[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 <meg...@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

[Dmitry Torokhov]

Hi Ondrej,

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

[Ondřej Jirman]

Hello Dmitry,

thanks for looking into the patch. :)

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

regards,
o.