[PATCH 0/1] OMAP: TWL: set clk32kg regulator on

[PATCH 0/1] OMAP: TWL: set clk32kg regulator on

[Vishal Mahaveer]

Set constraint always_on for clk32kg regulator.
This regulator is used by connectivity chip (wl12xx) on OMAP platforms.

Vishal Mahaveer (1):
  OMAP: TWL: set clk32kg regulator on

 arch/arm/mach-omap2/twl-common.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

[PATCH 1/1] OMAP: TWL: set clk32kg regulator on

[Vishal Mahaveer]

omap4_clk32kg regulator is used by connectivity (WLAN/BT/GPS) chip on
omap4 platforms.
Set always_on flag to true for connectivity chip to operate.

Signed-off-by: Vishal Mahaveer <vishalm@ti.com>
---
 arch/arm/mach-omap2/twl-common.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-omap2/twl-common.c b/arch/arm/mach-omap2/twl-common.c
index 5224357..8910cea 100644
--- a/arch/arm/mach-omap2/twl-common.c
+++ b/arch/arm/mach-omap2/twl-common.c
@@ -270,6 +270,7 @@ static struct regulator_init_data omap4_vusb_idata = {
 static struct regulator_init_data omap4_clk32kg_idata = {
 	.constraints = {
 		.valid_ops_mask		= REGULATOR_CHANGE_STATUS,
+		.always_on		= true,
 	},
 };
 
-- 
1.7.0.4

Re: [PATCH 1/1] OMAP: TWL: set clk32kg regulator on

[Kevin Hilman]

Vishal Mahaveer <vishalm@ti.com> writes:

> omap4_clk32kg regulator is used by connectivity (WLAN/BT/GPS) chip on
> omap4 platforms.
> Set always_on flag to true for connectivity chip to operate.

The driver/init for the connectivity chip should be using the regulator
API to enable/disable the regulator as needed.

Kevin

RE: [PATCH 1/1] OMAP: TWL: set clk32kg regulator on

[Mahaveer, Vishal]

>> omap4_clk32kg regulator is used by connectivity (WLAN/BT/GPS) chip on
>> omap4 platforms.
>> Set always_on flag to true for connectivity chip to operate.
>
> The driver/init for the connectivity chip should be using the regulator
> API to enable/disable the regulator as needed.

The connectivity chip is used for BT, WLAN, FM and GPS. So we want it on at all times.

Re: [PATCH 1/1] OMAP: TWL: set clk32kg regulator on

[Kevin Hilman]

"Mahaveer, Vishal" <vishalm@ti.com> writes:

>>> omap4_clk32kg regulator is used by connectivity (WLAN/BT/GPS) chip on
>>> omap4 platforms.
>>> Set always_on flag to true for connectivity chip to operate.
>>
>> The driver/init for the connectivity chip should be using the regulator
>> API to enable/disable the regulator as needed.
>
> The connectivity chip is used for BT, WLAN, FM and GPS. So we want it
> on at all times.

No.

You want it on only

1) if the connectivity chip is present, *and*
2) BT, WLAN, FM or GPS are being used.

The current patch assumes that a connectivity chip is present whenever
the TWL is present, which may be true on the platform you're currently
working on, but is not true in general.

And, even if it were present, for power reasons the regulator should be
enabled only when it's needed, not because it might be needed.  That
means that the device-specific (or board specific) code should be
configuring the regulators used for the various modules so the drivers
can request the regulators when they're needed.

Kevin

RE: [PATCH 1/1] OMAP: TWL: set clk32kg regulator on

[Mahaveer, Vishal]

Hilman, Kevin wrote:
> 
> No.
> 
> You want it on only
> 
> 1) if the connectivity chip is present, *and*
> 2) BT, WLAN, FM or GPS are being used.
> 
> The current patch assumes that a connectivity chip is present
> whenever the TWL is present, which may be true on the platform you're
> currently working on, but is not true in general.  
> 
> And, even if it were present, for power reasons the regulator should
> be enabled only when it's needed, not because it might be needed. 
> That means that the device-specific (or board specific) code should
> be configuring the regulators used for the various modules so the
> drivers can request the regulators when they're needed.    
> 
> Kevin

Will it make more sense to move clk32 regulator initialization to board-xxx files of platforms which has the connectivity chip?

- Vishal

Re: [PATCH 1/1] OMAP: TWL: set clk32kg regulator on

[Kevin Hilman]

"Mahaveer, Vishal" <vishalm@ti.com> writes:

> Hilman, Kevin wrote:
>> 
>> No.
>> 
>> You want it on only
>> 
>> 1) if the connectivity chip is present, *and*
>> 2) BT, WLAN, FM or GPS are being used.
>> 
>> The current patch assumes that a connectivity chip is present
>> whenever the TWL is present, which may be true on the platform you're
>> currently working on, but is not true in general.  
>> 
>> And, even if it were present, for power reasons the regulator should
>> be enabled only when it's needed, not because it might be needed. 
>> That means that the device-specific (or board specific) code should
>> be configuring the regulators used for the various modules so the
>> drivers can request the regulators when they're needed.    
>> 
>
> Will it make more sense to move clk32 regulator initialization to
> board-xxx files of platforms which has the connectivity chip?

Yes, initialization should be done only when connectivity chip is
present.

But more importantly, it's the usage of the regulator API that is
important.  My primary objection to this patch is the use of 'always
on', where the drivers/devices that depend on this regulator are the
ones that should be requesting it to be on using the regulator API.

Kevin

RE: [PATCH 1/1] OMAP: TWL: set clk32kg regulator on

[Mahaveer, Vishal]

Hilman, Kevin wrote:
> "Mahaveer, Vishal" <vishalm@ti.com> writes:
> 
>> Hilman, Kevin wrote:
>>> 
>>> No.
>>> 
>>> You want it on only
>>> 
>>> 1) if the connectivity chip is present, *and*
>>> 2) BT, WLAN, FM or GPS are being used.
>>> 
>>> The current patch assumes that a connectivity chip is present
>>> whenever the TWL is present, which may be true on the platform
>>> you're currently working on, but is not true in general.
>>> 
>>> And, even if it were present, for power reasons the regulator should
>>> be enabled only when it's needed, not because it might be needed.
>>> That means that the device-specific (or board specific) code should
>>> be configuring the regulators used for the various modules so the
>>> drivers can request the regulators when they're needed.
>>> 
>> 
>> Will it make more sense to move clk32 regulator initialization to
>> board-xxx files of platforms which has the connectivity chip?
> 
> Yes, initialization should be done only when connectivity chip is
> present. 
> 
> But more importantly, it's the usage of the regulator API that is
> important.  My primary objection to this patch is the use of 'always
> on', where the drivers/devices that depend on this regulator are the
> ones that should be requesting it to be on using the regulator API.   
> 
> Kevin

Understood...

1) clk32kg regulator should be initialized in platform file (boazrd file)
2) Use regulator APIs in connectivity driver to enable it.

- Vishal