Input: pwm-vibra - add support for enable GPIO

Some pwm vibrators have a dedicated enable GPIO that needs to be set
high so that the vibrator works. Add support for that optionally.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Reviewed-by: Sebastian Reichel <sre@kernel.org>
Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org>
Link: https://lore.kernel.org/r/20230427-hammerhead-vibra-v1-3-e87eeb94da51@z3ntu.xyz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: z3ntu

drivers/input/misc/pwm-vibra.c

@@ -11,6 +11,7 @@
  *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
  */
 
+#include <linux/gpio/consumer.h>
 #include <linux/input.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -23,6 +24,7 @@
 
 struct pwm_vibrator {
 	struct input_dev *input;
+	struct gpio_desc *enable_gpio;
 	struct pwm_device *pwm;
 	struct pwm_device *pwm_dir;
 	struct regulator *vcc;
@@ -48,6 +50,8 @@ static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
 		vibrator->vcc_on = true;
 	}
 
+	gpiod_set_value_cansleep(vibrator->enable_gpio, 1);
+
 	pwm_get_state(vibrator->pwm, &state);
 	pwm_set_relative_duty_cycle(&state, vibrator->level, 0xffff);
 	state.enabled = true;
@@ -80,6 +84,8 @@ static void pwm_vibrator_stop(struct pwm_vibrator *vibrator)
 		pwm_disable(vibrator->pwm_dir);
 	pwm_disable(vibrator->pwm);
 
+	gpiod_set_value_cansleep(vibrator->enable_gpio, 0);
+
 	if (vibrator->vcc_on) {
 		regulator_disable(vibrator->vcc);
 		vibrator->vcc_on = false;
@@ -142,6 +148,16 @@ static int pwm_vibrator_probe(struct platform_device *pdev)
 		return err;
 	}
 
+	vibrator->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
+							GPIOD_OUT_LOW);
+	err = PTR_ERR_OR_ZERO(vibrator->enable_gpio);
+	if (err) {
+		if (err != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Failed to request enable gpio: %d\n",
+				err);
+		return err;
+	}
+
 	vibrator->pwm = devm_pwm_get(&pdev->dev, "enable");
 	err = PTR_ERR_OR_ZERO(vibrator->pwm);
 	if (err) {