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![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 2 normalized pattern(s): 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 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 # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
200 lines
4.4 KiB
C
200 lines
4.4 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/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 regulator_led *led;
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struct regulator *vcc;
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int ret = 0;
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if (pdata == NULL) {
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dev_err(&pdev->dev, "no platform data\n");
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return -ENODEV;
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}
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vcc = devm_regulator_get_exclusive(&pdev->dev, "vled");
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if (IS_ERR(vcc)) {
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dev_err(&pdev->dev, "Cannot get vcc for %s\n", pdata->name);
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return PTR_ERR(vcc);
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}
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led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
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if (led == NULL)
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return -ENOMEM;
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led->cdev.max_brightness = led_regulator_get_max_brightness(vcc);
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if (pdata->brightness > led->cdev.max_brightness) {
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dev_err(&pdev->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_set_blocking = regulator_led_brightness_set;
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led->cdev.name = pdata->name;
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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(&pdev->dev, &led->cdev);
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if (ret < 0)
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return ret;
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/* to expose the default value to userspace */
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led->cdev.brightness = pdata->brightness;
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/* Set the default led status */
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regulator_led_brightness_set(&led->cdev, led->cdev.brightness);
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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 struct platform_driver regulator_led_driver = {
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.driver = {
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.name = "leds-regulator",
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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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