[RFC PATCH 0/3] ARM: OMAP2+: Add command line parameter for debugSS module control

[RFC PATCH 0/3] ARM: OMAP2+: Add command line parameter for debugSS module control

[hvaibhav]

From: Vaibhav Hiremath <hvaibhav@ti.com>

Currently there is no clean mechanism to control debugSS module and
you have to always keep clocks enabled, either,

    - By enabling it during boot as part of clk_init function
      (post common-clock migration).
    Or
    - By having HWMOD_INIT_NO_IDLE flag in hwmod data
      (Joel submitted patch for AM335x earlier).

Based on the discussion with Kevin H,
http://www.mail-archive.com/linux-omap@vger.kernel.org/msg81771.html

This patch introduces new kernel parameter "omap_debugss_en",
which will allow user to control debugSS module enable/disable
part during boot-time.

In case of OMAP3, the debugSS is part of EMU domain and
is currently controlled by clock tree alone.

In case of OMAP4, the debugSS is part of EMU domain and
is currently controlled by clock tree, as MODULEMODE_SWCTRL
is not defined for hwmod.

In case of AM335x, the debugSS is in wakeup domain and is currently
controlled through hwmod alone. Currently we keep it always enabled.

Testing:
	- Tested on AM335x based EVM and BeagleBone platform

	  As required, without this flag the debugSS module will be disabled
	  during kernel boot.

OMAP (2/3/4) may require some changes from clock/hwmod perspective
in order to use this new parameter.
I am still looking into OMAP spec and this RFC version of patch-series
is to get comments or opinion from list.

Vaibhav Hiremath (3):
  ARM: AM33XX: clock: Add debugSS clock nodes to clock tree
  ARM: AM33XX: hwmod: Add hwmod data for debugSS
  ARM: OMAP2+: Add command line parameter for debugSS module control

 Documentation/kernel-parameters.txt        |    3 +
 arch/arm/mach-omap2/Makefile               |    2 +-
 arch/arm/mach-omap2/cclock33xx_data.c      |   47 +++++++++++++++--
 arch/arm/mach-omap2/debugss.c              |   80 ++++++++++++++++++++++++++++
 arch/arm/mach-omap2/omap_hwmod_33xx_data.c |   69 ++++++++++++++++--------
 5 files changed, 173 insertions(+), 28 deletions(-)
 create mode 100644 arch/arm/mach-omap2/debugss.c

RE: [RFC PATCH 0/3] ARM: OMAP2+: Add command line parameter for debugSS module control

[Hiremath, Vaibhav]

> -----Original Message-----
> From: Hiremath, Vaibhav
> Sent: Monday, March 04, 2013 5:06 PM
> To: linux-omap@vger.kernel.org
> Cc: tony@atomide.com; khilman@linaro.org; paul@pwsan.com; Nayak,
> Rajendra; linux-arm-kernel@lists.infradead.org; Hiremath, Vaibhav
> Subject: [RFC PATCH 0/3] ARM: OMAP2+: Add command line parameter for
> debugSS module control
> 
> From: Vaibhav Hiremath <hvaibhav@ti.com>
> 
> Currently there is no clean mechanism to control debugSS module and
> you have to always keep clocks enabled, either,
> 
>     - By enabling it during boot as part of clk_init function
>       (post common-clock migration).
>     Or
>     - By having HWMOD_INIT_NO_IDLE flag in hwmod data
>       (Joel submitted patch for AM335x earlier).
> 
> Based on the discussion with Kevin H,
> http://www.mail-archive.com/linux-omap@vger.kernel.org/msg81771.html
> 
> This patch introduces new kernel parameter "omap_debugss_en",
> which will allow user to control debugSS module enable/disable
> part during boot-time.
> 
> In case of OMAP3, the debugSS is part of EMU domain and
> is currently controlled by clock tree alone.
> 
> In case of OMAP4, the debugSS is part of EMU domain and
> is currently controlled by clock tree, as MODULEMODE_SWCTRL
> is not defined for hwmod.
> 
> In case of AM335x, the debugSS is in wakeup domain and is currently
> controlled through hwmod alone. Currently we keep it always enabled.
> 
> Testing:
> 	- Tested on AM335x based EVM and BeagleBone platform
> 
> 	  As required, without this flag the debugSS module will be
> disabled
> 	  during kernel boot.
> 
> OMAP (2/3/4) may require some changes from clock/hwmod perspective
> in order to use this new parameter.
> I am still looking into OMAP spec and this RFC version of patch-series
> is to get comments or opinion from list.
> 
> Vaibhav Hiremath (3):
>   ARM: AM33XX: clock: Add debugSS clock nodes to clock tree
>   ARM: AM33XX: hwmod: Add hwmod data for debugSS
>   ARM: OMAP2+: Add command line parameter for debugSS module control
> 
>  Documentation/kernel-parameters.txt        |    3 +
>  arch/arm/mach-omap2/Makefile               |    2 +-
>  arch/arm/mach-omap2/cclock33xx_data.c      |   47 +++++++++++++++--
>  arch/arm/mach-omap2/debugss.c              |   80
> ++++++++++++++++++++++++++++
>  arch/arm/mach-omap2/omap_hwmod_33xx_data.c |   69 ++++++++++++++++----
> ----
>  5 files changed, 173 insertions(+), 28 deletions(-)
>  create mode 100644 arch/arm/mach-omap2/debugss.c

Kevin/Tony,

Any comments or input on this patch series?

Thanks,
Vaibhav

Re: [RFC PATCH 0/3] ARM: OMAP2+: Add command line parameter for debugSS module control

[Tony Lindgren]

* Hiremath, Vaibhav <hvaibhav@ti.com> [130314 04:33]:
> > From: Hiremath, Vaibhav
> > This patch introduces new kernel parameter "omap_debugss_en",
> > which will allow user to control debugSS module enable/disable
> > part during boot-time.
> > 
> > In case of OMAP3, the debugSS is part of EMU domain and
> > is currently controlled by clock tree alone.
> > 
> > In case of OMAP4, the debugSS is part of EMU domain and
> > is currently controlled by clock tree, as MODULEMODE_SWCTRL
> > is not defined for hwmod.
> > 
> > In case of AM335x, the debugSS is in wakeup domain and is currently
> > controlled through hwmod alone. Currently we keep it always enabled.
> 
> Any comments or input on this patch series?

No comments on adding the clocks, but the enabling of
them should be just a regular device driver.

Regards,

Tony

RE: [RFC PATCH 0/3] ARM: OMAP2+: Add command line parameter for debugSS module control

[Hiremath, Vaibhav]

> -----Original Message-----
> From: Tony Lindgren [mailto:tony@atomide.com]
> Sent: Monday, April 08, 2013 11:01 PM
> To: Hiremath, Vaibhav
> Cc: linux-omap@vger.kernel.org; khilman@linaro.org; paul@pwsan.com;
> Nayak, Rajendra; linux-arm-kernel@lists.infradead.org
> Subject: Re: [RFC PATCH 0/3] ARM: OMAP2+: Add command line parameter
> for debugSS module control
> 
> * Hiremath, Vaibhav <hvaibhav@ti.com> [130314 04:33]:
> > > From: Hiremath, Vaibhav
> > > This patch introduces new kernel parameter "omap_debugss_en",
> > > which will allow user to control debugSS module enable/disable
> > > part during boot-time.
> > >
> > > In case of OMAP3, the debugSS is part of EMU domain and
> > > is currently controlled by clock tree alone.
> > >
> > > In case of OMAP4, the debugSS is part of EMU domain and
> > > is currently controlled by clock tree, as MODULEMODE_SWCTRL
> > > is not defined for hwmod.
> > >
> > > In case of AM335x, the debugSS is in wakeup domain and is currently
> > > controlled through hwmod alone. Currently we keep it always
> enabled.
> >
> > Any comments or input on this patch series?
> 
> No comments on adding the clocks, but the enabling of
> them should be just a regular device driver.
> 

Thanks for review, on this patch I will add your Reviewed-by line on next version
Of the patch-series.

I have just responded my comment to the other mail on this, and based on
Your response we can conclude. 

Thanks,
Vaibhav
.