162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-only
262306a36Sopenharmony_ci/*
362306a36Sopenharmony_ci * leds-regulator.c - LED class driver for regulator driven LEDs.
462306a36Sopenharmony_ci *
562306a36Sopenharmony_ci * Copyright (C) 2009 Antonio Ospite <ospite@studenti.unina.it>
662306a36Sopenharmony_ci *
762306a36Sopenharmony_ci * Inspired by leds-wm8350 driver.
862306a36Sopenharmony_ci */
962306a36Sopenharmony_ci
1062306a36Sopenharmony_ci#include <linux/module.h>
1162306a36Sopenharmony_ci#include <linux/mod_devicetable.h>
1262306a36Sopenharmony_ci#include <linux/err.h>
1362306a36Sopenharmony_ci#include <linux/slab.h>
1462306a36Sopenharmony_ci#include <linux/leds.h>
1562306a36Sopenharmony_ci#include <linux/leds-regulator.h>
1662306a36Sopenharmony_ci#include <linux/platform_device.h>
1762306a36Sopenharmony_ci#include <linux/regulator/consumer.h>
1862306a36Sopenharmony_ci
1962306a36Sopenharmony_ci#define to_regulator_led(led_cdev) \
2062306a36Sopenharmony_ci	container_of(led_cdev, struct regulator_led, cdev)
2162306a36Sopenharmony_ci
2262306a36Sopenharmony_cistruct regulator_led {
2362306a36Sopenharmony_ci	struct led_classdev cdev;
2462306a36Sopenharmony_ci	int enabled;
2562306a36Sopenharmony_ci	struct mutex mutex;
2662306a36Sopenharmony_ci
2762306a36Sopenharmony_ci	struct regulator *vcc;
2862306a36Sopenharmony_ci};
2962306a36Sopenharmony_ci
3062306a36Sopenharmony_cistatic inline int led_regulator_get_max_brightness(struct regulator *supply)
3162306a36Sopenharmony_ci{
3262306a36Sopenharmony_ci	int ret;
3362306a36Sopenharmony_ci	int voltage = regulator_list_voltage(supply, 0);
3462306a36Sopenharmony_ci
3562306a36Sopenharmony_ci	if (voltage <= 0)
3662306a36Sopenharmony_ci		return 1;
3762306a36Sopenharmony_ci
3862306a36Sopenharmony_ci	/* even if regulator can't change voltages,
3962306a36Sopenharmony_ci	 * we still assume it can change status
4062306a36Sopenharmony_ci	 * and the LED can be turned on and off.
4162306a36Sopenharmony_ci	 */
4262306a36Sopenharmony_ci	ret = regulator_set_voltage(supply, voltage, voltage);
4362306a36Sopenharmony_ci	if (ret < 0)
4462306a36Sopenharmony_ci		return 1;
4562306a36Sopenharmony_ci
4662306a36Sopenharmony_ci	return regulator_count_voltages(supply);
4762306a36Sopenharmony_ci}
4862306a36Sopenharmony_ci
4962306a36Sopenharmony_cistatic int led_regulator_get_voltage(struct regulator *supply,
5062306a36Sopenharmony_ci		enum led_brightness brightness)
5162306a36Sopenharmony_ci{
5262306a36Sopenharmony_ci	if (brightness == 0)
5362306a36Sopenharmony_ci		return -EINVAL;
5462306a36Sopenharmony_ci
5562306a36Sopenharmony_ci	return regulator_list_voltage(supply, brightness - 1);
5662306a36Sopenharmony_ci}
5762306a36Sopenharmony_ci
5862306a36Sopenharmony_ci
5962306a36Sopenharmony_cistatic void regulator_led_enable(struct regulator_led *led)
6062306a36Sopenharmony_ci{
6162306a36Sopenharmony_ci	int ret;
6262306a36Sopenharmony_ci
6362306a36Sopenharmony_ci	if (led->enabled)
6462306a36Sopenharmony_ci		return;
6562306a36Sopenharmony_ci
6662306a36Sopenharmony_ci	ret = regulator_enable(led->vcc);
6762306a36Sopenharmony_ci	if (ret != 0) {
6862306a36Sopenharmony_ci		dev_err(led->cdev.dev, "Failed to enable vcc: %d\n", ret);
6962306a36Sopenharmony_ci		return;
7062306a36Sopenharmony_ci	}
7162306a36Sopenharmony_ci
7262306a36Sopenharmony_ci	led->enabled = 1;
7362306a36Sopenharmony_ci}
7462306a36Sopenharmony_ci
7562306a36Sopenharmony_cistatic void regulator_led_disable(struct regulator_led *led)
7662306a36Sopenharmony_ci{
7762306a36Sopenharmony_ci	int ret;
7862306a36Sopenharmony_ci
7962306a36Sopenharmony_ci	if (!led->enabled)
8062306a36Sopenharmony_ci		return;
8162306a36Sopenharmony_ci
8262306a36Sopenharmony_ci	ret = regulator_disable(led->vcc);
8362306a36Sopenharmony_ci	if (ret != 0) {
8462306a36Sopenharmony_ci		dev_err(led->cdev.dev, "Failed to disable vcc: %d\n", ret);
8562306a36Sopenharmony_ci		return;
8662306a36Sopenharmony_ci	}
8762306a36Sopenharmony_ci
8862306a36Sopenharmony_ci	led->enabled = 0;
8962306a36Sopenharmony_ci}
9062306a36Sopenharmony_ci
9162306a36Sopenharmony_cistatic int regulator_led_brightness_set(struct led_classdev *led_cdev,
9262306a36Sopenharmony_ci					 enum led_brightness value)
9362306a36Sopenharmony_ci{
9462306a36Sopenharmony_ci	struct regulator_led *led = to_regulator_led(led_cdev);
9562306a36Sopenharmony_ci	int voltage;
9662306a36Sopenharmony_ci	int ret = 0;
9762306a36Sopenharmony_ci
9862306a36Sopenharmony_ci	mutex_lock(&led->mutex);
9962306a36Sopenharmony_ci
10062306a36Sopenharmony_ci	if (value == LED_OFF) {
10162306a36Sopenharmony_ci		regulator_led_disable(led);
10262306a36Sopenharmony_ci		goto out;
10362306a36Sopenharmony_ci	}
10462306a36Sopenharmony_ci
10562306a36Sopenharmony_ci	if (led->cdev.max_brightness > 1) {
10662306a36Sopenharmony_ci		voltage = led_regulator_get_voltage(led->vcc, value);
10762306a36Sopenharmony_ci		dev_dbg(led->cdev.dev, "brightness: %d voltage: %d\n",
10862306a36Sopenharmony_ci				value, voltage);
10962306a36Sopenharmony_ci
11062306a36Sopenharmony_ci		ret = regulator_set_voltage(led->vcc, voltage, voltage);
11162306a36Sopenharmony_ci		if (ret != 0)
11262306a36Sopenharmony_ci			dev_err(led->cdev.dev, "Failed to set voltage %d: %d\n",
11362306a36Sopenharmony_ci				voltage, ret);
11462306a36Sopenharmony_ci	}
11562306a36Sopenharmony_ci
11662306a36Sopenharmony_ci	regulator_led_enable(led);
11762306a36Sopenharmony_ci
11862306a36Sopenharmony_ciout:
11962306a36Sopenharmony_ci	mutex_unlock(&led->mutex);
12062306a36Sopenharmony_ci	return ret;
12162306a36Sopenharmony_ci}
12262306a36Sopenharmony_ci
12362306a36Sopenharmony_cistatic int regulator_led_probe(struct platform_device *pdev)
12462306a36Sopenharmony_ci{
12562306a36Sopenharmony_ci	struct led_regulator_platform_data *pdata =
12662306a36Sopenharmony_ci			dev_get_platdata(&pdev->dev);
12762306a36Sopenharmony_ci	struct device *dev = &pdev->dev;
12862306a36Sopenharmony_ci	struct led_init_data init_data = {};
12962306a36Sopenharmony_ci	struct regulator_led *led;
13062306a36Sopenharmony_ci	struct regulator *vcc;
13162306a36Sopenharmony_ci	int ret = 0;
13262306a36Sopenharmony_ci
13362306a36Sopenharmony_ci	vcc = devm_regulator_get_exclusive(dev, "vled");
13462306a36Sopenharmony_ci	if (IS_ERR(vcc)) {
13562306a36Sopenharmony_ci		dev_err(dev, "Cannot get vcc\n");
13662306a36Sopenharmony_ci		return PTR_ERR(vcc);
13762306a36Sopenharmony_ci	}
13862306a36Sopenharmony_ci
13962306a36Sopenharmony_ci	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
14062306a36Sopenharmony_ci	if (led == NULL)
14162306a36Sopenharmony_ci		return -ENOMEM;
14262306a36Sopenharmony_ci
14362306a36Sopenharmony_ci	init_data.fwnode = dev->fwnode;
14462306a36Sopenharmony_ci
14562306a36Sopenharmony_ci	led->cdev.max_brightness = led_regulator_get_max_brightness(vcc);
14662306a36Sopenharmony_ci	/* Legacy platform data label assignment */
14762306a36Sopenharmony_ci	if (pdata) {
14862306a36Sopenharmony_ci		if (pdata->brightness > led->cdev.max_brightness) {
14962306a36Sopenharmony_ci			dev_err(dev, "Invalid default brightness %d\n",
15062306a36Sopenharmony_ci				pdata->brightness);
15162306a36Sopenharmony_ci			return -EINVAL;
15262306a36Sopenharmony_ci		}
15362306a36Sopenharmony_ci		led->cdev.brightness = pdata->brightness;
15462306a36Sopenharmony_ci		init_data.default_label = pdata->name;
15562306a36Sopenharmony_ci	}
15662306a36Sopenharmony_ci
15762306a36Sopenharmony_ci	led->cdev.brightness_set_blocking = regulator_led_brightness_set;
15862306a36Sopenharmony_ci	led->cdev.flags |= LED_CORE_SUSPENDRESUME;
15962306a36Sopenharmony_ci	led->vcc = vcc;
16062306a36Sopenharmony_ci
16162306a36Sopenharmony_ci	/* to handle correctly an already enabled regulator */
16262306a36Sopenharmony_ci	if (regulator_is_enabled(led->vcc))
16362306a36Sopenharmony_ci		led->enabled = 1;
16462306a36Sopenharmony_ci
16562306a36Sopenharmony_ci	mutex_init(&led->mutex);
16662306a36Sopenharmony_ci
16762306a36Sopenharmony_ci	platform_set_drvdata(pdev, led);
16862306a36Sopenharmony_ci
16962306a36Sopenharmony_ci	ret = led_classdev_register_ext(dev, &led->cdev, &init_data);
17062306a36Sopenharmony_ci	if (ret < 0)
17162306a36Sopenharmony_ci		return ret;
17262306a36Sopenharmony_ci
17362306a36Sopenharmony_ci	return 0;
17462306a36Sopenharmony_ci}
17562306a36Sopenharmony_ci
17662306a36Sopenharmony_cistatic int regulator_led_remove(struct platform_device *pdev)
17762306a36Sopenharmony_ci{
17862306a36Sopenharmony_ci	struct regulator_led *led = platform_get_drvdata(pdev);
17962306a36Sopenharmony_ci
18062306a36Sopenharmony_ci	led_classdev_unregister(&led->cdev);
18162306a36Sopenharmony_ci	regulator_led_disable(led);
18262306a36Sopenharmony_ci	return 0;
18362306a36Sopenharmony_ci}
18462306a36Sopenharmony_ci
18562306a36Sopenharmony_cistatic const struct of_device_id regulator_led_of_match[] = {
18662306a36Sopenharmony_ci	{ .compatible = "regulator-led", },
18762306a36Sopenharmony_ci	{}
18862306a36Sopenharmony_ci};
18962306a36Sopenharmony_ciMODULE_DEVICE_TABLE(of, regulator_led_of_match);
19062306a36Sopenharmony_ci
19162306a36Sopenharmony_cistatic struct platform_driver regulator_led_driver = {
19262306a36Sopenharmony_ci	.driver = {
19362306a36Sopenharmony_ci		.name  = "leds-regulator",
19462306a36Sopenharmony_ci		.of_match_table = regulator_led_of_match,
19562306a36Sopenharmony_ci	},
19662306a36Sopenharmony_ci	.probe  = regulator_led_probe,
19762306a36Sopenharmony_ci	.remove = regulator_led_remove,
19862306a36Sopenharmony_ci};
19962306a36Sopenharmony_ci
20062306a36Sopenharmony_cimodule_platform_driver(regulator_led_driver);
20162306a36Sopenharmony_ci
20262306a36Sopenharmony_ciMODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
20362306a36Sopenharmony_ciMODULE_DESCRIPTION("Regulator driven LED driver");
20462306a36Sopenharmony_ciMODULE_LICENSE("GPL");
20562306a36Sopenharmony_ciMODULE_ALIAS("platform:leds-regulator");
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