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

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Date:   Tue, 14 Jul 2020 12:23:01 +0200
From:   Ondrej Jirman <megous@...ous.com>
To:     linux-sunxi@...glegroups.com,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Maxime Ripard <mripard@...nel.org>,
        Chen-Yu Tsai <wens@...e.org>
Cc:     Ondrej Jirman <megous@...ous.com>, Luca Weiss <luca@...tu.xyz>,
        Tomas Novotny <tomas@...otny.cz>, linux-input@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Subject: [PATCH v4 2/4] input: gpio-vibra: Allow to use vcc-supply alone to control the vibrator

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@...ous.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