[PATCH v2 0/4] Add support for vibrator motor for TBS A711 Tablet

[PATCH v2 0/4] Add support for vibrator motor for TBS A711 Tablet

[Ondrej Jirman]

The tablet has a vibrator motor. This patch series exposes it via
input subsystem (EV_FF).

I'd like to ask input maintainers to take the patches 1 and 2.
Patches 3 and 4 should go via the sunxi tree.

The change to the vibrator driver is meant to enable toggling the
vibrator motor just via a power supply itself. There's not additional
gpio driven switch on this tablet between the power supply for the
motor and the motor.

Please take a look.

Changes in v2:
- Added DT ack tag
- Add more information to the commit log (re use of LDO for the power)


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(-)

-- 
2.26.2

[PATCH v2 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>
Acked-by: Rob Herring <robh@kernel.org>
---
 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 2384465eaa19..c700b640bd53 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
 
 additionalProperties: false
 
-- 
2.26.2

Re: [PATCH v2 1/4] dt-bindings: input: gpio-vibrator: Don't require enable-gpios

[Dmitry Torokhov]

On Wed, May 13, 2020 at 12:22:02AM +0200, 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>
> Acked-by: Rob Herring <robh@kernel.org>
> ---
>  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 2384465eaa19..c700b640bd53 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

Hmm we need at least one of the 2 (gpio and supply). Should we encode it
in the binding?

Also, in the dirver code, I guess we need to switch to have regulator
optional (so we are not given the dummy one) and bail if neither
regulator nor GPIO is found.

Thanks.

-- 
Dmitry

Re: [PATCH v2 1/4] dt-bindings: input: gpio-vibrator: Don't require enable-gpios

[Ondřej Jirman]

On Tue, May 12, 2020 at 03:52:12PM -0700, Dmitry Torokhov wrote:
> On Wed, May 13, 2020 at 12:22:02AM +0200, 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>
> > Acked-by: Rob Herring <robh@kernel.org>
> > ---
> >  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 2384465eaa19..c700b640bd53 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
> 
> Hmm we need at least one of the 2 (gpio and supply). Should we encode it
> in the binding?

Not sure how to encode either one or the other property being required, but
not both at once.

Maybe I can add a supply-vibrator compatible to the driver and binding and
make requirements dependent on the compatible?

> Also, in the dirver code, I guess we need to switch to have regulator
> optional (so we are not given the dummy one) and bail if neither
> regulator nor GPIO is found.

Though nothing bad will happen in the driver if binding will lack both
of these. The driver will just not control any HW, so at least it's
failsafe as is.

regards,
	o.

> Thanks.
> 
> -- 
> Dmitry

Re: [PATCH v2 1/4] dt-bindings: input: gpio-vibrator: Don't require enable-gpios

[Dmitry Torokhov]

On Wed, May 13, 2020 at 01:05:57AM +0200, Ondřej Jirman wrote:
> On Tue, May 12, 2020 at 03:52:12PM -0700, Dmitry Torokhov wrote:
> > On Wed, May 13, 2020 at 12:22:02AM +0200, 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>
> > > Acked-by: Rob Herring <robh@kernel.org>
> > > ---
> > >  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 2384465eaa19..c700b640bd53 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
> > 
> > Hmm we need at least one of the 2 (gpio and supply). Should we encode it
> > in the binding?
> 
> Not sure how to encode either one or the other property being required, but
> not both at once.
> 
> Maybe I can add a supply-vibrator compatible to the driver and binding and
> make requirements dependent on the compatible?

Rob is our bindings overlord... I'll defer to him here.

Thanks.

-- 
Dmitry

[PATCH v2 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 f79f75595dd7..f11877f04b43 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)
-- 
2.26.2

[PATCH v2 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.

According to the PMIC specification, LDO needs to be enabled (value 0b11)
to achieve the specified max driving current of 150mA. We can't drive
the motor with just GPIO mode.

In GPIO mode the chip is probably just using the regular CMOS logic
output circuitry (typically limited to around 20-35mA, but not specified
in this datasheet).

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 bfc9bb277a49..a278a1e33930 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";
-- 
2.26.2

[PATCH v2 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 a278a1e33930..1e086e979348 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";
 };
-- 
2.26.2