[PATCH v4 0/4] Add support for vibrator motor for TBS A711 Tablet

[PATCH v4 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 v4:
- Added DT reviewed-by tag
- Fixed motor typo

Changes in v3:
- Changed dt-binding to require at least one of enable/supply, dropped ack
- Changed driver to bail out if neither supply nor gpio is given

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   |  7 ++++++-
 arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts          |  9 +++++++--
 drivers/input/misc/gpio-vibra.c                    | 14 ++++++++++----
 3 files changed, 23 insertions(+), 7 deletions(-)

-- 
2.27.0

[PATCH v4 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. Change the binding to require either enable-gpios
or vcc-supply or both.

Signed-off-by: Ondrej Jirman <megous@megous.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/input/gpio-vibrator.yaml | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/input/gpio-vibrator.yaml b/Documentation/devicetree/bindings/input/gpio-vibrator.yaml
index 2384465eaa19..082ac06471db 100644
--- a/Documentation/devicetree/bindings/input/gpio-vibrator.yaml
+++ b/Documentation/devicetree/bindings/input/gpio-vibrator.yaml
@@ -24,7 +24,12 @@ properties:
 
 required:
   - compatible
-  - enable-gpios
+
+anyOf:
+  - required:
+    - enable-gpios
+  - required:
+    - vcc-supply
 
 additionalProperties: false
 
-- 
2.27.0

[PATCH v4 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.

Also avoid a case where neither regulator nor enable gpio is specified,
and bail out in probe in such a case.

Signed-off-by: Ondrej Jirman <megous@megous.com>
---
 drivers/input/misc/gpio-vibra.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/input/misc/gpio-vibra.c b/drivers/input/misc/gpio-vibra.c
index f79f75595dd7..b3bb7e61ed1d 100644
--- a/drivers/input/misc/gpio-vibra.c
+++ b/drivers/input/misc/gpio-vibra.c
@@ -39,7 +39,7 @@ static int gpio_vibrator_start(struct gpio_vibrator *vibrator)
 	struct device *pdev = vibrator->input->dev.parent;
 	int err;
 
-	if (!vibrator->vcc_on) {
+	if (vibrator->vcc && !vibrator->vcc_on) {
 		err = regulator_enable(vibrator->vcc);
 		if (err) {
 			dev_err(pdev, "failed to enable regulator: %d\n", err);
@@ -57,7 +57,7 @@ static void gpio_vibrator_stop(struct gpio_vibrator *vibrator)
 {
 	gpiod_set_value_cansleep(vibrator->gpio, 0);
 
-	if (vibrator->vcc_on) {
+	if (vibrator->vcc && vibrator->vcc_on) {
 		regulator_disable(vibrator->vcc);
 		vibrator->vcc_on = false;
 	}
@@ -112,7 +112,7 @@ static int gpio_vibrator_probe(struct platform_device *pdev)
 	if (!vibrator->input)
 		return -ENOMEM;
 
-	vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
+	vibrator->vcc = devm_regulator_get_optional(&pdev->dev, "vcc");
 	err = PTR_ERR_OR_ZERO(vibrator->vcc);
 	if (err) {
 		if (err != -EPROBE_DEFER)
@@ -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)
@@ -130,6 +131,11 @@ static int gpio_vibrator_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	if (!vibrator->vcc && !vibrator->gpio) {
+		dev_err(&pdev->dev, "Neither gpio nor regulator provided\n");
+		return -EINVAL;
+	}
+
 	INIT_WORK(&vibrator->play_work, gpio_vibrator_play_work);
 
 	vibrator->input->name = "gpio-vibrator";
-- 
2.27.0

Re: [PATCH v4 2/4] input: gpio-vibra: Allow to use vcc-supply alone to control the vibrator

[Dmitry Torokhov]

Hi Ondrej,

On Tue, Jul 14, 2020 at 12:23:01PM +0200, Ondrej Jirman wrote:
> 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.
> 
> Also avoid a case where neither regulator nor enable gpio is specified,
> and bail out in probe in such a case.
> 
> Signed-off-by: Ondrej Jirman <megous@megous.com>
> ---
>  drivers/input/misc/gpio-vibra.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/input/misc/gpio-vibra.c b/drivers/input/misc/gpio-vibra.c
> index f79f75595dd7..b3bb7e61ed1d 100644
> --- a/drivers/input/misc/gpio-vibra.c
> +++ b/drivers/input/misc/gpio-vibra.c
> @@ -39,7 +39,7 @@ static int gpio_vibrator_start(struct gpio_vibrator *vibrator)
>  	struct device *pdev = vibrator->input->dev.parent;
>  	int err;
>  
> -	if (!vibrator->vcc_on) {
> +	if (vibrator->vcc && !vibrator->vcc_on) {
>  		err = regulator_enable(vibrator->vcc);
>  		if (err) {
>  			dev_err(pdev, "failed to enable regulator: %d\n", err);
> @@ -57,7 +57,7 @@ static void gpio_vibrator_stop(struct gpio_vibrator *vibrator)
>  {
>  	gpiod_set_value_cansleep(vibrator->gpio, 0);
>  
> -	if (vibrator->vcc_on) {
> +	if (vibrator->vcc && vibrator->vcc_on) {
>  		regulator_disable(vibrator->vcc);
>  		vibrator->vcc_on = false;
>  	}
> @@ -112,7 +112,7 @@ static int gpio_vibrator_probe(struct platform_device *pdev)
>  	if (!vibrator->input)
>  		return -ENOMEM;
>  
> -	vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
> +	vibrator->vcc = devm_regulator_get_optional(&pdev->dev, "vcc");

I know it is very surprising, but regulator_get_optional does not return
NULL when regulator is not present, but rather ERR_PTR(-ENODEV). You
need to replace it with NULL in the branch below, or change conditions
to !IS_ERR(virbrator->vcc) (and still handle -ENODEV in the branch
below).

>  	err = PTR_ERR_OR_ZERO(vibrator->vcc);
>  	if (err) {
>  		if (err != -EPROBE_DEFER)
> @@ -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)
> @@ -130,6 +131,11 @@ static int gpio_vibrator_probe(struct platform_device *pdev)
>  		return err;
>  	}
>  
> +	if (!vibrator->vcc && !vibrator->gpio) {
> +		dev_err(&pdev->dev, "Neither gpio nor regulator provided\n");
> +		return -EINVAL;
> +	}
> +
>  	INIT_WORK(&vibrator->play_work, gpio_vibrator_play_work);
>  
>  	vibrator->input->name = "gpio-vibrator";
> -- 
> 2.27.0
> 

Thanks.

-- 
Dmitry

Re: [PATCH v4 2/4] input: gpio-vibra: Allow to use vcc-supply alone to control the vibrator

[Ondřej Jirman]

Hello Dmitry,

thanks for looking into the patch. :)

On Wed, Jul 29, 2020 at 11:19:39PM -0700, Dmitry Torokhov wrote:
> Hi Ondrej,
> 
> On Tue, Jul 14, 2020 at 12:23:01PM +0200, Ondrej Jirman wrote:
> > 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.
> > 
> > Also avoid a case where neither regulator nor enable gpio is specified,
> > and bail out in probe in such a case.
> > 
> > Signed-off-by: Ondrej Jirman <megous@megous.com>
> > ---
> >  drivers/input/misc/gpio-vibra.c | 14 ++++++++++----
> >  1 file changed, 10 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/input/misc/gpio-vibra.c b/drivers/input/misc/gpio-vibra.c
> > index f79f75595dd7..b3bb7e61ed1d 100644
> > --- a/drivers/input/misc/gpio-vibra.c
> > +++ b/drivers/input/misc/gpio-vibra.c
> > @@ -39,7 +39,7 @@ static int gpio_vibrator_start(struct gpio_vibrator *vibrator)
> >  	struct device *pdev = vibrator->input->dev.parent;
> >  	int err;
> >  
> > -	if (!vibrator->vcc_on) {
> > +	if (vibrator->vcc && !vibrator->vcc_on) {
> >  		err = regulator_enable(vibrator->vcc);
> >  		if (err) {
> >  			dev_err(pdev, "failed to enable regulator: %d\n", err);
> > @@ -57,7 +57,7 @@ static void gpio_vibrator_stop(struct gpio_vibrator *vibrator)
> >  {
> >  	gpiod_set_value_cansleep(vibrator->gpio, 0);
> >  
> > -	if (vibrator->vcc_on) {
> > +	if (vibrator->vcc && vibrator->vcc_on) {
> >  		regulator_disable(vibrator->vcc);
> >  		vibrator->vcc_on = false;
> >  	}
> > @@ -112,7 +112,7 @@ static int gpio_vibrator_probe(struct platform_device *pdev)
> >  	if (!vibrator->input)
> >  		return -ENOMEM;
> >  
> > -	vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
> > +	vibrator->vcc = devm_regulator_get_optional(&pdev->dev, "vcc");
> 
> I know it is very surprising, but regulator_get_optional does not return
> NULL when regulator is not present, but rather ERR_PTR(-ENODEV). You
> need to replace it with NULL in the branch below, or change conditions
> to !IS_ERR(virbrator->vcc) (and still handle -ENODEV in the branch
> below).

Oops, I'll fix that in the next revision.

regards,
	o.

> >  	err = PTR_ERR_OR_ZERO(vibrator->vcc);
> >  	if (err) {
> >  		if (err != -EPROBE_DEFER)
> > @@ -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)
> > @@ -130,6 +131,11 @@ static int gpio_vibrator_probe(struct platform_device *pdev)
> >  		return err;
> >  	}
> >  
> > +	if (!vibrator->vcc && !vibrator->gpio) {
> > +		dev_err(&pdev->dev, "Neither gpio nor regulator provided\n");
> > +		return -EINVAL;
> > +	}
> > +
> >  	INIT_WORK(&vibrator->play_work, gpio_vibrator_play_work);
> >  
> >  	vibrator->input->name = "gpio-vibrator";
> > -- 
> > 2.27.0
> > 
> 
> Thanks.
> 
> -- 
> Dmitry

[PATCH v4 3/4] ARM: dts: sun8i-a83t-tbs-a711: Add support for the vibrator motor

[Ondrej Jirman]

The board has a vibrator motor. 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";
-- 
2.27.0

[PATCH v4 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";
 };
-- 
2.27.0