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200 lines
4.4 KiB
200 lines
4.4 KiB
// 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 <[email protected]> |
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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 <[email protected]>"); |
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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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