diff mbox

arm64: dts: allwinner: a64: bananapi-m64: Add LED device node

Message ID 20171201162733.23156-1-wens@csie.org (mailing list archive)
State Mainlined, archived
Headers show

Commit Message

Chen-Yu Tsai Dec. 1, 2017, 4:27 p.m. UTC
The Bananapi-M64 has 3 LEDS in red, green, and blue. These are toggled
via GPIO lines, which drive transistors that control current across the
LEDS. The red LED is by default on, via an additional pull-up on the
control line. We consider this means that it is a power indicator.
So we set the "default-on" property for it.

The pingroups the GPIO lines belong to require external regulators be
enabled to be able to drive the GPIO high. These regulators also have
other purposes. However the pin controller does not have bindings for
regulators. Here we just set them to always-on.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
 .../boot/dts/allwinner/sun50i-a64-bananapi-m64.dts | 36 ++++++++++++++++++++++
 1 file changed, 36 insertions(+)

Comments

Jagan Teki Dec. 5, 2017, 6:15 a.m. UTC | #1
On Fri, Dec 1, 2017 at 9:57 PM, Chen-Yu Tsai <wens@csie.org> wrote:
> The Bananapi-M64 has 3 LEDS in red, green, and blue. These are toggled
> via GPIO lines, which drive transistors that control current across the
> LEDS. The red LED is by default on, via an additional pull-up on the
> control line. We consider this means that it is a power indicator.
> So we set the "default-on" property for it.
>
> The pingroups the GPIO lines belong to require external regulators be
> enabled to be able to drive the GPIO high. These regulators also have
> other purposes. However the pin controller does not have bindings for
> regulators. Here we just set them to always-on.
>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
>  .../boot/dts/allwinner/sun50i-a64-bananapi-m64.dts | 36 ++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts b/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts
> index 4a8d3f83a36e..a6975670cd1c 100644
> --- a/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts
> +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts
> @@ -60,6 +60,26 @@
>                 stdout-path = "serial0:115200n8";
>         };
>
> +       leds {
> +               compatible = "gpio-leds";
> +
> +               pwr-led {
> +                       label = "bananapi-m64:red:pwr";
> +                       gpios = <&pio 3 24 GPIO_ACTIVE_HIGH>; /* PD24 */
> +                       default-state = "on";
> +               };
> +
> +               green {
> +                       label = "bananapi-m64:green:user";
> +                       gpios = <&pio 4 14 GPIO_ACTIVE_HIGH>; /* PE14 */
> +               };
> +
> +               blue {
> +                       label = "bananapi-m64:blue:user";
> +                       gpios = <&pio 4 15 GPIO_ACTIVE_HIGH>; /* PE15 */
> +               };
> +       };
> +
>         wifi_pwrseq: wifi_pwrseq {
>                 compatible = "mmc-pwrseq-simple";
>                 reset-gpios = <&r_pio 0 2 GPIO_ACTIVE_LOW>; /* PL2 */
> @@ -153,6 +173,17 @@
>
>  #include "axp803.dtsi"
>
> +&reg_aldo1 {
> +       /*
> +        * This regulator also drives the PE pingroup GPIOs,
> +        * which also controls two LEDs.
> +        */
> +       regulator-always-on;
> +       regulator-min-microvolt = <2800000>;
> +       regulator-max-microvolt = <2800000>;

why 2.8v?

> +       regulator-name = "afvcc-csi";
> +};
> +
>  &reg_aldo2 {
>         regulator-always-on;
>         regulator-min-microvolt = <1800000>;
> @@ -168,6 +199,11 @@
>  };
>
>  &reg_dc1sw {
> +       /*
> +        * This regulator also indirectly drives the PD pingroup GPIOs,
> +        * which also controls the power LED.
> +        */
> +       regulator-always-on;

This make rgmii phy always on, does this make emac power-drop?
Chen-Yu Tsai Dec. 5, 2017, 6:19 a.m. UTC | #2
On Tue, Dec 5, 2017 at 2:15 PM, Jagan Teki <jagan@amarulasolutions.com> wrote:
> On Fri, Dec 1, 2017 at 9:57 PM, Chen-Yu Tsai <wens@csie.org> wrote:
>> The Bananapi-M64 has 3 LEDS in red, green, and blue. These are toggled
>> via GPIO lines, which drive transistors that control current across the
>> LEDS. The red LED is by default on, via an additional pull-up on the
>> control line. We consider this means that it is a power indicator.
>> So we set the "default-on" property for it.
>>
>> The pingroups the GPIO lines belong to require external regulators be
>> enabled to be able to drive the GPIO high. These regulators also have
>> other purposes. However the pin controller does not have bindings for
>> regulators. Here we just set them to always-on.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> ---
>>  .../boot/dts/allwinner/sun50i-a64-bananapi-m64.dts | 36 ++++++++++++++++++++++
>>  1 file changed, 36 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts b/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts
>> index 4a8d3f83a36e..a6975670cd1c 100644
>> --- a/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts
>> +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts
>> @@ -60,6 +60,26 @@
>>                 stdout-path = "serial0:115200n8";
>>         };
>>
>> +       leds {
>> +               compatible = "gpio-leds";
>> +
>> +               pwr-led {
>> +                       label = "bananapi-m64:red:pwr";
>> +                       gpios = <&pio 3 24 GPIO_ACTIVE_HIGH>; /* PD24 */
>> +                       default-state = "on";
>> +               };
>> +
>> +               green {
>> +                       label = "bananapi-m64:green:user";
>> +                       gpios = <&pio 4 14 GPIO_ACTIVE_HIGH>; /* PE14 */
>> +               };
>> +
>> +               blue {
>> +                       label = "bananapi-m64:blue:user";
>> +                       gpios = <&pio 4 15 GPIO_ACTIVE_HIGH>; /* PE15 */
>> +               };
>> +       };
>> +
>>         wifi_pwrseq: wifi_pwrseq {
>>                 compatible = "mmc-pwrseq-simple";
>>                 reset-gpios = <&r_pio 0 2 GPIO_ACTIVE_LOW>; /* PL2 */
>> @@ -153,6 +173,17 @@
>>
>>  #include "axp803.dtsi"
>>
>> +&reg_aldo1 {
>> +       /*
>> +        * This regulator also drives the PE pingroup GPIOs,
>> +        * which also controls two LEDs.
>> +        */
>> +       regulator-always-on;
>> +       regulator-min-microvolt = <2800000>;
>> +       regulator-max-microvolt = <2800000>;
>
> why 2.8v?

That is what is written on the schematics. Plus it seems camera
modules are meant to use 2.8v.

>
>> +       regulator-name = "afvcc-csi";
>> +};
>> +
>>  &reg_aldo2 {
>>         regulator-always-on;
>>         regulator-min-microvolt = <1800000>;
>> @@ -168,6 +199,11 @@
>>  };
>>
>>  &reg_dc1sw {
>> +       /*
>> +        * This regulator also indirectly drives the PD pingroup GPIOs,
>> +        * which also controls the power LED.
>> +        */
>> +       regulator-always-on;
>
> This make rgmii phy always on, does this make emac power-drop?

emac power-drop? Please elaborate.

ChenYu
Maxime Ripard Dec. 5, 2017, 10:05 a.m. UTC | #3
Hi,

On Sat, Dec 02, 2017 at 12:27:33AM +0800, Chen-Yu Tsai wrote:
> The Bananapi-M64 has 3 LEDS in red, green, and blue. These are toggled
> via GPIO lines, which drive transistors that control current across the
> LEDS. The red LED is by default on, via an additional pull-up on the
> control line. We consider this means that it is a power indicator.
> So we set the "default-on" property for it.
> 
> The pingroups the GPIO lines belong to require external regulators be
> enabled to be able to drive the GPIO high. These regulators also have
> other purposes. However the pin controller does not have bindings for
> regulators. Here we just set them to always-on.

I guess we should take the opportunity to do just that.

We have been deferring this for quite some time now, this is a perfect
occasion to do it once and for all :)

Maxime
Chen-Yu Tsai Dec. 5, 2017, 1 p.m. UTC | #4
On Tue, Dec 5, 2017 at 6:05 PM, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> Hi,
>
> On Sat, Dec 02, 2017 at 12:27:33AM +0800, Chen-Yu Tsai wrote:
>> The Bananapi-M64 has 3 LEDS in red, green, and blue. These are toggled
>> via GPIO lines, which drive transistors that control current across the
>> LEDS. The red LED is by default on, via an additional pull-up on the
>> control line. We consider this means that it is a power indicator.
>> So we set the "default-on" property for it.
>>
>> The pingroups the GPIO lines belong to require external regulators be
>> enabled to be able to drive the GPIO high. These regulators also have
>> other purposes. However the pin controller does not have bindings for
>> regulators. Here we just set them to always-on.
>
> I guess we should take the opportunity to do just that.
>
> We have been deferring this for quite some time now, this is a perfect
> occasion to do it once and for all :)

True. But right now I don't see an elegant solution. What is the purpose
of having the regulator tied to pinctrl / GPIO? You can't have the pinctrl
driver asking for the regulator at probe time, as it might not be available
or even have a cyclic dependency (because the PMIC is I2C driven, which
needs an I2C controller, which needs the pinctrl). If you defer fetching
the regulator to a later point, you might end up with an inconsistent state.
Again with the I2C driven regulator example, what happens if the regulator
core decides to turn the regulator off before the pinctrl side has a chance
to take a reference and enable it?


Regards
ChenYu
Maxime Ripard Dec. 8, 2017, 9:38 a.m. UTC | #5
On Tue, Dec 05, 2017 at 09:00:37PM +0800, Chen-Yu Tsai wrote:
> On Tue, Dec 5, 2017 at 6:05 PM, Maxime Ripard
> <maxime.ripard@free-electrons.com> wrote:
> > Hi,
> >
> > On Sat, Dec 02, 2017 at 12:27:33AM +0800, Chen-Yu Tsai wrote:
> >> The Bananapi-M64 has 3 LEDS in red, green, and blue. These are toggled
> >> via GPIO lines, which drive transistors that control current across the
> >> LEDS. The red LED is by default on, via an additional pull-up on the
> >> control line. We consider this means that it is a power indicator.
> >> So we set the "default-on" property for it.
> >>
> >> The pingroups the GPIO lines belong to require external regulators be
> >> enabled to be able to drive the GPIO high. These regulators also have
> >> other purposes. However the pin controller does not have bindings for
> >> regulators. Here we just set them to always-on.
> >
> > I guess we should take the opportunity to do just that.
> >
> > We have been deferring this for quite some time now, this is a perfect
> > occasion to do it once and for all :)
> 
> True. But right now I don't see an elegant solution. What is the purpose
> of having the regulator tied to pinctrl / GPIO? You can't have the pinctrl
> driver asking for the regulator at probe time, as it might not be available
> or even have a cyclic dependency (because the PMIC is I2C driven, which
> needs an I2C controller, which needs the pinctrl).

Ah, right, you definitely have a circular dependency.

> If you defer fetching the regulator to a later point, you might end
> up with an inconsistent state.  Again with the I2C driven regulator
> example, what happens if the regulator core decides to turn the
> regulator off before the pinctrl side has a chance to take a
> reference and enable it?

I guess you could implement something based on the an asynchronous
regulator_get. You call regulator_get_async (or whatever) in the
pinctrl probe, and get notified as soon as it is registered so that
you can act upon it.

Anyway, this is a bit too much to ask to enable 3 LEDs... I've applied
that patch.

Maxime
diff mbox

Patch

diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts b/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts
index 4a8d3f83a36e..a6975670cd1c 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-bananapi-m64.dts
@@ -60,6 +60,26 @@ 
 		stdout-path = "serial0:115200n8";
 	};
 
+	leds {
+		compatible = "gpio-leds";
+
+		pwr-led {
+			label = "bananapi-m64:red:pwr";
+			gpios = <&pio 3 24 GPIO_ACTIVE_HIGH>; /* PD24 */
+			default-state = "on";
+		};
+
+		green {
+			label = "bananapi-m64:green:user";
+			gpios = <&pio 4 14 GPIO_ACTIVE_HIGH>; /* PE14 */
+		};
+
+		blue {
+			label = "bananapi-m64:blue:user";
+			gpios = <&pio 4 15 GPIO_ACTIVE_HIGH>; /* PE15 */
+		};
+	};
+
 	wifi_pwrseq: wifi_pwrseq {
 		compatible = "mmc-pwrseq-simple";
 		reset-gpios = <&r_pio 0 2 GPIO_ACTIVE_LOW>; /* PL2 */
@@ -153,6 +173,17 @@ 
 
 #include "axp803.dtsi"
 
+&reg_aldo1 {
+	/*
+	 * This regulator also drives the PE pingroup GPIOs,
+	 * which also controls two LEDs.
+	 */
+	regulator-always-on;
+	regulator-min-microvolt = <2800000>;
+	regulator-max-microvolt = <2800000>;
+	regulator-name = "afvcc-csi";
+};
+
 &reg_aldo2 {
 	regulator-always-on;
 	regulator-min-microvolt = <1800000>;
@@ -168,6 +199,11 @@ 
 };
 
 &reg_dc1sw {
+	/*
+	 * This regulator also indirectly drives the PD pingroup GPIOs,
+	 * which also controls the power LED.
+	 */
+	regulator-always-on;
 	regulator-name = "vcc-phy";
 };