[PATCH 0/4] ARM: dts: sun8i: Add pwm-backlight device for A23/A33 Q8 format tablets

[PATCH 0/4] ARM: dts: sun8i: Add pwm-backlight device for A23/A33 Q8 format tablets

[Chen-Yu Tsai]

Hi Maxime,

This series adds support for the PWM controlled backlight on the
A23/A33 Q8 tablets. The A23/A33 SoCs have the same PWM controller
as the A20, and the tablets use it to dim the LCD backlight.

The patches are pretty self-explaining.

Hans, could you test this on your TZX 723Q4? It's FEX file uses
a lower PWM frequency.


Regards
ChenYu


Chen-Yu Tsai (4):
  ARM: dts: sun8i: Add PWM controller node for A23/A33
  ARM: dts: sun8i: Add PWM channel 0 pinmux setting for A23/A33
  ARM: dts: sun8i: Enable PWM controller on A23/A33 Q8 format tablets
  ARM: dts: sun8i: Add pwm-backlight device for A23/A33 Q8 format
    tablets

 arch/arm/boot/dts/sun8i-a23-a33.dtsi   | 15 +++++++++++++++
 arch/arm/boot/dts/sun8i-q8-common.dtsi | 26 ++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

-- 
2.5.1

[PATCH 1/4] ARM: dts: sun8i: Add PWM controller node for A23/A33

[Chen-Yu Tsai]

A23/A33 have a PWM controller that is compatible to the one on the A20.
Add a device node for it.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 arch/arm/boot/dts/sun8i-a23-a33.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm/boot/dts/sun8i-a23-a33.dtsi b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
index 27a925ec17d2..e7054304018a 100644
--- a/arch/arm/boot/dts/sun8i-a23-a33.dtsi
+++ b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
@@ -466,6 +466,14 @@
 			interrupts = <GIC_SPI 25 IRQ_TYPE_LEVEL_HIGH>;
 		};
 
+		pwm: pwm at 01c21400 {
+			compatible = "allwinner,sun7i-a20-pwm";
+			reg = <0x01c21400 0xc>;
+			clocks = <&osc24M>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+
 		lradc: lradc at 01c22800 {
 			compatible = "allwinner,sun4i-a10-lradc-keys";
 			reg = <0x01c22800 0x100>;
-- 
2.5.1

[linux-sunxi] [PATCH 1/4] ARM: dts: sun8i: Add PWM controller node for A23/A33

[Hans de Goede]

Hi,

Good stuff, thanks for working on this.

On 09/18/2015 03:35 AM, Chen-Yu Tsai wrote:
> A23/A33 have a PWM controller that is compatible to the one on the A20.
> Add a device node for it.
>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>

Looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans


> ---
>   arch/arm/boot/dts/sun8i-a23-a33.dtsi | 8 ++++++++
>   1 file changed, 8 insertions(+)
>
> diff --git a/arch/arm/boot/dts/sun8i-a23-a33.dtsi b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
> index 27a925ec17d2..e7054304018a 100644
> --- a/arch/arm/boot/dts/sun8i-a23-a33.dtsi
> +++ b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
> @@ -466,6 +466,14 @@
>   			interrupts = <GIC_SPI 25 IRQ_TYPE_LEVEL_HIGH>;
>   		};
>
> +		pwm: pwm at 01c21400 {
> +			compatible = "allwinner,sun7i-a20-pwm";
> +			reg = <0x01c21400 0xc>;
> +			clocks = <&osc24M>;
> +			#pwm-cells = <3>;
> +			status = "disabled";
> +		};
> +
>   		lradc: lradc at 01c22800 {
>   			compatible = "allwinner,sun4i-a10-lradc-keys";
>   			reg = <0x01c22800 0x100>;
>

[PATCH 1/4] ARM: dts: sun8i: Add PWM controller node for A23/A33

[Maxime Ripard]

On Fri, Sep 18, 2015 at 03:35:36PM +0800, Chen-Yu Tsai wrote:
> A23/A33 have a PWM controller that is compatible to the one on the A20.
> Add a device node for it.
> 
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>

Applied, thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH 2/4] ARM: dts: sun8i: Add PWM channel 0 pinmux setting for A23/A33

[Chen-Yu Tsai]

The PWM controller has 2 outputs, with one usable pin for each.

Add a pinmux setting for the first channel. This is often used
for backlight dimming on tablets.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 arch/arm/boot/dts/sun8i-a23-a33.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm/boot/dts/sun8i-a23-a33.dtsi b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
index e7054304018a..8f4db82084c5 100644
--- a/arch/arm/boot/dts/sun8i-a23-a33.dtsi
+++ b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
@@ -412,6 +412,13 @@
 				allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
 			};
 
+			pwm0_pins: pwm0 {
+				allwinner,pins = "PH0";
+				allwinner,function = "pwm0";
+				allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+				allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+			};
+
 			i2c0_pins_a: i2c0 at 0 {
 				allwinner,pins = "PH2", "PH3";
 				allwinner,function = "i2c0";
-- 
2.5.1

[linux-sunxi] [PATCH 2/4] ARM: dts: sun8i: Add PWM channel 0 pinmux setting for A23/A33

[Hans de Goede]

Hi,

On 09/18/2015 03:35 AM, Chen-Yu Tsai wrote:
> The PWM controller has 2 outputs, with one usable pin for each.
>
> Add a pinmux setting for the first channel. This is often used
> for backlight dimming on tablets.
>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
>   arch/arm/boot/dts/sun8i-a23-a33.dtsi | 7 +++++++
>   1 file changed, 7 insertions(+)
>
> diff --git a/arch/arm/boot/dts/sun8i-a23-a33.dtsi b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
> index e7054304018a..8f4db82084c5 100644
> --- a/arch/arm/boot/dts/sun8i-a23-a33.dtsi
> +++ b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
> @@ -412,6 +412,13 @@
>   				allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
>   			};
>
> +			pwm0_pins: pwm0 {

This should be "pwm0_pins_a: pwm0 at 0" so as to be consistent with the a10 / a20 dtsi
files.

Regards,

Hans

> +				allwinner,pins = "PH0";
> +				allwinner,function = "pwm0";
> +				allwinner,drive = <SUN4I_PINCTRL_10_MA>;
> +				allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
> +			};
> +
>   			i2c0_pins_a: i2c0 at 0 {
>   				allwinner,pins = "PH2", "PH3";
>   				allwinner,function = "i2c0";
>

[linux-sunxi] [PATCH 2/4] ARM: dts: sun8i: Add PWM channel 0 pinmux setting for A23/A33

[Chen-Yu Tsai]

On Fri, Sep 18, 2015 at 11:30 PM, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
>
> On 09/18/2015 03:35 AM, Chen-Yu Tsai wrote:
>>
>> The PWM controller has 2 outputs, with one usable pin for each.
>>
>> Add a pinmux setting for the first channel. This is often used
>> for backlight dimming on tablets.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> ---
>>   arch/arm/boot/dts/sun8i-a23-a33.dtsi | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/sun8i-a23-a33.dtsi
>> b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
>> index e7054304018a..8f4db82084c5 100644
>> --- a/arch/arm/boot/dts/sun8i-a23-a33.dtsi
>> +++ b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
>> @@ -412,6 +412,13 @@
>>                                 allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
>>                         };
>>
>> +                       pwm0_pins: pwm0 {
>
>
> This should be "pwm0_pins_a: pwm0 at 0" so as to be consistent with the a10 /
> a20 dtsi
> files.

This is the only possible setting. I do not see why we need "_a" for the
label and "@0" for the name. IMHO they are used to avoid name clashes when
there are multiple possible pinmux settings.


Regards
ChenYu

> Regards,
>
> Hans
>
>
>> +                               allwinner,pins = "PH0";
>> +                               allwinner,function = "pwm0";
>> +                               allwinner,drive = <SUN4I_PINCTRL_10_MA>;
>> +                               allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
>> +                       };
>> +
>>                         i2c0_pins_a: i2c0 at 0 {
>>                                 allwinner,pins = "PH2", "PH3";
>>                                 allwinner,function = "i2c0";
>>
>

[linux-sunxi] [PATCH 2/4] ARM: dts: sun8i: Add PWM channel 0 pinmux setting for A23/A33

[Maxime Ripard]

On Sat, Sep 19, 2015 at 12:18:04AM +0800, Chen-Yu Tsai wrote:
> On Fri, Sep 18, 2015 at 11:30 PM, Hans de Goede <hdegoede@redhat.com> wrote:
> > Hi,
> >
> > On 09/18/2015 03:35 AM, Chen-Yu Tsai wrote:
> >>
> >> The PWM controller has 2 outputs, with one usable pin for each.
> >>
> >> Add a pinmux setting for the first channel. This is often used
> >> for backlight dimming on tablets.
> >>
> >> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> >> ---
> >>   arch/arm/boot/dts/sun8i-a23-a33.dtsi | 7 +++++++
> >>   1 file changed, 7 insertions(+)
> >>
> >> diff --git a/arch/arm/boot/dts/sun8i-a23-a33.dtsi
> >> b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
> >> index e7054304018a..8f4db82084c5 100644
> >> --- a/arch/arm/boot/dts/sun8i-a23-a33.dtsi
> >> +++ b/arch/arm/boot/dts/sun8i-a23-a33.dtsi
> >> @@ -412,6 +412,13 @@
> >>                                 allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
> >>                         };
> >>
> >> +                       pwm0_pins: pwm0 {
> >
> >
> > This should be "pwm0_pins_a: pwm0 at 0" so as to be consistent with the a10 /
> > a20 dtsi
> > files.
> 
> This is the only possible setting. I do not see why we need "_a" for the
> label and "@0" for the name. IMHO they are used to avoid name clashes when
> there are multiple possible pinmux settings.

Yep, sounds reasonable, I applied the patch.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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[PATCH 3/4] ARM: dts: sun8i: Enable PWM controller on A23/A33 Q8 format tablets

[Chen-Yu Tsai]

A23/A33 based Q8 format tablets use channel 0 of the PWM controller for
backlight dimming.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 arch/arm/boot/dts/sun8i-q8-common.dtsi | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/sun8i-q8-common.dtsi b/arch/arm/boot/dts/sun8i-q8-common.dtsi
index 6f8a8bb4e9bb..4c2d0b459d6f 100644
--- a/arch/arm/boot/dts/sun8i-q8-common.dtsi
+++ b/arch/arm/boot/dts/sun8i-q8-common.dtsi
@@ -70,6 +70,12 @@
 	};
 };
 
+&pwm {
+	pinctrl-names = "default";
+	pinctrl-0 = <&pwm0_pins>;
+	status = "okay";
+};
+
 &r_uart {
 	pinctrl-names = "default";
 	pinctrl-0 = <&r_uart_pins_a>;
-- 
2.5.1

[linux-sunxi] [PATCH 3/4] ARM: dts: sun8i: Enable PWM controller on A23/A33 Q8 format tablets

[Hans de Goede]

Hi,

On 09/18/2015 03:35 AM, Chen-Yu Tsai wrote:
> A23/A33 based Q8 format tablets use channel 0 of the PWM controller for
> backlight dimming.
>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
>   arch/arm/boot/dts/sun8i-q8-common.dtsi | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/arch/arm/boot/dts/sun8i-q8-common.dtsi b/arch/arm/boot/dts/sun8i-q8-common.dtsi
> index 6f8a8bb4e9bb..4c2d0b459d6f 100644
> --- a/arch/arm/boot/dts/sun8i-q8-common.dtsi
> +++ b/arch/arm/boot/dts/sun8i-q8-common.dtsi
> @@ -70,6 +70,12 @@
>   	};
>   };
>
> +&pwm {
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&pwm0_pins>;
> +	status = "okay";
> +};
> +
>   &r_uart {
>   	pinctrl-names = "default";
>   	pinctrl-0 = <&r_uart_pins_a>;
>

I've a feeling this should be in sunxi-q8-common.dtsi not sun8i-q8-common.dtsi, which requires adding a pwm
node to sun5i.dtsi I'll look into this.

Regards,

Hans

[linux-sunxi] [PATCH 3/4] ARM: dts: sun8i: Enable PWM controller on A23/A33 Q8 format tablets

[Chen-Yu Tsai]

On Fri, Sep 18, 2015 at 11:32 PM, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi,
>
> On 09/18/2015 03:35 AM, Chen-Yu Tsai wrote:
>>
>> A23/A33 based Q8 format tablets use channel 0 of the PWM controller for
>> backlight dimming.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> ---
>>   arch/arm/boot/dts/sun8i-q8-common.dtsi | 6 ++++++
>>   1 file changed, 6 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/sun8i-q8-common.dtsi
>> b/arch/arm/boot/dts/sun8i-q8-common.dtsi
>> index 6f8a8bb4e9bb..4c2d0b459d6f 100644
>> --- a/arch/arm/boot/dts/sun8i-q8-common.dtsi
>> +++ b/arch/arm/boot/dts/sun8i-q8-common.dtsi
>> @@ -70,6 +70,12 @@
>>         };
>>   };
>>
>> +&pwm {
>> +       pinctrl-names = "default";
>> +       pinctrl-0 = <&pwm0_pins>;
>> +       status = "okay";
>> +};
>> +
>>   &r_uart {
>>         pinctrl-names = "default";
>>         pinctrl-0 = <&r_uart_pins_a>;
>>
>
> I've a feeling this should be in sunxi-q8-common.dtsi not
> sun8i-q8-common.dtsi, which requires adding a pwm
> node to sun5i.dtsi I'll look into this.

It probably should. IIRC sun5i PWM has only one channel as opposed to
2 on A10/A20.


ChenYu

[linux-sunxi] [PATCH 3/4] ARM: dts: sun8i: Enable PWM controller on A23/A33 Q8 format tablets

[Hans de Goede]

Hi,

On 09/18/2015 12:25 PM, Chen-Yu Tsai wrote:
> On Fri, Sep 18, 2015 at 11:32 PM, Hans de Goede <hdegoede@redhat.com> wrote:
>> Hi,
>>
>> On 09/18/2015 03:35 AM, Chen-Yu Tsai wrote:
>>>
>>> A23/A33 based Q8 format tablets use channel 0 of the PWM controller for
>>> backlight dimming.
>>>
>>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>>> ---
>>>    arch/arm/boot/dts/sun8i-q8-common.dtsi | 6 ++++++
>>>    1 file changed, 6 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/sun8i-q8-common.dtsi
>>> b/arch/arm/boot/dts/sun8i-q8-common.dtsi
>>> index 6f8a8bb4e9bb..4c2d0b459d6f 100644
>>> --- a/arch/arm/boot/dts/sun8i-q8-common.dtsi
>>> +++ b/arch/arm/boot/dts/sun8i-q8-common.dtsi
>>> @@ -70,6 +70,12 @@
>>>          };
>>>    };
>>>
>>> +&pwm {
>>> +       pinctrl-names = "default";
>>> +       pinctrl-0 = <&pwm0_pins>;
>>> +       status = "okay";
>>> +};
>>> +
>>>    &r_uart {
>>>          pinctrl-names = "default";
>>>          pinctrl-0 = <&r_uart_pins_a>;
>>>
>>
>> I've a feeling this should be in sunxi-q8-common.dtsi not
>> sun8i-q8-common.dtsi, which requires adding a pwm
>> node to sun5i.dtsi I'll look into this.
>
> It probably should.

Which means the name of the pinctrl node should be the same
on both, hence my request to rename that. Anyways Maxime
has already merged that now, I'll workaround it and / or
do a followup patch.

> IIRC sun5i PWM has only one channel as opposed to
> 2 on A10/A20.

Nope sun5i has 2 channels, but the second channel is
only routed to the outside on A10s, not on A13.

Regards,

Hans

[PATCH 4/4] ARM: dts: sun8i: Add pwm-backlight device for A23/A33 Q8 format tablets

[Chen-Yu Tsai]

The LCD backlight on the A23/A33 Q8 format tablets is enabled
with a GPIO controlled regulator, and brightness controlled with
the SoC's PWM controller.

The backlight is powered from the AXP223 PMIC's DC1SW output,
which is not supported yet. A proper bootloader is required
to enable it.

The brightness levels are arbitrary. The FEX files do not have
such information. As such, actual brightness levels may differ
from device to device.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 arch/arm/boot/dts/sun8i-q8-common.dtsi | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/arm/boot/dts/sun8i-q8-common.dtsi b/arch/arm/boot/dts/sun8i-q8-common.dtsi
index 4c2d0b459d6f..8a56ff567911 100644
--- a/arch/arm/boot/dts/sun8i-q8-common.dtsi
+++ b/arch/arm/boot/dts/sun8i-q8-common.dtsi
@@ -41,11 +41,24 @@
  */
 #include "sunxi-q8-common.dtsi"
 
+#include <dt-bindings/pwm/pwm.h>
+
 / {
 	aliases {
 		serial0 = &r_uart;
 	};
 
+	backlight: backlight {
+		compatible = "pwm-backlight";
+		pinctrl-names = "default";
+		pinctrl-0 = <&bl_en_pin_q8>;
+		pwms = <&pwm 0 50000 PWM_POLARITY_INVERTED>;
+		brightness-levels = <0 10 20 30 40 50 60 70 80 90 100>;
+		default-brightness-level = <8>;
+		enable-gpios = <&pio 7 6 GPIO_ACTIVE_HIGH>; /* PH6 */
+		/* backlight is powered by AXP223 DC1SW */
+	};
+
 	chosen {
 		stdout-path = "serial0:115200n8";
 	};
@@ -62,6 +75,13 @@
 };
 
 &pio {
+	bl_en_pin_q8: bl_en_pin at 0 {
+		allwinner,pins = "PH6";
+		allwinner,function = "gpio_in";
+		allwinner,drive = <SUN4I_PINCTRL_10_MA>;
+		allwinner,pull = <SUN4I_PINCTRL_NO_PULL>;
+	};
+
 	mmc0_cd_pin_q8: mmc0_cd_pin at 0 {
 		allwinner,pins = "PB4";
 		allwinner,function = "gpio_in";
-- 
2.5.1