[PATCH] arm64: enable ARCH_HAS_BANDGAP config

[PATCH] arm64: enable ARCH_HAS_BANDGAP config

[Abhilash Kesavan]

Some of the existing thermal drivers (ti and exynos) have a dependency on
ARCH_HAS_BANDGAP. Activate ARCH_HAS_BANDGAP config entry for ARM64 so that
these drivers may be re-used.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
---
 arch/arm64/Kconfig |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 5bb1900..7c452e4 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -139,6 +139,9 @@ config KERNEL_MODE_NEON
 config FIX_EARLYCON_MEM
 	def_bool y
 
+config ARCH_HAS_BANDGAP
+	def_bool y
+
 source "init/Kconfig"
 
 source "kernel/Kconfig.freezer"
-- 
1.7.9.5

[PATCH] arm64: enable ARCH_HAS_BANDGAP config

[Alim Akhtar]

Hi Abhilash,

On Fri, Nov 14, 2014 at 6:00 PM, Abhilash Kesavan <a.kesavan@samsung.com> wrote:
> Some of the existing thermal drivers (ti and exynos) have a dependency on
> ARCH_HAS_BANDGAP. Activate ARCH_HAS_BANDGAP config entry for ARM64 so that
> these drivers may be re-used.
>
> Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
> ---
HAS_BANDGAP was added to ARM to indicate that arch supports a bandgap
device like a thermal management unit, so this looks good to me.

Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>

>  arch/arm64/Kconfig |    3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 5bb1900..7c452e4 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -139,6 +139,9 @@ config KERNEL_MODE_NEON
>  config FIX_EARLYCON_MEM
>         def_bool y
>
> +config ARCH_HAS_BANDGAP
> +       def_bool y
> +
>  source "init/Kconfig"
>
>  source "kernel/Kconfig.freezer"
> --
> 1.7.9.5
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel



-- 
Regards,
Alim

[PATCH] arm64: enable ARCH_HAS_BANDGAP config

[Catalin Marinas]

On Sun, Nov 23, 2014 at 08:05:05AM +0000, Alim Akhtar wrote:
> On Fri, Nov 14, 2014 at 6:00 PM, Abhilash Kesavan <a.kesavan@samsung.com> wrote:
> > Some of the existing thermal drivers (ti and exynos) have a dependency on
> > ARCH_HAS_BANDGAP. Activate ARCH_HAS_BANDGAP config entry for ARM64 so that
> > these drivers may be re-used.
> >
> > Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
> > ---
> HAS_BANDGAP was added to ARM to indicate that arch supports a bandgap
> device like a thermal management unit, so this looks good to me.

But it doesn't look good to me. ARCH_HAS_* kind of implies that the
architecture has some feature or the port provides some feature. But in
the current use, it simply allows the enabling of the menu config
entries for two drivers (EXYNOS_THERMAL and TI_SOC_THERMAL).

If you want to specify that the SoC has a device, just use DT and not
some random config option that only enables the menu entry for the
corresponding driver.

-- 
Catalin

[PATCH] arm64: enable ARCH_HAS_BANDGAP config

[Abhilash Kesavan]

Hi Catalin,

On Fri, Nov 28, 2014 at 7:42 PM, Catalin Marinas
<catalin.marinas@arm.com> wrote:
> On Sun, Nov 23, 2014 at 08:05:05AM +0000, Alim Akhtar wrote:
>> On Fri, Nov 14, 2014 at 6:00 PM, Abhilash Kesavan <a.kesavan@samsung.com> wrote:
>> > Some of the existing thermal drivers (ti and exynos) have a dependency on
>> > ARCH_HAS_BANDGAP. Activate ARCH_HAS_BANDGAP config entry for ARM64 so that
>> > these drivers may be re-used.
>> >
>> > Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
>> > ---
>> HAS_BANDGAP was added to ARM to indicate that arch supports a bandgap
>> device like a thermal management unit, so this looks good to me.
>
> But it doesn't look good to me. ARCH_HAS_* kind of implies that the
> architecture has some feature or the port provides some feature. But in
> the current use, it simply allows the enabling of the menu config
> entries for two drivers (EXYNOS_THERMAL and TI_SOC_THERMAL).
>
> If you want to specify that the SoC has a device, just use DT and not
> some random config option that only enables the menu entry for the
> corresponding driver.

So, you are suggesting that the ARCH_HAS_BANDGAP dependency for these
two drivers be removed ? I am not aware of the history behind adding
this symbol, but as it is only used  by the 2 platforms it should be
easy to remove.

Regards,
Abhilash
>
> --
> Catalin

[PATCH] arm64: enable ARCH_HAS_BANDGAP config

[Catalin Marinas]

On Fri, Nov 28, 2014 at 02:39:09PM +0000, Abhilash Kesavan wrote:
> On Fri, Nov 28, 2014 at 7:42 PM, Catalin Marinas
> <catalin.marinas@arm.com> wrote:
> > On Sun, Nov 23, 2014 at 08:05:05AM +0000, Alim Akhtar wrote:
> >> On Fri, Nov 14, 2014 at 6:00 PM, Abhilash Kesavan <a.kesavan@samsung.com> wrote:
> >> > Some of the existing thermal drivers (ti and exynos) have a dependency on
> >> > ARCH_HAS_BANDGAP. Activate ARCH_HAS_BANDGAP config entry for ARM64 so that
> >> > these drivers may be re-used.
> >> >
> >> > Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
> >> > ---
> >> HAS_BANDGAP was added to ARM to indicate that arch supports a bandgap
> >> device like a thermal management unit, so this looks good to me.
> >
> > But it doesn't look good to me. ARCH_HAS_* kind of implies that the
> > architecture has some feature or the port provides some feature. But in
> > the current use, it simply allows the enabling of the menu config
> > entries for two drivers (EXYNOS_THERMAL and TI_SOC_THERMAL).
> >
> > If you want to specify that the SoC has a device, just use DT and not
> > some random config option that only enables the menu entry for the
> > corresponding driver.
> 
> So, you are suggesting that the ARCH_HAS_BANDGAP dependency for these
> two drivers be removed ? I am not aware of the history behind adding
> this symbol, but as it is only used  by the 2 platforms it should be
> easy to remove.

Yes. You have defconfig for those platforms anyway. If you only want to
enable a driver for a certain SoC, put a dependency on that SoC config
(it doesn't look like some generic driver that is used by multiple
SoCs).

-- 
Catalin

[PATCH] arm64: enable ARCH_HAS_BANDGAP config

[Alim Akhtar]

Hi Catalin,

On Fri, Nov 28, 2014 at 7:42 PM, Catalin Marinas
<catalin.marinas@arm.com> wrote:
> On Sun, Nov 23, 2014 at 08:05:05AM +0000, Alim Akhtar wrote:
>> On Fri, Nov 14, 2014 at 6:00 PM, Abhilash Kesavan <a.kesavan@samsung.com> wrote:
>> > Some of the existing thermal drivers (ti and exynos) have a dependency on
>> > ARCH_HAS_BANDGAP. Activate ARCH_HAS_BANDGAP config entry for ARM64 so that
>> > these drivers may be re-used.
>> >
>> > Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
>> > ---
>> HAS_BANDGAP was added to ARM to indicate that arch supports a bandgap
>> device like a thermal management unit, so this looks good to me.
>
> But it doesn't look good to me. ARCH_HAS_* kind of implies that the
> architecture has some feature or the port provides some feature. But in
> the current use, it simply allows the enabling of the menu config
> entries for two drivers (EXYNOS_THERMAL and TI_SOC_THERMAL).
>
> If you want to specify that the SoC has a device, just use DT and not
> some random config option that only enables the menu entry for the
> corresponding driver.
>
Well completely agree with you.
Not sure why this was done for ARM though.
> --
> Catalin



-- 
Regards,
Alim