1 files changed, 169 insertions, 164 deletions

diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
index faf52c005e8c..6c1f2f50ff85 100644
--- a/drivers/leds/leds-pwm.c
+++ b/drivers/leds/leds-pwm.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/drivers/leds-pwm.c
  *
@@ -6,216 +7,222 @@
  * Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de)
  *
  * based on leds-gpio.c by Raphael Assenat <raph@8d.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
  */
 
-#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
 #include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/platform_device.h>
-#include <linux/of_platform.h>
-#include <linux/fb.h>
 #include <linux/leds.h>
-#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
 #include <linux/pwm.h>
-#include <linux/leds_pwm.h>
 #include <linux/slab.h>
-#include <linux/workqueue.h>
+
+struct led_pwm {
+	const char	*name;
+	u8		active_low;
+	u8		default_state;
+	unsigned int	max_brightness;
+};
 
 struct led_pwm_data {
+	struct gpio_desc	*enable_gpio;
 	struct led_classdev	cdev;
 	struct pwm_device	*pwm;
-	struct work_struct	work;
+	struct pwm_state	pwmstate;
 	unsigned int		active_low;
-	unsigned int		period;
-	int			duty;
-	bool			can_sleep;
 };
 
 struct led_pwm_priv {
 	int num_leds;
-	struct led_pwm_data leds[0];
+	struct led_pwm_data leds[];
 };
 
-static void __led_pwm_set(struct led_pwm_data *led_dat)
+static int led_pwm_set(struct led_classdev *led_cdev,
+		       enum led_brightness brightness)
 {
-	int new_duty = led_dat->duty;
+	struct led_pwm_data *led_dat =
+		container_of(led_cdev, struct led_pwm_data, cdev);
+	unsigned int max = led_dat->cdev.max_brightness;
+	unsigned long long duty = led_dat->pwmstate.period;
 
-	pwm_config(led_dat->pwm, new_duty, led_dat->period);
+	duty *= brightness;
+	do_div(duty, max);
 
-	if (new_duty == 0)
-		pwm_disable(led_dat->pwm);
-	else
-		pwm_enable(led_dat->pwm);
-}
+	if (led_dat->active_low)
+		duty = led_dat->pwmstate.period - duty;
 
-static void led_pwm_work(struct work_struct *work)
-{
-	struct led_pwm_data *led_dat =
-		container_of(work, struct led_pwm_data, work);
+	gpiod_set_value_cansleep(led_dat->enable_gpio, !!brightness);
 
-	__led_pwm_set(led_dat);
+	led_dat->pwmstate.duty_cycle = duty;
+	/*
+	 * Disabling a PWM doesn't guarantee that it emits the inactive level.
+	 * So keep it on. Only for suspending the PWM should be disabled because
+	 * otherwise it refuses to suspend. The possible downside is that the
+	 * LED might stay (or even go) on.
+	 */
+	led_dat->pwmstate.enabled = !(led_cdev->flags & LED_SUSPENDED);
+	return pwm_apply_might_sleep(led_dat->pwm, &led_dat->pwmstate);
 }
 
-static void led_pwm_set(struct led_classdev *led_cdev,
-	enum led_brightness brightness)
+static int led_pwm_default_brightness_get(struct fwnode_handle *fwnode,
+					  int max_brightness)
 {
-	struct led_pwm_data *led_dat =
-		container_of(led_cdev, struct led_pwm_data, cdev);
-	unsigned int max = led_dat->cdev.max_brightness;
-	unsigned int period =  led_dat->period;
+	unsigned int default_brightness;
+	int ret;
 
-	led_dat->duty = brightness * period / max;
+	ret = fwnode_property_read_u32(fwnode, "default-brightness",
+				       &default_brightness);
+	if (ret < 0 || default_brightness > max_brightness)
+		default_brightness = max_brightness;
 
-	if (led_dat->can_sleep)
-		schedule_work(&led_dat->work);
-	else
-		__led_pwm_set(led_dat);
+	return default_brightness;
 }
 
-static inline size_t sizeof_pwm_leds_priv(int num_leds)
+__attribute__((nonnull))
+static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
+		       struct led_pwm *led, struct fwnode_handle *fwnode)
 {
-	return sizeof(struct led_pwm_priv) +
-		      (sizeof(struct led_pwm_data) * num_leds);
+	struct led_pwm_data *led_data = &priv->leds[priv->num_leds];
+	struct led_init_data init_data = { .fwnode = fwnode };
+	int ret;
+
+	led_data->active_low = led->active_low;
+	led_data->cdev.name = led->name;
+	led_data->cdev.brightness = LED_OFF;
+	led_data->cdev.max_brightness = led->max_brightness;
+	led_data->cdev.flags = LED_CORE_SUSPENDRESUME;
+
+	led_data->pwm = devm_fwnode_pwm_get(dev, fwnode, NULL);
+	if (IS_ERR(led_data->pwm))
+		return dev_err_probe(dev, PTR_ERR(led_data->pwm),
+				     "unable to request PWM for %s\n",
+				     led->name);
+
+	led_data->cdev.brightness_set_blocking = led_pwm_set;
+
+	/* init PWM state */
+	switch (led->default_state) {
+	case LEDS_DEFSTATE_KEEP:
+		pwm_get_state(led_data->pwm, &led_data->pwmstate);
+		if (led_data->pwmstate.period)
+			break;
+		led->default_state = LEDS_DEFSTATE_OFF;
+		dev_warn(dev,
+			"failed to read period for %s, default to off",
+			led->name);
+		fallthrough;
+	default:
+		pwm_init_state(led_data->pwm, &led_data->pwmstate);
+		break;
+	}
+
+	/* set brightness */
+	switch (led->default_state) {
+	case LEDS_DEFSTATE_ON:
+		led_data->cdev.brightness =
+			led_pwm_default_brightness_get(fwnode, led->max_brightness);
+		break;
+	case LEDS_DEFSTATE_KEEP:
+		{
+		uint64_t brightness;
+
+		brightness = led->max_brightness;
+		brightness *= led_data->pwmstate.duty_cycle;
+		do_div(brightness, led_data->pwmstate.period);
+		led_data->cdev.brightness = brightness;
+		}
+		break;
+	}
+
+	/*
+	 * Claim the GPIO as GPIOD_ASIS and set the value
+	 * later on to honor the different default states
+	 */
+	led_data->enable_gpio = devm_fwnode_gpiod_get(dev, fwnode, "enable", GPIOD_ASIS, NULL);
+	if (IS_ERR(led_data->enable_gpio)) {
+		if (PTR_ERR(led_data->enable_gpio) == -ENOENT)
+			/* Enable GPIO is optional */
+			led_data->enable_gpio = NULL;
+		else
+			return PTR_ERR(led_data->enable_gpio);
+	}
+
+	gpiod_direction_output(led_data->enable_gpio, !!led_data->cdev.brightness);
+
+	ret = devm_led_classdev_register_ext(dev, &led_data->cdev, &init_data);
+	if (ret) {
+		dev_err(dev, "failed to register PWM led for %s: %d\n",
+			led->name, ret);
+		return ret;
+	}
+
+	if (led->default_state != LEDS_DEFSTATE_KEEP) {
+		ret = led_pwm_set(&led_data->cdev, led_data->cdev.brightness);
+		if (ret) {
+			dev_err(dev, "failed to set led PWM value for %s: %d",
+				led->name, ret);
+			return ret;
+		}
+	}
+
+	priv->num_leds++;
+	return 0;
 }
 
-static struct led_pwm_priv *led_pwm_create_of(struct platform_device *pdev)
+static int led_pwm_create_fwnode(struct device *dev, struct led_pwm_priv *priv)
 {
-	struct device_node *node = pdev->dev.of_node;
-	struct device_node *child;
-	struct led_pwm_priv *priv;
-	int count, ret;
+	struct led_pwm led;
+	int ret;
 
-	/* count LEDs in this device, so we know how much to allocate */
-	count = of_get_child_count(node);
-	if (!count)
-		return NULL;
+	device_for_each_child_node_scoped(dev, fwnode) {
+		memset(&led, 0, sizeof(led));
 
-	priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count),
-			    GFP_KERNEL);
-	if (!priv)
-		return NULL;
+		ret = fwnode_property_read_string(fwnode, "label", &led.name);
+		if (ret && is_of_node(fwnode))
+			led.name = to_of_node(fwnode)->name;
 
-	for_each_child_of_node(node, child) {
-		struct led_pwm_data *led_dat = &priv->leds[priv->num_leds];
+		if (!led.name)
+			return -EINVAL;
 
-		led_dat->cdev.name = of_get_property(child, "label",
-						     NULL) ? : child->name;
+		led.active_low = fwnode_property_read_bool(fwnode,
+							   "active-low");
+		fwnode_property_read_u32(fwnode, "max-brightness",
+					 &led.max_brightness);
 
-		led_dat->pwm = devm_of_pwm_get(&pdev->dev, child, NULL);
-		if (IS_ERR(led_dat->pwm)) {
-			dev_err(&pdev->dev, "unable to request PWM for %s\n",
-				led_dat->cdev.name);
-			goto err;
-		}
-		/* Get the period from PWM core when n*/
-		led_dat->period = pwm_get_period(led_dat->pwm);
-
-		led_dat->cdev.default_trigger = of_get_property(child,
-						"linux,default-trigger", NULL);
-		of_property_read_u32(child, "max-brightness",
-				     &led_dat->cdev.max_brightness);
-
-		led_dat->cdev.brightness_set = led_pwm_set;
-		led_dat->cdev.brightness = LED_OFF;
-		led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
-
-		led_dat->can_sleep = pwm_can_sleep(led_dat->pwm);
-		if (led_dat->can_sleep)
-			INIT_WORK(&led_dat->work, led_pwm_work);
-
-		ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
-		if (ret < 0) {
-			dev_err(&pdev->dev, "failed to register for %s\n",
-				led_dat->cdev.name);
-			of_node_put(child);
-			goto err;
-		}
-		priv->num_leds++;
-	}
+		led.default_state = led_init_default_state_get(fwnode);
 
-	return priv;
-err:
-	while (priv->num_leds--)
-		led_classdev_unregister(&priv->leds[priv->num_leds].cdev);
+		ret = led_pwm_add(dev, priv, &led, fwnode);
+		if (ret)
+			return ret;
+	}
 
-	return NULL;
+	return 0;
 }
 
 static int led_pwm_probe(struct platform_device *pdev)
 {
-	struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
 	struct led_pwm_priv *priv;
-	int i, ret = 0;
-
-	if (pdata && pdata->num_leds) {
-		priv = devm_kzalloc(&pdev->dev,
-				    sizeof_pwm_leds_priv(pdata->num_leds),
-				    GFP_KERNEL);
-		if (!priv)
-			return -ENOMEM;
-
-		for (i = 0; i < pdata->num_leds; i++) {
-			struct led_pwm *cur_led = &pdata->leds[i];
-			struct led_pwm_data *led_dat = &priv->leds[i];
-
-			led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name);
-			if (IS_ERR(led_dat->pwm)) {
-				ret = PTR_ERR(led_dat->pwm);
-				dev_err(&pdev->dev,
-					"unable to request PWM for %s\n",
-					cur_led->name);
-				goto err;
-			}
-
-			led_dat->cdev.name = cur_led->name;
-			led_dat->cdev.default_trigger = cur_led->default_trigger;
-			led_dat->active_low = cur_led->active_low;
-			led_dat->period = cur_led->pwm_period_ns;
-			led_dat->cdev.brightness_set = led_pwm_set;
-			led_dat->cdev.brightness = LED_OFF;
-			led_dat->cdev.max_brightness = cur_led->max_brightness;
-			led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
-
-			led_dat->can_sleep = pwm_can_sleep(led_dat->pwm);
-			if (led_dat->can_sleep)
-				INIT_WORK(&led_dat->work, led_pwm_work);
-
-			ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
-			if (ret < 0)
-				goto err;
-		}
-		priv->num_leds = pdata->num_leds;
-	} else {
-		priv = led_pwm_create_of(pdev);
-		if (!priv)
-			return -ENODEV;
-	}
+	int ret = 0;
+	int count;
 
-	platform_set_drvdata(pdev, priv);
+	count = device_get_child_node_count(&pdev->dev);
 
-	return 0;
+	if (!count)
+		return -EINVAL;
 
-err:
-	while (i--)
-		led_classdev_unregister(&priv->leds[i].cdev);
+	priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, count),
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
 
-	return ret;
-}
+	ret = led_pwm_create_fwnode(&pdev->dev, priv);
 
-static int led_pwm_remove(struct platform_device *pdev)
-{
-	struct led_pwm_priv *priv = platform_get_drvdata(pdev);
-	int i;
+	if (ret)
+		return ret;
 
-	for (i = 0; i < priv->num_leds; i++) {
-		led_classdev_unregister(&priv->leds[i].cdev);
-		if (priv->leds[i].can_sleep)
-			cancel_work_sync(&priv->leds[i].work);
-	}
+	platform_set_drvdata(pdev, priv);
 
 	return 0;
 }
@@ -228,17 +235,15 @@ MODULE_DEVICE_TABLE(of, of_pwm_leds_match);
 
 static struct platform_driver led_pwm_driver = {
 	.probe		= led_pwm_probe,
-	.remove		= led_pwm_remove,
 	.driver		= {
 		.name	= "leds_pwm",
-		.owner	= THIS_MODULE,
-		.of_match_table = of_match_ptr(of_pwm_leds_match),
+		.of_match_table = of_pwm_leds_match,
 	},
 };
 
 module_platform_driver(led_pwm_driver);
 
 MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
-MODULE_DESCRIPTION("PWM LED driver for PXA");
-MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("generic PWM LED driver");
+MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:leds-pwm");