[PATCH 0/4] Add support for vibrator motor for TBS A711 Tablet

[PATCH 0/4] Add support for vibrator motor for TBS A711 Tablet

[Ondrej Jirman]

The tablet has a vibrator. Expose it via input subsystem (EV_FF).

Please take a look.

thank you and regards,
  Ondrej Jirman

Ondrej Jirman (4):
  dt-bindings: input: gpio-vibrator: Don't require enable-gpios
  input: gpio-vibra: Allow to use vcc-supply alone to control the
    vibrator
  ARM: dts: sun8i-a83t-tbs-a711: Add support for the vibrator motor
  ARM: dts: sun8i-a83t-tbs-a711: Increase voltage on the vibrator

 .../devicetree/bindings/input/gpio-vibrator.yaml         | 1 -
 arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts                | 9 +++++++--
 drivers/input/misc/gpio-vibra.c                          | 3 ++-
 3 files changed, 9 insertions(+), 4 deletions(-)

-- 
2.25.1

[PATCH 1/4] dt-bindings: input: gpio-vibrator: Don't require enable-gpios

[Ondrej Jirman]

It is possible to turn the motor on/off just by enabling/disabling
the vcc-supply.

Signed-off-by: Ondrej Jirman <megous@megous.com>
---
 Documentation/devicetree/bindings/input/gpio-vibrator.yaml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/input/gpio-vibrator.yaml b/Documentation/devicetree/bindings/input/gpio-vibrator.yaml
index b98bf9363c8ff..f8f4093a0a454 100644
--- a/Documentation/devicetree/bindings/input/gpio-vibrator.yaml
+++ b/Documentation/devicetree/bindings/input/gpio-vibrator.yaml
@@ -24,7 +24,6 @@ properties:
 
 required:
   - compatible
-  - enable-gpios
 
 examples:
   - |
-- 
2.25.1

Re: [PATCH 1/4] dt-bindings: input: gpio-vibrator: Don't require enable-gpios

[Rob Herring]

On Sun, 23 Feb 2020 00:14:25 +0100, Ondrej Jirman wrote:
> It is possible to turn the motor on/off just by enabling/disabling
> the vcc-supply.
> 
> Signed-off-by: Ondrej Jirman <megous@megous.com>
> ---
>  Documentation/devicetree/bindings/input/gpio-vibrator.yaml | 1 -
>  1 file changed, 1 deletion(-)
> 

Acked-by: Rob Herring <robh@kernel.org>

[PATCH 2/4] input: gpio-vibra: Allow to use vcc-supply alone to control the vibrator

[Ondrej Jirman]

Make enable-gpio optional to allow using this driver with
boards that have vibrator connected to a power supply without
intermediate gpio based enable circuitry.

Signed-off-by: Ondrej Jirman <megous@megous.com>
---
 drivers/input/misc/gpio-vibra.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/input/misc/gpio-vibra.c b/drivers/input/misc/gpio-vibra.c
index f79f75595dd73..f11877f04b43c 100644
--- a/drivers/input/misc/gpio-vibra.c
+++ b/drivers/input/misc/gpio-vibra.c
@@ -121,7 +121,8 @@ static int gpio_vibrator_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	vibrator->gpio = devm_gpiod_get(&pdev->dev, "enable", GPIOD_OUT_LOW);
+	vibrator->gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
+						 GPIOD_OUT_LOW);
 	err = PTR_ERR_OR_ZERO(vibrator->gpio);
 	if (err) {
 		if (err != -EPROBE_DEFER)
-- 
2.25.1

[PATCH 3/4] ARM: dts: sun8i-a83t-tbs-a711: Add support for the vibrator motor

[Ondrej Jirman]

The board has a vibrator mottor. Hook it to the input subsystem.

Signed-off-by: Ondrej Jirman <megous@megous.com>
---
 arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
index 2fd31a0a0b344..a22920275e99b 100644
--- a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
+++ b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
@@ -99,6 +99,11 @@ panel_input: endpoint {
 		};
 	};
 
+	vibrator {
+		compatible = "gpio-vibrator";
+		vcc-supply = <&reg_ldo_io1>;
+	};
+
 	reg_gps: reg-gps {
 		compatible = "regulator-fixed";
 		regulator-name = "gps";
-- 
2.25.1

Re: [PATCH 3/4] ARM: dts: sun8i-a83t-tbs-a711: Add support for the vibrator motor

[Maxime Ripard]

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Hi,

On Sun, Feb 23, 2020 at 12:14:27AM +0100, Ondrej Jirman wrote:
> The board has a vibrator mottor. Hook it to the input subsystem.
>
> Signed-off-by: Ondrej Jirman <megous@megous.com>
> ---
>  arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
> index 2fd31a0a0b344..a22920275e99b 100644
> --- a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
> +++ b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
> @@ -99,6 +99,11 @@ panel_input: endpoint {
>  		};
>  	};
>
> +	vibrator {
> +		compatible = "gpio-vibrator";
> +		vcc-supply = <&reg_ldo_io1>;
> +	};
> +

LDO IO1 can also be muxed in as a GPIO iirc, why did you choose the
regulator instead?

Maxime

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Re: [PATCH 3/4] ARM: dts: sun8i-a83t-tbs-a711: Add support for the vibrator motor

[Ondřej Jirman]

Hello,

On Mon, Feb 24, 2020 at 10:10:59AM +0100, Maxime Ripard wrote:
> Hi,
> 
> On Sun, Feb 23, 2020 at 12:14:27AM +0100, Ondrej Jirman wrote:
> > The board has a vibrator mottor. Hook it to the input subsystem.
> >
> > Signed-off-by: Ondrej Jirman <megous@megous.com>
> > ---
> >  arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
> > index 2fd31a0a0b344..a22920275e99b 100644
> > --- a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
> > +++ b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
> > @@ -99,6 +99,11 @@ panel_input: endpoint {
> >  		};
> >  	};
> >
> > +	vibrator {
> > +		compatible = "gpio-vibrator";
> > +		vcc-supply = <&reg_ldo_io1>;
> > +	};
> > +
> 
> LDO IO1 can also be muxed in as a GPIO iirc, why did you choose the
> regulator instead?

According to the specification, LDO needs to be enabled (value 0b11)
to achieve the specified max driving current of 150mA:

  https://megous.com/dl/tmp/92b7d9d94820c3ba.png

Otherwise the chip is probably just using the regular CMOS logic output
(typically limited to around 20-35mA, but not specified in this datasheet),
which would be probably overdriven, if we try to drive the motor with it.

And since we're driving a motor directly, the more the better.

thank you and regards,
	o.

> Maxime

Re: [PATCH 3/4] ARM: dts: sun8i-a83t-tbs-a711: Add support for the vibrator motor

[Maxime Ripard]

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On Mon, Feb 24, 2020 at 03:14:37PM +0100, Ondřej Jirman wrote:
> Hello,
>
> On Mon, Feb 24, 2020 at 10:10:59AM +0100, Maxime Ripard wrote:
> > Hi,
> >
> > On Sun, Feb 23, 2020 at 12:14:27AM +0100, Ondrej Jirman wrote:
> > > The board has a vibrator mottor. Hook it to the input subsystem.
> > >
> > > Signed-off-by: Ondrej Jirman <megous@megous.com>
> > > ---
> > >  arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts | 5 +++++
> > >  1 file changed, 5 insertions(+)
> > >
> > > diff --git a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
> > > index 2fd31a0a0b344..a22920275e99b 100644
> > > --- a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
> > > +++ b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
> > > @@ -99,6 +99,11 @@ panel_input: endpoint {
> > >  		};
> > >  	};
> > >
> > > +	vibrator {
> > > +		compatible = "gpio-vibrator";
> > > +		vcc-supply = <&reg_ldo_io1>;
> > > +	};
> > > +
> >
> > LDO IO1 can also be muxed in as a GPIO iirc, why did you choose the
> > regulator instead?
>
> According to the specification, LDO needs to be enabled (value 0b11)
> to achieve the specified max driving current of 150mA:
>
>   https://megous.com/dl/tmp/92b7d9d94820c3ba.png
>
> Otherwise the chip is probably just using the regular CMOS logic output
> (typically limited to around 20-35mA, but not specified in this datasheet),
> which would be probably overdriven, if we try to drive the motor with it.
>
> And since we're driving a motor directly, the more the better.

Ok, that works for me then. This is typically the kind of things that
should be in your commit log though, since it's basically the
motivation for doing what you're doing in your patches.

Maxime

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[PATCH 4/4] ARM: dts: sun8i-a83t-tbs-a711: Increase voltage on the vibrator

[Ondrej Jirman]

Vibrator motor is weak at the current voltage. Increase the voltage.

Signed-off-by: Ondrej Jirman <megous@megous.com>
---
 arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
index a22920275e99b..314491cdafca2 100644
--- a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
+++ b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
@@ -434,8 +434,8 @@ &reg_ldo_io0 {
 };
 
 &reg_ldo_io1 {
-	regulator-min-microvolt = <3100000>;
-	regulator-max-microvolt = <3100000>;
+	regulator-min-microvolt = <3300000>;
+	regulator-max-microvolt = <3300000>;
 	regulator-name = "vcc-vb";
 	status = "okay";
 };
-- 
2.25.1