1 files changed, 138 insertions, 84 deletions

diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
index a37f0c909aba..0e19e97d98ec 100644
--- a/drivers/input/misc/pwm-beeper.c
+++ b/drivers/input/misc/pwm-beeper.c
@@ -1,46 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
  *  PWM beeper driver
- *
- *  This program is free software; you can redistribute it and/or modify it
- *  under  the terms of the GNU General  Public License as published by the
- *  Free Software Foundation;  either version 2 of the License, or (at your
- *  option) any later version.
- *
- *  You should have received a copy of the GNU General Public License along
- *  with this program; if not, write to the Free Software Foundation, Inc.,
- *  675 Mass Ave, Cambridge, MA 02139, USA.
- *
  */
 
 #include <linux/input.h>
+#include <linux/regulator/consumer.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/property.h>
 #include <linux/pwm.h>
 #include <linux/slab.h>
+#include <linux/workqueue.h>
 
 struct pwm_beeper {
 	struct input_dev *input;
 	struct pwm_device *pwm;
+	struct regulator *amplifier;
+	struct work_struct work;
 	unsigned long period;
+	unsigned int bell_frequency;
+	bool suspended;
+	bool amplifier_on;
 };
 
 #define HZ_TO_NANOSECONDS(x) (1000000000UL/(x))
 
+static int pwm_beeper_on(struct pwm_beeper *beeper, unsigned long period)
+{
+	struct pwm_state state;
+	int error;
+
+	pwm_get_state(beeper->pwm, &state);
+
+	state.enabled = true;
+	state.period = period;
+	pwm_set_relative_duty_cycle(&state, 50, 100);
+
+	error = pwm_apply_might_sleep(beeper->pwm, &state);
+	if (error)
+		return error;
+
+	if (!beeper->amplifier_on) {
+		error = regulator_enable(beeper->amplifier);
+		if (error) {
+			pwm_disable(beeper->pwm);
+			return error;
+		}
+
+		beeper->amplifier_on = true;
+	}
+
+	return 0;
+}
+
+static void pwm_beeper_off(struct pwm_beeper *beeper)
+{
+	if (beeper->amplifier_on) {
+		regulator_disable(beeper->amplifier);
+		beeper->amplifier_on = false;
+	}
+
+	pwm_disable(beeper->pwm);
+}
+
+static void pwm_beeper_work(struct work_struct *work)
+{
+	struct pwm_beeper *beeper = container_of(work, struct pwm_beeper, work);
+	unsigned long period = READ_ONCE(beeper->period);
+
+	if (period)
+		pwm_beeper_on(beeper, period);
+	else
+		pwm_beeper_off(beeper);
+}
+
 static int pwm_beeper_event(struct input_dev *input,
 			    unsigned int type, unsigned int code, int value)
 {
-	int ret = 0;
 	struct pwm_beeper *beeper = input_get_drvdata(input);
-	unsigned long period;
 
 	if (type != EV_SND || value < 0)
 		return -EINVAL;
 
 	switch (code) {
 	case SND_BELL:
-		value = value ? 1000 : 0;
+		value = value ? beeper->bell_frequency : 0;
 		break;
 	case SND_TONE:
 		break;
@@ -48,52 +95,78 @@ static int pwm_beeper_event(struct input_dev *input,
 		return -EINVAL;
 	}
 
-	if (value == 0) {
-		pwm_config(beeper->pwm, 0, 0);
-		pwm_disable(beeper->pwm);
-	} else {
-		period = HZ_TO_NANOSECONDS(value);
-		ret = pwm_config(beeper->pwm, period / 2, period);
-		if (ret)
-			return ret;
-		ret = pwm_enable(beeper->pwm);
-		if (ret)
-			return ret;
-		beeper->period = period;
-	}
+	if (value == 0)
+		beeper->period = 0;
+	else
+		beeper->period = HZ_TO_NANOSECONDS(value);
+
+	if (!beeper->suspended)
+		schedule_work(&beeper->work);
 
 	return 0;
 }
 
+static void pwm_beeper_stop(struct pwm_beeper *beeper)
+{
+	cancel_work_sync(&beeper->work);
+	pwm_beeper_off(beeper);
+}
+
+static void pwm_beeper_close(struct input_dev *input)
+{
+	struct pwm_beeper *beeper = input_get_drvdata(input);
+
+	pwm_beeper_stop(beeper);
+}
+
 static int pwm_beeper_probe(struct platform_device *pdev)
 {
-	unsigned long pwm_id = (unsigned long)pdev->dev.platform_data;
+	struct device *dev = &pdev->dev;
 	struct pwm_beeper *beeper;
+	struct pwm_state state;
+	u32 bell_frequency;
 	int error;
 
-	beeper = kzalloc(sizeof(*beeper), GFP_KERNEL);
+	beeper = devm_kzalloc(dev, sizeof(*beeper), GFP_KERNEL);
 	if (!beeper)
 		return -ENOMEM;
 
-	beeper->pwm = pwm_get(&pdev->dev, NULL);
-	if (IS_ERR(beeper->pwm)) {
-		dev_dbg(&pdev->dev, "unable to request PWM, trying legacy API\n");
-		beeper->pwm = pwm_request(pwm_id, "pwm beeper");
+	beeper->pwm = devm_pwm_get(dev, NULL);
+	if (IS_ERR(beeper->pwm))
+		return dev_err_probe(dev, PTR_ERR(beeper->pwm), "Failed to request PWM device\n");
+
+	/* Sync up PWM state and ensure it is off. */
+	pwm_init_state(beeper->pwm, &state);
+	state.enabled = false;
+	error = pwm_apply_might_sleep(beeper->pwm, &state);
+	if (error) {
+		dev_err(dev, "failed to apply initial PWM state: %d\n",
+			error);
+		return error;
 	}
 
-	if (IS_ERR(beeper->pwm)) {
-		error = PTR_ERR(beeper->pwm);
-		dev_err(&pdev->dev, "Failed to request pwm device: %d\n", error);
-		goto err_free;
+	beeper->amplifier = devm_regulator_get(dev, "amp");
+	if (IS_ERR(beeper->amplifier))
+		return dev_err_probe(dev, PTR_ERR(beeper->amplifier),
+				     "Failed to get 'amp' regulator\n");
+
+	INIT_WORK(&beeper->work, pwm_beeper_work);
+
+	error = device_property_read_u32(dev, "beeper-hz", &bell_frequency);
+	if (error) {
+		bell_frequency = 1000;
+		dev_dbg(dev,
+			"failed to parse 'beeper-hz' property, using default: %uHz\n",
+			bell_frequency);
 	}
 
-	beeper->input = input_allocate_device();
+	beeper->bell_frequency = bell_frequency;
+
+	beeper->input = devm_input_allocate_device(dev);
 	if (!beeper->input) {
-		dev_err(&pdev->dev, "Failed to allocate input device\n");
-		error = -ENOMEM;
-		goto err_pwm_free;
+		dev_err(dev, "Failed to allocate input device\n");
+		return -ENOMEM;
 	}
-	beeper->input->dev.parent = &pdev->dev;
 
 	beeper->input->name = "pwm-beeper";
 	beeper->input->phys = "pwm/input0";
@@ -102,54 +175,39 @@ static int pwm_beeper_probe(struct platform_device *pdev)
 	beeper->input->id.product = 0x0001;
 	beeper->input->id.version = 0x0100;
 
-	beeper->input->evbit[0] = BIT(EV_SND);
-	beeper->input->sndbit[0] = BIT(SND_TONE) | BIT(SND_BELL);
+	input_set_capability(beeper->input, EV_SND, SND_TONE);
+	input_set_capability(beeper->input, EV_SND, SND_BELL);
 
 	beeper->input->event = pwm_beeper_event;
+	beeper->input->close = pwm_beeper_close;
 
 	input_set_drvdata(beeper->input, beeper);
 
 	error = input_register_device(beeper->input);
 	if (error) {
-		dev_err(&pdev->dev, "Failed to register input device: %d\n", error);
-		goto err_input_free;
+		dev_err(dev, "Failed to register input device: %d\n", error);
+		return error;
 	}
 
 	platform_set_drvdata(pdev, beeper);
 
 	return 0;
-
-err_input_free:
-	input_free_device(beeper->input);
-err_pwm_free:
-	pwm_free(beeper->pwm);
-err_free:
-	kfree(beeper);
-
-	return error;
-}
-
-static int pwm_beeper_remove(struct platform_device *pdev)
-{
-	struct pwm_beeper *beeper = platform_get_drvdata(pdev);
-
-	input_unregister_device(beeper->input);
-
-	pwm_disable(beeper->pwm);
-	pwm_free(beeper->pwm);
-
-	kfree(beeper);
-
-	return 0;
 }
 
-#ifdef CONFIG_PM
 static int pwm_beeper_suspend(struct device *dev)
 {
 	struct pwm_beeper *beeper = dev_get_drvdata(dev);
 
-	if (beeper->period)
-		pwm_disable(beeper->pwm);
+	/*
+	 * Spinlock is taken here is not to protect write to
+	 * beeper->suspended, but to ensure that pwm_beeper_event
+	 * does not re-submit work once flag is set.
+	 */
+	scoped_guard(spinlock_irq, &beeper->input->event_lock) {
+		beeper->suspended = true;
+	}
+
+	pwm_beeper_stop(beeper);
 
 	return 0;
 }
@@ -158,36 +216,32 @@ static int pwm_beeper_resume(struct device *dev)
 {
 	struct pwm_beeper *beeper = dev_get_drvdata(dev);
 
-	if (beeper->period) {
-		pwm_config(beeper->pwm, beeper->period / 2, beeper->period);
-		pwm_enable(beeper->pwm);
+	scoped_guard(spinlock_irq, &beeper->input->event_lock) {
+		beeper->suspended = false;
 	}
 
+	/* Let worker figure out if we should resume beeping */
+	schedule_work(&beeper->work);
+
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
-			 pwm_beeper_suspend, pwm_beeper_resume);
-
-#define PWM_BEEPER_PM_OPS (&pwm_beeper_pm_ops)
-#else
-#define PWM_BEEPER_PM_OPS NULL
-#endif
+static DEFINE_SIMPLE_DEV_PM_OPS(pwm_beeper_pm_ops,
+				pwm_beeper_suspend, pwm_beeper_resume);
 
 #ifdef CONFIG_OF
 static const struct of_device_id pwm_beeper_match[] = {
 	{ .compatible = "pwm-beeper", },
 	{ },
 };
+MODULE_DEVICE_TABLE(of, pwm_beeper_match);
 #endif
 
 static struct platform_driver pwm_beeper_driver = {
 	.probe	= pwm_beeper_probe,
-	.remove = pwm_beeper_remove,
 	.driver = {
 		.name	= "pwm-beeper",
-		.owner	= THIS_MODULE,
-		.pm	= PWM_BEEPER_PM_OPS,
+		.pm	= pm_sleep_ptr(&pwm_beeper_pm_ops),
 		.of_match_table = of_match_ptr(pwm_beeper_match),
 	},
 };