 3:36 AM
> To: Phillips Kim-R1AAHA
> Cc: linuxppc-dev@ozlabs.org
> Subject: Re: [PATCH][POWERPC] QE: Make QUICC Engine support a
configurableoption
>=20
> Kim Phillips wrote:
> > On Wed, 14 Mar 2007 13:15:05 -0500 (CDT)
> > Kumar Gala <galak@kernel.crashing.org> wrote:
> >
> >>  arch/powerpc/Kconfig                |    8 --------
> >>  arch/powerpc/platforms/83xx/Kconfig |   12 ++++++++++--
> >>  2 files changed, 10 insertions(+), 10 deletions(-)
> >
> > What about 85xx QE support?
>=20
> Kumar and I talked about it.  85xx support will be added when QE works
on 85xx.
> However,
> the patch still needs changes.  To allow each CPU family to have its
own QE option,
> we'll
> need to define something like QUICC_ENGINE_83xx and QUICC_ENGINE_85xx,
and then
> have
> something like this:
>=20
> config QUICC_ENGINE
> 	bool
> 	default y if QUICC_ENGINE_83xx || QUICC_ENGINE_85xx

I don't think we need these new options.  If there are differences
between the two SOC versions, presumably not too many, we can address
them in device tree.  It's better to leave the QUICC_ENGINE option at
arch/powerpc/Kconfig level, IMHO.

- Leo

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Kumar Gala]

On Mar 14, 2007, at 10:02 PM, Li Yang-r58472 wrote:

>> -----Original Message-----
>> From: linuxppc-dev-bounces+leoli=freescale.com@ozlabs.org
>> [mailto:linuxppc-dev-bounces+leoli=freescale.com@ozlabs.org] On  
>> Behalf
> Of Timur
>> Tabi
>> Sent: Thursday, March 15, 2007 3:36 AM
>> To: Phillips Kim-R1AAHA
>> Cc: linuxppc-dev@ozlabs.org
>> Subject: Re: [PATCH][POWERPC] QE: Make QUICC Engine support a
> configurableoption
>>
>> Kim Phillips wrote:
>>> On Wed, 14 Mar 2007 13:15:05 -0500 (CDT)
>>> Kumar Gala <galak@kernel.crashing.org> wrote:
>>>
>>>>  arch/powerpc/Kconfig                |    8 --------
>>>>  arch/powerpc/platforms/83xx/Kconfig |   12 ++++++++++--
>>>>  2 files changed, 10 insertions(+), 10 deletions(-)
>>>
>>> What about 85xx QE support?
>>
>> Kumar and I talked about it.  85xx support will be added when QE  
>> works
> on 85xx.
>> However,
>> the patch still needs changes.  To allow each CPU family to have its
> own QE option,
>> we'll
>> need to define something like QUICC_ENGINE_83xx and  
>> QUICC_ENGINE_85xx,
> and then
>> have
>> something like this:
>>
>> config QUICC_ENGINE
>> 	bool
>> 	default y if QUICC_ENGINE_83xx || QUICC_ENGINE_85xx
>
> I don't think we need these new options.  If there are differences
> between the two SOC versions, presumably not too many, we can address
> them in device tree.  It's better to leave the QUICC_ENGINE option at
> arch/powerpc/Kconfig level, IMHO.


The issue isn't dealing with differences between 83xx/85xx.  Its  
allowing the choice for only those two subarchs.

- k

RE: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Li Yang-r58472]

> -----Original Message-----
> From: Kumar Gala [mailto:galak@kernel.crashing.org]
> Sent: Thursday, March 15, 2007 11:49 AM
> To: Li Yang-r58472
> Cc: Tabi Timur-B04825; Phillips Kim-R1AAHA; linuxppc-dev@ozlabs.org
> Subject: Re: [PATCH][POWERPC] QE: Make QUICC Engine support a
configurableoption
>=20
>=20
> On Mar 14, 2007, at 10:02 PM, Li Yang-r58472 wrote:
>=20
> >> -----Original Message-----
> >> From: linuxppc-dev-bounces+leoli=3Dfreescale.com@ozlabs.org
> >> [mailto:linuxppc-dev-bounces+leoli=3Dfreescale.com@ozlabs.org] On
> >> Behalf
> > Of Timur
> >> Tabi
> >> Sent: Thursday, March 15, 2007 3:36 AM
> >> To: Phillips Kim-R1AAHA
> >> Cc: linuxppc-dev@ozlabs.org
> >> Subject: Re: [PATCH][POWERPC] QE: Make QUICC Engine support a
> > configurableoption
> >>
> >> Kim Phillips wrote:
> >>> On Wed, 14 Mar 2007 13:15:05 -0500 (CDT)
> >>> Kumar Gala <galak@kernel.crashing.org> wrote:
> >>>
> >>>>  arch/powerpc/Kconfig                |    8 --------
> >>>>  arch/powerpc/platforms/83xx/Kconfig |   12 ++++++++++--
> >>>>  2 files changed, 10 insertions(+), 10 deletions(-)
> >>>
> >>> What about 85xx QE support?
> >>
> >> Kumar and I talked about it.  85xx support will be added when QE
> >> works
> > on 85xx.
> >> However,
> >> the patch still needs changes.  To allow each CPU family to have
its
> > own QE option,
> >> we'll
> >> need to define something like QUICC_ENGINE_83xx and
> >> QUICC_ENGINE_85xx,
> > and then
> >> have
> >> something like this:
> >>
> >> config QUICC_ENGINE
> >> 	bool
> >> 	default y if QUICC_ENGINE_83xx || QUICC_ENGINE_85xx
> >
> > I don't think we need these new options.  If there are differences
> > between the two SOC versions, presumably not too many, we can
address
> > them in device tree.  It's better to leave the QUICC_ENGINE option
at
> > arch/powerpc/Kconfig level, IMHO.
>=20
>=20
> The issue isn't dealing with differences between 83xx/85xx.  Its
> allowing the choice for only those two subarchs.

If you want to make it configurable, I suggest we put it under the
"Processor Support" menu in arch/powerpc/Kconfig like Altivec and SPE.
It is a chip feature rather than board.  And we won't need the two
redundant options then.

- Leo

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Kumar Gala]

On Mar 15, 2007, at 12:39 AM, Li Yang-r58472 wrote:

>> -----Original Message-----
>> From: Kumar Gala [mailto:galak@kernel.crashing.org]
>> Sent: Thursday, March 15, 2007 11:49 AM
>> To: Li Yang-r58472
>> Cc: Tabi Timur-B04825; Phillips Kim-R1AAHA; linuxppc-dev@ozlabs.org
>> Subject: Re: [PATCH][POWERPC] QE: Make QUICC Engine support a
> configurableoption
>>
>>
>> On Mar 14, 2007, at 10:02 PM, Li Yang-r58472 wrote:
>>
>>>> -----Original Message-----
>>>> From: linuxppc-dev-bounces+leoli=freescale.com@ozlabs.org
>>>> [mailto:linuxppc-dev-bounces+leoli=freescale.com@ozlabs.org] On
>>>> Behalf
>>> Of Timur
>>>> Tabi
>>>> Sent: Thursday, March 15, 2007 3:36 AM
>>>> To: Phillips Kim-R1AAHA
>>>> Cc: linuxppc-dev@ozlabs.org
>>>> Subject: Re: [PATCH][POWERPC] QE: Make QUICC Engine support a
>>> configurableoption
>>>>
>>>> Kim Phillips wrote:
>>>>> On Wed, 14 Mar 2007 13:15:05 -0500 (CDT)
>>>>> Kumar Gala <galak@kernel.crashing.org> wrote:
>>>>>
>>>>>>  arch/powerpc/Kconfig                |    8 --------
>>>>>>  arch/powerpc/platforms/83xx/Kconfig |   12 ++++++++++--
>>>>>>  2 files changed, 10 insertions(+), 10 deletions(-)
>>>>>
>>>>> What about 85xx QE support?
>>>>
>>>> Kumar and I talked about it.  85xx support will be added when QE
>>>> works
>>> on 85xx.
>>>> However,
>>>> the patch still needs changes.  To allow each CPU family to have
> its
>>> own QE option,
>>>> we'll
>>>> need to define something like QUICC_ENGINE_83xx and
>>>> QUICC_ENGINE_85xx,
>>> and then
>>>> have
>>>> something like this:
>>>>
>>>> config QUICC_ENGINE
>>>> 	bool
>>>> 	default y if QUICC_ENGINE_83xx || QUICC_ENGINE_85xx
>>>
>>> I don't think we need these new options.  If there are differences
>>> between the two SOC versions, presumably not too many, we can
> address
>>> them in device tree.  It's better to leave the QUICC_ENGINE option
> at
>>> arch/powerpc/Kconfig level, IMHO.
>>
>>
>> The issue isn't dealing with differences between 83xx/85xx.  Its
>> allowing the choice for only those two subarchs.
>
> If you want to make it configurable, I suggest we put it under the
> "Processor Support" menu in arch/powerpc/Kconfig like Altivec and SPE.
> It is a chip feature rather than board.  And we won't need the two
> redundant options then.

Both of those are features of the Core processor, not the platform.

I'd prefer this be a platform option.  (I'm not a fan of the  
duplication, but its minor)

- k

RE: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Li Yang-r58472]

> >>>>>>  arch/powerpc/Kconfig                |    8 --------
> >>>>>>  arch/powerpc/platforms/83xx/Kconfig |   12 ++++++++++--
> >>>>>>  2 files changed, 10 insertions(+), 10 deletions(-)
> >>>>>
> >>>>> What about 85xx QE support?
> >>>>
> >>>> Kumar and I talked about it.  85xx support will be added when QE
> >>>> works
> >>> on 85xx.
> >>>> However,
> >>>> the patch still needs changes.  To allow each CPU family to have
> > its
> >>> own QE option,
> >>>> we'll
> >>>> need to define something like QUICC_ENGINE_83xx and
> >>>> QUICC_ENGINE_85xx,
> >>> and then
> >>>> have
> >>>> something like this:
> >>>>
> >>>> config QUICC_ENGINE
> >>>> 	bool
> >>>> 	default y if QUICC_ENGINE_83xx || QUICC_ENGINE_85xx
> >>>
> >>> I don't think we need these new options.  If there are differences
> >>> between the two SOC versions, presumably not too many, we can
> > address
> >>> them in device tree.  It's better to leave the QUICC_ENGINE option
> > at
> >>> arch/powerpc/Kconfig level, IMHO.
> >>
> >>
> >> The issue isn't dealing with differences between 83xx/85xx.  Its
> >> allowing the choice for only those two subarchs.
> >
> > If you want to make it configurable, I suggest we put it under the
> > "Processor Support" menu in arch/powerpc/Kconfig like Altivec and
SPE.
> > It is a chip feature rather than board.  And we won't need the two
> > redundant options then.
>=20
> Both of those are features of the Core processor, not the platform.
>=20
> I'd prefer this be a platform option.  (I'm not a fan of the
> duplication, but its minor)

Well, that depends on how we define processor.  Is co-processor also a
processor? =20

QE is so generic that can be used across different sub-archs maybe even
archs.  Why doesn't it deserve a place out of "platform support" menu?
An option in the top menu is another choice.

On another thought, it is very unlikely that user chooses a more
expensive chip with QE and won't use it.  So make it non-configurable
and be selected automatically is not a bad idea for me.

- Leo

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Timur Tabi]

Li Yang-r58472 wrote:

> QE is so generic that can be used across different sub-archs maybe even
> archs.  Why doesn't it deserve a place out of "platform support" menu?
> An option in the top menu is another choice.

Yes, but for now, the QE is marketed as an option for a few SOCs.  That 
means that when you select the SOC, you expect to see configuration 
options for that SOC.

> On another thought, it is very unlikely that user chooses a more
> expensive chip with QE and won't use it.  So make it non-configurable
> and be selected automatically is not a bad idea for me.

This was addressed earlier.  On some boards, the QE is not wired to 
anything, so there's no point in enabling it.  Disabling it will prevent 
any unused QE code from becoming part of the kernel.

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Kumar Gala]

Here's the new patch, we will add in the 85xx version once 8568 is
functional.

- k

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 5e1ac10..ae181d3 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -396,11 +396,7 @@ endchoice

 config QUICC_ENGINE
 	bool
-	help
-	  The QUICC Engine (QE) is a new generation of communications
-	  coprocessors on Freescale embedded CPUs (akin to CPM in older chips).
-	  Selecting this option means that you wish to build a kernel
-	  for a machine with a QE coprocessor.
+	default n

 config PPC_PSERIES
 	depends on PPC_MULTIPLATFORM && PPC64
diff --git a/arch/powerpc/platforms/83xx/Kconfig b/arch/powerpc/platforms/83xx/Kconfig
index 713b31a..9e0f457 100644
--- a/arch/powerpc/platforms/83xx/Kconfig
+++ b/arch/powerpc/platforms/83xx/Kconfig
@@ -14,7 +14,6 @@ config MPC8313_RDB
 config MPC832x_MDS
 	bool "Freescale MPC832x MDS"
 	select DEFAULT_UIMAGE
-	select QUICC_ENGINE
 	help
 	  This option enables support for the MPC832x MDS evaluation board.

@@ -41,12 +40,22 @@ config MPC834x_ITX
 config MPC836x_MDS
 	bool "Freescale MPC836x MDS"
 	select DEFAULT_UIMAGE
-	select QUICC_ENGINE
 	help
 	  This option enables support for the MPC836x MDS Processor Board.

 endchoice

+config QUICC_ENGINE_83xx
+	bool "QUICC Engine Support"
+	select QUICC_ENGINE
+	depends on PPC_MPC836x || PPC_MPC832x
+	default y
+	---help---
+	  The QUICC Engine (QE) is a new generation of communications
+	  coprocessors on Freescale embedded CPUs (akin to CPM in older chips).
+	  Selecting this option means that you wish to build a kernel
+	  for a machine with a QE coprocessor.
+
 config PPC_MPC831x
 	bool
 	select PPC_UDBG_16550

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Scott Wood]

On Thu, Mar 15, 2007 at 10:07:31AM -0500, Kumar Gala wrote:
>  config MPC836x_MDS
>  	bool "Freescale MPC836x MDS"
>  	select DEFAULT_UIMAGE
> -	select QUICC_ENGINE
>  	help
>  	  This option enables support for the MPC836x MDS Processor Board.
> 
>  endchoice
> 
> +config QUICC_ENGINE_83xx
> +	bool "QUICC Engine Support"
> +	select QUICC_ENGINE
> +	depends on PPC_MPC836x || PPC_MPC832x
> +	default y
> +	---help---
> +	  The QUICC Engine (QE) is a new generation of communications
> +	  coprocessors on Freescale embedded CPUs (akin to CPM in older chips).
> +	  Selecting this option means that you wish to build a kernel
> +	  for a machine with a QE coprocessor.
> +

Instead of doing it like this, what about having each QE-enabled SOC
select HAS_QUICC_ENGINE, and then have the user-configurable
QUICC_ENGINE option depend on HAS_QUICC_ENGINE?

That way, there's no need for separate 83xx and 85xx defines, and the
knowledge of which SOCs have QE is maintaned with the SOC entry, rather
than in a separate list.

-Scott

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Timur Tabi]

Scott Wood wrote:

>> +config QUICC_ENGINE_83xx
>> +	bool "QUICC Engine Support"
>> +	select QUICC_ENGINE
>> +	depends on PPC_MPC836x || PPC_MPC832x
>> +	default y
>> +	---help---
>> +	  The QUICC Engine (QE) is a new generation of communications
>> +	  coprocessors on Freescale embedded CPUs (akin to CPM in older chips).
>> +	  Selecting this option means that you wish to build a kernel
>> +	  for a machine with a QE coprocessor.
>> +
> 
> Instead of doing it like this, what about having each QE-enabled SOC
> select HAS_QUICC_ENGINE, and then have the user-configurable
> QUICC_ENGINE option depend on HAS_QUICC_ENGINE?

The purpose of doing it this way is that the "QE Support" option appears 
BELOW each SOC option.  So if you pick an 836x, you'll see a menu that 
says "QE support".  You want to have the menu option to disable QE 
support even if the QE is present on the SOC.

We will need to do the same thing with the 8568, when the QE support 
works with it.  At that point, there will be a "QUICC_ENGINE_85xx", 
which will appear on *that* menu.

You cannot have the same config option in more than one Kconfig file.

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Timur Tabi]

Kumar Gala wrote:
> Here's the new patch, we will add in the 85xx version once 8568 is
> functional.

The patch works, but I was wondering if you could move the QE Options (i.e. fast and/or 
slow UCC support) to this same menu?  Right now, that menu appears on the top level. 
Instead, it should just appear on the Platform menu under "QUICC Engine Support".

Also, one thing I did notice is that currently, you can only select platforms, but not 
processors.  Basing QE support on a processor sub-family seems kinda weird, now.  Should 
we expand the 83xx Platforms menu to include specific processors as an option?

-- 
Timur Tabi
Linux Kernel Developer @ Freescale

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Kumar Gala]

On Mar 16, 2007, at 2:21 PM, Timur Tabi wrote:

> Kumar Gala wrote:
>> Here's the new patch, we will add in the 85xx version once 8568 is
>> functional.
>
> The patch works, but I was wondering if you could move the QE  
> Options (i.e. fast and/or slow UCC support) to this same menu?   
> Right now, that menu appears on the top level. Instead, it should  
> just appear on the Platform menu under "QUICC Engine Support".

This will get fixed up as part of my larger arch/powerpc/Kconfig cleanup

> Also, one thing I did notice is that currently, you can only select  
> platforms, but not processors.  Basing QE support on a processor  
> sub-family seems kinda weird, now.  Should we expand the 83xx  
> Platforms menu to include specific processors as an option?

No, right now the platform implies the processor.

- k

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Timur Tabi]

Kumar Gala wrote:
> Here's the new patch, we will add in the 85xx version once 8568 is
> functional.
> 
> - k
> 
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 5e1ac10..ae181d3 100644

Acked-by: Timur Tabi <timur@freescale.com>

-- 
Timur Tabi
Linux Kernel Developer @ Freescale

Re: [PATCH][POWERPC] QE: Make QUICC Engine support a configurableoption

[Timur Tabi]

Kumar Gala wrote:

>> The patch works, but I was wondering if you could move the QE Options 
>> (i.e. fast and/or slow UCC support) to this same menu?  Right now, 
>> that menu appears on the top level. Instead, it should just appear on 
>> the Platform menu under "QUICC Engine Support".
> 
> This will get fixed up as part of my larger arch/powerpc/Kconfig cleanup

Actually, I forgot that my UCC fast/slow Kconfig patch makes the QE Options menu go away 
completely.

-- 
Timur Tabi
Linux Kernel Developer @ Freescale