| Message ID | 1421749355-23050-1-git-send-email-r63905@freescale.com |
|---|---|
| State | Not Applicable |
| Headers | show |
Am Dienstag, den 20.01.2015, 19:38 +0800 schrieb Shawn Guo: > Add LAKML and a few interested people. > > Shawn > > On Tue, Jan 20, 2015 at 06:22:35PM +0800, Robby Cai wrote: > > Hannstar XGA panel is used by default on i.MX6QDL Sabre Auto/Lite/SD > > or derived board. > > > > According to its data sheet [1], > > a) the dimming duty cycle is 20% - 100%. > > This patch changes the brightness-level from 20 to 100 with step 10 to > > make it straight-forward. > > b) the typical dimming frequency is 20KHz. > > The previous setting is 200Hz. This patch corrects it. > > > > [1] > > http://boundarydevices.com/wp-content/uploads/2013/06/HSD100PXN1-A00-C11-1.0.pdf > > > > Signed-off-by: Robby Cai <r63905@freescale.com> > > --- > > arch/arm/boot/dts/imx6qdl-gw52xx.dtsi | 6 +++--- > > arch/arm/boot/dts/imx6qdl-gw53xx.dtsi | 6 +++--- > > arch/arm/boot/dts/imx6qdl-gw54xx.dtsi | 6 +++--- > > arch/arm/boot/dts/imx6qdl-nitrogen6x.dtsi | 6 +++--- > > arch/arm/boot/dts/imx6qdl-sabreauto.dtsi | 6 +++--- > > arch/arm/boot/dts/imx6qdl-sabrelite.dtsi | 6 +++--- > > arch/arm/boot/dts/imx6qdl-sabresd.dtsi | 6 +++--- > > 7 files changed, 21 insertions(+), 21 deletions(-) > > > > diff --git a/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi b/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi > > index b5756c2..33484d8 100644 > > --- a/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi > > +++ b/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi > > @@ -29,9 +29,9 @@ > > > > backlight { > > compatible = "pwm-backlight"; > > - pwms = <&pwm4 0 5000000>; > > - brightness-levels = <0 4 8 16 32 64 128 255>; > > - default-brightness-level = <7>; > > + pwms = <&pwm4 0 50000>; > > + brightness-levels = <0 20 30 40 50 60 70 80 90 100>; > > + default-brightness-level = <9>; I notice that the intervals are changed from exponential to linear. Is this really wanted here? I expect that the new settings result in huge steps in perceived brightness at low levels and a nearly imperceptible change at the last step. regards Philipp -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> -----Original Message----- > From: Philipp Zabel [mailto:p.zabel@pengutronix.de] > Sent: Thursday, January 22, 2015 11:38 PM > To: Shawn Guo > Cc: Cai Robby-R63905; linux-pwm@vger.kernel.org; Eric Nelson; Tim Harvey; > jg1.han@samsung.com; Troy Kisky; thierry.reding@gmail.com; > kernel@pengutronix.de; lee.jones@linaro.org; linux-arm- > kernel@lists.infradead.org > Subject: Re: [PATCH] ARM: dts: imx6qdl: Adjust the brightness setting for > LVDS panel > > Am Dienstag, den 20.01.2015, 19:38 +0800 schrieb Shawn Guo: > > Add LAKML and a few interested people. > > > > Shawn > > > > On Tue, Jan 20, 2015 at 06:22:35PM +0800, Robby Cai wrote: > > > Hannstar XGA panel is used by default on i.MX6QDL Sabre Auto/Lite/SD > > > or derived board. > > > > > > According to its data sheet [1], > > > a) the dimming duty cycle is 20% - 100%. > > > This patch changes the brightness-level from 20 to 100 with step 10 > > > to make it straight-forward. > > > b) the typical dimming frequency is 20KHz. > > > The previous setting is 200Hz. This patch corrects it. > > > > > > [1] > > > http://boundarydevices.com/wp-content/uploads/2013/06/HSD100PXN1-A00 > > > -C11-1.0.pdf > > > > > > Signed-off-by: Robby Cai <r63905@freescale.com> > > > --- > > > arch/arm/boot/dts/imx6qdl-gw52xx.dtsi | 6 +++--- > > > arch/arm/boot/dts/imx6qdl-gw53xx.dtsi | 6 +++--- > > > arch/arm/boot/dts/imx6qdl-gw54xx.dtsi | 6 +++--- > > > arch/arm/boot/dts/imx6qdl-nitrogen6x.dtsi | 6 +++--- > > > arch/arm/boot/dts/imx6qdl-sabreauto.dtsi | 6 +++--- > > > arch/arm/boot/dts/imx6qdl-sabrelite.dtsi | 6 +++--- > > > arch/arm/boot/dts/imx6qdl-sabresd.dtsi | 6 +++--- > > > 7 files changed, 21 insertions(+), 21 deletions(-) > > > > > > diff --git a/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi > > > b/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi > > > index b5756c2..33484d8 100644 > > > --- a/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi > > > +++ b/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi > > > @@ -29,9 +29,9 @@ > > > > > > backlight { > > > compatible = "pwm-backlight"; > > > - pwms = <&pwm4 0 5000000>; > > > - brightness-levels = <0 4 8 16 32 64 128 255>; > > > - default-brightness-level = <7>; > > > + pwms = <&pwm4 0 50000>; > > > + brightness-levels = <0 20 30 40 50 60 70 80 90 100>; > > > + default-brightness-level = <9>; > > I notice that the intervals are changed from exponential to linear. > Is this really wanted here? > I expect that the new settings result in huge steps in perceived > brightness at low levels and a nearly imperceptible change at the last > step. > > regards > Philipp No particular reason here. I understand your concern but seems there's no obvious rule. How about add some interpolation, such as <0 52 64 96 128 160 192 224 255> or even more, <0 52 64 80 96 112 128 144 160 176 192 208 224 240 255> Regards, Robby
Am Montag, den 26.01.2015, 14:44 +0000 schrieb Robby.Cai@freescale.com: > > I notice that the intervals are changed from exponential to linear. > > Is this really wanted here? > > I expect that the new settings result in huge steps in perceived > > brightness at low levels and a nearly imperceptible change at the last > > step. > > > > regards > > Philipp > > > No particular reason here. I understand your concern but seems there's no obvious rule. > How about add some interpolation, such as <0 52 64 96 128 160 192 224 255> > or even more, <0 52 64 80 96 112 128 144 160 176 192 208 224 240 255> I just wanted to point out the possible issue. Maybe somebody with the actual panel could sit down and experiment and come up with some visually pleasing steps. regards Philipp -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" 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/imx6qdl-gw52xx.dtsi b/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi index b5756c2..33484d8 100644 --- a/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi +++ b/arch/arm/boot/dts/imx6qdl-gw52xx.dtsi @@ -29,9 +29,9 @@ backlight { compatible = "pwm-backlight"; - pwms = <&pwm4 0 5000000>; - brightness-levels = <0 4 8 16 32 64 128 255>; - default-brightness-level = <7>; + pwms = <&pwm4 0 50000>; + brightness-levels = <0 20 30 40 50 60 70 80 90 100>; + default-brightness-level = <9>; }; leds { diff --git a/arch/arm/boot/dts/imx6qdl-gw53xx.dtsi b/arch/arm/boot/dts/imx6qdl-gw53xx.dtsi index 86f03c1..0d01751 100644 --- a/arch/arm/boot/dts/imx6qdl-gw53xx.dtsi +++ b/arch/arm/boot/dts/imx6qdl-gw53xx.dtsi @@ -30,9 +30,9 @@ backlight { compatible = "pwm-backlight"; - pwms = <&pwm4 0 5000000>; - brightness-levels = <0 4 8 16 32 64 128 255>; - default-brightness-level = <7>; + pwms = <&pwm4 0 50000>; + brightness-levels = <0 20 30 40 50 60 70 80 90 100>; + default-brightness-level = <9>; }; leds { diff --git a/arch/arm/boot/dts/imx6qdl-gw54xx.dtsi b/arch/arm/boot/dts/imx6qdl-gw54xx.dtsi index 4a8d97f..8973bf2 100644 --- a/arch/arm/boot/dts/imx6qdl-gw54xx.dtsi +++ b/arch/arm/boot/dts/imx6qdl-gw54xx.dtsi @@ -30,9 +30,9 @@ backlight { compatible = "pwm-backlight"; - pwms = <&pwm4 0 5000000>; - brightness-levels = <0 4 8 16 32 64 128 255>; - default-brightness-level = <7>; + pwms = <&pwm4 0 50000>; + brightness-levels = <0 20 30 40 50 60 70 80 90 100>; + default-brightness-level = <9>; }; leds { diff --git a/arch/arm/boot/dts/imx6qdl-nitrogen6x.dtsi b/arch/arm/boot/dts/imx6qdl-nitrogen6x.dtsi index 0821812..5453cf0 100644 --- a/arch/arm/boot/dts/imx6qdl-nitrogen6x.dtsi +++ b/arch/arm/boot/dts/imx6qdl-nitrogen6x.dtsi @@ -124,9 +124,9 @@ backlight_lvds { compatible = "pwm-backlight"; - pwms = <&pwm4 0 5000000>; - brightness-levels = <0 4 8 16 32 64 128 255>; - default-brightness-level = <7>; + pwms = <&pwm4 0 50000>; + brightness-levels = <0 20 30 40 50 60 70 80 90 100>; + default-brightness-level = <9>; power-supply = <®_3p3v>; status = "okay"; }; diff --git a/arch/arm/boot/dts/imx6qdl-sabreauto.dtsi b/arch/arm/boot/dts/imx6qdl-sabreauto.dtsi index 009abd6..2bfcf5a 100644 --- a/arch/arm/boot/dts/imx6qdl-sabreauto.dtsi +++ b/arch/arm/boot/dts/imx6qdl-sabreauto.dtsi @@ -38,9 +38,9 @@ backlight { compatible = "pwm-backlight"; - pwms = <&pwm3 0 5000000>; - brightness-levels = <0 4 8 16 32 64 128 255>; - default-brightness-level = <7>; + pwms = <&pwm3 0 50000>; + brightness-levels = <0 20 30 40 50 60 70 80 90 100>; + default-brightness-level = <9>; status = "okay"; }; }; diff --git a/arch/arm/boot/dts/imx6qdl-sabrelite.dtsi b/arch/arm/boot/dts/imx6qdl-sabrelite.dtsi index 0b28a9d..d1409c0 100644 --- a/arch/arm/boot/dts/imx6qdl-sabrelite.dtsi +++ b/arch/arm/boot/dts/imx6qdl-sabrelite.dtsi @@ -123,9 +123,9 @@ backlight_lvds { compatible = "pwm-backlight"; - pwms = <&pwm4 0 5000000>; - brightness-levels = <0 4 8 16 32 64 128 255>; - default-brightness-level = <7>; + pwms = <&pwm4 0 50000>; + brightness-levels = <0 20 30 40 50 60 70 80 90 100>; + default-brightness-level = <9>; power-supply = <®_3p3v>; status = "okay"; }; diff --git a/arch/arm/boot/dts/imx6qdl-sabresd.dtsi b/arch/arm/boot/dts/imx6qdl-sabresd.dtsi index f1cd214..3efc363 100644 --- a/arch/arm/boot/dts/imx6qdl-sabresd.dtsi +++ b/arch/arm/boot/dts/imx6qdl-sabresd.dtsi @@ -115,9 +115,9 @@ backlight { compatible = "pwm-backlight"; - pwms = <&pwm1 0 5000000>; - brightness-levels = <0 4 8 16 32 64 128 255>; - default-brightness-level = <7>; + pwms = <&pwm1 0 50000>; + brightness-levels = <0 20 30 40 50 60 70 80 90 100>; + default-brightness-level = <9>; status = "okay"; };
Hannstar XGA panel is used by default on i.MX6QDL Sabre Auto/Lite/SD or derived board. According to its data sheet [1], a) the dimming duty cycle is 20% - 100%. This patch changes the brightness-level from 20 to 100 with step 10 to make it straight-forward. b) the typical dimming frequency is 20KHz. The previous setting is 200Hz. This patch corrects it. [1] http://boundarydevices.com/wp-content/uploads/2013/06/HSD100PXN1-A00-C11-1.0.pdf Signed-off-by: Robby Cai <r63905@freescale.com> --- arch/arm/boot/dts/imx6qdl-gw52xx.dtsi | 6 +++--- arch/arm/boot/dts/imx6qdl-gw53xx.dtsi | 6 +++--- arch/arm/boot/dts/imx6qdl-gw54xx.dtsi | 6 +++--- arch/arm/boot/dts/imx6qdl-nitrogen6x.dtsi | 6 +++--- arch/arm/boot/dts/imx6qdl-sabreauto.dtsi | 6 +++--- arch/arm/boot/dts/imx6qdl-sabrelite.dtsi | 6 +++--- arch/arm/boot/dts/imx6qdl-sabresd.dtsi | 6 +++--- 7 files changed, 21 insertions(+), 21 deletions(-)