| Message ID | 1363719573-20926-7-git-send-email-achew@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Dear Andrew Chew, > The pwm-backlight driver now takes a mandatory regulator that is gotten > during driver probe. Initialize a dummy regulator to satisfy this > requirement. > > Signed-off-by: Andrew Chew <achew@nvidia.com> Do we really need a mandatory regulator? Why can't it be optional? Best regards, Marek Vasut -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 03/19/2013 03:27 PM, Marek Vasut wrote: > Dear Andrew Chew, > >> The pwm-backlight driver now takes a mandatory regulator that is gotten >> during driver probe. Initialize a dummy regulator to satisfy this >> requirement. >> >> Signed-off-by: Andrew Chew <achew@nvidia.com> > > Do we really need a mandatory regulator? Why can't it be optional? IIRC, the previous advice I've seen is that if a device (driver) uses a regulator, it must /require/ a regulator, and if a particular board doesn't actually have a SW-controlled regulator, then a fixed- or dummy- regulator should be provided to satisfy this requirement. CC'ing Mark Brown to make sure I really do Recall Correctly. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Mar 19, 2013 at 11:59:30AM -0700, Andrew Chew wrote: > The pwm-backlight driver now takes a mandatory regulator that is gotten > during driver probe. Initialize a dummy regulator to satisfy this > requirement. > > Signed-off-by: Andrew Chew <achew@nvidia.com> > --- > arch/arm/boot/dts/imx23-evk.dts | 6 ++++++ > arch/arm/boot/dts/imx28-apf28dev.dts | 6 ++++++ > arch/arm/boot/dts/imx28-cfa10049.dts | 6 ++++++ > arch/arm/boot/dts/imx28-evk.dts | 6 ++++++ > arch/arm/boot/dts/imx28-tx28.dts | 6 ++++++ > 5 files changed, 30 insertions(+) > > diff --git a/arch/arm/boot/dts/imx23-evk.dts b/arch/arm/boot/dts/imx23-evk.dts > index 035c13f..e48e36c 100644 > --- a/arch/arm/boot/dts/imx23-evk.dts > +++ b/arch/arm/boot/dts/imx23-evk.dts > @@ -97,10 +97,16 @@ > }; > }; > > + bl_en: fixed-regulator { The node name is too generic. Very likely we have other fixed regulator in a dts. For mxs, we have all such board level regulators defined in node "regulators" as children. Shawn > + compatible = "regulator-fixed"; > + regulator-name = "bl-en-supply"; > + }; > + > backlight { > compatible = "pwm-backlight"; > pwms = <&pwm 2 5000000>; > brightness-levels = <0 4 8 16 32 64 128 255>; > default-brightness-level = <6>; > + enable-supply = <&bl_en>; > }; > }; -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Mark, > On Tue, Mar 19, 2013 at 04:10:26PM -0600, Stephen Warren wrote: > > On 03/19/2013 03:27 PM, Marek Vasut wrote: > > > Do we really need a mandatory regulator? Why can't it be optional? > > > > IIRC, the previous advice I've seen is that if a device (driver) uses a > > regulator, it must /require/ a regulator, and if a particular board > > doesn't actually have a SW-controlled regulator, then a fixed- or dummy- > > regulator should be provided to satisfy this requirement. > > > > CC'ing Mark Brown to make sure I really do Recall Correctly. > > Yes, and it should be fixed rather than dummy. The issue is partly that > it's probably important that the device has power so we don't want to > just ignore errors and partly that this is something which applies to > essentially all devices so whatever we do for this case ought to be done > by the core so all devices can benefit and we don't have to duplicate > lots of code in individual drivers. Thanks for clearing this! Best regards, Marek Vasut -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/boot/dts/imx23-evk.dts b/arch/arm/boot/dts/imx23-evk.dts index 035c13f..e48e36c 100644 --- a/arch/arm/boot/dts/imx23-evk.dts +++ b/arch/arm/boot/dts/imx23-evk.dts @@ -97,10 +97,16 @@ }; }; + bl_en: fixed-regulator { + compatible = "regulator-fixed"; + regulator-name = "bl-en-supply"; + }; + backlight { compatible = "pwm-backlight"; pwms = <&pwm 2 5000000>; brightness-levels = <0 4 8 16 32 64 128 255>; default-brightness-level = <6>; + enable-supply = <&bl_en>; }; }; diff --git a/arch/arm/boot/dts/imx28-apf28dev.dts b/arch/arm/boot/dts/imx28-apf28dev.dts index 6d8865b..866e26f 100644 --- a/arch/arm/boot/dts/imx28-apf28dev.dts +++ b/arch/arm/boot/dts/imx28-apf28dev.dts @@ -144,11 +144,17 @@ }; }; + bl_en: fixed-regulator { + compatible = "regulator-fixed"; + regulator-name = "bl-en-supply"; + }; + backlight { compatible = "pwm-backlight"; pwms = <&pwm 3 191000>; brightness-levels = <0 4 8 16 32 64 128 255>; default-brightness-level = <6>; + enable-supply = <&bl_en>; }; }; diff --git a/arch/arm/boot/dts/imx28-cfa10049.dts b/arch/arm/boot/dts/imx28-cfa10049.dts index a0d3e9f..a8477b6 100644 --- a/arch/arm/boot/dts/imx28-cfa10049.dts +++ b/arch/arm/boot/dts/imx28-cfa10049.dts @@ -299,10 +299,16 @@ rotary-encoder,relative-axis; }; + bl_en: fixed-regulator { + compatible = "regulator-fixed"; + regulator-name = "bl-en-supply"; + }; + backlight { compatible = "pwm-backlight"; pwms = <&pwm 3 5000000>; brightness-levels = <0 4 8 16 32 64 128 255>; default-brightness-level = <6>; + enable-supply = <&bl_en>; }; }; diff --git a/arch/arm/boot/dts/imx28-evk.dts b/arch/arm/boot/dts/imx28-evk.dts index 2da316e..810f1e4 100644 --- a/arch/arm/boot/dts/imx28-evk.dts +++ b/arch/arm/boot/dts/imx28-evk.dts @@ -307,10 +307,16 @@ }; }; + bl_en: fixed-regulator { + compatible = "regulator-fixed"; + regulator-name = "bl-en-supply"; + }; + backlight { compatible = "pwm-backlight"; pwms = <&pwm 2 5000000>; brightness-levels = <0 4 8 16 32 64 128 255>; default-brightness-level = <6>; + enable-supply = <&bl_en>; }; }; diff --git a/arch/arm/boot/dts/imx28-tx28.dts b/arch/arm/boot/dts/imx28-tx28.dts index 37be532..ea3c88a 100644 --- a/arch/arm/boot/dts/imx28-tx28.dts +++ b/arch/arm/boot/dts/imx28-tx28.dts @@ -107,10 +107,16 @@ }; }; + bl_en: fixed-regulator { + compatible = "regulator-fixed"; + regulator-name = "bl-en-supply"; + }; + backlight { compatible = "pwm-backlight"; pwms = <&pwm 0 5000000>; brightness-levels = <0 4 8 16 32 64 128 255>; default-brightness-level = <6>; + enable-supply = <&bl_en>; }; };
The pwm-backlight driver now takes a mandatory regulator that is gotten during driver probe. Initialize a dummy regulator to satisfy this requirement. Signed-off-by: Andrew Chew <achew@nvidia.com> --- arch/arm/boot/dts/imx23-evk.dts | 6 ++++++ arch/arm/boot/dts/imx28-apf28dev.dts | 6 ++++++ arch/arm/boot/dts/imx28-cfa10049.dts | 6 ++++++ arch/arm/boot/dts/imx28-evk.dts | 6 ++++++ arch/arm/boot/dts/imx28-tx28.dts | 6 ++++++ 5 files changed, 30 insertions(+)