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![Linus Walleij](/assets/img/avatar_default.png)
The regulator LED can easily be adapted to probe from the device tree. We switch led_classdev_register() to led_classdev_register_ext() passing some struct led_init_data init_data that we leave NULL save the fwnode if platform data isn't present so that it will be populated from the device tree. If we have platform data we set up the name from the platform data but using init_data instead. Cc: Antonio Ospite <ao2@ao2.it> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Pavel Machek <pavel@ucw.cz>
205 lines
4.5 KiB
C
205 lines
4.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* leds-regulator.c - LED class driver for regulator driven LEDs.
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*
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* Copyright (C) 2009 Antonio Ospite <ospite@studenti.unina.it>
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*
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* Inspired by leds-wm8350 driver.
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*/
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/leds.h>
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#include <linux/leds-regulator.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/consumer.h>
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#define to_regulator_led(led_cdev) \
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container_of(led_cdev, struct regulator_led, cdev)
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struct regulator_led {
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struct led_classdev cdev;
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int enabled;
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struct mutex mutex;
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struct regulator *vcc;
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};
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static inline int led_regulator_get_max_brightness(struct regulator *supply)
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{
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int ret;
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int voltage = regulator_list_voltage(supply, 0);
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if (voltage <= 0)
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return 1;
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/* even if regulator can't change voltages,
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* we still assume it can change status
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* and the LED can be turned on and off.
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*/
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ret = regulator_set_voltage(supply, voltage, voltage);
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if (ret < 0)
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return 1;
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return regulator_count_voltages(supply);
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}
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static int led_regulator_get_voltage(struct regulator *supply,
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enum led_brightness brightness)
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{
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if (brightness == 0)
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return -EINVAL;
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return regulator_list_voltage(supply, brightness - 1);
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}
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static void regulator_led_enable(struct regulator_led *led)
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{
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int ret;
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if (led->enabled)
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return;
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ret = regulator_enable(led->vcc);
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if (ret != 0) {
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dev_err(led->cdev.dev, "Failed to enable vcc: %d\n", ret);
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return;
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}
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led->enabled = 1;
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}
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static void regulator_led_disable(struct regulator_led *led)
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{
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int ret;
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if (!led->enabled)
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return;
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ret = regulator_disable(led->vcc);
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if (ret != 0) {
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dev_err(led->cdev.dev, "Failed to disable vcc: %d\n", ret);
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return;
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}
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led->enabled = 0;
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}
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static int regulator_led_brightness_set(struct led_classdev *led_cdev,
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enum led_brightness value)
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{
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struct regulator_led *led = to_regulator_led(led_cdev);
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int voltage;
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int ret = 0;
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mutex_lock(&led->mutex);
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if (value == LED_OFF) {
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regulator_led_disable(led);
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goto out;
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}
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if (led->cdev.max_brightness > 1) {
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voltage = led_regulator_get_voltage(led->vcc, value);
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dev_dbg(led->cdev.dev, "brightness: %d voltage: %d\n",
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value, voltage);
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ret = regulator_set_voltage(led->vcc, voltage, voltage);
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if (ret != 0)
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dev_err(led->cdev.dev, "Failed to set voltage %d: %d\n",
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voltage, ret);
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}
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regulator_led_enable(led);
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out:
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mutex_unlock(&led->mutex);
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return ret;
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}
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static int regulator_led_probe(struct platform_device *pdev)
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{
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struct led_regulator_platform_data *pdata =
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dev_get_platdata(&pdev->dev);
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struct device *dev = &pdev->dev;
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struct led_init_data init_data = {};
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struct regulator_led *led;
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struct regulator *vcc;
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int ret = 0;
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vcc = devm_regulator_get_exclusive(dev, "vled");
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if (IS_ERR(vcc)) {
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dev_err(dev, "Cannot get vcc\n");
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return PTR_ERR(vcc);
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}
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led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
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if (led == NULL)
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return -ENOMEM;
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init_data.fwnode = dev->fwnode;
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led->cdev.max_brightness = led_regulator_get_max_brightness(vcc);
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/* Legacy platform data label assignment */
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if (pdata) {
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if (pdata->brightness > led->cdev.max_brightness) {
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dev_err(dev, "Invalid default brightness %d\n",
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pdata->brightness);
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return -EINVAL;
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}
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led->cdev.brightness = pdata->brightness;
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init_data.default_label = pdata->name;
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}
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led->cdev.brightness_set_blocking = regulator_led_brightness_set;
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led->cdev.flags |= LED_CORE_SUSPENDRESUME;
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led->vcc = vcc;
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/* to handle correctly an already enabled regulator */
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if (regulator_is_enabled(led->vcc))
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led->enabled = 1;
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mutex_init(&led->mutex);
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platform_set_drvdata(pdev, led);
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ret = led_classdev_register_ext(dev, &led->cdev, &init_data);
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if (ret < 0)
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return ret;
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return 0;
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}
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static int regulator_led_remove(struct platform_device *pdev)
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{
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struct regulator_led *led = platform_get_drvdata(pdev);
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led_classdev_unregister(&led->cdev);
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regulator_led_disable(led);
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return 0;
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}
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static const struct of_device_id regulator_led_of_match[] = {
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{ .compatible = "regulator-led", },
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{}
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};
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MODULE_DEVICE_TABLE(of, regulator_led_of_match);
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static struct platform_driver regulator_led_driver = {
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.driver = {
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.name = "leds-regulator",
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.of_match_table = regulator_led_of_match,
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},
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.probe = regulator_led_probe,
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.remove = regulator_led_remove,
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};
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module_platform_driver(regulator_led_driver);
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MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
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MODULE_DESCRIPTION("Regulator driven LED driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:leds-regulator");
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