| Message ID | 1442752251-20744-6-git-send-email-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Sep 20, 2015 at 8:30 PM, Hans de Goede <hdegoede@redhat.com> wrote: > All A13 based q8 formfactor tablets use the same backlight setup, add > a backlight devicetree node for controlling the backlight on these devices. > > Signed-off-by: Hans de Goede <hdegoede@redhat.com> > --- > arch/arm/boot/dts/sun5i-q8-common.dtsi | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/arch/arm/boot/dts/sun5i-q8-common.dtsi b/arch/arm/boot/dts/sun5i-q8-common.dtsi > index 0641d68..76a5204 100644 > --- a/arch/arm/boot/dts/sun5i-q8-common.dtsi > +++ b/arch/arm/boot/dts/sun5i-q8-common.dtsi > @@ -41,11 +41,22 @@ > */ > #include "sunxi-q8-common.dtsi" > > +#include <dt-bindings/pwm/pwm.h> > + > / { > aliases { > serial0 = &uart1; > }; > > + backlight: backlight { > + compatible = "pwm-backlight"; > + pwms = <&pwm 0 50000 PWM_POLARITY_INVERTED>; > + brightness-levels = <0 10 20 30 40 50 60 70 80 90 100>; > + default-brightness-level = <8>; > + /* TODO: backlight uses axp gpio1 as enable pin */ > + /* TODO: backlight is powered by AXP209 DCDC1SW */ There's no DCDC1SW on AXP209. The reference design shows the backlight regulator is powered directly from IPSOUT, but the PWM pullup is powered by LCD-VCC, which itself is enabled by AXP209 GPIO0. Would that be the case, or maybe closer, given we don't have schematics? Regards ChenYu > + }; > + > chosen { > stdout-path = "serial0:115200n8"; > }; > -- > 2.4.3 >
Hi, On 09/20/2015 10:46 AM, Chen-Yu Tsai wrote: > On Sun, Sep 20, 2015 at 8:30 PM, Hans de Goede <hdegoede@redhat.com> wrote: >> All A13 based q8 formfactor tablets use the same backlight setup, add >> a backlight devicetree node for controlling the backlight on these devices. >> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >> --- >> arch/arm/boot/dts/sun5i-q8-common.dtsi | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/arch/arm/boot/dts/sun5i-q8-common.dtsi b/arch/arm/boot/dts/sun5i-q8-common.dtsi >> index 0641d68..76a5204 100644 >> --- a/arch/arm/boot/dts/sun5i-q8-common.dtsi >> +++ b/arch/arm/boot/dts/sun5i-q8-common.dtsi >> @@ -41,11 +41,22 @@ >> */ >> #include "sunxi-q8-common.dtsi" >> >> +#include <dt-bindings/pwm/pwm.h> >> + >> / { >> aliases { >> serial0 = &uart1; >> }; >> >> + backlight: backlight { >> + compatible = "pwm-backlight"; >> + pwms = <&pwm 0 50000 PWM_POLARITY_INVERTED>; >> + brightness-levels = <0 10 20 30 40 50 60 70 80 90 100>; >> + default-brightness-level = <8>; >> + /* TODO: backlight uses axp gpio1 as enable pin */ >> + /* TODO: backlight is powered by AXP209 DCDC1SW */ > > There's no DCDC1SW on AXP209. The reference design shows the backlight > regulator is powered directly from IPSOUT, Ah, right, I'll do a v2 dropping this comment line. > but the PWM pullup is powered > by LCD-VCC, which itself is enabled by AXP209 GPIO0. > > Would that be the case, or maybe closer, given we don't have schematics? gpio0 needs to be driven high to get the backlight to lite up, that is pretty much all I know. Regards, Hans
Hi, On 09/20/2015 11:14 AM, Hans de Goede wrote: > Hi, > > On 09/20/2015 10:46 AM, Chen-Yu Tsai wrote: >> On Sun, Sep 20, 2015 at 8:30 PM, Hans de Goede <hdegoede@redhat.com> wrote: >>> All A13 based q8 formfactor tablets use the same backlight setup, add >>> a backlight devicetree node for controlling the backlight on these devices. >>> >>> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >>> --- >>> arch/arm/boot/dts/sun5i-q8-common.dtsi | 11 +++++++++++ >>> 1 file changed, 11 insertions(+) >>> >>> diff --git a/arch/arm/boot/dts/sun5i-q8-common.dtsi b/arch/arm/boot/dts/sun5i-q8-common.dtsi >>> index 0641d68..76a5204 100644 >>> --- a/arch/arm/boot/dts/sun5i-q8-common.dtsi >>> +++ b/arch/arm/boot/dts/sun5i-q8-common.dtsi >>> @@ -41,11 +41,22 @@ >>> */ >>> #include "sunxi-q8-common.dtsi" >>> >>> +#include <dt-bindings/pwm/pwm.h> >>> + >>> / { >>> aliases { >>> serial0 = &uart1; >>> }; >>> >>> + backlight: backlight { >>> + compatible = "pwm-backlight"; >>> + pwms = <&pwm 0 50000 PWM_POLARITY_INVERTED>; >>> + brightness-levels = <0 10 20 30 40 50 60 70 80 90 100>; >>> + default-brightness-level = <8>; >>> + /* TODO: backlight uses axp gpio1 as enable pin */ >>> + /* TODO: backlight is powered by AXP209 DCDC1SW */ >> >> There's no DCDC1SW on AXP209. The reference design shows the backlight >> regulator is powered directly from IPSOUT, > > Ah, right, I'll do a v2 dropping this comment line. > > > but the PWM pullup is powered >> by LCD-VCC, which itself is enabled by AXP209 GPIO0. >> >> Would that be the case, or maybe closer, given we don't have schematics? > > gpio0 needs to be driven high to get the backlight to lite up, that > is pretty much all I know. Correction, gpio1. I guess that pullup is only there to keep the backlight off while the pwm pin is still muxed as input, rather then pwm-output. Regards, Hans
> + default-brightness-level = <8>;
Why?
Is not better 100% ?
Silviop
On Sat, Dec 19, 2015 at 6:54 PM, <8001010@gmail.com> wrote: >> + default-brightness-level = <8>; > > > Why? > Is not better 100% ? It's just an arbitrary value. Plus having the backlight at 100% on battery powered devices might eat up the battery quicker. ChenYu
diff --git a/arch/arm/boot/dts/sun5i-q8-common.dtsi b/arch/arm/boot/dts/sun5i-q8-common.dtsi index 0641d68..76a5204 100644 --- a/arch/arm/boot/dts/sun5i-q8-common.dtsi +++ b/arch/arm/boot/dts/sun5i-q8-common.dtsi @@ -41,11 +41,22 @@ */ #include "sunxi-q8-common.dtsi" +#include <dt-bindings/pwm/pwm.h> + / { aliases { serial0 = &uart1; }; + backlight: backlight { + compatible = "pwm-backlight"; + pwms = <&pwm 0 50000 PWM_POLARITY_INVERTED>; + brightness-levels = <0 10 20 30 40 50 60 70 80 90 100>; + default-brightness-level = <8>; + /* TODO: backlight uses axp gpio1 as enable pin */ + /* TODO: backlight is powered by AXP209 DCDC1SW */ + }; + chosen { stdout-path = "serial0:115200n8"; };
All A13 based q8 formfactor tablets use the same backlight setup, add a backlight devicetree node for controlling the backlight on these devices. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- arch/arm/boot/dts/sun5i-q8-common.dtsi | 11 +++++++++++ 1 file changed, 11 insertions(+)